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WSL2-Linux-Kernel/drivers/tty/serial/sh-sci.c

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C
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/*
* SuperH on-chip serial module support. (SCI with no FIFO / with FIFO)
*
* Copyright (C) 2002 - 2011 Paul Mundt
* Copyright (C) 2015 Glider bvba
* Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007).
*
* based off of the old drivers/char/sh-sci.c by:
*
* Copyright (C) 1999, 2000 Niibe Yutaka
* Copyright (C) 2000 Sugioka Toshinobu
* Modified to support multiple serial ports. Stuart Menefy (May 2000).
* Modified to support SecureEdge. David McCullough (2002)
* Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003).
* Removed SH7300 support (Jul 2007).
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif
#undef DEBUG
#include <linux/clk.h>
#include <linux/console.h>
#include <linux/ctype.h>
#include <linux/cpufreq.h>
#include <linux/delay.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/major.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/scatterlist.h>
#include <linux/serial.h>
#include <linux/serial_sci.h>
#include <linux/sh_dma.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/sysrq.h>
#include <linux/timer.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#ifdef CONFIG_SUPERH
#include <asm/sh_bios.h>
#endif
#include "sh-sci.h"
/* Offsets into the sci_port->irqs array */
enum {
SCIx_ERI_IRQ,
SCIx_RXI_IRQ,
SCIx_TXI_IRQ,
SCIx_BRI_IRQ,
SCIx_NR_IRQS,
SCIx_MUX_IRQ = SCIx_NR_IRQS, /* special case */
};
#define SCIx_IRQ_IS_MUXED(port) \
((port)->irqs[SCIx_ERI_IRQ] == \
(port)->irqs[SCIx_RXI_IRQ]) || \
((port)->irqs[SCIx_ERI_IRQ] && \
((port)->irqs[SCIx_RXI_IRQ] < 0))
enum SCI_CLKS {
SCI_FCK, /* Functional Clock */
SCI_SCK, /* Optional External Clock */
SCI_BRG_INT, /* Optional BRG Internal Clock Source */
SCI_SCIF_CLK, /* Optional BRG External Clock Source */
SCI_NUM_CLKS
};
struct sci_port {
struct uart_port port;
/* Platform configuration */
struct plat_sci_port *cfg;
unsigned int overrun_reg;
unsigned int overrun_mask;
unsigned int error_mask;
unsigned int error_clear;
unsigned int sampling_rate;
resource_size_t reg_size;
/* Break timer */
struct timer_list break_timer;
int break_flag;
/* Clocks */
struct clk *clks[SCI_NUM_CLKS];
unsigned long clk_rates[SCI_NUM_CLKS];
int irqs[SCIx_NR_IRQS];
char *irqstr[SCIx_NR_IRQS];
struct dma_chan *chan_tx;
struct dma_chan *chan_rx;
#ifdef CONFIG_SERIAL_SH_SCI_DMA
dma_cookie_t cookie_tx;
dma_cookie_t cookie_rx[2];
dma_cookie_t active_rx;
dma_addr_t tx_dma_addr;
unsigned int tx_dma_len;
struct scatterlist sg_rx[2];
void *rx_buf[2];
size_t buf_len_rx;
struct work_struct work_tx;
struct timer_list rx_timer;
unsigned int rx_timeout;
#endif
};
#define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
static struct sci_port sci_ports[SCI_NPORTS];
static struct uart_driver sci_uart_driver;
static inline struct sci_port *
to_sci_port(struct uart_port *uart)
{
return container_of(uart, struct sci_port, port);
}
struct plat_sci_reg {
u8 offset, size;
};
/* Helper for invalidating specific entries of an inherited map. */
#define sci_reg_invalid { .offset = 0, .size = 0 }
static const struct plat_sci_reg sci_regmap[SCIx_NR_REGTYPES][SCIx_NR_REGS] = {
[SCIx_PROBE_REGTYPE] = {
[0 ... SCIx_NR_REGS - 1] = sci_reg_invalid,
},
/*
* Common SCI definitions, dependent on the port's regshift
* value.
*/
[SCIx_SCI_REGTYPE] = {
[SCSMR] = { 0x00, 8 },
[SCBRR] = { 0x01, 8 },
[SCSCR] = { 0x02, 8 },
[SCxTDR] = { 0x03, 8 },
[SCxSR] = { 0x04, 8 },
[SCxRDR] = { 0x05, 8 },
[SCFCR] = sci_reg_invalid,
[SCFDR] = sci_reg_invalid,
[SCTFDR] = sci_reg_invalid,
[SCRFDR] = sci_reg_invalid,
[SCSPTR] = sci_reg_invalid,
[SCLSR] = sci_reg_invalid,
[HSSRR] = sci_reg_invalid,
[SCPCR] = sci_reg_invalid,
[SCPDR] = sci_reg_invalid,
[SCDL] = sci_reg_invalid,
[SCCKS] = sci_reg_invalid,
},
/*
* Common definitions for legacy IrDA ports, dependent on
* regshift value.
*/
[SCIx_IRDA_REGTYPE] = {
[SCSMR] = { 0x00, 8 },
[SCBRR] = { 0x01, 8 },
[SCSCR] = { 0x02, 8 },
[SCxTDR] = { 0x03, 8 },
[SCxSR] = { 0x04, 8 },
[SCxRDR] = { 0x05, 8 },
[SCFCR] = { 0x06, 8 },
[SCFDR] = { 0x07, 16 },
[SCTFDR] = sci_reg_invalid,
[SCRFDR] = sci_reg_invalid,
[SCSPTR] = sci_reg_invalid,
[SCLSR] = sci_reg_invalid,
[HSSRR] = sci_reg_invalid,
[SCPCR] = sci_reg_invalid,
[SCPDR] = sci_reg_invalid,
[SCDL] = sci_reg_invalid,
[SCCKS] = sci_reg_invalid,
},
/*
* Common SCIFA definitions.
*/
[SCIx_SCIFA_REGTYPE] = {
[SCSMR] = { 0x00, 16 },
[SCBRR] = { 0x04, 8 },
[SCSCR] = { 0x08, 16 },
[SCxTDR] = { 0x20, 8 },
[SCxSR] = { 0x14, 16 },
[SCxRDR] = { 0x24, 8 },
[SCFCR] = { 0x18, 16 },
[SCFDR] = { 0x1c, 16 },
[SCTFDR] = sci_reg_invalid,
[SCRFDR] = sci_reg_invalid,
[SCSPTR] = sci_reg_invalid,
[SCLSR] = sci_reg_invalid,
[HSSRR] = sci_reg_invalid,
[SCPCR] = { 0x30, 16 },
[SCPDR] = { 0x34, 16 },
[SCDL] = sci_reg_invalid,
[SCCKS] = sci_reg_invalid,
},
/*
* Common SCIFB definitions.
*/
[SCIx_SCIFB_REGTYPE] = {
[SCSMR] = { 0x00, 16 },
[SCBRR] = { 0x04, 8 },
[SCSCR] = { 0x08, 16 },
[SCxTDR] = { 0x40, 8 },
[SCxSR] = { 0x14, 16 },
[SCxRDR] = { 0x60, 8 },
[SCFCR] = { 0x18, 16 },
[SCFDR] = sci_reg_invalid,
[SCTFDR] = { 0x38, 16 },
[SCRFDR] = { 0x3c, 16 },
[SCSPTR] = sci_reg_invalid,
[SCLSR] = sci_reg_invalid,
[HSSRR] = sci_reg_invalid,
[SCPCR] = { 0x30, 16 },
[SCPDR] = { 0x34, 16 },
[SCDL] = sci_reg_invalid,
[SCCKS] = sci_reg_invalid,
},
/*
* Common SH-2(A) SCIF definitions for ports with FIFO data
* count registers.
*/
[SCIx_SH2_SCIF_FIFODATA_REGTYPE] = {
[SCSMR] = { 0x00, 16 },
[SCBRR] = { 0x04, 8 },
[SCSCR] = { 0x08, 16 },
[SCxTDR] = { 0x0c, 8 },
[SCxSR] = { 0x10, 16 },
[SCxRDR] = { 0x14, 8 },
[SCFCR] = { 0x18, 16 },
[SCFDR] = { 0x1c, 16 },
[SCTFDR] = sci_reg_invalid,
[SCRFDR] = sci_reg_invalid,
[SCSPTR] = { 0x20, 16 },
[SCLSR] = { 0x24, 16 },
[HSSRR] = sci_reg_invalid,
[SCPCR] = sci_reg_invalid,
[SCPDR] = sci_reg_invalid,
[SCDL] = sci_reg_invalid,
[SCCKS] = sci_reg_invalid,
},
/*
* Common SH-3 SCIF definitions.
*/
[SCIx_SH3_SCIF_REGTYPE] = {
[SCSMR] = { 0x00, 8 },
[SCBRR] = { 0x02, 8 },
[SCSCR] = { 0x04, 8 },
[SCxTDR] = { 0x06, 8 },
[SCxSR] = { 0x08, 16 },
[SCxRDR] = { 0x0a, 8 },
[SCFCR] = { 0x0c, 8 },
[SCFDR] = { 0x0e, 16 },
[SCTFDR] = sci_reg_invalid,
[SCRFDR] = sci_reg_invalid,
[SCSPTR] = sci_reg_invalid,
[SCLSR] = sci_reg_invalid,
[HSSRR] = sci_reg_invalid,
[SCPCR] = sci_reg_invalid,
[SCPDR] = sci_reg_invalid,
[SCDL] = sci_reg_invalid,
[SCCKS] = sci_reg_invalid,
},
/*
* Common SH-4(A) SCIF(B) definitions.
*/
[SCIx_SH4_SCIF_REGTYPE] = {
[SCSMR] = { 0x00, 16 },
[SCBRR] = { 0x04, 8 },
[SCSCR] = { 0x08, 16 },
[SCxTDR] = { 0x0c, 8 },
[SCxSR] = { 0x10, 16 },
[SCxRDR] = { 0x14, 8 },
[SCFCR] = { 0x18, 16 },
[SCFDR] = { 0x1c, 16 },
[SCTFDR] = sci_reg_invalid,
[SCRFDR] = sci_reg_invalid,
[SCSPTR] = { 0x20, 16 },
[SCLSR] = { 0x24, 16 },
[HSSRR] = sci_reg_invalid,
[SCPCR] = sci_reg_invalid,
[SCPDR] = sci_reg_invalid,
[SCDL] = sci_reg_invalid,
[SCCKS] = sci_reg_invalid,
},
/*
* Common SCIF definitions for ports with a Baud Rate Generator for
* External Clock (BRG).
*/
[SCIx_SH4_SCIF_BRG_REGTYPE] = {
[SCSMR] = { 0x00, 16 },
[SCBRR] = { 0x04, 8 },
[SCSCR] = { 0x08, 16 },
[SCxTDR] = { 0x0c, 8 },
[SCxSR] = { 0x10, 16 },
[SCxRDR] = { 0x14, 8 },
[SCFCR] = { 0x18, 16 },
[SCFDR] = { 0x1c, 16 },
[SCTFDR] = sci_reg_invalid,
[SCRFDR] = sci_reg_invalid,
[SCSPTR] = { 0x20, 16 },
[SCLSR] = { 0x24, 16 },
[HSSRR] = sci_reg_invalid,
[SCPCR] = sci_reg_invalid,
[SCPDR] = sci_reg_invalid,
[SCDL] = { 0x30, 16 },
[SCCKS] = { 0x34, 16 },
},
/*
* Common HSCIF definitions.
*/
[SCIx_HSCIF_REGTYPE] = {
[SCSMR] = { 0x00, 16 },
[SCBRR] = { 0x04, 8 },
[SCSCR] = { 0x08, 16 },
[SCxTDR] = { 0x0c, 8 },
[SCxSR] = { 0x10, 16 },
[SCxRDR] = { 0x14, 8 },
[SCFCR] = { 0x18, 16 },
[SCFDR] = { 0x1c, 16 },
[SCTFDR] = sci_reg_invalid,
[SCRFDR] = sci_reg_invalid,
[SCSPTR] = { 0x20, 16 },
[SCLSR] = { 0x24, 16 },
[HSSRR] = { 0x40, 16 },
[SCPCR] = sci_reg_invalid,
[SCPDR] = sci_reg_invalid,
[SCDL] = { 0x30, 16 },
[SCCKS] = { 0x34, 16 },
},
/*
* Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR
* register.
*/
[SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE] = {
[SCSMR] = { 0x00, 16 },
[SCBRR] = { 0x04, 8 },
[SCSCR] = { 0x08, 16 },
[SCxTDR] = { 0x0c, 8 },
[SCxSR] = { 0x10, 16 },
[SCxRDR] = { 0x14, 8 },
[SCFCR] = { 0x18, 16 },
[SCFDR] = { 0x1c, 16 },
[SCTFDR] = sci_reg_invalid,
[SCRFDR] = sci_reg_invalid,
[SCSPTR] = sci_reg_invalid,
[SCLSR] = { 0x24, 16 },
[HSSRR] = sci_reg_invalid,
[SCPCR] = sci_reg_invalid,
[SCPDR] = sci_reg_invalid,
[SCDL] = sci_reg_invalid,
[SCCKS] = sci_reg_invalid,
},
/*
* Common SH-4(A) SCIF(B) definitions for ports with FIFO data
* count registers.
*/
[SCIx_SH4_SCIF_FIFODATA_REGTYPE] = {
[SCSMR] = { 0x00, 16 },
[SCBRR] = { 0x04, 8 },
[SCSCR] = { 0x08, 16 },
[SCxTDR] = { 0x0c, 8 },
[SCxSR] = { 0x10, 16 },
[SCxRDR] = { 0x14, 8 },
[SCFCR] = { 0x18, 16 },
[SCFDR] = { 0x1c, 16 },
[SCTFDR] = { 0x1c, 16 }, /* aliased to SCFDR */
[SCRFDR] = { 0x20, 16 },
[SCSPTR] = { 0x24, 16 },
[SCLSR] = { 0x28, 16 },
[HSSRR] = sci_reg_invalid,
[SCPCR] = sci_reg_invalid,
[SCPDR] = sci_reg_invalid,
[SCDL] = sci_reg_invalid,
[SCCKS] = sci_reg_invalid,
},
/*
* SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR
* registers.
*/
[SCIx_SH7705_SCIF_REGTYPE] = {
[SCSMR] = { 0x00, 16 },
[SCBRR] = { 0x04, 8 },
[SCSCR] = { 0x08, 16 },
[SCxTDR] = { 0x20, 8 },
[SCxSR] = { 0x14, 16 },
[SCxRDR] = { 0x24, 8 },
[SCFCR] = { 0x18, 16 },
[SCFDR] = { 0x1c, 16 },
[SCTFDR] = sci_reg_invalid,
[SCRFDR] = sci_reg_invalid,
[SCSPTR] = sci_reg_invalid,
[SCLSR] = sci_reg_invalid,
[HSSRR] = sci_reg_invalid,
[SCPCR] = sci_reg_invalid,
[SCPDR] = sci_reg_invalid,
[SCDL] = sci_reg_invalid,
[SCCKS] = sci_reg_invalid,
},
};
#define sci_getreg(up, offset) (sci_regmap[to_sci_port(up)->cfg->regtype] + offset)
/*
* The "offset" here is rather misleading, in that it refers to an enum
* value relative to the port mapping rather than the fixed offset
* itself, which needs to be manually retrieved from the platform's
* register map for the given port.
*/
static unsigned int sci_serial_in(struct uart_port *p, int offset)
{
const struct plat_sci_reg *reg = sci_getreg(p, offset);
if (reg->size == 8)
return ioread8(p->membase + (reg->offset << p->regshift));
else if (reg->size == 16)
return ioread16(p->membase + (reg->offset << p->regshift));
else
WARN(1, "Invalid register access\n");
return 0;
}
static void sci_serial_out(struct uart_port *p, int offset, int value)
{
const struct plat_sci_reg *reg = sci_getreg(p, offset);
if (reg->size == 8)
iowrite8(value, p->membase + (reg->offset << p->regshift));
else if (reg->size == 16)
iowrite16(value, p->membase + (reg->offset << p->regshift));
else
WARN(1, "Invalid register access\n");
}
static int sci_probe_regmap(struct plat_sci_port *cfg)
{
switch (cfg->type) {
case PORT_SCI:
cfg->regtype = SCIx_SCI_REGTYPE;
break;
case PORT_IRDA:
cfg->regtype = SCIx_IRDA_REGTYPE;
break;
case PORT_SCIFA:
cfg->regtype = SCIx_SCIFA_REGTYPE;
break;
case PORT_SCIFB:
cfg->regtype = SCIx_SCIFB_REGTYPE;
break;
case PORT_SCIF:
/*
* The SH-4 is a bit of a misnomer here, although that's
* where this particular port layout originated. This
* configuration (or some slight variation thereof)
* remains the dominant model for all SCIFs.
*/
cfg->regtype = SCIx_SH4_SCIF_REGTYPE;
break;
case PORT_HSCIF:
cfg->regtype = SCIx_HSCIF_REGTYPE;
break;
default:
pr_err("Can't probe register map for given port\n");
return -EINVAL;
}
return 0;
}
static void sci_port_enable(struct sci_port *sci_port)
{
unsigned int i;
if (!sci_port->port.dev)
return;
pm_runtime_get_sync(sci_port->port.dev);
for (i = 0; i < SCI_NUM_CLKS; i++) {
clk_prepare_enable(sci_port->clks[i]);
sci_port->clk_rates[i] = clk_get_rate(sci_port->clks[i]);
}
sci_port->port.uartclk = sci_port->clk_rates[SCI_FCK];
}
static void sci_port_disable(struct sci_port *sci_port)
{
unsigned int i;
if (!sci_port->port.dev)
return;
/* Cancel the break timer to ensure that the timer handler will not try
* to access the hardware with clocks and power disabled. Reset the
* break flag to make the break debouncing state machine ready for the
* next break.
*/
del_timer_sync(&sci_port->break_timer);
sci_port->break_flag = 0;
for (i = SCI_NUM_CLKS; i-- > 0; )
clk_disable_unprepare(sci_port->clks[i]);
pm_runtime_put_sync(sci_port->port.dev);
}
static inline unsigned long port_rx_irq_mask(struct uart_port *port)
{
/*
* Not all ports (such as SCIFA) will support REIE. Rather than
* special-casing the port type, we check the port initialization
* IRQ enable mask to see whether the IRQ is desired at all. If
* it's unset, it's logically inferred that there's no point in
* testing for it.
*/
return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE);
}
static void sci_start_tx(struct uart_port *port)
{
struct sci_port *s = to_sci_port(port);
unsigned short ctrl;
#ifdef CONFIG_SERIAL_SH_SCI_DMA
if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
u16 new, scr = serial_port_in(port, SCSCR);
if (s->chan_tx)
new = scr | SCSCR_TDRQE;
else
new = scr & ~SCSCR_TDRQE;
if (new != scr)
serial_port_out(port, SCSCR, new);
}
if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
dma_submit_error(s->cookie_tx)) {
s->cookie_tx = 0;
schedule_work(&s->work_tx);
}
#endif
if (!s->chan_tx || port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
/* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
ctrl = serial_port_in(port, SCSCR);
serial_port_out(port, SCSCR, ctrl | SCSCR_TIE);
}
}
static void sci_stop_tx(struct uart_port *port)
{
unsigned short ctrl;
/* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
ctrl = serial_port_in(port, SCSCR);
if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
ctrl &= ~SCSCR_TDRQE;
ctrl &= ~SCSCR_TIE;
serial_port_out(port, SCSCR, ctrl);
}
static void sci_start_rx(struct uart_port *port)
{
unsigned short ctrl;
ctrl = serial_port_in(port, SCSCR) | port_rx_irq_mask(port);
if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
ctrl &= ~SCSCR_RDRQE;
serial_port_out(port, SCSCR, ctrl);
}
static void sci_stop_rx(struct uart_port *port)
{
unsigned short ctrl;
ctrl = serial_port_in(port, SCSCR);
if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
ctrl &= ~SCSCR_RDRQE;
ctrl &= ~port_rx_irq_mask(port);
serial_port_out(port, SCSCR, ctrl);
}
static void sci_clear_SCxSR(struct uart_port *port, unsigned int mask)
{
if (port->type == PORT_SCI) {
/* Just store the mask */
serial_port_out(port, SCxSR, mask);
} else if (to_sci_port(port)->overrun_mask == SCIFA_ORER) {
/* SCIFA/SCIFB and SCIF on SH7705/SH7720/SH7721 */
/* Only clear the status bits we want to clear */
serial_port_out(port, SCxSR,
serial_port_in(port, SCxSR) & mask);
} else {
/* Store the mask, clear parity/framing errors */
serial_port_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC));
}
}
#if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
#ifdef CONFIG_CONSOLE_POLL
static int sci_poll_get_char(struct uart_port *port)
{
unsigned short status;
int c;
do {
status = serial_port_in(port, SCxSR);
if (status & SCxSR_ERRORS(port)) {
sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
continue;
}
break;
} while (1);
if (!(status & SCxSR_RDxF(port)))
return NO_POLL_CHAR;
c = serial_port_in(port, SCxRDR);
/* Dummy read */
serial_port_in(port, SCxSR);
sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
return c;
}
#endif
static void sci_poll_put_char(struct uart_port *port, unsigned char c)
{
unsigned short status;
do {
status = serial_port_in(port, SCxSR);
} while (!(status & SCxSR_TDxE(port)));
serial_port_out(port, SCxTDR, c);
sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
}
#endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE */
static void sci_init_pins(struct uart_port *port, unsigned int cflag)
{
struct sci_port *s = to_sci_port(port);
const struct plat_sci_reg *reg = sci_regmap[s->cfg->regtype] + SCSPTR;
/*
* Use port-specific handler if provided.
*/
if (s->cfg->ops && s->cfg->ops->init_pins) {
s->cfg->ops->init_pins(port, cflag);
return;
}
/*
* For the generic path SCSPTR is necessary. Bail out if that's
* unavailable, too.
*/
if (!reg->size)
return;
if ((s->cfg->capabilities & SCIx_HAVE_RTSCTS) &&
((!(cflag & CRTSCTS)))) {
unsigned short status;
status = serial_port_in(port, SCSPTR);
status &= ~SCSPTR_CTSIO;
status |= SCSPTR_RTSIO;
serial_port_out(port, SCSPTR, status); /* Set RTS = 1 */
}
}
static int sci_txfill(struct uart_port *port)
{
const struct plat_sci_reg *reg;
reg = sci_getreg(port, SCTFDR);
if (reg->size)
return serial_port_in(port, SCTFDR) & ((port->fifosize << 1) - 1);
reg = sci_getreg(port, SCFDR);
if (reg->size)
return serial_port_in(port, SCFDR) >> 8;
return !(serial_port_in(port, SCxSR) & SCI_TDRE);
}
static int sci_txroom(struct uart_port *port)
{
return port->fifosize - sci_txfill(port);
}
static int sci_rxfill(struct uart_port *port)
{
const struct plat_sci_reg *reg;
reg = sci_getreg(port, SCRFDR);
if (reg->size)
return serial_port_in(port, SCRFDR) & ((port->fifosize << 1) - 1);
reg = sci_getreg(port, SCFDR);
if (reg->size)
return serial_port_in(port, SCFDR) & ((port->fifosize << 1) - 1);
return (serial_port_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
}
/*
* SCI helper for checking the state of the muxed port/RXD pins.
*/
static inline int sci_rxd_in(struct uart_port *port)
{
struct sci_port *s = to_sci_port(port);
if (s->cfg->port_reg <= 0)
return 1;
/* Cast for ARM damage */
return !!__raw_readb((void __iomem *)(uintptr_t)s->cfg->port_reg);
}
/* ********************************************************************** *
* the interrupt related routines *
* ********************************************************************** */
static void sci_transmit_chars(struct uart_port *port)
{
struct circ_buf *xmit = &port->state->xmit;
unsigned int stopped = uart_tx_stopped(port);
unsigned short status;
unsigned short ctrl;
int count;
status = serial_port_in(port, SCxSR);
if (!(status & SCxSR_TDxE(port))) {
ctrl = serial_port_in(port, SCSCR);
if (uart_circ_empty(xmit))
ctrl &= ~SCSCR_TIE;
else
ctrl |= SCSCR_TIE;
serial_port_out(port, SCSCR, ctrl);
return;
}
count = sci_txroom(port);
do {
unsigned char c;
if (port->x_char) {
c = port->x_char;
port->x_char = 0;
} else if (!uart_circ_empty(xmit) && !stopped) {
c = xmit->buf[xmit->tail];
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
} else {
break;
}
serial_port_out(port, SCxTDR, c);
port->icount.tx++;
} while (--count > 0);
sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
if (uart_circ_empty(xmit)) {
sci_stop_tx(port);
} else {
ctrl = serial_port_in(port, SCSCR);
if (port->type != PORT_SCI) {
serial_port_in(port, SCxSR); /* Dummy read */
sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
}
ctrl |= SCSCR_TIE;
serial_port_out(port, SCSCR, ctrl);
}
}
/* On SH3, SCIF may read end-of-break as a space->mark char */
#define STEPFN(c) ({int __c = (c); (((__c-1)|(__c)) == -1); })
static void sci_receive_chars(struct uart_port *port)
{
struct sci_port *sci_port = to_sci_port(port);
struct tty_port *tport = &port->state->port;
int i, count, copied = 0;
unsigned short status;
unsigned char flag;
status = serial_port_in(port, SCxSR);
if (!(status & SCxSR_RDxF(port)))
return;
while (1) {
/* Don't copy more bytes than there is room for in the buffer */
count = tty_buffer_request_room(tport, sci_rxfill(port));
/* If for any reason we can't copy more data, we're done! */
if (count == 0)
break;
if (port->type == PORT_SCI) {
char c = serial_port_in(port, SCxRDR);
if (uart_handle_sysrq_char(port, c) ||
sci_port->break_flag)
count = 0;
else
tty_insert_flip_char(tport, c, TTY_NORMAL);
} else {
for (i = 0; i < count; i++) {
char c = serial_port_in(port, SCxRDR);
status = serial_port_in(port, SCxSR);
#if defined(CONFIG_CPU_SH3)
/* Skip "chars" during break */
if (sci_port->break_flag) {
if ((c == 0) &&
(status & SCxSR_FER(port))) {
count--; i--;
continue;
}
/* Nonzero => end-of-break */
dev_dbg(port->dev, "debounce<%02x>\n", c);
sci_port->break_flag = 0;
if (STEPFN(c)) {
count--; i--;
continue;
}
}
#endif /* CONFIG_CPU_SH3 */
if (uart_handle_sysrq_char(port, c)) {
count--; i--;
continue;
}
/* Store data and status */
if (status & SCxSR_FER(port)) {
flag = TTY_FRAME;
port->icount.frame++;
dev_notice(port->dev, "frame error\n");
} else if (status & SCxSR_PER(port)) {
flag = TTY_PARITY;
port->icount.parity++;
dev_notice(port->dev, "parity error\n");
} else
flag = TTY_NORMAL;
tty_insert_flip_char(tport, c, flag);
}
}
serial_port_in(port, SCxSR); /* dummy read */
sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
copied += count;
port->icount.rx += count;
}
if (copied) {
/* Tell the rest of the system the news. New characters! */
tty_flip_buffer_push(tport);
} else {
serial_port_in(port, SCxSR); /* dummy read */
sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
}
}
#define SCI_BREAK_JIFFIES (HZ/20)
/*
* The sci generates interrupts during the break,
* 1 per millisecond or so during the break period, for 9600 baud.
* So dont bother disabling interrupts.
* But dont want more than 1 break event.
* Use a kernel timer to periodically poll the rx line until
* the break is finished.
*/
static inline void sci_schedule_break_timer(struct sci_port *port)
{
mod_timer(&port->break_timer, jiffies + SCI_BREAK_JIFFIES);
}
/* Ensure that two consecutive samples find the break over. */
static void sci_break_timer(unsigned long data)
{
struct sci_port *port = (struct sci_port *)data;
if (sci_rxd_in(&port->port) == 0) {
port->break_flag = 1;
sci_schedule_break_timer(port);
} else if (port->break_flag == 1) {
/* break is over. */
port->break_flag = 2;
sci_schedule_break_timer(port);
} else
port->break_flag = 0;
}
static int sci_handle_errors(struct uart_port *port)
{
int copied = 0;
unsigned short status = serial_port_in(port, SCxSR);
struct tty_port *tport = &port->state->port;
struct sci_port *s = to_sci_port(port);
/* Handle overruns */
if (status & s->overrun_mask) {
port->icount.overrun++;
/* overrun error */
if (tty_insert_flip_char(tport, 0, TTY_OVERRUN))
copied++;
dev_notice(port->dev, "overrun error\n");
}
if (status & SCxSR_FER(port)) {
if (sci_rxd_in(port) == 0) {
/* Notify of BREAK */
struct sci_port *sci_port = to_sci_port(port);
if (!sci_port->break_flag) {
port->icount.brk++;
sci_port->break_flag = 1;
sci_schedule_break_timer(sci_port);
/* Do sysrq handling. */
if (uart_handle_break(port))
return 0;
dev_dbg(port->dev, "BREAK detected\n");
if (tty_insert_flip_char(tport, 0, TTY_BREAK))
copied++;
}
} else {
/* frame error */
port->icount.frame++;
if (tty_insert_flip_char(tport, 0, TTY_FRAME))
copied++;
dev_notice(port->dev, "frame error\n");
}
}
if (status & SCxSR_PER(port)) {
/* parity error */
port->icount.parity++;
if (tty_insert_flip_char(tport, 0, TTY_PARITY))
copied++;
dev_notice(port->dev, "parity error\n");
}
if (copied)
tty_flip_buffer_push(tport);
return copied;
}
static int sci_handle_fifo_overrun(struct uart_port *port)
{
struct tty_port *tport = &port->state->port;
struct sci_port *s = to_sci_port(port);
const struct plat_sci_reg *reg;
int copied = 0;
u16 status;
reg = sci_getreg(port, s->overrun_reg);
if (!reg->size)
return 0;
status = serial_port_in(port, s->overrun_reg);
if (status & s->overrun_mask) {
status &= ~s->overrun_mask;
serial_port_out(port, s->overrun_reg, status);
port->icount.overrun++;
tty_insert_flip_char(tport, 0, TTY_OVERRUN);
tty_flip_buffer_push(tport);
dev_dbg(port->dev, "overrun error\n");
copied++;
}
return copied;
}
static int sci_handle_breaks(struct uart_port *port)
{
int copied = 0;
unsigned short status = serial_port_in(port, SCxSR);
struct tty_port *tport = &port->state->port;
struct sci_port *s = to_sci_port(port);
if (uart_handle_break(port))
return 0;
if (!s->break_flag && status & SCxSR_BRK(port)) {
#if defined(CONFIG_CPU_SH3)
/* Debounce break */
s->break_flag = 1;
#endif
port->icount.brk++;
/* Notify of BREAK */
if (tty_insert_flip_char(tport, 0, TTY_BREAK))
copied++;
dev_dbg(port->dev, "BREAK detected\n");
}
if (copied)
tty_flip_buffer_push(tport);
copied += sci_handle_fifo_overrun(port);
return copied;
}
#ifdef CONFIG_SERIAL_SH_SCI_DMA
static void sci_dma_tx_complete(void *arg)
{
struct sci_port *s = arg;
struct uart_port *port = &s->port;
struct circ_buf *xmit = &port->state->xmit;
unsigned long flags;
dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
spin_lock_irqsave(&port->lock, flags);
xmit->tail += s->tx_dma_len;
xmit->tail &= UART_XMIT_SIZE - 1;
port->icount.tx += s->tx_dma_len;
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
if (!uart_circ_empty(xmit)) {
s->cookie_tx = 0;
schedule_work(&s->work_tx);
} else {
s->cookie_tx = -EINVAL;
if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
u16 ctrl = serial_port_in(port, SCSCR);
serial_port_out(port, SCSCR, ctrl & ~SCSCR_TIE);
}
}
spin_unlock_irqrestore(&port->lock, flags);
}
/* Locking: called with port lock held */
static int sci_dma_rx_push(struct sci_port *s, void *buf, size_t count)
{
struct uart_port *port = &s->port;
struct tty_port *tport = &port->state->port;
int copied;
copied = tty_insert_flip_string(tport, buf, count);
if (copied < count) {
dev_warn(port->dev, "Rx overrun: dropping %zu bytes\n",
count - copied);
port->icount.buf_overrun++;
}
port->icount.rx += copied;
return copied;
}
static int sci_dma_rx_find_active(struct sci_port *s)
{
unsigned int i;
for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
if (s->active_rx == s->cookie_rx[i])
return i;
dev_err(s->port.dev, "%s: Rx cookie %d not found!\n", __func__,
s->active_rx);
return -1;
}
static void sci_rx_dma_release(struct sci_port *s, bool enable_pio)
{
struct dma_chan *chan = s->chan_rx;
struct uart_port *port = &s->port;
unsigned long flags;
spin_lock_irqsave(&port->lock, flags);
s->chan_rx = NULL;
s->cookie_rx[0] = s->cookie_rx[1] = -EINVAL;
spin_unlock_irqrestore(&port->lock, flags);
dmaengine_terminate_all(chan);
dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0],
sg_dma_address(&s->sg_rx[0]));
dma_release_channel(chan);
if (enable_pio)
sci_start_rx(port);
}
static void sci_dma_rx_complete(void *arg)
{
struct sci_port *s = arg;
struct dma_chan *chan = s->chan_rx;
struct uart_port *port = &s->port;
struct dma_async_tx_descriptor *desc;
unsigned long flags;
int active, count = 0;
dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line,
s->active_rx);
spin_lock_irqsave(&port->lock, flags);
active = sci_dma_rx_find_active(s);
if (active >= 0)
count = sci_dma_rx_push(s, s->rx_buf[active], s->buf_len_rx);
mod_timer(&s->rx_timer, jiffies + s->rx_timeout);
if (count)
tty_flip_buffer_push(&port->state->port);
desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[active], 1,
DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc)
goto fail;
desc->callback = sci_dma_rx_complete;
desc->callback_param = s;
s->cookie_rx[active] = dmaengine_submit(desc);
if (dma_submit_error(s->cookie_rx[active]))
goto fail;
s->active_rx = s->cookie_rx[!active];
dma_async_issue_pending(chan);
dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",
__func__, s->cookie_rx[active], active, s->active_rx);
spin_unlock_irqrestore(&port->lock, flags);
return;
fail:
spin_unlock_irqrestore(&port->lock, flags);
dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
sci_rx_dma_release(s, true);
}
static void sci_tx_dma_release(struct sci_port *s, bool enable_pio)
{
struct dma_chan *chan = s->chan_tx;
struct uart_port *port = &s->port;
unsigned long flags;
spin_lock_irqsave(&port->lock, flags);
s->chan_tx = NULL;
s->cookie_tx = -EINVAL;
spin_unlock_irqrestore(&port->lock, flags);
dmaengine_terminate_all(chan);
dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE,
DMA_TO_DEVICE);
dma_release_channel(chan);
if (enable_pio)
sci_start_tx(port);
}
static void sci_submit_rx(struct sci_port *s)
{
struct dma_chan *chan = s->chan_rx;
int i;
for (i = 0; i < 2; i++) {
struct scatterlist *sg = &s->sg_rx[i];
struct dma_async_tx_descriptor *desc;
desc = dmaengine_prep_slave_sg(chan,
sg, 1, DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc)
goto fail;
desc->callback = sci_dma_rx_complete;
desc->callback_param = s;
s->cookie_rx[i] = dmaengine_submit(desc);
if (dma_submit_error(s->cookie_rx[i]))
goto fail;
dev_dbg(s->port.dev, "%s(): cookie %d to #%d\n", __func__,
s->cookie_rx[i], i);
}
s->active_rx = s->cookie_rx[0];
dma_async_issue_pending(chan);
return;
fail:
if (i)
dmaengine_terminate_all(chan);
for (i = 0; i < 2; i++)
s->cookie_rx[i] = -EINVAL;
s->active_rx = -EINVAL;
dev_warn(s->port.dev, "Failed to re-start Rx DMA, using PIO\n");
sci_rx_dma_release(s, true);
}
static void work_fn_tx(struct work_struct *work)
{
struct sci_port *s = container_of(work, struct sci_port, work_tx);
struct dma_async_tx_descriptor *desc;
struct dma_chan *chan = s->chan_tx;
struct uart_port *port = &s->port;
struct circ_buf *xmit = &port->state->xmit;
dma_addr_t buf;
/*
* DMA is idle now.
* Port xmit buffer is already mapped, and it is one page... Just adjust
* offsets and lengths. Since it is a circular buffer, we have to
* transmit till the end, and then the rest. Take the port lock to get a
* consistent xmit buffer state.
*/
spin_lock_irq(&port->lock);
buf = s->tx_dma_addr + (xmit->tail & (UART_XMIT_SIZE - 1));
s->tx_dma_len = min_t(unsigned int,
CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE),
CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE));
spin_unlock_irq(&port->lock);
desc = dmaengine_prep_slave_single(chan, buf, s->tx_dma_len,
DMA_MEM_TO_DEV,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc) {
dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n");
/* switch to PIO */
sci_tx_dma_release(s, true);
return;
}
dma_sync_single_for_device(chan->device->dev, buf, s->tx_dma_len,
DMA_TO_DEVICE);
spin_lock_irq(&port->lock);
desc->callback = sci_dma_tx_complete;
desc->callback_param = s;
spin_unlock_irq(&port->lock);
s->cookie_tx = dmaengine_submit(desc);
if (dma_submit_error(s->cookie_tx)) {
dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
/* switch to PIO */
sci_tx_dma_release(s, true);
return;
}
dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n",
__func__, xmit->buf, xmit->tail, xmit->head, s->cookie_tx);
dma_async_issue_pending(chan);
}
static void rx_timer_fn(unsigned long arg)
{
struct sci_port *s = (struct sci_port *)arg;
struct dma_chan *chan = s->chan_rx;
struct uart_port *port = &s->port;
struct dma_tx_state state;
enum dma_status status;
unsigned long flags;
unsigned int read;
int active, count;
u16 scr;
spin_lock_irqsave(&port->lock, flags);
dev_dbg(port->dev, "DMA Rx timed out\n");
active = sci_dma_rx_find_active(s);
if (active < 0) {
spin_unlock_irqrestore(&port->lock, flags);
return;
}
status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
if (status == DMA_COMPLETE) {
dev_dbg(port->dev, "Cookie %d #%d has already completed\n",
s->active_rx, active);
spin_unlock_irqrestore(&port->lock, flags);
/* Let packet complete handler take care of the packet */
return;
}
dmaengine_pause(chan);
/*
* sometimes DMA transfer doesn't stop even if it is stopped and
* data keeps on coming until transaction is complete so check
* for DMA_COMPLETE again
* Let packet complete handler take care of the packet
*/
status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
if (status == DMA_COMPLETE) {
spin_unlock_irqrestore(&port->lock, flags);
dev_dbg(port->dev, "Transaction complete after DMA engine was stopped");
return;
}
/* Handle incomplete DMA receive */
dmaengine_terminate_all(s->chan_rx);
read = sg_dma_len(&s->sg_rx[active]) - state.residue;
dev_dbg(port->dev, "Read %u bytes with cookie %d\n", read,
s->active_rx);
if (read) {
count = sci_dma_rx_push(s, s->rx_buf[active], read);
if (count)
tty_flip_buffer_push(&port->state->port);
}
if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
sci_submit_rx(s);
/* Direct new serial port interrupts back to CPU */
scr = serial_port_in(port, SCSCR);
if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
scr &= ~SCSCR_RDRQE;
enable_irq(s->irqs[SCIx_RXI_IRQ]);
}
serial_port_out(port, SCSCR, scr | SCSCR_RIE);
spin_unlock_irqrestore(&port->lock, flags);
}
static struct dma_chan *sci_request_dma_chan(struct uart_port *port,
enum dma_transfer_direction dir,
unsigned int id)
{
dma_cap_mask_t mask;
struct dma_chan *chan;
struct dma_slave_config cfg;
int ret;
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);
chan = dma_request_slave_channel_compat(mask, shdma_chan_filter,
(void *)(unsigned long)id, port->dev,
dir == DMA_MEM_TO_DEV ? "tx" : "rx");
if (!chan) {
dev_warn(port->dev,
"dma_request_slave_channel_compat failed\n");
return NULL;
}
memset(&cfg, 0, sizeof(cfg));
cfg.direction = dir;
if (dir == DMA_MEM_TO_DEV) {
cfg.dst_addr = port->mapbase +
(sci_getreg(port, SCxTDR)->offset << port->regshift);
cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
} else {
cfg.src_addr = port->mapbase +
(sci_getreg(port, SCxRDR)->offset << port->regshift);
cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
}
ret = dmaengine_slave_config(chan, &cfg);
if (ret) {
dev_warn(port->dev, "dmaengine_slave_config failed %d\n", ret);
dma_release_channel(chan);
return NULL;
}
return chan;
}
static void sci_request_dma(struct uart_port *port)
{
struct sci_port *s = to_sci_port(port);
struct dma_chan *chan;
dev_dbg(port->dev, "%s: port %d\n", __func__, port->line);
if (!port->dev->of_node &&
(s->cfg->dma_slave_tx <= 0 || s->cfg->dma_slave_rx <= 0))
return;
s->cookie_tx = -EINVAL;
chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV, s->cfg->dma_slave_tx);
dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
if (chan) {
s->chan_tx = chan;
/* UART circular tx buffer is an aligned page. */
s->tx_dma_addr = dma_map_single(chan->device->dev,
port->state->xmit.buf,
UART_XMIT_SIZE,
DMA_TO_DEVICE);
if (dma_mapping_error(chan->device->dev, s->tx_dma_addr)) {
dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n");
dma_release_channel(chan);
s->chan_tx = NULL;
} else {
dev_dbg(port->dev, "%s: mapped %lu@%p to %pad\n",
__func__, UART_XMIT_SIZE,
port->state->xmit.buf, &s->tx_dma_addr);
}
INIT_WORK(&s->work_tx, work_fn_tx);
}
chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM, s->cfg->dma_slave_rx);
dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
if (chan) {
unsigned int i;
dma_addr_t dma;
void *buf;
s->chan_rx = chan;
s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize);
buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2,
&dma, GFP_KERNEL);
if (!buf) {
dev_warn(port->dev,
"Failed to allocate Rx dma buffer, using PIO\n");
dma_release_channel(chan);
s->chan_rx = NULL;
return;
}
for (i = 0; i < 2; i++) {
struct scatterlist *sg = &s->sg_rx[i];
sg_init_table(sg, 1);
s->rx_buf[i] = buf;
sg_dma_address(sg) = dma;
sg_dma_len(sg) = s->buf_len_rx;
buf += s->buf_len_rx;
dma += s->buf_len_rx;
}
setup_timer(&s->rx_timer, rx_timer_fn, (unsigned long)s);
if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
sci_submit_rx(s);
}
}
static void sci_free_dma(struct uart_port *port)
{
struct sci_port *s = to_sci_port(port);
if (s->chan_tx)
sci_tx_dma_release(s, false);
if (s->chan_rx)
sci_rx_dma_release(s, false);
}
#else
static inline void sci_request_dma(struct uart_port *port)
{
}
static inline void sci_free_dma(struct uart_port *port)
{
}
#endif
static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
{
#ifdef CONFIG_SERIAL_SH_SCI_DMA
struct uart_port *port = ptr;
struct sci_port *s = to_sci_port(port);
if (s->chan_rx) {
u16 scr = serial_port_in(port, SCSCR);
u16 ssr = serial_port_in(port, SCxSR);
/* Disable future Rx interrupts */
if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
disable_irq_nosync(irq);
scr |= SCSCR_RDRQE;
} else {
scr &= ~SCSCR_RIE;
sci_submit_rx(s);
}
serial_port_out(port, SCSCR, scr);
/* Clear current interrupt */
serial_port_out(port, SCxSR,
ssr & ~(SCIF_DR | SCxSR_RDxF(port)));
dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u jiffies\n",
jiffies, s->rx_timeout);
mod_timer(&s->rx_timer, jiffies + s->rx_timeout);
return IRQ_HANDLED;
}
#endif
/* I think sci_receive_chars has to be called irrespective
* of whether the I_IXOFF is set, otherwise, how is the interrupt
* to be disabled?
*/
sci_receive_chars(ptr);
return IRQ_HANDLED;
}
static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
{
struct uart_port *port = ptr;
unsigned long flags;
spin_lock_irqsave(&port->lock, flags);
sci_transmit_chars(port);
spin_unlock_irqrestore(&port->lock, flags);
return IRQ_HANDLED;
}
static irqreturn_t sci_er_interrupt(int irq, void *ptr)
{
struct uart_port *port = ptr;
struct sci_port *s = to_sci_port(port);
/* Handle errors */
if (port->type == PORT_SCI) {
if (sci_handle_errors(port)) {
/* discard character in rx buffer */
serial_port_in(port, SCxSR);
sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
}
} else {
sci_handle_fifo_overrun(port);
if (!s->chan_rx)
sci_receive_chars(ptr);
}
sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
/* Kick the transmission */
if (!s->chan_tx)
sci_tx_interrupt(irq, ptr);
return IRQ_HANDLED;
}
static irqreturn_t sci_br_interrupt(int irq, void *ptr)
{
struct uart_port *port = ptr;
/* Handle BREAKs */
sci_handle_breaks(port);
sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port));
return IRQ_HANDLED;
}
static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
{
unsigned short ssr_status, scr_status, err_enabled, orer_status = 0;
struct uart_port *port = ptr;
struct sci_port *s = to_sci_port(port);
irqreturn_t ret = IRQ_NONE;
ssr_status = serial_port_in(port, SCxSR);
scr_status = serial_port_in(port, SCSCR);
if (s->overrun_reg == SCxSR)
orer_status = ssr_status;
else {
if (sci_getreg(port, s->overrun_reg)->size)
orer_status = serial_port_in(port, s->overrun_reg);
}
err_enabled = scr_status & port_rx_irq_mask(port);
/* Tx Interrupt */
if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
!s->chan_tx)
ret = sci_tx_interrupt(irq, ptr);
/*
* Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
* DR flags
*/
if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
(scr_status & SCSCR_RIE))
ret = sci_rx_interrupt(irq, ptr);
/* Error Interrupt */
if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
ret = sci_er_interrupt(irq, ptr);
/* Break Interrupt */
if ((ssr_status & SCxSR_BRK(port)) && err_enabled)
ret = sci_br_interrupt(irq, ptr);
/* Overrun Interrupt */
if (orer_status & s->overrun_mask) {
sci_handle_fifo_overrun(port);
ret = IRQ_HANDLED;
}
return ret;
}
static const struct sci_irq_desc {
const char *desc;
irq_handler_t handler;
} sci_irq_desc[] = {
/*
* Split out handlers, the default case.
*/
[SCIx_ERI_IRQ] = {
.desc = "rx err",
.handler = sci_er_interrupt,
},
[SCIx_RXI_IRQ] = {
.desc = "rx full",
.handler = sci_rx_interrupt,
},
[SCIx_TXI_IRQ] = {
.desc = "tx empty",
.handler = sci_tx_interrupt,
},
[SCIx_BRI_IRQ] = {
.desc = "break",
.handler = sci_br_interrupt,
},
/*
* Special muxed handler.
*/
[SCIx_MUX_IRQ] = {
.desc = "mux",
.handler = sci_mpxed_interrupt,
},
};
static int sci_request_irq(struct sci_port *port)
{
struct uart_port *up = &port->port;
int i, j, ret = 0;
for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
const struct sci_irq_desc *desc;
int irq;
if (SCIx_IRQ_IS_MUXED(port)) {
i = SCIx_MUX_IRQ;
irq = up->irq;
} else {
irq = port->irqs[i];
/*
* Certain port types won't support all of the
* available interrupt sources.
*/
if (unlikely(irq < 0))
continue;
}
desc = sci_irq_desc + i;
port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
dev_name(up->dev), desc->desc);
if (!port->irqstr[j])
goto out_nomem;
ret = request_irq(irq, desc->handler, up->irqflags,
port->irqstr[j], port);
if (unlikely(ret)) {
dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc);
goto out_noirq;
}
}
return 0;
out_noirq:
while (--i >= 0)
free_irq(port->irqs[i], port);
out_nomem:
while (--j >= 0)
kfree(port->irqstr[j]);
return ret;
}
static void sci_free_irq(struct sci_port *port)
{
int i;
/*
* Intentionally in reverse order so we iterate over the muxed
* IRQ first.
*/
for (i = 0; i < SCIx_NR_IRQS; i++) {
int irq = port->irqs[i];
/*
* Certain port types won't support all of the available
* interrupt sources.
*/
if (unlikely(irq < 0))
continue;
free_irq(port->irqs[i], port);
kfree(port->irqstr[i]);
if (SCIx_IRQ_IS_MUXED(port)) {
/* If there's only one IRQ, we're done. */
return;
}
}
}
static unsigned int sci_tx_empty(struct uart_port *port)
{
unsigned short status = serial_port_in(port, SCxSR);
unsigned short in_tx_fifo = sci_txfill(port);
return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
}
/*
* Modem control is a bit of a mixed bag for SCI(F) ports. Generally
* CTS/RTS is supported in hardware by at least one port and controlled
* via SCSPTR (SCxPCR for SCIFA/B parts), or external pins (presently
* handled via the ->init_pins() op, which is a bit of a one-way street,
* lacking any ability to defer pin control -- this will later be
* converted over to the GPIO framework).
*
* Other modes (such as loopback) are supported generically on certain
* port types, but not others. For these it's sufficient to test for the
* existence of the support register and simply ignore the port type.
*/
static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
if (mctrl & TIOCM_LOOP) {
const struct plat_sci_reg *reg;
/*
* Standard loopback mode for SCFCR ports.
*/
reg = sci_getreg(port, SCFCR);
if (reg->size)
serial_port_out(port, SCFCR,
serial_port_in(port, SCFCR) |
SCFCR_LOOP);
}
}
static unsigned int sci_get_mctrl(struct uart_port *port)
{
/*
* CTS/RTS is handled in hardware when supported, while nothing
* else is wired up. Keep it simple and simply assert DSR/CAR.
*/
return TIOCM_DSR | TIOCM_CAR;
}
static void sci_break_ctl(struct uart_port *port, int break_state)
{
struct sci_port *s = to_sci_port(port);
const struct plat_sci_reg *reg = sci_regmap[s->cfg->regtype] + SCSPTR;
unsigned short scscr, scsptr;
/* check wheter the port has SCSPTR */
if (!reg->size) {
/*
* Not supported by hardware. Most parts couple break and rx
* interrupts together, with break detection always enabled.
*/
return;
}
scsptr = serial_port_in(port, SCSPTR);
scscr = serial_port_in(port, SCSCR);
if (break_state == -1) {
scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT;
scscr &= ~SCSCR_TE;
} else {
scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO;
scscr |= SCSCR_TE;
}
serial_port_out(port, SCSPTR, scsptr);
serial_port_out(port, SCSCR, scscr);
}
static int sci_startup(struct uart_port *port)
{
struct sci_port *s = to_sci_port(port);
unsigned long flags;
int ret;
dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
ret = sci_request_irq(s);
if (unlikely(ret < 0))
return ret;
sci_request_dma(port);
spin_lock_irqsave(&port->lock, flags);
sci_start_tx(port);
sci_start_rx(port);
spin_unlock_irqrestore(&port->lock, flags);
return 0;
}
static void sci_shutdown(struct uart_port *port)
{
struct sci_port *s = to_sci_port(port);
unsigned long flags;
dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
spin_lock_irqsave(&port->lock, flags);
sci_stop_rx(port);
sci_stop_tx(port);
spin_unlock_irqrestore(&port->lock, flags);
#ifdef CONFIG_SERIAL_SH_SCI_DMA
if (s->chan_rx) {
dev_dbg(port->dev, "%s(%d) deleting rx_timer\n", __func__,
port->line);
del_timer_sync(&s->rx_timer);
}
#endif
sci_free_dma(port);
sci_free_irq(s);
}
static int sci_sck_calc(struct sci_port *s, unsigned int bps,
unsigned int *srr)
{
unsigned long freq = s->clk_rates[SCI_SCK];
unsigned int min_sr, max_sr, sr;
int err, min_err = INT_MAX;
if (s->sampling_rate) {
/* SCI(F) has a fixed sampling rate */
min_sr = max_sr = s->sampling_rate / 2;
} else {
/* HSCIF has a variable 1/(8..32) sampling rate */
min_sr = 8;
max_sr = 32;
}
for (sr = max_sr; sr >= min_sr; sr--) {
err = DIV_ROUND_CLOSEST(freq, sr) - bps;
if (abs(err) >= abs(min_err))
continue;
min_err = err;
*srr = sr - 1;
if (!err)
break;
}
dev_dbg(s->port.dev, "SCK: %u%+d bps using SR %u\n", bps, min_err,
*srr + 1);
return min_err;
}
static int sci_brg_calc(struct sci_port *s, unsigned int bps,
unsigned long freq, unsigned int *dlr,
unsigned int *srr)
{
unsigned int min_sr, max_sr, sr, dl;
int err, min_err = INT_MAX;
if (s->sampling_rate) {
/* SCIF has a fixed sampling rate */
min_sr = max_sr = s->sampling_rate / 2;
} else {
/* HSCIF has a variable 1/(8..32) sampling rate */
min_sr = 8;
max_sr = 32;
}
for (sr = max_sr; sr >= min_sr; sr--) {
dl = DIV_ROUND_CLOSEST(freq, sr * bps);
dl = clamp(dl, 1U, 65535U);
err = DIV_ROUND_CLOSEST(freq, sr * dl) - bps;
if (abs(err) >= abs(min_err))
continue;
min_err = err;
*dlr = dl;
*srr = sr - 1;
if (!err)
break;
}
dev_dbg(s->port.dev, "BRG: %u%+d bps using DL %u SR %u\n", bps,
min_err, *dlr, *srr + 1);
return min_err;
}
/* calculate sample rate, BRR, and clock select */
static int sci_scbrr_calc(struct sci_port *s, unsigned int bps,
unsigned int *brr, unsigned int *srr,
unsigned int *cks)
{
unsigned int min_sr, max_sr, shift, sr, br, prediv, scrate, c;
unsigned long freq = s->clk_rates[SCI_FCK];
int err, min_err = INT_MAX;
if (s->sampling_rate) {
min_sr = max_sr = s->sampling_rate;
shift = 0;
} else {
/* HSCIF has a variable sample rate */
min_sr = 8;
max_sr = 32;
shift = 1;
}
/*
* Find the combination of sample rate and clock select with the
* smallest deviation from the desired baud rate.
* Prefer high sample rates to maximise the receive margin.
*
* M: Receive margin (%)
* N: Ratio of bit rate to clock (N = sampling rate)
* D: Clock duty (D = 0 to 1.0)
* L: Frame length (L = 9 to 12)
* F: Absolute value of clock frequency deviation
*
* M = |(0.5 - 1 / 2 * N) - ((L - 0.5) * F) -
* (|D - 0.5| / N * (1 + F))|
* NOTE: Usually, treat D for 0.5, F is 0 by this calculation.
*/
for (sr = max_sr; sr >= min_sr; sr--) {
for (c = 0; c <= 3; c++) {
/* integerized formulas from HSCIF documentation */
prediv = sr * (1 << (2 * c + shift));
/*
* We need to calculate:
*
* br = freq / (prediv * bps) clamped to [1..256]
* err = freq / (br * prediv) - bps
*
* Watch out for overflow when calculating the desired
* sampling clock rate!
*/
if (bps > UINT_MAX / prediv)
break;
scrate = prediv * bps;
br = DIV_ROUND_CLOSEST(freq, scrate);
br = clamp(br, 1U, 256U);
err = DIV_ROUND_CLOSEST(freq, br * prediv) - bps;
if (abs(err) >= abs(min_err))
continue;
min_err = err;
*brr = br - 1;
*srr = sr - 1;
*cks = c;
if (!err)
goto found;
}
}
found:
dev_dbg(s->port.dev, "BRR: %u%+d bps using N %u SR %u cks %u\n", bps,
min_err, *brr, *srr + 1, *cks);
return min_err;
}
static void sci_reset(struct uart_port *port)
{
const struct plat_sci_reg *reg;
unsigned int status;
do {
status = serial_port_in(port, SCxSR);
} while (!(status & SCxSR_TEND(port)));
serial_port_out(port, SCSCR, 0x00); /* TE=0, RE=0, CKE1=0 */
reg = sci_getreg(port, SCFCR);
if (reg->size)
serial_port_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
}
static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
struct ktermios *old)
{
unsigned int baud, smr_val = 0, scr_val = 0, i;
unsigned int brr = 255, cks = 0, srr = 15, dl = 0, sccks = 0;
unsigned int brr1 = 255, cks1 = 0, srr1 = 15, dl1 = 0;
struct sci_port *s = to_sci_port(port);
const struct plat_sci_reg *reg;
int min_err = INT_MAX, err;
unsigned long max_freq = 0;
int best_clk = -1;
if ((termios->c_cflag & CSIZE) == CS7)
smr_val |= SCSMR_CHR;
if (termios->c_cflag & PARENB)
smr_val |= SCSMR_PE;
if (termios->c_cflag & PARODD)
smr_val |= SCSMR_PE | SCSMR_ODD;
if (termios->c_cflag & CSTOPB)
smr_val |= SCSMR_STOP;
/*
* earlyprintk comes here early on with port->uartclk set to zero.
* the clock framework is not up and running at this point so here
* we assume that 115200 is the maximum baud rate. please note that
* the baud rate is not programmed during earlyprintk - it is assumed
* that the previous boot loader has enabled required clocks and
* setup the baud rate generator hardware for us already.
*/
if (!port->uartclk) {
baud = uart_get_baud_rate(port, termios, old, 0, 115200);
goto done;
}
for (i = 0; i < SCI_NUM_CLKS; i++)
max_freq = max(max_freq, s->clk_rates[i]);
baud = uart_get_baud_rate(port, termios, old, 0,
max_freq / max(s->sampling_rate, 8U));
if (!baud)
goto done;
/*
* There can be multiple sources for the sampling clock. Find the one
* that gives us the smallest deviation from the desired baud rate.
*/
/* Optional Undivided External Clock */
if (s->clk_rates[SCI_SCK] && port->type != PORT_SCIFA &&
port->type != PORT_SCIFB) {
err = sci_sck_calc(s, baud, &srr1);
if (abs(err) < abs(min_err)) {
best_clk = SCI_SCK;
scr_val = SCSCR_CKE1;
sccks = SCCKS_CKS;
min_err = err;
srr = srr1;
if (!err)
goto done;
}
}
/* Optional BRG Frequency Divided External Clock */
if (s->clk_rates[SCI_SCIF_CLK] && sci_getreg(port, SCDL)->size) {
err = sci_brg_calc(s, baud, s->clk_rates[SCI_SCIF_CLK], &dl1,
&srr1);
if (abs(err) < abs(min_err)) {
best_clk = SCI_SCIF_CLK;
scr_val = SCSCR_CKE1;
sccks = 0;
min_err = err;
dl = dl1;
srr = srr1;
if (!err)
goto done;
}
}
/* Optional BRG Frequency Divided Internal Clock */
if (s->clk_rates[SCI_BRG_INT] && sci_getreg(port, SCDL)->size) {
err = sci_brg_calc(s, baud, s->clk_rates[SCI_BRG_INT], &dl1,
&srr1);
if (abs(err) < abs(min_err)) {
best_clk = SCI_BRG_INT;
scr_val = SCSCR_CKE1;
sccks = SCCKS_XIN;
min_err = err;
dl = dl1;
srr = srr1;
if (!min_err)
goto done;
}
}
/* Divided Functional Clock using standard Bit Rate Register */
err = sci_scbrr_calc(s, baud, &brr1, &srr1, &cks1);
if (abs(err) < abs(min_err)) {
best_clk = SCI_FCK;
scr_val = 0;
min_err = err;
brr = brr1;
srr = srr1;
cks = cks1;
}
done:
if (best_clk >= 0)
dev_dbg(port->dev, "Using clk %pC for %u%+d bps\n",
s->clks[best_clk], baud, min_err);
sci_port_enable(s);
/*
* Program the optional External Baud Rate Generator (BRG) first.
* It controls the mux to select (H)SCK or frequency divided clock.
*/
if (best_clk >= 0 && sci_getreg(port, SCCKS)->size) {
serial_port_out(port, SCDL, dl);
serial_port_out(port, SCCKS, sccks);
}
sci_reset(port);
uart_update_timeout(port, termios->c_cflag, baud);
if (best_clk >= 0) {
smr_val |= cks;
dev_dbg(port->dev,
"SCR 0x%x SMR 0x%x BRR %u CKS 0x%x DL %u SRR %u\n",
scr_val, smr_val, brr, sccks, dl, srr);
serial_port_out(port, SCSCR, scr_val);
serial_port_out(port, SCSMR, smr_val);
serial_port_out(port, SCBRR, brr);
if (sci_getreg(port, HSSRR)->size)
serial_port_out(port, HSSRR, srr | HSCIF_SRE);
/* Wait one bit interval */
udelay((1000000 + (baud - 1)) / baud);
} else {
/* Don't touch the bit rate configuration */
scr_val = s->cfg->scscr & (SCSCR_CKE1 | SCSCR_CKE0);
smr_val |= serial_port_in(port, SCSMR) & SCSMR_CKS;
dev_dbg(port->dev, "SCR 0x%x SMR 0x%x\n", scr_val, smr_val);
serial_port_out(port, SCSCR, scr_val);
serial_port_out(port, SCSMR, smr_val);
}
sci_init_pins(port, termios->c_cflag);
reg = sci_getreg(port, SCFCR);
if (reg->size) {
unsigned short ctrl = serial_port_in(port, SCFCR);
if (s->cfg->capabilities & SCIx_HAVE_RTSCTS) {
if (termios->c_cflag & CRTSCTS)
ctrl |= SCFCR_MCE;
else
ctrl &= ~SCFCR_MCE;
}
/*
* As we've done a sci_reset() above, ensure we don't
* interfere with the FIFOs while toggling MCE. As the
* reset values could still be set, simply mask them out.
*/
ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST);
serial_port_out(port, SCFCR, ctrl);
}
scr_val |= s->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0);
dev_dbg(port->dev, "SCSCR 0x%x\n", scr_val);
serial_port_out(port, SCSCR, scr_val);
#ifdef CONFIG_SERIAL_SH_SCI_DMA
/*
* Calculate delay for 2 DMA buffers (4 FIFO).
* See serial_core.c::uart_update_timeout().
* With 10 bits (CS8), 250Hz, 115200 baud and 64 bytes FIFO, the above
* function calculates 1 jiffie for the data plus 5 jiffies for the
* "slop(e)." Then below we calculate 5 jiffies (20ms) for 2 DMA
* buffers (4 FIFO sizes), but when performing a faster transfer, the
* value obtained by this formula is too small. Therefore, if the value
* is smaller than 20ms, use 20ms as the timeout value for DMA.
*/
if (s->chan_rx) {
unsigned int bits;
/* byte size and parity */
switch (termios->c_cflag & CSIZE) {
case CS5:
bits = 7;
break;
case CS6:
bits = 8;
break;
case CS7:
bits = 9;
break;
default:
bits = 10;
break;
}
if (termios->c_cflag & CSTOPB)
bits++;
if (termios->c_cflag & PARENB)
bits++;
s->rx_timeout = DIV_ROUND_UP((s->buf_len_rx * 2 * bits * HZ) /
(baud / 10), 10);
dev_dbg(port->dev, "DMA Rx t-out %ums, tty t-out %u jiffies\n",
s->rx_timeout * 1000 / HZ, port->timeout);
if (s->rx_timeout < msecs_to_jiffies(20))
s->rx_timeout = msecs_to_jiffies(20);
}
#endif
if ((termios->c_cflag & CREAD) != 0)
sci_start_rx(port);
sci_port_disable(s);
}
static void sci_pm(struct uart_port *port, unsigned int state,
unsigned int oldstate)
{
struct sci_port *sci_port = to_sci_port(port);
switch (state) {
case UART_PM_STATE_OFF:
sci_port_disable(sci_port);
break;
default:
sci_port_enable(sci_port);
break;
}
}
static const char *sci_type(struct uart_port *port)
{
switch (port->type) {
case PORT_IRDA:
return "irda";
case PORT_SCI:
return "sci";
case PORT_SCIF:
return "scif";
case PORT_SCIFA:
return "scifa";
case PORT_SCIFB:
return "scifb";
case PORT_HSCIF:
return "hscif";
}
return NULL;
}
static int sci_remap_port(struct uart_port *port)
{
struct sci_port *sport = to_sci_port(port);
/*
* Nothing to do if there's already an established membase.
*/
if (port->membase)
return 0;
if (port->flags & UPF_IOREMAP) {
port->membase = ioremap_nocache(port->mapbase, sport->reg_size);
if (unlikely(!port->membase)) {
dev_err(port->dev, "can't remap port#%d\n", port->line);
return -ENXIO;
}
} else {
/*
* For the simple (and majority of) cases where we don't
* need to do any remapping, just cast the cookie
* directly.
*/
port->membase = (void __iomem *)(uintptr_t)port->mapbase;
}
return 0;
}
static void sci_release_port(struct uart_port *port)
{
struct sci_port *sport = to_sci_port(port);
if (port->flags & UPF_IOREMAP) {
iounmap(port->membase);
port->membase = NULL;
}
release_mem_region(port->mapbase, sport->reg_size);
}
static int sci_request_port(struct uart_port *port)
{
struct resource *res;
struct sci_port *sport = to_sci_port(port);
int ret;
res = request_mem_region(port->mapbase, sport->reg_size,
dev_name(port->dev));
if (unlikely(res == NULL)) {
dev_err(port->dev, "request_mem_region failed.");
return -EBUSY;
}
ret = sci_remap_port(port);
if (unlikely(ret != 0)) {
release_resource(res);
return ret;
}
return 0;
}
static void sci_config_port(struct uart_port *port, int flags)
{
if (flags & UART_CONFIG_TYPE) {
struct sci_port *sport = to_sci_port(port);
port->type = sport->cfg->type;
sci_request_port(port);
}
}
static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
{
if (ser->baud_base < 2400)
/* No paper tape reader for Mitch.. */
return -EINVAL;
return 0;
}
static struct uart_ops sci_uart_ops = {
.tx_empty = sci_tx_empty,
.set_mctrl = sci_set_mctrl,
.get_mctrl = sci_get_mctrl,
.start_tx = sci_start_tx,
.stop_tx = sci_stop_tx,
.stop_rx = sci_stop_rx,
.break_ctl = sci_break_ctl,
.startup = sci_startup,
.shutdown = sci_shutdown,
.set_termios = sci_set_termios,
.pm = sci_pm,
.type = sci_type,
.release_port = sci_release_port,
.request_port = sci_request_port,
.config_port = sci_config_port,
.verify_port = sci_verify_port,
#ifdef CONFIG_CONSOLE_POLL
.poll_get_char = sci_poll_get_char,
.poll_put_char = sci_poll_put_char,
#endif
};
static int sci_init_clocks(struct sci_port *sci_port, struct device *dev)
{
const char *clk_names[] = {
[SCI_FCK] = "fck",
[SCI_SCK] = "sck",
[SCI_BRG_INT] = "brg_int",
[SCI_SCIF_CLK] = "scif_clk",
};
struct clk *clk;
unsigned int i;
if (sci_port->cfg->type == PORT_HSCIF)
clk_names[SCI_SCK] = "hsck";
for (i = 0; i < SCI_NUM_CLKS; i++) {
clk = devm_clk_get(dev, clk_names[i]);
if (PTR_ERR(clk) == -EPROBE_DEFER)
return -EPROBE_DEFER;
if (IS_ERR(clk) && i == SCI_FCK) {
/*
* "fck" used to be called "sci_ick", and we need to
* maintain DT backward compatibility.
*/
clk = devm_clk_get(dev, "sci_ick");
if (PTR_ERR(clk) == -EPROBE_DEFER)
return -EPROBE_DEFER;
if (!IS_ERR(clk))
goto found;
/*
* Not all SH platforms declare a clock lookup entry
* for SCI devices, in which case we need to get the
* global "peripheral_clk" clock.
*/
clk = devm_clk_get(dev, "peripheral_clk");
if (!IS_ERR(clk))
goto found;
dev_err(dev, "failed to get %s (%ld)\n", clk_names[i],
PTR_ERR(clk));
return PTR_ERR(clk);
}
found:
if (IS_ERR(clk))
dev_dbg(dev, "failed to get %s (%ld)\n", clk_names[i],
PTR_ERR(clk));
else
dev_dbg(dev, "clk %s is %pC rate %pCr\n", clk_names[i],
clk, clk);
sci_port->clks[i] = IS_ERR(clk) ? NULL : clk;
}
return 0;
}
static int sci_init_single(struct platform_device *dev,
struct sci_port *sci_port, unsigned int index,
struct plat_sci_port *p, bool early)
{
struct uart_port *port = &sci_port->port;
const struct resource *res;
unsigned int i;
int ret;
sci_port->cfg = p;
port->ops = &sci_uart_ops;
port->iotype = UPIO_MEM;
port->line = index;
res = platform_get_resource(dev, IORESOURCE_MEM, 0);
if (res == NULL)
return -ENOMEM;
port->mapbase = res->start;
sci_port->reg_size = resource_size(res);
for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i)
sci_port->irqs[i] = platform_get_irq(dev, i);
/* The SCI generates several interrupts. They can be muxed together or
* connected to different interrupt lines. In the muxed case only one
* interrupt resource is specified. In the non-muxed case three or four
* interrupt resources are specified, as the BRI interrupt is optional.
*/
if (sci_port->irqs[0] < 0)
return -ENXIO;
if (sci_port->irqs[1] < 0) {
sci_port->irqs[1] = sci_port->irqs[0];
sci_port->irqs[2] = sci_port->irqs[0];
sci_port->irqs[3] = sci_port->irqs[0];
}
if (p->regtype == SCIx_PROBE_REGTYPE) {
ret = sci_probe_regmap(p);
if (unlikely(ret))
return ret;
}
switch (p->type) {
case PORT_SCIFB:
port->fifosize = 256;
sci_port->overrun_reg = SCxSR;
sci_port->overrun_mask = SCIFA_ORER;
sci_port->sampling_rate = 16;
break;
case PORT_HSCIF:
port->fifosize = 128;
sci_port->overrun_reg = SCLSR;
sci_port->overrun_mask = SCLSR_ORER;
sci_port->sampling_rate = 0;
break;
case PORT_SCIFA:
port->fifosize = 64;
sci_port->overrun_reg = SCxSR;
sci_port->overrun_mask = SCIFA_ORER;
sci_port->sampling_rate = 16;
break;
case PORT_SCIF:
port->fifosize = 16;
if (p->regtype == SCIx_SH7705_SCIF_REGTYPE) {
sci_port->overrun_reg = SCxSR;
sci_port->overrun_mask = SCIFA_ORER;
sci_port->sampling_rate = 16;
} else {
sci_port->overrun_reg = SCLSR;
sci_port->overrun_mask = SCLSR_ORER;
sci_port->sampling_rate = 32;
}
break;
default:
port->fifosize = 1;
sci_port->overrun_reg = SCxSR;
sci_port->overrun_mask = SCI_ORER;
sci_port->sampling_rate = 32;
break;
}
/* SCIFA on sh7723 and sh7724 need a custom sampling rate that doesn't
* match the SoC datasheet, this should be investigated. Let platform
* data override the sampling rate for now.
*/
if (p->sampling_rate)
sci_port->sampling_rate = p->sampling_rate;
if (!early) {
ret = sci_init_clocks(sci_port, &dev->dev);
if (ret < 0)
return ret;
port->dev = &dev->dev;
pm_runtime_enable(&dev->dev);
}
sci_port->break_timer.data = (unsigned long)sci_port;
sci_port->break_timer.function = sci_break_timer;
init_timer(&sci_port->break_timer);
/*
* Establish some sensible defaults for the error detection.
*/
if (p->type == PORT_SCI) {
sci_port->error_mask = SCI_DEFAULT_ERROR_MASK;
sci_port->error_clear = SCI_ERROR_CLEAR;
} else {
sci_port->error_mask = SCIF_DEFAULT_ERROR_MASK;
sci_port->error_clear = SCIF_ERROR_CLEAR;
}
/*
* Make the error mask inclusive of overrun detection, if
* supported.
*/
if (sci_port->overrun_reg == SCxSR) {
sci_port->error_mask |= sci_port->overrun_mask;
sci_port->error_clear &= ~sci_port->overrun_mask;
}
port->type = p->type;
port->flags = UPF_FIXED_PORT | p->flags;
port->regshift = p->regshift;
/*
* The UART port needs an IRQ value, so we peg this to the RX IRQ
* for the multi-IRQ ports, which is where we are primarily
* concerned with the shutdown path synchronization.
*
* For the muxed case there's nothing more to do.
*/
port->irq = sci_port->irqs[SCIx_RXI_IRQ];
port->irqflags = 0;
port->serial_in = sci_serial_in;
port->serial_out = sci_serial_out;
if (p->dma_slave_tx > 0 && p->dma_slave_rx > 0)
dev_dbg(port->dev, "DMA tx %d, rx %d\n",
p->dma_slave_tx, p->dma_slave_rx);
return 0;
}
static void sci_cleanup_single(struct sci_port *port)
{
pm_runtime_disable(port->port.dev);
}
#ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
static void serial_console_putchar(struct uart_port *port, int ch)
{
sci_poll_put_char(port, ch);
}
/*
* Print a string to the serial port trying not to disturb
* any possible real use of the port...
*/
static void serial_console_write(struct console *co, const char *s,
unsigned count)
{
struct sci_port *sci_port = &sci_ports[co->index];
struct uart_port *port = &sci_port->port;
unsigned short bits, ctrl, ctrl_temp;
unsigned long flags;
int locked = 1;
local_irq_save(flags);
if (port->sysrq)
locked = 0;
else if (oops_in_progress)
locked = spin_trylock(&port->lock);
else
spin_lock(&port->lock);
/* first save SCSCR then disable interrupts, keep clock source */
ctrl = serial_port_in(port, SCSCR);
ctrl_temp = (sci_port->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0)) |
(ctrl & (SCSCR_CKE1 | SCSCR_CKE0));
serial_port_out(port, SCSCR, ctrl_temp);
uart_console_write(port, s, count, serial_console_putchar);
/* wait until fifo is empty and last bit has been transmitted */
bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
while ((serial_port_in(port, SCxSR) & bits) != bits)
cpu_relax();
/* restore the SCSCR */
serial_port_out(port, SCSCR, ctrl);
if (locked)
spin_unlock(&port->lock);
local_irq_restore(flags);
}
static int serial_console_setup(struct console *co, char *options)
{
struct sci_port *sci_port;
struct uart_port *port;
int baud = 115200;
int bits = 8;
int parity = 'n';
int flow = 'n';
int ret;
/*
* Refuse to handle any bogus ports.
*/
if (co->index < 0 || co->index >= SCI_NPORTS)
return -ENODEV;
sci_port = &sci_ports[co->index];
port = &sci_port->port;
/*
* Refuse to handle uninitialized ports.
*/
if (!port->ops)
return -ENODEV;
ret = sci_remap_port(port);
if (unlikely(ret != 0))
return ret;
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
return uart_set_options(port, co, baud, parity, bits, flow);
}
static struct console serial_console = {
.name = "ttySC",
.device = uart_console_device,
.write = serial_console_write,
.setup = serial_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &sci_uart_driver,
};
static struct console early_serial_console = {
.name = "early_ttySC",
.write = serial_console_write,
.flags = CON_PRINTBUFFER,
.index = -1,
};
static char early_serial_buf[32];
static int sci_probe_earlyprintk(struct platform_device *pdev)
{
struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev);
if (early_serial_console.data)
return -EEXIST;
early_serial_console.index = pdev->id;
sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true);
serial_console_setup(&early_serial_console, early_serial_buf);
if (!strstr(early_serial_buf, "keep"))
early_serial_console.flags |= CON_BOOT;
register_console(&early_serial_console);
return 0;
}
#define SCI_CONSOLE (&serial_console)
#else
static inline int sci_probe_earlyprintk(struct platform_device *pdev)
{
return -EINVAL;
}
#define SCI_CONSOLE NULL
#endif /* CONFIG_SERIAL_SH_SCI_CONSOLE */
static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized";
static struct uart_driver sci_uart_driver = {
.owner = THIS_MODULE,
.driver_name = "sci",
.dev_name = "ttySC",
.major = SCI_MAJOR,
.minor = SCI_MINOR_START,
.nr = SCI_NPORTS,
.cons = SCI_CONSOLE,
};
static int sci_remove(struct platform_device *dev)
{
struct sci_port *port = platform_get_drvdata(dev);
uart_remove_one_port(&sci_uart_driver, &port->port);
sci_cleanup_single(port);
return 0;
}
#define SCI_OF_DATA(type, regtype) (void *)((type) << 16 | (regtype))
#define SCI_OF_TYPE(data) ((unsigned long)(data) >> 16)
#define SCI_OF_REGTYPE(data) ((unsigned long)(data) & 0xffff)
static const struct of_device_id of_sci_match[] = {
/* SoC-specific types */
{
.compatible = "renesas,scif-r7s72100",
.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH2_SCIF_FIFODATA_REGTYPE),
},
/* Family-specific types */
{
.compatible = "renesas,rcar-gen1-scif",
.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
}, {
.compatible = "renesas,rcar-gen2-scif",
.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
}, {
.compatible = "renesas,rcar-gen3-scif",
.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
},
/* Generic types */
{
.compatible = "renesas,scif",
.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_REGTYPE),
}, {
.compatible = "renesas,scifa",
.data = SCI_OF_DATA(PORT_SCIFA, SCIx_SCIFA_REGTYPE),
}, {
.compatible = "renesas,scifb",
.data = SCI_OF_DATA(PORT_SCIFB, SCIx_SCIFB_REGTYPE),
}, {
.compatible = "renesas,hscif",
.data = SCI_OF_DATA(PORT_HSCIF, SCIx_HSCIF_REGTYPE),
}, {
.compatible = "renesas,sci",
.data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE),
}, {
/* Terminator */
},
};
MODULE_DEVICE_TABLE(of, of_sci_match);
static struct plat_sci_port *
sci_parse_dt(struct platform_device *pdev, unsigned int *dev_id)
{
struct device_node *np = pdev->dev.of_node;
const struct of_device_id *match;
struct plat_sci_port *p;
int id;
if (!IS_ENABLED(CONFIG_OF) || !np)
return NULL;
match = of_match_node(of_sci_match, np);
if (!match)
return NULL;
p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
if (!p)
return NULL;
/* Get the line number from the aliases node. */
id = of_alias_get_id(np, "serial");
if (id < 0) {
dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
return NULL;
}
*dev_id = id;
p->flags = UPF_IOREMAP | UPF_BOOT_AUTOCONF;
p->type = SCI_OF_TYPE(match->data);
p->regtype = SCI_OF_REGTYPE(match->data);
p->scscr = SCSCR_RE | SCSCR_TE;
return p;
}
static int sci_probe_single(struct platform_device *dev,
unsigned int index,
struct plat_sci_port *p,
struct sci_port *sciport)
{
int ret;
/* Sanity check */
if (unlikely(index >= SCI_NPORTS)) {
dev_notice(&dev->dev, "Attempting to register port %d when only %d are available\n",
index+1, SCI_NPORTS);
dev_notice(&dev->dev, "Consider bumping CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
return -EINVAL;
}
ret = sci_init_single(dev, sciport, index, p, false);
if (ret)
return ret;
ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
if (ret) {
sci_cleanup_single(sciport);
return ret;
}
return 0;
}
static int sci_probe(struct platform_device *dev)
{
struct plat_sci_port *p;
struct sci_port *sp;
unsigned int dev_id;
int ret;
/*
* If we've come here via earlyprintk initialization, head off to
* the special early probe. We don't have sufficient device state
* to make it beyond this yet.
*/
if (is_early_platform_device(dev))
return sci_probe_earlyprintk(dev);
if (dev->dev.of_node) {
p = sci_parse_dt(dev, &dev_id);
if (p == NULL)
return -EINVAL;
} else {
p = dev->dev.platform_data;
if (p == NULL) {
dev_err(&dev->dev, "no platform data supplied\n");
return -EINVAL;
}
dev_id = dev->id;
}
sp = &sci_ports[dev_id];
platform_set_drvdata(dev, sp);
ret = sci_probe_single(dev, dev_id, p, sp);
if (ret)
return ret;
#ifdef CONFIG_SH_STANDARD_BIOS
sh_bios_gdb_detach();
#endif
return 0;
}
static __maybe_unused int sci_suspend(struct device *dev)
{
struct sci_port *sport = dev_get_drvdata(dev);
if (sport)
uart_suspend_port(&sci_uart_driver, &sport->port);
return 0;
}
static __maybe_unused int sci_resume(struct device *dev)
{
struct sci_port *sport = dev_get_drvdata(dev);
if (sport)
uart_resume_port(&sci_uart_driver, &sport->port);
return 0;
}
static SIMPLE_DEV_PM_OPS(sci_dev_pm_ops, sci_suspend, sci_resume);
static struct platform_driver sci_driver = {
.probe = sci_probe,
.remove = sci_remove,
.driver = {
.name = "sh-sci",
.pm = &sci_dev_pm_ops,
.of_match_table = of_match_ptr(of_sci_match),
},
};
static int __init sci_init(void)
{
int ret;
pr_info("%s\n", banner);
ret = uart_register_driver(&sci_uart_driver);
if (likely(ret == 0)) {
ret = platform_driver_register(&sci_driver);
if (unlikely(ret))
uart_unregister_driver(&sci_uart_driver);
}
return ret;
}
static void __exit sci_exit(void)
{
platform_driver_unregister(&sci_driver);
uart_unregister_driver(&sci_uart_driver);
}
#ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
early_platform_init_buffer("earlyprintk", &sci_driver,
early_serial_buf, ARRAY_SIZE(early_serial_buf));
#endif
module_init(sci_init);
module_exit(sci_exit);
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:sh-sci");
MODULE_AUTHOR("Paul Mundt");
MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver");
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