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WSL2-Linux-Kernel/drivers/serial/max3107.c

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30 KiB
C
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/*
* max3107.c - spi uart protocol driver for Maxim 3107
* Based on max3100.c
* by Christian Pellegrin <chripell@evolware.org>
* and max3110.c
* by Feng Tang <feng.tang@intel.com>
*
* Copyright (C) Aavamobile 2009
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
*/
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/serial_core.h>
#include <linux/serial.h>
#include <linux/gpio.h>
#include <linux/spi/spi.h>
#include <linux/freezer.h>
#include "max3107.h"
static const struct baud_table brg26_ext[] = {
{ 300, MAX3107_BRG26_B300 },
{ 600, MAX3107_BRG26_B600 },
{ 1200, MAX3107_BRG26_B1200 },
{ 2400, MAX3107_BRG26_B2400 },
{ 4800, MAX3107_BRG26_B4800 },
{ 9600, MAX3107_BRG26_B9600 },
{ 19200, MAX3107_BRG26_B19200 },
{ 57600, MAX3107_BRG26_B57600 },
{ 115200, MAX3107_BRG26_B115200 },
{ 230400, MAX3107_BRG26_B230400 },
{ 460800, MAX3107_BRG26_B460800 },
{ 921600, MAX3107_BRG26_B921600 },
{ 0, 0 }
};
static const struct baud_table brg13_int[] = {
{ 300, MAX3107_BRG13_IB300 },
{ 600, MAX3107_BRG13_IB600 },
{ 1200, MAX3107_BRG13_IB1200 },
{ 2400, MAX3107_BRG13_IB2400 },
{ 4800, MAX3107_BRG13_IB4800 },
{ 9600, MAX3107_BRG13_IB9600 },
{ 19200, MAX3107_BRG13_IB19200 },
{ 57600, MAX3107_BRG13_IB57600 },
{ 115200, MAX3107_BRG13_IB115200 },
{ 230400, MAX3107_BRG13_IB230400 },
{ 460800, MAX3107_BRG13_IB460800 },
{ 921600, MAX3107_BRG13_IB921600 },
{ 0, 0 }
};
static u32 get_new_brg(int baud, struct max3107_port *s)
{
int i;
const struct baud_table *baud_tbl = s->baud_tbl;
for (i = 0; i < 13; i++) {
if (baud == baud_tbl[i].baud)
return baud_tbl[i].new_brg;
}
return 0;
}
/* Perform SPI transfer for write/read of device register(s) */
int max3107_rw(struct max3107_port *s, u8 *tx, u8 *rx, int len)
{
struct spi_message spi_msg;
struct spi_transfer spi_xfer;
/* Initialize SPI ,message */
spi_message_init(&spi_msg);
/* Initialize SPI transfer */
memset(&spi_xfer, 0, sizeof spi_xfer);
spi_xfer.len = len;
spi_xfer.tx_buf = tx;
spi_xfer.rx_buf = rx;
spi_xfer.speed_hz = MAX3107_SPI_SPEED;
/* Add SPI transfer to SPI message */
spi_message_add_tail(&spi_xfer, &spi_msg);
#ifdef DBG_TRACE_SPI_DATA
{
int i;
pr_info("tx len %d:\n", spi_xfer.len);
for (i = 0 ; i < spi_xfer.len && i < 32 ; i++)
pr_info(" %x", ((u8 *)spi_xfer.tx_buf)[i]);
pr_info("\n");
}
#endif
/* Perform synchronous SPI transfer */
if (spi_sync(s->spi, &spi_msg)) {
dev_err(&s->spi->dev, "spi_sync failure\n");
return -EIO;
}
#ifdef DBG_TRACE_SPI_DATA
if (spi_xfer.rx_buf) {
int i;
pr_info("rx len %d:\n", spi_xfer.len);
for (i = 0 ; i < spi_xfer.len && i < 32 ; i++)
pr_info(" %x", ((u8 *)spi_xfer.rx_buf)[i]);
pr_info("\n");
}
#endif
return 0;
}
EXPORT_SYMBOL_GPL(max3107_rw);
/* Puts received data to circular buffer */
static void put_data_to_circ_buf(struct max3107_port *s, unsigned char *data,
int len)
{
struct uart_port *port = &s->port;
struct tty_struct *tty;
if (!port->state)
return;
tty = port->state->port.tty;
if (!tty)
return;
/* Insert received data */
tty_insert_flip_string(tty, data, len);
/* Update RX counter */
port->icount.rx += len;
}
/* Handle data receiving */
static void max3107_handlerx(struct max3107_port *s, u16 rxlvl)
{
int i;
int j;
int len; /* SPI transfer buffer length */
u16 *buf;
u8 *valid_str;
if (!s->rx_enabled)
/* RX is disabled */
return;
if (rxlvl == 0) {
/* RX fifo is empty */
return;
} else if (rxlvl >= MAX3107_RX_FIFO_SIZE) {
dev_warn(&s->spi->dev, "Possible RX FIFO overrun %d\n", rxlvl);
/* Ensure sanity of RX level */
rxlvl = MAX3107_RX_FIFO_SIZE;
}
if ((s->rxbuf == 0) || (s->rxstr == 0)) {
dev_warn(&s->spi->dev, "Rx buffer/str isn't ready\n");
return;
}
buf = s->rxbuf;
valid_str = s->rxstr;
while (rxlvl) {
pr_debug("rxlvl %d\n", rxlvl);
/* Clear buffer */
memset(buf, 0, sizeof(u16) * (MAX3107_RX_FIFO_SIZE + 2));
len = 0;
if (s->irqen_reg & MAX3107_IRQ_RXFIFO_BIT) {
/* First disable RX FIFO interrupt */
pr_debug("Disabling RX INT\n");
buf[0] = (MAX3107_WRITE_BIT | MAX3107_IRQEN_REG);
s->irqen_reg &= ~MAX3107_IRQ_RXFIFO_BIT;
buf[0] |= s->irqen_reg;
len++;
}
/* Just increase the length by amount of words in FIFO since
* buffer was zeroed and SPI transfer of 0x0000 means reading
* from RX FIFO
*/
len += rxlvl;
/* Append RX level query */
buf[len] = MAX3107_RXFIFOLVL_REG;
len++;
/* Perform the SPI transfer */
if (max3107_rw(s, (u8 *)buf, (u8 *)buf, len * 2)) {
dev_err(&s->spi->dev, "SPI transfer for RX h failed\n");
return;
}
/* Skip RX FIFO interrupt disabling word if it was added */
j = ((len - 1) - rxlvl);
/* Read received words */
for (i = 0; i < rxlvl; i++, j++)
valid_str[i] = (u8)buf[j];
put_data_to_circ_buf(s, valid_str, rxlvl);
/* Get new RX level */
rxlvl = (buf[len - 1] & MAX3107_SPI_RX_DATA_MASK);
}
if (s->rx_enabled) {
/* RX still enabled, re-enable RX FIFO interrupt */
pr_debug("Enabling RX INT\n");
buf[0] = (MAX3107_WRITE_BIT | MAX3107_IRQEN_REG);
s->irqen_reg |= MAX3107_IRQ_RXFIFO_BIT;
buf[0] |= s->irqen_reg;
if (max3107_rw(s, (u8 *)buf, NULL, 2))
dev_err(&s->spi->dev, "RX FIFO INT enabling failed\n");
}
/* Push the received data to receivers */
if (s->port.state->port.tty)
tty_flip_buffer_push(s->port.state->port.tty);
}
/* Handle data sending */
static void max3107_handletx(struct max3107_port *s)
{
struct circ_buf *xmit = &s->port.state->xmit;
int i;
unsigned long flags;
int len; /* SPI transfer buffer length */
u16 *buf;
if (!s->tx_fifo_empty)
/* Don't send more data before previous data is sent */
return;
if (uart_circ_empty(xmit) || uart_tx_stopped(&s->port))
/* No data to send or TX is stopped */
return;
if (!s->txbuf) {
dev_warn(&s->spi->dev, "Txbuf isn't ready\n");
return;
}
buf = s->txbuf;
/* Get length of data pending in circular buffer */
len = uart_circ_chars_pending(xmit);
if (len) {
/* Limit to size of TX FIFO */
if (len > MAX3107_TX_FIFO_SIZE)
len = MAX3107_TX_FIFO_SIZE;
pr_debug("txlen %d\n", len);
/* Update TX counter */
s->port.icount.tx += len;
/* TX FIFO will no longer be empty */
s->tx_fifo_empty = 0;
i = 0;
if (s->irqen_reg & MAX3107_IRQ_TXEMPTY_BIT) {
/* First disable TX empty interrupt */
pr_debug("Disabling TE INT\n");
buf[i] = (MAX3107_WRITE_BIT | MAX3107_IRQEN_REG);
s->irqen_reg &= ~MAX3107_IRQ_TXEMPTY_BIT;
buf[i] |= s->irqen_reg;
i++;
len++;
}
/* Add data to send */
spin_lock_irqsave(&s->port.lock, flags);
for ( ; i < len ; i++) {
buf[i] = (MAX3107_WRITE_BIT | MAX3107_THR_REG);
buf[i] |= ((u16)xmit->buf[xmit->tail] &
MAX3107_SPI_TX_DATA_MASK);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
}
spin_unlock_irqrestore(&s->port.lock, flags);
if (!(s->irqen_reg & MAX3107_IRQ_TXEMPTY_BIT)) {
/* Enable TX empty interrupt */
pr_debug("Enabling TE INT\n");
buf[i] = (MAX3107_WRITE_BIT | MAX3107_IRQEN_REG);
s->irqen_reg |= MAX3107_IRQ_TXEMPTY_BIT;
buf[i] |= s->irqen_reg;
i++;
len++;
}
if (!s->tx_enabled) {
/* Enable TX */
pr_debug("Enable TX\n");
buf[i] = (MAX3107_WRITE_BIT | MAX3107_MODE1_REG);
spin_lock_irqsave(&s->data_lock, flags);
s->mode1_reg &= ~MAX3107_MODE1_TXDIS_BIT;
buf[i] |= s->mode1_reg;
spin_unlock_irqrestore(&s->data_lock, flags);
s->tx_enabled = 1;
i++;
len++;
}
/* Perform the SPI transfer */
if (max3107_rw(s, (u8 *)buf, NULL, len*2)) {
dev_err(&s->spi->dev,
"SPI transfer TX handling failed\n");
return;
}
}
/* Indicate wake up if circular buffer is getting low on data */
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&s->port);
}
/* Handle interrupts
* Also reads and returns current RX FIFO level
*/
static u16 handle_interrupt(struct max3107_port *s)
{
u16 buf[4]; /* Buffer for SPI transfers */
u8 irq_status;
u16 rx_level;
unsigned long flags;
/* Read IRQ status register */
buf[0] = MAX3107_IRQSTS_REG;
/* Read status IRQ status register */
buf[1] = MAX3107_STS_IRQSTS_REG;
/* Read LSR IRQ status register */
buf[2] = MAX3107_LSR_IRQSTS_REG;
/* Query RX level */
buf[3] = MAX3107_RXFIFOLVL_REG;
if (max3107_rw(s, (u8 *)buf, (u8 *)buf, 8)) {
dev_err(&s->spi->dev,
"SPI transfer for INTR handling failed\n");
return 0;
}
irq_status = (u8)buf[0];
pr_debug("IRQSTS %x\n", irq_status);
rx_level = (buf[3] & MAX3107_SPI_RX_DATA_MASK);
if (irq_status & MAX3107_IRQ_LSR_BIT) {
/* LSR interrupt */
if (buf[2] & MAX3107_LSR_RXTO_BIT)
/* RX timeout interrupt,
* handled by normal RX handling
*/
pr_debug("RX TO INT\n");
}
if (irq_status & MAX3107_IRQ_TXEMPTY_BIT) {
/* Tx empty interrupt,
* disable TX and set tx_fifo_empty flag
*/
pr_debug("TE INT, disabling TX\n");
buf[0] = (MAX3107_WRITE_BIT | MAX3107_MODE1_REG);
spin_lock_irqsave(&s->data_lock, flags);
s->mode1_reg |= MAX3107_MODE1_TXDIS_BIT;
buf[0] |= s->mode1_reg;
spin_unlock_irqrestore(&s->data_lock, flags);
if (max3107_rw(s, (u8 *)buf, NULL, 2))
dev_err(&s->spi->dev, "SPI transfer TX dis failed\n");
s->tx_enabled = 0;
s->tx_fifo_empty = 1;
}
if (irq_status & MAX3107_IRQ_RXFIFO_BIT)
/* RX FIFO interrupt,
* handled by normal RX handling
*/
pr_debug("RFIFO INT\n");
/* Return RX level */
return rx_level;
}
/* Trigger work thread*/
static void max3107_dowork(struct max3107_port *s)
{
if (!work_pending(&s->work) && !freezing(current) && !s->suspended)
queue_work(s->workqueue, &s->work);
else
dev_warn(&s->spi->dev, "interrup isn't serviced normally!\n");
}
/* Work thread */
static void max3107_work(struct work_struct *w)
{
struct max3107_port *s = container_of(w, struct max3107_port, work);
u16 rxlvl = 0;
int len; /* SPI transfer buffer length */
u16 buf[5]; /* Buffer for SPI transfers */
unsigned long flags;
/* Start by reading current RX FIFO level */
buf[0] = MAX3107_RXFIFOLVL_REG;
if (max3107_rw(s, (u8 *)buf, (u8 *)buf, 2)) {
dev_err(&s->spi->dev, "SPI transfer RX lev failed\n");
rxlvl = 0;
} else {
rxlvl = (buf[0] & MAX3107_SPI_RX_DATA_MASK);
}
do {
pr_debug("rxlvl %d\n", rxlvl);
/* Handle RX */
max3107_handlerx(s, rxlvl);
rxlvl = 0;
if (s->handle_irq) {
/* Handle pending interrupts
* We also get new RX FIFO level since new data may
* have been received while pushing received data to
* receivers
*/
s->handle_irq = 0;
rxlvl = handle_interrupt(s);
}
/* Handle TX */
max3107_handletx(s);
/* Handle configuration changes */
len = 0;
spin_lock_irqsave(&s->data_lock, flags);
if (s->mode1_commit) {
pr_debug("mode1_commit\n");
buf[len] = (MAX3107_WRITE_BIT | MAX3107_MODE1_REG);
buf[len++] |= s->mode1_reg;
s->mode1_commit = 0;
}
if (s->lcr_commit) {
pr_debug("lcr_commit\n");
buf[len] = (MAX3107_WRITE_BIT | MAX3107_LCR_REG);
buf[len++] |= s->lcr_reg;
s->lcr_commit = 0;
}
if (s->brg_commit) {
pr_debug("brg_commit\n");
buf[len] = (MAX3107_WRITE_BIT | MAX3107_BRGDIVMSB_REG);
buf[len++] |= ((s->brg_cfg >> 16) &
MAX3107_SPI_TX_DATA_MASK);
buf[len] = (MAX3107_WRITE_BIT | MAX3107_BRGDIVLSB_REG);
buf[len++] |= ((s->brg_cfg >> 8) &
MAX3107_SPI_TX_DATA_MASK);
buf[len] = (MAX3107_WRITE_BIT | MAX3107_BRGCFG_REG);
buf[len++] |= ((s->brg_cfg) & 0xff);
s->brg_commit = 0;
}
spin_unlock_irqrestore(&s->data_lock, flags);
if (len > 0) {
if (max3107_rw(s, (u8 *)buf, NULL, len * 2))
dev_err(&s->spi->dev,
"SPI transfer config failed\n");
}
/* Reloop if interrupt handling indicated data in RX FIFO */
} while (rxlvl);
}
/* Set sleep mode */
static void max3107_set_sleep(struct max3107_port *s, int mode)
{
u16 buf[1]; /* Buffer for SPI transfer */
unsigned long flags;
pr_debug("enter, mode %d\n", mode);
buf[0] = (MAX3107_WRITE_BIT | MAX3107_MODE1_REG);
spin_lock_irqsave(&s->data_lock, flags);
switch (mode) {
case MAX3107_DISABLE_FORCED_SLEEP:
s->mode1_reg &= ~MAX3107_MODE1_FORCESLEEP_BIT;
break;
case MAX3107_ENABLE_FORCED_SLEEP:
s->mode1_reg |= MAX3107_MODE1_FORCESLEEP_BIT;
break;
case MAX3107_DISABLE_AUTOSLEEP:
s->mode1_reg &= ~MAX3107_MODE1_AUTOSLEEP_BIT;
break;
case MAX3107_ENABLE_AUTOSLEEP:
s->mode1_reg |= MAX3107_MODE1_AUTOSLEEP_BIT;
break;
default:
spin_unlock_irqrestore(&s->data_lock, flags);
dev_warn(&s->spi->dev, "invalid sleep mode\n");
return;
}
buf[0] |= s->mode1_reg;
spin_unlock_irqrestore(&s->data_lock, flags);
if (max3107_rw(s, (u8 *)buf, NULL, 2))
dev_err(&s->spi->dev, "SPI transfer sleep mode failed\n");
if (mode == MAX3107_DISABLE_AUTOSLEEP ||
mode == MAX3107_DISABLE_FORCED_SLEEP)
msleep(MAX3107_WAKEUP_DELAY);
}
/* Perform full register initialization */
static void max3107_register_init(struct max3107_port *s)
{
u16 buf[11]; /* Buffer for SPI transfers */
/* 1. Configure baud rate, 9600 as default */
s->baud = 9600;
/* the below is default*/
if (s->ext_clk) {
s->brg_cfg = MAX3107_BRG26_B9600;
s->baud_tbl = (struct baud_table *)brg26_ext;
} else {
s->brg_cfg = MAX3107_BRG13_IB9600;
s->baud_tbl = (struct baud_table *)brg13_int;
}
if (s->pdata->init)
s->pdata->init(s);
buf[0] = (MAX3107_WRITE_BIT | MAX3107_BRGDIVMSB_REG)
| ((s->brg_cfg >> 16) & MAX3107_SPI_TX_DATA_MASK);
buf[1] = (MAX3107_WRITE_BIT | MAX3107_BRGDIVLSB_REG)
| ((s->brg_cfg >> 8) & MAX3107_SPI_TX_DATA_MASK);
buf[2] = (MAX3107_WRITE_BIT | MAX3107_BRGCFG_REG)
| ((s->brg_cfg) & 0xff);
/* 2. Configure LCR register, 8N1 mode by default */
s->lcr_reg = MAX3107_LCR_WORD_LEN_8;
buf[3] = (MAX3107_WRITE_BIT | MAX3107_LCR_REG)
| s->lcr_reg;
/* 3. Configure MODE 1 register */
s->mode1_reg = 0;
/* Enable IRQ pin */
s->mode1_reg |= MAX3107_MODE1_IRQSEL_BIT;
/* Disable TX */
s->mode1_reg |= MAX3107_MODE1_TXDIS_BIT;
s->tx_enabled = 0;
/* RX is enabled */
s->rx_enabled = 1;
buf[4] = (MAX3107_WRITE_BIT | MAX3107_MODE1_REG)
| s->mode1_reg;
/* 4. Configure MODE 2 register */
buf[5] = (MAX3107_WRITE_BIT | MAX3107_MODE2_REG);
if (s->loopback) {
/* Enable loopback */
buf[5] |= MAX3107_MODE2_LOOPBACK_BIT;
}
/* Reset FIFOs */
buf[5] |= MAX3107_MODE2_FIFORST_BIT;
s->tx_fifo_empty = 1;
/* 5. Configure FIFO trigger level register */
buf[6] = (MAX3107_WRITE_BIT | MAX3107_FIFOTRIGLVL_REG);
/* RX FIFO trigger for 16 words, TX FIFO trigger not used */
buf[6] |= (MAX3107_FIFOTRIGLVL_RX(16) | MAX3107_FIFOTRIGLVL_TX(0));
/* 6. Configure flow control levels */
buf[7] = (MAX3107_WRITE_BIT | MAX3107_FLOWLVL_REG);
/* Flow control halt level 96, resume level 48 */
buf[7] |= (MAX3107_FLOWLVL_RES(48) | MAX3107_FLOWLVL_HALT(96));
/* 7. Configure flow control */
buf[8] = (MAX3107_WRITE_BIT | MAX3107_FLOWCTRL_REG);
/* Enable auto CTS and auto RTS flow control */
buf[8] |= (MAX3107_FLOWCTRL_AUTOCTS_BIT | MAX3107_FLOWCTRL_AUTORTS_BIT);
/* 8. Configure RX timeout register */
buf[9] = (MAX3107_WRITE_BIT | MAX3107_RXTO_REG);
/* Timeout after 48 character intervals */
buf[9] |= 0x0030;
/* 9. Configure LSR interrupt enable register */
buf[10] = (MAX3107_WRITE_BIT | MAX3107_LSR_IRQEN_REG);
/* Enable RX timeout interrupt */
buf[10] |= MAX3107_LSR_RXTO_BIT;
/* Perform SPI transfer */
if (max3107_rw(s, (u8 *)buf, NULL, 22))
dev_err(&s->spi->dev, "SPI transfer for init failed\n");
/* 10. Clear IRQ status register by reading it */
buf[0] = MAX3107_IRQSTS_REG;
/* 11. Configure interrupt enable register */
/* Enable LSR interrupt */
s->irqen_reg = MAX3107_IRQ_LSR_BIT;
/* Enable RX FIFO interrupt */
s->irqen_reg |= MAX3107_IRQ_RXFIFO_BIT;
buf[1] = (MAX3107_WRITE_BIT | MAX3107_IRQEN_REG)
| s->irqen_reg;
/* 12. Clear FIFO reset that was set in step 6 */
buf[2] = (MAX3107_WRITE_BIT | MAX3107_MODE2_REG);
if (s->loopback) {
/* Keep loopback enabled */
buf[2] |= MAX3107_MODE2_LOOPBACK_BIT;
}
/* Perform SPI transfer */
if (max3107_rw(s, (u8 *)buf, (u8 *)buf, 6))
dev_err(&s->spi->dev, "SPI transfer for init failed\n");
}
/* IRQ handler */
static irqreturn_t max3107_irq(int irqno, void *dev_id)
{
struct max3107_port *s = dev_id;
if (irqno != s->spi->irq) {
/* Unexpected IRQ */
return IRQ_NONE;
}
/* Indicate irq */
s->handle_irq = 1;
/* Trigger work thread */
max3107_dowork(s);
return IRQ_HANDLED;
}
/* HW suspension function
*
* Currently autosleep is used to decrease current consumption, alternative
* approach would be to set the chip to reset mode if UART is not being
* used but that would mess the GPIOs
*
*/
void max3107_hw_susp(struct max3107_port *s, int suspend)
{
pr_debug("enter, suspend %d\n", suspend);
if (suspend) {
/* Suspend requested,
* enable autosleep to decrease current consumption
*/
s->suspended = 1;
max3107_set_sleep(s, MAX3107_ENABLE_AUTOSLEEP);
} else {
/* Resume requested,
* disable autosleep
*/
s->suspended = 0;
max3107_set_sleep(s, MAX3107_DISABLE_AUTOSLEEP);
}
}
EXPORT_SYMBOL_GPL(max3107_hw_susp);
/* Modem status IRQ enabling */
static void max3107_enable_ms(struct uart_port *port)
{
/* Modem status not supported */
}
/* Data send function */
static void max3107_start_tx(struct uart_port *port)
{
struct max3107_port *s = container_of(port, struct max3107_port, port);
/* Trigger work thread for sending data */
max3107_dowork(s);
}
/* Function for checking that there is no pending transfers */
static unsigned int max3107_tx_empty(struct uart_port *port)
{
struct max3107_port *s = container_of(port, struct max3107_port, port);
pr_debug("returning %d\n",
(s->tx_fifo_empty && uart_circ_empty(&s->port.state->xmit)));
return s->tx_fifo_empty && uart_circ_empty(&s->port.state->xmit);
}
/* Function for stopping RX */
static void max3107_stop_rx(struct uart_port *port)
{
struct max3107_port *s = container_of(port, struct max3107_port, port);
unsigned long flags;
/* Set RX disabled in MODE 1 register */
spin_lock_irqsave(&s->data_lock, flags);
s->mode1_reg |= MAX3107_MODE1_RXDIS_BIT;
s->mode1_commit = 1;
spin_unlock_irqrestore(&s->data_lock, flags);
/* Set RX disabled */
s->rx_enabled = 0;
/* Trigger work thread for doing the actual configuration change */
max3107_dowork(s);
}
/* Function for returning control pin states */
static unsigned int max3107_get_mctrl(struct uart_port *port)
{
/* DCD and DSR are not wired and CTS/RTS is handled automatically
* so just indicate DSR and CAR asserted
*/
return TIOCM_DSR | TIOCM_CAR;
}
/* Function for setting control pin states */
static void max3107_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
/* DCD and DSR are not wired and CTS/RTS is hadnled automatically
* so do nothing
*/
}
/* Function for configuring UART parameters */
static void max3107_set_termios(struct uart_port *port,
struct ktermios *termios,
struct ktermios *old)
{
struct max3107_port *s = container_of(port, struct max3107_port, port);
struct tty_struct *tty;
int baud;
u16 new_lcr = 0;
u32 new_brg = 0;
unsigned long flags;
if (!port->state)
return;
tty = port->state->port.tty;
if (!tty)
return;
/* Get new LCR register values */
/* Word size */
if ((termios->c_cflag & CSIZE) == CS7)
new_lcr |= MAX3107_LCR_WORD_LEN_7;
else
new_lcr |= MAX3107_LCR_WORD_LEN_8;
/* Parity */
if (termios->c_cflag & PARENB) {
new_lcr |= MAX3107_LCR_PARITY_BIT;
if (!(termios->c_cflag & PARODD))
new_lcr |= MAX3107_LCR_EVENPARITY_BIT;
}
/* Stop bits */
if (termios->c_cflag & CSTOPB) {
/* 2 stop bits */
new_lcr |= MAX3107_LCR_STOPLEN_BIT;
}
/* Mask termios capabilities we don't support */
termios->c_cflag &= ~CMSPAR;
/* Set status ignore mask */
s->port.ignore_status_mask = 0;
if (termios->c_iflag & IGNPAR)
s->port.ignore_status_mask |= MAX3107_ALL_ERRORS;
/* Set low latency to immediately handle pushed data */
s->port.state->port.tty->low_latency = 1;
/* Get new baud rate generator configuration */
baud = tty_get_baud_rate(tty);
spin_lock_irqsave(&s->data_lock, flags);
new_brg = get_new_brg(baud, s);
/* if can't find the corrent config, use previous */
if (!new_brg) {
baud = s->baud;
new_brg = s->brg_cfg;
}
spin_unlock_irqrestore(&s->data_lock, flags);
tty_termios_encode_baud_rate(termios, baud, baud);
s->baud = baud;
/* Update timeout according to new baud rate */
uart_update_timeout(port, termios->c_cflag, baud);
spin_lock_irqsave(&s->data_lock, flags);
if (s->lcr_reg != new_lcr) {
s->lcr_reg = new_lcr;
s->lcr_commit = 1;
}
if (s->brg_cfg != new_brg) {
s->brg_cfg = new_brg;
s->brg_commit = 1;
}
spin_unlock_irqrestore(&s->data_lock, flags);
/* Trigger work thread for doing the actual configuration change */
max3107_dowork(s);
}
/* Port shutdown function */
static void max3107_shutdown(struct uart_port *port)
{
struct max3107_port *s = container_of(port, struct max3107_port, port);
if (s->suspended && s->pdata->hw_suspend)
s->pdata->hw_suspend(s, 0);
/* Free the interrupt */
free_irq(s->spi->irq, s);
if (s->workqueue) {
/* Flush and destroy work queue */
flush_workqueue(s->workqueue);
destroy_workqueue(s->workqueue);
s->workqueue = NULL;
}
/* Suspend HW */
if (s->pdata->hw_suspend)
s->pdata->hw_suspend(s, 1);
}
/* Port startup function */
static int max3107_startup(struct uart_port *port)
{
struct max3107_port *s = container_of(port, struct max3107_port, port);
/* Initialize work queue */
s->workqueue = create_freezeable_workqueue("max3107");
if (!s->workqueue) {
dev_err(&s->spi->dev, "Workqueue creation failed\n");
return -EBUSY;
}
INIT_WORK(&s->work, max3107_work);
/* Setup IRQ */
if (request_irq(s->spi->irq, max3107_irq, IRQF_TRIGGER_FALLING,
"max3107", s)) {
dev_err(&s->spi->dev, "IRQ reguest failed\n");
destroy_workqueue(s->workqueue);
s->workqueue = NULL;
return -EBUSY;
}
/* Resume HW */
if (s->pdata->hw_suspend)
s->pdata->hw_suspend(s, 0);
/* Init registers */
max3107_register_init(s);
return 0;
}
/* Port type function */
static const char *max3107_type(struct uart_port *port)
{
struct max3107_port *s = container_of(port, struct max3107_port, port);
return s->spi->modalias;
}
/* Port release function */
static void max3107_release_port(struct uart_port *port)
{
/* Do nothing */
}
/* Port request function */
static int max3107_request_port(struct uart_port *port)
{
/* Do nothing */
return 0;
}
/* Port config function */
static void max3107_config_port(struct uart_port *port, int flags)
{
struct max3107_port *s = container_of(port, struct max3107_port, port);
s->port.type = PORT_MAX3107;
}
/* Port verify function */
static int max3107_verify_port(struct uart_port *port,
struct serial_struct *ser)
{
if (ser->type == PORT_UNKNOWN || ser->type == PORT_MAX3107)
return 0;
return -EINVAL;
}
/* Port stop TX function */
static void max3107_stop_tx(struct uart_port *port)
{
/* Do nothing */
}
/* Port break control function */
static void max3107_break_ctl(struct uart_port *port, int break_state)
{
/* We don't support break control, do nothing */
}
/* Port functions */
static struct uart_ops max3107_ops = {
.tx_empty = max3107_tx_empty,
.set_mctrl = max3107_set_mctrl,
.get_mctrl = max3107_get_mctrl,
.stop_tx = max3107_stop_tx,
.start_tx = max3107_start_tx,
.stop_rx = max3107_stop_rx,
.enable_ms = max3107_enable_ms,
.break_ctl = max3107_break_ctl,
.startup = max3107_startup,
.shutdown = max3107_shutdown,
.set_termios = max3107_set_termios,
.type = max3107_type,
.release_port = max3107_release_port,
.request_port = max3107_request_port,
.config_port = max3107_config_port,
.verify_port = max3107_verify_port,
};
/* UART driver data */
static struct uart_driver max3107_uart_driver = {
.owner = THIS_MODULE,
.driver_name = "ttyMAX",
.dev_name = "ttyMAX",
.nr = 1,
};
static int driver_registered = 0;
/* 'Generic' platform data */
static struct max3107_plat generic_plat_data = {
.loopback = 0,
.ext_clk = 1,
.hw_suspend = max3107_hw_susp,
.polled_mode = 0,
.poll_time = 0,
};
/*******************************************************************/
/**
* max3107_probe - SPI bus probe entry point
* @spi: the spi device
*
* SPI wants us to probe this device and if appropriate claim it.
* Perform any platform specific requirements and then initialise
* the device.
*/
int max3107_probe(struct spi_device *spi, struct max3107_plat *pdata)
{
struct max3107_port *s;
u16 buf[2]; /* Buffer for SPI transfers */
int retval;
pr_info("enter max3107 probe\n");
/* Allocate port structure */
s = kzalloc(sizeof(*s), GFP_KERNEL);
if (!s) {
pr_err("Allocating port structure failed\n");
return -ENOMEM;
}
s->pdata = pdata;
/* SPI Rx buffer
* +2 for RX FIFO interrupt
* disabling and RX level query
*/
s->rxbuf = kzalloc(sizeof(u16) * (MAX3107_RX_FIFO_SIZE+2), GFP_KERNEL);
if (!s->rxbuf) {
pr_err("Allocating RX buffer failed\n");
return -ENOMEM;
}
s->rxstr = kzalloc(sizeof(u8) * MAX3107_RX_FIFO_SIZE, GFP_KERNEL);
if (!s->rxstr) {
pr_err("Allocating RX buffer failed\n");
return -ENOMEM;
}
/* SPI Tx buffer
* SPI transfer buffer
* +3 for TX FIFO empty
* interrupt disabling and
* enabling and TX enabling
*/
s->txbuf = kzalloc(sizeof(u16) * MAX3107_TX_FIFO_SIZE + 3, GFP_KERNEL);
if (!s->txbuf) {
pr_err("Allocating TX buffer failed\n");
return -ENOMEM;
}
/* Initialize shared data lock */
spin_lock_init(&s->data_lock);
/* SPI intializations */
dev_set_drvdata(&spi->dev, s);
spi->mode = SPI_MODE_0;
spi->dev.platform_data = pdata;
spi->bits_per_word = 16;
s->ext_clk = pdata->ext_clk;
s->loopback = pdata->loopback;
spi_setup(spi);
s->spi = spi;
/* Check REV ID to ensure we are talking to what we expect */
buf[0] = MAX3107_REVID_REG;
if (max3107_rw(s, (u8 *)buf, (u8 *)buf, 2)) {
dev_err(&s->spi->dev, "SPI transfer for REVID read failed\n");
return -EIO;
}
if ((buf[0] & MAX3107_SPI_RX_DATA_MASK) != MAX3107_REVID1 &&
(buf[0] & MAX3107_SPI_RX_DATA_MASK) != MAX3107_REVID2) {
dev_err(&s->spi->dev, "REVID %x does not match\n",
(buf[0] & MAX3107_SPI_RX_DATA_MASK));
return -ENODEV;
}
/* Disable all interrupts */
buf[0] = (MAX3107_WRITE_BIT | MAX3107_IRQEN_REG | 0x0000);
buf[0] |= 0x0000;
/* Configure clock source */
buf[1] = (MAX3107_WRITE_BIT | MAX3107_CLKSRC_REG);
if (s->ext_clk) {
/* External clock */
buf[1] |= MAX3107_CLKSRC_EXTCLK_BIT;
}
/* PLL bypass ON */
buf[1] |= MAX3107_CLKSRC_PLLBYP_BIT;
/* Perform SPI transfer */
if (max3107_rw(s, (u8 *)buf, NULL, 4)) {
dev_err(&s->spi->dev, "SPI transfer for init failed\n");
return -EIO;
}
/* Register UART driver */
if (!driver_registered) {
retval = uart_register_driver(&max3107_uart_driver);
if (retval) {
dev_err(&s->spi->dev, "Registering UART driver failed\n");
return retval;
}
driver_registered = 1;
}
/* Initialize UART port data */
s->port.fifosize = 128;
s->port.ops = &max3107_ops;
s->port.line = 0;
s->port.dev = &spi->dev;
s->port.uartclk = 9600;
s->port.flags = UPF_SKIP_TEST | UPF_BOOT_AUTOCONF;
s->port.irq = s->spi->irq;
s->port.type = PORT_MAX3107;
/* Add UART port */
retval = uart_add_one_port(&max3107_uart_driver, &s->port);
if (retval < 0) {
dev_err(&s->spi->dev, "Adding UART port failed\n");
return retval;
}
if (pdata->configure) {
retval = pdata->configure(s);
if (retval < 0)
return retval;
}
/* Go to suspend mode */
if (pdata->hw_suspend)
pdata->hw_suspend(s, 1);
return 0;
}
EXPORT_SYMBOL_GPL(max3107_probe);
/* Driver remove function */
int max3107_remove(struct spi_device *spi)
{
struct max3107_port *s = dev_get_drvdata(&spi->dev);
pr_info("enter max3107 remove\n");
/* Remove port */
if (uart_remove_one_port(&max3107_uart_driver, &s->port))
dev_warn(&s->spi->dev, "Removing UART port failed\n");
/* Free TxRx buffer */
kfree(s->rxbuf);
kfree(s->rxstr);
kfree(s->txbuf);
/* Free port structure */
kfree(s);
return 0;
}
EXPORT_SYMBOL_GPL(max3107_remove);
/* Driver suspend function */
int max3107_suspend(struct spi_device *spi, pm_message_t state)
{
#ifdef CONFIG_PM
struct max3107_port *s = dev_get_drvdata(&spi->dev);
pr_debug("enter suspend\n");
/* Suspend UART port */
uart_suspend_port(&max3107_uart_driver, &s->port);
/* Go to suspend mode */
if (s->pdata->hw_suspend)
s->pdata->hw_suspend(s, 1);
#endif /* CONFIG_PM */
return 0;
}
EXPORT_SYMBOL_GPL(max3107_suspend);
/* Driver resume function */
int max3107_resume(struct spi_device *spi)
{
#ifdef CONFIG_PM
struct max3107_port *s = dev_get_drvdata(&spi->dev);
pr_debug("enter resume\n");
/* Resume from suspend */
if (s->pdata->hw_suspend)
s->pdata->hw_suspend(s, 0);
/* Resume UART port */
uart_resume_port(&max3107_uart_driver, &s->port);
#endif /* CONFIG_PM */
return 0;
}
EXPORT_SYMBOL_GPL(max3107_resume);
static int max3107_probe_generic(struct spi_device *spi)
{
return max3107_probe(spi, &generic_plat_data);
}
/* Spi driver data */
static struct spi_driver max3107_driver = {
.driver = {
.name = "max3107",
.bus = &spi_bus_type,
.owner = THIS_MODULE,
},
.probe = max3107_probe_generic,
.remove = __devexit_p(max3107_remove),
.suspend = max3107_suspend,
.resume = max3107_resume,
};
/* Driver init function */
static int __init max3107_init(void)
{
pr_info("enter max3107 init\n");
return spi_register_driver(&max3107_driver);
}
/* Driver exit function */
static void __exit max3107_exit(void)
{
pr_info("enter max3107 exit\n");
/* Unregister UART driver */
if (driver_registered)
uart_unregister_driver(&max3107_uart_driver);
spi_unregister_driver(&max3107_driver);
}
module_init(max3107_init);
module_exit(max3107_exit);
MODULE_DESCRIPTION("MAX3107 driver");
MODULE_AUTHOR("Aavamobile");
MODULE_ALIAS("max3107-spi");
MODULE_LICENSE("GPL v2");
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