818 строки
19 KiB
C
818 строки
19 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* i2c-ocores.c: I2C bus driver for OpenCores I2C controller
|
|
* (https://opencores.org/project/i2c/overview)
|
|
*
|
|
* Peter Korsgaard <peter@korsgaard.com>
|
|
*
|
|
* Support for the GRLIB port of the controller by
|
|
* Andreas Larsson <andreas@gaisler.com>
|
|
*/
|
|
|
|
#include <linux/clk.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/err.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/i2c.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/wait.h>
|
|
#include <linux/platform_data/i2c-ocores.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/io.h>
|
|
#include <linux/log2.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/jiffies.h>
|
|
|
|
/*
|
|
* 'process_lock' exists because ocores_process() and ocores_process_timeout()
|
|
* can't run in parallel.
|
|
*/
|
|
struct ocores_i2c {
|
|
void __iomem *base;
|
|
int iobase;
|
|
u32 reg_shift;
|
|
u32 reg_io_width;
|
|
unsigned long flags;
|
|
wait_queue_head_t wait;
|
|
struct i2c_adapter adap;
|
|
struct i2c_msg *msg;
|
|
int pos;
|
|
int nmsgs;
|
|
int state; /* see STATE_ */
|
|
spinlock_t process_lock;
|
|
struct clk *clk;
|
|
int ip_clock_khz;
|
|
int bus_clock_khz;
|
|
void (*setreg)(struct ocores_i2c *i2c, int reg, u8 value);
|
|
u8 (*getreg)(struct ocores_i2c *i2c, int reg);
|
|
};
|
|
|
|
/* registers */
|
|
#define OCI2C_PRELOW 0
|
|
#define OCI2C_PREHIGH 1
|
|
#define OCI2C_CONTROL 2
|
|
#define OCI2C_DATA 3
|
|
#define OCI2C_CMD 4 /* write only */
|
|
#define OCI2C_STATUS 4 /* read only, same address as OCI2C_CMD */
|
|
|
|
#define OCI2C_CTRL_IEN 0x40
|
|
#define OCI2C_CTRL_EN 0x80
|
|
|
|
#define OCI2C_CMD_START 0x91
|
|
#define OCI2C_CMD_STOP 0x41
|
|
#define OCI2C_CMD_READ 0x21
|
|
#define OCI2C_CMD_WRITE 0x11
|
|
#define OCI2C_CMD_READ_ACK 0x21
|
|
#define OCI2C_CMD_READ_NACK 0x29
|
|
#define OCI2C_CMD_IACK 0x01
|
|
|
|
#define OCI2C_STAT_IF 0x01
|
|
#define OCI2C_STAT_TIP 0x02
|
|
#define OCI2C_STAT_ARBLOST 0x20
|
|
#define OCI2C_STAT_BUSY 0x40
|
|
#define OCI2C_STAT_NACK 0x80
|
|
|
|
#define STATE_DONE 0
|
|
#define STATE_START 1
|
|
#define STATE_WRITE 2
|
|
#define STATE_READ 3
|
|
#define STATE_ERROR 4
|
|
|
|
#define TYPE_OCORES 0
|
|
#define TYPE_GRLIB 1
|
|
|
|
#define OCORES_FLAG_BROKEN_IRQ BIT(1) /* Broken IRQ for FU540-C000 SoC */
|
|
|
|
static void oc_setreg_8(struct ocores_i2c *i2c, int reg, u8 value)
|
|
{
|
|
iowrite8(value, i2c->base + (reg << i2c->reg_shift));
|
|
}
|
|
|
|
static void oc_setreg_16(struct ocores_i2c *i2c, int reg, u8 value)
|
|
{
|
|
iowrite16(value, i2c->base + (reg << i2c->reg_shift));
|
|
}
|
|
|
|
static void oc_setreg_32(struct ocores_i2c *i2c, int reg, u8 value)
|
|
{
|
|
iowrite32(value, i2c->base + (reg << i2c->reg_shift));
|
|
}
|
|
|
|
static void oc_setreg_16be(struct ocores_i2c *i2c, int reg, u8 value)
|
|
{
|
|
iowrite16be(value, i2c->base + (reg << i2c->reg_shift));
|
|
}
|
|
|
|
static void oc_setreg_32be(struct ocores_i2c *i2c, int reg, u8 value)
|
|
{
|
|
iowrite32be(value, i2c->base + (reg << i2c->reg_shift));
|
|
}
|
|
|
|
static inline u8 oc_getreg_8(struct ocores_i2c *i2c, int reg)
|
|
{
|
|
return ioread8(i2c->base + (reg << i2c->reg_shift));
|
|
}
|
|
|
|
static inline u8 oc_getreg_16(struct ocores_i2c *i2c, int reg)
|
|
{
|
|
return ioread16(i2c->base + (reg << i2c->reg_shift));
|
|
}
|
|
|
|
static inline u8 oc_getreg_32(struct ocores_i2c *i2c, int reg)
|
|
{
|
|
return ioread32(i2c->base + (reg << i2c->reg_shift));
|
|
}
|
|
|
|
static inline u8 oc_getreg_16be(struct ocores_i2c *i2c, int reg)
|
|
{
|
|
return ioread16be(i2c->base + (reg << i2c->reg_shift));
|
|
}
|
|
|
|
static inline u8 oc_getreg_32be(struct ocores_i2c *i2c, int reg)
|
|
{
|
|
return ioread32be(i2c->base + (reg << i2c->reg_shift));
|
|
}
|
|
|
|
static void oc_setreg_io_8(struct ocores_i2c *i2c, int reg, u8 value)
|
|
{
|
|
outb(value, i2c->iobase + reg);
|
|
}
|
|
|
|
static inline u8 oc_getreg_io_8(struct ocores_i2c *i2c, int reg)
|
|
{
|
|
return inb(i2c->iobase + reg);
|
|
}
|
|
|
|
static inline void oc_setreg(struct ocores_i2c *i2c, int reg, u8 value)
|
|
{
|
|
i2c->setreg(i2c, reg, value);
|
|
}
|
|
|
|
static inline u8 oc_getreg(struct ocores_i2c *i2c, int reg)
|
|
{
|
|
return i2c->getreg(i2c, reg);
|
|
}
|
|
|
|
static void ocores_process(struct ocores_i2c *i2c, u8 stat)
|
|
{
|
|
struct i2c_msg *msg = i2c->msg;
|
|
unsigned long flags;
|
|
|
|
/*
|
|
* If we spin here is because we are in timeout, so we are going
|
|
* to be in STATE_ERROR. See ocores_process_timeout()
|
|
*/
|
|
spin_lock_irqsave(&i2c->process_lock, flags);
|
|
|
|
if ((i2c->state == STATE_DONE) || (i2c->state == STATE_ERROR)) {
|
|
/* stop has been sent */
|
|
oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_IACK);
|
|
wake_up(&i2c->wait);
|
|
goto out;
|
|
}
|
|
|
|
/* error? */
|
|
if (stat & OCI2C_STAT_ARBLOST) {
|
|
i2c->state = STATE_ERROR;
|
|
oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_STOP);
|
|
goto out;
|
|
}
|
|
|
|
if ((i2c->state == STATE_START) || (i2c->state == STATE_WRITE)) {
|
|
i2c->state =
|
|
(msg->flags & I2C_M_RD) ? STATE_READ : STATE_WRITE;
|
|
|
|
if (stat & OCI2C_STAT_NACK) {
|
|
i2c->state = STATE_ERROR;
|
|
oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_STOP);
|
|
goto out;
|
|
}
|
|
} else {
|
|
msg->buf[i2c->pos++] = oc_getreg(i2c, OCI2C_DATA);
|
|
}
|
|
|
|
/* end of msg? */
|
|
if (i2c->pos == msg->len) {
|
|
i2c->nmsgs--;
|
|
i2c->msg++;
|
|
i2c->pos = 0;
|
|
msg = i2c->msg;
|
|
|
|
if (i2c->nmsgs) { /* end? */
|
|
/* send start? */
|
|
if (!(msg->flags & I2C_M_NOSTART)) {
|
|
u8 addr = i2c_8bit_addr_from_msg(msg);
|
|
|
|
i2c->state = STATE_START;
|
|
|
|
oc_setreg(i2c, OCI2C_DATA, addr);
|
|
oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_START);
|
|
goto out;
|
|
}
|
|
i2c->state = (msg->flags & I2C_M_RD)
|
|
? STATE_READ : STATE_WRITE;
|
|
} else {
|
|
i2c->state = STATE_DONE;
|
|
oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_STOP);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
if (i2c->state == STATE_READ) {
|
|
oc_setreg(i2c, OCI2C_CMD, i2c->pos == (msg->len-1) ?
|
|
OCI2C_CMD_READ_NACK : OCI2C_CMD_READ_ACK);
|
|
} else {
|
|
oc_setreg(i2c, OCI2C_DATA, msg->buf[i2c->pos++]);
|
|
oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_WRITE);
|
|
}
|
|
|
|
out:
|
|
spin_unlock_irqrestore(&i2c->process_lock, flags);
|
|
}
|
|
|
|
static irqreturn_t ocores_isr(int irq, void *dev_id)
|
|
{
|
|
struct ocores_i2c *i2c = dev_id;
|
|
u8 stat = oc_getreg(i2c, OCI2C_STATUS);
|
|
|
|
if (i2c->flags & OCORES_FLAG_BROKEN_IRQ) {
|
|
if ((stat & OCI2C_STAT_IF) && !(stat & OCI2C_STAT_BUSY))
|
|
return IRQ_NONE;
|
|
} else if (!(stat & OCI2C_STAT_IF)) {
|
|
return IRQ_NONE;
|
|
}
|
|
ocores_process(i2c, stat);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
/**
|
|
* Process timeout event
|
|
* @i2c: ocores I2C device instance
|
|
*/
|
|
static void ocores_process_timeout(struct ocores_i2c *i2c)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&i2c->process_lock, flags);
|
|
i2c->state = STATE_ERROR;
|
|
oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_STOP);
|
|
spin_unlock_irqrestore(&i2c->process_lock, flags);
|
|
}
|
|
|
|
/**
|
|
* Wait until something change in a given register
|
|
* @i2c: ocores I2C device instance
|
|
* @reg: register to query
|
|
* @mask: bitmask to apply on register value
|
|
* @val: expected result
|
|
* @timeout: timeout in jiffies
|
|
*
|
|
* Timeout is necessary to avoid to stay here forever when the chip
|
|
* does not answer correctly.
|
|
*
|
|
* Return: 0 on success, -ETIMEDOUT on timeout
|
|
*/
|
|
static int ocores_wait(struct ocores_i2c *i2c,
|
|
int reg, u8 mask, u8 val,
|
|
const unsigned long timeout)
|
|
{
|
|
unsigned long j;
|
|
|
|
j = jiffies + timeout;
|
|
while (1) {
|
|
u8 status = oc_getreg(i2c, reg);
|
|
|
|
if ((status & mask) == val)
|
|
break;
|
|
|
|
if (time_after(jiffies, j))
|
|
return -ETIMEDOUT;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Wait until is possible to process some data
|
|
* @i2c: ocores I2C device instance
|
|
*
|
|
* Used when the device is in polling mode (interrupts disabled).
|
|
*
|
|
* Return: 0 on success, -ETIMEDOUT on timeout
|
|
*/
|
|
static int ocores_poll_wait(struct ocores_i2c *i2c)
|
|
{
|
|
u8 mask;
|
|
int err;
|
|
|
|
if (i2c->state == STATE_DONE || i2c->state == STATE_ERROR) {
|
|
/* transfer is over */
|
|
mask = OCI2C_STAT_BUSY;
|
|
} else {
|
|
/* on going transfer */
|
|
mask = OCI2C_STAT_TIP;
|
|
/*
|
|
* We wait for the data to be transferred (8bit),
|
|
* then we start polling on the ACK/NACK bit
|
|
*/
|
|
udelay((8 * 1000) / i2c->bus_clock_khz);
|
|
}
|
|
|
|
/*
|
|
* once we are here we expect to get the expected result immediately
|
|
* so if after 1ms we timeout then something is broken.
|
|
*/
|
|
err = ocores_wait(i2c, OCI2C_STATUS, mask, 0, msecs_to_jiffies(1));
|
|
if (err)
|
|
dev_warn(i2c->adap.dev.parent,
|
|
"%s: STATUS timeout, bit 0x%x did not clear in 1ms\n",
|
|
__func__, mask);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* It handles an IRQ-less transfer
|
|
* @i2c: ocores I2C device instance
|
|
*
|
|
* Even if IRQ are disabled, the I2C OpenCore IP behavior is exactly the same
|
|
* (only that IRQ are not produced). This means that we can re-use entirely
|
|
* ocores_isr(), we just add our polling code around it.
|
|
*
|
|
* It can run in atomic context
|
|
*/
|
|
static void ocores_process_polling(struct ocores_i2c *i2c)
|
|
{
|
|
while (1) {
|
|
irqreturn_t ret;
|
|
int err;
|
|
|
|
err = ocores_poll_wait(i2c);
|
|
if (err) {
|
|
i2c->state = STATE_ERROR;
|
|
break; /* timeout */
|
|
}
|
|
|
|
ret = ocores_isr(-1, i2c);
|
|
if (ret == IRQ_NONE)
|
|
break; /* all messages have been transferred */
|
|
else {
|
|
if (i2c->flags & OCORES_FLAG_BROKEN_IRQ)
|
|
if (i2c->state == STATE_DONE)
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
static int ocores_xfer_core(struct ocores_i2c *i2c,
|
|
struct i2c_msg *msgs, int num,
|
|
bool polling)
|
|
{
|
|
int ret;
|
|
u8 ctrl;
|
|
|
|
ctrl = oc_getreg(i2c, OCI2C_CONTROL);
|
|
if (polling)
|
|
oc_setreg(i2c, OCI2C_CONTROL, ctrl & ~OCI2C_CTRL_IEN);
|
|
else
|
|
oc_setreg(i2c, OCI2C_CONTROL, ctrl | OCI2C_CTRL_IEN);
|
|
|
|
i2c->msg = msgs;
|
|
i2c->pos = 0;
|
|
i2c->nmsgs = num;
|
|
i2c->state = STATE_START;
|
|
|
|
oc_setreg(i2c, OCI2C_DATA, i2c_8bit_addr_from_msg(i2c->msg));
|
|
oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_START);
|
|
|
|
if (polling) {
|
|
ocores_process_polling(i2c);
|
|
} else {
|
|
ret = wait_event_timeout(i2c->wait,
|
|
(i2c->state == STATE_ERROR) ||
|
|
(i2c->state == STATE_DONE), HZ);
|
|
if (ret == 0) {
|
|
ocores_process_timeout(i2c);
|
|
return -ETIMEDOUT;
|
|
}
|
|
}
|
|
|
|
return (i2c->state == STATE_DONE) ? num : -EIO;
|
|
}
|
|
|
|
static int ocores_xfer_polling(struct i2c_adapter *adap,
|
|
struct i2c_msg *msgs, int num)
|
|
{
|
|
return ocores_xfer_core(i2c_get_adapdata(adap), msgs, num, true);
|
|
}
|
|
|
|
static int ocores_xfer(struct i2c_adapter *adap,
|
|
struct i2c_msg *msgs, int num)
|
|
{
|
|
return ocores_xfer_core(i2c_get_adapdata(adap), msgs, num, false);
|
|
}
|
|
|
|
static int ocores_init(struct device *dev, struct ocores_i2c *i2c)
|
|
{
|
|
int prescale;
|
|
int diff;
|
|
u8 ctrl = oc_getreg(i2c, OCI2C_CONTROL);
|
|
|
|
/* make sure the device is disabled */
|
|
ctrl &= ~(OCI2C_CTRL_EN | OCI2C_CTRL_IEN);
|
|
oc_setreg(i2c, OCI2C_CONTROL, ctrl);
|
|
|
|
prescale = (i2c->ip_clock_khz / (5 * i2c->bus_clock_khz)) - 1;
|
|
prescale = clamp(prescale, 0, 0xffff);
|
|
|
|
diff = i2c->ip_clock_khz / (5 * (prescale + 1)) - i2c->bus_clock_khz;
|
|
if (abs(diff) > i2c->bus_clock_khz / 10) {
|
|
dev_err(dev,
|
|
"Unsupported clock settings: core: %d KHz, bus: %d KHz\n",
|
|
i2c->ip_clock_khz, i2c->bus_clock_khz);
|
|
return -EINVAL;
|
|
}
|
|
|
|
oc_setreg(i2c, OCI2C_PRELOW, prescale & 0xff);
|
|
oc_setreg(i2c, OCI2C_PREHIGH, prescale >> 8);
|
|
|
|
/* Init the device */
|
|
oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_IACK);
|
|
oc_setreg(i2c, OCI2C_CONTROL, ctrl | OCI2C_CTRL_EN);
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
static u32 ocores_func(struct i2c_adapter *adap)
|
|
{
|
|
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
|
|
}
|
|
|
|
static struct i2c_algorithm ocores_algorithm = {
|
|
.master_xfer = ocores_xfer,
|
|
.master_xfer_atomic = ocores_xfer_polling,
|
|
.functionality = ocores_func,
|
|
};
|
|
|
|
static const struct i2c_adapter ocores_adapter = {
|
|
.owner = THIS_MODULE,
|
|
.name = "i2c-ocores",
|
|
.class = I2C_CLASS_DEPRECATED,
|
|
.algo = &ocores_algorithm,
|
|
};
|
|
|
|
static const struct of_device_id ocores_i2c_match[] = {
|
|
{
|
|
.compatible = "opencores,i2c-ocores",
|
|
.data = (void *)TYPE_OCORES,
|
|
},
|
|
{
|
|
.compatible = "aeroflexgaisler,i2cmst",
|
|
.data = (void *)TYPE_GRLIB,
|
|
},
|
|
{
|
|
.compatible = "sifive,fu540-c000-i2c",
|
|
},
|
|
{
|
|
.compatible = "sifive,i2c0",
|
|
},
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(of, ocores_i2c_match);
|
|
|
|
#ifdef CONFIG_OF
|
|
/*
|
|
* Read and write functions for the GRLIB port of the controller. Registers are
|
|
* 32-bit big endian and the PRELOW and PREHIGH registers are merged into one
|
|
* register. The subsequent registers have their offsets decreased accordingly.
|
|
*/
|
|
static u8 oc_getreg_grlib(struct ocores_i2c *i2c, int reg)
|
|
{
|
|
u32 rd;
|
|
int rreg = reg;
|
|
|
|
if (reg != OCI2C_PRELOW)
|
|
rreg--;
|
|
rd = ioread32be(i2c->base + (rreg << i2c->reg_shift));
|
|
if (reg == OCI2C_PREHIGH)
|
|
return (u8)(rd >> 8);
|
|
else
|
|
return (u8)rd;
|
|
}
|
|
|
|
static void oc_setreg_grlib(struct ocores_i2c *i2c, int reg, u8 value)
|
|
{
|
|
u32 curr, wr;
|
|
int rreg = reg;
|
|
|
|
if (reg != OCI2C_PRELOW)
|
|
rreg--;
|
|
if (reg == OCI2C_PRELOW || reg == OCI2C_PREHIGH) {
|
|
curr = ioread32be(i2c->base + (rreg << i2c->reg_shift));
|
|
if (reg == OCI2C_PRELOW)
|
|
wr = (curr & 0xff00) | value;
|
|
else
|
|
wr = (((u32)value) << 8) | (curr & 0xff);
|
|
} else {
|
|
wr = value;
|
|
}
|
|
iowrite32be(wr, i2c->base + (rreg << i2c->reg_shift));
|
|
}
|
|
|
|
static int ocores_i2c_of_probe(struct platform_device *pdev,
|
|
struct ocores_i2c *i2c)
|
|
{
|
|
struct device_node *np = pdev->dev.of_node;
|
|
const struct of_device_id *match;
|
|
u32 val;
|
|
u32 clock_frequency;
|
|
bool clock_frequency_present;
|
|
|
|
if (of_property_read_u32(np, "reg-shift", &i2c->reg_shift)) {
|
|
/* no 'reg-shift', check for deprecated 'regstep' */
|
|
if (!of_property_read_u32(np, "regstep", &val)) {
|
|
if (!is_power_of_2(val)) {
|
|
dev_err(&pdev->dev, "invalid regstep %d\n",
|
|
val);
|
|
return -EINVAL;
|
|
}
|
|
i2c->reg_shift = ilog2(val);
|
|
dev_warn(&pdev->dev,
|
|
"regstep property deprecated, use reg-shift\n");
|
|
}
|
|
}
|
|
|
|
clock_frequency_present = !of_property_read_u32(np, "clock-frequency",
|
|
&clock_frequency);
|
|
i2c->bus_clock_khz = 100;
|
|
|
|
i2c->clk = devm_clk_get(&pdev->dev, NULL);
|
|
|
|
if (!IS_ERR(i2c->clk)) {
|
|
int ret = clk_prepare_enable(i2c->clk);
|
|
|
|
if (ret) {
|
|
dev_err(&pdev->dev,
|
|
"clk_prepare_enable failed: %d\n", ret);
|
|
return ret;
|
|
}
|
|
i2c->ip_clock_khz = clk_get_rate(i2c->clk) / 1000;
|
|
if (clock_frequency_present)
|
|
i2c->bus_clock_khz = clock_frequency / 1000;
|
|
}
|
|
|
|
if (i2c->ip_clock_khz == 0) {
|
|
if (of_property_read_u32(np, "opencores,ip-clock-frequency",
|
|
&val)) {
|
|
if (!clock_frequency_present) {
|
|
dev_err(&pdev->dev,
|
|
"Missing required parameter 'opencores,ip-clock-frequency'\n");
|
|
clk_disable_unprepare(i2c->clk);
|
|
return -ENODEV;
|
|
}
|
|
i2c->ip_clock_khz = clock_frequency / 1000;
|
|
dev_warn(&pdev->dev,
|
|
"Deprecated usage of the 'clock-frequency' property, please update to 'opencores,ip-clock-frequency'\n");
|
|
} else {
|
|
i2c->ip_clock_khz = val / 1000;
|
|
if (clock_frequency_present)
|
|
i2c->bus_clock_khz = clock_frequency / 1000;
|
|
}
|
|
}
|
|
|
|
of_property_read_u32(pdev->dev.of_node, "reg-io-width",
|
|
&i2c->reg_io_width);
|
|
|
|
match = of_match_node(ocores_i2c_match, pdev->dev.of_node);
|
|
if (match && (long)match->data == TYPE_GRLIB) {
|
|
dev_dbg(&pdev->dev, "GRLIB variant of i2c-ocores\n");
|
|
i2c->setreg = oc_setreg_grlib;
|
|
i2c->getreg = oc_getreg_grlib;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
#else
|
|
#define ocores_i2c_of_probe(pdev, i2c) -ENODEV
|
|
#endif
|
|
|
|
static int ocores_i2c_probe(struct platform_device *pdev)
|
|
{
|
|
struct ocores_i2c *i2c;
|
|
struct ocores_i2c_platform_data *pdata;
|
|
struct resource *res;
|
|
int irq;
|
|
int ret;
|
|
int i;
|
|
|
|
i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
|
|
if (!i2c)
|
|
return -ENOMEM;
|
|
|
|
spin_lock_init(&i2c->process_lock);
|
|
|
|
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
if (res) {
|
|
i2c->base = devm_ioremap_resource(&pdev->dev, res);
|
|
if (IS_ERR(i2c->base))
|
|
return PTR_ERR(i2c->base);
|
|
} else {
|
|
res = platform_get_resource(pdev, IORESOURCE_IO, 0);
|
|
if (!res)
|
|
return -EINVAL;
|
|
i2c->iobase = res->start;
|
|
if (!devm_request_region(&pdev->dev, res->start,
|
|
resource_size(res),
|
|
pdev->name)) {
|
|
dev_err(&pdev->dev, "Can't get I/O resource.\n");
|
|
return -EBUSY;
|
|
}
|
|
i2c->setreg = oc_setreg_io_8;
|
|
i2c->getreg = oc_getreg_io_8;
|
|
}
|
|
|
|
pdata = dev_get_platdata(&pdev->dev);
|
|
if (pdata) {
|
|
i2c->reg_shift = pdata->reg_shift;
|
|
i2c->reg_io_width = pdata->reg_io_width;
|
|
i2c->ip_clock_khz = pdata->clock_khz;
|
|
if (pdata->bus_khz)
|
|
i2c->bus_clock_khz = pdata->bus_khz;
|
|
else
|
|
i2c->bus_clock_khz = 100;
|
|
} else {
|
|
ret = ocores_i2c_of_probe(pdev, i2c);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
if (i2c->reg_io_width == 0)
|
|
i2c->reg_io_width = 1; /* Set to default value */
|
|
|
|
if (!i2c->setreg || !i2c->getreg) {
|
|
bool be = pdata ? pdata->big_endian :
|
|
of_device_is_big_endian(pdev->dev.of_node);
|
|
|
|
switch (i2c->reg_io_width) {
|
|
case 1:
|
|
i2c->setreg = oc_setreg_8;
|
|
i2c->getreg = oc_getreg_8;
|
|
break;
|
|
|
|
case 2:
|
|
i2c->setreg = be ? oc_setreg_16be : oc_setreg_16;
|
|
i2c->getreg = be ? oc_getreg_16be : oc_getreg_16;
|
|
break;
|
|
|
|
case 4:
|
|
i2c->setreg = be ? oc_setreg_32be : oc_setreg_32;
|
|
i2c->getreg = be ? oc_getreg_32be : oc_getreg_32;
|
|
break;
|
|
|
|
default:
|
|
dev_err(&pdev->dev, "Unsupported I/O width (%d)\n",
|
|
i2c->reg_io_width);
|
|
ret = -EINVAL;
|
|
goto err_clk;
|
|
}
|
|
}
|
|
|
|
init_waitqueue_head(&i2c->wait);
|
|
|
|
irq = platform_get_irq_optional(pdev, 0);
|
|
/*
|
|
* Since the SoC does have an interrupt, its DT has an interrupt
|
|
* property - But this should be bypassed as the IRQ logic in this
|
|
* SoC is broken.
|
|
*/
|
|
if (of_device_is_compatible(pdev->dev.of_node,
|
|
"sifive,fu540-c000-i2c")) {
|
|
i2c->flags |= OCORES_FLAG_BROKEN_IRQ;
|
|
irq = -ENXIO;
|
|
}
|
|
|
|
if (irq == -ENXIO) {
|
|
ocores_algorithm.master_xfer = ocores_xfer_polling;
|
|
} else {
|
|
if (irq < 0)
|
|
return irq;
|
|
}
|
|
|
|
if (ocores_algorithm.master_xfer != ocores_xfer_polling) {
|
|
ret = devm_request_any_context_irq(&pdev->dev, irq,
|
|
ocores_isr, 0,
|
|
pdev->name, i2c);
|
|
if (ret) {
|
|
dev_err(&pdev->dev, "Cannot claim IRQ\n");
|
|
goto err_clk;
|
|
}
|
|
}
|
|
|
|
ret = ocores_init(&pdev->dev, i2c);
|
|
if (ret)
|
|
goto err_clk;
|
|
|
|
/* hook up driver to tree */
|
|
platform_set_drvdata(pdev, i2c);
|
|
i2c->adap = ocores_adapter;
|
|
i2c_set_adapdata(&i2c->adap, i2c);
|
|
i2c->adap.dev.parent = &pdev->dev;
|
|
i2c->adap.dev.of_node = pdev->dev.of_node;
|
|
|
|
/* add i2c adapter to i2c tree */
|
|
ret = i2c_add_adapter(&i2c->adap);
|
|
if (ret)
|
|
goto err_clk;
|
|
|
|
/* add in known devices to the bus */
|
|
if (pdata) {
|
|
for (i = 0; i < pdata->num_devices; i++)
|
|
i2c_new_client_device(&i2c->adap, pdata->devices + i);
|
|
}
|
|
|
|
return 0;
|
|
|
|
err_clk:
|
|
clk_disable_unprepare(i2c->clk);
|
|
return ret;
|
|
}
|
|
|
|
static int ocores_i2c_remove(struct platform_device *pdev)
|
|
{
|
|
struct ocores_i2c *i2c = platform_get_drvdata(pdev);
|
|
u8 ctrl = oc_getreg(i2c, OCI2C_CONTROL);
|
|
|
|
/* disable i2c logic */
|
|
ctrl &= ~(OCI2C_CTRL_EN | OCI2C_CTRL_IEN);
|
|
oc_setreg(i2c, OCI2C_CONTROL, ctrl);
|
|
|
|
/* remove adapter & data */
|
|
i2c_del_adapter(&i2c->adap);
|
|
|
|
if (!IS_ERR(i2c->clk))
|
|
clk_disable_unprepare(i2c->clk);
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_PM_SLEEP
|
|
static int ocores_i2c_suspend(struct device *dev)
|
|
{
|
|
struct ocores_i2c *i2c = dev_get_drvdata(dev);
|
|
u8 ctrl = oc_getreg(i2c, OCI2C_CONTROL);
|
|
|
|
/* make sure the device is disabled */
|
|
ctrl &= ~(OCI2C_CTRL_EN | OCI2C_CTRL_IEN);
|
|
oc_setreg(i2c, OCI2C_CONTROL, ctrl);
|
|
|
|
if (!IS_ERR(i2c->clk))
|
|
clk_disable_unprepare(i2c->clk);
|
|
return 0;
|
|
}
|
|
|
|
static int ocores_i2c_resume(struct device *dev)
|
|
{
|
|
struct ocores_i2c *i2c = dev_get_drvdata(dev);
|
|
|
|
if (!IS_ERR(i2c->clk)) {
|
|
unsigned long rate;
|
|
int ret = clk_prepare_enable(i2c->clk);
|
|
|
|
if (ret) {
|
|
dev_err(dev,
|
|
"clk_prepare_enable failed: %d\n", ret);
|
|
return ret;
|
|
}
|
|
rate = clk_get_rate(i2c->clk) / 1000;
|
|
if (rate)
|
|
i2c->ip_clock_khz = rate;
|
|
}
|
|
return ocores_init(dev, i2c);
|
|
}
|
|
|
|
static SIMPLE_DEV_PM_OPS(ocores_i2c_pm, ocores_i2c_suspend, ocores_i2c_resume);
|
|
#define OCORES_I2C_PM (&ocores_i2c_pm)
|
|
#else
|
|
#define OCORES_I2C_PM NULL
|
|
#endif
|
|
|
|
static struct platform_driver ocores_i2c_driver = {
|
|
.probe = ocores_i2c_probe,
|
|
.remove = ocores_i2c_remove,
|
|
.driver = {
|
|
.name = "ocores-i2c",
|
|
.of_match_table = ocores_i2c_match,
|
|
.pm = OCORES_I2C_PM,
|
|
},
|
|
};
|
|
|
|
module_platform_driver(ocores_i2c_driver);
|
|
|
|
MODULE_AUTHOR("Peter Korsgaard <peter@korsgaard.com>");
|
|
MODULE_DESCRIPTION("OpenCores I2C bus driver");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS("platform:ocores-i2c");
|