mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 10:49:33 +00:00
![Thomas Gleixner](/assets/img/avatar_default.png)
Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
382 lines
8 KiB
C
382 lines
8 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* I2C bus driver for Conexant Digicolor SoCs
|
|
*
|
|
* Author: Baruch Siach <baruch@tkos.co.il>
|
|
*
|
|
* Copyright (C) 2015 Paradox Innovation Ltd.
|
|
*/
|
|
|
|
#include <linux/clk.h>
|
|
#include <linux/completion.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/i2c.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/io.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/of.h>
|
|
#include <linux/platform_device.h>
|
|
|
|
#define DEFAULT_FREQ 100000
|
|
#define TIMEOUT_MS 100
|
|
|
|
#define II_CONTROL 0x0
|
|
#define II_CONTROL_LOCAL_RESET BIT(0)
|
|
|
|
#define II_CLOCKTIME 0x1
|
|
|
|
#define II_COMMAND 0x2
|
|
#define II_CMD_START 1
|
|
#define II_CMD_RESTART 2
|
|
#define II_CMD_SEND_ACK 3
|
|
#define II_CMD_GET_ACK 6
|
|
#define II_CMD_GET_NOACK 7
|
|
#define II_CMD_STOP 10
|
|
#define II_COMMAND_GO BIT(7)
|
|
#define II_COMMAND_COMPLETION_STATUS(r) (((r) >> 5) & 3)
|
|
#define II_CMD_STATUS_NORMAL 0
|
|
#define II_CMD_STATUS_ACK_GOOD 1
|
|
#define II_CMD_STATUS_ACK_BAD 2
|
|
#define II_CMD_STATUS_ABORT 3
|
|
|
|
#define II_DATA 0x3
|
|
#define II_INTFLAG_CLEAR 0x8
|
|
#define II_INTENABLE 0xa
|
|
|
|
struct dc_i2c {
|
|
struct i2c_adapter adap;
|
|
struct device *dev;
|
|
void __iomem *regs;
|
|
struct clk *clk;
|
|
unsigned int frequency;
|
|
|
|
struct i2c_msg *msg;
|
|
unsigned int msgbuf_ptr;
|
|
int last;
|
|
spinlock_t lock;
|
|
struct completion done;
|
|
int state;
|
|
int error;
|
|
};
|
|
|
|
enum {
|
|
STATE_IDLE,
|
|
STATE_START,
|
|
STATE_ADDR,
|
|
STATE_WRITE,
|
|
STATE_READ,
|
|
STATE_STOP,
|
|
};
|
|
|
|
static void dc_i2c_cmd(struct dc_i2c *i2c, u8 cmd)
|
|
{
|
|
writeb_relaxed(cmd | II_COMMAND_GO, i2c->regs + II_COMMAND);
|
|
}
|
|
|
|
static u8 dc_i2c_addr_cmd(struct i2c_msg *msg)
|
|
{
|
|
u8 addr = (msg->addr & 0x7f) << 1;
|
|
|
|
if (msg->flags & I2C_M_RD)
|
|
addr |= 1;
|
|
|
|
return addr;
|
|
}
|
|
|
|
static void dc_i2c_data(struct dc_i2c *i2c, u8 data)
|
|
{
|
|
writeb_relaxed(data, i2c->regs + II_DATA);
|
|
}
|
|
|
|
static void dc_i2c_write_byte(struct dc_i2c *i2c, u8 byte)
|
|
{
|
|
dc_i2c_data(i2c, byte);
|
|
dc_i2c_cmd(i2c, II_CMD_SEND_ACK);
|
|
}
|
|
|
|
static void dc_i2c_write_buf(struct dc_i2c *i2c)
|
|
{
|
|
dc_i2c_write_byte(i2c, i2c->msg->buf[i2c->msgbuf_ptr++]);
|
|
}
|
|
|
|
static void dc_i2c_next_read(struct dc_i2c *i2c)
|
|
{
|
|
bool last = (i2c->msgbuf_ptr + 1 == i2c->msg->len);
|
|
|
|
dc_i2c_cmd(i2c, last ? II_CMD_GET_NOACK : II_CMD_GET_ACK);
|
|
}
|
|
|
|
static void dc_i2c_stop(struct dc_i2c *i2c)
|
|
{
|
|
i2c->state = STATE_STOP;
|
|
if (i2c->last)
|
|
dc_i2c_cmd(i2c, II_CMD_STOP);
|
|
else
|
|
complete(&i2c->done);
|
|
}
|
|
|
|
static u8 dc_i2c_read_byte(struct dc_i2c *i2c)
|
|
{
|
|
return readb_relaxed(i2c->regs + II_DATA);
|
|
}
|
|
|
|
static void dc_i2c_read_buf(struct dc_i2c *i2c)
|
|
{
|
|
i2c->msg->buf[i2c->msgbuf_ptr++] = dc_i2c_read_byte(i2c);
|
|
dc_i2c_next_read(i2c);
|
|
}
|
|
|
|
static void dc_i2c_set_irq(struct dc_i2c *i2c, int enable)
|
|
{
|
|
if (enable)
|
|
writeb_relaxed(1, i2c->regs + II_INTFLAG_CLEAR);
|
|
writeb_relaxed(!!enable, i2c->regs + II_INTENABLE);
|
|
}
|
|
|
|
static int dc_i2c_cmd_status(struct dc_i2c *i2c)
|
|
{
|
|
u8 cmd = readb_relaxed(i2c->regs + II_COMMAND);
|
|
|
|
return II_COMMAND_COMPLETION_STATUS(cmd);
|
|
}
|
|
|
|
static void dc_i2c_start_msg(struct dc_i2c *i2c, int first)
|
|
{
|
|
struct i2c_msg *msg = i2c->msg;
|
|
|
|
if (!(msg->flags & I2C_M_NOSTART)) {
|
|
i2c->state = STATE_START;
|
|
dc_i2c_cmd(i2c, first ? II_CMD_START : II_CMD_RESTART);
|
|
} else if (msg->flags & I2C_M_RD) {
|
|
i2c->state = STATE_READ;
|
|
dc_i2c_next_read(i2c);
|
|
} else {
|
|
i2c->state = STATE_WRITE;
|
|
dc_i2c_write_buf(i2c);
|
|
}
|
|
}
|
|
|
|
static irqreturn_t dc_i2c_irq(int irq, void *dev_id)
|
|
{
|
|
struct dc_i2c *i2c = dev_id;
|
|
int cmd_status = dc_i2c_cmd_status(i2c);
|
|
unsigned long flags;
|
|
u8 addr_cmd;
|
|
|
|
writeb_relaxed(1, i2c->regs + II_INTFLAG_CLEAR);
|
|
|
|
spin_lock_irqsave(&i2c->lock, flags);
|
|
|
|
if (cmd_status == II_CMD_STATUS_ACK_BAD
|
|
|| cmd_status == II_CMD_STATUS_ABORT) {
|
|
i2c->error = -EIO;
|
|
complete(&i2c->done);
|
|
goto out;
|
|
}
|
|
|
|
switch (i2c->state) {
|
|
case STATE_START:
|
|
addr_cmd = dc_i2c_addr_cmd(i2c->msg);
|
|
dc_i2c_write_byte(i2c, addr_cmd);
|
|
i2c->state = STATE_ADDR;
|
|
break;
|
|
case STATE_ADDR:
|
|
if (i2c->msg->flags & I2C_M_RD) {
|
|
dc_i2c_next_read(i2c);
|
|
i2c->state = STATE_READ;
|
|
break;
|
|
}
|
|
i2c->state = STATE_WRITE;
|
|
/* fall through */
|
|
case STATE_WRITE:
|
|
if (i2c->msgbuf_ptr < i2c->msg->len)
|
|
dc_i2c_write_buf(i2c);
|
|
else
|
|
dc_i2c_stop(i2c);
|
|
break;
|
|
case STATE_READ:
|
|
if (i2c->msgbuf_ptr < i2c->msg->len)
|
|
dc_i2c_read_buf(i2c);
|
|
else
|
|
dc_i2c_stop(i2c);
|
|
break;
|
|
case STATE_STOP:
|
|
i2c->state = STATE_IDLE;
|
|
complete(&i2c->done);
|
|
break;
|
|
}
|
|
|
|
out:
|
|
spin_unlock_irqrestore(&i2c->lock, flags);
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static int dc_i2c_xfer_msg(struct dc_i2c *i2c, struct i2c_msg *msg, int first,
|
|
int last)
|
|
{
|
|
unsigned long timeout = msecs_to_jiffies(TIMEOUT_MS);
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&i2c->lock, flags);
|
|
i2c->msg = msg;
|
|
i2c->msgbuf_ptr = 0;
|
|
i2c->last = last;
|
|
i2c->error = 0;
|
|
|
|
reinit_completion(&i2c->done);
|
|
dc_i2c_set_irq(i2c, 1);
|
|
dc_i2c_start_msg(i2c, first);
|
|
spin_unlock_irqrestore(&i2c->lock, flags);
|
|
|
|
timeout = wait_for_completion_timeout(&i2c->done, timeout);
|
|
dc_i2c_set_irq(i2c, 0);
|
|
if (timeout == 0) {
|
|
i2c->state = STATE_IDLE;
|
|
return -ETIMEDOUT;
|
|
}
|
|
|
|
if (i2c->error)
|
|
return i2c->error;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int dc_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
|
|
{
|
|
struct dc_i2c *i2c = adap->algo_data;
|
|
int i, ret;
|
|
|
|
for (i = 0; i < num; i++) {
|
|
ret = dc_i2c_xfer_msg(i2c, &msgs[i], i == 0, i == num - 1);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
return num;
|
|
}
|
|
|
|
static int dc_i2c_init_hw(struct dc_i2c *i2c)
|
|
{
|
|
unsigned long clk_rate = clk_get_rate(i2c->clk);
|
|
unsigned int clocktime;
|
|
|
|
writeb_relaxed(II_CONTROL_LOCAL_RESET, i2c->regs + II_CONTROL);
|
|
udelay(100);
|
|
writeb_relaxed(0, i2c->regs + II_CONTROL);
|
|
udelay(100);
|
|
|
|
clocktime = DIV_ROUND_UP(clk_rate, 64 * i2c->frequency);
|
|
if (clocktime < 1 || clocktime > 0xff) {
|
|
dev_err(i2c->dev, "can't set bus speed of %u Hz\n",
|
|
i2c->frequency);
|
|
return -EINVAL;
|
|
}
|
|
writeb_relaxed(clocktime - 1, i2c->regs + II_CLOCKTIME);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static u32 dc_i2c_func(struct i2c_adapter *adap)
|
|
{
|
|
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_NOSTART;
|
|
}
|
|
|
|
static const struct i2c_algorithm dc_i2c_algorithm = {
|
|
.master_xfer = dc_i2c_xfer,
|
|
.functionality = dc_i2c_func,
|
|
};
|
|
|
|
static int dc_i2c_probe(struct platform_device *pdev)
|
|
{
|
|
struct device_node *np = pdev->dev.of_node;
|
|
struct dc_i2c *i2c;
|
|
struct resource *r;
|
|
int ret = 0, irq;
|
|
|
|
i2c = devm_kzalloc(&pdev->dev, sizeof(struct dc_i2c), GFP_KERNEL);
|
|
if (!i2c)
|
|
return -ENOMEM;
|
|
|
|
if (of_property_read_u32(pdev->dev.of_node, "clock-frequency",
|
|
&i2c->frequency))
|
|
i2c->frequency = DEFAULT_FREQ;
|
|
|
|
i2c->dev = &pdev->dev;
|
|
platform_set_drvdata(pdev, i2c);
|
|
|
|
spin_lock_init(&i2c->lock);
|
|
init_completion(&i2c->done);
|
|
|
|
i2c->clk = devm_clk_get(&pdev->dev, NULL);
|
|
if (IS_ERR(i2c->clk))
|
|
return PTR_ERR(i2c->clk);
|
|
|
|
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
i2c->regs = devm_ioremap_resource(&pdev->dev, r);
|
|
if (IS_ERR(i2c->regs))
|
|
return PTR_ERR(i2c->regs);
|
|
|
|
irq = platform_get_irq(pdev, 0);
|
|
if (irq < 0)
|
|
return irq;
|
|
|
|
ret = devm_request_irq(&pdev->dev, irq, dc_i2c_irq, 0,
|
|
dev_name(&pdev->dev), i2c);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
strlcpy(i2c->adap.name, "Conexant Digicolor I2C adapter",
|
|
sizeof(i2c->adap.name));
|
|
i2c->adap.owner = THIS_MODULE;
|
|
i2c->adap.algo = &dc_i2c_algorithm;
|
|
i2c->adap.dev.parent = &pdev->dev;
|
|
i2c->adap.dev.of_node = np;
|
|
i2c->adap.algo_data = i2c;
|
|
|
|
ret = dc_i2c_init_hw(i2c);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = clk_prepare_enable(i2c->clk);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
ret = i2c_add_adapter(&i2c->adap);
|
|
if (ret < 0) {
|
|
clk_disable_unprepare(i2c->clk);
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int dc_i2c_remove(struct platform_device *pdev)
|
|
{
|
|
struct dc_i2c *i2c = platform_get_drvdata(pdev);
|
|
|
|
i2c_del_adapter(&i2c->adap);
|
|
clk_disable_unprepare(i2c->clk);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct of_device_id dc_i2c_match[] = {
|
|
{ .compatible = "cnxt,cx92755-i2c" },
|
|
{ },
|
|
};
|
|
MODULE_DEVICE_TABLE(of, dc_i2c_match);
|
|
|
|
static struct platform_driver dc_i2c_driver = {
|
|
.probe = dc_i2c_probe,
|
|
.remove = dc_i2c_remove,
|
|
.driver = {
|
|
.name = "digicolor-i2c",
|
|
.of_match_table = dc_i2c_match,
|
|
},
|
|
};
|
|
module_platform_driver(dc_i2c_driver);
|
|
|
|
MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
|
|
MODULE_DESCRIPTION("Conexant Digicolor I2C master driver");
|
|
MODULE_LICENSE("GPL v2");
|