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ODROID-M1: driver/i2c: Add driver "speed" attribution

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for change i2c bus freq dynamically.

e.g.
  $ echo 400000 | sudo tee /sys/bus/i2c/devices/i2c-0/device/speed

Signed-off-by: Steve Jeong <how2soft@gmail.com>
Change-Id: Ifcccf9bb61ed65133b64c803b53fb4e46d470e26
This commit is contained in:
Steve Jeong
2023-04-07 12:03:14 +09:00
committed by codewalkerster
parent 20c1d4acf2
commit c82036b6da
1 changed files with 32 additions and 0 deletions
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32
drivers/i2c/busses/i2c-rk3x.c
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@@ -1897,6 +1897,32 @@ static void rk3x_i2c_tb_cb(void *data)
enable_irq(i2c->irq);
}
static ssize_t rk3x_i2c_speed_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct rk3x_i2c *i2c = dev_get_drvdata(dev);
struct i2c_timings *t = &i2c->t;
return snprintf(buf, PAGE_SIZE, "%u\n", t->bus_freq_hz);
}
static ssize_t rk3x_i2c_speed_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
struct rk3x_i2c *i2c = dev_get_drvdata(dev);
struct i2c_timings *t = &i2c->t;
int ret, freq;
ret = kstrtoint(buf, 10, &freq);
if (ret < 0)
return ret;
t->bus_freq_hz = (uint32_t)freq;
rk3x_i2c_adapt_div(i2c, clk_get_rate(i2c->clk));
return count;
}
static DEVICE_ATTR(speed, S_IRUGO | S_IWUSR, rk3x_i2c_speed_show, rk3x_i2c_speed_store);
static int rk3x_i2c_probe(struct platform_device *pdev)
{
struct fwnode_handle *fw = dev_fwnode(&pdev->dev);
@@ -1911,6 +1937,11 @@ static int rk3x_i2c_probe(struct platform_device *pdev)
if (!i2c)
return -ENOMEM;
ret = device_create_file(&pdev->dev, &dev_attr_speed);
if (ret < 0) {
dev_err(&pdev->dev, "Failed to create speed attribute file: %d\n", ret);
}
i2c->soc_data = (struct rk3x_i2c_soc_data *)device_get_match_data(&pdev->dev);
ret = rk3x_i2c_acpi_get_bus_id(&pdev->dev, i2c);
@@ -2097,6 +2128,7 @@ static int rk3x_i2c_remove(struct platform_device *pdev)
if (i2c->soc_data->dma_control)
i2c->soc_data->dma_control(pdev, false);
device_remove_file(&pdev->dev, &dev_attr_speed);
unregister_restart_handler(&i2c->i2c_restart_nb);
clk_notifier_unregister(i2c->clk, &i2c->clk_rate_nb);
clk_unprepare(i2c->pclk);