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Merge branch 'for-wolfram' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio into i2c/for-4.15

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Refactor i2c-gpio and its users to use gpiod. Done by GPIO maintainer
LinusW.
This commit is contained in:
Wolfram Sang
2017-11-01 23:44:52 +01:00
parent 93367bfca9 05c7477885
commit 4ee045f4e9
29 changed files with 422 additions and 288 deletions
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212
drivers/i2c/busses/i2c-gpio.c
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@@ -14,27 +14,17 @@
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/gpio.h>
#include <linux/gpio/consumer.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
struct i2c_gpio_private_data {
struct gpio_desc *sda;
struct gpio_desc *scl;
struct i2c_adapter adap;
struct i2c_algo_bit_data bit_data;
struct i2c_gpio_platform_data pdata;
};
/* Toggle SDA by changing the direction of the pin */
static void i2c_gpio_setsda_dir(void *data, int state)
{
struct i2c_gpio_platform_data *pdata = data;
if (state)
gpio_direction_input(pdata->sda_pin);
else
gpio_direction_output(pdata->sda_pin, 0);
}
/*
* Toggle SDA by changing the output value of the pin. This is only
* valid for pins configured as open drain (i.e. setting the value
@@ -42,20 +32,9 @@ static void i2c_gpio_setsda_dir(void *data, int state)
*/
static void i2c_gpio_setsda_val(void *data, int state)
{
struct i2c_gpio_platform_data *pdata = data;
struct i2c_gpio_private_data *priv = data;
gpio_set_value(pdata->sda_pin, state);
}
/* Toggle SCL by changing the direction of the pin. */
static void i2c_gpio_setscl_dir(void *data, int state)
{
struct i2c_gpio_platform_data *pdata = data;
if (state)
gpio_direction_input(pdata->scl_pin);
else
gpio_direction_output(pdata->scl_pin, 0);
gpiod_set_value(priv->sda, state);
}
/*
@@ -66,44 +45,23 @@ static void i2c_gpio_setscl_dir(void *data, int state)
*/
static void i2c_gpio_setscl_val(void *data, int state)
{
struct i2c_gpio_platform_data *pdata = data;
struct i2c_gpio_private_data *priv = data;
gpio_set_value(pdata->scl_pin, state);
gpiod_set_value(priv->scl, state);
}
static int i2c_gpio_getsda(void *data)
{
struct i2c_gpio_platform_data *pdata = data;
struct i2c_gpio_private_data *priv = data;
return gpio_get_value(pdata->sda_pin);
return gpiod_get_value(priv->sda);
}
static int i2c_gpio_getscl(void *data)
{
struct i2c_gpio_platform_data *pdata = data;
struct i2c_gpio_private_data *priv = data;
return gpio_get_value(pdata->scl_pin);
}
static int of_i2c_gpio_get_pins(struct device_node *np,
unsigned int *sda_pin, unsigned int *scl_pin)
{
if (of_gpio_count(np) < 2)
return -ENODEV;
*sda_pin = of_get_gpio(np, 0);
*scl_pin = of_get_gpio(np, 1);
if (*sda_pin == -EPROBE_DEFER || *scl_pin == -EPROBE_DEFER)
return -EPROBE_DEFER;
if (!gpio_is_valid(*sda_pin) || !gpio_is_valid(*scl_pin)) {
pr_err("%pOF: invalid GPIO pins, sda=%d/scl=%d\n",
np, *sda_pin, *scl_pin);
return -ENODEV;
}
return 0;
return gpiod_get_value(priv->scl);
}
static void of_i2c_gpio_get_props(struct device_node *np,
@@ -124,72 +82,105 @@ static void of_i2c_gpio_get_props(struct device_node *np,
of_property_read_bool(np, "i2c-gpio,scl-output-only");
}
static struct gpio_desc *i2c_gpio_get_desc(struct device *dev,
const char *con_id,
unsigned int index,
enum gpiod_flags gflags)
{
struct gpio_desc *retdesc;
int ret;
retdesc = devm_gpiod_get(dev, con_id, gflags);
if (!IS_ERR(retdesc)) {
dev_dbg(dev, "got GPIO from name %s\n", con_id);
return retdesc;
}
retdesc = devm_gpiod_get_index(dev, NULL, index, gflags);
if (!IS_ERR(retdesc)) {
dev_dbg(dev, "got GPIO from index %u\n", index);
return retdesc;
}
ret = PTR_ERR(retdesc);
/* FIXME: hack in the old code, is this really necessary? */
if (ret == -EINVAL)
retdesc = ERR_PTR(-EPROBE_DEFER);
/* This happens if the GPIO driver is not yet probed, let's defer */
if (ret == -ENOENT)
retdesc = ERR_PTR(-EPROBE_DEFER);
if (ret != -EPROBE_DEFER)
dev_err(dev, "error trying to get descriptor: %d\n", ret);
return retdesc;
}
static int i2c_gpio_probe(struct platform_device *pdev)
{
struct i2c_gpio_private_data *priv;
struct i2c_gpio_platform_data *pdata;
struct i2c_algo_bit_data *bit_data;
struct i2c_adapter *adap;
unsigned int sda_pin, scl_pin;
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
enum gpiod_flags gflags;
int ret;
/* First get the GPIO pins; if it fails, we'll defer the probe. */
if (pdev->dev.of_node) {
ret = of_i2c_gpio_get_pins(pdev->dev.of_node,
&sda_pin, &scl_pin);
if (ret)
return ret;
} else {
if (!dev_get_platdata(&pdev->dev))
return -ENXIO;
pdata = dev_get_platdata(&pdev->dev);
sda_pin = pdata->sda_pin;
scl_pin = pdata->scl_pin;
}
ret = devm_gpio_request(&pdev->dev, sda_pin, "sda");
if (ret) {
if (ret == -EINVAL)
ret = -EPROBE_DEFER; /* Try again later */
return ret;
}
ret = devm_gpio_request(&pdev->dev, scl_pin, "scl");
if (ret) {
if (ret == -EINVAL)
ret = -EPROBE_DEFER; /* Try again later */
return ret;
}
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
adap = &priv->adap;
bit_data = &priv->bit_data;
pdata = &priv->pdata;
if (pdev->dev.of_node) {
pdata->sda_pin = sda_pin;
pdata->scl_pin = scl_pin;
of_i2c_gpio_get_props(pdev->dev.of_node, pdata);
if (np) {
of_i2c_gpio_get_props(np, pdata);
} else {
memcpy(pdata, dev_get_platdata(&pdev->dev), sizeof(*pdata));
/*
* If all platform data settings are zero it is OK
* to not provide any platform data from the board.
*/
if (dev_get_platdata(dev))
memcpy(pdata, dev_get_platdata(dev), sizeof(*pdata));
}
if (pdata->sda_is_open_drain) {
gpio_direction_output(pdata->sda_pin, 1);
bit_data->setsda = i2c_gpio_setsda_val;
} else {
gpio_direction_input(pdata->sda_pin);
bit_data->setsda = i2c_gpio_setsda_dir;
}
/*
* First get the GPIO pins; if it fails, we'll defer the probe.
* If the SDA line is marked from platform data or device tree as
* "open drain" it means something outside of our control is making
* this line being handled as open drain, and we should just handle
* it as any other output. Else we enforce open drain as this is
* required for an I2C bus.
*/
if (pdata->sda_is_open_drain)
gflags = GPIOD_OUT_HIGH;
else
gflags = GPIOD_OUT_HIGH_OPEN_DRAIN;
priv->sda = i2c_gpio_get_desc(dev, "sda", 0, gflags);
if (IS_ERR(priv->sda))
return PTR_ERR(priv->sda);
if (pdata->scl_is_open_drain || pdata->scl_is_output_only) {
gpio_direction_output(pdata->scl_pin, 1);
bit_data->setscl = i2c_gpio_setscl_val;
} else {
gpio_direction_input(pdata->scl_pin);
bit_data->setscl = i2c_gpio_setscl_dir;
}
/*
* If the SCL line is marked from platform data or device tree as
* "open drain" it means something outside of our control is making
* this line being handled as open drain, and we should just handle
* it as any other output. Else we enforce open drain as this is
* required for an I2C bus.
*/
if (pdata->scl_is_open_drain)
gflags = GPIOD_OUT_LOW;
else
gflags = GPIOD_OUT_LOW_OPEN_DRAIN;
priv->scl = i2c_gpio_get_desc(dev, "scl", 1, gflags);
if (IS_ERR(priv->scl))
return PTR_ERR(priv->scl);
bit_data->setsda = i2c_gpio_setsda_val;
bit_data->setscl = i2c_gpio_setscl_val;
if (!pdata->scl_is_output_only)
bit_data->getscl = i2c_gpio_getscl;
@@ -207,18 +198,18 @@ static int i2c_gpio_probe(struct platform_device *pdev)
else
bit_data->timeout = HZ / 10; /* 100 ms */
bit_data->data = pdata;
bit_data->data = priv;
adap->owner = THIS_MODULE;
if (pdev->dev.of_node)
strlcpy(adap->name, dev_name(&pdev->dev), sizeof(adap->name));
if (np)
strlcpy(adap->name, dev_name(dev), sizeof(adap->name));
else
snprintf(adap->name, sizeof(adap->name), "i2c-gpio%d", pdev->id);
adap->algo_data = bit_data;
adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
adap->dev.parent = &pdev->dev;
adap->dev.of_node = pdev->dev.of_node;
adap->dev.parent = dev;
adap->dev.of_node = np;
adap->nr = pdev->id;
ret = i2c_bit_add_numbered_bus(adap);
@@ -227,8 +218,13 @@ static int i2c_gpio_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, priv);
dev_info(&pdev->dev, "using pins %u (SDA) and %u (SCL%s)\n",
pdata->sda_pin, pdata->scl_pin,
/*
* FIXME: using global GPIO numbers is not helpful. If/when we
* get accessors to get the actual name of the GPIO line,
* from the descriptor, then provide that instead.
*/
dev_info(dev, "using lines %u (SDA) and %u (SCL%s)\n",
desc_to_gpio(priv->sda), desc_to_gpio(priv->scl),
pdata->scl_is_output_only
? ", no clock stretching" : "");