[PATCH 4/5] W1: w1-gpio - rework handling of platform data

From: Dmitry Torokhov
Date: Sat Feb 23 2013 - 02:59:22 EST


The platform data in the dveice structure does not belong to the driver
and so it should not be trying to alter it, but instead use a local pointer
and populate it with a local copy in case we are dealing with device tree
setup.

Also allow mixed setups where platform data coexists with device tree and
prefer kernel-supplied data (it may be easier to fiddle in kernel structure
before committing final result to device tree).

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
---
drivers/w1/masters/w1-gpio.c | 93 +++++++++++++++++++++++++-------------------
1 file changed, 53 insertions(+), 40 deletions(-)

diff --git a/drivers/w1/masters/w1-gpio.c b/drivers/w1/masters/w1-gpio.c
index aa97a96..ee6b6e3 100644
--- a/drivers/w1/masters/w1-gpio.c
+++ b/drivers/w1/masters/w1-gpio.c
@@ -23,28 +23,33 @@
#include "../w1.h"
#include "../w1_int.h"

+struct w1_gpio {
+ struct w1_bus_master master;
+ const struct w1_gpio_platform_data *pdata;
+};
+
static void w1_gpio_write_bit_dir(void *data, u8 bit)
{
- struct w1_gpio_platform_data *pdata = data;
+ struct w1_gpio *w1_gpio = data;

if (bit)
- gpio_direction_input(pdata->pin);
+ gpio_direction_input(w1_gpio->pdata->pin);
else
- gpio_direction_output(pdata->pin, 0);
+ gpio_direction_output(w1_gpio->pdata->pin, 0);
}

static void w1_gpio_write_bit_val(void *data, u8 bit)
{
- struct w1_gpio_platform_data *pdata = data;
+ struct w1_gpio *w1_gpio = data;

- gpio_set_value(pdata->pin, bit);
+ gpio_set_value(w1_gpio->pdata->pin, bit);
}

static u8 w1_gpio_read_bit(void *data)
{
- struct w1_gpio_platform_data *pdata = data;
+ struct w1_gpio *w1_gpio = data;

- return gpio_get_value(pdata->pin) ? 1 : 0;
+ return gpio_get_value(w1_gpio->pdata->pin) ? 1 : 0;
}

#ifdef CONFIG_OF
@@ -55,38 +60,43 @@ static struct of_device_id w1_gpio_dt_ids[] = {
};
MODULE_DEVICE_TABLE(of, w1_gpio_dt_ids);

-static int w1_gpio_probe_dt(struct platform_device *pdev)
+static struct w1_gpio_platform_data *
+w1_gpio_probe_dt(struct platform_device *pdev)
{
- struct w1_gpio_platform_data *pdata = pdev->dev.platform_data;
+ struct w1_gpio_platform_data *pdata;
struct device_node *np = pdev->dev.of_node;

+ if (!np)
+ return ERR_PTR(-ENOENT);
+
pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
if (!pdata)
- return -ENOMEM;
+ return ERR_PTR(-ENOMEM);

if (of_get_property(np, "linux,open-drain", NULL))
pdata->is_open_drain = 1;

pdata->pin = of_get_gpio(np, 0);
pdata->ext_pullup_enable_pin = of_get_gpio(np, 1);
- pdev->dev.platform_data = pdata;

- return 0;
+ return pdata;
}

#else

-static inline int w1_gpio_probe_dt(struct platform_device *pdev)
+static inline struct w1_gpio_platform_data *
+w1_gpio_probe_dt(struct platform_device *pdev)
{
- return -ENOSYS;
+ return NULL;
}

#endif

static int w1_gpio_probe(struct platform_device *pdev)
{
- struct w1_bus_master *master;
- struct w1_gpio_platform_data *pdata;
+ const struct w1_gpio_platform_data *pdata =
+ dev_get_platdata(&pdev->dev);
+ struct w1_gpio *w1_gpio;
struct pinctrl *pinctrl;
int err;

@@ -94,23 +104,20 @@ static int w1_gpio_probe(struct platform_device *pdev)
if (IS_ERR(pinctrl))
dev_warn(&pdev->dev, "unable to select pin group\n");

- if (of_have_populated_dt()) {
- err = w1_gpio_probe_dt(pdev);
- if (err < 0) {
- dev_err(&pdev->dev, "Failed to parse DT\n");
- return err;
- }
- }
-
- pdata = pdev->dev.platform_data;
+ if (!pdata)
+ pdata = w1_gpio_probe_dt(pdev);

if (!pdata) {
dev_err(&pdev->dev, "No configuration data\n");
return -ENXIO;
+ } else if (IS_ERR(pdata)) {
+ err = PTR_ERR(pdata);
+ dev_err(&pdev->dev, "Failed to parse DT\n");
+ return err;
}

- master = kzalloc(sizeof(struct w1_bus_master), GFP_KERNEL);
- if (!master) {
+ w1_gpio = kzalloc(sizeof(struct w1_gpio), GFP_KERNEL);
+ if (!w1_gpio) {
dev_err(&pdev->dev, "Out of memory\n");
return -ENOMEM;
}
@@ -131,18 +138,20 @@ static int w1_gpio_probe(struct platform_device *pdev)
}
}

- master->data = pdata;
- master->read_bit = w1_gpio_read_bit;
+ w1_gpio->pdata = pdata;
+
+ w1_gpio->master.data = w1_gpio;
+ w1_gpio->master.read_bit = w1_gpio_read_bit;

if (pdata->is_open_drain) {
gpio_direction_output(pdata->pin, 1);
- master->write_bit = w1_gpio_write_bit_val;
+ w1_gpio->master.write_bit = w1_gpio_write_bit_val;
} else {
gpio_direction_input(pdata->pin);
- master->write_bit = w1_gpio_write_bit_dir;
+ w1_gpio->master.write_bit = w1_gpio_write_bit_dir;
}

- err = w1_add_master_device(master);
+ err = w1_add_master_device(&w1_gpio->master);
if (err) {
dev_err(&pdev->dev, "w1_add_master device failed\n");
goto free_gpio_ext_pu;
@@ -154,7 +163,7 @@ static int w1_gpio_probe(struct platform_device *pdev)
if (gpio_is_valid(pdata->ext_pullup_enable_pin))
gpio_set_value(pdata->ext_pullup_enable_pin, 1);

- platform_set_drvdata(pdev, master);
+ platform_set_drvdata(pdev, w1_gpio);

return 0;

@@ -164,15 +173,15 @@ static int w1_gpio_probe(struct platform_device *pdev)
free_gpio:
gpio_free(pdata->pin);
free_master:
- kfree(master);
+ kfree(w1_gpio);

return err;
}

static int w1_gpio_remove(struct platform_device *pdev)
{
- struct w1_bus_master *master = platform_get_drvdata(pdev);
- struct w1_gpio_platform_data *pdata = pdev->dev.platform_data;
+ struct w1_gpio *w1_gpio = platform_get_drvdata(pdev);
+ const struct w1_gpio_platform_data *pdata = w1_gpio->pdata;

if (pdata->enable_external_pullup)
pdata->enable_external_pullup(0);
@@ -180,9 +189,9 @@ static int w1_gpio_remove(struct platform_device *pdev)
if (gpio_is_valid(pdata->ext_pullup_enable_pin))
gpio_set_value(pdata->ext_pullup_enable_pin, 0);

- w1_remove_master_device(master);
+ w1_remove_master_device(&w1_gpio->master);
gpio_free(pdata->pin);
- kfree(master);
+ kfree(w1_gpio);

return 0;
}
@@ -190,7 +199,9 @@ static int w1_gpio_remove(struct platform_device *pdev)
#ifdef CONFIG_PM_SLEEP
static int w1_gpio_suspend(struct device *dev)
{
- const struct w1_gpio_platform_data *pdata = dev_get_platdata(dev);
+ struct platform_device *pdev = to_platform_device(dev);
+ struct w1_gpio *w1_gpio = platform_get_drvdata(pdev);
+ const struct w1_gpio_platform_data *pdata = w1_gpio->pdata;

if (pdata->enable_external_pullup)
pdata->enable_external_pullup(0);
@@ -200,7 +211,9 @@ static int w1_gpio_suspend(struct device *dev)

static int w1_gpio_resume(struct device *dev)
{
- const struct w1_gpio_platform_data *pdata = dev_get_platdata(dev);
+ struct platform_device *pdev = to_platform_device(dev);
+ struct w1_gpio *w1_gpio = platform_get_drvdata(pdev);
+ const struct w1_gpio_platform_data *pdata = w1_gpio->pdata;

if (pdata->enable_external_pullup)
pdata->enable_external_pullup(1);
--
1.7.11.7

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