[PATCH v2 1/7] gpio: mockup: readability tweaks

From: Bartosz Golaszewski
Date: Mon Feb 06 2017 - 07:12:07 EST


The following patch tries to improve the readability of the mockup
driver.

The driver is called gpio-mockup, so add the same prefix to all
functions and structures.

Add some newlines and use a temporary pointer in gpio_mockup_add().

Drop the name of the direction enum and rename the enum values to
better reflect their purpose.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
---
drivers/gpio/gpio-mockup.c | 123 ++++++++++++++++++++++++---------------------
1 file changed, 66 insertions(+), 57 deletions(-)

diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c
index 82a9efd..5f6ed4b 100644
--- a/drivers/gpio/gpio-mockup.c
+++ b/drivers/gpio/gpio-mockup.c
@@ -16,12 +16,12 @@
#include <linux/gpio/driver.h>
#include <linux/platform_device.h>

-#define GPIO_NAME "gpio-mockup"
-#define MAX_GC 10
+#define GPIO_MOCKUP_NAME "gpio-mockup"
+#define GPIO_MOCKUP_MAX_GC 10

-enum direction {
- OUT,
- IN
+enum {
+ DIR_IN = 0,
+ DIR_OUT,
};

/*
@@ -29,98 +29,104 @@ enum direction {
* @dir: Configures direction of gpio as "in" or "out", 0=in, 1=out
* @value: Configures status of the gpio as 0(low) or 1(high)
*/
-struct gpio_pin_status {
- enum direction dir;
+struct gpio_mockup_line_status {
+ int dir;
bool value;
};

-struct mockup_gpio_controller {
+struct gpio_mockup_chip {
struct gpio_chip gc;
- struct gpio_pin_status *stats;
+ struct gpio_mockup_line_status *lines;
};

-static int gpio_mockup_ranges[MAX_GC << 1];
+static int gpio_mockup_ranges[GPIO_MOCKUP_MAX_GC << 1];
static int gpio_mockup_params_nr;
module_param_array(gpio_mockup_ranges, int, &gpio_mockup_params_nr, 0400);

-static const char pins_name_start = 'A';
+static const char gpio_mockup_name_start = 'A';

-static int mockup_gpio_get(struct gpio_chip *gc, unsigned int offset)
+static int gpio_mockup_get(struct gpio_chip *gc, unsigned int offset)
{
- struct mockup_gpio_controller *cntr = gpiochip_get_data(gc);
+ struct gpio_mockup_chip *chip = gpiochip_get_data(gc);

- return cntr->stats[offset].value;
+ return chip->lines[offset].value;
}

-static void mockup_gpio_set(struct gpio_chip *gc, unsigned int offset,
+static void gpio_mockup_set(struct gpio_chip *gc, unsigned int offset,
int value)
{
- struct mockup_gpio_controller *cntr = gpiochip_get_data(gc);
+ struct gpio_mockup_chip *chip = gpiochip_get_data(gc);

- cntr->stats[offset].value = !!value;
+ chip->lines[offset].value = !!value;
}

-static int mockup_gpio_dirout(struct gpio_chip *gc, unsigned int offset,
+static int gpio_mockup_dirout(struct gpio_chip *gc, unsigned int offset,
int value)
{
- struct mockup_gpio_controller *cntr = gpiochip_get_data(gc);
+ struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
+
+ gpio_mockup_set(gc, offset, value);
+ chip->lines[offset].dir = DIR_OUT;

- mockup_gpio_set(gc, offset, value);
- cntr->stats[offset].dir = OUT;
return 0;
}

-static int mockup_gpio_dirin(struct gpio_chip *gc, unsigned int offset)
+static int gpio_mockup_dirin(struct gpio_chip *gc, unsigned int offset)
{
- struct mockup_gpio_controller *cntr = gpiochip_get_data(gc);
+ struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
+
+ chip->lines[offset].dir = DIR_IN;

- cntr->stats[offset].dir = IN;
return 0;
}

-static int mockup_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
+static int gpio_mockup_get_direction(struct gpio_chip *gc, unsigned int offset)
{
- struct mockup_gpio_controller *cntr = gpiochip_get_data(gc);
+ struct gpio_mockup_chip *chip = gpiochip_get_data(gc);

- return cntr->stats[offset].dir;
+ return chip->lines[offset].dir;
}

-static int mockup_gpio_add(struct device *dev,
- struct mockup_gpio_controller *cntr,
+static int gpio_mockup_add(struct device *dev,
+ struct gpio_mockup_chip *chip,
const char *name, int base, int ngpio)
{
+ struct gpio_chip *gc = &chip->gc;
int ret;

- cntr->gc.base = base;
- cntr->gc.ngpio = ngpio;
- cntr->gc.label = name;
- cntr->gc.owner = THIS_MODULE;
- cntr->gc.parent = dev;
- cntr->gc.get = mockup_gpio_get;
- cntr->gc.set = mockup_gpio_set;
- cntr->gc.direction_output = mockup_gpio_dirout;
- cntr->gc.direction_input = mockup_gpio_dirin;
- cntr->gc.get_direction = mockup_gpio_get_direction;
- cntr->stats = devm_kzalloc(dev, sizeof(*cntr->stats) * cntr->gc.ngpio,
+ gc->base = base;
+ gc->ngpio = ngpio;
+ gc->label = name;
+ gc->owner = THIS_MODULE;
+ gc->parent = dev;
+ gc->get = gpio_mockup_get;
+ gc->set = gpio_mockup_set;
+ gc->direction_output = gpio_mockup_dirout;
+ gc->direction_input = gpio_mockup_dirin;
+ gc->get_direction = gpio_mockup_get_direction;
+
+ chip->lines = devm_kzalloc(dev, sizeof(*chip->lines) * gc->ngpio,
GFP_KERNEL);
- if (!cntr->stats) {
+ if (!chip->lines) {
ret = -ENOMEM;
goto err;
}
- ret = devm_gpiochip_add_data(dev, &cntr->gc, cntr);
+
+ ret = devm_gpiochip_add_data(dev, &chip->gc, chip);
if (ret)
goto err;

dev_info(dev, "gpio<%d..%d> add successful!", base, base + ngpio);
return 0;
+
err:
dev_err(dev, "gpio<%d..%d> add failed!", base, base + ngpio);
return ret;
}

-static int mockup_gpio_probe(struct platform_device *pdev)
+static int gpio_mockup_probe(struct platform_device *pdev)
{
- struct mockup_gpio_controller *cntr;
+ struct gpio_mockup_chip *chips;
struct device *dev = &pdev->dev;
int ret, i, base, ngpio;
char *chip_name;
@@ -128,15 +134,17 @@ static int mockup_gpio_probe(struct platform_device *pdev)
if (gpio_mockup_params_nr < 2)
return -EINVAL;

- cntr = devm_kzalloc(dev, sizeof(*cntr) * (gpio_mockup_params_nr >> 1),
- GFP_KERNEL);
- if (!cntr)
+ chips = devm_kzalloc(dev,
+ sizeof(*chips) * (gpio_mockup_params_nr >> 1),
+ GFP_KERNEL);
+ if (!chips)
return -ENOMEM;

- platform_set_drvdata(pdev, cntr);
+ platform_set_drvdata(pdev, chips);

for (i = 0; i < gpio_mockup_params_nr >> 1; i++) {
base = gpio_mockup_ranges[i * 2];
+
if (base == -1)
ngpio = gpio_mockup_ranges[i * 2 + 1];
else
@@ -144,16 +152,17 @@ static int mockup_gpio_probe(struct platform_device *pdev)

if (ngpio >= 0) {
chip_name = devm_kasprintf(dev, GFP_KERNEL,
- "%s-%c", GPIO_NAME,
- pins_name_start + i);
+ "%s-%c", GPIO_MOCKUP_NAME,
+ gpio_mockup_name_start + i);
if (!chip_name)
return -ENOMEM;

- ret = mockup_gpio_add(dev, &cntr[i],
+ ret = gpio_mockup_add(dev, &chips[i],
chip_name, base, ngpio);
} else {
ret = -1;
}
+
if (ret) {
if (base < 0)
dev_err(dev, "gpio<%d..%d> add failed\n",
@@ -169,11 +178,11 @@ static int mockup_gpio_probe(struct platform_device *pdev)
return 0;
}

-static struct platform_driver mockup_gpio_driver = {
+static struct platform_driver gpio_mockup_driver = {
.driver = {
- .name = GPIO_NAME,
+ .name = GPIO_MOCKUP_NAME,
},
- .probe = mockup_gpio_probe,
+ .probe = gpio_mockup_probe,
};

static struct platform_device *pdev;
@@ -181,7 +190,7 @@ static int __init mock_device_init(void)
{
int err;

- pdev = platform_device_alloc(GPIO_NAME, -1);
+ pdev = platform_device_alloc(GPIO_MOCKUP_NAME, -1);
if (!pdev)
return -ENOMEM;

@@ -191,7 +200,7 @@ static int __init mock_device_init(void)
return err;
}

- err = platform_driver_register(&mockup_gpio_driver);
+ err = platform_driver_register(&gpio_mockup_driver);
if (err) {
platform_device_unregister(pdev);
return err;
@@ -202,7 +211,7 @@ static int __init mock_device_init(void)

static void __exit mock_device_exit(void)
{
- platform_driver_unregister(&mockup_gpio_driver);
+ platform_driver_unregister(&gpio_mockup_driver);
platform_device_unregister(pdev);
}

--
2.9.3