[PATCH 1/5] gpio: mockup: fix kerneldoc

[PATCH 1/5] gpio: mockup: fix kerneldoc

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

The pull field of the line state struct is undocumented. Fix it.

Fixes: 2a9e27408e12 ("gpio: mockup: rework debugfs interface")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
 drivers/gpio/gpio-mockup.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c
index b32063ac845a..17d4d48524b7 100644
--- a/drivers/gpio/gpio-mockup.c
+++ b/drivers/gpio/gpio-mockup.c
@@ -39,6 +39,8 @@
  * struct gpio_pin_status - structure describing a GPIO status
  * @dir:       Configures direction of gpio as "in" or "out"
  * @value:     Configures status of the gpio as 0(low) or 1(high)
+ * @pull:      Configures the current pull of the GPIO as 0 (pull-down) or
+ *             1 (pull-up)
  */
 struct gpio_mockup_line_status {
 	int dir;
-- 
2.39.2

[PATCH 2/5] gpio: mockup: remove unused field

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

The desc assigned to debugfs private structure is unused so remove it.

Fixes: 9202ba2397d1 ("gpio: mockup: implement event injecting over debugfs")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
 drivers/gpio/gpio-mockup.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c
index 17d4d48524b7..ff1a263f1b05 100644
--- a/drivers/gpio/gpio-mockup.c
+++ b/drivers/gpio/gpio-mockup.c
@@ -58,7 +58,6 @@ struct gpio_mockup_chip {
 
 struct gpio_mockup_dbgfs_private {
 	struct gpio_mockup_chip *chip;
-	struct gpio_desc *desc;
 	unsigned int offset;
 };
 
@@ -369,7 +368,6 @@ static void gpio_mockup_debugfs_setup(struct device *dev,
 
 		priv->chip = chip;
 		priv->offset = i;
-		priv->desc = gpiochip_get_desc(gc, i);
 
 		debugfs_create_file(name, 0600, chip->dbg_dir, priv,
 				    &gpio_mockup_debugfs_ops);
-- 
2.39.2

[PATCH 3/5] gpio: mockup: deprecate the old testing module

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

We have a much better alternative to the clunky old gpio-mockup. Don't
remove it just yet (there are tests depending on it out there) but make
Kconfig say that it should no longer be used in new projects.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
 drivers/gpio/Kconfig | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 673bafb8be58..913948876c93 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -1790,9 +1790,11 @@ config GPIO_LATCH
 	  connected to other GPIOs.
 
 config GPIO_MOCKUP
-	tristate "GPIO Testing Driver"
+	tristate "GPIO Testing Driver (DEPRECATED)"
 	select IRQ_SIM
 	help
+	  This module is DEPRECATED. Please consider using gpio-sim instead.
+
 	  This enables GPIO Testing driver, which provides a way to test GPIO
 	  subsystem through sysfs (or char device) and debugfs.
 	  User could use it through the script in
-- 
2.39.2

[PATCH 4/5] gpio: mockup: simplify code by using cleanup helpers

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Use lock from linux/cleanup.h and simplify locking paths.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
 drivers/gpio/gpio-mockup.c | 45 ++++++++++++++++++--------------------
 1 file changed, 21 insertions(+), 24 deletions(-)

diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c
index ff1a263f1b05..44684ff4462f 100644
--- a/drivers/gpio/gpio-mockup.c
+++ b/drivers/gpio/gpio-mockup.c
@@ -9,6 +9,7 @@
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/cleanup.h>
 #include <linux/debugfs.h>
 #include <linux/gpio/driver.h>
 #include <linux/interrupt.h>
@@ -92,9 +93,8 @@ static int gpio_mockup_get(struct gpio_chip *gc, unsigned int offset)
 	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
 	int val;
 
-	mutex_lock(&chip->lock);
-	val = __gpio_mockup_get(chip, offset);
-	mutex_unlock(&chip->lock);
+	scoped_guard(mutex, &chip->lock)
+		val = __gpio_mockup_get(chip, offset);
 
 	return val;
 }
@@ -105,12 +105,12 @@ static int gpio_mockup_get_multiple(struct gpio_chip *gc,
 	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
 	unsigned int bit, val;
 
-	mutex_lock(&chip->lock);
-	for_each_set_bit(bit, mask, gc->ngpio) {
-		val = __gpio_mockup_get(chip, bit);
-		__assign_bit(bit, bits, val);
+	scoped_guard(mutex, &chip->lock) {
+		for_each_set_bit(bit, mask, gc->ngpio) {
+			val = __gpio_mockup_get(chip, bit);
+			__assign_bit(bit, bits, val);
+		}
 	}
-	mutex_unlock(&chip->lock);
 
 	return 0;
 }
@@ -126,9 +126,9 @@ static void gpio_mockup_set(struct gpio_chip *gc,
 {
 	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
 
-	mutex_lock(&chip->lock);
+	guard(mutex)(&chip->lock);
+
 	__gpio_mockup_set(chip, offset, value);
-	mutex_unlock(&chip->lock);
 }
 
 static void gpio_mockup_set_multiple(struct gpio_chip *gc,
@@ -137,10 +137,10 @@ static void gpio_mockup_set_multiple(struct gpio_chip *gc,
 	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
 	unsigned int bit;
 
-	mutex_lock(&chip->lock);
+	guard(mutex)(&chip->lock);
+
 	for_each_set_bit(bit, mask, gc->ngpio)
 		__gpio_mockup_set(chip, bit, test_bit(bit, bits));
-	mutex_unlock(&chip->lock);
 }
 
 static int gpio_mockup_apply_pull(struct gpio_mockup_chip *chip,
@@ -150,7 +150,7 @@ static int gpio_mockup_apply_pull(struct gpio_mockup_chip *chip,
 	struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
 	int curr, irq, irq_type, ret = 0;
 
-	mutex_lock(&chip->lock);
+	guard(mutex)(&chip->lock);
 
 	if (test_bit(FLAG_REQUESTED, &desc->flags) &&
 	    !test_bit(FLAG_IS_OUT, &desc->flags)) {
@@ -187,7 +187,6 @@ static int gpio_mockup_apply_pull(struct gpio_mockup_chip *chip,
 
 out:
 	chip->lines[offset].pull = value;
-	mutex_unlock(&chip->lock);
 	return ret;
 }
 
@@ -212,10 +211,10 @@ static int gpio_mockup_dirout(struct gpio_chip *gc,
 {
 	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
 
-	mutex_lock(&chip->lock);
-	chip->lines[offset].dir = GPIO_LINE_DIRECTION_OUT;
-	__gpio_mockup_set(chip, offset, value);
-	mutex_unlock(&chip->lock);
+	scoped_guard(mutex, &chip->lock) {
+		chip->lines[offset].dir = GPIO_LINE_DIRECTION_OUT;
+		__gpio_mockup_set(chip, offset, value);
+	}
 
 	return 0;
 }
@@ -224,9 +223,8 @@ static int gpio_mockup_dirin(struct gpio_chip *gc, unsigned int offset)
 {
 	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
 
-	mutex_lock(&chip->lock);
-	chip->lines[offset].dir = GPIO_LINE_DIRECTION_IN;
-	mutex_unlock(&chip->lock);
+	scoped_guard(mutex, &chip->lock)
+		chip->lines[offset].dir = GPIO_LINE_DIRECTION_IN;
 
 	return 0;
 }
@@ -236,9 +234,8 @@ static int gpio_mockup_get_direction(struct gpio_chip *gc, unsigned int offset)
 	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
 	int direction;
 
-	mutex_lock(&chip->lock);
-	direction = chip->lines[offset].dir;
-	mutex_unlock(&chip->lock);
+	scoped_guard(mutex, &chip->lock)
+		direction = chip->lines[offset].dir;
 
 	return direction;
 }
-- 
2.39.2

[PATCH 5/5] gpio: mockup: don't access internal GPIOLIB structures

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Don't include gpiolib.h. Track the request status of lines locally
instead. In order to retrieve the device name use the fact that
gpio-mockup supports only a single GPIO device per platform device and
call device_find_any_child().

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
 drivers/gpio/gpio-mockup.c | 39 +++++++++++++++++++++++++++++---------
 1 file changed, 30 insertions(+), 9 deletions(-)

diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c
index 44684ff4462f..4870e267a402 100644
--- a/drivers/gpio/gpio-mockup.c
+++ b/drivers/gpio/gpio-mockup.c
@@ -11,6 +11,7 @@
 
 #include <linux/cleanup.h>
 #include <linux/debugfs.h>
+#include <linux/device.h>
 #include <linux/gpio/driver.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>
@@ -25,8 +26,6 @@
 #include <linux/string_helpers.h>
 #include <linux/uaccess.h>
 
-#include "gpiolib.h"
-
 #define GPIO_MOCKUP_MAX_GC	10
 /*
  * We're storing two values per chip: the GPIO base and the number
@@ -42,11 +41,13 @@
  * @value:     Configures status of the gpio as 0(low) or 1(high)
  * @pull:      Configures the current pull of the GPIO as 0 (pull-down) or
  *             1 (pull-up)
+ * @requested: Request status of this GPIO
  */
 struct gpio_mockup_line_status {
 	int dir;
 	int value;
 	int pull;
+	bool requested;
 };
 
 struct gpio_mockup_chip {
@@ -146,14 +147,12 @@ static void gpio_mockup_set_multiple(struct gpio_chip *gc,
 static int gpio_mockup_apply_pull(struct gpio_mockup_chip *chip,
 				  unsigned int offset, int value)
 {
-	struct gpio_chip *gc = &chip->gc;
-	struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
+	struct gpio_mockup_line_status *line = &chip->lines[offset];
 	int curr, irq, irq_type, ret = 0;
 
 	guard(mutex)(&chip->lock);
 
-	if (test_bit(FLAG_REQUESTED, &desc->flags) &&
-	    !test_bit(FLAG_IS_OUT, &desc->flags)) {
+	if (line->requested && line->dir == GPIO_LINE_DIRECTION_IN) {
 		curr = __gpio_mockup_get(chip, offset);
 		if (curr == value)
 			goto out;
@@ -181,8 +180,7 @@ static int gpio_mockup_apply_pull(struct gpio_mockup_chip *chip,
 
 set_value:
 	/* Change the value unless we're actively driving the line. */
-	if (!test_bit(FLAG_REQUESTED, &desc->flags) ||
-	    !test_bit(FLAG_IS_OUT, &desc->flags))
+	if (!line->requested || line->dir == GPIO_LINE_DIRECTION_IN)
 		__gpio_mockup_set(chip, offset, value);
 
 out:
@@ -247,10 +245,23 @@ static int gpio_mockup_to_irq(struct gpio_chip *gc, unsigned int offset)
 	return irq_create_mapping(chip->irq_sim_domain, offset);
 }
 
+static int gpio_mockup_request(struct gpio_chip *gc, unsigned int offset)
+{
+	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
+
+	scoped_guard(mutex, &chip->lock)
+		chip->lines[offset].requested = true;
+
+	return 0;
+}
+
 static void gpio_mockup_free(struct gpio_chip *gc, unsigned int offset)
 {
 	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
 
+	guard(mutex)(&chip->lock);
+
+	chip->lines[offset].requested = false;
 	__gpio_mockup_set(chip, offset, chip->lines[offset].pull);
 }
 
@@ -343,6 +354,7 @@ static const struct file_operations gpio_mockup_debugfs_ops = {
 static void gpio_mockup_debugfs_setup(struct device *dev,
 				      struct gpio_mockup_chip *chip)
 {
+	struct device *child __free(put_device) = NULL;
 	struct gpio_mockup_dbgfs_private *priv;
 	struct gpio_chip *gc;
 	const char *devname;
@@ -350,8 +362,16 @@ static void gpio_mockup_debugfs_setup(struct device *dev,
 	int i;
 
 	gc = &chip->gc;
-	devname = dev_name(&gc->gpiodev->dev);
 
+	/*
+	 * There can only be a single GPIO device per platform device in
+	 * gpio-mockup so using device_find_any_child() is OK.
+	 */
+	child = device_find_any_child(dev);
+	if (!child)
+		return;
+
+	devname = dev_name(child);
 	chip->dbg_dir = debugfs_create_dir(devname, gpio_mockup_dbg_dir);
 
 	for (i = 0; i < gc->ngpio; i++) {
@@ -435,6 +455,7 @@ static int gpio_mockup_probe(struct platform_device *pdev)
 	gc->get_direction = gpio_mockup_get_direction;
 	gc->set_config = gpio_mockup_set_config;
 	gc->to_irq = gpio_mockup_to_irq;
+	gc->request = gpio_mockup_request;
 	gc->free = gpio_mockup_free;
 
 	chip->lines = devm_kcalloc(dev, gc->ngpio,
-- 
2.39.2

Re: [PATCH 1/5] gpio: mockup: fix kerneldoc

[Andy Shevchenko]

On Thu, Sep 07, 2023 at 04:52:26PM +0200, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
> 
> The pull field of the line state struct is undocumented. Fix it.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

for the entire series.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH 1/5] gpio: mockup: fix kerneldoc

[Linus Walleij]

On Thu, Sep 7, 2023 at 4:52 PM Bartosz Golaszewski <brgl@bgdev.pl> wrote:

> From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
>
> The pull field of the line state struct is undocumented. Fix it.
>
> Fixes: 2a9e27408e12 ("gpio: mockup: rework debugfs interface")
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

For the whole series.

Yours,
Linus Walleij