[PATCH v2 0/7] gpio: mockup: extensions for testing purposes

[PATCH v2 0/7] gpio: mockup: extensions for testing purposes

[Bartosz Golaszewski]

I would like to create an automated test-suite for libgpiod, but
the gpio-mockup driver is quite limited when it comes to current
user space functionality - I can't test neither line event
notifications nor finding GPIO lines by name.

This series proposes to extend the gpio framework by allowing to
inject line events from the kernel code and by providing a debugfs
interface for that to the gpio-mockup driver. We also allow the
user to request that the mockup driver name the lines.

The first two patches only contain coding style changes which, I
believe, will make the driver easier to maintain.

The third patch adds the option to have the lines named.

The fourth patch adds a devres flavor of irq_alloc_descs() to be used
in patch 5, which actually adds the dummy irqchip.

The last two patches implement the debugfs directory structure that
can be used by the user space to inject line events.

v1 -> v2:
- made the event injection self-contained within the driver by using
  the irq_work as suggested by Lars-Peter Clauses

Bartosz Golaszewski (7):
  gpio: mockup: readability tweaks
  gpio: mockup: code shrink
  gpio: mockup: implement naming the lines
  irqdesc: add memory managed version of irq_alloc_descs()
  gpio: mockup: add a dummy irqchip
  gpiolib: include <gpio/consumer.h> from gpiolib.h
  gpio: mockup: implement event injecting over debugfs

 drivers/gpio/Kconfig       |   1 +
 drivers/gpio/gpio-mockup.c | 349 ++++++++++++++++++++++++++++++++++++---------
 drivers/gpio/gpiolib.h     |   1 +
 include/linux/irq.h        |  19 +++
 kernel/irq/devres.c        |  38 +++++
 5 files changed, 338 insertions(+), 70 deletions(-)

-- 
2.9.3

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

[Bartosz Golaszewski]

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@baylibre.com>
---
 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

[PATCH v2 2/7] gpio: mockup: code shrink

[Bartosz Golaszewski]

Moving a couple of lines around allows us to shrink the code a bit
while keeping the same functionality.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/gpio/gpio-mockup.c | 29 ++++++++---------------------
 1 file changed, 8 insertions(+), 21 deletions(-)

diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c
index 5f6ed4b..d425601 100644
--- a/drivers/gpio/gpio-mockup.c
+++ b/drivers/gpio/gpio-mockup.c
@@ -92,7 +92,6 @@ static int gpio_mockup_add(struct device *dev,
 			   const char *name, int base, int ngpio)
 {
 	struct gpio_chip *gc = &chip->gc;
-	int ret;
 
 	gc->base = base;
 	gc->ngpio = ngpio;
@@ -107,21 +106,10 @@ static int gpio_mockup_add(struct device *dev,
 
 	chip->lines = devm_kzalloc(dev, sizeof(*chip->lines) * gc->ngpio,
 				   GFP_KERNEL);
-	if (!chip->lines) {
-		ret = -ENOMEM;
-		goto err;
-	}
-
-	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;
+	if (!chip->lines)
+		return -ENOMEM;
 
-err:
-	dev_err(dev, "gpio<%d..%d> add failed!", base, base + ngpio);
-	return ret;
+	return devm_gpiochip_add_data(dev, &chip->gc, chip);
 }
 
 static int gpio_mockup_probe(struct platform_device *pdev)
@@ -164,15 +152,14 @@ static int gpio_mockup_probe(struct platform_device *pdev)
 		}
 
 		if (ret) {
-			if (base < 0)
-				dev_err(dev, "gpio<%d..%d> add failed\n",
-					base, ngpio);
-			else
-				dev_err(dev, "gpio<%d..%d> add failed\n",
-					base, base + ngpio);
+			dev_err(dev, "gpio<%d..%d> add failed\n",
+				base, base < 0 ? ngpio : base + ngpio);
 
 			return ret;
 		}
+
+		dev_info(dev, "gpio<%d..%d> add successful!",
+			 base, base + ngpio);
 	}
 
 	return 0;
-- 
2.9.3

[PATCH v2 3/7] gpio: mockup: implement naming the lines

[Bartosz Golaszewski]

In order to allow testing line lookup by name from user space, add
a new boolean parameter that indicates whether we want the lines to
be named. The name is created by concatenating the chip name and the
line offset value.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/gpio/gpio-mockup.c | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c
index d425601..0ce9acc3 100644
--- a/drivers/gpio/gpio-mockup.c
+++ b/drivers/gpio/gpio-mockup.c
@@ -15,6 +15,7 @@
 #include <linux/module.h>
 #include <linux/gpio/driver.h>
 #include <linux/platform_device.h>
+#include <linux/slab.h>
 
 #define GPIO_MOCKUP_NAME	"gpio-mockup"
 #define	GPIO_MOCKUP_MAX_GC	10
@@ -43,6 +44,10 @@ 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 bool gpio_mockup_named_lines;
+module_param_named(gpio_mockup_named_lines,
+		   gpio_mockup_named_lines, bool, 0400);
+
 static const char gpio_mockup_name_start = 'A';
 
 static int gpio_mockup_get(struct gpio_chip *gc, unsigned int offset)
@@ -87,11 +92,35 @@ static int gpio_mockup_get_direction(struct gpio_chip *gc, unsigned int offset)
 	return chip->lines[offset].dir;
 }
 
+static int gpio_mockup_name_lines(struct device *dev,
+				  struct gpio_mockup_chip *chip)
+{
+	struct gpio_chip *gc = &chip->gc;
+	char **names;
+	int i;
+
+	names = devm_kzalloc(dev, sizeof(char *) * gc->ngpio, GFP_KERNEL);
+	if (!names)
+		return -ENOMEM;
+
+	for (i = 0; i < gc->ngpio; i++) {
+		names[i] = devm_kasprintf(dev, GFP_KERNEL,
+					  "%s-%d", gc->label, i);
+		if (!names[i])
+			return -ENOMEM;
+	}
+
+	gc->names = (const char *const *)names;
+
+	return 0;
+}
+
 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;
 
 	gc->base = base;
 	gc->ngpio = ngpio;
@@ -109,6 +138,12 @@ static int gpio_mockup_add(struct device *dev,
 	if (!chip->lines)
 		return -ENOMEM;
 
+	if (gpio_mockup_named_lines) {
+		ret = gpio_mockup_name_lines(dev, chip);
+		if (ret)
+			return ret;
+	}
+
 	return devm_gpiochip_add_data(dev, &chip->gc, chip);
 }
 
-- 
2.9.3

[PATCH v2 4/7] irqdesc: add memory managed version of irq_alloc_descs()

[Bartosz Golaszewski]

Add a devres flavor of __devm_irq_alloc_descs() and corresponding
helper macros.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 include/linux/irq.h | 19 +++++++++++++++++++
 kernel/irq/devres.c | 38 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 57 insertions(+)

diff --git a/include/linux/irq.h b/include/linux/irq.h
index e798755..d915cae 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -715,6 +715,10 @@ unsigned int arch_dynirq_lower_bound(unsigned int from);
 int __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
 		      struct module *owner, const struct cpumask *affinity);
 
+int __devm_irq_alloc_descs(struct device *dev, int irq, unsigned int from,
+			   unsigned int cnt, int node, struct module *owner,
+			   const struct cpumask *affinity);
+
 /* use macros to avoid needing export.h for THIS_MODULE */
 #define irq_alloc_descs(irq, from, cnt, node)	\
 	__irq_alloc_descs(irq, from, cnt, node, THIS_MODULE, NULL)
@@ -731,6 +735,21 @@ int __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
 #define irq_alloc_descs_from(from, cnt, node)	\
 	irq_alloc_descs(-1, from, cnt, node)
 
+#define devm_irq_alloc_descs(dev, irq, from, cnt, node)		\
+	__devm_irq_alloc_descs(dev, irq, from, cnt, node, THIS_MODULE, NULL)
+
+#define devm_irq_alloc_desc(dev, node)				\
+	devm_irq_alloc_descs(dev, -1, 0, 1, node)
+
+#define devm_irq_alloc_desc_at(dev, at, node)			\
+	devm_irq_alloc_descs(dev, at, at, 1, node)
+
+#define devm_irq_alloc_desc_from(dev, from, node)		\
+	devm_irq_alloc_descs(dev, -1, from, 1, node)
+
+#define devm_irq_alloc_descs_from(dev, from, cnt, node)		\
+	devm_irq_alloc_descs(dev, -1, from, cnt, node)
+
 void irq_free_descs(unsigned int irq, unsigned int cnt);
 static inline void irq_free_desc(unsigned int irq)
 {
diff --git a/kernel/irq/devres.c b/kernel/irq/devres.c
index 74d90a7..d1e70d6 100644
--- a/kernel/irq/devres.c
+++ b/kernel/irq/devres.c
@@ -2,6 +2,7 @@
 #include <linux/interrupt.h>
 #include <linux/device.h>
 #include <linux/gfp.h>
+#include <linux/irq.h>
 
 /*
  * Device resource management aware IRQ request/free implementation.
@@ -137,3 +138,40 @@ void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id)
 	free_irq(irq, dev_id);
 }
 EXPORT_SYMBOL(devm_free_irq);
+
+struct irq_desc_devres {
+	int from;
+	int cnt;
+};
+
+static void devm_irq_desc_release(struct device *dev, void *res)
+{
+	struct irq_desc_devres *this = res;
+
+	irq_free_descs(this->from, this->cnt);
+}
+
+int __devm_irq_alloc_descs(struct device *dev, int irq, unsigned int from,
+			   unsigned int cnt, int node, struct module *owner,
+			   const struct cpumask *affinity)
+{
+	struct irq_desc_devres *dr;
+	int base;
+
+	dr = devres_alloc(devm_irq_desc_release, sizeof(*dr), GFP_KERNEL);
+	if (!dr)
+		return -ENOMEM;
+
+	base = __irq_alloc_descs(irq, from, cnt, node, owner, affinity);
+	if (base < 0) {
+		devres_free(dr);
+		return base;
+	}
+
+	dr->from = base;
+	dr->cnt = cnt;
+	devres_add(dev, dr);
+
+	return base;
+}
+EXPORT_SYMBOL_GPL(__devm_irq_alloc_descs);
-- 
2.9.3

[PATCH v2 5/7] gpio: mockup: add a dummy irqchip

[Bartosz Golaszewski]

Setup a dummy irqchip that will allow us to inject line events for
testing purposes.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/gpio/Kconfig       |  1 +
 drivers/gpio/gpio-mockup.c | 65 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 66 insertions(+)

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 2d77392..db6ff78 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -298,6 +298,7 @@ config GPIO_MOCKUP
 	tristate "GPIO Testing Driver"
 	depends on GPIOLIB && SYSFS
 	select GPIO_SYSFS
+	select GPIOLIB_IRQCHIP
 	help
 	  This enables GPIO Testing driver, which provides a way to test GPIO
 	  subsystem through sysfs(or char device) and debugfs. GPIO_SYSFS
diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c
index 0ce9acc3..7d82d35 100644
--- a/drivers/gpio/gpio-mockup.c
+++ b/drivers/gpio/gpio-mockup.c
@@ -16,6 +16,9 @@
 #include <linux/gpio/driver.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irq_work.h>
 
 #define GPIO_MOCKUP_NAME	"gpio-mockup"
 #define	GPIO_MOCKUP_MAX_GC	10
@@ -35,9 +38,15 @@ struct gpio_mockup_line_status {
 	bool value;
 };
 
+struct gpio_mockup_irq_context {
+	struct irq_work work;
+	int irq;
+};
+
 struct gpio_mockup_chip {
 	struct gpio_chip gc;
 	struct gpio_mockup_line_status *lines;
+	struct gpio_mockup_irq_context irq_ctx;
 };
 
 static int gpio_mockup_ranges[GPIO_MOCKUP_MAX_GC << 1];
@@ -115,6 +124,57 @@ static int gpio_mockup_name_lines(struct device *dev,
 	return 0;
 }
 
+static int gpio_mockup_to_irq(struct gpio_chip *chip, unsigned int offset)
+{
+	return chip->irq_base + offset;
+}
+
+/*
+ * While we should generally support irqmask and irqunmask, this driver is
+ * for testing purposes only so we don't care.
+ */
+static void gpio_mockup_irqmask(struct irq_data *d) { }
+static void gpio_mockup_irqunmask(struct irq_data *d) { }
+
+static struct irq_chip gpio_mockup_irqchip = {
+	.name		= GPIO_MOCKUP_NAME,
+	.irq_mask	= gpio_mockup_irqmask,
+	.irq_unmask	= gpio_mockup_irqunmask,
+};
+
+static void gpio_mockup_handle_irq(struct irq_work *work)
+{
+	struct gpio_mockup_irq_context *irq_ctx;
+
+	irq_ctx = container_of(work, struct gpio_mockup_irq_context, work);
+	handle_simple_irq(irq_to_desc(irq_ctx->irq));
+}
+
+static int gpio_mockup_irqchip_setup(struct device *dev,
+				     struct gpio_mockup_chip *chip)
+{
+	struct gpio_chip *gc = &chip->gc;
+	int irq_base, i;
+
+	irq_base = devm_irq_alloc_descs(dev, -1, 0, gc->ngpio, 0);
+	if (irq_base < 0)
+		return irq_base;
+
+	gc->irq_base = irq_base;
+	gc->irqchip = &gpio_mockup_irqchip;
+
+	for (i = 0; i < gc->ngpio; i++) {
+		irq_set_chip(irq_base + i, gc->irqchip);
+		irq_set_handler(irq_base + i, &handle_simple_irq);
+		irq_modify_status(irq_base + i,
+				  IRQ_NOREQUEST | IRQ_NOAUTOEN, IRQ_NOPROBE);
+	}
+
+	init_irq_work(&chip->irq_ctx.work, gpio_mockup_handle_irq);
+
+	return 0;
+}
+
 static int gpio_mockup_add(struct device *dev,
 			   struct gpio_mockup_chip *chip,
 			   const char *name, int base, int ngpio)
@@ -132,6 +192,7 @@ static int gpio_mockup_add(struct device *dev,
 	gc->direction_output = gpio_mockup_dirout;
 	gc->direction_input = gpio_mockup_dirin;
 	gc->get_direction = gpio_mockup_get_direction;
+	gc->to_irq = gpio_mockup_to_irq;
 
 	chip->lines = devm_kzalloc(dev, sizeof(*chip->lines) * gc->ngpio,
 				   GFP_KERNEL);
@@ -144,6 +205,10 @@ static int gpio_mockup_add(struct device *dev,
 			return ret;
 	}
 
+	ret = gpio_mockup_irqchip_setup(dev, chip);
+	if (ret)
+		return ret;
+
 	return devm_gpiochip_add_data(dev, &chip->gc, chip);
 }
 
-- 
2.9.3

[PATCH v2 6/7] gpiolib: include <gpio/consumer.h> from gpiolib.h

[Bartosz Golaszewski]

We want pull gpiolib.h in from the gpio mockup driver, but gpiod_flags
is defined in consumer.h, so we need that too indirectly.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/gpio/gpiolib.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h
index 2495b7e..067e5e5 100644
--- a/drivers/gpio/gpiolib.h
+++ b/drivers/gpio/gpiolib.h
@@ -13,6 +13,7 @@
 #define GPIOLIB_H
 
 #include <linux/gpio/driver.h>
+#include <linux/gpio/consumer.h>
 #include <linux/err.h>
 #include <linux/device.h>
 #include <linux/module.h>
-- 
2.9.3

[PATCH v2 7/7] gpio: mockup: implement event injecting over debugfs

[Bartosz Golaszewski]

Create a debugfs directory for every mockup chip and a single file
for every line. Writing (0 or 1) to these files allows the user to
inject line events (falling or rising edge respectively).

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/gpio/gpio-mockup.c | 115 ++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 114 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c
index 7d82d35..449918b 100644
--- a/drivers/gpio/gpio-mockup.c
+++ b/drivers/gpio/gpio-mockup.c
@@ -19,6 +19,10 @@
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/irq_work.h>
+#include <linux/debugfs.h>
+#include <linux/uaccess.h>
+
+#include "gpiolib.h"
 
 #define GPIO_MOCKUP_NAME	"gpio-mockup"
 #define	GPIO_MOCKUP_MAX_GC	10
@@ -47,6 +51,13 @@ struct gpio_mockup_chip {
 	struct gpio_chip gc;
 	struct gpio_mockup_line_status *lines;
 	struct gpio_mockup_irq_context irq_ctx;
+	struct dentry *dbg_dir;
+};
+
+struct gpio_mockup_dbgfs_private {
+	struct gpio_mockup_chip *chip;
+	struct gpio_desc *desc;
+	int offset;
 };
 
 static int gpio_mockup_ranges[GPIO_MOCKUP_MAX_GC << 1];
@@ -58,6 +69,7 @@ module_param_named(gpio_mockup_named_lines,
 		   gpio_mockup_named_lines, bool, 0400);
 
 static const char gpio_mockup_name_start = 'A';
+static struct dentry *gpio_mockup_dbg_dir;
 
 static int gpio_mockup_get(struct gpio_chip *gc, unsigned int offset)
 {
@@ -175,6 +187,94 @@ static int gpio_mockup_irqchip_setup(struct device *dev,
 	return 0;
 }
 
+static ssize_t gpio_mockup_event_write(struct file *file,
+				       const char __user *usr_buf,
+				       size_t size, loff_t *ppos)
+{
+	struct gpio_mockup_dbgfs_private *priv;
+	struct gpio_mockup_chip *chip;
+	struct seq_file *sfile;
+	struct gpio_desc *desc;
+	struct gpio_chip *gc;
+	int status, val;
+	char buf;
+
+	sfile = file->private_data;
+	priv = sfile->private;
+	desc = priv->desc;
+	chip = priv->chip;
+	gc = &chip->gc;
+
+	status = copy_from_user(&buf, usr_buf, 1);
+	if (status)
+		return status;
+
+	if (buf == '0')
+		val = 0;
+	else if (buf == '1')
+		val = 1;
+	else
+		return -EINVAL;
+
+	gpiod_set_value_cansleep(desc, val);
+	priv->chip->irq_ctx.irq = gc->irq_base + priv->offset;
+	irq_work_queue(&priv->chip->irq_ctx.work);
+
+	return size;
+}
+
+static int gpio_mockup_event_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, NULL, inode->i_private);
+}
+
+static const struct file_operations gpio_mockup_event_ops = {
+	.owner = THIS_MODULE,
+	.open = gpio_mockup_event_open,
+	.write = gpio_mockup_event_write,
+	.llseek = no_llseek,
+};
+
+static void gpio_mockup_debugfs_setup(struct device *dev,
+				      struct gpio_mockup_chip *chip)
+{
+	struct gpio_mockup_dbgfs_private *priv;
+	struct dentry *evfile;
+	struct gpio_chip *gc;
+	char *name;
+	int i;
+
+	gc = &chip->gc;
+
+	chip->dbg_dir = debugfs_create_dir(gc->label, gpio_mockup_dbg_dir);
+	if (!chip->dbg_dir)
+		goto err;
+
+	for (i = 0; i < gc->ngpio; i++) {
+		name = devm_kasprintf(dev, GFP_KERNEL, "%d", i);
+		if (!name)
+			goto err;
+
+		priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+		if (!priv)
+			goto err;
+
+		priv->chip = chip;
+		priv->offset = i;
+		priv->desc = &gc->gpiodev->descs[i];
+
+		evfile = debugfs_create_file(name, 0200, chip->dbg_dir, priv,
+					     &gpio_mockup_event_ops);
+		if (!evfile)
+			goto err;
+	}
+
+	return;
+
+err:
+	dev_err(dev, "error creating debugfs directory\n");
+}
+
 static int gpio_mockup_add(struct device *dev,
 			   struct gpio_mockup_chip *chip,
 			   const char *name, int base, int ngpio)
@@ -209,7 +309,14 @@ static int gpio_mockup_add(struct device *dev,
 	if (ret)
 		return ret;
 
-	return devm_gpiochip_add_data(dev, &chip->gc, chip);
+	ret = devm_gpiochip_add_data(dev, &chip->gc, chip);
+	if (ret)
+		return ret;
+
+	if (gpio_mockup_dbg_dir)
+		gpio_mockup_debugfs_setup(dev, chip);
+
+	return 0;
 }
 
 static int gpio_mockup_probe(struct platform_device *pdev)
@@ -277,6 +384,11 @@ static int __init mock_device_init(void)
 {
 	int err;
 
+	gpio_mockup_dbg_dir = debugfs_create_dir("gpio-mockup-event", NULL);
+	if (!gpio_mockup_dbg_dir)
+		pr_err("%s: error creating debugfs directory\n",
+		       GPIO_MOCKUP_NAME);
+
 	pdev = platform_device_alloc(GPIO_MOCKUP_NAME, -1);
 	if (!pdev)
 		return -ENOMEM;
@@ -298,6 +410,7 @@ static int __init mock_device_init(void)
 
 static void __exit mock_device_exit(void)
 {
+	debugfs_remove_recursive(gpio_mockup_dbg_dir);
 	platform_driver_unregister(&gpio_mockup_driver);
 	platform_device_unregister(pdev);
 }
-- 
2.9.3

Re: [PATCH v2 0/7] gpio: mockup: extensions for testing purposes

[Bartosz Golaszewski]

2017-02-06 13:10 GMT+01:00 Bartosz Golaszewski <bgolaszewski@baylibre.com>:
> I would like to create an automated test-suite for libgpiod, but
> the gpio-mockup driver is quite limited when it comes to current
> user space functionality - I can't test neither line event
> notifications nor finding GPIO lines by name.
>
> This series proposes to extend the gpio framework by allowing to
> inject line events from the kernel code and by providing a debugfs
> interface for that to the gpio-mockup driver. We also allow the
> user to request that the mockup driver name the lines.
>
> The first two patches only contain coding style changes which, I
> believe, will make the driver easier to maintain.
>
> The third patch adds the option to have the lines named.
>
> The fourth patch adds a devres flavor of irq_alloc_descs() to be used
> in patch 5, which actually adds the dummy irqchip.
>
> The last two patches implement the debugfs directory structure that
> can be used by the user space to inject line events.
>
> v1 -> v2:
> - made the event injection self-contained within the driver by using
>   the irq_work as suggested by Lars-Peter Clauses

s/ Lars-Peter Clauses/ Lars-Peter Clausen/

sorry!

Thanks,
Bartosz

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

[Linus Walleij]

On Mon, Feb 6, 2017 at 1:10 PM, Bartosz Golaszewski
<bgolaszewski@baylibre.com> wrote:

> 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@baylibre.com>

Patch applied.

Yours,
Linus Walleij

Re: [PATCH v2 2/7] gpio: mockup: code shrink

[Linus Walleij]

On Mon, Feb 6, 2017 at 1:10 PM, Bartosz Golaszewski
<bgolaszewski@baylibre.com> wrote:

> Moving a couple of lines around allows us to shrink the code a bit
> while keeping the same functionality.
>
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Patch applied.

Yours,
Linus Walleij

Re: [PATCH v2 3/7] gpio: mockup: implement naming the lines

[Linus Walleij]

On Mon, Feb 6, 2017 at 1:10 PM, Bartosz Golaszewski
<bgolaszewski@baylibre.com> wrote:

> In order to allow testing line lookup by name from user space, add
> a new boolean parameter that indicates whether we want the lines to
> be named. The name is created by concatenating the chip name and the
> line offset value.
>
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Patch applied.

Yours,
Linus Walleij

Re: [PATCH v2 4/7] irqdesc: add memory managed version of irq_alloc_descs()

[Linus Walleij]

On Mon, Feb 6, 2017 at 1:10 PM, Bartosz Golaszewski
<bgolaszewski@baylibre.com> wrote:

> Add a devres flavor of __devm_irq_alloc_descs() and corresponding
> helper macros.
>
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Oh that was interesting. I will leave the IRQ subsystems specific
review to Thomas and Marc, but I think you need to also update
Documentation/driver-model/devres.txt
where you find a long list of all memorymanaged API calls.

Maybe the list is a bit silly actually, but anyway.

Yours,
Linus Walleij

Re: [PATCH v2 5/7] gpio: mockup: add a dummy irqchip

[Linus Walleij]

On Mon, Feb 6, 2017 at 1:10 PM, Bartosz Golaszewski
<bgolaszewski@baylibre.com> wrote:

> Setup a dummy irqchip that will allow us to inject line events for
> testing purposes.
>
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

This is obviously exactly how we should do this.

However since it needs the devm* helpers from the irq
subsystem I can't apply them until the irqchip maintainers
merge or ack that patch.

If you want it in soon I suggest resending it with
non-memorymanaged accessors for the descs and later
make a separate patch to switch over to the devm_*
versions when/if it is accepted.

If you're not in a hurry, just wait :)

Yours,
Linus Walleij

Re: [PATCH v2 6/7] gpiolib: include <gpio/consumer.h> from gpiolib.h

[Linus Walleij]

On Mon, Feb 6, 2017 at 1:10 PM, Bartosz Golaszewski
<bgolaszewski@baylibre.com> wrote:

> We want pull gpiolib.h in from the gpio mockup driver, but gpiod_flags
> is defined in consumer.h, so we need that too indirectly.
>
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Can't you just add the include to the mockup driver...?

Yours,
Linus Walleij

Re: [PATCH v2 5/7] gpio: mockup: add a dummy irqchip

[Bartosz Golaszewski]

2017-02-06 14:29 GMT+01:00 Linus Walleij <linus.walleij@linaro.org>:
> On Mon, Feb 6, 2017 at 1:10 PM, Bartosz Golaszewski
> <bgolaszewski@baylibre.com> wrote:
>
>> Setup a dummy irqchip that will allow us to inject line events for
>> testing purposes.
>>
>> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>
> This is obviously exactly how we should do this.
>
> However since it needs the devm* helpers from the irq
> subsystem I can't apply them until the irqchip maintainers
> merge or ack that patch.
>
> If you want it in soon I suggest resending it with
> non-memorymanaged accessors for the descs and later
> make a separate patch to switch over to the devm_*
> versions when/if it is accepted.
>
> If you're not in a hurry, just wait :)
>
> Yours,
> Linus Walleij

I think I'll do it, since it would be nice to have it go in for 4.11
(if you're ready to merge it that late into the release cycle).

Thanks,
Bartosz

Re: [PATCH v2 5/7] gpio: mockup: add a dummy irqchip

[Linus Walleij]

On Mon, Feb 6, 2017 at 2:31 PM, Bartosz Golaszewski
<bgolaszewski@baylibre.com> wrote:
> 2017-02-06 14:29 GMT+01:00 Linus Walleij <linus.walleij@linaro.org>:
>> On Mon, Feb 6, 2017 at 1:10 PM, Bartosz Golaszewski
>> <bgolaszewski@baylibre.com> wrote:
>>
>>> Setup a dummy irqchip that will allow us to inject line events for
>>> testing purposes.
>>>
>>> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>>
>> This is obviously exactly how we should do this.
>>
>> However since it needs the devm* helpers from the irq
>> subsystem I can't apply them until the irqchip maintainers
>> merge or ack that patch.
>>
>> If you want it in soon I suggest resending it with
>> non-memorymanaged accessors for the descs and later
>> make a separate patch to switch over to the devm_*
>> versions when/if it is accepted.
>>
>> If you're not in a hurry, just wait :)
>>
>> Yours,
>> Linus Walleij
>
> I think I'll do it, since it would be nice to have it go in for 4.11
> (if you're ready to merge it that late into the release cycle).

I will merge this. Expanding the testing is paramount.

Yours,
Linus Walleij