Skip to contentSkip to conversation

gpio: mockup: use device properties instead of platform_data

PATCH In review Bartosz Golaszewski 2 participants 2 messages Sep 25, 2018 – Oct 3, 2018

Subsystems (2)
lore
Share & tools
lore
#0 lore raw

PATCH v2 1/1 gpio: mockup: use device properties instead of platform_data

Some users want to introduce device tree support to the mockup driver. Let's make it easier by switching to using generic device properties. The driver stays compatible with previous use cases and after this conversion there'll be no need to change the way probing of mockup GPIO chips works.

Tested with libgpiod test suite.

---
v1 -> v2:
- dropped an unnecessary check when reading the base gpio number property

 drivers/gpio/gpio-mockup.c | 82 ++++++++++++++++++++++++--------------
 1 file changed, 51 insertions(+), 31 deletions(-)
drivers/gpio/gpio-mockup.c +51 -31
index d66b7a768ecd..8269cffc2967 100644
@@ -18,6 +18,7 @@
 #include <linux/irq_sim.h>
 #include <linux/debugfs.h>
 #include <linux/uaccess.h>
+#include <linux/property.h>
 
 #include "gpiolib.h"
 
@@ -28,6 +29,8 @@
  * of GPIO lines.
  */
 #define GPIO_MOCKUP_MAX_RANGES	(GPIO_MOCKUP_MAX_GC * 2)
+/* Maximum of three properties + the sentinel. */
+#define GPIO_MOCKUP_MAX_PROP	4
 
 #define gpio_mockup_err(...)	pr_err(GPIO_MOCKUP_NAME ": " __VA_ARGS__)
 
@@ -59,13 +62,6 @@ struct gpio_mockup_dbgfs_private {
 	int offset;
 };
 
-struct gpio_mockup_platform_data {
-	int base;
-	int ngpio;
-	int index;
-	bool named_lines;
-};
-
 static int gpio_mockup_ranges[GPIO_MOCKUP_MAX_RANGES];
 static int gpio_mockup_num_ranges;
 module_param_array(gpio_mockup_ranges, int, &gpio_mockup_num_ranges, 0400);
@@ -255,26 +251,37 @@ static int gpio_mockup_name_lines(struct device *dev,
 
 static int gpio_mockup_probe(struct platform_device *pdev)
 {
-	struct gpio_mockup_platform_data *pdata;
 	struct gpio_mockup_chip *chip;
 	struct gpio_chip *gc;
-	int rv, base, ngpio;
 	struct device *dev;
-	char *name;
+	const char *name;
+	int rv, base;
+	u16 ngpio;
 
 	dev = &pdev->dev;
-	pdata = dev_get_platdata(dev);
-	base = pdata->base;
-	ngpio = pdata->ngpio;
+
+	rv = device_property_read_u32(dev, "gpio-base", &base);
+	if (rv)
+		base = -1;
+
+	rv = device_property_read_u16(dev, "nr-gpios", &ngpio);
+	if (rv)
+		return rv;
+
+	rv = device_property_read_string(dev, "chip-name", &name);
+	if (rv)
+		name = NULL;
 
 	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
 	if (!chip)
 		return -ENOMEM;
 
-	name = devm_kasprintf(dev, GFP_KERNEL, "%s-%c",
-			      pdev->name, pdata->index);
-	if (!name)
-		return -ENOMEM;
+	if (!name) {
+		name = devm_kasprintf(dev, GFP_KERNEL,
+				      "%s-%c", pdev->name, pdev->id + 'A');
+		if (!name)
+			return -ENOMEM;
+	}
 
 	gc = &chip->gc;
 	gc->base = base;
@@ -295,7 +302,7 @@ static int gpio_mockup_probe(struct platform_device *pdev)
 	if (!chip->lines)
 		return -ENOMEM;
 
-	if (pdata->named_lines) {
+	if (device_property_read_bool(dev, "named-gpio-lines")) {
 		rv = gpio_mockup_name_lines(dev, chip);
 		if (rv)
 			return rv;
@@ -339,9 +346,11 @@ static void gpio_mockup_unregister_pdevs(void)
 
 static int __init gpio_mockup_init(void)
 {
-	int i, num_chips, err = 0, index = 'A';
-	struct gpio_mockup_platform_data pdata;
+	struct property_entry properties[GPIO_MOCKUP_MAX_PROP];
+	int i, prop, num_chips, err = 0, base;
+	struct platform_device_info pdevinfo;
 	struct platform_device *pdev;
+	u16 ngpio;
 
 	if ((gpio_mockup_num_ranges < 2) ||
 	    (gpio_mockup_num_ranges % 2) ||
@@ -371,17 +380,28 @@ static int __init gpio_mockup_init(void)
 	}
 
 	for (i = 0; i < num_chips; i++) {
-		pdata.index = index++;
-		pdata.base = gpio_mockup_range_base(i);
-		pdata.ngpio = pdata.base < 0
-				? gpio_mockup_range_ngpio(i)
-				: gpio_mockup_range_ngpio(i) - pdata.base;
-		pdata.named_lines = gpio_mockup_named_lines;
-
-		pdev = platform_device_register_resndata(NULL,
-							 GPIO_MOCKUP_NAME,
-							 i, NULL, 0, &pdata,
-							 sizeof(pdata));
+		memset(properties, 0, sizeof(properties));
+		memset(&pdevinfo, 0, sizeof(pdevinfo));
+		prop = 0;
+
+		base = gpio_mockup_range_base(i);
+		if (base >= 0)
+			properties[prop++] = PROPERTY_ENTRY_U32("gpio-base",
+								base);
+
+		ngpio = base < 0 ? gpio_mockup_range_ngpio(i)
+				 : gpio_mockup_range_ngpio(i) - base;
+		properties[prop++] = PROPERTY_ENTRY_U16("nr-gpios", ngpio);
+
+		if (gpio_mockup_named_lines)
+			properties[prop++] = PROPERTY_ENTRY_BOOL(
+						"named-gpio-lines");
+
+		pdevinfo.name = GPIO_MOCKUP_NAME;
+		pdevinfo.id = i;
+		pdevinfo.properties = properties;
+
+		pdev = platform_device_register_full(&pdevinfo);
 		if (IS_ERR(pdev)) {
 			gpio_mockup_err("error registering device");
 			platform_driver_unregister(&gpio_mockup_driver);
Signature · 1 line
2.18.0
#1 lore raw
Quoted 6 lines · Bartosz Golaszewski

Some users want to introduce device tree support to the mockup driver. Let's make it easier by switching to using generic device properties. The driver stays compatible with previous use cases and after this conversion there'll be no need to change the way probing of mockup GPIO chips works.

Quoted 6 lines

Tested with libgpiod test suite.

---
v1 -> v2:
- dropped an unnecessary check when reading the base gpio number property

Patch applied.

Vincent, could you rebase your work on top of this when/if you resend?

Yours,
Linus Walleij