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authorLinus Walleij <linus.walleij@linaro.org>2016-02-12 14:48:23 +0100
committerLinus Walleij <linus.walleij@linaro.org>2016-02-19 09:48:41 +0100
commitdf4878e969ccc047da45d2cd3af5d08031da1593 (patch)
tree2677387492b60fd5c6a42a317bde0e7e965aa8fa
parent0a7439ef755d46a2e61d460d7a440f7fa65d7182 (diff)
gpio: store reflect the label to userspace
The gpio_chip label is useful for userspace to understand what kind of GPIO chip it is dealing with. Let's store a copy of this label in the gpio_device, add it to the struct passed to userspace for GPIO_GET_CHIPINFO_IOCTL and modify lsgpio to show it. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
-rw-r--r--drivers/gpio/gpiolib.c13
-rw-r--r--drivers/gpio/gpiolib.h3
-rw-r--r--include/linux/gpio/driver.h3
-rw-r--r--include/uapi/linux/gpio.h2
-rw-r--r--tools/gpio/lsgpio.c4
5 files changed, 22 insertions, 3 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 59f0045c5950..797c790aa750 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -342,6 +342,9 @@ static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
strncpy(chipinfo.name, dev_name(&gdev->dev),
sizeof(chipinfo.name));
chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
+ strncpy(chipinfo.label, gdev->label,
+ sizeof(chipinfo.label));
+ chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
chipinfo.lines = gdev->ngpio;
if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
return -EFAULT;
@@ -479,6 +482,16 @@ int gpiochip_add_data(struct gpio_chip *chip, void *data)
status = -EINVAL;
goto err_free_gdev;
}
+
+ if (chip->label)
+ gdev->label = devm_kstrdup(&gdev->dev, chip->label, GFP_KERNEL);
+ else
+ gdev->label = devm_kstrdup(&gdev->dev, "unknown", GFP_KERNEL);
+ if (!gdev->label) {
+ status = -ENOMEM;
+ goto err_free_gdev;
+ }
+
gdev->ngpio = chip->ngpio;
gdev->data = data;
diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h
index ddbe409ad48f..e30e5fdb1214 100644
--- a/drivers/gpio/gpiolib.h
+++ b/drivers/gpio/gpiolib.h
@@ -37,6 +37,8 @@ struct acpi_device;
* of the @descs array.
* @base: GPIO base in the DEPRECATED global Linux GPIO numberspace, assigned
* at device creation time.
+ * @label: a descriptive name for the GPIO device, such as the part number
+ * or name of the IP component in a System on Chip.
* @data: per-instance data assigned by the driver
* @list: links gpio_device:s together for traversal
*
@@ -55,6 +57,7 @@ struct gpio_device {
struct gpio_desc *descs;
int base;
u16 ngpio;
+ char *label;
void *data;
struct list_head list;
diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index ff96d0f9fceb..639607658ed8 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -21,7 +21,8 @@ struct gpio_device;
/**
* struct gpio_chip - abstract a GPIO controller
- * @label: for diagnostics
+ * @label: a functional name for the GPIO device, such as a part
+ * number or the name of the SoC IP-block implementing it.
* @gpiodev: the internal state holder, opaque struct
* @parent: optional parent device providing the GPIOs
* @owner: helps prevent removal of modules exporting active GPIOs
diff --git a/include/uapi/linux/gpio.h b/include/uapi/linux/gpio.h
index 3188a87bdaa0..3f93e1bcd3dd 100644
--- a/include/uapi/linux/gpio.h
+++ b/include/uapi/linux/gpio.h
@@ -16,10 +16,12 @@
/**
* struct gpiochip_info - Information about a certain GPIO chip
* @name: the name of this GPIO chip
+ * @label: a functional name for this GPIO chip
* @lines: number of GPIO lines on this chip
*/
struct gpiochip_info {
char name[32];
+ char label[32];
__u32 lines;
};
diff --git a/tools/gpio/lsgpio.c b/tools/gpio/lsgpio.c
index 4cfe29da279b..692233f561fb 100644
--- a/tools/gpio/lsgpio.c
+++ b/tools/gpio/lsgpio.c
@@ -54,8 +54,8 @@ int list_device(const char *device_name)
goto free_chrdev_name;
}
- fprintf(stdout, "GPIO chip: %s, %u GPIO lines\n",
- cinfo.name, cinfo.lines);
+ fprintf(stdout, "GPIO chip: %s, \"%s\", %u GPIO lines\n",
+ cinfo.name, cinfo.label, cinfo.lines);
if (close(fd) == -1) {
ret = -errno;