diff options
| -rw-r--r-- | drivers/gpio/gpiolib.c | 32 | ||||
| -rw-r--r-- | include/linux/gpio/driver.h | 4 |
2 files changed, 31 insertions, 5 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 27c07108496d..d1b9b721218f 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -382,10 +382,18 @@ static int devprop_gpiochip_set_names(struct gpio_chip *chip) if (count < 0) return 0; - if (count > gdev->ngpio) { - dev_warn(&gdev->dev, "gpio-line-names is length %d but should be at most length %d", - count, gdev->ngpio); - count = gdev->ngpio; + /* + * When offset is set in the driver side we assume the driver internally + * is using more than one gpiochip per the same device. We have to stop + * setting friendly names if the specified ones with 'gpio-line-names' + * are less than the offset in the device itself. This means all the + * lines are not present for every single pin within all the internal + * gpiochips. + */ + if (count <= chip->offset) { + dev_warn(&gdev->dev, "gpio-line-names too short (length %d), cannot map names for the gpiochip at offset %u\n", + count, chip->offset); + return 0; } names = kcalloc(count, sizeof(*names), GFP_KERNEL); @@ -400,8 +408,22 @@ static int devprop_gpiochip_set_names(struct gpio_chip *chip) return ret; } + /* + * When more that one gpiochip per device is used, 'count' can + * contain at most number gpiochips x chip->ngpio. We have to + * correctly distribute all defined lines taking into account + * chip->offset as starting point from where we will assign + * the names to pins from the 'names' array. Since property + * 'gpio-line-names' cannot contains gaps, we have to be sure + * we only assign those pins that really exists since chip->ngpio + * can be different of the chip->offset. + */ + count = (count > chip->offset) ? count - chip->offset : count; + if (count > chip->ngpio) + count = chip->ngpio; + for (i = 0; i < count; i++) - gdev->descs[i].name = names[i]; + gdev->descs[i].name = names[chip->offset + i]; kfree(names); diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index 3a268781fcec..a0f9901dcae6 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -312,6 +312,9 @@ struct gpio_irq_chip { * get rid of the static GPIO number space in the long run. * @ngpio: the number of GPIOs handled by this controller; the last GPIO * handled is (base + ngpio - 1). + * @offset: when multiple gpio chips belong to the same device this + * can be used as offset within the device so friendly names can + * be properly assigned. * @names: if set, must be an array of strings to use as alternative * names for the GPIOs in this chip. Any entry in the array * may be NULL if there is no alias for the GPIO, however the @@ -398,6 +401,7 @@ struct gpio_chip { int base; u16 ngpio; + u16 offset; const char *const *names; bool can_sleep; |