@@ -996,7 +996,7 @@ static int atmel_pinctrl_probe(struct platform_device *pdev)
struct pinctrl_pin_desc *pin_desc;
const char **group_names;
const struct of_device_id *match;
- int i, ret;
+ int i, ret, autoname;
struct resource *res;
struct atmel_pioctrl *atmel_pioctrl;
const struct atmel_pioctrl_data *atmel_pioctrl_data;
@@ -1056,6 +1056,7 @@ static int atmel_pinctrl_probe(struct platform_device *pdev)
GFP_KERNEL);
if (!atmel_pioctrl->groups)
return -ENOMEM;
+ autoname = !of_property_read_bool(dev->of_node, "no-autoname");
for (i = 0 ; i < atmel_pioctrl->npins; i++) {
struct atmel_group *group = atmel_pioctrl->groups + i;
unsigned bank = ATMEL_PIO_BANK(i);
@@ -1086,8 +1087,9 @@ static int atmel_pinctrl_probe(struct platform_device *pdev)
atmel_pioctrl->gpio_chip->ngpio = atmel_pioctrl->npins;
atmel_pioctrl->gpio_chip->label = dev_name(dev);
atmel_pioctrl->gpio_chip->parent = dev;
- atmel_pioctrl->gpio_chip->names = atmel_pioctrl->group_names;
-
+ if (autoname) {
+ atmel_pioctrl->gpio_chip->names = atmel_pioctrl->group_names;
+ }
atmel_pioctrl->pm_wakeup_sources = devm_kcalloc(dev,
atmel_pioctrl->nbanks,
sizeof(*atmel_pioctrl->pm_wakeup_sources),
Hi! I am working with an in-house board and getting the Kernel and Device Tree straightened out for our needs. After seeing the bold statements in the sysfs documentation regarding gpio access, I figured that you guys really mean it and decided to do things the right way. In doing so, however, I'm finding it to be unexpectedly difficult. My board is uses the sama5d27 SIP. There are certain portions of the board which require GPIO lines to be driven from user-space, and these aspects do not really fit within any particular kernel driver. For example, I need to be able to enable a CAN transceiver whenever the CAN peripheral is in use, and disable it when it is not in order to disconnect ourselves from the network. I want to be able to name this GPIO in Device Tree so that future revisions of this board have the flexibility to use a different GPIO for this task and user space does not need to know that PC31 is connected to the transceiver. The atmel pio4 driver automatically sets names for the GPIOs [1], from PA0 to PD31, and the gpiolib ignores the gpio-line-names property if the chip has already set them. [2] I worked around this by adding a "no-autoname" device tree property to the pio4 pinctrl driver. The patch is attached, but it is admittedly quick & dirty and not something I'm ready to put my name on yet. I'm still unable to use libgpiod effectively, with or without my changes, and I feel like I am fundamentally missing something. gpioinfo shows all pins as "input". Setting a pin's value makes gpioinfo show that pin as an output until I use gpioget. At this point it reverts back to an input: # gpioinfo | grep PC31 line 95: "PC31" unused input active-high # gpioset 0 95=0 # gpioinfo | grep PC31 line 95: "PC31" unused output active-high # gpioget 0 95 1 # gpioinfo | grep PC31 line 95: "PC31" unused input active-high This was tested with the following dt setup: &pioA { // no-autoname; gpio-line-names = /* PA */ "", "", "", "", "", "", "", "", "", "", "", "", "GPS_EN", "", "", "", "", "", "3V3_EN", "", "", "", "", "", "", "", "", "", "", "", "", "", /* PB */ "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", /* PC */ "GPS_RESET", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "CAN0_EN", /* PD */ "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", ""; can0-enable { gpios = <PIN_PC31 GPIO_ACTIVE_HIGH>; output-low; line-name = "CAN0_EN"; }; }; Any idea where I have gone wrong here? 1. https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/drivers/gpio/gpiolib-of.c?h=linux-5.5.y#n908 2. https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/drivers/pinctrl/pinctrl-at91-pio4.c?h=linux-5.5.y#n1089