[PATCH v2] pinctrl: core: print gpio in pins debugfs file

[Drew Fustini <drew@xxxxxxxxxxxxxxx>]

If there is a gpio range mapping for the pin, then print out the gpio
number for the pin in the debugfs 'pins' file.

Here is an example output on the BeagleBone Black from:
/sys/kernel/debug/pinctrl/44e10800.pinmux-pinctrl-single/pins

pin 100 (PIN100) gpiochip:gpio-96-127 line-name:P1.36 [PWM0A] 44e10990 00000001 pinctrl-single 
pin 101 (PIN101) gpiochip:gpio-96-127 line-name:P1.33 [PRU0.1] 44e10994 00000027 pinctrl-single 
pin 102 (PIN102) gpiochip:gpio-96-127 line-name:P2.32 [PRU0.2] 44e10998 00000027 pinctrl-single 
pin 103 (PIN103) gpiochip:gpio-96-127 line-name:P2.30 [PRU0.3] 44e1099c 00000027 pinctrl-single 
pin 104 (PIN104) gpiochip:gpio-96-127 line-name:P1.31 [PRU0.4] 44e109a0 0000002c pinctrl-single 
pin 105 (PIN105) gpiochip:gpio-96-127 line-name:P2.34 [PRU0.5] 44e109a4 00000027 pinctrl-single 
pin 106 (PIN106) gpiochip:gpio-96-127 line-name:P2.28 [PRU0.6] 44e109a8 00000027 pinctrl-single 
pin 107 (PIN107) gpiochip:gpio-96-127 line-name:P1.29 [PRU0.7] 44e109ac 00000027 pinctrl-single 
pin 108 (PIN108) gpiochip:gpio-0-31 line-name:P2.31 [SPI1_CS] 44e109b0 00000027 pinctrl-single 
pin 109 (PIN109) gpiochip:gpio-0-31 line-name:P1.20 [PRU0.16] 44e109b4 00000027 pinctrl-single 
pin 110 (PIN110) NA 44e109b8 00000030 pinctrl-single 
pin 111 (PIN111) NA 44e109bc 00000028 pinctrl-single 
pin 112 (PIN112) NA 44e109c0 00000030 pinctrl-single 
pin 113 (PIN113) NA 44e109c4 00000028 pinctrl-single 
pin 114 (PIN114) NA 44e109c8 00000028 pinctrl-single 
pin 115 (PIN115) NA 44e109cc 00000028 pinctrl-single 

Suggested-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
Suggested-by: Tony Lindgren <tony@xxxxxxxxxxx>
Signed-off-by: Drew Fustini <drew@xxxxxxxxxxxxxxx>
---
 drivers/pinctrl/core.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

v2 changes:
- only include GPIO information if CONFIG_GPIOLIB
- print gpiochip and line name instead of global GPIO number

diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index 821242bb4b16..b61fab96c5c2 100644
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -27,6 +27,7 @@
 #include <linux/pinctrl/machine.h>
 
 #ifdef CONFIG_GPIOLIB
+#include "../gpio/gpiolib.h"
 #include <asm-generic/gpio.h>
 #endif
 
@@ -1601,6 +1602,11 @@ static int pinctrl_pins_show(struct seq_file *s, void *what)
 	struct pinctrl_dev *pctldev = s->private;
 	const struct pinctrl_ops *ops = pctldev->desc->pctlops;
 	unsigned i, pin;
+	struct pinctrl_gpio_range *range;
+	unsigned int gpio_num;
+	struct gpio_chip *chip;
+	struct gpio_desc *gdesc;
+
 
 	seq_printf(s, "registered pins: %d\n", pctldev->desc->npins);
 
@@ -1618,6 +1624,30 @@ static int pinctrl_pins_show(struct seq_file *s, void *what)
 
 		seq_printf(s, "pin %d (%s) ", pin, desc->name);
 
+#ifdef CONFIG_GPIOLIB
+		gpio_num = 0;
+		list_for_each_entry(range, &pctldev->gpio_ranges, node) {
+			if ((pin >= range->pin_base) &&
+			    (pin < (range->pin_base + range->npins))) {
+				gpio_num = range->base + (pin - range->pin_base);
+				break;
+			}
+		}
+		if (gpio_num > 0) {
+			chip = gpio_to_chip(gpio_num);
+			if (chip != NULL) {
+				if (chip->label)
+					seq_printf(s, "gpiochip:%s ", chip->label);
+			}
+			gdesc = gpio_to_desc(gpio_num);
+			if (gdesc != NULL)
+				if (gdesc->name)
+					seq_printf(s, "line-name:%s ", gdesc->name);
+		} else {
+			seq_puts(s, "NA ");
+		}
+#endif
+
 		/* Driver-specific info per pin */
 		if (ops->pin_dbg_show)
 			ops->pin_dbg_show(pctldev, s, pin);
-- 
2.25.1