pinctrl: amd: print debounce filter info in debugfs

Print the status of debounce filter as follows,

$ cat /sys/kernel/debug/gpio
pin129 interrupt is disabled | interrupt is masked |
  disable wakeup in S0i3 state | disable wakeup in S3 state |
  disable wakeup in S4/S5 state| input is high | pull-up is disabled |
  Pull-down is disabled | output is disabled |
  debouncing filter disabled | 0x50000

pin130 interrupt is disabled | interrupt is masked |
  disable wakeup in S0i3 state | disable wakeup in S3 state |
  disable wakeup in S4/S5 state | input is high | pull-up is disabled |
  Pull-down is disabled | output is disabled |
  debouncing filter (high) enabled |
  debouncing timeout is 124800 (us)| 0x503c8
Signed-off-by: Coiby Xu <coiby.xu@gmail.com>
Link: https://lore.kernel.org/r/20201105231912.69527-4-coiby.xu@gmail.comSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinctrl-amd.c

@@ -197,10 +197,16 @@ static int amd_gpio_set_config(struct gpio_chip *gc, unsigned offset,
 static void amd_gpio_dbg_show(struct seq_file *s, struct gpio_chip *gc)
 {
 	u32 pin_reg;
+	u32 db_cntrl;
 	unsigned long flags;
 	unsigned int bank, i, pin_num;
 	struct amd_gpio *gpio_dev = gpiochip_get_data(gc);
 
+	bool tmr_out_unit;
+	unsigned int time;
+	unsigned int unit;
+	bool tmr_large;
+
 	char *level_trig;
 	char *active_level;
 	char *interrupt_enable;
@@ -214,6 +220,8 @@ static void amd_gpio_dbg_show(struct seq_file *s, struct gpio_chip *gc)
 	char *pull_down_enable;
 	char *output_value;
 	char *output_enable;
+	char debounce_value[40];
+	char *debounce_enable;
 
 	for (bank = 0; bank < gpio_dev->hwbank_num; bank++) {
 		seq_printf(s, "GPIO bank%d\t", bank);
@@ -327,13 +335,44 @@ static void amd_gpio_dbg_show(struct seq_file *s, struct gpio_chip *gc)
 					pin_sts = "input is low|";
 			}
 
+			db_cntrl = (DB_CNTRl_MASK << DB_CNTRL_OFF) & pin_reg;
+			if (db_cntrl) {
+				tmr_out_unit = pin_reg & BIT(DB_TMR_OUT_UNIT_OFF);
+				tmr_large = pin_reg & BIT(DB_TMR_LARGE_OFF);
+				time = pin_reg & DB_TMR_OUT_MASK;
+				if (tmr_large) {
+					if (tmr_out_unit)
+						unit = 62500;
+					else
+						unit = 15625;
+				} else {
+					if (tmr_out_unit)
+						unit = 244;
+					else
+						unit = 61;
+				}
+				if ((DB_TYPE_REMOVE_GLITCH << DB_CNTRL_OFF) == db_cntrl)
+					debounce_enable = "debouncing filter (high and low) enabled|";
+				else if ((DB_TYPE_PRESERVE_LOW_GLITCH << DB_CNTRL_OFF) == db_cntrl)
+					debounce_enable = "debouncing filter (low) enabled|";
+				else
+					debounce_enable = "debouncing filter (high) enabled|";
+
+				snprintf(debounce_value, sizeof(debounce_value),
+					 "debouncing timeout is %u (us)|", time * unit);
+			} else {
+				debounce_enable = "debouncing filter disabled|";
+				snprintf(debounce_value, sizeof(debounce_value), " ");
+			}
+
 			seq_printf(s, "%s %s %s %s %s %s\n"
-				" %s %s %s %s %s %s %s 0x%x\n",
+				" %s %s %s %s %s %s %s %s %s 0x%x\n",
 				level_trig, active_level, interrupt_enable,
 				interrupt_mask, wake_cntrl0, wake_cntrl1,
 				wake_cntrl2, pin_sts, pull_up_sel,
 				pull_up_enable, pull_down_enable,
-				output_value, output_enable, pin_reg);
+				output_value, output_enable,
+				debounce_enable, debounce_value, pin_reg);
 		}
 	}
 }