pinctrl: at91: implement at91_pinconf_dbg_show

This allows to get the pin configuration by using debugfs. On my system:
 # cat /sys/kernel/debug/pinctrl/pinctrl.3/pinconf-pins

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 25 insertions, 0 deletions

diff --git a/drivers/pinctrl/pinctrl-at91.c b/drivers/pinctrl/pinctrl-at91.c
index b0b78f3468ae..bcfc8a2eebca 100644
--- a/drivers/pinctrl/pinctrl-at91.c
+++ b/drivers/pinctrl/pinctrl-at91.c
@@ -784,10 +784,35 @@ static int at91_pinconf_set(struct pinctrl_dev *pctldev,
         return 0;
 }
 
+#define DBG_SHOW_FLAG(flag) do {                \
+        if (config & flag) {                    \
+                if (num_conf)                   \
+                        seq_puts(s, "|");       \
+                seq_puts(s, #flag);             \
+                num_conf++;                     \
+        }                                       \
+} while (0)
+
 static void at91_pinconf_dbg_show(struct pinctrl_dev *pctldev,
                                    struct seq_file *s, unsigned pin_id)
 {
+        unsigned long config;
+        int ret, val, num_conf = 0;
+
+        ret = at91_pinconf_get(pctldev, pin_id, &config);
+
+        DBG_SHOW_FLAG(MULTI_DRIVE);
+        DBG_SHOW_FLAG(PULL_UP);
+        DBG_SHOW_FLAG(PULL_DOWN);
+        DBG_SHOW_FLAG(DIS_SCHMIT);
+        DBG_SHOW_FLAG(DEGLITCH);
+        DBG_SHOW_FLAG(DEBOUNCE);
+        if (config & DEBOUNCE) {
+                val = config >> DEBOUNCE_VAL_SHIFT;
+                seq_printf(s, "(%d)", val);
+        }
 
+        return;
 }
 
 static void at91_pinconf_group_dbg_show(struct pinctrl_dev *pctldev,