pinctrl: samsung: add pin_dbg_show callback for debugfs

This patch adds a samsung_pin_dbg_show function to implement the
pin_dbg_show callback function which can be used to show pin
confuration values. Basically, it can show pin setting values by
accessing the "pins" node like below:

$ cat pins
pin 0 (gpy7-0)  CON(0x0) DAT(0x1) PUD(0x1) DRV(0x0) CON_PDN(0x0) PUD_PDN(0x0)

Signed-off-by: Chanho Park <parkch98@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Tested-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/pinctrl/samsung/pinctrl-samsung.c b/drivers/pinctrl/samsung/pinctrl-samsung.c
index 336e88d7bdb9bbe69496c25cc510007aec858cc3..618945a0fd3807dee68486f9d8c206c03c068ab2 100644 (file)
--- a/drivers/pinctrl/samsung/pinctrl-samsung.c
+++ b/drivers/pinctrl/samsung/pinctrl-samsung.c
@@ -279,6 +279,32 @@ static int samsung_dt_node_to_map(struct pinctrl_dev *pctldev,
        return 0;
 }
 
+#ifdef CONFIG_DEBUG_FS
+/* Forward declaration which can be used by samsung_pin_dbg_show */
+static int samsung_pinconf_get(struct pinctrl_dev *pctldev, unsigned int pin,
+                                       unsigned long *config);
+static const char * const reg_names[] = {"CON", "DAT", "PUD", "DRV", "CON_PDN",
+                                        "PUD_PDN"};
+
+static void samsung_pin_dbg_show(struct pinctrl_dev *pctldev,
+                               struct seq_file *s, unsigned int pin)
+{
+       enum pincfg_type cfg_type;
+       unsigned long config;
+       int ret;
+
+       for (cfg_type = 0; cfg_type < PINCFG_TYPE_NUM; cfg_type++) {
+               config = PINCFG_PACK(cfg_type, 0);
+               ret = samsung_pinconf_get(pctldev, pin, &config);
+               if (ret < 0)
+                       continue;
+
+               seq_printf(s, " %s(0x%lx)", reg_names[cfg_type],
+                          PINCFG_UNPACK_VALUE(config));
+       }
+}
+#endif
+
 /* list of pinctrl callbacks for the pinctrl core */
 static const struct pinctrl_ops samsung_pctrl_ops = {
        .get_groups_count       = samsung_get_group_count,
@@ -286,6 +312,9 @@ static const struct pinctrl_ops samsung_pctrl_ops = {
        .get_group_pins         = samsung_get_group_pins,
        .dt_node_to_map         = samsung_dt_node_to_map,
        .dt_free_map            = samsung_dt_free_map,
+#ifdef CONFIG_DEBUG_FS
+       .pin_dbg_show           = samsung_pin_dbg_show,
+#endif
 };
 
 /* check if the selector is a valid pin function selector */