pinctrl: st: Display pin's function when printing pinctrl debug information

Great for easily determining which mode a pin is operating in.
This patch was particularly helpful when debugging a recent GPIO/
Pinctrl disparity issue.

Before:
    $ cat /sys/kernel/debug/pinctrl/<pin-controller>/pinconf-pins
      pin 33 (PIO4[1]):[OE:0,PU:0,OD:0]
             [retime:0,invclk:0,clknotdat:0,de:0,rt-clk:0,rt-delay:0]

After [GPIO]:
    $ cat /sys/kernel/debug/pinctrl/<pin-controller>/pinconf-pins
      pin 33 (PIO4[1]):[OE:0,PU:0,OD:0] GPIO
             [retime:0,invclk:0,clknotdat:0,de:0,rt-clk:0,rt-delay:0]

After [Alt]:
    $ cat /sys/kernel/debug/pinctrl/<pin-controller>/pinconf-pins
      pin 33 (PIO4[1]):[OE:0,PU:0,OD:0] Alt Fn 2
             [retime:0,invclk:0,clknotdat:0,de:0,rt-clk:0,rt-delay:0]

Acked-by: Maxime Coquelin <maxime.coquelin@st.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/pinctrl/pinctrl-st.c b/drivers/pinctrl/pinctrl-st.c
index 1cda40e013c1c56be1bb962c0671c53814d9dc5e..b80ccc74a213f4b4889bb6d5963bca329cb6162d 100644 (file)
--- a/drivers/pinctrl/pinctrl-st.c
+++ b/drivers/pinctrl/pinctrl-st.c
@@ -1058,18 +1058,28 @@ static void st_pinconf_dbg_show(struct pinctrl_dev *pctldev,
 {
        struct st_pio_control *pc;
        unsigned long config;
+       unsigned int function;
        int offset = st_gpio_pin(pin_id);
+       char f[16];
 
        mutex_unlock(&pctldev->mutex);
        pc = st_get_pio_control(pctldev, pin_id);
        st_pinconf_get(pctldev, pin_id, &config);
        mutex_lock(&pctldev->mutex);
-       seq_printf(s, "[OE:%ld,PU:%ld,OD:%ld]\n"
+
+       function = st_pctl_get_pin_function(pc, offset);
+       if (function)
+               snprintf(f, 10, "Alt Fn %d", function);
+       else
+               snprintf(f, 5, "GPIO");
+
+       seq_printf(s, "[OE:%d,PU:%ld,OD:%ld]\t%s\n"
                "\t\t[retime:%ld,invclk:%ld,clknotdat:%ld,"
                "de:%ld,rt-clk:%ld,rt-delay:%ld]",
                !st_gpio_get_direction(&pc_to_bank(pc)->gpio_chip, offset),
                ST_PINCONF_UNPACK_PU(config),
                ST_PINCONF_UNPACK_OD(config),
+               f,
                ST_PINCONF_UNPACK_RT(config),
                ST_PINCONF_UNPACK_RT_INVERTCLK(config),
                ST_PINCONF_UNPACK_RT_CLKNOTDATA(config),