pinctrl: stm32: defer probe if reset resource is not yet ready

Defer probe when pin controller reset is defined in the system resources
but not yet probed.

Signed-off-by: Etienne Carriere <etienne.carriere@st.com>
Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>
Link: https://lore.kernel.org/r/20200615125407.27632-3-alexandre.torgue@st.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/pinctrl/stm32/pinctrl-stm32.c b/drivers/pinctrl/stm32/pinctrl-stm32.c
index c15460e..162535e 100644 (file)
--- a/drivers/pinctrl/stm32/pinctrl-stm32.c
+++ b/drivers/pinctrl/stm32/pinctrl-stm32.c
@@ -84,6 +84,7 @@ struct stm32_pinctrl_group {
 struct stm32_gpio_bank {
        void __iomem *base;
        struct clk *clk;
+       struct reset_control *rstc;
        spinlock_t lock;
        struct gpio_chip gpio_chip;
        struct pinctrl_gpio_range range;
@@ -1202,13 +1203,11 @@ static int stm32_gpiolib_register_bank(struct stm32_pinctrl *pctl,
        struct of_phandle_args args;
        struct device *dev = pctl->dev;
        struct resource res;
-       struct reset_control *rstc;
        int npins = STM32_GPIO_PINS_PER_BANK;
        int bank_nr, err;
 
-       rstc = of_reset_control_get_exclusive(np, NULL);
-       if (!IS_ERR(rstc))
-               reset_control_deassert(rstc);
+       if (!IS_ERR(bank->rstc))
+               reset_control_deassert(bank->rstc);
 
        if (of_address_to_resource(np, 0, &res))
                return -ENODEV;
@@ -1516,6 +1515,11 @@ int stm32_pctl_probe(struct platform_device *pdev)
                struct stm32_gpio_bank *bank = &pctl->banks[i];
 
                if (of_property_read_bool(child, "gpio-controller")) {
+                       bank->rstc = of_reset_control_get_exclusive(child,
+                                                                   NULL);
+                       if (PTR_ERR(bank->rstc) == -EPROBE_DEFER)
+                               return -EPROBE_DEFER;
+
                        bank->clk = of_clk_get_by_name(child, NULL);
                        if (IS_ERR(bank->clk)) {
                                if (PTR_ERR(bank->clk) != -EPROBE_DEFER)