mmc: pwrseq_simple: Handle !RESET_CONTROLLER properly

The recent introduction of reset control in pwrseq_simple introduced
a regression for platforms without RESET_CONTROLLER support, because
devm_reset_control_get_optional_shared() would return NULL and make all
resets no-ops. Instead of enforcing this dependency, rely on this behavior
to determine reset support. As a benefit we can get the rid of the
use_reset flag.

Fixes: 73bf4b7381f7 ("mmc: pwrseq_simple: add support for one reset control")
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Message-ID: <20241108130647.8281-1-wahrenst@gmx.net>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/core/pwrseq_simple.c b/drivers/mmc/core/pwrseq_simple.c
index 24e4e63..37cd858 100644 (file)
--- a/drivers/mmc/core/pwrseq_simple.c
+++ b/drivers/mmc/core/pwrseq_simple.c
@@ -32,7 +32,6 @@ struct mmc_pwrseq_simple {
        struct clk *ext_clk;
        struct gpio_descs *reset_gpios;
        struct reset_control *reset_ctrl;
-       bool use_reset;
 };
 
 #define to_pwrseq_simple(p) container_of(p, struct mmc_pwrseq_simple, pwrseq)
@@ -71,7 +70,7 @@ static void mmc_pwrseq_simple_pre_power_on(struct mmc_host *host)
                pwrseq->clk_enabled = true;
        }
 
-       if (pwrseq->use_reset) {
+       if (pwrseq->reset_ctrl) {
                reset_control_deassert(pwrseq->reset_ctrl);
                reset_control_assert(pwrseq->reset_ctrl);
        } else
@@ -82,7 +81,7 @@ static void mmc_pwrseq_simple_post_power_on(struct mmc_host *host)
 {
        struct mmc_pwrseq_simple *pwrseq = to_pwrseq_simple(host->pwrseq);
 
-       if (pwrseq->use_reset)
+       if (pwrseq->reset_ctrl)
                reset_control_deassert(pwrseq->reset_ctrl);
        else
                mmc_pwrseq_simple_set_gpios_value(pwrseq, 0);
@@ -95,7 +94,7 @@ static void mmc_pwrseq_simple_power_off(struct mmc_host *host)
 {
        struct mmc_pwrseq_simple *pwrseq = to_pwrseq_simple(host->pwrseq);
 
-       if (pwrseq->use_reset)
+       if (pwrseq->reset_ctrl)
                reset_control_assert(pwrseq->reset_ctrl);
        else
                mmc_pwrseq_simple_set_gpios_value(pwrseq, 1);
@@ -137,15 +136,18 @@ static int mmc_pwrseq_simple_probe(struct platform_device *pdev)
                return dev_err_probe(dev, PTR_ERR(pwrseq->ext_clk), "external clock not ready\n");
 
        ngpio = of_count_phandle_with_args(dev->of_node, "reset-gpios", "#gpio-cells");
-       if (ngpio == 1)
-               pwrseq->use_reset = true;
-
-       if (pwrseq->use_reset) {
+       if (ngpio == 1) {
                pwrseq->reset_ctrl = devm_reset_control_get_optional_shared(dev, NULL);
                if (IS_ERR(pwrseq->reset_ctrl))
                        return dev_err_probe(dev, PTR_ERR(pwrseq->reset_ctrl),
                                             "reset control not ready\n");
-       } else {
+       }
+
+       /*
+        * Fallback to GPIO based reset control in case of multiple reset lines
+        * are specified or the platform doesn't have support for RESET at all.
+        */
+       if (!pwrseq->reset_ctrl) {
                pwrseq->reset_gpios = devm_gpiod_get_array(dev, "reset", GPIOD_OUT_HIGH);
                if (IS_ERR(pwrseq->reset_gpios) &&
                    PTR_ERR(pwrseq->reset_gpios) != -ENOENT &&