mmc: pwrseq_simple: Make reset-gpios optional to match doc

The DT binding doc says reset-gpios is an optional property but the code currently bails out if it is omitted.

This is a regression since it breaks previously working device trees. Fix it by restoring the original documented behaviour.

Fixes ce037275861e ("mmc: pwrseq_simple: use GPIO descriptors array API")

Tested-by Tony Lindgren <[email protected]>

Signed-off-by Martin Fuzzey <[email protected]>

---
V2:
Fix review comments by Ulf Hansson:
* Handle -ENOSYS case when CONFIG_GPIOLIB not selected This causes checkpatch to complain with
"WARNING: ENOSYS means 'invalid syscall nr' and nothing else"
but I guess that's ok here.
* Update patch description to make it clear this is a regression fix
* Add Fixes tag

Add Tested-by tag from Tony Lingdren

---
 drivers/mmc/core/pwrseq_simple.c |   22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

drivers/mmc/core/pwrseq_simple.c +14 -8

index d10538b..96f45ca 100644
@@ -29,15 +29,18 @@ struct mmc_pwrseq_simple {
 static void mmc_pwrseq_simple_set_gpios_value(struct mmc_pwrseq_simple *pwrseq,
                                              int value)
 {
-       int i;
        struct gpio_descs *reset_gpios = pwrseq->reset_gpios;
-       int values[reset_gpios->ndescs];
 
-       for (i = 0; i < reset_gpios->ndescs; i++)
-               values[i] = value;
+       if (!IS_ERR(reset_gpios)) {
+               int i;
+               int values[reset_gpios->ndescs];
 
-       gpiod_set_array_value_cansleep(reset_gpios->ndescs, reset_gpios->desc,
-                                      values);
+               for (i = 0; i < reset_gpios->ndescs; i++)
+                       values[i] = value;
+
+               gpiod_set_array_value_cansleep(
+                       reset_gpios->ndescs, reset_gpios->desc, values);
+       }
 }
 
 static void mmc_pwrseq_simple_pre_power_on(struct mmc_host *host)

@@ -79,7 +82,8 @@ static void mmc_pwrseq_simple_free(struct mmc_host *host)
        struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
                                        struct mmc_pwrseq_simple, pwrseq);
 
-       gpiod_put_array(pwrseq->reset_gpios);
+       if (!IS_ERR(pwrseq->reset_gpios))
+               gpiod_put_array(pwrseq->reset_gpios);
 
        if (!IS_ERR(pwrseq->ext_clk))
                clk_put(pwrseq->ext_clk);

@@ -112,7 +116,9 @@ struct mmc_pwrseq *mmc_pwrseq_simple_alloc(struct mmc_host *host,
        }
 
        pwrseq->reset_gpios = gpiod_get_array(dev, "reset", GPIOD_OUT_HIGH);
-       if (IS_ERR(pwrseq->reset_gpios)) {
+       if (IS_ERR(pwrseq->reset_gpios) &&
+           PTR_ERR(pwrseq->reset_gpios) != -ENOENT &&
+           PTR_ERR(pwrseq->reset_gpios) != -ENOSYS) {
                ret = PTR_ERR(pwrseq->reset_gpios);
                goto clk_put;
        }