[PATCH 5/6] arm64: a37xx: pinctrl: Implement gpio_request_enable for gpio functionality

[Pali Rohár]

To automatically enable GPIO functionality of some MPP pin, it is required
to implement .gpio_request_enable and .gpio_disable_free callbacks in
pinctrl driver and set .request and .rfree callbacks in GPIO driver to
pinctrl_gpio_request / pinctrl_gpio_free functions.

Signed-off-by: Pali Rohár <p...@kernel.org>
---
 drivers/pinctrl/mvebu/pinctrl-armada-37xx.c | 50 +++++++++++++++++++--
 1 file changed, 47 insertions(+), 3 deletions(-)

diff --git a/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c 
b/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c
index d2abe67fe5be..74d915950a6e 100644
--- a/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c
+++ b/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c
@@ -280,12 +280,13 @@ static const char *armada_37xx_pmx_get_func_name(struct 
udevice *dev,
 
 static int armada_37xx_pmx_set_by_name(struct udevice *dev,
                                       const char *name,
-                                      struct armada_37xx_pin_group *grp)
+                                      struct armada_37xx_pin_group *grp,
+                                      bool warn_on_change)
 {
        struct armada_37xx_pinctrl *info = dev_get_priv(dev);
        unsigned int reg = SELECTION;
        unsigned int mask = grp->reg_mask;
-       int func, val;
+       int func, val, old_func;
 
        dev_dbg(info->dev, "enable function %s group %s\n",
                name, grp->name);
@@ -297,6 +298,18 @@ static int armada_37xx_pmx_set_by_name(struct udevice *dev,
 
        val = grp->val[func];
 
+       if (warn_on_change && val != (readl(info->base + reg) & mask)) {
+               for (old_func = 0; (old_func < NB_FUNCS) && 
grp->funcs[old_func]; old_func++) {
+                       if (grp->val[old_func] == val)
+                               break;
+               }
+               dev_warn(info->dev, "Warning: Changing MPPs %u-%u function from 
%s to %s...\n",
+                        grp->start_pin, grp->start_pin + grp->npins - 1,
+                        ((old_func < NB_FUNCS && grp->funcs[old_func]) ?
+                         grp->funcs[old_func] : "unknown"),
+                        name);
+       }
+
        clrsetbits_le32(info->base + reg, mask, val);
 
        return 0;
@@ -310,7 +323,34 @@ static int armada_37xx_pmx_group_set(struct udevice *dev,
        struct armada_37xx_pin_group *grp = &info->data->groups[group_selector];
        const char *name = info->funcs[func_selector].name;
 
-       return armada_37xx_pmx_set_by_name(dev, name, grp);
+       return armada_37xx_pmx_set_by_name(dev, name, grp, false);
+}
+
+static int armada_37xx_pmx_gpio_request_enable(struct udevice *dev, unsigned 
int selector)
+{
+       struct armada_37xx_pinctrl *info = dev_get_priv(dev);
+       int ret = -ENOTSUPP;
+       int n;
+
+       /* Find all groups where is requested selector pin and set each group 
to gpio function */
+       for (n = 0; n < info->data->ngroups; n++) {
+               struct armada_37xx_pin_group *grp = &info->data->groups[n];
+
+               if ((selector >= grp->start_pin && selector < grp->start_pin + 
grp->npins) ||
+                   (selector >= grp->extra_pin && selector < grp->extra_pin + 
grp->extra_npins)) {
+                       ret = armada_37xx_pmx_set_by_name(dev, "gpio", grp, 
true);
+                       if (ret)
+                               return ret;
+               }
+       }
+
+       return ret;
+}
+
+static int armada_37xx_pmx_gpio_disable_free(struct udevice *dev, unsigned int 
selector)
+{
+       /* nothing to do */
+       return 0;
 }
 
 /**
@@ -520,6 +560,8 @@ static int armada_37xx_gpio_probe(struct udevice *dev)
 }
 
 static const struct dm_gpio_ops armada_37xx_gpio_ops = {
+       .request = pinctrl_gpio_request,
+       .rfree = pinctrl_gpio_free,
        .set_value = armada_37xx_gpio_set,
        .get_value = armada_37xx_gpio_get,
        .get_function = armada_37xx_gpio_get_direction,
@@ -578,6 +620,8 @@ static const struct pinctrl_ops armada_37xx_pinctrl_ops  = {
        .get_functions_count = armada_37xx_pmx_get_funcs_count,
        .get_function_name = armada_37xx_pmx_get_func_name,
        .pinmux_group_set = armada_37xx_pmx_group_set,
+       .gpio_request_enable = armada_37xx_pmx_gpio_request_enable,
+       .gpio_disable_free = armada_37xx_pmx_gpio_disable_free,
        .set_state = pinctrl_generic_set_state,
 };
 
-- 
2.20.1