[PATCH v3 1/2] pinctrl: renesas: Make sure the pin type is updated after setting the MUX

[Lad Prabhakar]

By default on startup all the pin types are configured to
PINMUX_TYPE_NONE (in sh_pfc_map_pins()), when pin is set as GPIO the
pin type is updated to PINMUX_TYPE_GPIO. But the type is not updated
when the pin is set as a function in sh_pfc_pinctrl_pin_set() or
sh_pfc_pinctrl_group_set() calls (these calls only set the MUX if
the pin type is PINMUX_TYPE_NONE ie unused).

So with the current implementation pin functionality could be overwritten
silently, for example if the same pin is added for SPI and serial.

This patch makes sure of updating pin type after every successful call to
sh_pfc_config_mux() and thus fixing from pin functionality to be
overwritten. Also a warning message is printed if the current pin is being
overwritten before abort.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj at bp.renesas.com>
Reviewed-by: Biju Das <biju.das.jz at bp.renesas.com>
---
 drivers/pinctrl/renesas/pfc.c | 28 +++++++++++++++++++++++-----
 1 file changed, 23 insertions(+), 5 deletions(-)

diff --git a/drivers/pinctrl/renesas/pfc.c b/drivers/pinctrl/renesas/pfc.c
index fb811a95bc..174e91923a 100644
--- a/drivers/pinctrl/renesas/pfc.c
+++ b/drivers/pinctrl/renesas/pfc.c
@@ -487,8 +487,10 @@ static int sh_pfc_gpio_request_enable(struct udevice *dev,
 	idx = sh_pfc_get_pin_index(pfc, pin->pin);
 	cfg = &pmx->configs[idx];
 
-	if (cfg->type != PINMUX_TYPE_NONE)
+	if (cfg->type != PINMUX_TYPE_NONE) {
+		dev_err(pfc->dev, "Pin already used\n");
 		return -EBUSY;
+	}
 
 	ret = sh_pfc_config_mux(pfc, pin->enum_id, PINMUX_TYPE_GPIO);
 	if (ret)
@@ -537,11 +539,20 @@ static int sh_pfc_pinctrl_pin_set(struct udevice *dev, unsigned pin_selector,
 	const struct sh_pfc_pin *pin = &priv->pfc.info->pins[pin_selector];
 	int idx = sh_pfc_get_pin_index(pfc, pin->pin);
 	struct sh_pfc_pin_config *cfg = &pmx->configs[idx];
+	int ret;
 
-	if (cfg->type != PINMUX_TYPE_NONE)
+	if (cfg->type != PINMUX_TYPE_NONE) {
+		dev_err(pfc->dev, "Pin already used\n");
 		return -EBUSY;
+	}
+
+	ret = sh_pfc_config_mux(pfc, pin->enum_id, PINMUX_TYPE_FUNCTION);
+	if (ret)
+		return ret;
 
-	return sh_pfc_config_mux(pfc, pin->enum_id, PINMUX_TYPE_FUNCTION);
+	cfg->type = PINMUX_TYPE_FUNCTION;
+
+	return 0;
 }
 
 static int sh_pfc_pinctrl_group_set(struct udevice *dev, unsigned group_selector,
@@ -551,14 +562,17 @@ static int sh_pfc_pinctrl_group_set(struct udevice *dev, unsigned group_selector
 	struct sh_pfc_pinctrl *pmx = &priv->pmx;
 	struct sh_pfc *pfc = &priv->pfc;
 	const struct sh_pfc_pin_group *grp = &priv->pfc.info->groups[group_selector];
+	struct sh_pfc_pin_config *cfg;
 	unsigned int i;
 	int ret = 0;
+	int idx;
 
 	for (i = 0; i < grp->nr_pins; ++i) {
-		int idx = sh_pfc_get_pin_index(pfc, grp->pins[i]);
-		struct sh_pfc_pin_config *cfg = &pmx->configs[idx];
+		idx = sh_pfc_get_pin_index(pfc, grp->pins[i]);
+		cfg = &pmx->configs[idx];
 
 		if (cfg->type != PINMUX_TYPE_NONE) {
+			dev_err(pfc->dev, "Pin already used\n");
 			ret = -EBUSY;
 			goto done;
 		}
@@ -568,6 +582,10 @@ static int sh_pfc_pinctrl_group_set(struct udevice *dev, unsigned group_selector
 		ret = sh_pfc_config_mux(pfc, grp->mux[i], PINMUX_TYPE_FUNCTION);
 		if (ret < 0)
 			break;
+
+		idx = sh_pfc_get_pin_index(pfc, grp->pins[i]);
+		cfg = &pmx->configs[idx];
+		cfg->type = PINMUX_TYPE_FUNCTION;
 	}
 
 done:
-- 
2.17.1