pinctrl: imx: fix NO_PAD_CTL setting for MMIO pads

After patch b96eea71 ("pinctrl: fsl: add scu based pinctrl support"),
NO_PAD_CTL pads map are not skipped anymore which results in
a possible memory corruption. As we actually only need to create config
maps for SCU pads and MMIO pads which are not using the default config
(a.k.a IMX_NO_PAD_CTL), so let's add a proper check before creating
the config maps. And during MMIO pads parsing, we also need update the
list_p point as SCU case to ensure the pin data next parsed is correct.

Cc: Linus Walleij <linus.walleij@linaro.org>
Fixes: b96eea71 ("pinctrl: fsl: add scu based pinctrl support")
Reported-by: Martin Kaiser <martin@kaiser.cx>
Suggested-by: Leonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Reviewed-by: Martin Kaiser <martin@kaiser.cx>
Tested-by: Leonard Crestez <leonard.crestez@nxp.com>
Tested-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/freescale/pinctrl-imx.c

@@ -108,6 +108,15 @@ static int imx_dt_node_to_map(struct pinctrl_dev *pctldev,
 	new_map++;
 	for (i = j = 0; i < grp->num_pins; i++) {
 		pin = &((struct imx_pin *)(grp->data))[i];
+
+		/*
+		 * We only create config maps for SCU pads or MMIO pads that
+		 * are not using the default config(a.k.a IMX_NO_PAD_CTL)
+		 */
+		if (!(info->flags & IMX_USE_SCU) &&
+		    (pin->conf.mmio.config & IMX_NO_PAD_CTL))
+			continue;
+
 		new_map[j].type = PIN_MAP_TYPE_CONFIGS_PIN;
 		new_map[j].data.configs.group_or_pin =
 					pin_get_name(pctldev, pin->pin);
@@ -120,7 +129,7 @@ static int imx_dt_node_to_map(struct pinctrl_dev *pctldev,
 			new_map[j].data.configs.configs =
 					(unsigned long *)&pin->conf.scu;
 			new_map[j].data.configs.num_configs = 2;
-		} else if (!(pin->conf.mmio.config & IMX_NO_PAD_CTL)) {
+		} else {
 			new_map[j].data.configs.configs =
 					&pin->conf.mmio.config;
 			new_map[j].data.configs.num_configs = 1;
@@ -549,6 +558,8 @@ static void imx_pinctrl_parse_pin_mmio(struct imx_pinctrl *ipctl,
 		pin_mmio->config = config & ~IMX_PAD_SION;
 	}
 
+	*list_p = list;
+
 	dev_dbg(ipctl->dev, "%s: 0x%x 0x%08lx", info->pins[*pin_id].name,
 			     pin_mmio->mux_mode, pin_mmio->config);
 }