pinctrl: tegra: error reporting cleanup

Print an explicit error message in various failure cases to allow
easier diagnosis.

WARN_ON() some internal failures that users/clients shouldn't be able to
trigger.

Signed-off-by: Stephen Warren <swarren@nvidia.com>

1 files changed, 55 insertions, 26 deletions

diff --git a/drivers/pinctrl/pinctrl-tegra.c b/drivers/pinctrl/pinctrl-tegra.c
index df52d75c0db0..b6934867d8d3 100644
--- a/drivers/pinctrl/pinctrl-tegra.c
+++ b/drivers/pinctrl/pinctrl-tegra.c
@@ -92,8 +92,9 @@ static void tegra_pinctrl_pin_dbg_show(struct pinctrl_dev *pctldev,
 }
 #endif
 
-static int reserve_map(struct pinctrl_map **map, unsigned *reserved_maps,
-                       unsigned *num_maps, unsigned reserve)
+static int reserve_map(struct device *dev, struct pinctrl_map **map,
+                       unsigned *reserved_maps, unsigned *num_maps,
+                       unsigned reserve)
 {
         unsigned old_num = *reserved_maps;
         unsigned new_num = *num_maps + reserve;
@@ -103,8 +104,10 @@ static int reserve_map(struct pinctrl_map **map, unsigned *reserved_maps,
                 return 0;
 
         new_map = krealloc(*map, sizeof(*new_map) * new_num, GFP_KERNEL);
-        if (!new_map)
+        if (!new_map) {
+                dev_err(dev, "krealloc(map) failed\n");
                 return -ENOMEM;
+        }
 
         memset(new_map + old_num, 0, (new_num - old_num) * sizeof(*new_map));
 
@@ -118,7 +121,7 @@ static int add_map_mux(struct pinctrl_map **map, unsigned *reserved_maps,
                        unsigned *num_maps, const char *group,
                        const char *function)
 {
-        if (*num_maps == *reserved_maps)
+        if (WARN_ON(*num_maps == *reserved_maps))
                 return -ENOSPC;
 
         (*map)[*num_maps].type = PIN_MAP_TYPE_MUX_GROUP;
@@ -129,19 +132,22 @@ static int add_map_mux(struct pinctrl_map **map, unsigned *reserved_maps,
         return 0;
 }
 
-static int add_map_configs(struct pinctrl_map **map, unsigned *reserved_maps,
-                           unsigned *num_maps, const char *group,
-                           unsigned long *configs, unsigned num_configs)
+static int add_map_configs(struct device *dev, struct pinctrl_map **map,
+                           unsigned *reserved_maps, unsigned *num_maps,
+                           const char *group, unsigned long *configs,
+                           unsigned num_configs)
 {
         unsigned long *dup_configs;
 
-        if (*num_maps == *reserved_maps)
+        if (WARN_ON(*num_maps == *reserved_maps))
                 return -ENOSPC;
 
         dup_configs = kmemdup(configs, num_configs * sizeof(*dup_configs),
                               GFP_KERNEL);
-        if (!dup_configs)
+        if (!dup_configs) {
+                dev_err(dev, "kmemdup(configs) failed\n");
                 return -ENOMEM;
+        }
 
         (*map)[*num_maps].type = PIN_MAP_TYPE_CONFIGS_GROUP;
         (*map)[*num_maps].data.configs.group_or_pin = group;
@@ -152,8 +158,8 @@ static int add_map_configs(struct pinctrl_map **map, unsigned *reserved_maps,
         return 0;
 }
 
-static int add_config(unsigned long **configs, unsigned *num_configs,
-                      unsigned long config)
+static int add_config(struct device *dev, unsigned long **configs,
+                      unsigned *num_configs, unsigned long config)
 {
         unsigned old_num = *num_configs;
         unsigned new_num = old_num + 1;
@@ -161,8 +167,10 @@ static int add_config(unsigned long **configs, unsigned *num_configs,
 
         new_configs = krealloc(*configs, sizeof(*new_configs) * new_num,
                                GFP_KERNEL);
-        if (!new_configs)
+        if (!new_configs) {
+                dev_err(dev, "krealloc(configs) failed\n");
                 return -ENOMEM;
+        }
 
         new_configs[old_num] = config;
 
@@ -203,7 +211,8 @@ static const struct cfg_param {
         {"nvidia,slew-rate-rising",     TEGRA_PINCONF_PARAM_SLEW_RATE_RISING},
 };
 
-int tegra_pinctrl_dt_subnode_to_map(struct device_node *np,
+int tegra_pinctrl_dt_subnode_to_map(struct device *dev,
+                                    struct device_node *np,
                                     struct pinctrl_map **map,
                                     unsigned *reserved_maps,
                                     unsigned *num_maps)
@@ -219,16 +228,25 @@ int tegra_pinctrl_dt_subnode_to_map(struct device_node *np,
         const char *group;
 
         ret = of_property_read_string(np, "nvidia,function", &function);
-        if (ret < 0)
+        if (ret < 0) {
+                /* EINVAL=missing, which is fine since it's optional */
+                if (ret != -EINVAL)
+                        dev_err(dev,
+                                "could not parse property nvidia,function\n");
                 function = NULL;
+        }
 
         for (i = 0; i < ARRAY_SIZE(cfg_params); i++) {
                 ret = of_property_read_u32(np, cfg_params[i].property, &val);
                 if (!ret) {
                         config = TEGRA_PINCONF_PACK(cfg_params[i].param, val);
-                        ret = add_config(&configs, &num_configs, config);
+                        ret = add_config(dev, &configs, &num_configs, config);
                         if (ret < 0)
                                 goto exit;
+                /* EINVAL=missing, which is fine since it's optional */
+                } else if (ret != -EINVAL) {
+                        dev_err(dev, "could not parse property %s\n",
+                                cfg_params[i].property);
                 }
         }
 
@@ -238,11 +256,13 @@ int tegra_pinctrl_dt_subnode_to_map(struct device_node *np,
         if (num_configs)
                 reserve++;
         ret = of_property_count_strings(np, "nvidia,pins");
-        if (ret < 0)
+        if (ret < 0) {
+                dev_err(dev, "could not parse property nvidia,pins\n");
                 goto exit;
+        }
         reserve *= ret;
 
-        ret = reserve_map(map, reserved_maps, num_maps, reserve);
+        ret = reserve_map(dev, map, reserved_maps, num_maps, reserve);
         if (ret < 0)
                 goto exit;
 
@@ -255,8 +275,9 @@ int tegra_pinctrl_dt_subnode_to_map(struct device_node *np,
                 }
 
                 if (num_configs) {
-                        ret = add_map_configs(map, reserved_maps, num_maps,
-                                              group, configs, num_configs);
+                        ret = add_map_configs(dev, map, reserved_maps,
+                                              num_maps, group, configs,
+                                              num_configs);
                         if (ret < 0)
                                 goto exit;
                 }
@@ -282,8 +303,8 @@ int tegra_pinctrl_dt_node_to_map(struct pinctrl_dev *pctldev,
         *num_maps = 0;
 
         for_each_child_of_node(np_config, np) {
-                ret = tegra_pinctrl_dt_subnode_to_map(np, map, &reserved_maps,
-                                                      num_maps);
+                ret = tegra_pinctrl_dt_subnode_to_map(pctldev->dev, np, map,
+                                                      &reserved_maps, num_maps);
                 if (ret < 0) {
                         tegra_pinctrl_dt_free_map(pctldev, *map, *num_maps);
                         return ret;
@@ -342,14 +363,14 @@ static int tegra_pinctrl_enable(struct pinctrl_dev *pctldev, unsigned function,
 
         g = &pmx->soc->groups[group];
 
-        if (g->mux_reg < 0)
+        if (WARN_ON(g->mux_reg < 0))
                 return -EINVAL;
 
         for (i = 0; i < ARRAY_SIZE(g->funcs); i++) {
                 if (g->funcs[i] == function)
                         break;
         }
-        if (i == ARRAY_SIZE(g->funcs))
+        if (WARN_ON(i == ARRAY_SIZE(g->funcs)))
                 return -EINVAL;
 
         val = pmx_readl(pmx, g->mux_bank, g->mux_reg);
@@ -369,7 +390,7 @@ static void tegra_pinctrl_disable(struct pinctrl_dev *pctldev,
 
         g = &pmx->soc->groups[group];
 
-        if (g->mux_reg < 0)
+        if (WARN_ON(g->mux_reg < 0))
                 return;
 
         val = pmx_readl(pmx, g->mux_bank, g->mux_reg);
@@ -490,12 +511,14 @@ static int tegra_pinconf_reg(struct tegra_pmx *pmx,
 static int tegra_pinconf_get(struct pinctrl_dev *pctldev,
                              unsigned pin, unsigned long *config)
 {
+        dev_err(pctldev->dev, "pin_config_get op not supported\n");
         return -ENOTSUPP;
 }
 
 static int tegra_pinconf_set(struct pinctrl_dev *pctldev,
                              unsigned pin, unsigned long config)
 {
+        dev_err(pctldev->dev, "pin_config_set op not supported\n");
         return -ENOTSUPP;
 }
 
@@ -550,8 +573,10 @@ static int tegra_pinconf_group_set(struct pinctrl_dev *pctldev,
 
         /* LOCK can't be cleared */
         if (param == TEGRA_PINCONF_PARAM_LOCK) {
-                if ((val & BIT(bit)) && !arg)
+                if ((val & BIT(bit)) && !arg) {
+                        dev_err(pctldev->dev, "LOCK bit cannot be cleared\n");
                         return -EINVAL;
+                }
         }
 
         /* Special-case Boolean values; allow any non-zero as true */
@@ -560,8 +585,12 @@ static int tegra_pinconf_group_set(struct pinctrl_dev *pctldev,
 
         /* Range-check user-supplied value */
         mask = (1 << width) - 1;
-        if (arg & ~mask)
+        if (arg & ~mask) {
+                dev_err(pctldev->dev,
+                        "config %lx: %x too big for %d bit register\n",
+                        config, arg, width);
                 return -EINVAL;
+        }
 
         /* Update register */
         val &= ~(mask << bit);