pinctrl: implement pinctrl_check_ops

Most code assumes that the pinctrl ops are present. Validate this when
registering a pinctrl driver. Remove the one place in the code that
was checking whether one of these non-optional ops was present.

Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 21 insertions, 4 deletions

diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index ec3b8cc188af..df6296c5f47b 100644
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -908,10 +908,6 @@ static int pinctrl_groups_show(struct seq_file *s, void *what)
         const struct pinctrl_ops *ops = pctldev->desc->pctlops;
         unsigned selector = 0;
 
-        /* No grouping */
-        if (!ops)
-                return 0;
-
         mutex_lock(&pinctrl_mutex);
 
         seq_puts(s, "registered pin groups:\n");
@@ -1225,6 +1221,19 @@ static void pinctrl_remove_device_debugfs(struct pinctrl_dev *pctldev)
 
 #endif
 
+static int pinctrl_check_ops(struct pinctrl_dev *pctldev)
+{
+        const struct pinctrl_ops *ops = pctldev->desc->pctlops;
+
+        if (!ops ||
+            !ops->list_groups ||
+            !ops->get_group_name ||
+            !ops->get_group_pins)
+                return -EINVAL;
+
+        return 0;
+}
+
 /**
  * pinctrl_register() - register a pin controller device
  * @pctldesc: descriptor for this pin controller
@@ -1256,6 +1265,14 @@ struct pinctrl_dev *pinctrl_register(struct pinctrl_desc *pctldesc,
         INIT_LIST_HEAD(&pctldev->gpio_ranges);
         pctldev->dev = dev;
 
+        /* check core ops for sanity */
+        ret = pinctrl_check_ops(pctldev);
+        if (ret) {
+                pr_err("%s pinctrl ops lacks necessary functions\n",
+                        pctldesc->name);
+                goto out_err;
+        }
+
         /* If we're implementing pinmuxing, check the ops for sanity */
         if (pctldesc->pmxops) {
                 ret = pinmux_check_ops(pctldev);