pinctrl: pinconf-generic: Allow driver to specify DT params

Additionally to the generic DT parameters, allow drivers to provide
driver-specific DT parameters to be used with the generic parser
infrastructure.

To achieve this 'struct pinctrl_desc' is extended to pass custom pinconf
option to the core. In order to pass this kind of information, the
related data structures - 'struct pinconf_generic_dt_params',
'pin_config_item' - are moved from pinconf internals to the
pinconf-generic header.

Additionally pinconfg-generic is refactored to not only iterate over the
generic pinconf parameters but also take the parameters into account
that are provided through the driver's 'struct pinctrl_desc'.
In particular 'pinconf_generic_parse_dt_config()' and
'pinconf_generic_dump' helpers are split into two parts each. In order
to have a more generic helper that can be used to process the generic
parameters as well as the driver-specific ones.

v2:
 - fix typo
 - add missing documentation for @conf_items member in struct
 - rebase to pinctrl/devel: conflict in abx500
 - rename _pinconf_generic_dump() to pinconf_generic_dump_one()
 - removed '_' from _parse_dt_cfg()
 - removed BUG_ONs, error condition is handled in if statements
 - removed pinconf_generic_dump_group() & pinconf_generic_dump_pin
   helpers
   - fixed up corresponding call sites
   - renamed pinconf_generic_dump() to pinconf_generic_dump_pins()
   - added kernel-doc to pinconf_generic_dump_pins()
 - add kernel-doc
 - more verbose commit message

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Tested-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

2 files changed, 27 insertions, 0 deletions

diff --git a/include/linux/pinctrl/pinconf-generic.h b/include/linux/pinctrl/pinconf-generic.h
index 83c89f5ab705..342409f7f3ec 100644
--- a/include/linux/pinctrl/pinconf-generic.h
+++ b/include/linux/pinctrl/pinconf-generic.h
@@ -115,6 +115,18 @@ enum pin_config_param {
         PIN_CONFIG_END = 0x7FFF,
 };
 
+#ifdef CONFIG_DEBUG_FS
+#define PCONFDUMP(a, b, c, d) { .param = a, .display = b, .format = c, \
+                                .has_arg = d }
+
+struct pin_config_item {
+        const enum pin_config_param param;
+        const char * const display;
+        const char * const format;
+        bool has_arg;
+};
+#endif /* CONFIG_DEBUG_FS */
+
 /*
  * Helpful configuration macro to be used in tables etc.
  */
@@ -150,6 +162,12 @@ static inline unsigned long pinconf_to_config_packed(enum pin_config_param param
 struct pinctrl_dev;
 struct pinctrl_map;
 
+struct pinconf_generic_dt_params {
+        const char * const property;
+        enum pin_config_param param;
+        u32 default_value;
+};
+
 int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
                 struct device_node *np, struct pinctrl_map **map,
                 unsigned *reserved_maps, unsigned *num_maps,
diff --git a/include/linux/pinctrl/pinctrl.h b/include/linux/pinctrl/pinctrl.h
index cc8e1aff0e28..c58b3e11ba8e 100644
--- a/include/linux/pinctrl/pinctrl.h
+++ b/include/linux/pinctrl/pinctrl.h
@@ -24,6 +24,7 @@ struct pinctrl_dev;
 struct pinctrl_map;
 struct pinmux_ops;
 struct pinconf_ops;
+struct pin_config_item;
 struct gpio_chip;
 struct device_node;
 
@@ -117,6 +118,9 @@ struct pinctrl_ops {
  * @confops: pin config operations vtable, if you support pin configuration in
  *      your driver
  * @owner: module providing the pin controller, used for refcounting
+ * @num_dt_params: Number of driver-specific DT parameters
+ * @params: List of DT parameters
+ * @conf_items: Information how to print @params in debugfs
  */
 struct pinctrl_desc {
         const char *name;
@@ -126,6 +130,11 @@ struct pinctrl_desc {
         const struct pinmux_ops *pmxops;
         const struct pinconf_ops *confops;
         struct module *owner;
+#if defined(CONFIG_GENERIC_PINCONF) && defined(CONFIG_OF)
+        unsigned int num_dt_params;
+        const struct pinconf_generic_dt_params *params;
+        const struct pin_config_item *conf_items;
+#endif
 };
 
 /* External interface to pin controller */