pinctrl / gpio: Introduce .set_config() callback for GPIO chips

Currently we already have two pin configuration related callbacks
available for GPIO chips .set_single_ended() and .set_debounce(). In
future we expect to have even more, which does not scale well if we need
to add yet another callback to the GPIO chip structure for each possible
configuration parameter.

Better solution is to reuse what we already have available in the
generic pinconf.

To support this, we introduce a new .set_config() callback for GPIO
chips. The callback takes a single packed pin configuration value as
parameter. This can then be extended easily beyond what is currently
supported by just adding new types to the generic pinconf enum.

If the GPIO driver is backed up by a pinctrl driver the GPIO driver can
just assign gpiochip_generic_config() (introduced in this patch) to
.set_config and that will take care configuration requests are directed
to the pinctrl driver.

We then convert the existing drivers over .set_config() and finally
remove the .set_single_ended() and .set_debounce() callbacks.

Suggested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 8 insertions, 29 deletions

diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index c2748accea71..db2022910caf 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -8,6 +8,7 @@
 #include <linux/irqdomain.h>
 #include <linux/lockdep.h>
 #include <linux/pinctrl/pinctrl.h>
+#include <linux/pinctrl/pinconf-generic.h>
 
 struct gpio_desc;
 struct of_phandle_args;
@@ -19,18 +20,6 @@ struct module;
 #ifdef CONFIG_GPIOLIB
 
 /**
- * enum single_ended_mode - mode for single ended operation
- * @LINE_MODE_PUSH_PULL: normal mode for a GPIO line, drive actively high/low
- * @LINE_MODE_OPEN_DRAIN: set line to be open drain
- * @LINE_MODE_OPEN_SOURCE: set line to be open source
- */
-enum single_ended_mode {
-        LINE_MODE_PUSH_PULL,
-        LINE_MODE_OPEN_DRAIN,
-        LINE_MODE_OPEN_SOURCE,
-};
-
-/**
  * struct gpio_chip - abstract a GPIO controller
  * @label: a functional name for the GPIO device, such as a part
  *      number or the name of the SoC IP-block implementing it.
@@ -48,16 +37,8 @@ enum single_ended_mode {
  * @get: returns value for signal "offset", 0=low, 1=high, or negative error
  * @set: assigns output value for signal "offset"
  * @set_multiple: assigns output values for multiple signals defined by "mask"
- * @set_debounce: optional hook for setting debounce time for specified gpio in
- *      interrupt triggered gpio chips
- * @set_single_ended: optional hook for setting a line as open drain, open
- *      source, or non-single ended (restore from open drain/source to normal
- *      push-pull mode) this should be implemented if the hardware supports
- *      open drain or open source settings. The GPIOlib will otherwise try
- *      to emulate open drain/source by not actively driving lines high/low
- *      if a consumer request this. The driver may return -ENOTSUPP if e.g.
- *      it supports just open drain but not open source and is called
- *      with LINE_MODE_OPEN_SOURCE as mode argument.
+ * @set_config: optional hook for all kinds of settings. Uses the same
+ *      packed config format as generic pinconf.
  * @to_irq: optional hook supporting non-static gpio_to_irq() mappings;
  *      implementation may not sleep
  * @dbg_show: optional routine to show contents in debugfs; default code
@@ -150,13 +131,9 @@ struct gpio_chip {
         void                    (*set_multiple)(struct gpio_chip *chip,
                                                 unsigned long *mask,
                                                 unsigned long *bits);
-        int                     (*set_debounce)(struct gpio_chip *chip,
-                                                unsigned offset,
-                                                unsigned debounce);
-        int                     (*set_single_ended)(struct gpio_chip *chip,
-                                                unsigned offset,
-                                                enum single_ended_mode mode);
-
+        int                     (*set_config)(struct gpio_chip *chip,
+                                              unsigned offset,
+                                              unsigned long config);
         int                     (*to_irq)(struct gpio_chip *chip,
                                                 unsigned offset);
 
@@ -310,6 +287,8 @@ static inline int gpiochip_irqchip_add_nested(struct gpio_chip *gpiochip,
 
 int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset);
 void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset);
+int gpiochip_generic_config(struct gpio_chip *chip, unsigned offset,
+                            unsigned long config);
 
 #ifdef CONFIG_PINCTRL