pinctrl: samsung: Use one GPIO chip per pin bank

This patch modifies the pinctrl-samsung driver to register one GPIO chip
per pin bank, instead of a single chip for all pin banks of the
controller.

It simplifies GPIO accesses a lot (constant time instead of looping
through the list of banks to find the right one) and should have a good
effect on performance of any bit-banging driver.

In addition it allows to reference GPIO pins by a phandle to the bank
node and a local pin offset inside of the bank (similar to previous
gpiolib driver), which is more clear and readable than using indices
relative to the whole pin controller.

Example:
	device {
		/* ... */
		gpios = <&gpk0 4 0>;
		/* ... */
	};

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
Reviewed-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Thomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 6 insertions, 5 deletions

diff --git a/drivers/pinctrl/pinctrl-samsung.h b/drivers/pinctrl/pinctrl-samsung.h
index e56be22302cd..dac40ffd5e67 100644
--- a/drivers/pinctrl/pinctrl-samsung.h
+++ b/drivers/pinctrl/pinctrl-samsung.h
@@ -23,6 +23,8 @@
 #include <linux/pinctrl/consumer.h>
 #include <linux/pinctrl/machine.h>
 
+#include <linux/gpio.h>
+
 /* register offsets within a pin bank */
 #define DAT_REG         0x4
 #define PUD_REG         0x8
@@ -113,6 +115,8 @@ struct samsung_pinctrl_drv_data;
  * @of_node: OF node of the bank.
  * @drvdata: link to controller driver data
  * @irq_domain: IRQ domain of the bank.
+ * @gpio_chip: GPIO chip of the bank.
+ * @grange: linux gpio pin range supported by this bank.
  */
 struct samsung_pin_bank {
         u32             pctl_offset;
@@ -129,6 +133,8 @@ struct samsung_pin_bank {
         struct device_node *of_node;
         struct samsung_pinctrl_drv_data *drvdata;
         struct irq_domain *irq_domain;
+        struct gpio_chip gpio_chip;
+        struct pinctrl_gpio_range grange;
 };
 
 /**
@@ -186,8 +192,6 @@ struct samsung_pin_ctrl {
  * @nr_groups: number of such pin groups.
  * @pmx_functions: list of pin functions available to the driver.
  * @nr_function: number of such pin functions.
- * @gc: gpio_chip instance registered with gpiolib.
- * @grange: linux gpio pin range supported by this controller.
  */
 struct samsung_pinctrl_drv_data {
         void __iomem                    *virt_base;
@@ -204,9 +208,6 @@ struct samsung_pinctrl_drv_data {
         unsigned int                    nr_functions;
 
         struct irq_domain               *wkup_irqd;
-
-        struct gpio_chip                *gc;
-        struct pinctrl_gpio_range       grange;
 };
 
 /**