of/gpio: add default of_xlate function if device has a node pointer

Implement generic OF gpio hooks and thus make device-enabled GPIO chips
(i.e.  the ones that have gpio_chip->dev specified) automatically attach
to the OpenFirmware subsystem.  Which means that now we can handle I2C and
SPI GPIO chips almost* transparently.

* "Almost" because some chips still require platform data, and for these
  chips OF-glue is still needed, though with this change the glue will
  be much smaller.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Bill Gatliff <bgat@billgatliff.com>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
CC: linux-kernel@vger.kernel.org
CC: devicetree-discuss@lists.ozlabs.org

13 files changed, 34 insertions, 26 deletions

diff --git a/arch/powerpc/platforms/52xx/mpc52xx_gpio.c b/arch/powerpc/platforms/52xx/mpc52xx_gpio.c
index fd0912eeffe2..0855e804fc0d 100644
--- a/arch/powerpc/platforms/52xx/mpc52xx_gpio.c
+++ b/arch/powerpc/platforms/52xx/mpc52xx_gpio.c
@@ -161,7 +161,6 @@ static int __devinit mpc52xx_wkup_gpiochip_probe(struct of_device *ofdev,
 
         gc = &chip->mmchip.gc;
 
-        gc->of_gpio_n_cells  = 2;
         gc->ngpio            = 8;
         gc->direction_input  = mpc52xx_wkup_gpio_dir_in;
         gc->direction_output = mpc52xx_wkup_gpio_dir_out;
@@ -325,7 +324,6 @@ static int __devinit mpc52xx_simple_gpiochip_probe(struct of_device *ofdev,
 
         gc = &chip->mmchip.gc;
 
-        gc->of_gpio_n_cells  = 2;
         gc->ngpio            = 32;
         gc->direction_input  = mpc52xx_simple_gpio_dir_in;
         gc->direction_output = mpc52xx_simple_gpio_dir_out;
diff --git a/arch/powerpc/platforms/52xx/mpc52xx_gpt.c b/arch/powerpc/platforms/52xx/mpc52xx_gpt.c
index 6e82bd27132c..5d7d607617cd 100644
--- a/arch/powerpc/platforms/52xx/mpc52xx_gpt.c
+++ b/arch/powerpc/platforms/52xx/mpc52xx_gpt.c
@@ -348,10 +348,7 @@ mpc52xx_gpt_gpio_setup(struct mpc52xx_gpt_priv *gpt, struct device_node *node)
         gpt->gc.get = mpc52xx_gpt_gpio_get;
         gpt->gc.set = mpc52xx_gpt_gpio_set;
         gpt->gc.base = -1;
-        gpt->gc.of_gpio_n_cells = 2;
-        gpt->gc.of_xlate = of_gpio_simple_xlate;
         gpt->gc.of_node = node;
-        of_node_get(node);
 
         /* Setup external pin in GPIO mode */
         clrsetbits_be32(&gpt->regs->mode, MPC52xx_GPT_MODE_MS_MASK,
diff --git a/arch/powerpc/platforms/83xx/mcu_mpc8349emitx.c b/arch/powerpc/platforms/83xx/mcu_mpc8349emitx.c
index f0dbace6185a..59b0ed1a56b1 100644
--- a/arch/powerpc/platforms/83xx/mcu_mpc8349emitx.c
+++ b/arch/powerpc/platforms/83xx/mcu_mpc8349emitx.c
@@ -90,8 +90,6 @@ static int mcu_gpiochip_add(struct mcu *mcu)
         gc->base = -1;
         gc->set = mcu_gpio_set;
         gc->direction_output = mcu_gpio_dir_out;
-        gc->of_gpio_n_cells = 2;
-        gc->of_xlate = of_gpio_simple_xlate;
         gc->of_node = np;
 
         return gpiochip_add(gc);
diff --git a/arch/powerpc/sysdev/cpm1.c b/arch/powerpc/sysdev/cpm1.c
index d5cf7d4ccf81..00852124ff4a 100644
--- a/arch/powerpc/sysdev/cpm1.c
+++ b/arch/powerpc/sysdev/cpm1.c
@@ -633,7 +633,6 @@ int cpm1_gpiochip_add16(struct device_node *np)
         gc = &mm_gc->gc;
 
         mm_gc->save_regs = cpm1_gpio16_save_regs;
-        gc->of_gpio_n_cells = 2;
         gc->ngpio = 16;
         gc->direction_input = cpm1_gpio16_dir_in;
         gc->direction_output = cpm1_gpio16_dir_out;
@@ -755,7 +754,6 @@ int cpm1_gpiochip_add32(struct device_node *np)
         gc = &mm_gc->gc;
 
         mm_gc->save_regs = cpm1_gpio32_save_regs;
-        gc->of_gpio_n_cells = 2;
         gc->ngpio = 32;
         gc->direction_input = cpm1_gpio32_dir_in;
         gc->direction_output = cpm1_gpio32_dir_out;
diff --git a/arch/powerpc/sysdev/cpm_common.c b/arch/powerpc/sysdev/cpm_common.c
index 67e9b47dcf8e..2b69aa0315b3 100644
--- a/arch/powerpc/sysdev/cpm_common.c
+++ b/arch/powerpc/sysdev/cpm_common.c
@@ -337,7 +337,6 @@ int cpm2_gpiochip_add32(struct device_node *np)
         gc = &mm_gc->gc;
 
         mm_gc->save_regs = cpm2_gpio32_save_regs;
-        gc->of_gpio_n_cells = 2;
         gc->ngpio = 32;
         gc->direction_input = cpm2_gpio32_dir_in;
         gc->direction_output = cpm2_gpio32_dir_out;
diff --git a/arch/powerpc/sysdev/mpc8xxx_gpio.c b/arch/powerpc/sysdev/mpc8xxx_gpio.c
index ec8fcd42101e..2b69084d0f0c 100644
--- a/arch/powerpc/sysdev/mpc8xxx_gpio.c
+++ b/arch/powerpc/sysdev/mpc8xxx_gpio.c
@@ -273,7 +273,6 @@ static void __init mpc8xxx_add_controller(struct device_node *np)
         gc = &mm_gc->gc;
 
         mm_gc->save_regs = mpc8xxx_gpio_save_regs;
-        gc->of_gpio_n_cells = 2;
         gc->ngpio = MPC8XXX_GPIO_PINS;
         gc->direction_input = mpc8xxx_gpio_dir_in;
         gc->direction_output = mpc8xxx_gpio_dir_out;
diff --git a/arch/powerpc/sysdev/ppc4xx_gpio.c b/arch/powerpc/sysdev/ppc4xx_gpio.c
index 42e7a5eea665..fc65ad1b3293 100644
--- a/arch/powerpc/sysdev/ppc4xx_gpio.c
+++ b/arch/powerpc/sysdev/ppc4xx_gpio.c
@@ -194,7 +194,6 @@ static int __init ppc4xx_add_gpiochips(void)
                 mm_gc = &ppc4xx_gc->mm_gc;
                 gc = &mm_gc->gc;
 
-                gc->of_gpio_n_cells = 2;
                 gc->ngpio = 32;
                 gc->direction_input = ppc4xx_gpio_dir_in;
                 gc->direction_output = ppc4xx_gpio_dir_out;
diff --git a/arch/powerpc/sysdev/qe_lib/gpio.c b/arch/powerpc/sysdev/qe_lib/gpio.c
index 32e9440010a1..36bf845df127 100644
--- a/arch/powerpc/sysdev/qe_lib/gpio.c
+++ b/arch/powerpc/sysdev/qe_lib/gpio.c
@@ -321,7 +321,6 @@ static int __init qe_add_gpiochips(void)
                 gc = &mm_gc->gc;
 
                 mm_gc->save_regs = qe_gpio_save_regs;
-                gc->of_gpio_n_cells = 2;
                 gc->ngpio = QE_PIO_PINS;
                 gc->direction_input = qe_gpio_dir_in;
                 gc->direction_output = qe_gpio_dir_out;
diff --git a/arch/powerpc/sysdev/simple_gpio.c b/arch/powerpc/sysdev/simple_gpio.c
index b7559aa0c165..b6defda5ccc9 100644
--- a/arch/powerpc/sysdev/simple_gpio.c
+++ b/arch/powerpc/sysdev/simple_gpio.c
@@ -103,7 +103,6 @@ static int __init u8_simple_gpiochip_add(struct device_node *np)
         gc = &mm_gc->gc;
 
         mm_gc->save_regs = u8_gpio_save_regs;
-        gc->of_gpio_n_cells = 2;
         gc->ngpio = 8;
         gc->direction_input = u8_gpio_dir_in;
         gc->direction_output = u8_gpio_dir_out;
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 73fd328f6fe4..83cbc34e3a76 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -8,6 +8,7 @@
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>
 #include <linux/gpio.h>
+#include <linux/of_gpio.h>
 #include <linux/idr.h>
 #include <linux/slab.h>
 
@@ -1099,6 +1100,8 @@ int gpiochip_add(struct gpio_chip *chip)
                 }
         }
 
+        of_gpiochip_add(chip);
+
 unlock:
         spin_unlock_irqrestore(&gpio_lock, flags);
 
@@ -1133,6 +1136,8 @@ int gpiochip_remove(struct gpio_chip *chip)
 
         spin_lock_irqsave(&gpio_lock, flags);
 
+        of_gpiochip_remove(chip);
+
         for (id = chip->base; id < chip->base + chip->ngpio; id++) {
                 if (test_bit(FLAG_REQUESTED, &gpio_desc[id].flags)) {
                         status = -EBUSY;
diff --git a/drivers/gpio/xilinx_gpio.c b/drivers/gpio/xilinx_gpio.c
index 2993c40b48e1..709690995d0d 100644
--- a/drivers/gpio/xilinx_gpio.c
+++ b/drivers/gpio/xilinx_gpio.c
@@ -190,7 +190,6 @@ static int __devinit xgpio_of_probe(struct device_node *np)
 
         spin_lock_init(&chip->gpio_lock);
 
-        chip->mmchip.gc.of_gpio_n_cells = 2;
         chip->mmchip.gc.direction_input = xgpio_dir_in;
         chip->mmchip.gc.direction_output = xgpio_dir_out;
         chip->mmchip.gc.get = xgpio_get;
diff --git a/drivers/of/gpio.c b/drivers/of/gpio.c
index c8618d3282cf..09f05a178668 100644
--- a/drivers/of/gpio.c
+++ b/drivers/of/gpio.c
@@ -125,8 +125,8 @@ EXPORT_SYMBOL(of_gpio_count);
  * gpio chips. This function performs only one sanity check: whether gpio
  * is less than ngpios (that is specified in the gpio_chip).
  */
-int of_gpio_simple_xlate(struct gpio_chip *gc, struct device_node *np,
-                         const void *gpio_spec, u32 *flags)
+static int of_gpio_simple_xlate(struct gpio_chip *gc, struct device_node *np,
+                                const void *gpio_spec, u32 *flags)
 {
         const __be32 *gpio = gpio_spec;
         const u32 n = be32_to_cpup(gpio);
@@ -150,7 +150,6 @@ int of_gpio_simple_xlate(struct gpio_chip *gc, struct device_node *np,
 
         return n;
 }
-EXPORT_SYMBOL(of_gpio_simple_xlate);
 
 /**
  * of_mm_gpiochip_add - Add memory mapped GPIO chip (bank)
@@ -187,9 +186,6 @@ int of_mm_gpiochip_add(struct device_node *np,
 
         gc->base = -1;
 
-        if (!gc->of_xlate)
-                gc->of_xlate = of_gpio_simple_xlate;
-
         if (mm_gc->save_regs)
                 mm_gc->save_regs(mm_gc);
 
@@ -199,9 +195,6 @@ int of_mm_gpiochip_add(struct device_node *np,
         if (ret)
                 goto err2;
 
-        /* We don't want to lose the node and its ->data */
-        of_node_get(np);
-
         pr_debug("%s: registered as generic GPIO chip, base is %d\n",
                  np->full_name, gc->base);
         return 0;
@@ -216,6 +209,28 @@ err0:
 }
 EXPORT_SYMBOL(of_mm_gpiochip_add);
 
+void of_gpiochip_add(struct gpio_chip *chip)
+{
+        if ((!chip->of_node) && (chip->dev))
+                chip->of_node = chip->dev->of_node;
+
+        if (!chip->of_node)
+                return;
+
+        if (!chip->of_xlate) {
+                chip->of_gpio_n_cells = 2;
+                chip->of_xlate = of_gpio_simple_xlate;
+        }
+
+        of_node_get(chip->of_node);
+}
+
+void of_gpiochip_remove(struct gpio_chip *chip)
+{
+        if (chip->of_node)
+                of_node_put(chip->of_node);
+}
+
 /* Private function for resolving node pointer to gpio_chip */
 static int of_gpiochip_is_match(struct gpio_chip *chip, void *data)
 {
diff --git a/include/linux/of_gpio.h b/include/linux/of_gpio.h
index 1020587efed1..6598c04dab01 100644
--- a/include/linux/of_gpio.h
+++ b/include/linux/of_gpio.h
@@ -52,9 +52,9 @@ extern unsigned int of_gpio_count(struct device_node *np);
 
 extern int of_mm_gpiochip_add(struct device_node *np,
                               struct of_mm_gpio_chip *mm_gc);
-extern int of_gpio_simple_xlate(struct gpio_chip *gc, struct device_node *np,
-                                const void *gpio_spec, u32 *flags);
 
+extern void of_gpiochip_add(struct gpio_chip *gc);
+extern void of_gpiochip_remove(struct gpio_chip *gc);
 extern struct gpio_chip *of_node_to_gpiochip(struct device_node *np);
 
 #else /* CONFIG_OF_GPIO */
@@ -71,6 +71,9 @@ static inline unsigned int of_gpio_count(struct device_node *np)
         return 0;
 }
 
+static inline void of_gpiochip_add(struct gpio_chip *gc) { }
+static inline void of_gpiochip_remove(struct gpio_chip *gc) { }
+
 #endif /* CONFIG_OF_GPIO */
 
 /**