of/gpio: Kill of_gpio_chip and add members directly to gpio_chip

The OF gpio infrastructure is great for describing GPIO connections within
the device tree.  However, using a GPIO binding still requires changes to
the gpio controller just to add an of_gpio structure.  In most cases, the
gpio controller doesn't actually need any special support and the simple
OF gpio mapping function is more than sufficient.  Additional, the current
scheme of using of_gpio_chip requires a convoluted scheme to maintain
1:1 mappings between of_gpio_chip and gpio_chip instances.

If the struct of_gpio_chip data members were moved into struct gpio_chip,
then it would simplify the processing of OF gpio bindings, and it would
make it trivial to use device tree OF connections on existing gpiolib
controller drivers.

This patch eliminates the of_gpio_chip structure and moves the relevant
fields into struct gpio_chip (conditional on CONFIG_OF_GPIO).  This move
simplifies the existing code and prepares for adding automatic device tree
support to existing drivers.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Anton Vorontsov <avorontsov@ru.mvista.com>
Cc: 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>

1 files changed, 15 insertions, 17 deletions

diff --git a/arch/powerpc/sysdev/qe_lib/gpio.c b/arch/powerpc/sysdev/qe_lib/gpio.c
index dc8f8d618074..194478c2f4b4 100644
--- a/arch/powerpc/sysdev/qe_lib/gpio.c
+++ b/arch/powerpc/sysdev/qe_lib/gpio.c
@@ -138,8 +138,8 @@ struct qe_pin {
 struct qe_pin *qe_pin_request(struct device_node *np, int index)
 {
         struct qe_pin *qe_pin;
-        struct device_node *gc;
-        struct of_gpio_chip *of_gc = NULL;
+        struct device_node *gpio_np;
+        struct gpio_chip *gc;
         struct of_mm_gpio_chip *mm_gc;
         struct qe_gpio_chip *qe_gc;
         int err;
@@ -155,40 +155,40 @@ struct qe_pin *qe_pin_request(struct device_node *np, int index)
         }
 
         err = of_parse_phandles_with_args(np, "gpios", "#gpio-cells", index,
-                                          &gc, &gpio_spec);
+                                          &gpio_np, &gpio_spec);
         if (err) {
                 pr_debug("%s: can't parse gpios property\n", __func__);
                 goto err0;
         }
 
-        if (!of_device_is_compatible(gc, "fsl,mpc8323-qe-pario-bank")) {
+        if (!of_device_is_compatible(gpio_np, "fsl,mpc8323-qe-pario-bank")) {
                 pr_debug("%s: tried to get a non-qe pin\n", __func__);
                 err = -EINVAL;
                 goto err1;
         }
 
-        of_gc = gc->data;
-        if (!of_gc) {
+        gc = gpio_np->data;
+        if (!gc) {
                 pr_debug("%s: gpio controller %s isn't registered\n",
-                         np->full_name, gc->full_name);
+                         np->full_name, gpio_np->full_name);
                 err = -ENODEV;
                 goto err1;
         }
 
-        gpio_cells = of_get_property(gc, "#gpio-cells", &size);
+        gpio_cells = of_get_property(gpio_np, "#gpio-cells", &size);
         if (!gpio_cells || size != sizeof(*gpio_cells) ||
-                        *gpio_cells != of_gc->gpio_cells) {
+                        *gpio_cells != gc->of_gpio_n_cells) {
                 pr_debug("%s: wrong #gpio-cells for %s\n",
-                         np->full_name, gc->full_name);
+                         np->full_name, gpio_np->full_name);
                 err = -EINVAL;
                 goto err1;
         }
 
-        err = of_gc->xlate(of_gc, np, gpio_spec, NULL);
+        err = gc->of_xlate(gc, np, gpio_spec, NULL);
         if (err < 0)
                 goto err1;
 
-        mm_gc = to_of_mm_gpio_chip(&of_gc->gc);
+        mm_gc = to_of_mm_gpio_chip(gc);
         qe_gc = to_qe_gpio_chip(mm_gc);
 
         spin_lock_irqsave(&qe_gc->lock, flags);
@@ -206,7 +206,7 @@ struct qe_pin *qe_pin_request(struct device_node *np, int index)
         if (!err)
                 return qe_pin;
 err1:
-        of_node_put(gc);
+        of_node_put(gpio_np);
 err0:
         kfree(qe_pin);
         pr_debug("%s failed with status %d\n", __func__, err);
@@ -307,7 +307,6 @@ static int __init qe_add_gpiochips(void)
                 int ret;
                 struct qe_gpio_chip *qe_gc;
                 struct of_mm_gpio_chip *mm_gc;
-                struct of_gpio_chip *of_gc;
                 struct gpio_chip *gc;
 
                 qe_gc = kzalloc(sizeof(*qe_gc), GFP_KERNEL);
@@ -319,11 +318,10 @@ static int __init qe_add_gpiochips(void)
                 spin_lock_init(&qe_gc->lock);
 
                 mm_gc = &qe_gc->mm_gc;
-                of_gc = &mm_gc->of_gc;
-                gc = &of_gc->gc;
+                gc = &mm_gc->gc;
 
                 mm_gc->save_regs = qe_gpio_save_regs;
-                of_gc->gpio_cells = 2;
+                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;