gpio: mpc8xxx: don't allow input-only pins to be output for MPC5121

Add a 5121-custom reject if an input-only pin is requested to be output
(see 18.3.1.1 in the refman). Also, rewrite mach-specific quirk setup to
consume less lines which scales better.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
[grant.likely: Fixed build error]
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 13 insertions, 5 deletions

diff --git a/drivers/gpio/gpio-mpc8xxx.c b/drivers/gpio/gpio-mpc8xxx.c
index ec3fcf0a7e12..5cd04b65c556 100644
--- a/drivers/gpio/gpio-mpc8xxx.c
+++ b/drivers/gpio/gpio-mpc8xxx.c
@@ -132,6 +132,15 @@ static int mpc8xxx_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val
         return 0;
 }
 
+static int mpc5121_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
+{
+        /* GPIO 28..31 are input only on MPC5121 */
+        if (gpio >= 28)
+                return -EINVAL;
+
+        return mpc8xxx_gpio_dir_out(gc, gpio, val);
+}
+
 static int mpc8xxx_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
 {
         struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);
@@ -340,11 +349,10 @@ static void __init mpc8xxx_add_controller(struct device_node *np)
         mm_gc->save_regs = mpc8xxx_gpio_save_regs;
         gc->ngpio = MPC8XXX_GPIO_PINS;
         gc->direction_input = mpc8xxx_gpio_dir_in;
-        gc->direction_output = mpc8xxx_gpio_dir_out;
-        if (of_device_is_compatible(np, "fsl,mpc8572-gpio"))
-                gc->get = mpc8572_gpio_get;
-        else
-                gc->get = mpc8xxx_gpio_get;
+        gc->direction_output = of_device_is_compatible(np, "fsl,mpc5121-gpio") ?
+                mpc5121_gpio_dir_out : mpc8xxx_gpio_dir_out;
+        gc->get = of_device_is_compatible(np, "fsl,mpc8572-gpio") ?
+                mpc8572_gpio_get : mpc8xxx_gpio_get;
         gc->set = mpc8xxx_gpio_set;
         gc->to_irq = mpc8xxx_gpio_to_irq;