Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / arch / powerpc / sysdev / simple_gpio.c

diff --git a/kernel/arch/powerpc/sysdev/simple_gpio.c b/kernel/arch/powerpc/sysdev/simple_gpio.c
new file mode 100644 (file)
index 0000000..ff5e732
--- /dev/null
+++ b/kernel/arch/powerpc/sysdev/simple_gpio.c
@@ -0,0 +1,152 @@
+/*
+ * Simple Memory-Mapped GPIOs
+ *
+ * Copyright (c) MontaVista Software, Inc. 2008.
+ *
+ * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include <linux/ioport.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/gpio.h>
+#include <linux/slab.h>
+#include <asm/prom.h>
+#include "simple_gpio.h"
+
+struct u8_gpio_chip {
+       struct of_mm_gpio_chip mm_gc;
+       spinlock_t lock;
+
+       /* shadowed data register to clear/set bits safely */
+       u8 data;
+};
+
+static struct u8_gpio_chip *to_u8_gpio_chip(struct of_mm_gpio_chip *mm_gc)
+{
+       return container_of(mm_gc, struct u8_gpio_chip, mm_gc);
+}
+
+static u8 u8_pin2mask(unsigned int pin)
+{
+       return 1 << (8 - 1 - pin);
+}
+
+static int u8_gpio_get(struct gpio_chip *gc, unsigned int gpio)
+{
+       struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
+
+       return in_8(mm_gc->regs) & u8_pin2mask(gpio);
+}
+
+static void u8_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
+{
+       struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
+       struct u8_gpio_chip *u8_gc = to_u8_gpio_chip(mm_gc);
+       unsigned long flags;
+
+       spin_lock_irqsave(&u8_gc->lock, flags);
+
+       if (val)
+               u8_gc->data |= u8_pin2mask(gpio);
+       else
+               u8_gc->data &= ~u8_pin2mask(gpio);
+
+       out_8(mm_gc->regs, u8_gc->data);
+
+       spin_unlock_irqrestore(&u8_gc->lock, flags);
+}
+
+static int u8_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
+{
+       return 0;
+}
+
+static int u8_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
+{
+       u8_gpio_set(gc, gpio, val);
+       return 0;
+}
+
+static void u8_gpio_save_regs(struct of_mm_gpio_chip *mm_gc)
+{
+       struct u8_gpio_chip *u8_gc = to_u8_gpio_chip(mm_gc);
+
+       u8_gc->data = in_8(mm_gc->regs);
+}
+
+static int __init u8_simple_gpiochip_add(struct device_node *np)
+{
+       int ret;
+       struct u8_gpio_chip *u8_gc;
+       struct of_mm_gpio_chip *mm_gc;
+       struct gpio_chip *gc;
+
+       u8_gc = kzalloc(sizeof(*u8_gc), GFP_KERNEL);
+       if (!u8_gc)
+               return -ENOMEM;
+
+       spin_lock_init(&u8_gc->lock);
+
+       mm_gc = &u8_gc->mm_gc;
+       gc = &mm_gc->gc;
+
+       mm_gc->save_regs = u8_gpio_save_regs;
+       gc->ngpio = 8;
+       gc->direction_input = u8_gpio_dir_in;
+       gc->direction_output = u8_gpio_dir_out;
+       gc->get = u8_gpio_get;
+       gc->set = u8_gpio_set;
+
+       ret = of_mm_gpiochip_add(np, mm_gc);
+       if (ret)
+               goto err;
+       return 0;
+err:
+       kfree(u8_gc);
+       return ret;
+}
+
+void __init simple_gpiochip_init(const char *compatible)
+{
+       struct device_node *np;
+
+       for_each_compatible_node(np, NULL, compatible) {
+               int ret;
+               struct resource r;
+
+               ret = of_address_to_resource(np, 0, &r);
+               if (ret)
+                       goto err;
+
+               switch (resource_size(&r)) {
+               case 1:
+                       ret = u8_simple_gpiochip_add(np);
+                       if (ret)
+                               goto err;
+                       break;
+               default:
+                       /*
+                        * Whenever you need support for GPIO bank width > 1,
+                        * please just turn u8_ code into huge macros, and
+                        * construct needed uX_ code with it.
+                        */
+                       ret = -ENOSYS;
+                       goto err;
+               }
+               continue;
+err:
+               pr_err("%s: registration failed, status %d\n",
+                      np->full_name, ret);
+       }
+}