linux/arch/powerpc/sysdev/mpc8xxx_gpio.c
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   1/*
   2 * GPIOs on MPC8349/8572/8610 and compatible
   3 *
   4 * Copyright (C) 2008 Peter Korsgaard <jacmet@sunsite.dk>
   5 *
   6 * This file is licensed under the terms of the GNU General Public License
   7 * version 2.  This program is licensed "as is" without any warranty of any
   8 * kind, whether express or implied.
   9 */
  10
  11#include <linux/kernel.h>
  12#include <linux/init.h>
  13#include <linux/spinlock.h>
  14#include <linux/io.h>
  15#include <linux/of.h>
  16#include <linux/of_gpio.h>
  17#include <linux/gpio.h>
  18
  19#define MPC8XXX_GPIO_PINS       32
  20
  21#define GPIO_DIR                0x00
  22#define GPIO_ODR                0x04
  23#define GPIO_DAT                0x08
  24#define GPIO_IER                0x0c
  25#define GPIO_IMR                0x10
  26#define GPIO_ICR                0x14
  27
  28struct mpc8xxx_gpio_chip {
  29        struct of_mm_gpio_chip mm_gc;
  30        spinlock_t lock;
  31
  32        /*
  33         * shadowed data register to be able to clear/set output pins in
  34         * open drain mode safely
  35         */
  36        u32 data;
  37};
  38
  39static inline u32 mpc8xxx_gpio2mask(unsigned int gpio)
  40{
  41        return 1u << (MPC8XXX_GPIO_PINS - 1 - gpio);
  42}
  43
  44static inline struct mpc8xxx_gpio_chip *
  45to_mpc8xxx_gpio_chip(struct of_mm_gpio_chip *mm)
  46{
  47        return container_of(mm, struct mpc8xxx_gpio_chip, mm_gc);
  48}
  49
  50static void mpc8xxx_gpio_save_regs(struct of_mm_gpio_chip *mm)
  51{
  52        struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm);
  53
  54        mpc8xxx_gc->data = in_be32(mm->regs + GPIO_DAT);
  55}
  56
  57static int mpc8xxx_gpio_get(struct gpio_chip *gc, unsigned int gpio)
  58{
  59        struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);
  60
  61        return in_be32(mm->regs + GPIO_DAT) & mpc8xxx_gpio2mask(gpio);
  62}
  63
  64static void mpc8xxx_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
  65{
  66        struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);
  67        struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm);
  68        unsigned long flags;
  69
  70        spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
  71
  72        if (val)
  73                mpc8xxx_gc->data |= mpc8xxx_gpio2mask(gpio);
  74        else
  75                mpc8xxx_gc->data &= ~mpc8xxx_gpio2mask(gpio);
  76
  77        out_be32(mm->regs + GPIO_DAT, mpc8xxx_gc->data);
  78
  79        spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
  80}
  81
  82static int mpc8xxx_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
  83{
  84        struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);
  85        struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm);
  86        unsigned long flags;
  87
  88        spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
  89
  90        clrbits32(mm->regs + GPIO_DIR, mpc8xxx_gpio2mask(gpio));
  91
  92        spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
  93
  94        return 0;
  95}
  96
  97static int mpc8xxx_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
  98{
  99        struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);
 100        struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm);
 101        unsigned long flags;
 102
 103        mpc8xxx_gpio_set(gc, gpio, val);
 104
 105        spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
 106
 107        setbits32(mm->regs + GPIO_DIR, mpc8xxx_gpio2mask(gpio));
 108
 109        spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
 110
 111        return 0;
 112}
 113
 114static void __init mpc8xxx_add_controller(struct device_node *np)
 115{
 116        struct mpc8xxx_gpio_chip *mpc8xxx_gc;
 117        struct of_mm_gpio_chip *mm_gc;
 118        struct of_gpio_chip *of_gc;
 119        struct gpio_chip *gc;
 120        int ret;
 121
 122        mpc8xxx_gc = kzalloc(sizeof(*mpc8xxx_gc), GFP_KERNEL);
 123        if (!mpc8xxx_gc) {
 124                ret = -ENOMEM;
 125                goto err;
 126        }
 127
 128        spin_lock_init(&mpc8xxx_gc->lock);
 129
 130        mm_gc = &mpc8xxx_gc->mm_gc;
 131        of_gc = &mm_gc->of_gc;
 132        gc = &of_gc->gc;
 133
 134        mm_gc->save_regs = mpc8xxx_gpio_save_regs;
 135        of_gc->gpio_cells = 2;
 136        gc->ngpio = MPC8XXX_GPIO_PINS;
 137        gc->direction_input = mpc8xxx_gpio_dir_in;
 138        gc->direction_output = mpc8xxx_gpio_dir_out;
 139        gc->get = mpc8xxx_gpio_get;
 140        gc->set = mpc8xxx_gpio_set;
 141
 142        ret = of_mm_gpiochip_add(np, mm_gc);
 143        if (ret)
 144                goto err;
 145
 146        return;
 147
 148err:
 149        pr_err("%s: registration failed with status %d\n",
 150               np->full_name, ret);
 151        kfree(mpc8xxx_gc);
 152
 153        return;
 154}
 155
 156static int __init mpc8xxx_add_gpiochips(void)
 157{
 158        struct device_node *np;
 159
 160        for_each_compatible_node(np, NULL, "fsl,mpc8349-gpio")
 161                mpc8xxx_add_controller(np);
 162
 163        for_each_compatible_node(np, NULL, "fsl,mpc8572-gpio")
 164                mpc8xxx_add_controller(np);
 165
 166        for_each_compatible_node(np, NULL, "fsl,mpc8610-gpio")
 167                mpc8xxx_add_controller(np);
 168
 169        return 0;
 170}
 171arch_initcall(mpc8xxx_add_gpiochips);
 172