linux/drivers/gpio/gpio-da9055.c
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   1/*
   2 * GPIO Driver for Dialog DA9055 PMICs.
   3 *
   4 * Copyright(c) 2012 Dialog Semiconductor Ltd.
   5 *
   6 * Author: David Dajun Chen <dchen@diasemi.com>
   7 *
   8 *  This program is free software; you can redistribute  it and/or modify it
   9 *  under  the terms of  the GNU General  Public License as published by the
  10 *  Free Software Foundation;  either version 2 of the  License, or (at your
  11 *  option) any later version.
  12 *
  13 */
  14#include <linux/module.h>
  15#include <linux/platform_device.h>
  16#include <linux/gpio.h>
  17
  18#include <linux/mfd/da9055/core.h>
  19#include <linux/mfd/da9055/reg.h>
  20#include <linux/mfd/da9055/pdata.h>
  21
  22#define DA9055_VDD_IO                   0x0
  23#define DA9055_PUSH_PULL                0x3
  24#define DA9055_ACT_LOW                  0x0
  25#define DA9055_GPI                      0x1
  26#define DA9055_PORT_MASK                0x3
  27#define DA9055_PORT_SHIFT(offset)       (4 * (offset % 2))
  28
  29#define DA9055_INPUT                    DA9055_GPI
  30#define DA9055_OUTPUT                   DA9055_PUSH_PULL
  31#define DA9055_IRQ_GPI0                 3
  32
  33struct da9055_gpio {
  34        struct da9055 *da9055;
  35        struct gpio_chip gp;
  36};
  37
  38static int da9055_gpio_get(struct gpio_chip *gc, unsigned offset)
  39{
  40        struct da9055_gpio *gpio = gpiochip_get_data(gc);
  41        int gpio_direction = 0;
  42        int ret;
  43
  44        /* Get GPIO direction */
  45        ret = da9055_reg_read(gpio->da9055, (offset >> 1) + DA9055_REG_GPIO0_1);
  46        if (ret < 0)
  47                return ret;
  48
  49        gpio_direction = ret & (DA9055_PORT_MASK) << DA9055_PORT_SHIFT(offset);
  50        gpio_direction >>= DA9055_PORT_SHIFT(offset);
  51        switch (gpio_direction) {
  52        case DA9055_INPUT:
  53                ret = da9055_reg_read(gpio->da9055, DA9055_REG_STATUS_B);
  54                if (ret < 0)
  55                        return ret;
  56                break;
  57        case DA9055_OUTPUT:
  58                ret = da9055_reg_read(gpio->da9055, DA9055_REG_GPIO_MODE0_2);
  59                if (ret < 0)
  60                        return ret;
  61        }
  62
  63        return ret & (1 << offset);
  64
  65}
  66
  67static void da9055_gpio_set(struct gpio_chip *gc, unsigned offset, int value)
  68{
  69        struct da9055_gpio *gpio = gpiochip_get_data(gc);
  70
  71        da9055_reg_update(gpio->da9055,
  72                        DA9055_REG_GPIO_MODE0_2,
  73                        1 << offset,
  74                        value << offset);
  75}
  76
  77static int da9055_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
  78{
  79        struct da9055_gpio *gpio = gpiochip_get_data(gc);
  80        unsigned char reg_byte;
  81
  82        reg_byte = (DA9055_ACT_LOW | DA9055_GPI)
  83                                << DA9055_PORT_SHIFT(offset);
  84
  85        return da9055_reg_update(gpio->da9055, (offset >> 1) +
  86                                DA9055_REG_GPIO0_1,
  87                                DA9055_PORT_MASK <<
  88                                DA9055_PORT_SHIFT(offset),
  89                                reg_byte);
  90}
  91
  92static int da9055_gpio_direction_output(struct gpio_chip *gc,
  93                                        unsigned offset, int value)
  94{
  95        struct da9055_gpio *gpio = gpiochip_get_data(gc);
  96        unsigned char reg_byte;
  97        int ret;
  98
  99        reg_byte = (DA9055_VDD_IO | DA9055_PUSH_PULL)
 100                                        << DA9055_PORT_SHIFT(offset);
 101
 102        ret = da9055_reg_update(gpio->da9055, (offset >> 1) +
 103                                DA9055_REG_GPIO0_1,
 104                                DA9055_PORT_MASK <<
 105                                DA9055_PORT_SHIFT(offset),
 106                                reg_byte);
 107        if (ret < 0)
 108                return ret;
 109
 110        da9055_gpio_set(gc, offset, value);
 111
 112        return 0;
 113}
 114
 115static int da9055_gpio_to_irq(struct gpio_chip *gc, u32 offset)
 116{
 117        struct da9055_gpio *gpio = gpiochip_get_data(gc);
 118        struct da9055 *da9055 = gpio->da9055;
 119
 120        return regmap_irq_get_virq(da9055->irq_data,
 121                                  DA9055_IRQ_GPI0 + offset);
 122}
 123
 124static struct gpio_chip reference_gp = {
 125        .label = "da9055-gpio",
 126        .owner = THIS_MODULE,
 127        .get = da9055_gpio_get,
 128        .set = da9055_gpio_set,
 129        .direction_input = da9055_gpio_direction_input,
 130        .direction_output = da9055_gpio_direction_output,
 131        .to_irq = da9055_gpio_to_irq,
 132        .can_sleep = true,
 133        .ngpio = 3,
 134        .base = -1,
 135};
 136
 137static int da9055_gpio_probe(struct platform_device *pdev)
 138{
 139        struct da9055_gpio *gpio;
 140        struct da9055_pdata *pdata;
 141        int ret;
 142
 143        gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
 144        if (!gpio)
 145                return -ENOMEM;
 146
 147        gpio->da9055 = dev_get_drvdata(pdev->dev.parent);
 148        pdata = dev_get_platdata(gpio->da9055->dev);
 149
 150        gpio->gp = reference_gp;
 151        if (pdata && pdata->gpio_base)
 152                gpio->gp.base = pdata->gpio_base;
 153
 154        ret = devm_gpiochip_add_data(&pdev->dev, &gpio->gp, gpio);
 155        if (ret < 0) {
 156                dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
 157                return ret;
 158        }
 159
 160        platform_set_drvdata(pdev, gpio);
 161
 162        return 0;
 163}
 164
 165static struct platform_driver da9055_gpio_driver = {
 166        .probe = da9055_gpio_probe,
 167        .driver = {
 168                .name   = "da9055-gpio",
 169        },
 170};
 171
 172static int __init da9055_gpio_init(void)
 173{
 174        return platform_driver_register(&da9055_gpio_driver);
 175}
 176subsys_initcall(da9055_gpio_init);
 177
 178static void __exit da9055_gpio_exit(void)
 179{
 180        platform_driver_unregister(&da9055_gpio_driver);
 181}
 182module_exit(da9055_gpio_exit);
 183
 184MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
 185MODULE_DESCRIPTION("DA9055 GPIO Device Driver");
 186MODULE_LICENSE("GPL");
 187MODULE_ALIAS("platform:da9055-gpio");
 188