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 inline struct da9055_gpio *to_da9055_gpio(struct gpio_chip *chip)
  39{
  40        return container_of(chip, struct da9055_gpio, gp);
  41}
  42
  43static int da9055_gpio_get(struct gpio_chip *gc, unsigned offset)
  44{
  45        struct da9055_gpio *gpio = to_da9055_gpio(gc);
  46        int gpio_direction = 0;
  47        int ret;
  48
  49        /* Get GPIO direction */
  50        ret = da9055_reg_read(gpio->da9055, (offset >> 1) + DA9055_REG_GPIO0_1);
  51        if (ret < 0)
  52                return ret;
  53
  54        gpio_direction = ret & (DA9055_PORT_MASK) << DA9055_PORT_SHIFT(offset);
  55        gpio_direction >>= DA9055_PORT_SHIFT(offset);
  56        switch (gpio_direction) {
  57        case DA9055_INPUT:
  58                ret = da9055_reg_read(gpio->da9055, DA9055_REG_STATUS_B);
  59                if (ret < 0)
  60                        return ret;
  61                break;
  62        case DA9055_OUTPUT:
  63                ret = da9055_reg_read(gpio->da9055, DA9055_REG_GPIO_MODE0_2);
  64                if (ret < 0)
  65                        return ret;
  66        }
  67
  68        return ret & (1 << offset);
  69
  70}
  71
  72static void da9055_gpio_set(struct gpio_chip *gc, unsigned offset, int value)
  73{
  74        struct da9055_gpio *gpio = to_da9055_gpio(gc);
  75
  76        da9055_reg_update(gpio->da9055,
  77                        DA9055_REG_GPIO_MODE0_2,
  78                        1 << offset,
  79                        value << offset);
  80}
  81
  82static int da9055_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
  83{
  84        struct da9055_gpio *gpio = to_da9055_gpio(gc);
  85        unsigned char reg_byte;
  86
  87        reg_byte = (DA9055_ACT_LOW | DA9055_GPI)
  88                                << DA9055_PORT_SHIFT(offset);
  89
  90        return da9055_reg_update(gpio->da9055, (offset >> 1) +
  91                                DA9055_REG_GPIO0_1,
  92                                DA9055_PORT_MASK <<
  93                                DA9055_PORT_SHIFT(offset),
  94                                reg_byte);
  95}
  96
  97static int da9055_gpio_direction_output(struct gpio_chip *gc,
  98                                        unsigned offset, int value)
  99{
 100        struct da9055_gpio *gpio = to_da9055_gpio(gc);
 101        unsigned char reg_byte;
 102        int ret;
 103
 104        reg_byte = (DA9055_VDD_IO | DA9055_PUSH_PULL)
 105                                        << DA9055_PORT_SHIFT(offset);
 106
 107        ret = da9055_reg_update(gpio->da9055, (offset >> 1) +
 108                                DA9055_REG_GPIO0_1,
 109                                DA9055_PORT_MASK <<
 110                                DA9055_PORT_SHIFT(offset),
 111                                reg_byte);
 112        if (ret < 0)
 113                return ret;
 114
 115        da9055_gpio_set(gc, offset, value);
 116
 117        return 0;
 118}
 119
 120static int da9055_gpio_to_irq(struct gpio_chip *gc, u32 offset)
 121{
 122        struct da9055_gpio *gpio = to_da9055_gpio(gc);
 123        struct da9055 *da9055 = gpio->da9055;
 124
 125        return regmap_irq_get_virq(da9055->irq_data,
 126                                  DA9055_IRQ_GPI0 + offset);
 127}
 128
 129static struct gpio_chip reference_gp = {
 130        .label = "da9055-gpio",
 131        .owner = THIS_MODULE,
 132        .get = da9055_gpio_get,
 133        .set = da9055_gpio_set,
 134        .direction_input = da9055_gpio_direction_input,
 135        .direction_output = da9055_gpio_direction_output,
 136        .to_irq = da9055_gpio_to_irq,
 137        .can_sleep = 1,
 138        .ngpio = 3,
 139        .base = -1,
 140};
 141
 142static int da9055_gpio_probe(struct platform_device *pdev)
 143{
 144        struct da9055_gpio *gpio;
 145        struct da9055_pdata *pdata;
 146        int ret;
 147
 148        gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
 149        if (gpio == NULL)
 150                return -ENOMEM;
 151
 152        gpio->da9055 = dev_get_drvdata(pdev->dev.parent);
 153        pdata = gpio->da9055->dev->platform_data;
 154
 155        gpio->gp = reference_gp;
 156        if (pdata && pdata->gpio_base)
 157                gpio->gp.base = pdata->gpio_base;
 158
 159        ret = gpiochip_add(&gpio->gp);
 160        if (ret < 0) {
 161                dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
 162                goto err_mem;
 163        }
 164
 165        platform_set_drvdata(pdev, gpio);
 166
 167        return 0;
 168
 169err_mem:
 170        return ret;
 171}
 172
 173static int da9055_gpio_remove(struct platform_device *pdev)
 174{
 175        struct da9055_gpio *gpio = platform_get_drvdata(pdev);
 176
 177        return gpiochip_remove(&gpio->gp);
 178}
 179
 180static struct platform_driver da9055_gpio_driver = {
 181        .probe = da9055_gpio_probe,
 182        .remove = da9055_gpio_remove,
 183        .driver = {
 184                .name   = "da9055-gpio",
 185                .owner  = THIS_MODULE,
 186        },
 187};
 188
 189static int __init da9055_gpio_init(void)
 190{
 191        return platform_driver_register(&da9055_gpio_driver);
 192}
 193subsys_initcall(da9055_gpio_init);
 194
 195static void __exit da9055_gpio_exit(void)
 196{
 197        platform_driver_unregister(&da9055_gpio_driver);
 198}
 199module_exit(da9055_gpio_exit);
 200
 201MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
 202MODULE_DESCRIPTION("DA9055 GPIO Device Driver");
 203MODULE_LICENSE("GPL");
 204MODULE_ALIAS("platform:da9055-gpio");
 205
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