linux/drivers/gpio/gpio-mb86s7x.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *  linux/drivers/gpio/gpio-mb86s7x.c
   4 *
   5 *  Copyright (C) 2015 Fujitsu Semiconductor Limited
   6 *  Copyright (C) 2015 Linaro Ltd.
   7 */
   8
   9#include <linux/acpi.h>
  10#include <linux/io.h>
  11#include <linux/init.h>
  12#include <linux/clk.h>
  13#include <linux/module.h>
  14#include <linux/err.h>
  15#include <linux/errno.h>
  16#include <linux/ioport.h>
  17#include <linux/of_device.h>
  18#include <linux/gpio/driver.h>
  19#include <linux/platform_device.h>
  20#include <linux/spinlock.h>
  21#include <linux/slab.h>
  22
  23#include "gpiolib.h"
  24#include "gpiolib-acpi.h"
  25
  26/*
  27 * Only first 8bits of a register correspond to each pin,
  28 * so there are 4 registers for 32 pins.
  29 */
  30#define PDR(x)  (0x0 + x / 8 * 4)
  31#define DDR(x)  (0x10 + x / 8 * 4)
  32#define PFR(x)  (0x20 + x / 8 * 4)
  33
  34#define OFFSET(x)       BIT((x) % 8)
  35
  36struct mb86s70_gpio_chip {
  37        struct gpio_chip gc;
  38        void __iomem *base;
  39        struct clk *clk;
  40        spinlock_t lock;
  41};
  42
  43static int mb86s70_gpio_request(struct gpio_chip *gc, unsigned gpio)
  44{
  45        struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc);
  46        unsigned long flags;
  47        u32 val;
  48
  49        spin_lock_irqsave(&gchip->lock, flags);
  50
  51        val = readl(gchip->base + PFR(gpio));
  52        val &= ~OFFSET(gpio);
  53        writel(val, gchip->base + PFR(gpio));
  54
  55        spin_unlock_irqrestore(&gchip->lock, flags);
  56
  57        return 0;
  58}
  59
  60static void mb86s70_gpio_free(struct gpio_chip *gc, unsigned gpio)
  61{
  62        struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc);
  63        unsigned long flags;
  64        u32 val;
  65
  66        spin_lock_irqsave(&gchip->lock, flags);
  67
  68        val = readl(gchip->base + PFR(gpio));
  69        val |= OFFSET(gpio);
  70        writel(val, gchip->base + PFR(gpio));
  71
  72        spin_unlock_irqrestore(&gchip->lock, flags);
  73}
  74
  75static int mb86s70_gpio_direction_input(struct gpio_chip *gc, unsigned gpio)
  76{
  77        struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc);
  78        unsigned long flags;
  79        unsigned char val;
  80
  81        spin_lock_irqsave(&gchip->lock, flags);
  82
  83        val = readl(gchip->base + DDR(gpio));
  84        val &= ~OFFSET(gpio);
  85        writel(val, gchip->base + DDR(gpio));
  86
  87        spin_unlock_irqrestore(&gchip->lock, flags);
  88
  89        return 0;
  90}
  91
  92static int mb86s70_gpio_direction_output(struct gpio_chip *gc,
  93                                         unsigned gpio, int value)
  94{
  95        struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc);
  96        unsigned long flags;
  97        unsigned char val;
  98
  99        spin_lock_irqsave(&gchip->lock, flags);
 100
 101        val = readl(gchip->base + PDR(gpio));
 102        if (value)
 103                val |= OFFSET(gpio);
 104        else
 105                val &= ~OFFSET(gpio);
 106        writel(val, gchip->base + PDR(gpio));
 107
 108        val = readl(gchip->base + DDR(gpio));
 109        val |= OFFSET(gpio);
 110        writel(val, gchip->base + DDR(gpio));
 111
 112        spin_unlock_irqrestore(&gchip->lock, flags);
 113
 114        return 0;
 115}
 116
 117static int mb86s70_gpio_get(struct gpio_chip *gc, unsigned gpio)
 118{
 119        struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc);
 120
 121        return !!(readl(gchip->base + PDR(gpio)) & OFFSET(gpio));
 122}
 123
 124static void mb86s70_gpio_set(struct gpio_chip *gc, unsigned gpio, int value)
 125{
 126        struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc);
 127        unsigned long flags;
 128        unsigned char val;
 129
 130        spin_lock_irqsave(&gchip->lock, flags);
 131
 132        val = readl(gchip->base + PDR(gpio));
 133        if (value)
 134                val |= OFFSET(gpio);
 135        else
 136                val &= ~OFFSET(gpio);
 137        writel(val, gchip->base + PDR(gpio));
 138
 139        spin_unlock_irqrestore(&gchip->lock, flags);
 140}
 141
 142static int mb86s70_gpio_to_irq(struct gpio_chip *gc, unsigned int offset)
 143{
 144        int irq, index;
 145
 146        for (index = 0;; index++) {
 147                irq = platform_get_irq(to_platform_device(gc->parent), index);
 148                if (irq < 0)
 149                        return irq;
 150                if (irq == 0)
 151                        break;
 152                if (irq_get_irq_data(irq)->hwirq == offset)
 153                        return irq;
 154        }
 155        return -EINVAL;
 156}
 157
 158static int mb86s70_gpio_probe(struct platform_device *pdev)
 159{
 160        struct mb86s70_gpio_chip *gchip;
 161        int ret;
 162
 163        gchip = devm_kzalloc(&pdev->dev, sizeof(*gchip), GFP_KERNEL);
 164        if (gchip == NULL)
 165                return -ENOMEM;
 166
 167        platform_set_drvdata(pdev, gchip);
 168
 169        gchip->base = devm_platform_ioremap_resource(pdev, 0);
 170        if (IS_ERR(gchip->base))
 171                return PTR_ERR(gchip->base);
 172
 173        gchip->clk = devm_clk_get_optional(&pdev->dev, NULL);
 174        if (IS_ERR(gchip->clk))
 175                return PTR_ERR(gchip->clk);
 176
 177        ret = clk_prepare_enable(gchip->clk);
 178        if (ret)
 179                return ret;
 180
 181        spin_lock_init(&gchip->lock);
 182
 183        gchip->gc.direction_output = mb86s70_gpio_direction_output;
 184        gchip->gc.direction_input = mb86s70_gpio_direction_input;
 185        gchip->gc.request = mb86s70_gpio_request;
 186        gchip->gc.free = mb86s70_gpio_free;
 187        gchip->gc.get = mb86s70_gpio_get;
 188        gchip->gc.set = mb86s70_gpio_set;
 189        gchip->gc.to_irq = mb86s70_gpio_to_irq;
 190        gchip->gc.label = dev_name(&pdev->dev);
 191        gchip->gc.ngpio = 32;
 192        gchip->gc.owner = THIS_MODULE;
 193        gchip->gc.parent = &pdev->dev;
 194        gchip->gc.base = -1;
 195
 196        ret = gpiochip_add_data(&gchip->gc, gchip);
 197        if (ret) {
 198                dev_err(&pdev->dev, "couldn't register gpio driver\n");
 199                clk_disable_unprepare(gchip->clk);
 200                return ret;
 201        }
 202
 203        acpi_gpiochip_request_interrupts(&gchip->gc);
 204
 205        return 0;
 206}
 207
 208static int mb86s70_gpio_remove(struct platform_device *pdev)
 209{
 210        struct mb86s70_gpio_chip *gchip = platform_get_drvdata(pdev);
 211
 212        acpi_gpiochip_free_interrupts(&gchip->gc);
 213        gpiochip_remove(&gchip->gc);
 214        clk_disable_unprepare(gchip->clk);
 215
 216        return 0;
 217}
 218
 219static const struct of_device_id mb86s70_gpio_dt_ids[] = {
 220        { .compatible = "fujitsu,mb86s70-gpio" },
 221        { /* sentinel */ }
 222};
 223MODULE_DEVICE_TABLE(of, mb86s70_gpio_dt_ids);
 224
 225#ifdef CONFIG_ACPI
 226static const struct acpi_device_id mb86s70_gpio_acpi_ids[] = {
 227        { "SCX0007" },
 228        { /* sentinel */ }
 229};
 230MODULE_DEVICE_TABLE(acpi, mb86s70_gpio_acpi_ids);
 231#endif
 232
 233static struct platform_driver mb86s70_gpio_driver = {
 234        .driver = {
 235                .name = "mb86s70-gpio",
 236                .of_match_table = mb86s70_gpio_dt_ids,
 237                .acpi_match_table = ACPI_PTR(mb86s70_gpio_acpi_ids),
 238        },
 239        .probe = mb86s70_gpio_probe,
 240        .remove = mb86s70_gpio_remove,
 241};
 242module_platform_driver(mb86s70_gpio_driver);
 243
 244MODULE_DESCRIPTION("MB86S7x GPIO Driver");
 245MODULE_ALIAS("platform:mb86s70-gpio");
 246MODULE_LICENSE("GPL");
 247