diff options
Diffstat (limited to 'drivers/gpio/gpio-mb86s7x.c')
| -rw-r--r-- | drivers/gpio/gpio-mb86s7x.c | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-mb86s7x.c b/drivers/gpio/gpio-mb86s7x.c new file mode 100644 index 000000000..ee93c0ab0 --- /dev/null +++ b/drivers/gpio/gpio-mb86s7x.c @@ -0,0 +1,237 @@ +/* + * linux/drivers/gpio/gpio-mb86s7x.c + * + * Copyright (C) 2015 Fujitsu Semiconductor Limited + * Copyright (C) 2015 Linaro Ltd. + * + * 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, version 2 of the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/io.h> +#include <linux/init.h> +#include <linux/clk.h> +#include <linux/module.h> +#include <linux/err.h> +#include <linux/errno.h> +#include <linux/ioport.h> +#include <linux/of_device.h> +#include <linux/gpio/driver.h> +#include <linux/platform_device.h> +#include <linux/spinlock.h> +#include <linux/slab.h> + +/* + * Only first 8bits of a register correspond to each pin, + * so there are 4 registers for 32 pins. + */ +#define PDR(x) (0x0 + x / 8 * 4) +#define DDR(x) (0x10 + x / 8 * 4) +#define PFR(x) (0x20 + x / 8 * 4) + +#define OFFSET(x) BIT((x) % 8) + +struct mb86s70_gpio_chip { + struct gpio_chip gc; + void __iomem *base; + struct clk *clk; + spinlock_t lock; +}; + +static inline struct mb86s70_gpio_chip *chip_to_mb86s70(struct gpio_chip *gc) +{ + return container_of(gc, struct mb86s70_gpio_chip, gc); +} + +static int mb86s70_gpio_request(struct gpio_chip *gc, unsigned gpio) +{ + struct mb86s70_gpio_chip *gchip = chip_to_mb86s70(gc); + unsigned long flags; + u32 val; + + spin_lock_irqsave(&gchip->lock, flags); + + val = readl(gchip->base + PFR(gpio)); + if (!(val & OFFSET(gpio))) { + spin_unlock_irqrestore(&gchip->lock, flags); + return -EINVAL; + } + + val &= ~OFFSET(gpio); + writel(val, gchip->base + PFR(gpio)); + + spin_unlock_irqrestore(&gchip->lock, flags); + + return 0; +} + +static void mb86s70_gpio_free(struct gpio_chip *gc, unsigned gpio) +{ + struct mb86s70_gpio_chip *gchip = chip_to_mb86s70(gc); + unsigned long flags; + u32 val; + + spin_lock_irqsave(&gchip->lock, flags); + + val = readl(gchip->base + PFR(gpio)); + val |= OFFSET(gpio); + writel(val, gchip->base + PFR(gpio)); + + spin_unlock_irqrestore(&gchip->lock, flags); +} + +static int mb86s70_gpio_direction_input(struct gpio_chip *gc, unsigned gpio) +{ + struct mb86s70_gpio_chip *gchip = chip_to_mb86s70(gc); + unsigned long flags; + unsigned char val; + + spin_lock_irqsave(&gchip->lock, flags); + + val = readl(gchip->base + DDR(gpio)); + val &= ~OFFSET(gpio); + writel(val, gchip->base + DDR(gpio)); + + spin_unlock_irqrestore(&gchip->lock, flags); + + return 0; +} + +static int mb86s70_gpio_direction_output(struct gpio_chip *gc, + unsigned gpio, int value) +{ + struct mb86s70_gpio_chip *gchip = chip_to_mb86s70(gc); + unsigned long flags; + unsigned char val; + + spin_lock_irqsave(&gchip->lock, flags); + + val = readl(gchip->base + PDR(gpio)); + if (value) + val |= OFFSET(gpio); + else + val &= ~OFFSET(gpio); + writel(val, gchip->base + PDR(gpio)); + + val = readl(gchip->base + DDR(gpio)); + val |= OFFSET(gpio); + writel(val, gchip->base + DDR(gpio)); + + spin_unlock_irqrestore(&gchip->lock, flags); + + return 0; +} + +static int mb86s70_gpio_get(struct gpio_chip *gc, unsigned gpio) +{ + struct mb86s70_gpio_chip *gchip = chip_to_mb86s70(gc); + + return !!(readl(gchip->base + PDR(gpio)) & OFFSET(gpio)); +} + +static void mb86s70_gpio_set(struct gpio_chip *gc, unsigned gpio, int value) +{ + struct mb86s70_gpio_chip *gchip = chip_to_mb86s70(gc); + unsigned long flags; + unsigned char val; + + spin_lock_irqsave(&gchip->lock, flags); + + val = readl(gchip->base + PDR(gpio)); + if (value) + val |= OFFSET(gpio); + else + val &= ~OFFSET(gpio); + writel(val, gchip->base + PDR(gpio)); + + spin_unlock_irqrestore(&gchip->lock, flags); +} + +static int mb86s70_gpio_probe(struct platform_device *pdev) +{ + struct mb86s70_gpio_chip *gchip; + struct resource *res; + int ret; + + gchip = devm_kzalloc(&pdev->dev, sizeof(*gchip), GFP_KERNEL); + if (gchip == NULL) + return -ENOMEM; + + platform_set_drvdata(pdev, gchip); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + gchip->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(gchip->base)) + return PTR_ERR(gchip->base); + + gchip->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(gchip->clk)) + return PTR_ERR(gchip->clk); + + clk_prepare_enable(gchip->clk); + + spin_lock_init(&gchip->lock); + + gchip->gc.direction_output = mb86s70_gpio_direction_output; + gchip->gc.direction_input = mb86s70_gpio_direction_input; + gchip->gc.request = mb86s70_gpio_request; + gchip->gc.free = mb86s70_gpio_free; + gchip->gc.get = mb86s70_gpio_get; + gchip->gc.set = mb86s70_gpio_set; + gchip->gc.label = dev_name(&pdev->dev); + gchip->gc.ngpio = 32; + gchip->gc.owner = THIS_MODULE; + gchip->gc.dev = &pdev->dev; + gchip->gc.base = -1; + + platform_set_drvdata(pdev, gchip); + + ret = gpiochip_add(&gchip->gc); + if (ret) { + dev_err(&pdev->dev, "couldn't register gpio driver\n"); + clk_disable_unprepare(gchip->clk); + } + + return ret; +} + +static int mb86s70_gpio_remove(struct platform_device *pdev) +{ + struct mb86s70_gpio_chip *gchip = platform_get_drvdata(pdev); + + gpiochip_remove(&gchip->gc); + clk_disable_unprepare(gchip->clk); + + return 0; +} + +static const struct of_device_id mb86s70_gpio_dt_ids[] = { + { .compatible = "fujitsu,mb86s70-gpio" }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, mb86s70_gpio_dt_ids); + +static struct platform_driver mb86s70_gpio_driver = { + .driver = { + .name = "mb86s70-gpio", + .of_match_table = mb86s70_gpio_dt_ids, + }, + .probe = mb86s70_gpio_probe, + .remove = mb86s70_gpio_remove, +}; + +static int __init mb86s70_gpio_init(void) +{ + return platform_driver_register(&mb86s70_gpio_driver); +} +module_init(mb86s70_gpio_init); + +MODULE_DESCRIPTION("MB86S7x GPIO Driver"); +MODULE_ALIAS("platform:mb86s70-gpio"); +MODULE_LICENSE("GPL"); |