diff options
Diffstat (limited to 'drivers/gpio/gpio-loongson1.c')
-rw-r--r-- | drivers/gpio/gpio-loongson1.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-loongson1.c b/drivers/gpio/gpio-loongson1.c new file mode 100644 index 000000000000..10c09bdd8514 --- /dev/null +++ b/drivers/gpio/gpio-loongson1.c @@ -0,0 +1,102 @@ +/* + * GPIO Driver for Loongson 1 SoC + * + * Copyright (C) 2015-2016 Zhang, Keguang <keguang.zhang@gmail.com> + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include <linux/gpio/driver.h> +#include <linux/platform_device.h> + +/* Loongson 1 GPIO Register Definitions */ +#define GPIO_CFG 0x0 +#define GPIO_DIR 0x10 +#define GPIO_DATA 0x20 +#define GPIO_OUTPUT 0x30 + +static void __iomem *gpio_reg_base; + +static int ls1x_gpio_request(struct gpio_chip *gc, unsigned int offset) +{ + unsigned long pinmask = gc->pin2mask(gc, offset); + unsigned long flags; + + spin_lock_irqsave(&gc->bgpio_lock, flags); + __raw_writel(__raw_readl(gpio_reg_base + GPIO_CFG) | pinmask, + gpio_reg_base + GPIO_CFG); + spin_unlock_irqrestore(&gc->bgpio_lock, flags); + + return 0; +} + +static void ls1x_gpio_free(struct gpio_chip *gc, unsigned int offset) +{ + unsigned long pinmask = gc->pin2mask(gc, offset); + unsigned long flags; + + spin_lock_irqsave(&gc->bgpio_lock, flags); + __raw_writel(__raw_readl(gpio_reg_base + GPIO_CFG) & ~pinmask, + gpio_reg_base + GPIO_CFG); + spin_unlock_irqrestore(&gc->bgpio_lock, flags); +} + +static int ls1x_gpio_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct gpio_chip *gc; + struct resource *res; + int ret; + + gc = devm_kzalloc(dev, sizeof(*gc), GFP_KERNEL); + if (!gc) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) { + dev_err(dev, "failed to get I/O memory\n"); + return -EINVAL; + } + + gpio_reg_base = devm_ioremap_resource(dev, res); + if (IS_ERR(gpio_reg_base)) + return PTR_ERR(gpio_reg_base); + + ret = bgpio_init(gc, dev, 4, gpio_reg_base + GPIO_DATA, + gpio_reg_base + GPIO_OUTPUT, NULL, + NULL, gpio_reg_base + GPIO_DIR, 0); + if (ret) + goto err; + + gc->owner = THIS_MODULE; + gc->request = ls1x_gpio_request; + gc->free = ls1x_gpio_free; + gc->base = pdev->id * 32; + + ret = devm_gpiochip_add_data(dev, gc, NULL); + if (ret) + goto err; + + platform_set_drvdata(pdev, gc); + dev_info(dev, "Loongson1 GPIO driver registered\n"); + + return 0; +err: + dev_err(dev, "failed to register GPIO device\n"); + return ret; +} + +static struct platform_driver ls1x_gpio_driver = { + .probe = ls1x_gpio_probe, + .driver = { + .name = "ls1x-gpio", + }, +}; + +module_platform_driver(ls1x_gpio_driver); + +MODULE_AUTHOR("Kelvin Cheung <keguang.zhang@gmail.com>"); +MODULE_DESCRIPTION("Loongson1 GPIO driver"); +MODULE_LICENSE("GPL"); |