diff options
Diffstat (limited to 'kernel/drivers/gpio/gpio-ath79.c')
| -rw-r--r-- | kernel/drivers/gpio/gpio-ath79.c | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/kernel/drivers/gpio/gpio-ath79.c b/kernel/drivers/gpio/gpio-ath79.c new file mode 100644 index 000000000..5eaea8b81 --- /dev/null +++ b/kernel/drivers/gpio/gpio-ath79.c @@ -0,0 +1,205 @@ +/* + * Atheros AR71XX/AR724X/AR913X GPIO API support + * + * Copyright (C) 2010-2011 Jaiganesh Narayanan <jnarayanan@atheros.com> + * Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org> + * Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org> + * + * Parts of this file are based on Atheros' 2.6.15/2.6.31 BSP + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published + * by the Free Software Foundation. + */ + +#include <linux/gpio/driver.h> +#include <linux/platform_data/gpio-ath79.h> +#include <linux/of_device.h> + +#include <asm/mach-ath79/ar71xx_regs.h> + +struct ath79_gpio_ctrl { + struct gpio_chip chip; + void __iomem *base; + spinlock_t lock; +}; + +#define to_ath79_gpio_ctrl(c) container_of(c, struct ath79_gpio_ctrl, chip) + +static void ath79_gpio_set_value(struct gpio_chip *chip, + unsigned gpio, int value) +{ + struct ath79_gpio_ctrl *ctrl = to_ath79_gpio_ctrl(chip); + + if (value) + __raw_writel(BIT(gpio), ctrl->base + AR71XX_GPIO_REG_SET); + else + __raw_writel(BIT(gpio), ctrl->base + AR71XX_GPIO_REG_CLEAR); +} + +static int ath79_gpio_get_value(struct gpio_chip *chip, unsigned gpio) +{ + struct ath79_gpio_ctrl *ctrl = to_ath79_gpio_ctrl(chip); + + return (__raw_readl(ctrl->base + AR71XX_GPIO_REG_IN) >> gpio) & 1; +} + +static int ath79_gpio_direction_input(struct gpio_chip *chip, + unsigned offset) +{ + struct ath79_gpio_ctrl *ctrl = to_ath79_gpio_ctrl(chip); + unsigned long flags; + + spin_lock_irqsave(&ctrl->lock, flags); + + __raw_writel( + __raw_readl(ctrl->base + AR71XX_GPIO_REG_OE) & ~BIT(offset), + ctrl->base + AR71XX_GPIO_REG_OE); + + spin_unlock_irqrestore(&ctrl->lock, flags); + + return 0; +} + +static int ath79_gpio_direction_output(struct gpio_chip *chip, + unsigned offset, int value) +{ + struct ath79_gpio_ctrl *ctrl = to_ath79_gpio_ctrl(chip); + unsigned long flags; + + spin_lock_irqsave(&ctrl->lock, flags); + + if (value) + __raw_writel(BIT(offset), ctrl->base + AR71XX_GPIO_REG_SET); + else + __raw_writel(BIT(offset), ctrl->base + AR71XX_GPIO_REG_CLEAR); + + __raw_writel( + __raw_readl(ctrl->base + AR71XX_GPIO_REG_OE) | BIT(offset), + ctrl->base + AR71XX_GPIO_REG_OE); + + spin_unlock_irqrestore(&ctrl->lock, flags); + + return 0; +} + +static int ar934x_gpio_direction_input(struct gpio_chip *chip, unsigned offset) +{ + struct ath79_gpio_ctrl *ctrl = to_ath79_gpio_ctrl(chip); + unsigned long flags; + + spin_lock_irqsave(&ctrl->lock, flags); + + __raw_writel( + __raw_readl(ctrl->base + AR71XX_GPIO_REG_OE) | BIT(offset), + ctrl->base + AR71XX_GPIO_REG_OE); + + spin_unlock_irqrestore(&ctrl->lock, flags); + + return 0; +} + +static int ar934x_gpio_direction_output(struct gpio_chip *chip, unsigned offset, + int value) +{ + struct ath79_gpio_ctrl *ctrl = to_ath79_gpio_ctrl(chip); + unsigned long flags; + + spin_lock_irqsave(&ctrl->lock, flags); + + if (value) + __raw_writel(BIT(offset), ctrl->base + AR71XX_GPIO_REG_SET); + else + __raw_writel(BIT(offset), ctrl->base + AR71XX_GPIO_REG_CLEAR); + + __raw_writel( + __raw_readl(ctrl->base + AR71XX_GPIO_REG_OE) & ~BIT(offset), + ctrl->base + AR71XX_GPIO_REG_OE); + + spin_unlock_irqrestore(&ctrl->lock, flags); + + return 0; +} + +static const struct gpio_chip ath79_gpio_chip = { + .label = "ath79", + .get = ath79_gpio_get_value, + .set = ath79_gpio_set_value, + .direction_input = ath79_gpio_direction_input, + .direction_output = ath79_gpio_direction_output, + .base = 0, +}; + +static const struct of_device_id ath79_gpio_of_match[] = { + { .compatible = "qca,ar7100-gpio" }, + { .compatible = "qca,ar9340-gpio" }, + {}, +}; + +static int ath79_gpio_probe(struct platform_device *pdev) +{ + struct ath79_gpio_platform_data *pdata = pdev->dev.platform_data; + struct device_node *np = pdev->dev.of_node; + struct ath79_gpio_ctrl *ctrl; + struct resource *res; + u32 ath79_gpio_count; + bool oe_inverted; + int err; + + ctrl = devm_kzalloc(&pdev->dev, sizeof(*ctrl), GFP_KERNEL); + if (!ctrl) + return -ENOMEM; + + if (np) { + err = of_property_read_u32(np, "ngpios", &ath79_gpio_count); + if (err) { + dev_err(&pdev->dev, "ngpios property is not valid\n"); + return err; + } + if (ath79_gpio_count >= 32) { + dev_err(&pdev->dev, "ngpios must be less than 32\n"); + return -EINVAL; + } + oe_inverted = of_device_is_compatible(np, "qca,ar9340-gpio"); + } else if (pdata) { + ath79_gpio_count = pdata->ngpios; + oe_inverted = pdata->oe_inverted; + } else { + dev_err(&pdev->dev, "No DT node or platform data found\n"); + return -EINVAL; + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + ctrl->base = devm_ioremap_nocache( + &pdev->dev, res->start, resource_size(res)); + if (!ctrl->base) + return -ENOMEM; + + spin_lock_init(&ctrl->lock); + memcpy(&ctrl->chip, &ath79_gpio_chip, sizeof(ctrl->chip)); + ctrl->chip.dev = &pdev->dev; + ctrl->chip.ngpio = ath79_gpio_count; + if (oe_inverted) { + ctrl->chip.direction_input = ar934x_gpio_direction_input; + ctrl->chip.direction_output = ar934x_gpio_direction_output; + } + + err = gpiochip_add(&ctrl->chip); + if (err) { + dev_err(&pdev->dev, + "cannot add AR71xx GPIO chip, error=%d", err); + return err; + } + + return 0; +} + +static struct platform_driver ath79_gpio_driver = { + .driver = { + .name = "ath79-gpio", + .of_match_table = ath79_gpio_of_match, + }, + .probe = ath79_gpio_probe, +}; + +module_platform_driver(ath79_gpio_driver); |