diff options
Diffstat (limited to 'drivers/gpio/gpio-amd-fch.c')
| -rw-r--r-- | drivers/gpio/gpio-amd-fch.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-amd-fch.c b/drivers/gpio/gpio-amd-fch.c new file mode 100644 index 0000000000..2a21354ed6 --- /dev/null +++ b/drivers/gpio/gpio-amd-fch.c @@ -0,0 +1,192 @@ +// SPDX-License-Identifier: GPL-2.0+ + +/* + * GPIO driver for the AMD G series FCH (eg. GX-412TC) + * + * Copyright (C) 2018 metux IT consult + * Author: Enrico Weigelt, metux IT consult <info@metux.net> + * + */ + +#include <linux/err.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/gpio/driver.h> +#include <linux/platform_data/gpio/gpio-amd-fch.h> +#include <linux/spinlock.h> + +#define AMD_FCH_MMIO_BASE 0xFED80000 +#define AMD_FCH_GPIO_BANK0_BASE 0x1500 +#define AMD_FCH_GPIO_SIZE 0x0300 + +#define AMD_FCH_GPIO_FLAG_DIRECTION BIT(23) +#define AMD_FCH_GPIO_FLAG_WRITE BIT(22) +#define AMD_FCH_GPIO_FLAG_READ BIT(16) + +static const struct resource amd_fch_gpio_iores = + DEFINE_RES_MEM_NAMED( + AMD_FCH_MMIO_BASE + AMD_FCH_GPIO_BANK0_BASE, + AMD_FCH_GPIO_SIZE, + "amd-fch-gpio-iomem"); + +struct amd_fch_gpio_priv { + struct gpio_chip gc; + void __iomem *base; + struct amd_fch_gpio_pdata *pdata; + spinlock_t lock; +}; + +static void __iomem *amd_fch_gpio_addr(struct amd_fch_gpio_priv *priv, + unsigned int gpio) +{ + return priv->base + priv->pdata->gpio_reg[gpio]*sizeof(u32); +} + +static int amd_fch_gpio_direction_input(struct gpio_chip *gc, + unsigned int offset) +{ + unsigned long flags; + struct amd_fch_gpio_priv *priv = gpiochip_get_data(gc); + void __iomem *ptr = amd_fch_gpio_addr(priv, offset); + + spin_lock_irqsave(&priv->lock, flags); + writel_relaxed(readl_relaxed(ptr) & ~AMD_FCH_GPIO_FLAG_DIRECTION, ptr); + spin_unlock_irqrestore(&priv->lock, flags); + + return 0; +} + +static int amd_fch_gpio_direction_output(struct gpio_chip *gc, + unsigned int gpio, int value) +{ + unsigned long flags; + struct amd_fch_gpio_priv *priv = gpiochip_get_data(gc); + void __iomem *ptr = amd_fch_gpio_addr(priv, gpio); + u32 val; + + spin_lock_irqsave(&priv->lock, flags); + + val = readl_relaxed(ptr); + if (value) + val |= AMD_FCH_GPIO_FLAG_WRITE; + else + val &= ~AMD_FCH_GPIO_FLAG_WRITE; + + writel_relaxed(val | AMD_FCH_GPIO_FLAG_DIRECTION, ptr); + + spin_unlock_irqrestore(&priv->lock, flags); + + return 0; +} + +static int amd_fch_gpio_get_direction(struct gpio_chip *gc, unsigned int gpio) +{ + int ret; + unsigned long flags; + struct amd_fch_gpio_priv *priv = gpiochip_get_data(gc); + void __iomem *ptr = amd_fch_gpio_addr(priv, gpio); + + spin_lock_irqsave(&priv->lock, flags); + ret = (readl_relaxed(ptr) & AMD_FCH_GPIO_FLAG_DIRECTION); + spin_unlock_irqrestore(&priv->lock, flags); + + return ret ? GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN; +} + +static void amd_fch_gpio_set(struct gpio_chip *gc, + unsigned int gpio, int value) +{ + unsigned long flags; + struct amd_fch_gpio_priv *priv = gpiochip_get_data(gc); + void __iomem *ptr = amd_fch_gpio_addr(priv, gpio); + u32 mask; + + spin_lock_irqsave(&priv->lock, flags); + + mask = readl_relaxed(ptr); + if (value) + mask |= AMD_FCH_GPIO_FLAG_WRITE; + else + mask &= ~AMD_FCH_GPIO_FLAG_WRITE; + writel_relaxed(mask, ptr); + + spin_unlock_irqrestore(&priv->lock, flags); +} + +static int amd_fch_gpio_get(struct gpio_chip *gc, + unsigned int offset) +{ + unsigned long flags; + int ret; + struct amd_fch_gpio_priv *priv = gpiochip_get_data(gc); + void __iomem *ptr = amd_fch_gpio_addr(priv, offset); + + spin_lock_irqsave(&priv->lock, flags); + ret = (readl_relaxed(ptr) & AMD_FCH_GPIO_FLAG_READ); + spin_unlock_irqrestore(&priv->lock, flags); + + return ret; +} + +static int amd_fch_gpio_request(struct gpio_chip *chip, + unsigned int gpio_pin) +{ + return 0; +} + +static int amd_fch_gpio_probe(struct platform_device *pdev) +{ + struct amd_fch_gpio_priv *priv; + struct amd_fch_gpio_pdata *pdata; + + pdata = dev_get_platdata(&pdev->dev); + if (!pdata) { + dev_err(&pdev->dev, "no platform_data\n"); + return -ENOENT; + } + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->pdata = pdata; + + priv->gc.owner = THIS_MODULE; + priv->gc.parent = &pdev->dev; + priv->gc.label = dev_name(&pdev->dev); + priv->gc.ngpio = priv->pdata->gpio_num; + priv->gc.names = priv->pdata->gpio_names; + priv->gc.base = -1; + priv->gc.request = amd_fch_gpio_request; + priv->gc.direction_input = amd_fch_gpio_direction_input; + priv->gc.direction_output = amd_fch_gpio_direction_output; + priv->gc.get_direction = amd_fch_gpio_get_direction; + priv->gc.get = amd_fch_gpio_get; + priv->gc.set = amd_fch_gpio_set; + + spin_lock_init(&priv->lock); + + priv->base = devm_ioremap_resource(&pdev->dev, &amd_fch_gpio_iores); + if (IS_ERR(priv->base)) + return PTR_ERR(priv->base); + + platform_set_drvdata(pdev, priv); + + return devm_gpiochip_add_data(&pdev->dev, &priv->gc, priv); +} + +static struct platform_driver amd_fch_gpio_driver = { + .driver = { + .name = AMD_FCH_GPIO_DRIVER_NAME, + }, + .probe = amd_fch_gpio_probe, +}; + +module_platform_driver(amd_fch_gpio_driver); + +MODULE_AUTHOR("Enrico Weigelt, metux IT consult <info@metux.net>"); +MODULE_DESCRIPTION("AMD G-series FCH GPIO driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:" AMD_FCH_GPIO_DRIVER_NAME); |