diff options
Diffstat (limited to 'drivers/gpio/gpio-xgene.c')
| -rw-r--r-- | drivers/gpio/gpio-xgene.c | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-xgene.c b/drivers/gpio/gpio-xgene.c new file mode 100644 index 000000000000..e25ba14fbb64 --- /dev/null +++ b/drivers/gpio/gpio-xgene.c @@ -0,0 +1,250 @@ +/* + * AppliedMicro X-Gene SoC GPIO Driver + * + * Copyright (c) 2014, Applied Micro Circuits Corporation + * Author: Feng Kan <fkan@apm.com>. + * + * 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. + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/spinlock.h> +#include <linux/platform_device.h> +#include <linux/gpio/driver.h> +#include <linux/types.h> +#include <linux/bitops.h> + +#define GPIO_SET_DR_OFFSET 0x0C +#define GPIO_DATA_OFFSET 0x14 +#define GPIO_BANK_STRIDE 0x0C + +#define XGENE_GPIOS_PER_BANK 16 +#define XGENE_MAX_GPIO_BANKS 3 +#define XGENE_MAX_GPIOS (XGENE_GPIOS_PER_BANK * XGENE_MAX_GPIO_BANKS) + +#define GPIO_BIT_OFFSET(x) (x % XGENE_GPIOS_PER_BANK) +#define GPIO_BANK_OFFSET(x) ((x / XGENE_GPIOS_PER_BANK) * GPIO_BANK_STRIDE) + +struct xgene_gpio; + +struct xgene_gpio { + struct gpio_chip chip; + void __iomem *base; + spinlock_t lock; +#ifdef CONFIG_PM + u32 set_dr_val[XGENE_MAX_GPIO_BANKS]; +#endif +}; + +static inline struct xgene_gpio *to_xgene_gpio(struct gpio_chip *chip) +{ + return container_of(chip, struct xgene_gpio, chip); +} + +static int xgene_gpio_get(struct gpio_chip *gc, unsigned int offset) +{ + struct xgene_gpio *chip = to_xgene_gpio(gc); + unsigned long bank_offset; + u32 bit_offset; + + bank_offset = GPIO_DATA_OFFSET + GPIO_BANK_OFFSET(offset); + bit_offset = GPIO_BIT_OFFSET(offset); + return !!(ioread32(chip->base + bank_offset) & BIT(bit_offset)); +} + +static void __xgene_gpio_set(struct gpio_chip *gc, unsigned int offset, int val) +{ + struct xgene_gpio *chip = to_xgene_gpio(gc); + unsigned long bank_offset; + u32 setval, bit_offset; + + bank_offset = GPIO_SET_DR_OFFSET + GPIO_BANK_OFFSET(offset); + bit_offset = GPIO_BIT_OFFSET(offset) + XGENE_GPIOS_PER_BANK; + + setval = ioread32(chip->base + bank_offset); + if (val) + setval |= BIT(bit_offset); + else + setval &= ~BIT(bit_offset); + iowrite32(setval, chip->base + bank_offset); +} + +static void xgene_gpio_set(struct gpio_chip *gc, unsigned int offset, int val) +{ + struct xgene_gpio *chip = to_xgene_gpio(gc); + unsigned long flags; + + spin_lock_irqsave(&chip->lock, flags); + __xgene_gpio_set(gc, offset, val); + spin_unlock_irqrestore(&chip->lock, flags); +} + +static int xgene_gpio_dir_in(struct gpio_chip *gc, unsigned int offset) +{ + struct xgene_gpio *chip = to_xgene_gpio(gc); + unsigned long flags, bank_offset; + u32 dirval, bit_offset; + + bank_offset = GPIO_SET_DR_OFFSET + GPIO_BANK_OFFSET(offset); + bit_offset = GPIO_BIT_OFFSET(offset); + + spin_lock_irqsave(&chip->lock, flags); + + dirval = ioread32(chip->base + bank_offset); + dirval |= BIT(bit_offset); + iowrite32(dirval, chip->base + bank_offset); + + spin_unlock_irqrestore(&chip->lock, flags); + + return 0; +} + +static int xgene_gpio_dir_out(struct gpio_chip *gc, + unsigned int offset, int val) +{ + struct xgene_gpio *chip = to_xgene_gpio(gc); + unsigned long flags, bank_offset; + u32 dirval, bit_offset; + + bank_offset = GPIO_SET_DR_OFFSET + GPIO_BANK_OFFSET(offset); + bit_offset = GPIO_BIT_OFFSET(offset); + + spin_lock_irqsave(&chip->lock, flags); + + dirval = ioread32(chip->base + bank_offset); + dirval &= ~BIT(bit_offset); + iowrite32(dirval, chip->base + bank_offset); + __xgene_gpio_set(gc, offset, val); + + spin_unlock_irqrestore(&chip->lock, flags); + + return 0; +} + +#ifdef CONFIG_PM +static int xgene_gpio_suspend(struct device *dev) +{ + struct xgene_gpio *gpio = dev_get_drvdata(dev); + unsigned long bank_offset; + unsigned int bank; + + for (bank = 0; bank < XGENE_MAX_GPIO_BANKS; bank++) { + bank_offset = GPIO_SET_DR_OFFSET + bank * GPIO_BANK_STRIDE; + gpio->set_dr_val[bank] = ioread32(gpio->base + bank_offset); + } + return 0; +} + +static int xgene_gpio_resume(struct device *dev) +{ + struct xgene_gpio *gpio = dev_get_drvdata(dev); + unsigned long bank_offset; + unsigned int bank; + + for (bank = 0; bank < XGENE_MAX_GPIO_BANKS; bank++) { + bank_offset = GPIO_SET_DR_OFFSET + bank * GPIO_BANK_STRIDE; + iowrite32(gpio->set_dr_val[bank], gpio->base + bank_offset); + } + return 0; +} + +static SIMPLE_DEV_PM_OPS(xgene_gpio_pm, xgene_gpio_suspend, xgene_gpio_resume); +#define XGENE_GPIO_PM_OPS (&xgene_gpio_pm) +#else +#define XGENE_GPIO_PM_OPS NULL +#endif + +static int xgene_gpio_probe(struct platform_device *pdev) +{ + struct resource *res; + struct xgene_gpio *gpio; + int err = 0; + + gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL); + if (!gpio) { + err = -ENOMEM; + goto err; + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + gpio->base = devm_ioremap_nocache(&pdev->dev, res->start, + resource_size(res)); + if (IS_ERR(gpio->base)) { + err = PTR_ERR(gpio->base); + goto err; + } + + gpio->chip.ngpio = XGENE_MAX_GPIOS; + + gpio->chip.dev = &pdev->dev; + gpio->chip.direction_input = xgene_gpio_dir_in; + gpio->chip.direction_output = xgene_gpio_dir_out; + gpio->chip.get = xgene_gpio_get; + gpio->chip.set = xgene_gpio_set; + gpio->chip.label = dev_name(&pdev->dev); + gpio->chip.base = -1; + + platform_set_drvdata(pdev, gpio); + + err = gpiochip_add(&gpio->chip); + if (err) { + dev_err(&pdev->dev, + "failed to register gpiochip.\n"); + goto err; + } + + dev_info(&pdev->dev, "X-Gene GPIO driver registered.\n"); + return 0; +err: + dev_err(&pdev->dev, "X-Gene GPIO driver registration failed.\n"); + return err; +} + +static int xgene_gpio_remove(struct platform_device *pdev) +{ + struct xgene_gpio *gpio = platform_get_drvdata(pdev); + int ret = 0; + + ret = gpiochip_remove(&gpio->chip); + if (ret) + dev_err(&pdev->dev, "unable to remove gpio_chip.\n"); + return ret; +} + +#ifdef CONFIG_OF +static const struct of_device_id xgene_gpio_of_match[] = { + { .compatible = "apm,xgene-gpio", }, + {}, +}; +MODULE_DEVICE_TABLE(of, xgene_gpio_of_match); +#endif + +static struct platform_driver xgene_gpio_driver = { + .driver = { + .name = "xgene-gpio", + .owner = THIS_MODULE, + .of_match_table = xgene_gpio_of_match, + .pm = XGENE_GPIO_PM_OPS, + }, + .probe = xgene_gpio_probe, + .remove = xgene_gpio_remove, +}; + +module_platform_driver(xgene_gpio_driver); + +MODULE_AUTHOR("Feng Kan <fkan@apm.com>"); +MODULE_DESCRIPTION("APM X-Gene GPIO driver"); +MODULE_LICENSE("GPL"); |