/* * 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 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 (!gpio->base) { err = -ENOMEM; goto err; } gpio->chip.ngpio = XGENE_MAX_GPIOS; spin_lock_init(&gpio->lock); 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); gpiochip_remove(&gpio->chip); return 0; } static const struct of_device_id xgene_gpio_of_match[] = { { .compatible = "apm,xgene-gpio", }, {}, }; MODULE_DEVICE_TABLE(of, xgene_gpio_of_match); static struct platform_driver xgene_gpio_driver = { .driver = { .name = "xgene-gpio", .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");