diff options
Diffstat (limited to 'drivers/gpio/gpio-zx.c')
| -rw-r--r-- | drivers/gpio/gpio-zx.c | 324 |
1 files changed, 324 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-zx.c b/drivers/gpio/gpio-zx.c new file mode 100644 index 000000000000..12ee1969298c --- /dev/null +++ b/drivers/gpio/gpio-zx.c @@ -0,0 +1,324 @@ +/* + * Copyright (C) 2015 Linaro Ltd. + * + * 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/bitops.h> +#include <linux/device.h> +#include <linux/errno.h> +#include <linux/gpio/driver.h> +#include <linux/irqchip/chained_irq.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/pinctrl/consumer.h> +#include <linux/platform_device.h> +#include <linux/pm.h> +#include <linux/slab.h> +#include <linux/spinlock.h> + +#define ZX_GPIO_DIR 0x00 +#define ZX_GPIO_IVE 0x04 +#define ZX_GPIO_IV 0x08 +#define ZX_GPIO_IEP 0x0C +#define ZX_GPIO_IEN 0x10 +#define ZX_GPIO_DI 0x14 +#define ZX_GPIO_DO1 0x18 +#define ZX_GPIO_DO0 0x1C +#define ZX_GPIO_DO 0x20 + +#define ZX_GPIO_IM 0x28 +#define ZX_GPIO_IE 0x2C + +#define ZX_GPIO_MIS 0x30 +#define ZX_GPIO_IC 0x34 + +#define ZX_GPIO_NR 16 + +struct zx_gpio { + spinlock_t lock; + + void __iomem *base; + struct gpio_chip gc; + bool uses_pinctrl; +}; + +static inline struct zx_gpio *to_zx(struct gpio_chip *gc) +{ + return container_of(gc, struct zx_gpio, gc); +} + +static int zx_gpio_request(struct gpio_chip *gc, unsigned offset) +{ + struct zx_gpio *chip = to_zx(gc); + int gpio = gc->base + offset; + + if (chip->uses_pinctrl) + return pinctrl_request_gpio(gpio); + return 0; +} + +static void zx_gpio_free(struct gpio_chip *gc, unsigned offset) +{ + struct zx_gpio *chip = to_zx(gc); + int gpio = gc->base + offset; + + if (chip->uses_pinctrl) + pinctrl_free_gpio(gpio); +} + +static int zx_direction_input(struct gpio_chip *gc, unsigned offset) +{ + struct zx_gpio *chip = to_zx(gc); + unsigned long flags; + u16 gpiodir; + + if (offset >= gc->ngpio) + return -EINVAL; + + spin_lock_irqsave(&chip->lock, flags); + gpiodir = readw_relaxed(chip->base + ZX_GPIO_DIR); + gpiodir &= ~BIT(offset); + writew_relaxed(gpiodir, chip->base + ZX_GPIO_DIR); + spin_unlock_irqrestore(&chip->lock, flags); + + return 0; +} + +static int zx_direction_output(struct gpio_chip *gc, unsigned offset, + int value) +{ + struct zx_gpio *chip = to_zx(gc); + unsigned long flags; + u16 gpiodir; + + if (offset >= gc->ngpio) + return -EINVAL; + + spin_lock_irqsave(&chip->lock, flags); + gpiodir = readw_relaxed(chip->base + ZX_GPIO_DIR); + gpiodir |= BIT(offset); + writew_relaxed(gpiodir, chip->base + ZX_GPIO_DIR); + + if (value) + writew_relaxed(BIT(offset), chip->base + ZX_GPIO_DO1); + else + writew_relaxed(BIT(offset), chip->base + ZX_GPIO_DO0); + spin_unlock_irqrestore(&chip->lock, flags); + + return 0; +} + +static int zx_get_value(struct gpio_chip *gc, unsigned offset) +{ + struct zx_gpio *chip = to_zx(gc); + + return !!(readw_relaxed(chip->base + ZX_GPIO_DI) & BIT(offset)); +} + +static void zx_set_value(struct gpio_chip *gc, unsigned offset, int value) +{ + struct zx_gpio *chip = to_zx(gc); + + if (value) + writew_relaxed(BIT(offset), chip->base + ZX_GPIO_DO1); + else + writew_relaxed(BIT(offset), chip->base + ZX_GPIO_DO0); +} + +static int zx_irq_type(struct irq_data *d, unsigned trigger) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct zx_gpio *chip = to_zx(gc); + int offset = irqd_to_hwirq(d); + unsigned long flags; + u16 gpiois, gpioi_epos, gpioi_eneg, gpioiev; + u16 bit = BIT(offset); + + if (offset < 0 || offset >= ZX_GPIO_NR) + return -EINVAL; + + spin_lock_irqsave(&chip->lock, flags); + + gpioiev = readw_relaxed(chip->base + ZX_GPIO_IV); + gpiois = readw_relaxed(chip->base + ZX_GPIO_IVE); + gpioi_epos = readw_relaxed(chip->base + ZX_GPIO_IEP); + gpioi_eneg = readw_relaxed(chip->base + ZX_GPIO_IEN); + + if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) { + gpiois |= bit; + if (trigger & IRQ_TYPE_LEVEL_HIGH) + gpioiev |= bit; + else + gpioiev &= ~bit; + } else + gpiois &= ~bit; + + if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) { + gpioi_epos |= bit; + gpioi_eneg |= bit; + } else { + if (trigger & IRQ_TYPE_EDGE_RISING) { + gpioi_epos |= bit; + gpioi_eneg &= ~bit; + } else if (trigger & IRQ_TYPE_EDGE_FALLING) { + gpioi_eneg |= bit; + gpioi_epos &= ~bit; + } + } + + writew_relaxed(gpiois, chip->base + ZX_GPIO_IVE); + writew_relaxed(gpioi_epos, chip->base + ZX_GPIO_IEP); + writew_relaxed(gpioi_eneg, chip->base + ZX_GPIO_IEN); + writew_relaxed(gpioiev, chip->base + ZX_GPIO_IV); + spin_unlock_irqrestore(&chip->lock, flags); + + return 0; +} + +static void zx_irq_handler(unsigned irq, struct irq_desc *desc) +{ + unsigned long pending; + int offset; + struct gpio_chip *gc = irq_desc_get_handler_data(desc); + struct zx_gpio *chip = to_zx(gc); + struct irq_chip *irqchip = irq_desc_get_chip(desc); + + chained_irq_enter(irqchip, desc); + + pending = readw_relaxed(chip->base + ZX_GPIO_MIS); + writew_relaxed(pending, chip->base + ZX_GPIO_IC); + if (pending) { + for_each_set_bit(offset, &pending, ZX_GPIO_NR) + generic_handle_irq(irq_find_mapping(gc->irqdomain, + offset)); + } + + chained_irq_exit(irqchip, desc); +} + +static void zx_irq_mask(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct zx_gpio *chip = to_zx(gc); + u16 mask = BIT(irqd_to_hwirq(d) % ZX_GPIO_NR); + u16 gpioie; + + spin_lock(&chip->lock); + gpioie = readw_relaxed(chip->base + ZX_GPIO_IM) | mask; + writew_relaxed(gpioie, chip->base + ZX_GPIO_IM); + gpioie = readw_relaxed(chip->base + ZX_GPIO_IE) & ~mask; + writew_relaxed(gpioie, chip->base + ZX_GPIO_IE); + spin_unlock(&chip->lock); +} + +static void zx_irq_unmask(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct zx_gpio *chip = to_zx(gc); + u16 mask = BIT(irqd_to_hwirq(d) % ZX_GPIO_NR); + u16 gpioie; + + spin_lock(&chip->lock); + gpioie = readw_relaxed(chip->base + ZX_GPIO_IM) & ~mask; + writew_relaxed(gpioie, chip->base + ZX_GPIO_IM); + gpioie = readw_relaxed(chip->base + ZX_GPIO_IE) | mask; + writew_relaxed(gpioie, chip->base + ZX_GPIO_IE); + spin_unlock(&chip->lock); +} + +static struct irq_chip zx_irqchip = { + .name = "zx-gpio", + .irq_mask = zx_irq_mask, + .irq_unmask = zx_irq_unmask, + .irq_set_type = zx_irq_type, +}; + +static int zx_gpio_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct zx_gpio *chip; + struct resource *res; + int irq, id, ret; + + chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL); + if (!chip) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + chip->base = devm_ioremap_resource(dev, res); + if (IS_ERR(chip->base)) + return PTR_ERR(chip->base); + + spin_lock_init(&chip->lock); + if (of_property_read_bool(dev->of_node, "gpio-ranges")) + chip->uses_pinctrl = true; + + id = of_alias_get_id(dev->of_node, "gpio"); + chip->gc.request = zx_gpio_request; + chip->gc.free = zx_gpio_free; + chip->gc.direction_input = zx_direction_input; + chip->gc.direction_output = zx_direction_output; + chip->gc.get = zx_get_value; + chip->gc.set = zx_set_value; + chip->gc.base = ZX_GPIO_NR * id; + chip->gc.ngpio = ZX_GPIO_NR; + chip->gc.label = dev_name(dev); + chip->gc.dev = dev; + chip->gc.owner = THIS_MODULE; + + ret = gpiochip_add(&chip->gc); + if (ret) + return ret; + + /* + * irq_chip support + */ + writew_relaxed(0xffff, chip->base + ZX_GPIO_IM); + writew_relaxed(0, chip->base + ZX_GPIO_IE); + irq = platform_get_irq(pdev, 0); + if (irq < 0) { + dev_err(dev, "invalid IRQ\n"); + gpiochip_remove(&chip->gc); + return -ENODEV; + } + + ret = gpiochip_irqchip_add(&chip->gc, &zx_irqchip, + 0, handle_simple_irq, + IRQ_TYPE_NONE); + if (ret) { + dev_err(dev, "could not add irqchip\n"); + gpiochip_remove(&chip->gc); + return ret; + } + gpiochip_set_chained_irqchip(&chip->gc, &zx_irqchip, + irq, zx_irq_handler); + + platform_set_drvdata(pdev, chip); + dev_info(dev, "ZX GPIO chip registered\n"); + + return 0; +} + +static const struct of_device_id zx_gpio_match[] = { + { + .compatible = "zte,zx296702-gpio", + }, + { }, +}; +MODULE_DEVICE_TABLE(of, zx_gpio_match); + +static struct platform_driver zx_gpio_driver = { + .probe = zx_gpio_probe, + .driver = { + .name = "zx_gpio", + .of_match_table = of_match_ptr(zx_gpio_match), + }, +}; + +module_platform_driver(zx_gpio_driver) + +MODULE_AUTHOR("Jun Nie <[email protected]>"); +MODULE_DESCRIPTION("ZTE ZX296702 GPIO driver"); +MODULE_LICENSE("GPL"); |