--- /dev/null
+/*
+ * 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 <jun.nie@linaro.org>");
+MODULE_DESCRIPTION("ZTE ZX296702 GPIO driver");
+MODULE_LICENSE("GPL");
projects / GitHub / MotorolaMobilityLLC / kernel-slsi.git / commitdiff