OpenWrt – Rev 1
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From 69fdd2c4f937796b934e89c33acde9d082e27bfd Mon Sep 17 00:00:00 2001
From: John Crispin <blogic@openwrt.org>
Date: Mon, 4 Aug 2014 20:36:29 +0200
Subject: [PATCH 27/53] GPIO: MIPS: ralink: add gpio driver for ralink SoC
Add gpio driver for Ralink SoC. This driver makes the gpio core on
RT2880, RT305x, rt3352, rt3662, rt3883, rt5350 and mt7620 work.
Signed-off-by: John Crispin <blogic@openwrt.org>
Cc: linux-mips@linux-mips.org
Cc: linux-gpio@vger.kernel.org
---
arch/mips/include/asm/mach-ralink/gpio.h | 24 ++
drivers/gpio/Kconfig | 6 +
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-ralink.c | 355 ++++++++++++++++++++++++++++++
4 files changed, 386 insertions(+)
create mode 100644 arch/mips/include/asm/mach-ralink/gpio.h
create mode 100644 drivers/gpio/gpio-ralink.c
--- /dev/null
+++ b/arch/mips/include/asm/mach-ralink/gpio.h
@@ -0,0 +1,24 @@
+/*
+ * Ralink SoC GPIO API support
+ *
+ * Copyright (C) 2008-2009 Gabor Juhos <juhosg@openwrt.org>
+ * Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
+ *
+ * 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.
+ *
+ */
+
+#ifndef __ASM_MACH_RALINK_GPIO_H
+#define __ASM_MACH_RALINK_GPIO_H
+
+#define ARCH_NR_GPIOS 128
+#include <asm-generic/gpio.h>
+
+#define gpio_get_value __gpio_get_value
+#define gpio_set_value __gpio_set_value
+#define gpio_cansleep __gpio_cansleep
+#define gpio_to_irq __gpio_to_irq
+
+#endif /* __ASM_MACH_RALINK_GPIO_H */
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -398,6 +398,12 @@ config GPIO_REG
A 32-bit single register GPIO fixed in/out implementation. This
can be used to represent any register as a set of GPIO signals.
+config GPIO_RALINK
+ bool "Ralink GPIO Support"
+ depends on RALINK
+ help
+ Say yes here to support the Ralink SoC GPIO device
+
config GPIO_SPEAR_SPICS
bool "ST SPEAr13xx SPI Chip Select as GPIO support"
depends on PLAT_SPEAR
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -98,6 +98,7 @@ obj-$(CONFIG_GPIO_PCI_IDIO_16) += gpio-p
obj-$(CONFIG_GPIO_PISOSR) += gpio-pisosr.o
obj-$(CONFIG_GPIO_PL061) += gpio-pl061.o
obj-$(CONFIG_GPIO_PXA) += gpio-pxa.o
+obj-$(CONFIG_GPIO_RALINK) += gpio-ralink.o
obj-$(CONFIG_GPIO_RC5T583) += gpio-rc5t583.o
obj-$(CONFIG_GPIO_RDC321X) += gpio-rdc321x.o
obj-$(CONFIG_GPIO_RCAR) += gpio-rcar.o
--- /dev/null
+++ b/drivers/gpio/gpio-ralink.c
@@ -0,0 +1,355 @@
+/*
+ * 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.
+ *
+ * Copyright (C) 2009-2011 Gabor Juhos <juhosg@openwrt.org>
+ * Copyright (C) 2013 John Crispin <blogic@openwrt.org>
+ */
+
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/gpio.h>
+#include <linux/spinlock.h>
+#include <linux/platform_device.h>
+#include <linux/of_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/interrupt.h>
+
+enum ralink_gpio_reg {
+ GPIO_REG_INT = 0,
+ GPIO_REG_EDGE,
+ GPIO_REG_RENA,
+ GPIO_REG_FENA,
+ GPIO_REG_DATA,
+ GPIO_REG_DIR,
+ GPIO_REG_POL,
+ GPIO_REG_SET,
+ GPIO_REG_RESET,
+ GPIO_REG_TOGGLE,
+ GPIO_REG_MAX
+};
+
+struct ralink_gpio_chip {
+ struct gpio_chip chip;
+ u8 regs[GPIO_REG_MAX];
+
+ spinlock_t lock;
+ void __iomem *membase;
+ struct irq_domain *domain;
+ int irq;
+
+ u32 rising;
+ u32 falling;
+};
+
+#define MAP_MAX 4
+static struct irq_domain *irq_map[MAP_MAX];
+static int irq_map_count;
+static atomic_t irq_refcount = ATOMIC_INIT(0);
+
+static inline struct ralink_gpio_chip *to_ralink_gpio(struct gpio_chip *chip)
+{
+ struct ralink_gpio_chip *rg;
+
+ rg = container_of(chip, struct ralink_gpio_chip, chip);
+
+ return rg;
+}
+
+static inline void rt_gpio_w32(struct ralink_gpio_chip *rg, u8 reg, u32 val)
+{
+ iowrite32(val, rg->membase + rg->regs[reg]);
+}
+
+static inline u32 rt_gpio_r32(struct ralink_gpio_chip *rg, u8 reg)
+{
+ return ioread32(rg->membase + rg->regs[reg]);
+}
+
+static void ralink_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+ struct ralink_gpio_chip *rg = to_ralink_gpio(chip);
+
+ rt_gpio_w32(rg, (value) ? GPIO_REG_SET : GPIO_REG_RESET, BIT(offset));
+}
+
+static int ralink_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+ struct ralink_gpio_chip *rg = to_ralink_gpio(chip);
+
+ return !!(rt_gpio_r32(rg, GPIO_REG_DATA) & BIT(offset));
+}
+
+static int ralink_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+ struct ralink_gpio_chip *rg = to_ralink_gpio(chip);
+ unsigned long flags;
+ u32 t;
+
+ spin_lock_irqsave(&rg->lock, flags);
+ t = rt_gpio_r32(rg, GPIO_REG_DIR);
+ t &= ~BIT(offset);
+ rt_gpio_w32(rg, GPIO_REG_DIR, t);
+ spin_unlock_irqrestore(&rg->lock, flags);
+
+ return 0;
+}
+
+static int ralink_gpio_direction_output(struct gpio_chip *chip,
+ unsigned offset, int value)
+{
+ struct ralink_gpio_chip *rg = to_ralink_gpio(chip);
+ unsigned long flags;
+ u32 t;
+
+ spin_lock_irqsave(&rg->lock, flags);
+ ralink_gpio_set(chip, offset, value);
+ t = rt_gpio_r32(rg, GPIO_REG_DIR);
+ t |= BIT(offset);
+ rt_gpio_w32(rg, GPIO_REG_DIR, t);
+ spin_unlock_irqrestore(&rg->lock, flags);
+
+ return 0;
+}
+
+static int ralink_gpio_to_irq(struct gpio_chip *chip, unsigned pin)
+{
+ struct ralink_gpio_chip *rg = to_ralink_gpio(chip);
+
+ if (rg->irq < 1)
+ return -1;
+
+ return irq_create_mapping(rg->domain, pin);
+}
+
+static void ralink_gpio_irq_handler(struct irq_desc *desc)
+{
+ int i;
+
+ for (i = 0; i < irq_map_count; i++) {
+ struct irq_domain *domain = irq_map[i];
+ struct ralink_gpio_chip *rg;
+ unsigned long pending;
+ int bit;
+
+ rg = (struct ralink_gpio_chip *) domain->host_data;
+ pending = rt_gpio_r32(rg, GPIO_REG_INT);
+
+ for_each_set_bit(bit, &pending, rg->chip.ngpio) {
+ u32 map = irq_find_mapping(domain, bit);
+ generic_handle_irq(map);
+ rt_gpio_w32(rg, GPIO_REG_INT, BIT(bit));
+ }
+ }
+}
+
+static void ralink_gpio_irq_unmask(struct irq_data *d)
+{
+ struct ralink_gpio_chip *rg;
+ unsigned long flags;
+ u32 rise, fall;
+
+ rg = (struct ralink_gpio_chip *) d->domain->host_data;
+ rise = rt_gpio_r32(rg, GPIO_REG_RENA);
+ fall = rt_gpio_r32(rg, GPIO_REG_FENA);
+
+ spin_lock_irqsave(&rg->lock, flags);
+ rt_gpio_w32(rg, GPIO_REG_RENA, rise | (BIT(d->hwirq) & rg->rising));
+ rt_gpio_w32(rg, GPIO_REG_FENA, fall | (BIT(d->hwirq) & rg->falling));
+ spin_unlock_irqrestore(&rg->lock, flags);
+}
+
+static void ralink_gpio_irq_mask(struct irq_data *d)
+{
+ struct ralink_gpio_chip *rg;
+ unsigned long flags;
+ u32 rise, fall;
+
+ rg = (struct ralink_gpio_chip *) d->domain->host_data;
+ rise = rt_gpio_r32(rg, GPIO_REG_RENA);
+ fall = rt_gpio_r32(rg, GPIO_REG_FENA);
+
+ spin_lock_irqsave(&rg->lock, flags);
+ rt_gpio_w32(rg, GPIO_REG_FENA, fall & ~BIT(d->hwirq));
+ rt_gpio_w32(rg, GPIO_REG_RENA, rise & ~BIT(d->hwirq));
+ spin_unlock_irqrestore(&rg->lock, flags);
+}
+
+static int ralink_gpio_irq_type(struct irq_data *d, unsigned int type)
+{
+ struct ralink_gpio_chip *rg;
+ u32 mask = BIT(d->hwirq);
+
+ rg = (struct ralink_gpio_chip *) d->domain->host_data;
+
+ if (type == IRQ_TYPE_PROBE) {
+ if ((rg->rising | rg->falling) & mask)
+ return 0;
+
+ type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING;
+ }
+
+ if (type & IRQ_TYPE_EDGE_RISING)
+ rg->rising |= mask;
+ else
+ rg->rising &= ~mask;
+
+ if (type & IRQ_TYPE_EDGE_FALLING)
+ rg->falling |= mask;
+ else
+ rg->falling &= ~mask;
+
+ return 0;
+}
+
+static struct irq_chip ralink_gpio_irq_chip = {
+ .name = "GPIO",
+ .irq_unmask = ralink_gpio_irq_unmask,
+ .irq_mask = ralink_gpio_irq_mask,
+ .irq_mask_ack = ralink_gpio_irq_mask,
+ .irq_set_type = ralink_gpio_irq_type,
+};
+
+static int gpio_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
+{
+ irq_set_chip_and_handler(irq, &ralink_gpio_irq_chip, handle_level_irq);
+ irq_set_handler_data(irq, d);
+
+ return 0;
+}
+
+static const struct irq_domain_ops irq_domain_ops = {
+ .xlate = irq_domain_xlate_onecell,
+ .map = gpio_map,
+};
+
+static void ralink_gpio_irq_init(struct device_node *np,
+ struct ralink_gpio_chip *rg)
+{
+ if (irq_map_count >= MAP_MAX)
+ return;
+
+ rg->irq = irq_of_parse_and_map(np, 0);
+ if (!rg->irq)
+ return;
+
+ rg->domain = irq_domain_add_linear(np, rg->chip.ngpio,
+ &irq_domain_ops, rg);
+ if (!rg->domain) {
+ dev_err(rg->chip.parent, "irq_domain_add_linear failed\n");
+ return;
+ }
+
+ irq_map[irq_map_count++] = rg->domain;
+
+ rt_gpio_w32(rg, GPIO_REG_RENA, 0x0);
+ rt_gpio_w32(rg, GPIO_REG_FENA, 0x0);
+
+ if (!atomic_read(&irq_refcount))
+ irq_set_chained_handler(rg->irq, ralink_gpio_irq_handler);
+ atomic_inc(&irq_refcount);
+
+ dev_info(rg->chip.parent, "registering %d irq handlers\n", rg->chip.ngpio);
+}
+
+static int ralink_gpio_request(struct gpio_chip *chip, unsigned offset)
+{
+ int gpio = chip->base + offset;
+
+ return pinctrl_request_gpio(gpio);
+}
+
+static void ralink_gpio_free(struct gpio_chip *chip, unsigned offset)
+{
+ int gpio = chip->base + offset;
+
+ pinctrl_free_gpio(gpio);
+}
+
+static int ralink_gpio_probe(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ struct ralink_gpio_chip *rg;
+ const __be32 *ngpio, *gpiobase;
+
+ if (!res) {
+ dev_err(&pdev->dev, "failed to find resource\n");
+ return -ENOMEM;
+ }
+
+ rg = devm_kzalloc(&pdev->dev,
+ sizeof(struct ralink_gpio_chip), GFP_KERNEL);
+ if (!rg)
+ return -ENOMEM;
+
+ rg->membase = devm_ioremap_resource(&pdev->dev, res);
+ if (!rg->membase) {
+ dev_err(&pdev->dev, "cannot remap I/O memory region\n");
+ return -ENOMEM;
+ }
+
+ if (of_property_read_u8_array(np, "ralink,register-map",
+ rg->regs, GPIO_REG_MAX)) {
+ dev_err(&pdev->dev, "failed to read register definition\n");
+ return -EINVAL;
+ }
+
+ ngpio = of_get_property(np, "ralink,nr-gpio", NULL);
+ if (!ngpio) {
+ dev_err(&pdev->dev, "failed to read number of pins\n");
+ return -EINVAL;
+ }
+
+ gpiobase = of_get_property(np, "ralink,gpio-base", NULL);
+ if (gpiobase)
+ rg->chip.base = be32_to_cpu(*gpiobase);
+ else
+ rg->chip.base = -1;
+
+ spin_lock_init(&rg->lock);
+
+ rg->chip.parent = &pdev->dev;
+ rg->chip.label = dev_name(&pdev->dev);
+ rg->chip.of_node = np;
+ rg->chip.ngpio = be32_to_cpu(*ngpio);
+ rg->chip.direction_input = ralink_gpio_direction_input;
+ rg->chip.direction_output = ralink_gpio_direction_output;
+ rg->chip.get = ralink_gpio_get;
+ rg->chip.set = ralink_gpio_set;
+ rg->chip.request = ralink_gpio_request;
+ rg->chip.to_irq = ralink_gpio_to_irq;
+ rg->chip.free = ralink_gpio_free;
+
+ /* set polarity to low for all lines */
+ rt_gpio_w32(rg, GPIO_REG_POL, 0);
+
+ dev_info(&pdev->dev, "registering %d gpios\n", rg->chip.ngpio);
+
+ ralink_gpio_irq_init(np, rg);
+
+ return gpiochip_add(&rg->chip);
+}
+
+static const struct of_device_id ralink_gpio_match[] = {
+ { .compatible = "ralink,rt2880-gpio" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, ralink_gpio_match);
+
+static struct platform_driver ralink_gpio_driver = {
+ .probe = ralink_gpio_probe,
+ .driver = {
+ .name = "rt2880_gpio",
+ .owner = THIS_MODULE,
+ .of_match_table = ralink_gpio_match,
+ },
+};
+
+static int __init ralink_gpio_init(void)
+{
+ return platform_driver_register(&ralink_gpio_driver);
+}
+
+subsys_initcall(ralink_gpio_init);
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