diff options
Diffstat (limited to 'drivers/gpio/gpio-pl061.c')
| -rw-r--r-- | drivers/gpio/gpio-pl061.c | 358 |
1 files changed, 358 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-pl061.c b/drivers/gpio/gpio-pl061.c new file mode 100644 index 0000000..2c5a18f --- /dev/null +++ b/drivers/gpio/gpio-pl061.c @@ -0,0 +1,358 @@ +/* + * Copyright (C) 2008, 2009 Provigent 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. + * + * Driver for the ARM PrimeCell(tm) General Purpose Input/Output (PL061) + * + * Data sheet: ARM DDI 0190B, September 2000 + */ +#include <linux/spinlock.h> +#include <linux/errno.h> +#include <linux/module.h> +#include <linux/list.h> +#include <linux/io.h> +#include <linux/ioport.h> +#include <linux/irq.h> +#include <linux/bitops.h> +#include <linux/workqueue.h> +#include <linux/gpio.h> +#include <linux/device.h> +#include <linux/amba/bus.h> +#include <linux/amba/pl061.h> +#include <linux/slab.h> + +#define GPIODIR 0x400 +#define GPIOIS 0x404 +#define GPIOIBE 0x408 +#define GPIOIEV 0x40C +#define GPIOIE 0x410 +#define GPIORIS 0x414 +#define GPIOMIS 0x418 +#define GPIOIC 0x41C + +#define PL061_GPIO_NR 8 + +struct pl061_gpio { + /* We use a list of pl061_gpio structs for each trigger IRQ in the main + * interrupts controller of the system. We need this to support systems + * in which more that one PL061s are connected to the same IRQ. The ISR + * interates through this list to find the source of the interrupt. + */ + struct list_head list; + + /* Each of the two spinlocks protects a different set of hardware + * regiters and data structurs. This decouples the code of the IRQ from + * the GPIO code. This also makes the case of a GPIO routine call from + * the IRQ code simpler. + */ + spinlock_t lock; /* GPIO registers */ + spinlock_t irq_lock; /* IRQ registers */ + + void __iomem *base; + unsigned irq_base; + struct gpio_chip gc; +}; + +static int pl061_direction_input(struct gpio_chip *gc, unsigned offset) +{ + struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc); + unsigned long flags; + unsigned char gpiodir; + + if (offset >= gc->ngpio) + return -EINVAL; + + spin_lock_irqsave(&chip->lock, flags); + gpiodir = readb(chip->base + GPIODIR); + gpiodir &= ~(1 << offset); + writeb(gpiodir, chip->base + GPIODIR); + spin_unlock_irqrestore(&chip->lock, flags); + + return 0; +} + +static int pl061_direction_output(struct gpio_chip *gc, unsigned offset, + int value) +{ + struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc); + unsigned long flags; + unsigned char gpiodir; + + if (offset >= gc->ngpio) + return -EINVAL; + + spin_lock_irqsave(&chip->lock, flags); + writeb(!!value << offset, chip->base + (1 << (offset + 2))); + gpiodir = readb(chip->base + GPIODIR); + gpiodir |= 1 << offset; + writeb(gpiodir, chip->base + GPIODIR); + + /* + * gpio value is set again, because pl061 doesn't allow to set value of + * a gpio pin before configuring it in OUT mode. + */ + writeb(!!value << offset, chip->base + (1 << (offset + 2))); + spin_unlock_irqrestore(&chip->lock, flags); + + return 0; +} + +static int pl061_get_value(struct gpio_chip *gc, unsigned offset) +{ + struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc); + + return !!readb(chip->base + (1 << (offset + 2))); +} + +static void pl061_set_value(struct gpio_chip *gc, unsigned offset, int value) +{ + struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc); + + writeb(!!value << offset, chip->base + (1 << (offset + 2))); +} + +static int pl061_to_irq(struct gpio_chip *gc, unsigned offset) +{ + struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc); + + if (chip->irq_base == (unsigned) -1) + return -EINVAL; + + return chip->irq_base + offset; +} + +/* + * PL061 GPIO IRQ + */ +static void pl061_irq_disable(struct irq_data *d) +{ + struct pl061_gpio *chip = irq_data_get_irq_chip_data(d); + int offset = d->irq - chip->irq_base; + unsigned long flags; + u8 gpioie; + + spin_lock_irqsave(&chip->irq_lock, flags); + gpioie = readb(chip->base + GPIOIE); + gpioie &= ~(1 << offset); + writeb(gpioie, chip->base + GPIOIE); + spin_unlock_irqrestore(&chip->irq_lock, flags); +} + +static void pl061_irq_enable(struct irq_data *d) +{ + struct pl061_gpio *chip = irq_data_get_irq_chip_data(d); + int offset = d->irq - chip->irq_base; + unsigned long flags; + u8 gpioie; + + spin_lock_irqsave(&chip->irq_lock, flags); + gpioie = readb(chip->base + GPIOIE); + gpioie |= 1 << offset; + writeb(gpioie, chip->base + GPIOIE); + spin_unlock_irqrestore(&chip->irq_lock, flags); +} + +static int pl061_irq_type(struct irq_data *d, unsigned trigger) +{ + struct pl061_gpio *chip = irq_data_get_irq_chip_data(d); + int offset = d->irq - chip->irq_base; + unsigned long flags; + u8 gpiois, gpioibe, gpioiev; + + if (offset < 0 || offset >= PL061_GPIO_NR) + return -EINVAL; + + spin_lock_irqsave(&chip->irq_lock, flags); + + gpioiev = readb(chip->base + GPIOIEV); + + gpiois = readb(chip->base + GPIOIS); + if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) { + gpiois |= 1 << offset; + if (trigger & IRQ_TYPE_LEVEL_HIGH) + gpioiev |= 1 << offset; + else + gpioiev &= ~(1 << offset); + } else + gpiois &= ~(1 << offset); + writeb(gpiois, chip->base + GPIOIS); + + gpioibe = readb(chip->base + GPIOIBE); + if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) + gpioibe |= 1 << offset; + else { + gpioibe &= ~(1 << offset); + if (trigger & IRQ_TYPE_EDGE_RISING) + gpioiev |= 1 << offset; + else if (trigger & IRQ_TYPE_EDGE_FALLING) + gpioiev &= ~(1 << offset); + } + writeb(gpioibe, chip->base + GPIOIBE); + + writeb(gpioiev, chip->base + GPIOIEV); + + spin_unlock_irqrestore(&chip->irq_lock, flags); + + return 0; +} + +static struct irq_chip pl061_irqchip = { + .name = "GPIO", + .irq_enable = pl061_irq_enable, + .irq_disable = pl061_irq_disable, + .irq_set_type = pl061_irq_type, +}; + +static void pl061_irq_handler(unsigned irq, struct irq_desc *desc) +{ + struct list_head *chip_list = irq_get_handler_data(irq); + struct list_head *ptr; + struct pl061_gpio *chip; + + desc->irq_data.chip->irq_ack(&desc->irq_data); + list_for_each(ptr, chip_list) { + unsigned long pending; + int offset; + + chip = list_entry(ptr, struct pl061_gpio, list); + pending = readb(chip->base + GPIOMIS); + writeb(pending, chip->base + GPIOIC); + + if (pending == 0) + continue; + + for_each_set_bit(offset, &pending, PL061_GPIO_NR) + generic_handle_irq(pl061_to_irq(&chip->gc, offset)); + } + desc->irq_data.chip->irq_unmask(&desc->irq_data); +} + +static int pl061_probe(struct amba_device *dev, const struct amba_id *id) +{ + struct pl061_platform_data *pdata; + struct pl061_gpio *chip; + struct list_head *chip_list; + int ret, irq, i; + static DECLARE_BITMAP(init_irq, NR_IRQS); + + pdata = dev->dev.platform_data; + if (pdata == NULL) + return -ENODEV; + + chip = kzalloc(sizeof(*chip), GFP_KERNEL); + if (chip == NULL) + return -ENOMEM; + + if (!request_mem_region(dev->res.start, + resource_size(&dev->res), "pl061")) { + ret = -EBUSY; + goto free_mem; + } + + chip->base = ioremap(dev->res.start, resource_size(&dev->res)); + if (chip->base == NULL) { + ret = -ENOMEM; + goto release_region; + } + + spin_lock_init(&chip->lock); + spin_lock_init(&chip->irq_lock); + INIT_LIST_HEAD(&chip->list); + + chip->gc.direction_input = pl061_direction_input; + chip->gc.direction_output = pl061_direction_output; + chip->gc.get = pl061_get_value; + chip->gc.set = pl061_set_value; + chip->gc.to_irq = pl061_to_irq; + chip->gc.base = pdata->gpio_base; + chip->gc.ngpio = PL061_GPIO_NR; + chip->gc.label = dev_name(&dev->dev); + chip->gc.dev = &dev->dev; + chip->gc.owner = THIS_MODULE; + + chip->irq_base = pdata->irq_base; + + ret = gpiochip_add(&chip->gc); + if (ret) + goto iounmap; + + /* + * irq_chip support + */ + + if (chip->irq_base == (unsigned) -1) + return 0; + + writeb(0, chip->base + GPIOIE); /* disable irqs */ + irq = dev->irq[0]; + if (irq < 0) { + ret = -ENODEV; + goto iounmap; + } + irq_set_chained_handler(irq, pl061_irq_handler); + if (!test_and_set_bit(irq, init_irq)) { /* list initialized? */ + chip_list = kmalloc(sizeof(*chip_list), GFP_KERNEL); + if (chip_list == NULL) { + clear_bit(irq, init_irq); + ret = -ENOMEM; + goto iounmap; + } + INIT_LIST_HEAD(chip_list); + irq_set_handler_data(irq, chip_list); + } else + chip_list = irq_get_handler_data(irq); + list_add(&chip->list, chip_list); + + for (i = 0; i < PL061_GPIO_NR; i++) { + if (pdata->directions & (1 << i)) + pl061_direction_output(&chip->gc, i, + pdata->values & (1 << i)); + else + pl061_direction_input(&chip->gc, i); + + irq_set_chip_and_handler(i + chip->irq_base, &pl061_irqchip, + handle_simple_irq); + set_irq_flags(i+chip->irq_base, IRQF_VALID); + irq_set_chip_data(i + chip->irq_base, chip); + } + + return 0; + +iounmap: + iounmap(chip->base); +release_region: + release_mem_region(dev->res.start, resource_size(&dev->res)); +free_mem: + kfree(chip); + + return ret; +} + +static struct amba_id pl061_ids[] = { + { + .id = 0x00041061, + .mask = 0x000fffff, + }, + { 0, 0 }, +}; + +static struct amba_driver pl061_gpio_driver = { + .drv = { + .name = "pl061_gpio", + }, + .id_table = pl061_ids, + .probe = pl061_probe, +}; + +static int __init pl061_gpio_init(void) +{ + return amba_driver_register(&pl061_gpio_driver); +} +subsys_initcall(pl061_gpio_init); + +MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>"); +MODULE_DESCRIPTION("PL061 GPIO driver"); +MODULE_LICENSE("GPL"); |
