diff options
Diffstat (limited to 'drivers/gpio/gpio-pl061.c')
| -rw-r--r-- | drivers/gpio/gpio-pl061.c | 392 |
1 files changed, 392 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-pl061.c b/drivers/gpio/gpio-pl061.c new file mode 100644 index 00000000..b4b5da4f --- /dev/null +++ b/drivers/gpio/gpio-pl061.c @@ -0,0 +1,392 @@ +/* + * 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/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> +#include <linux/pm.h> +#include <asm/mach/irq.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 + +#ifdef CONFIG_PM +struct pl061_context_save_regs { + u8 gpio_data; + u8 gpio_dir; + u8 gpio_is; + u8 gpio_ibe; + u8 gpio_iev; + u8 gpio_ie; +}; +#endif + +struct pl061_gpio { + /* 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 */ + + void __iomem *base; + int irq_base; + struct irq_chip_generic *irq_gc; + struct gpio_chip gc; + +#ifdef CONFIG_PM + struct pl061_context_save_regs csave_regs; +#endif +}; + +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 <= 0) + return -EINVAL; + + return chip->irq_base + offset; +} + +static int pl061_irq_type(struct irq_data *d, unsigned trigger) +{ + struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d); + struct pl061_gpio *chip = gc->private; + int offset = d->irq - chip->irq_base; + unsigned long flags; + u8 gpiois, gpioibe, gpioiev; + + if (offset < 0 || offset >= PL061_GPIO_NR) + return -EINVAL; + + raw_spin_lock_irqsave(&gc->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); + + raw_spin_unlock_irqrestore(&gc->lock, flags); + + return 0; +} + +static void pl061_irq_handler(unsigned irq, struct irq_desc *desc) +{ + unsigned long pending; + int offset; + struct pl061_gpio *chip = irq_desc_get_handler_data(desc); + struct irq_chip *irqchip = irq_desc_get_chip(desc); + + chained_irq_enter(irqchip, desc); + + pending = readb(chip->base + GPIOMIS); + writeb(pending, chip->base + GPIOIC); + if (pending) { + for_each_set_bit(offset, &pending, PL061_GPIO_NR) + generic_handle_irq(pl061_to_irq(&chip->gc, offset)); + } + + chained_irq_exit(irqchip, desc); +} + +static void __init pl061_init_gc(struct pl061_gpio *chip, int irq_base) +{ + struct irq_chip_type *ct; + + chip->irq_gc = irq_alloc_generic_chip("gpio-pl061", 1, irq_base, + chip->base, handle_simple_irq); + chip->irq_gc->private = chip; + + ct = chip->irq_gc->chip_types; + ct->chip.irq_mask = irq_gc_mask_clr_bit; + ct->chip.irq_unmask = irq_gc_mask_set_bit; + ct->chip.irq_set_type = pl061_irq_type; + ct->chip.irq_set_wake = irq_gc_set_wake; + ct->regs.mask = GPIOIE; + + irq_setup_generic_chip(chip->irq_gc, IRQ_MSK(PL061_GPIO_NR), + IRQ_GC_INIT_NESTED_LOCK, IRQ_NOREQUEST, 0); +} + +static int pl061_probe(struct amba_device *dev, const struct amba_id *id) +{ + struct pl061_platform_data *pdata; + struct pl061_gpio *chip; + int ret, irq, i; + + chip = kzalloc(sizeof(*chip), GFP_KERNEL); + if (chip == NULL) + return -ENOMEM; + + pdata = dev->dev.platform_data; + if (pdata) { + chip->gc.base = pdata->gpio_base; + chip->irq_base = pdata->irq_base; + } else if (dev->dev.of_node) { + chip->gc.base = -1; + chip->irq_base = 0; + } else { + ret = -ENODEV; + goto free_mem; + } + + 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); + + 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.ngpio = PL061_GPIO_NR; + chip->gc.label = dev_name(&dev->dev); + chip->gc.dev = &dev->dev; + chip->gc.owner = THIS_MODULE; + + ret = gpiochip_add(&chip->gc); + if (ret) + goto iounmap; + + /* + * irq_chip support + */ + + if (chip->irq_base <= 0) + return 0; + + pl061_init_gc(chip, chip->irq_base); + + 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); + irq_set_handler_data(irq, chip); + + for (i = 0; i < PL061_GPIO_NR; i++) { + if (pdata) { + if (pdata->directions & (1 << i)) + pl061_direction_output(&chip->gc, i, + pdata->values & (1 << i)); + else + pl061_direction_input(&chip->gc, i); + } + } + + amba_set_drvdata(dev, 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; +} + +#ifdef CONFIG_PM +static int pl061_suspend(struct device *dev) +{ + struct pl061_gpio *chip = dev_get_drvdata(dev); + int offset; + + chip->csave_regs.gpio_data = 0; + chip->csave_regs.gpio_dir = readb(chip->base + GPIODIR); + chip->csave_regs.gpio_is = readb(chip->base + GPIOIS); + chip->csave_regs.gpio_ibe = readb(chip->base + GPIOIBE); + chip->csave_regs.gpio_iev = readb(chip->base + GPIOIEV); + chip->csave_regs.gpio_ie = readb(chip->base + GPIOIE); + + for (offset = 0; offset < PL061_GPIO_NR; offset++) { + if (chip->csave_regs.gpio_dir & (1 << offset)) + chip->csave_regs.gpio_data |= + pl061_get_value(&chip->gc, offset) << offset; + } + + return 0; +} + +static int pl061_resume(struct device *dev) +{ + struct pl061_gpio *chip = dev_get_drvdata(dev); + int offset; + + for (offset = 0; offset < PL061_GPIO_NR; offset++) { + if (chip->csave_regs.gpio_dir & (1 << offset)) + pl061_direction_output(&chip->gc, offset, + chip->csave_regs.gpio_data & + (1 << offset)); + else + pl061_direction_input(&chip->gc, offset); + } + + writeb(chip->csave_regs.gpio_is, chip->base + GPIOIS); + writeb(chip->csave_regs.gpio_ibe, chip->base + GPIOIBE); + writeb(chip->csave_regs.gpio_iev, chip->base + GPIOIEV); + writeb(chip->csave_regs.gpio_ie, chip->base + GPIOIE); + + return 0; +} + +static const struct dev_pm_ops pl061_dev_pm_ops = { + .suspend = pl061_suspend, + .resume = pl061_resume, + .freeze = pl061_suspend, + .restore = pl061_resume, +}; +#endif + +static struct amba_id pl061_ids[] = { + { + .id = 0x00041061, + .mask = 0x000fffff, + }, + { 0, 0 }, +}; + +MODULE_DEVICE_TABLE(amba, pl061_ids); + +static struct amba_driver pl061_gpio_driver = { + .drv = { + .name = "pl061_gpio", +#ifdef CONFIG_PM + .pm = &pl061_dev_pm_ops, +#endif + }, + .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"); |