diff options
Diffstat (limited to 'drivers/gpio/gpio-timberdale.c')
| -rw-r--r-- | drivers/gpio/gpio-timberdale.c | 379 |
1 files changed, 379 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-timberdale.c b/drivers/gpio/gpio-timberdale.c new file mode 100644 index 00000000000..c593bd46bfb --- /dev/null +++ b/drivers/gpio/gpio-timberdale.c @@ -0,0 +1,379 @@ +/* + * Timberdale FPGA GPIO driver + * Copyright (c) 2009 Intel Corporation + * + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +/* Supports: + * Timberdale FPGA GPIO + */ + +#include <linux/module.h> +#include <linux/gpio.h> +#include <linux/platform_device.h> +#include <linux/irq.h> +#include <linux/io.h> +#include <linux/timb_gpio.h> +#include <linux/interrupt.h> +#include <linux/slab.h> + +#define DRIVER_NAME "timb-gpio" + +#define TGPIOVAL 0x00 +#define TGPIODIR 0x04 +#define TGPIO_IER 0x08 +#define TGPIO_ISR 0x0c +#define TGPIO_IPR 0x10 +#define TGPIO_ICR 0x14 +#define TGPIO_FLR 0x18 +#define TGPIO_LVR 0x1c +#define TGPIO_VER 0x20 +#define TGPIO_BFLR 0x24 + +struct timbgpio { + void __iomem *membase; + spinlock_t lock; /* mutual exclusion */ + struct gpio_chip gpio; + int irq_base; + unsigned long last_ier; +}; + +static int timbgpio_update_bit(struct gpio_chip *gpio, unsigned index, + unsigned offset, bool enabled) +{ + struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio); + u32 reg; + + spin_lock(&tgpio->lock); + reg = ioread32(tgpio->membase + offset); + + if (enabled) + reg |= (1 << index); + else + reg &= ~(1 << index); + + iowrite32(reg, tgpio->membase + offset); + spin_unlock(&tgpio->lock); + + return 0; +} + +static int timbgpio_gpio_direction_input(struct gpio_chip *gpio, unsigned nr) +{ + return timbgpio_update_bit(gpio, nr, TGPIODIR, true); +} + +static int timbgpio_gpio_get(struct gpio_chip *gpio, unsigned nr) +{ + struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio); + u32 value; + + value = ioread32(tgpio->membase + TGPIOVAL); + return (value & (1 << nr)) ? 1 : 0; +} + +static int timbgpio_gpio_direction_output(struct gpio_chip *gpio, + unsigned nr, int val) +{ + return timbgpio_update_bit(gpio, nr, TGPIODIR, false); +} + +static void timbgpio_gpio_set(struct gpio_chip *gpio, + unsigned nr, int val) +{ + timbgpio_update_bit(gpio, nr, TGPIOVAL, val != 0); +} + +static int timbgpio_to_irq(struct gpio_chip *gpio, unsigned offset) +{ + struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio); + + if (tgpio->irq_base <= 0) + return -EINVAL; + + return tgpio->irq_base + offset; +} + +/* + * GPIO IRQ + */ +static void timbgpio_irq_disable(struct irq_data *d) +{ + struct timbgpio *tgpio = irq_data_get_irq_chip_data(d); + int offset = d->irq - tgpio->irq_base; + unsigned long flags; + + spin_lock_irqsave(&tgpio->lock, flags); + tgpio->last_ier &= ~(1 << offset); + iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER); + spin_unlock_irqrestore(&tgpio->lock, flags); +} + +static void timbgpio_irq_enable(struct irq_data *d) +{ + struct timbgpio *tgpio = irq_data_get_irq_chip_data(d); + int offset = d->irq - tgpio->irq_base; + unsigned long flags; + + spin_lock_irqsave(&tgpio->lock, flags); + tgpio->last_ier |= 1 << offset; + iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER); + spin_unlock_irqrestore(&tgpio->lock, flags); +} + +static int timbgpio_irq_type(struct irq_data *d, unsigned trigger) +{ + struct timbgpio *tgpio = irq_data_get_irq_chip_data(d); + int offset = d->irq - tgpio->irq_base; + unsigned long flags; + u32 lvr, flr, bflr = 0; + u32 ver; + int ret = 0; + + if (offset < 0 || offset > tgpio->gpio.ngpio) + return -EINVAL; + + ver = ioread32(tgpio->membase + TGPIO_VER); + + spin_lock_irqsave(&tgpio->lock, flags); + + lvr = ioread32(tgpio->membase + TGPIO_LVR); + flr = ioread32(tgpio->membase + TGPIO_FLR); + if (ver > 2) + bflr = ioread32(tgpio->membase + TGPIO_BFLR); + + if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) { + bflr &= ~(1 << offset); + flr &= ~(1 << offset); + if (trigger & IRQ_TYPE_LEVEL_HIGH) + lvr |= 1 << offset; + else + lvr &= ~(1 << offset); + } + + if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) { + if (ver < 3) { + ret = -EINVAL; + goto out; + } + else { + flr |= 1 << offset; + bflr |= 1 << offset; + } + } else { + bflr &= ~(1 << offset); + flr |= 1 << offset; + if (trigger & IRQ_TYPE_EDGE_FALLING) + lvr &= ~(1 << offset); + else + lvr |= 1 << offset; + } + + iowrite32(lvr, tgpio->membase + TGPIO_LVR); + iowrite32(flr, tgpio->membase + TGPIO_FLR); + if (ver > 2) + iowrite32(bflr, tgpio->membase + TGPIO_BFLR); + + iowrite32(1 << offset, tgpio->membase + TGPIO_ICR); + +out: + spin_unlock_irqrestore(&tgpio->lock, flags); + return ret; +} + +static void timbgpio_irq(unsigned int irq, struct irq_desc *desc) +{ + struct timbgpio *tgpio = irq_get_handler_data(irq); + unsigned long ipr; + int offset; + + desc->irq_data.chip->irq_ack(irq_get_irq_data(irq)); + ipr = ioread32(tgpio->membase + TGPIO_IPR); + iowrite32(ipr, tgpio->membase + TGPIO_ICR); + + /* + * Some versions of the hardware trash the IER register if more than + * one interrupt is received simultaneously. + */ + iowrite32(0, tgpio->membase + TGPIO_IER); + + for_each_set_bit(offset, &ipr, tgpio->gpio.ngpio) + generic_handle_irq(timbgpio_to_irq(&tgpio->gpio, offset)); + + iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER); +} + +static struct irq_chip timbgpio_irqchip = { + .name = "GPIO", + .irq_enable = timbgpio_irq_enable, + .irq_disable = timbgpio_irq_disable, + .irq_set_type = timbgpio_irq_type, +}; + +static int __devinit timbgpio_probe(struct platform_device *pdev) +{ + int err, i; + struct gpio_chip *gc; + struct timbgpio *tgpio; + struct resource *iomem; + struct timbgpio_platform_data *pdata = pdev->dev.platform_data; + int irq = platform_get_irq(pdev, 0); + + if (!pdata || pdata->nr_pins > 32) { + err = -EINVAL; + goto err_mem; + } + + iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!iomem) { + err = -EINVAL; + goto err_mem; + } + + tgpio = kzalloc(sizeof(*tgpio), GFP_KERNEL); + if (!tgpio) { + err = -EINVAL; + goto err_mem; + } + tgpio->irq_base = pdata->irq_base; + + spin_lock_init(&tgpio->lock); + + if (!request_mem_region(iomem->start, resource_size(iomem), + DRIVER_NAME)) { + err = -EBUSY; + goto err_request; + } + + tgpio->membase = ioremap(iomem->start, resource_size(iomem)); + if (!tgpio->membase) { + err = -ENOMEM; + goto err_ioremap; + } + + gc = &tgpio->gpio; + + gc->label = dev_name(&pdev->dev); + gc->owner = THIS_MODULE; + gc->dev = &pdev->dev; + gc->direction_input = timbgpio_gpio_direction_input; + gc->get = timbgpio_gpio_get; + gc->direction_output = timbgpio_gpio_direction_output; + gc->set = timbgpio_gpio_set; + gc->to_irq = (irq >= 0 && tgpio->irq_base > 0) ? timbgpio_to_irq : NULL; + gc->dbg_show = NULL; + gc->base = pdata->gpio_base; + gc->ngpio = pdata->nr_pins; + gc->can_sleep = 0; + + err = gpiochip_add(gc); + if (err) + goto err_chipadd; + + platform_set_drvdata(pdev, tgpio); + + /* make sure to disable interrupts */ + iowrite32(0x0, tgpio->membase + TGPIO_IER); + + if (irq < 0 || tgpio->irq_base <= 0) + return 0; + + for (i = 0; i < pdata->nr_pins; i++) { + irq_set_chip_and_handler_name(tgpio->irq_base + i, + &timbgpio_irqchip, handle_simple_irq, "mux"); + irq_set_chip_data(tgpio->irq_base + i, tgpio); +#ifdef CONFIG_ARM + set_irq_flags(tgpio->irq_base + i, IRQF_VALID | IRQF_PROBE); +#endif + } + + irq_set_handler_data(irq, tgpio); + irq_set_chained_handler(irq, timbgpio_irq); + + return 0; + +err_chipadd: + iounmap(tgpio->membase); +err_ioremap: + release_mem_region(iomem->start, resource_size(iomem)); +err_request: + kfree(tgpio); +err_mem: + printk(KERN_ERR DRIVER_NAME": Failed to register GPIOs: %d\n", err); + + return err; +} + +static int __devexit timbgpio_remove(struct platform_device *pdev) +{ + int err; + struct timbgpio_platform_data *pdata = pdev->dev.platform_data; + struct timbgpio *tgpio = platform_get_drvdata(pdev); + struct resource *iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + int irq = platform_get_irq(pdev, 0); + + if (irq >= 0 && tgpio->irq_base > 0) { + int i; + for (i = 0; i < pdata->nr_pins; i++) { + irq_set_chip(tgpio->irq_base + i, NULL); + irq_set_chip_data(tgpio->irq_base + i, NULL); + } + + irq_set_handler(irq, NULL); + irq_set_handler_data(irq, NULL); + } + + err = gpiochip_remove(&tgpio->gpio); + if (err) + printk(KERN_ERR DRIVER_NAME": failed to remove gpio_chip\n"); + + iounmap(tgpio->membase); + release_mem_region(iomem->start, resource_size(iomem)); + kfree(tgpio); + + platform_set_drvdata(pdev, NULL); + + return 0; +} + +static struct platform_driver timbgpio_platform_driver = { + .driver = { + .name = DRIVER_NAME, + .owner = THIS_MODULE, + }, + .probe = timbgpio_probe, + .remove = timbgpio_remove, +}; + +/*--------------------------------------------------------------------------*/ + +static int __init timbgpio_init(void) +{ + return platform_driver_register(&timbgpio_platform_driver); +} + +static void __exit timbgpio_exit(void) +{ + platform_driver_unregister(&timbgpio_platform_driver); +} + +module_init(timbgpio_init); +module_exit(timbgpio_exit); + +MODULE_DESCRIPTION("Timberdale GPIO driver"); +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Mocean Laboratories"); +MODULE_ALIAS("platform:"DRIVER_NAME); + |