diff options
Diffstat (limited to 'arch/arm/mach-nomadik/gpio.c')
| -rw-r--r-- | arch/arm/mach-nomadik/gpio.c | 396 |
1 files changed, 396 insertions, 0 deletions
diff --git a/arch/arm/mach-nomadik/gpio.c b/arch/arm/mach-nomadik/gpio.c new file mode 100644 index 000000000000..9a09b2791e03 --- /dev/null +++ b/arch/arm/mach-nomadik/gpio.c @@ -0,0 +1,396 @@ +/* + * Generic GPIO driver for logic cells found in the Nomadik SoC + * + * Copyright (C) 2008,2009 STMicroelectronics + * Copyright (C) 2009 Alessandro Rubini <rubini@unipv.it> + * Rewritten based on work by Prafulla WADASKAR <prafulla.wadaskar@st.com> + * + * 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/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/device.h> +#include <linux/amba/bus.h> +#include <linux/io.h> +#include <linux/gpio.h> +#include <linux/spinlock.h> +#include <linux/interrupt.h> +#include <linux/irq.h> + +#include <mach/hardware.h> +#include <mach/gpio.h> + +/* + * The GPIO module in the Nomadik family of Systems-on-Chip is an + * AMBA device, managing 32 pins and alternate functions. The logic block + * is currently only used in the Nomadik. + * + * Symbols in this file are called "nmk_gpio" for "nomadik gpio" + */ + +#define NMK_GPIO_PER_CHIP 32 +struct nmk_gpio_chip { + struct gpio_chip chip; + void __iomem *addr; + unsigned int parent_irq; + spinlock_t *lock; + /* Keep track of configured edges */ + u32 edge_rising; + u32 edge_falling; +}; + +/* Mode functions */ +int nmk_gpio_set_mode(int gpio, int gpio_mode) +{ + struct nmk_gpio_chip *nmk_chip; + unsigned long flags; + u32 afunc, bfunc, bit; + + nmk_chip = get_irq_chip_data(NOMADIK_GPIO_TO_IRQ(gpio)); + if (!nmk_chip) + return -EINVAL; + + bit = 1 << (gpio - nmk_chip->chip.base); + + spin_lock_irqsave(&nmk_chip->lock, flags); + afunc = readl(nmk_chip->addr + NMK_GPIO_AFSLA) & ~bit; + bfunc = readl(nmk_chip->addr + NMK_GPIO_AFSLB) & ~bit; + if (gpio_mode & NMK_GPIO_ALT_A) + afunc |= bit; + if (gpio_mode & NMK_GPIO_ALT_B) + bfunc |= bit; + writel(afunc, nmk_chip->addr + NMK_GPIO_AFSLA); + writel(bfunc, nmk_chip->addr + NMK_GPIO_AFSLB); + spin_unlock_irqrestore(&nmk_chip->lock, flags); + + return 0; +} +EXPORT_SYMBOL(nmk_gpio_set_mode); + +int nmk_gpio_get_mode(int gpio) +{ + struct nmk_gpio_chip *nmk_chip; + u32 afunc, bfunc, bit; + + nmk_chip = get_irq_chip_data(NOMADIK_GPIO_TO_IRQ(gpio)); + if (!nmk_chip) + return -EINVAL; + + bit = 1 << (gpio - nmk_chip->chip.base); + + afunc = readl(nmk_chip->addr + NMK_GPIO_AFSLA) & bit; + bfunc = readl(nmk_chip->addr + NMK_GPIO_AFSLB) & bit; + + return (afunc ? NMK_GPIO_ALT_A : 0) | (bfunc ? NMK_GPIO_ALT_B : 0); +} +EXPORT_SYMBOL(nmk_gpio_get_mode); + + +/* IRQ functions */ +static inline int nmk_gpio_get_bitmask(int gpio) +{ + return 1 << (gpio % 32); +} + +static void nmk_gpio_irq_ack(unsigned int irq) +{ + int gpio; + struct nmk_gpio_chip *nmk_chip; + + gpio = NOMADIK_IRQ_TO_GPIO(irq); + nmk_chip = get_irq_chip_data(irq); + if (!nmk_chip) + return; + writel(nmk_gpio_get_bitmask(gpio), nmk_chip->addr + NMK_GPIO_IC); +} + +static void nmk_gpio_irq_mask(unsigned int irq) +{ + int gpio; + struct nmk_gpio_chip *nmk_chip; + unsigned long flags; + u32 bitmask, reg; + + gpio = NOMADIK_IRQ_TO_GPIO(irq); + nmk_chip = get_irq_chip_data(irq); + bitmask = nmk_gpio_get_bitmask(gpio); + if (!nmk_chip) + return; + + /* we must individually clear the two edges */ + spin_lock_irqsave(&nmk_chip->lock, flags); + if (nmk_chip->edge_rising & bitmask) { + reg = readl(nmk_chip->addr + NMK_GPIO_RWIMSC); + reg &= ~bitmask; + writel(reg, nmk_chip->addr + NMK_GPIO_RWIMSC); + } + if (nmk_chip->edge_falling & bitmask) { + reg = readl(nmk_chip->addr + NMK_GPIO_FWIMSC); + reg &= ~bitmask; + writel(reg, nmk_chip->addr + NMK_GPIO_FWIMSC); + } + spin_unlock_irqrestore(&nmk_chip->lock, flags); +}; + +static void nmk_gpio_irq_unmask(unsigned int irq) +{ + int gpio; + struct nmk_gpio_chip *nmk_chip; + unsigned long flags; + u32 bitmask, reg; + + gpio = NOMADIK_IRQ_TO_GPIO(irq); + nmk_chip = get_irq_chip_data(irq); + bitmask = nmk_gpio_get_bitmask(gpio); + if (!nmk_chip) + return; + + /* we must individually set the two edges */ + spin_lock_irqsave(&nmk_chip->lock, flags); + if (nmk_chip->edge_rising & bitmask) { + reg = readl(nmk_chip->addr + NMK_GPIO_RWIMSC); + reg |= bitmask; + writel(reg, nmk_chip->addr + NMK_GPIO_RWIMSC); + } + if (nmk_chip->edge_falling & bitmask) { + reg = readl(nmk_chip->addr + NMK_GPIO_FWIMSC); + reg |= bitmask; + writel(reg, nmk_chip->addr + NMK_GPIO_FWIMSC); + } + spin_unlock_irqrestore(&nmk_chip->lock, flags); +} + +static int nmk_gpio_irq_set_type(unsigned int irq, unsigned int type) +{ + int gpio; + struct nmk_gpio_chip *nmk_chip; + unsigned long flags; + u32 bitmask; + + gpio = NOMADIK_IRQ_TO_GPIO(irq); + nmk_chip = get_irq_chip_data(irq); + bitmask = nmk_gpio_get_bitmask(gpio); + if (!nmk_chip) + return -EINVAL; + + if (type & IRQ_TYPE_LEVEL_HIGH) + return -EINVAL; + if (type & IRQ_TYPE_LEVEL_LOW) + return -EINVAL; + + spin_lock_irqsave(&nmk_chip->lock, flags); + + nmk_chip->edge_rising &= ~bitmask; + if (type & IRQ_TYPE_EDGE_RISING) + nmk_chip->edge_rising |= bitmask; + writel(nmk_chip->edge_rising, nmk_chip->addr + NMK_GPIO_RIMSC); + + nmk_chip->edge_falling &= ~bitmask; + if (type & IRQ_TYPE_EDGE_FALLING) + nmk_chip->edge_falling |= bitmask; + writel(nmk_chip->edge_falling, nmk_chip->addr + NMK_GPIO_FIMSC); + + spin_unlock_irqrestore(&nmk_chip->lock, flags); + + nmk_gpio_irq_unmask(irq); + + return 0; +} + +static struct irq_chip nmk_gpio_irq_chip = { + .name = "Nomadik-GPIO", + .ack = nmk_gpio_irq_ack, + .mask = nmk_gpio_irq_mask, + .unmask = nmk_gpio_irq_unmask, + .set_type = nmk_gpio_irq_set_type, +}; + +static void nmk_gpio_irq_handler(unsigned int irq, struct irq_desc *desc) +{ + struct nmk_gpio_chip *nmk_chip; + struct irq_chip *host_chip; + unsigned int gpio_irq; + u32 pending; + unsigned int first_irq; + + nmk_chip = get_irq_data(irq); + first_irq = NOMADIK_GPIO_TO_IRQ(nmk_chip->chip.base); + while ( (pending = readl(nmk_chip->addr + NMK_GPIO_IS)) ) { + gpio_irq = first_irq + __ffs(pending); + generic_handle_irq(gpio_irq); + } + if (0) {/* don't ack parent irq, as ack == disable */ + host_chip = get_irq_chip(irq); + host_chip->ack(irq); + } +} + +static int nmk_gpio_init_irq(struct nmk_gpio_chip *nmk_chip) +{ + unsigned int first_irq; + int i; + + first_irq = NOMADIK_GPIO_TO_IRQ(nmk_chip->chip.base); + for (i = first_irq; i < first_irq + NMK_GPIO_PER_CHIP; i++) { + set_irq_chip(i, &nmk_gpio_irq_chip); + set_irq_handler(i, handle_edge_irq); + set_irq_flags(i, IRQF_VALID); + set_irq_chip_data(i, nmk_chip); + } + set_irq_chained_handler(nmk_chip->parent_irq, nmk_gpio_irq_handler); + set_irq_data(nmk_chip->parent_irq, nmk_chip); + return 0; +} + +/* I/O Functions */ +static int nmk_gpio_make_input(struct gpio_chip *chip, unsigned offset) +{ + struct nmk_gpio_chip *nmk_chip = + container_of(chip, struct nmk_gpio_chip, chip); + + writel(1 << offset, nmk_chip->addr + NMK_GPIO_DIRC); + return 0; +} + +static int nmk_gpio_make_output(struct gpio_chip *chip, unsigned offset, + int val) +{ + struct nmk_gpio_chip *nmk_chip = + container_of(chip, struct nmk_gpio_chip, chip); + + writel(1 << offset, nmk_chip->addr + NMK_GPIO_DIRS); + return 0; +} + +static int nmk_gpio_get_input(struct gpio_chip *chip, unsigned offset) +{ + struct nmk_gpio_chip *nmk_chip = + container_of(chip, struct nmk_gpio_chip, chip); + u32 bit = 1 << offset; + + return (readl(nmk_chip->addr + NMK_GPIO_DAT) & bit) != 0; +} + +static void nmk_gpio_set_output(struct gpio_chip *chip, unsigned offset, + int val) +{ + struct nmk_gpio_chip *nmk_chip = + container_of(chip, struct nmk_gpio_chip, chip); + u32 bit = 1 << offset; + + if (val) + writel(bit, nmk_chip->addr + NMK_GPIO_DATS); + else + writel(bit, nmk_chip->addr + NMK_GPIO_DATC); +} + +/* This structure is replicated for each GPIO block allocated at probe time */ +static struct gpio_chip nmk_gpio_template = { + .direction_input = nmk_gpio_make_input, + .get = nmk_gpio_get_input, + .direction_output = nmk_gpio_make_output, + .set = nmk_gpio_set_output, + .ngpio = NMK_GPIO_PER_CHIP, + .can_sleep = 0, +}; + +static int __init nmk_gpio_probe(struct amba_device *dev, struct amba_id *id) +{ + struct nmk_gpio_platform_data *pdata; + struct nmk_gpio_chip *nmk_chip; + struct gpio_chip *chip; + int ret; + + pdata = dev->dev.platform_data; + ret = amba_request_regions(dev, pdata->name); + if (ret) + return ret; + + nmk_chip = kzalloc(sizeof(*nmk_chip), GFP_KERNEL); + if (!nmk_chip) { + ret = -ENOMEM; + goto out_amba; + } + /* + * The virt address in nmk_chip->addr is in the nomadik register space, + * so we can simply convert the resource address, without remapping + */ + nmk_chip->addr = io_p2v(dev->res.start); + nmk_chip->chip = nmk_gpio_template; + nmk_chip->parent_irq = pdata->parent_irq; + + chip = &nmk_chip->chip; + chip->base = pdata->first_gpio; + chip->label = pdata->name; + chip->dev = &dev->dev; + chip->owner = THIS_MODULE; + + ret = gpiochip_add(&nmk_chip->chip); + if (ret) + goto out_free; + + amba_set_drvdata(dev, nmk_chip); + + nmk_gpio_init_irq(nmk_chip); + + dev_info(&dev->dev, "Bits %i-%i at address %p\n", + nmk_chip->chip.base, nmk_chip->chip.base+31, nmk_chip->addr); + return 0; + + out_free: + kfree(nmk_chip); + out_amba: + amba_release_regions(dev); + dev_err(&dev->dev, "Failure %i for GPIO %i-%i\n", ret, + pdata->first_gpio, pdata->first_gpio+31); + return ret; +} + +static int nmk_gpio_remove(struct amba_device *dev) +{ + struct nmk_gpio_chip *nmk_chip; + + nmk_chip = amba_get_drvdata(dev); + gpiochip_remove(&nmk_chip->chip); + kfree(nmk_chip); + amba_release_regions(dev); + return 0; +} + + +/* We have 0x1f080060 and 0x1f180060, accept both using the mask */ +static struct amba_id nmk_gpio_ids[] = { + { + .id = 0x1f080060, + .mask = 0xffefffff, + }, + {0, 0}, +}; + +static struct amba_driver nmk_gpio_driver = { + .drv = { + .owner = THIS_MODULE, + .name = "gpio", + }, + .probe = nmk_gpio_probe, + .remove = nmk_gpio_remove, + .suspend = NULL, /* to be done */ + .resume = NULL, + .id_table = nmk_gpio_ids, +}; + +static int __init nmk_gpio_init(void) +{ + return amba_driver_register(&nmk_gpio_driver); +} + +arch_initcall(nmk_gpio_init); + +MODULE_AUTHOR("Prafulla WADASKAR and Alessandro Rubini"); +MODULE_DESCRIPTION("Nomadik GPIO Driver"); +MODULE_LICENSE("GPL"); + + |