diff options
Diffstat (limited to 'drivers/gpio/gpio-pxa.c')
-rw-r--r-- | drivers/gpio/gpio-pxa.c | 338 |
1 files changed, 338 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-pxa.c b/drivers/gpio/gpio-pxa.c new file mode 100644 index 0000000..ee13771 --- /dev/null +++ b/drivers/gpio/gpio-pxa.c @@ -0,0 +1,338 @@ +/* + * linux/arch/arm/plat-pxa/gpio.c + * + * Generic PXA GPIO handling + * + * Author: Nicolas Pitre + * Created: Jun 15, 2001 + * Copyright: MontaVista Software Inc. + * + * 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/gpio.h> +#include <linux/init.h> +#include <linux/irq.h> +#include <linux/io.h> +#include <linux/syscore_ops.h> +#include <linux/slab.h> + +#include <mach/gpio-pxa.h> + +int pxa_last_gpio; + +struct pxa_gpio_chip { + struct gpio_chip chip; + void __iomem *regbase; + char label[10]; + + unsigned long irq_mask; + unsigned long irq_edge_rise; + unsigned long irq_edge_fall; + +#ifdef CONFIG_PM + unsigned long saved_gplr; + unsigned long saved_gpdr; + unsigned long saved_grer; + unsigned long saved_gfer; +#endif +}; + +static DEFINE_SPINLOCK(gpio_lock); +static struct pxa_gpio_chip *pxa_gpio_chips; + +#define for_each_gpio_chip(i, c) \ + for (i = 0, c = &pxa_gpio_chips[0]; i <= pxa_last_gpio; i += 32, c++) + +static inline void __iomem *gpio_chip_base(struct gpio_chip *c) +{ + return container_of(c, struct pxa_gpio_chip, chip)->regbase; +} + +static inline struct pxa_gpio_chip *gpio_to_pxachip(unsigned gpio) +{ + return &pxa_gpio_chips[gpio_to_bank(gpio)]; +} + +static int pxa_gpio_direction_input(struct gpio_chip *chip, unsigned offset) +{ + void __iomem *base = gpio_chip_base(chip); + uint32_t value, mask = 1 << offset; + unsigned long flags; + + spin_lock_irqsave(&gpio_lock, flags); + + value = __raw_readl(base + GPDR_OFFSET); + if (__gpio_is_inverted(chip->base + offset)) + value |= mask; + else + value &= ~mask; + __raw_writel(value, base + GPDR_OFFSET); + + spin_unlock_irqrestore(&gpio_lock, flags); + return 0; +} + +static int pxa_gpio_direction_output(struct gpio_chip *chip, + unsigned offset, int value) +{ + void __iomem *base = gpio_chip_base(chip); + uint32_t tmp, mask = 1 << offset; + unsigned long flags; + + __raw_writel(mask, base + (value ? GPSR_OFFSET : GPCR_OFFSET)); + + spin_lock_irqsave(&gpio_lock, flags); + + tmp = __raw_readl(base + GPDR_OFFSET); + if (__gpio_is_inverted(chip->base + offset)) + tmp &= ~mask; + else + tmp |= mask; + __raw_writel(tmp, base + GPDR_OFFSET); + + spin_unlock_irqrestore(&gpio_lock, flags); + return 0; +} + +static int pxa_gpio_get(struct gpio_chip *chip, unsigned offset) +{ + return __raw_readl(gpio_chip_base(chip) + GPLR_OFFSET) & (1 << offset); +} + +static void pxa_gpio_set(struct gpio_chip *chip, unsigned offset, int value) +{ + __raw_writel(1 << offset, gpio_chip_base(chip) + + (value ? GPSR_OFFSET : GPCR_OFFSET)); +} + +static int __init pxa_init_gpio_chip(int gpio_end) +{ + int i, gpio, nbanks = gpio_to_bank(gpio_end) + 1; + struct pxa_gpio_chip *chips; + + chips = kzalloc(nbanks * sizeof(struct pxa_gpio_chip), GFP_KERNEL); + if (chips == NULL) { + pr_err("%s: failed to allocate GPIO chips\n", __func__); + return -ENOMEM; + } + + for (i = 0, gpio = 0; i < nbanks; i++, gpio += 32) { + struct gpio_chip *c = &chips[i].chip; + + sprintf(chips[i].label, "gpio-%d", i); + chips[i].regbase = GPIO_BANK(i); + + c->base = gpio; + c->label = chips[i].label; + + c->direction_input = pxa_gpio_direction_input; + c->direction_output = pxa_gpio_direction_output; + c->get = pxa_gpio_get; + c->set = pxa_gpio_set; + + /* number of GPIOs on last bank may be less than 32 */ + c->ngpio = (gpio + 31 > gpio_end) ? (gpio_end - gpio + 1) : 32; + gpiochip_add(c); + } + pxa_gpio_chips = chips; + return 0; +} + +/* Update only those GRERx and GFERx edge detection register bits if those + * bits are set in c->irq_mask + */ +static inline void update_edge_detect(struct pxa_gpio_chip *c) +{ + uint32_t grer, gfer; + + grer = __raw_readl(c->regbase + GRER_OFFSET) & ~c->irq_mask; + gfer = __raw_readl(c->regbase + GFER_OFFSET) & ~c->irq_mask; + grer |= c->irq_edge_rise & c->irq_mask; + gfer |= c->irq_edge_fall & c->irq_mask; + __raw_writel(grer, c->regbase + GRER_OFFSET); + __raw_writel(gfer, c->regbase + GFER_OFFSET); +} + +static int pxa_gpio_irq_type(struct irq_data *d, unsigned int type) +{ + struct pxa_gpio_chip *c; + int gpio = irq_to_gpio(d->irq); + unsigned long gpdr, mask = GPIO_bit(gpio); + + c = gpio_to_pxachip(gpio); + + if (type == IRQ_TYPE_PROBE) { + /* Don't mess with enabled GPIOs using preconfigured edges or + * GPIOs set to alternate function or to output during probe + */ + if ((c->irq_edge_rise | c->irq_edge_fall) & GPIO_bit(gpio)) + return 0; + + if (__gpio_is_occupied(gpio)) + return 0; + + type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING; + } + + gpdr = __raw_readl(c->regbase + GPDR_OFFSET); + + if (__gpio_is_inverted(gpio)) + __raw_writel(gpdr | mask, c->regbase + GPDR_OFFSET); + else + __raw_writel(gpdr & ~mask, c->regbase + GPDR_OFFSET); + + if (type & IRQ_TYPE_EDGE_RISING) + c->irq_edge_rise |= mask; + else + c->irq_edge_rise &= ~mask; + + if (type & IRQ_TYPE_EDGE_FALLING) + c->irq_edge_fall |= mask; + else + c->irq_edge_fall &= ~mask; + + update_edge_detect(c); + + pr_debug("%s: IRQ%d (GPIO%d) - edge%s%s\n", __func__, d->irq, gpio, + ((type & IRQ_TYPE_EDGE_RISING) ? " rising" : ""), + ((type & IRQ_TYPE_EDGE_FALLING) ? " falling" : "")); + return 0; +} + +static void pxa_gpio_demux_handler(unsigned int irq, struct irq_desc *desc) +{ + struct pxa_gpio_chip *c; + int loop, gpio, gpio_base, n; + unsigned long gedr; + + do { + loop = 0; + for_each_gpio_chip(gpio, c) { + gpio_base = c->chip.base; + + gedr = __raw_readl(c->regbase + GEDR_OFFSET); + gedr = gedr & c->irq_mask; + __raw_writel(gedr, c->regbase + GEDR_OFFSET); + + n = find_first_bit(&gedr, BITS_PER_LONG); + while (n < BITS_PER_LONG) { + loop = 1; + + generic_handle_irq(gpio_to_irq(gpio_base + n)); + n = find_next_bit(&gedr, BITS_PER_LONG, n + 1); + } + } + } while (loop); +} + +static void pxa_ack_muxed_gpio(struct irq_data *d) +{ + int gpio = irq_to_gpio(d->irq); + struct pxa_gpio_chip *c = gpio_to_pxachip(gpio); + + __raw_writel(GPIO_bit(gpio), c->regbase + GEDR_OFFSET); +} + +static void pxa_mask_muxed_gpio(struct irq_data *d) +{ + int gpio = irq_to_gpio(d->irq); + struct pxa_gpio_chip *c = gpio_to_pxachip(gpio); + uint32_t grer, gfer; + + c->irq_mask &= ~GPIO_bit(gpio); + + grer = __raw_readl(c->regbase + GRER_OFFSET) & ~GPIO_bit(gpio); + gfer = __raw_readl(c->regbase + GFER_OFFSET) & ~GPIO_bit(gpio); + __raw_writel(grer, c->regbase + GRER_OFFSET); + __raw_writel(gfer, c->regbase + GFER_OFFSET); +} + +static void pxa_unmask_muxed_gpio(struct irq_data *d) +{ + int gpio = irq_to_gpio(d->irq); + struct pxa_gpio_chip *c = gpio_to_pxachip(gpio); + + c->irq_mask |= GPIO_bit(gpio); + update_edge_detect(c); +} + +static struct irq_chip pxa_muxed_gpio_chip = { + .name = "GPIO", + .irq_ack = pxa_ack_muxed_gpio, + .irq_mask = pxa_mask_muxed_gpio, + .irq_unmask = pxa_unmask_muxed_gpio, + .irq_set_type = pxa_gpio_irq_type, +}; + +void __init pxa_init_gpio(int mux_irq, int start, int end, set_wake_t fn) +{ + struct pxa_gpio_chip *c; + int gpio, irq; + + pxa_last_gpio = end; + + /* Initialize GPIO chips */ + pxa_init_gpio_chip(end); + + /* clear all GPIO edge detects */ + for_each_gpio_chip(gpio, c) { + __raw_writel(0, c->regbase + GFER_OFFSET); + __raw_writel(0, c->regbase + GRER_OFFSET); + __raw_writel(~0,c->regbase + GEDR_OFFSET); + } + + for (irq = gpio_to_irq(start); irq <= gpio_to_irq(end); irq++) { + irq_set_chip_and_handler(irq, &pxa_muxed_gpio_chip, + handle_edge_irq); + set_irq_flags(irq, IRQF_VALID | IRQF_PROBE); + } + + /* Install handler for GPIO>=2 edge detect interrupts */ + irq_set_chained_handler(mux_irq, pxa_gpio_demux_handler); + pxa_muxed_gpio_chip.irq_set_wake = fn; +} + +#ifdef CONFIG_PM +static int pxa_gpio_suspend(void) +{ + struct pxa_gpio_chip *c; + int gpio; + + for_each_gpio_chip(gpio, c) { + c->saved_gplr = __raw_readl(c->regbase + GPLR_OFFSET); + c->saved_gpdr = __raw_readl(c->regbase + GPDR_OFFSET); + c->saved_grer = __raw_readl(c->regbase + GRER_OFFSET); + c->saved_gfer = __raw_readl(c->regbase + GFER_OFFSET); + + /* Clear GPIO transition detect bits */ + __raw_writel(0xffffffff, c->regbase + GEDR_OFFSET); + } + return 0; +} + +static void pxa_gpio_resume(void) +{ + struct pxa_gpio_chip *c; + int gpio; + + for_each_gpio_chip(gpio, c) { + /* restore level with set/clear */ + __raw_writel( c->saved_gplr, c->regbase + GPSR_OFFSET); + __raw_writel(~c->saved_gplr, c->regbase + GPCR_OFFSET); + + __raw_writel(c->saved_grer, c->regbase + GRER_OFFSET); + __raw_writel(c->saved_gfer, c->regbase + GFER_OFFSET); + __raw_writel(c->saved_gpdr, c->regbase + GPDR_OFFSET); + } +} +#else +#define pxa_gpio_suspend NULL +#define pxa_gpio_resume NULL +#endif + +struct syscore_ops pxa_gpio_syscore_ops = { + .suspend = pxa_gpio_suspend, + .resume = pxa_gpio_resume, +}; |