diff options
Diffstat (limited to 'drivers/gpio/gpio-pxa.c')
| -rw-r--r-- | drivers/gpio/gpio-pxa.c | 336 | 
1 files changed, 336 insertions, 0 deletions
| diff --git a/drivers/gpio/gpio-pxa.c b/drivers/gpio/gpio-pxa.c new file mode 100644 index 000000000000..5d6a86bfc68d --- /dev/null +++ b/drivers/gpio/gpio-pxa.c @@ -0,0 +1,336 @@ +/* + *  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> + +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 = (void __iomem *)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, +}; | 
