 a88656553d
			
		
	
	
	a88656553d
	
	
	
		
			
			Signed-off-by: Erik Benada <erikbenada@yahoo.ca> [ nico: fix locking, additional cleanups ] Signed-off-by: Nicolas Pitre <nico@marvell.com>
		
			
				
	
	
		
			359 lines
		
	
	
	
		
			8.5 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			359 lines
		
	
	
	
		
			8.5 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * arch/arm/plat-orion/gpio.c
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|  *
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|  * Marvell Orion SoC GPIO handling.
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|  *
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|  * This file is licensed under the terms of the GNU General Public
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|  * License version 2.  This program is licensed "as is" without any
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|  * warranty of any kind, whether express or implied.
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|  */
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| 
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| #include <linux/kernel.h>
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| #include <linux/init.h>
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| #include <linux/irq.h>
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| #include <linux/module.h>
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| #include <linux/spinlock.h>
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| #include <linux/bitops.h>
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| #include <linux/io.h>
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| #include <linux/gpio.h>
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| 
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| static DEFINE_SPINLOCK(gpio_lock);
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| static unsigned long gpio_valid_input[BITS_TO_LONGS(GPIO_MAX)];
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| static unsigned long gpio_valid_output[BITS_TO_LONGS(GPIO_MAX)];
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| 
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| static inline void __set_direction(unsigned pin, int input)
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| {
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| 	u32 u;
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| 
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| 	u = readl(GPIO_IO_CONF(pin));
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| 	if (input)
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| 		u |= 1 << (pin & 31);
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| 	else
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| 		u &= ~(1 << (pin & 31));
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| 	writel(u, GPIO_IO_CONF(pin));
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| }
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| 
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| static void __set_level(unsigned pin, int high)
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| {
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| 	u32 u;
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| 
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| 	u = readl(GPIO_OUT(pin));
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| 	if (high)
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| 		u |= 1 << (pin & 31);
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| 	else
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| 		u &= ~(1 << (pin & 31));
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| 	writel(u, GPIO_OUT(pin));
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| }
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| 
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| static inline void __set_blinking(unsigned pin, int blink)
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| {
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| 	u32 u;
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| 
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| 	u = readl(GPIO_BLINK_EN(pin));
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| 	if (blink)
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| 		u |= 1 << (pin & 31);
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| 	else
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| 		u &= ~(1 << (pin & 31));
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| 	writel(u, GPIO_BLINK_EN(pin));
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| }
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| 
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| static inline int orion_gpio_is_valid(unsigned pin, int mode)
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| {
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| 	if (pin < GPIO_MAX) {
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| 		if ((mode & GPIO_INPUT_OK) && !test_bit(pin, gpio_valid_input))
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| 			goto err_out;
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| 		if ((mode & GPIO_OUTPUT_OK) && !test_bit(pin, gpio_valid_output))
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| 			goto err_out;
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| 		return true;
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| 	}
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| 
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| err_out:
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| 	pr_debug("%s: invalid GPIO %d\n", __func__, pin);
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| 	return false;
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| }
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| 
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| /*
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|  * GENERIC_GPIO primitives.
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|  */
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| static int orion_gpio_direction_input(struct gpio_chip *chip, unsigned pin)
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| {
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| 	unsigned long flags;
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| 
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| 	if (!orion_gpio_is_valid(pin, GPIO_INPUT_OK))
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| 		return -EINVAL;
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| 
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| 	spin_lock_irqsave(&gpio_lock, flags);
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| 
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| 	/* Configure GPIO direction. */
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| 	__set_direction(pin, 1);
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| 
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| 	spin_unlock_irqrestore(&gpio_lock, flags);
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| 
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| 	return 0;
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| }
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| 
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| static int orion_gpio_get_value(struct gpio_chip *chip, unsigned pin)
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| {
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| 	int val;
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| 
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| 	if (readl(GPIO_IO_CONF(pin)) & (1 << (pin & 31)))
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| 		val = readl(GPIO_DATA_IN(pin)) ^ readl(GPIO_IN_POL(pin));
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| 	else
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| 		val = readl(GPIO_OUT(pin));
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| 
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| 	return (val >> (pin & 31)) & 1;
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| }
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| 
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| static int orion_gpio_direction_output(struct gpio_chip *chip, unsigned pin,
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| 	int value)
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| {
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| 	unsigned long flags;
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| 
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| 	if (!orion_gpio_is_valid(pin, GPIO_OUTPUT_OK))
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| 		return -EINVAL;
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| 
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| 	spin_lock_irqsave(&gpio_lock, flags);
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| 
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| 	/* Disable blinking. */
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| 	__set_blinking(pin, 0);
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| 
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| 	/* Configure GPIO output value. */
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| 	__set_level(pin, value);
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| 
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| 	/* Configure GPIO direction. */
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| 	__set_direction(pin, 0);
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| 
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| 	spin_unlock_irqrestore(&gpio_lock, flags);
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| 
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| 	return 0;
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| }
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| 
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| static void orion_gpio_set_value(struct gpio_chip *chip, unsigned pin,
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| 	int value)
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| {
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| 	unsigned long flags;
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| 
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| 	spin_lock_irqsave(&gpio_lock, flags);
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| 
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| 	/* Configure GPIO output value. */
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| 	__set_level(pin, value);
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| 
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| 	spin_unlock_irqrestore(&gpio_lock, flags);
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| }
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| 
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| static int orion_gpio_request(struct gpio_chip *chip, unsigned pin)
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| {
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| 	if (orion_gpio_is_valid(pin, GPIO_INPUT_OK) ||
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| 	    orion_gpio_is_valid(pin, GPIO_OUTPUT_OK))
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| 		return 0;
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| 	return -EINVAL;
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| }
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| 
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| static struct gpio_chip orion_gpiochip = {
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| 	.label			= "orion_gpio",
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| 	.direction_input	= orion_gpio_direction_input,
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| 	.get			= orion_gpio_get_value,
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| 	.direction_output	= orion_gpio_direction_output,
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| 	.set			= orion_gpio_set_value,
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| 	.request		= orion_gpio_request,
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| 	.base			= 0,
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| 	.ngpio			= GPIO_MAX,
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| 	.can_sleep		= 0,
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| };
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| 
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| void __init orion_gpio_init(void)
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| {
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| 	gpiochip_add(&orion_gpiochip);
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| }
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| 
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| /*
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|  * Orion-specific GPIO API extensions.
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|  */
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| void __init orion_gpio_set_unused(unsigned pin)
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| {
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| 	/* Configure as output, drive low. */
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| 	__set_level(pin, 0);
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| 	__set_direction(pin, 0);
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| }
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| 
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| void __init orion_gpio_set_valid(unsigned pin, int mode)
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| {
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| 	if (mode == 1)
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| 		mode = GPIO_INPUT_OK | GPIO_OUTPUT_OK;
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| 	if (mode & GPIO_INPUT_OK)
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| 		__set_bit(pin, gpio_valid_input);
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| 	else
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| 		__clear_bit(pin, gpio_valid_input);
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| 	if (mode & GPIO_OUTPUT_OK)
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| 		__set_bit(pin, gpio_valid_output);
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| 	else
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| 		__clear_bit(pin, gpio_valid_output);
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| }
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| 
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| void orion_gpio_set_blink(unsigned pin, int blink)
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| {
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| 	unsigned long flags;
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| 
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| 	spin_lock_irqsave(&gpio_lock, flags);
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| 
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| 	/* Set output value to zero. */
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| 	__set_level(pin, 0);
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| 
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| 	/* Set blinking. */
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| 	__set_blinking(pin, blink);
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| 
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| 	spin_unlock_irqrestore(&gpio_lock, flags);
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| }
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| EXPORT_SYMBOL(orion_gpio_set_blink);
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| 
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| 
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| /*****************************************************************************
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|  * Orion GPIO IRQ
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|  *
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|  * GPIO_IN_POL register controls whether GPIO_DATA_IN will hold the same
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|  * value of the line or the opposite value.
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|  *
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|  * Level IRQ handlers: DATA_IN is used directly as cause register.
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|  *                     Interrupt are masked by LEVEL_MASK registers.
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|  * Edge IRQ handlers:  Change in DATA_IN are latched in EDGE_CAUSE.
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|  *                     Interrupt are masked by EDGE_MASK registers.
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|  * Both-edge handlers: Similar to regular Edge handlers, but also swaps
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|  *                     the polarity to catch the next line transaction.
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|  *                     This is a race condition that might not perfectly
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|  *                     work on some use cases.
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|  *
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|  * Every eight GPIO lines are grouped (OR'ed) before going up to main
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|  * cause register.
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|  *
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|  *                    EDGE  cause    mask
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|  *        data-in   /--------| |-----| |----\
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|  *     -----| |-----                         ---- to main cause reg
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|  *           X      \----------------| |----/
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|  *        polarity    LEVEL          mask
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|  *
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|  ****************************************************************************/
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| 
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| static void gpio_irq_ack(u32 irq)
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| {
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| 	int type = irq_desc[irq].status & IRQ_TYPE_SENSE_MASK;
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| 	if (type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING)) {
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| 		int pin = irq_to_gpio(irq);
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| 		writel(~(1 << (pin & 31)), GPIO_EDGE_CAUSE(pin));
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| 	}
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| }
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| 
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| static void gpio_irq_mask(u32 irq)
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| {
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| 	int pin = irq_to_gpio(irq);
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| 	int type = irq_desc[irq].status & IRQ_TYPE_SENSE_MASK;
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| 	u32 reg = (type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING)) ?
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| 		GPIO_EDGE_MASK(pin) : GPIO_LEVEL_MASK(pin);
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| 	u32 u = readl(reg);
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| 	u &= ~(1 << (pin & 31));
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| 	writel(u, reg);
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| }
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| 
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| static void gpio_irq_unmask(u32 irq)
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| {
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| 	int pin = irq_to_gpio(irq);
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| 	int type = irq_desc[irq].status & IRQ_TYPE_SENSE_MASK;
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| 	u32 reg = (type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING)) ?
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| 		GPIO_EDGE_MASK(pin) : GPIO_LEVEL_MASK(pin);
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| 	u32 u = readl(reg);
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| 	u |= 1 << (pin & 31);
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| 	writel(u, reg);
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| }
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| 
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| static int gpio_irq_set_type(u32 irq, u32 type)
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| {
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| 	int pin = irq_to_gpio(irq);
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| 	struct irq_desc *desc;
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| 	u32 u;
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| 
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| 	u = readl(GPIO_IO_CONF(pin)) & (1 << (pin & 31));
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| 	if (!u) {
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| 		printk(KERN_ERR "orion gpio_irq_set_type failed "
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| 				"(irq %d, pin %d).\n", irq, pin);
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| 		return -EINVAL;
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| 	}
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| 
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| 	desc = irq_desc + irq;
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| 
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| 	/*
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| 	 * Set edge/level type.
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| 	 */
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| 	if (type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING)) {
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| 		desc->handle_irq = handle_edge_irq;
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| 	} else if (type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
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| 		desc->handle_irq = handle_level_irq;
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| 	} else {
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| 		printk(KERN_ERR "failed to set irq=%d (type=%d)\n", irq, type);
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| 		return -EINVAL;
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| 	}
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| 
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| 	/*
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| 	 * Configure interrupt polarity.
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| 	 */
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| 	if (type == IRQ_TYPE_EDGE_RISING || type == IRQ_TYPE_LEVEL_HIGH) {
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| 		u = readl(GPIO_IN_POL(pin));
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| 		u &= ~(1 << (pin & 31));
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| 		writel(u, GPIO_IN_POL(pin));
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| 	} else if (type == IRQ_TYPE_EDGE_FALLING || type == IRQ_TYPE_LEVEL_LOW) {
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| 		u = readl(GPIO_IN_POL(pin));
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| 		u |= 1 << (pin & 31);
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| 		writel(u, GPIO_IN_POL(pin));
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| 	} else if (type == IRQ_TYPE_EDGE_BOTH) {
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| 		u32 v;
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| 
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| 		v = readl(GPIO_IN_POL(pin)) ^ readl(GPIO_DATA_IN(pin));
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| 
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| 		/*
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| 		 * set initial polarity based on current input level
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| 		 */
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| 		u = readl(GPIO_IN_POL(pin));
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| 		if (v & (1 << (pin & 31)))
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| 			u |= 1 << (pin & 31);		/* falling */
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| 		else
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| 			u &= ~(1 << (pin & 31));	/* rising */
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| 		writel(u, GPIO_IN_POL(pin));
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| 	}
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| 
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| 	desc->status = (desc->status & ~IRQ_TYPE_SENSE_MASK) | type;
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| 
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| 	return 0;
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| }
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| 
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| struct irq_chip orion_gpio_irq_chip = {
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| 	.name		= "orion_gpio_irq",
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| 	.ack		= gpio_irq_ack,
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| 	.mask		= gpio_irq_mask,
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| 	.unmask		= gpio_irq_unmask,
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| 	.set_type	= gpio_irq_set_type,
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| };
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| 
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| void orion_gpio_irq_handler(int pinoff)
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| {
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| 	u32 cause;
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| 	int pin;
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| 
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| 	cause = readl(GPIO_DATA_IN(pinoff)) & readl(GPIO_LEVEL_MASK(pinoff));
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| 	cause |= readl(GPIO_EDGE_CAUSE(pinoff)) & readl(GPIO_EDGE_MASK(pinoff));
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| 
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| 	for (pin = pinoff; pin < pinoff + 8; pin++) {
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| 		int irq = gpio_to_irq(pin);
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| 		struct irq_desc *desc = irq_desc + irq;
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| 
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| 		if (!(cause & (1 << (pin & 31))))
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| 			continue;
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| 
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| 		if ((desc->status & IRQ_TYPE_SENSE_MASK) == IRQ_TYPE_EDGE_BOTH) {
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| 			/* Swap polarity (race with GPIO line) */
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| 			u32 polarity;
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| 
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| 			polarity = readl(GPIO_IN_POL(pin));
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| 			polarity ^= 1 << (pin & 31);
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| 			writel(polarity, GPIO_IN_POL(pin));
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| 		}
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| 		desc_handle_irq(irq, desc);
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| 	}
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| }
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