Commit 70cc2c00 authored by Gregory Bean's avatar Gregory Bean Committed by Daniel Walker
Browse files

msm: gpio: Add irq support to v2 gpiolib. 



Complete the MSM v2 gpio subsystem by adding irq_chip.

Signed-off-by: default avatarGregory Bean <gbean@codeaurora.org>
Signed-off-by: default avatarDaniel Walker <dwalker@codeaurora.org>
parent 0cc2fc1f

arch/arm/mach-msm/gpio-v2.c

+286 −23
Original line number Diff line number Diff line
@@ -15,7 +15,13 @@ 
 * 02110-1301, USA.

 *

 */

#define pr_fmt(fmt) "%s: " fmt, __func__



#include <linux/bitmap.h>

#include <linux/bitops.h>

#include <linux/gpio.h>

#include <linux/init.h>

#include <linux/interrupt.h>

#include <linux/io.h>

#include <linux/irq.h>

#include <linux/module.h>
@@ -27,29 +33,103 @@ 
/* Bits of interest in the GPIO_IN_OUT register.

 */

enum {

	GPIO_IN_BIT  = 0,

	GPIO_OUT_BIT = 1

	GPIO_IN  = 0,

	GPIO_OUT = 1

};



/* Bits of interest in the GPIO_INTR_STATUS register.

 */

enum {

	INTR_STATUS = 0,

};



/* Bits of interest in the GPIO_CFG register.

 */

enum {

	GPIO_OE_BIT = 9,

	GPIO_OE = 9,

};



/* Bits of interest in the GPIO_INTR_CFG register.

 * When a GPIO triggers, two separate decisions are made, controlled

 * by two separate flags.

 *

 * - First, INTR_RAW_STATUS_EN controls whether or not the GPIO_INTR_STATUS

 * register for that GPIO will be updated to reflect the triggering of that

 * gpio.  If this bit is 0, this register will not be updated.

 * - Second, INTR_ENABLE controls whether an interrupt is triggered.

 *

 * If INTR_ENABLE is set and INTR_RAW_STATUS_EN is NOT set, an interrupt

 * can be triggered but the status register will not reflect it.

 */

enum {

	INTR_ENABLE        = 0,

	INTR_POL_CTL       = 1,

	INTR_DECT_CTL      = 2,

	INTR_RAW_STATUS_EN = 3,

};



/* Codes of interest in GPIO_INTR_CFG_SU.

 */

enum {

	TARGET_PROC_SCORPION = 4,

	TARGET_PROC_NONE     = 7,

};





#define GPIO_INTR_CFG_SU(gpio)    (MSM_TLMM_BASE + 0x0400 + (0x04 * (gpio)))

#define GPIO_CONFIG(gpio)         (MSM_TLMM_BASE + 0x1000 + (0x10 * (gpio)))

#define GPIO_IN_OUT(gpio)         (MSM_TLMM_BASE + 0x1004 + (0x10 * (gpio)))

#define GPIO_INTR_CFG(gpio)       (MSM_TLMM_BASE + 0x1008 + (0x10 * (gpio)))

#define GPIO_INTR_STATUS(gpio)    (MSM_TLMM_BASE + 0x100c + (0x10 * (gpio)))



/**

 * struct msm_gpio_dev: the MSM8660 SoC GPIO device structure

 *

 * @enabled_irqs: a bitmap used to optimize the summary-irq handler.  By

 * keeping track of which gpios are unmasked as irq sources, we avoid

 * having to do readl calls on hundreds of iomapped registers each time

 * the summary interrupt fires in order to locate the active interrupts.

 *

 * @wake_irqs: a bitmap for tracking which interrupt lines are enabled

 * as wakeup sources.  When the device is suspended, interrupts which are

 * not wakeup sources are disabled.

 *

 * @dual_edge_irqs: a bitmap used to track which irqs are configured

 * as dual-edge, as this is not supported by the hardware and requires

 * some special handling in the driver.

 */

struct msm_gpio_dev {

	struct gpio_chip gpio_chip;

	DECLARE_BITMAP(enabled_irqs, NR_GPIO_IRQS);

	DECLARE_BITMAP(wake_irqs, NR_GPIO_IRQS);

	DECLARE_BITMAP(dual_edge_irqs, NR_GPIO_IRQS);

};



static DEFINE_SPINLOCK(tlmm_lock);



static inline struct msm_gpio_dev *to_msm_gpio_dev(struct gpio_chip *chip)

{

	return container_of(chip, struct msm_gpio_dev, gpio_chip);

}



static inline void set_gpio_bits(unsigned n, void __iomem *reg)

{

	writel(readl(reg) | n, reg);

}



static inline void clear_gpio_bits(unsigned n, void __iomem *reg)

{

	writel(readl(reg) & ~n, reg);

}



static int msm_gpio_get(struct gpio_chip *chip, unsigned offset)

{

	return readl(GPIO_IN_OUT(offset)) & BIT(GPIO_IN_BIT);

	return readl(GPIO_IN_OUT(offset)) & BIT(GPIO_IN);

}



static void msm_gpio_set(struct gpio_chip *chip, unsigned offset, int val)

{

	writel(val ? BIT(GPIO_OUT_BIT) : 0, GPIO_IN_OUT(offset));

	writel(val ? BIT(GPIO_OUT) : 0, GPIO_IN_OUT(offset));

}



static int msm_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
@@ -57,8 +137,7 @@ static int msm_gpio_direction_input(struct gpio_chip *chip, unsigned offset) 
	unsigned long irq_flags;



	spin_lock_irqsave(&tlmm_lock, irq_flags);

	writel(readl(GPIO_CONFIG(offset)) & ~BIT(GPIO_OE_BIT),

		GPIO_CONFIG(offset));

	clear_gpio_bits(BIT(GPIO_OE), GPIO_CONFIG(offset));

	spin_unlock_irqrestore(&tlmm_lock, irq_flags);

	return 0;

}
@@ -71,8 +150,7 @@ static int msm_gpio_direction_output(struct gpio_chip *chip, 


	spin_lock_irqsave(&tlmm_lock, irq_flags);

	msm_gpio_set(chip, offset, val);

	writel(readl(GPIO_CONFIG(offset)) | BIT(GPIO_OE_BIT),

		GPIO_CONFIG(offset));

	set_gpio_bits(BIT(GPIO_OE), GPIO_CONFIG(offset));

	spin_unlock_irqrestore(&tlmm_lock, irq_flags);

	return 0;

}
@@ -87,30 +165,215 @@ static void msm_gpio_free(struct gpio_chip *chip, unsigned offset) 
	msm_gpiomux_put(chip->base + offset);

}



static struct gpio_chip msm_gpio = {

static int msm_gpio_to_irq(struct gpio_chip *chip, unsigned offset)

{

	return MSM_GPIO_TO_INT(chip->base + offset);

}



static inline int msm_irq_to_gpio(struct gpio_chip *chip, unsigned irq)

{

	return irq - MSM_GPIO_TO_INT(chip->base);

}



static struct msm_gpio_dev msm_gpio = {

	.gpio_chip = {

		.base             = 0,

		.ngpio            = NR_GPIO_IRQS,

		.direction_input  = msm_gpio_direction_input,

		.direction_output = msm_gpio_direction_output,

		.get              = msm_gpio_get,

		.set              = msm_gpio_set,

		.to_irq           = msm_gpio_to_irq,

		.request          = msm_gpio_request,

		.free             = msm_gpio_free,

	},

};



static int __devinit msm_gpio_probe(struct platform_device *dev)

/* For dual-edge interrupts in software, since the hardware has no

 * such support:

 *

 * At appropriate moments, this function may be called to flip the polarity

 * settings of both-edge irq lines to try and catch the next edge.

 *

 * The attempt is considered successful if:

 * - the status bit goes high, indicating that an edge was caught, or

 * - the input value of the gpio doesn't change during the attempt.

 * If the value changes twice during the process, that would cause the first

 * test to fail but would force the second, as two opposite

 * transitions would cause a detection no matter the polarity setting.

 *

 * The do-loop tries to sledge-hammer closed the timing hole between

 * the initial value-read and the polarity-write - if the line value changes

 * during that window, an interrupt is lost, the new polarity setting is

 * incorrect, and the first success test will fail, causing a retry.

 *

 * Algorithm comes from Google's msmgpio driver, see mach-msm/gpio.c.

 */

static void msm_gpio_update_dual_edge_pos(unsigned gpio)

{

	int ret;

	int loop_limit = 100;

	unsigned val, val2, intstat;



	do {

		val = readl(GPIO_IN_OUT(gpio)) & BIT(GPIO_IN);

		if (val)

			clear_gpio_bits(BIT(INTR_POL_CTL), GPIO_INTR_CFG(gpio));

		else

			set_gpio_bits(BIT(INTR_POL_CTL), GPIO_INTR_CFG(gpio));

		val2 = readl(GPIO_IN_OUT(gpio)) & BIT(GPIO_IN);

		intstat = readl(GPIO_INTR_STATUS(gpio)) & BIT(INTR_STATUS);

		if (intstat || val == val2)

			return;

	} while (loop_limit-- > 0);

	pr_err("dual-edge irq failed to stabilize, "

	       "interrupts dropped. %#08x != %#08x\n",

	       val, val2);

}



	msm_gpio.label = dev->name;

	ret = gpiochip_add(&msm_gpio);

static void msm_gpio_irq_ack(unsigned int irq)

{

	int gpio = msm_irq_to_gpio(&msm_gpio.gpio_chip, irq);



	writel(BIT(INTR_STATUS), GPIO_INTR_STATUS(gpio));

	if (test_bit(gpio, msm_gpio.dual_edge_irqs))

		msm_gpio_update_dual_edge_pos(gpio);

}



static void msm_gpio_irq_mask(unsigned int irq)

{

	int gpio = msm_irq_to_gpio(&msm_gpio.gpio_chip, irq);

	unsigned long irq_flags;



	spin_lock_irqsave(&tlmm_lock, irq_flags);

	writel(TARGET_PROC_NONE, GPIO_INTR_CFG_SU(gpio));

	clear_gpio_bits(INTR_RAW_STATUS_EN | INTR_ENABLE, GPIO_INTR_CFG(gpio));

	__clear_bit(gpio, msm_gpio.enabled_irqs);

	spin_unlock_irqrestore(&tlmm_lock, irq_flags);

}



static void msm_gpio_irq_unmask(unsigned int irq)

{

	int gpio = msm_irq_to_gpio(&msm_gpio.gpio_chip, irq);

	unsigned long irq_flags;



	spin_lock_irqsave(&tlmm_lock, irq_flags);

	__set_bit(gpio, msm_gpio.enabled_irqs);

	set_gpio_bits(INTR_RAW_STATUS_EN | INTR_ENABLE, GPIO_INTR_CFG(gpio));

	writel(TARGET_PROC_SCORPION, GPIO_INTR_CFG_SU(gpio));

	spin_unlock_irqrestore(&tlmm_lock, irq_flags);

}



static int msm_gpio_irq_set_type(unsigned int irq, unsigned int flow_type)

{

	int gpio = msm_irq_to_gpio(&msm_gpio.gpio_chip, irq);

	unsigned long irq_flags;

	uint32_t bits;



	spin_lock_irqsave(&tlmm_lock, irq_flags);



	bits = readl(GPIO_INTR_CFG(gpio));



	if (flow_type & IRQ_TYPE_EDGE_BOTH) {

		bits |= BIT(INTR_DECT_CTL);

		irq_desc[irq].handle_irq = handle_edge_irq;

		if ((flow_type & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH)

			__set_bit(gpio, msm_gpio.dual_edge_irqs);

		else

			__clear_bit(gpio, msm_gpio.dual_edge_irqs);

	} else {

		bits &= ~BIT(INTR_DECT_CTL);

		irq_desc[irq].handle_irq = handle_level_irq;

		__clear_bit(gpio, msm_gpio.dual_edge_irqs);

	}



	if (flow_type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_LEVEL_HIGH))

		bits |= BIT(INTR_POL_CTL);

	else

		bits &= ~BIT(INTR_POL_CTL);



	writel(bits, GPIO_INTR_CFG(gpio));



	if ((flow_type & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH)

		msm_gpio_update_dual_edge_pos(gpio);



	spin_unlock_irqrestore(&tlmm_lock, irq_flags);



	return 0;

}



/*

 * When the summary IRQ is raised, any number of GPIO lines may be high.

 * It is the job of the summary handler to find all those GPIO lines

 * which have been set as summary IRQ lines and which are triggered,

 * and to call their interrupt handlers.

 */

static void msm_summary_irq_handler(unsigned int irq, struct irq_desc *desc)

{

	unsigned long i;



	for (i = find_first_bit(msm_gpio.enabled_irqs, NR_GPIO_IRQS);

	     i < NR_GPIO_IRQS;

	     i = find_next_bit(msm_gpio.enabled_irqs, NR_GPIO_IRQS, i + 1)) {

		if (readl(GPIO_INTR_STATUS(i)) & BIT(INTR_STATUS))

			generic_handle_irq(msm_gpio_to_irq(&msm_gpio.gpio_chip,

							   i));

	}

	desc->chip->ack(irq);

}



static int msm_gpio_irq_set_wake(unsigned int irq, unsigned int on)

{

	int gpio = msm_irq_to_gpio(&msm_gpio.gpio_chip, irq);



	if (on) {

		if (bitmap_empty(msm_gpio.wake_irqs, NR_GPIO_IRQS))

			set_irq_wake(TLMM_SCSS_SUMMARY_IRQ, 1);

		set_bit(gpio, msm_gpio.wake_irqs);

	} else {

		clear_bit(gpio, msm_gpio.wake_irqs);

		if (bitmap_empty(msm_gpio.wake_irqs, NR_GPIO_IRQS))

			set_irq_wake(TLMM_SCSS_SUMMARY_IRQ, 0);

	}



	return 0;

}



static struct irq_chip msm_gpio_irq_chip = {

	.name		= "msmgpio",

	.mask		= msm_gpio_irq_mask,

	.unmask		= msm_gpio_irq_unmask,

	.ack		= msm_gpio_irq_ack,

	.set_type	= msm_gpio_irq_set_type,

	.set_wake	= msm_gpio_irq_set_wake,

};



static int __devinit msm_gpio_probe(struct platform_device *dev)

{

	int i, irq, ret;



	bitmap_zero(msm_gpio.enabled_irqs, NR_GPIO_IRQS);

	bitmap_zero(msm_gpio.wake_irqs, NR_GPIO_IRQS);

	bitmap_zero(msm_gpio.dual_edge_irqs, NR_GPIO_IRQS);

	msm_gpio.gpio_chip.label = dev->name;

	ret = gpiochip_add(&msm_gpio.gpio_chip);

	if (ret < 0)

		return ret;



	for (i = 0; i < msm_gpio.gpio_chip.ngpio; ++i) {

		irq = msm_gpio_to_irq(&msm_gpio.gpio_chip, i);

		set_irq_chip(irq, &msm_gpio_irq_chip);

		set_irq_handler(irq, handle_level_irq);

		set_irq_flags(irq, IRQF_VALID);

	}



	set_irq_chained_handler(TLMM_SCSS_SUMMARY_IRQ,

				msm_summary_irq_handler);

	return 0;

}



static int __devexit msm_gpio_remove(struct platform_device *dev)

{

	int ret = gpiochip_remove(&msm_gpio);

	int ret = gpiochip_remove(&msm_gpio.gpio_chip);



	if (ret < 0)

		return ret;