/* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 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/irqchip/chained_irq.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
#include <mach/msm_gpiomux.h>
#include <mach/msm_iomap.h>
/* Bits of interest in the GPIO_IN_OUT register.
*/
enum {
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 = 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);
}
static void msm_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
{
writel(val ? BIT(GPIO_OUT) : 0, GPIO_IN_OUT(offset));
}
static int msm_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
unsigned long irq_flags;
spin_lock_irqsave(&tlmm_lock, irq_flags);
clear_gpio_bits(BIT(GPIO_OE), GPIO_CONFIG(offset));
spin_unlock_irqrestore(&tlmm_lock, irq_flags);
return 0;
}
static int msm_gpio_direction_output(struct gpio_chip *chip,
unsigned offset,
int val)
{
unsigned long irq_flags;
spin_lock_irqsave(&tlmm_lock, irq_flags);
msm_gpio_set(chip, offset, val);
set_gpio_bits(BIT(GPIO_OE), GPIO_CONFIG(offset));
spin_unlock_irqrestore(&tlmm_lock, irq_flags);
return 0;
}
static int msm_gpio_request(struct gpio_chip *chip, unsigned offset)
{
return msm_gpiomux_get(chip->base + offset);
}
static void msm_gpio_free(struct gpio_chip *chip, unsigned offset)
{
msm_gpiomux_put(chip->base + offset);
}
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,
},
};
/* 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 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);
}
static void msm_gpio_irq_ack(struct irq_data *d)
{
int gpio = msm_irq_to_gpio(&msm_gpio.gpio_chip, d->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(struct irq_data *d)
{
int gpio = msm_irq_to_gpio(&msm_gpio.gpio_chip, d->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(struct irq_data *d)
{
int gpio = msm_irq_to_gpio(&msm_gpio.gpio_chip, d->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(struct irq_data *d, unsigned int flow_type)
{
int gpio = msm_irq_to_gpio(&msm_gpio.gpio_chip, d->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_set_handler_locked(d->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_set_handler_locked(d->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;
struct irq_chip *chip = irq_desc_get_chip(desc);
chained_irq_enter(chip, desc);
for_each_set_bit(i, msm_gpio.enabled_irqs, NR_GPIO_IRQS) {
if (readl(GPIO_INTR_STATUS(i)) & BIT(INTR_STATUS))
generic_handle_irq(msm_gpio_to_irq(&msm_gpio.gpio_chip,
i));
}
chained_irq_exit(chip, desc);
}
static int msm_gpio_irq_set_wake(struct irq_data *d, unsigned int on)
{
int gpio = msm_irq_to_gpio(&msm_gpio.gpio_chip, d->irq);
if (on) {
if (bitmap_empty(msm_gpio.wake_irqs, NR_GPIO_IRQS))
irq_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))
irq_set_irq_wake(TLMM_SCSS_SUMMARY_IRQ, 0);
}
return 0;
}
static struct irq_chip msm_gpio_irq_chip = {
.name = "msmgpio",
.irq_mask = msm_gpio_irq_mask,
.irq_unmask = msm_gpio_irq_unmask,
.irq_ack = msm_gpio_irq_ack,
.irq_set_type = msm_gpio_irq_set_type,
.irq_set_wake = msm_gpio_irq_set_wake,
};
static int 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);
irq_set_chip_and_handler(irq, &msm_gpio_irq_chip,
handle_level_irq);
set_irq_flags(irq, IRQF_VALID);
}
irq_set_chained_handler(TLMM_SCSS_SUMMARY_IRQ,
msm_summary_irq_handler);
return 0;
}
static int msm_gpio_remove(struct platform_device *dev)
{
int ret = gpiochip_remove(&msm_gpio.gpio_chip);
if (ret < 0)
return ret;
irq_set_handler(TLMM_SCSS_SUMMARY_IRQ, NULL);
return 0;
}
static struct platform_driver msm_gpio_driver = {
.probe = msm_gpio_probe,
.remove = msm_gpio_remove,
.driver = {
.name = "msmgpio",
.owner = THIS_MODULE,
},
};
static struct platform_device msm_device_gpio = {
.name = "msmgpio",
.id = -1,
};
static int __init msm_gpio_init(void)
{
int rc;
rc = platform_driver_register(&msm_gpio_driver);
if (!rc) {
rc = platform_device_register(&msm_device_gpio);
if (rc)
platform_driver_unregister(&msm_gpio_driver);
}
return rc;
}
static void __exit msm_gpio_exit(void)
{
platform_device_unregister(&msm_device_gpio);
platform_driver_unregister(&msm_gpio_driver);
}
postcore_initcall(msm_gpio_init);
module_exit(msm_gpio_exit);
MODULE_AUTHOR("Gregory Bean <gbean@codeaurora.org>");
MODULE_DESCRIPTION("Driver for Qualcomm MSM TLMMv2 SoC GPIOs");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:msmgpio");
