diff options
Diffstat (limited to 'drivers/gpio/gpio-msm-v2.c')
| -rw-r--r-- | drivers/gpio/gpio-msm-v2.c | 433 |
1 files changed, 433 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-msm-v2.c b/drivers/gpio/gpio-msm-v2.c new file mode 100644 index 0000000..5cb1227 --- /dev/null +++ b/drivers/gpio/gpio-msm-v2.c @@ -0,0 +1,433 @@ +/* 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/irq.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/spinlock.h> + +#include <asm/mach/irq.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 (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)); + } + + 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 __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); + 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 __devexit 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 = __devexit_p(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"); |
