/* * Support functions for OMAP GPIO * * Copyright (C) 2003-2005 Nokia Corporation * Written by Juha Yrjölä * * Copyright (C) 2009 Texas Instruments * Added OMAP4 support - Santosh Shilimkar * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* for omap4_trigger_ioctrl */ #include "../mux.h" static LIST_HEAD(omap_gpio_list); struct gpio_regs { u32 irqenable1; u32 irqenable2; u32 wake_en; u32 ctrl; u32 oe; u32 leveldetect0; u32 leveldetect1; u32 risingdetect; u32 fallingdetect; u32 dataout; u32 debounce; u32 debounce_en; u32 edge_falling; u32 edge_rising; u32 ew_leveldetect0; u32 ew_leveldetect1; u32 pad_set_wakeupenable; }; struct gpio_bank { struct list_head node; unsigned long pbase; void __iomem *base; u16 irq; u16 virtual_irq_start; u32 suspend_wakeup; u32 saved_wakeup; u32 non_wakeup_gpios; u32 enabled_non_wakeup_gpios; struct gpio_regs context; u32 saved_datain; u32 saved_fallingdetect; u32 saved_risingdetect; u32 level_mask; u32 toggle_mask; spinlock_t lock; struct gpio_chip chip; struct clk *dbck; u32 mod_usage; u32 dbck_enable_mask; struct device *dev; bool is_mpuio; bool dbck_flag; bool loses_context; bool suspend_support; bool saved_context; int stride; u32 width; u16 id; u32 type_leveldetect0; u32 type_leveldetect1; u32 type_risingedge; u32 type_fallingedge; void (*set_dataout)(struct gpio_bank *bank, int gpio, int enable); struct omap_gpio_reg_offs *regs; struct omap_mux *mux[32]; }; static void omap_gpio_mod_init(struct gpio_bank *bank); #define GPIO_INDEX(bank, gpio) (gpio % bank->width) #define GPIO_BIT(bank, gpio) (1 << GPIO_INDEX(bank, gpio)) #define GPIO_MOD_CTRL_BIT BIT(0) static void _set_gpio_waken(struct gpio_bank *bank, int gpio) { if (bank->regs->wkup_set != bank->regs->wkup_clear) { __raw_writel((1 << gpio), bank->base + bank->regs->wkup_set); } else { u32 val = __raw_readl(bank->base + bank->regs->wkup_set); val |= 1 << gpio; __raw_writel(val, bank->base + bank->regs->wkup_set); } } static void _clear_gpio_waken(struct gpio_bank *bank, int gpio) { if (bank->regs->wkup_set != bank->regs->wkup_clear) { __raw_writel((1 << gpio), bank->base + bank->regs->wkup_clear); } else { u32 val = __raw_readl(bank->base + bank->regs->wkup_clear); val &= ~(1 << gpio); __raw_writel(val, bank->base + bank->regs->wkup_clear); } } static void _set_gpio_direction(struct gpio_bank *bank, int gpio, int is_input) { void __iomem *reg = bank->base; u32 l; reg += bank->regs->direction; l = __raw_readl(reg); if (is_input) l |= 1 << gpio; else l &= ~(1 << gpio); __raw_writel(l, reg); } /* set data out value using dedicate set/clear register */ static void _set_gpio_dataout_reg(struct gpio_bank *bank, int gpio, int enable) { void __iomem *reg = bank->base; u32 l = GPIO_BIT(bank, gpio); if (enable) reg += bank->regs->set_dataout; else reg += bank->regs->clr_dataout; __raw_writel(l, reg); } /* set data out value using mask register */ static void _set_gpio_dataout_mask(struct gpio_bank *bank, int gpio, int enable) { void __iomem *reg = bank->base + bank->regs->dataout; u32 gpio_bit = GPIO_BIT(bank, gpio); u32 l; l = __raw_readl(reg); if (enable) l |= gpio_bit; else l &= ~gpio_bit; __raw_writel(l, reg); } static int _get_gpio_datain(struct gpio_bank *bank, int gpio) { void __iomem *reg = bank->base + bank->regs->datain; return (__raw_readl(reg) & GPIO_BIT(bank, gpio)) != 0; } static int _get_gpio_dataout(struct gpio_bank *bank, int gpio) { void __iomem *reg = bank->base + bank->regs->dataout; return (__raw_readl(reg) & GPIO_BIT(bank, gpio)) != 0; } #define MOD_REG_BIT(reg, bit_mask, set) \ do { \ int l = __raw_readl(base + reg); \ if (set) l |= bit_mask; \ else l &= ~bit_mask; \ __raw_writel(l, base + reg); \ } while(0) /** * _set_gpio_debounce - low level gpio debounce time * @bank: the gpio bank we're acting upon * @gpio: the gpio number on this @gpio * @debounce: debounce time to use * * OMAP's debounce time is in 31us steps so we need * to convert and round up to the closest unit. */ static void _set_gpio_debounce(struct gpio_bank *bank, unsigned gpio, unsigned debounce) { void __iomem *reg; u32 val; u32 l; if (!bank->dbck_flag) return; if (debounce < 32) debounce = 0x01; else if (debounce > 7936) debounce = 0xff; else debounce = (debounce / 0x1f) - 1; l = GPIO_BIT(bank, gpio); reg = bank->base + bank->regs->debounce; __raw_writel(debounce, reg); reg = bank->base + bank->regs->debounce_en; val = __raw_readl(reg); if (debounce) { val |= l; clk_enable(bank->dbck); } else { val &= ~l; clk_disable(bank->dbck); } bank->dbck_enable_mask = val; __raw_writel(val, reg); } static inline void set_gpio_trigger(struct gpio_bank *bank, int gpio, int trigger) { void __iomem *base = bank->base; u32 gpio_bit = 1 << gpio; MOD_REG_BIT(bank->regs->leveldetect0, gpio_bit, trigger & IRQ_TYPE_LEVEL_LOW); MOD_REG_BIT(bank->regs->leveldetect1, gpio_bit, trigger & IRQ_TYPE_LEVEL_HIGH); MOD_REG_BIT(bank->regs->risingdetect, gpio_bit, trigger & IRQ_TYPE_EDGE_RISING); MOD_REG_BIT(bank->regs->fallingdetect, gpio_bit, trigger & IRQ_TYPE_EDGE_FALLING); if (likely(!(bank->non_wakeup_gpios & gpio_bit))) { if (cpu_is_omap44xx()) { MOD_REG_BIT(bank->regs->wkup_status, gpio_bit, trigger != 0); } else { /* * GPIO wakeup request can only be generated on edge * transitions */ if (trigger & IRQ_TYPE_EDGE_BOTH) _set_gpio_waken(bank, gpio); else _clear_gpio_waken(bank, gpio); } } /* This part needs to be executed always for OMAP{34xx, 44xx} */ if (cpu_is_omap34xx() || cpu_is_omap44xx() || (bank->non_wakeup_gpios & gpio_bit)) { /* * Log the edge gpio and manually trigger the IRQ * after resume if the input level changes * to avoid irq lost during PER RET/OFF mode * Applies for omap2 non-wakeup gpio and all omap3 gpios */ if (trigger & IRQ_TYPE_EDGE_BOTH) bank->enabled_non_wakeup_gpios |= gpio_bit; else bank->enabled_non_wakeup_gpios &= ~gpio_bit; } bank->level_mask = __raw_readl(bank->base + bank->regs->leveldetect0) | __raw_readl(bank->base + bank->regs->leveldetect1); } #ifdef CONFIG_ARCH_OMAP1 /* * This only applies to chips that can't do both rising and falling edge * detection at once. For all other chips, this function is a noop. */ static void _toggle_gpio_edge_triggering(struct gpio_bank *bank, int gpio) { void __iomem *reg = bank->base; u32 l = 0; if (!bank->regs->irqctrl) return; reg += bank->regs->irqctrl; l = __raw_readl(reg); if ((l >> gpio) & 1) l &= ~(1 << gpio); else l |= 1 << gpio; __raw_writel(l, reg); } #endif static int _set_gpio_triggering(struct gpio_bank *bank, int gpio, int trigger) { void __iomem *reg = bank->base; u32 l = 0; if (bank->regs->leveldetect0 && bank->regs->wkup_status) { set_gpio_trigger(bank, gpio, trigger); } else if (bank->regs->irqctrl) { reg += bank->regs->irqctrl; l = __raw_readl(reg); if ((trigger & IRQ_TYPE_SENSE_MASK) == IRQ_TYPE_EDGE_BOTH) bank->toggle_mask |= 1 << gpio; if (trigger & IRQ_TYPE_EDGE_RISING) l |= 1 << gpio; else if (trigger & IRQ_TYPE_EDGE_FALLING) l &= ~(1 << gpio); else return -EINVAL; __raw_writel(l, reg); } else if (bank->regs->edgectrl1) { if (gpio & 0x08) reg += bank->regs->edgectrl2; else reg += bank->regs->edgectrl1; gpio &= 0x07; l = __raw_readl(reg); l &= ~(3 << (gpio << 1)); if (trigger & IRQ_TYPE_EDGE_RISING) l |= 2 << (gpio << 1); if (trigger & IRQ_TYPE_EDGE_FALLING) l |= 1 << (gpio << 1); if (trigger) /* Enable wake-up during idle for dynamic tick */ _set_gpio_waken(bank, gpio); else _clear_gpio_waken(bank, gpio); __raw_writel(l, reg); } return 0; } static int gpio_irq_type(struct irq_data *d, unsigned type) { struct gpio_bank *bank; unsigned gpio; int retval; unsigned long flags; if (!cpu_class_is_omap2() && d->irq > IH_MPUIO_BASE) gpio = OMAP_MPUIO(d->irq - IH_MPUIO_BASE); else gpio = d->irq - IH_GPIO_BASE; if (type & ~IRQ_TYPE_SENSE_MASK) return -EINVAL; bank = irq_data_get_irq_chip_data(d); /* OMAP1 allows only edge triggering */ if (!bank->regs->leveldetect0 && (type & (IRQ_TYPE_LEVEL_LOW|IRQ_TYPE_LEVEL_HIGH))) return -EINVAL; spin_lock_irqsave(&bank->lock, flags); retval = _set_gpio_triggering(bank, GPIO_INDEX(bank, gpio), type); bank->type_leveldetect0 &= ~GPIO_BIT(bank, gpio); bank->type_leveldetect1 &= ~GPIO_BIT(bank, gpio); bank->type_fallingedge &= ~GPIO_BIT(bank, gpio); bank->type_risingedge &= ~GPIO_BIT(bank, gpio); if (type & IRQ_TYPE_LEVEL_LOW) bank->type_leveldetect0 |= GPIO_BIT(bank, gpio); if (type & IRQ_TYPE_LEVEL_HIGH) bank->type_leveldetect1 |= GPIO_BIT(bank, gpio); if (type & IRQ_TYPE_EDGE_FALLING) bank->type_fallingedge |= GPIO_BIT(bank, gpio); if (type & IRQ_TYPE_EDGE_RISING) bank->type_risingedge |= GPIO_BIT(bank, gpio); spin_unlock_irqrestore(&bank->lock, flags); if (type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH)) __irq_set_handler_locked(d->irq, handle_level_irq); else if (type & (IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING)) __irq_set_handler_locked(d->irq, handle_edge_irq); return retval; } static void _clear_gpio_irqbank(struct gpio_bank *bank, int gpio_mask) { void __iomem *reg = bank->base; reg += bank->regs->irqstatus; __raw_writel(gpio_mask, reg); /* Workaround for clearing DSP GPIO interrupts to allow retention */ if (bank->regs->irqstatus2) { reg = bank->base + bank->regs->irqstatus2; __raw_writel(gpio_mask, reg); } /* Flush posted write for the irq status to avoid spurious interrupts */ __raw_readl(reg); } static inline void _clear_gpio_irqstatus(struct gpio_bank *bank, int gpio) { _clear_gpio_irqbank(bank, GPIO_BIT(bank, gpio)); } static u32 _get_gpio_irqbank_mask(struct gpio_bank *bank) { void __iomem *reg = bank->base; u32 l; u32 mask = (1 << bank->width) - 1; reg += bank->regs->irqenable; l = __raw_readl(reg); if (bank->regs->irqenable_inv) l = ~l; l &= mask; return l; } static void _enable_gpio_irqbank(struct gpio_bank *bank, int gpio_mask) { void __iomem *reg = bank->base; u32 l; if (bank->regs->set_irqenable) { reg += bank->regs->set_irqenable; l = gpio_mask; } else { reg += bank->regs->irqenable; l = __raw_readl(reg); if (bank->regs->irqenable_inv) l &= ~gpio_mask; else l |= gpio_mask; } __raw_writel(l, reg); } static void _disable_gpio_irqbank(struct gpio_bank *bank, int gpio_mask) { void __iomem *reg = bank->base; u32 l; if (bank->regs->clr_irqenable) { reg += bank->regs->clr_irqenable; l = gpio_mask; } else { reg += bank->regs->irqenable; l = __raw_readl(reg); if (bank->regs->irqenable_inv) l |= gpio_mask; else l &= ~gpio_mask; } __raw_writel(l, reg); } static inline void _set_gpio_irqenable(struct gpio_bank *bank, int gpio, int enable) { if (enable) _enable_gpio_irqbank(bank, GPIO_BIT(bank, gpio)); else _disable_gpio_irqbank(bank, GPIO_BIT(bank, gpio)); } /* * Note that ENAWAKEUP needs to be enabled in GPIO_SYSCONFIG register. * 1510 does not seem to have a wake-up register. If JTAG is connected * to the target, system will wake up always on GPIO events. While * system is running all registered GPIO interrupts need to have wake-up * enabled. When system is suspended, only selected GPIO interrupts need * to have wake-up enabled. */ static int _set_gpio_wakeup(struct gpio_bank *bank, int gpio, int enable) { u32 gpio_bit = GPIO_BIT(bank, gpio); unsigned long flags; if (bank->non_wakeup_gpios & gpio_bit) { dev_err(bank->dev, "Unable to modify wakeup on non-wakeup GPIO%d\n", gpio); return -EINVAL; } spin_lock_irqsave(&bank->lock, flags); if (enable) bank->suspend_wakeup |= gpio_bit; else bank->suspend_wakeup &= ~gpio_bit; spin_unlock_irqrestore(&bank->lock, flags); return 0; } static void _reset_gpio(struct gpio_bank *bank, int gpio) { _set_gpio_direction(bank, GPIO_INDEX(bank, gpio), 1); _set_gpio_irqenable(bank, gpio, 0); _clear_gpio_irqstatus(bank, gpio); _set_gpio_triggering(bank, GPIO_INDEX(bank, gpio), IRQ_TYPE_NONE); } /* Use disable_irq_wake() and enable_irq_wake() functions from drivers */ static int gpio_wake_enable(struct irq_data *d, unsigned int enable) { unsigned int gpio = d->irq - IH_GPIO_BASE; struct gpio_bank *bank; int retval; bank = irq_data_get_irq_chip_data(d); retval = _set_gpio_wakeup(bank, gpio, enable); return retval; } static int omap_gpio_request(struct gpio_chip *chip, unsigned offset) { struct gpio_bank *bank = container_of(chip, struct gpio_bank, chip); unsigned long flags; spin_lock_irqsave(&bank->lock, flags); /* * If this is the first gpio_request for the bank, * enable the bank module. */ if (!bank->mod_usage) { if (pm_runtime_get_sync(bank->dev) < 0) { dev_err(bank->dev, "%s: GPIO bank %d " "pm_runtime_get_sync failed\n", __func__, bank->id); spin_unlock_irqrestore(&bank->lock, flags); return -EINVAL; } /* Initialize the gpio bank registers to init time value */ omap_gpio_mod_init(bank); } /* Set trigger to none. You need to enable the desired trigger with * request_irq() or set_irq_type(). */ _set_gpio_triggering(bank, offset, IRQ_TYPE_NONE); if (bank->regs->pinctrl) { void __iomem *reg = bank->base + bank->regs->pinctrl; /* Claim the pin for MPU */ __raw_writel(__raw_readl(reg) | (1 << offset), reg); } if (bank->regs->ctrl && !bank->mod_usage) { void __iomem *reg = bank->base + bank->regs->ctrl; u32 ctrl; ctrl = __raw_readl(reg); /* Module is enabled, clocks are not gated */ ctrl &= ~GPIO_MOD_CTRL_BIT; __raw_writel(ctrl, reg); } bank->mod_usage |= 1 << offset; spin_unlock_irqrestore(&bank->lock, flags); return 0; } static void omap_gpio_free(struct gpio_chip *chip, unsigned offset) { struct gpio_bank *bank = container_of(chip, struct gpio_bank, chip); unsigned long flags; spin_lock_irqsave(&bank->lock, flags); if (bank->regs->wkup_clear) /* Disable wake-up during idle for dynamic tick */ _clear_gpio_waken(bank, offset); bank->mod_usage &= ~(1 << offset); if (bank->regs->ctrl && !bank->mod_usage) { void __iomem *reg = bank->base + bank->regs->ctrl; u32 ctrl; ctrl = __raw_readl(reg); /* Module is disabled, clocks are gated */ ctrl |= GPIO_MOD_CTRL_BIT; __raw_writel(ctrl, reg); } _reset_gpio(bank, bank->chip.base + offset); /* * If this is the last gpio to be freed in the bank, * disable the bank module. */ if (!bank->mod_usage) { if (pm_runtime_put_sync_suspend(bank->dev)) { dev_err(bank->dev, "%s: GPIO bank %d " "pm_runtime_put_sync_suspend failed\n", __func__, bank->id); } } spin_unlock_irqrestore(&bank->lock, flags); } /* * We need to unmask the GPIO bank interrupt as soon as possible to * avoid missing GPIO interrupts for other lines in the bank. * Then we need to mask-read-clear-unmask the triggered GPIO lines * in the bank to avoid missing nested interrupts for a GPIO line. * If we wait to unmask individual GPIO lines in the bank after the * line's interrupt handler has been run, we may miss some nested * interrupts. */ static void gpio_irq_handler(unsigned int irq, struct irq_desc *desc) { void __iomem *isr_reg = NULL; u32 isr; unsigned int gpio_irq, gpio_index; struct gpio_bank *bank; u32 retrigger = 0; int unmasked = 0; struct irq_chip *chip = irq_desc_get_chip(desc); chained_irq_enter(chip, desc); bank = irq_get_handler_data(irq); pm_runtime_get_sync(bank->dev); isr_reg = bank->base + bank->regs->irqstatus; if (WARN_ON(!isr_reg)) goto exit; while(1) { u32 isr_saved, level_mask = 0; u32 enabled; enabled = _get_gpio_irqbank_mask(bank); if (bank->width == 32) isr = __raw_readl(isr_reg) & enabled; else if (bank->width == 16) isr = (__raw_readw(isr_reg) & enabled) & 0x0000ffff; isr_saved = isr; if (bank->regs->leveldetect0) level_mask = bank->level_mask & enabled; /* clear edge sensitive interrupts before handler(s) are called so that we don't miss any interrupt occurred while executing them */ _disable_gpio_irqbank(bank, isr_saved & ~level_mask); _clear_gpio_irqbank(bank, isr_saved & ~level_mask); _enable_gpio_irqbank(bank, isr_saved & ~level_mask); /* if there is only edge sensitive GPIO pin interrupts configured, we could unmask GPIO bank interrupt immediately */ if (!level_mask && !unmasked) { unmasked = 1; chained_irq_exit(chip, desc); } isr |= retrigger; retrigger = 0; if (!isr) break; gpio_irq = bank->virtual_irq_start; for (; isr != 0; isr >>= 1, gpio_irq++) { gpio_index = GPIO_INDEX(bank, irq_to_gpio(gpio_irq)); if (!(isr & 1)) continue; #ifdef CONFIG_ARCH_OMAP1 /* * Some chips can't respond to both rising and falling * at the same time. If this irq was requested with * both flags, we need to flip the ICR data for the IRQ * to respond to the IRQ for the opposite direction. * This will be indicated in the bank toggle_mask. */ if (bank->toggle_mask & (1 << gpio_index)) _toggle_gpio_edge_triggering(bank, gpio_index); #endif generic_handle_irq(gpio_irq); } } /* if bank has any level sensitive GPIO pin interrupt configured, we must unmask the bank interrupt only after handler(s) are executed in order to avoid spurious bank interrupt */ exit: if (!unmasked) chained_irq_exit(chip, desc); pm_runtime_put_sync_suspend(bank->dev); } static void gpio_irq_shutdown(struct irq_data *d) { unsigned int gpio = d->irq - IH_GPIO_BASE; struct gpio_bank *bank = irq_data_get_irq_chip_data(d); unsigned long flags; spin_lock_irqsave(&bank->lock, flags); _reset_gpio(bank, gpio); spin_unlock_irqrestore(&bank->lock, flags); } static void gpio_ack_irq(struct irq_data *d) { unsigned int gpio = d->irq - IH_GPIO_BASE; struct gpio_bank *bank = irq_data_get_irq_chip_data(d); _clear_gpio_irqstatus(bank, gpio); } static void gpio_mask_irq(struct irq_data *d) { unsigned int gpio = d->irq - IH_GPIO_BASE; struct gpio_bank *bank = irq_data_get_irq_chip_data(d); unsigned long flags; spin_lock_irqsave(&bank->lock, flags); _set_gpio_irqenable(bank, gpio, 0); _set_gpio_triggering(bank, GPIO_INDEX(bank, gpio), IRQ_TYPE_NONE); spin_unlock_irqrestore(&bank->lock, flags); } static void gpio_unmask_irq(struct irq_data *d) { unsigned int gpio = d->irq - IH_GPIO_BASE; struct gpio_bank *bank = irq_data_get_irq_chip_data(d); unsigned int irq_mask = GPIO_BIT(bank, gpio); u32 trigger = irqd_get_trigger_type(d); unsigned long flags; spin_lock_irqsave(&bank->lock, flags); if (trigger) _set_gpio_triggering(bank, GPIO_INDEX(bank, gpio), trigger); _set_gpio_irqenable(bank, gpio, 1); /* * For level-triggered GPIOs, the clearing must be done after * the HW source is cleared, thus after the handler has run. * Also, make sure to clear the status _after_ enabling the irq * so that pending event will be cleared. */ if (bank->level_mask & irq_mask) _clear_gpio_irqstatus(bank, gpio); spin_unlock_irqrestore(&bank->lock, flags); } static struct irq_chip gpio_irq_chip = { .name = "GPIO", .irq_shutdown = gpio_irq_shutdown, .irq_ack = gpio_ack_irq, .irq_mask = gpio_mask_irq, .irq_unmask = gpio_unmask_irq, .irq_set_type = gpio_irq_type, .irq_set_wake = gpio_wake_enable, .flags = IRQCHIP_MASK_ON_SUSPEND, }; /*---------------------------------------------------------------------*/ static int omap_mpuio_suspend_noirq(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct gpio_bank *bank = platform_get_drvdata(pdev); void __iomem *mask_reg = bank->base + OMAP_MPUIO_GPIO_MASKIT / bank->stride; unsigned long flags; spin_lock_irqsave(&bank->lock, flags); bank->saved_wakeup = __raw_readl(mask_reg); __raw_writel(0xffff & ~bank->suspend_wakeup, mask_reg); spin_unlock_irqrestore(&bank->lock, flags); return 0; } static int omap_mpuio_resume_noirq(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct gpio_bank *bank = platform_get_drvdata(pdev); void __iomem *mask_reg = bank->base + OMAP_MPUIO_GPIO_MASKIT / bank->stride; unsigned long flags; spin_lock_irqsave(&bank->lock, flags); __raw_writel(bank->saved_wakeup, mask_reg); spin_unlock_irqrestore(&bank->lock, flags); return 0; } static const struct dev_pm_ops omap_mpuio_dev_pm_ops = { .suspend_noirq = omap_mpuio_suspend_noirq, .resume_noirq = omap_mpuio_resume_noirq, }; /* use platform_driver for this. */ static struct platform_driver omap_mpuio_driver = { .driver = { .name = "mpuio", .pm = &omap_mpuio_dev_pm_ops, }, }; static struct platform_device omap_mpuio_device = { .name = "mpuio", .id = -1, .dev = { .driver = &omap_mpuio_driver.driver, } /* could list the /proc/iomem resources */ }; static inline void mpuio_init(struct gpio_bank *bank) { platform_set_drvdata(&omap_mpuio_device, bank); if (platform_driver_register(&omap_mpuio_driver) == 0) (void) platform_device_register(&omap_mpuio_device); } /*---------------------------------------------------------------------*/ static int gpio_input(struct gpio_chip *chip, unsigned offset) { struct gpio_bank *bank; unsigned long flags; bank = container_of(chip, struct gpio_bank, chip); spin_lock_irqsave(&bank->lock, flags); _set_gpio_direction(bank, offset, 1); spin_unlock_irqrestore(&bank->lock, flags); return 0; } static int gpio_is_input(struct gpio_bank *bank, int mask) { void __iomem *reg = bank->base + bank->regs->direction; return __raw_readl(reg) & mask; } static int gpio_get(struct gpio_chip *chip, unsigned offset) { struct gpio_bank *bank; void __iomem *reg; int gpio; u32 mask; gpio = chip->base + offset; bank = container_of(chip, struct gpio_bank, chip); reg = bank->base; mask = GPIO_BIT(bank, gpio); if (gpio_is_input(bank, mask)) return _get_gpio_datain(bank, gpio); else return _get_gpio_dataout(bank, gpio); } static int gpio_output(struct gpio_chip *chip, unsigned offset, int value) { struct gpio_bank *bank; unsigned long flags; bank = container_of(chip, struct gpio_bank, chip); spin_lock_irqsave(&bank->lock, flags); bank->set_dataout(bank, offset, value); _set_gpio_direction(bank, offset, 0); spin_unlock_irqrestore(&bank->lock, flags); return 0; } static int gpio_debounce(struct gpio_chip *chip, unsigned offset, unsigned debounce) { struct gpio_bank *bank; unsigned long flags; bank = container_of(chip, struct gpio_bank, chip); if (!bank->dbck) { bank->dbck = clk_get(bank->dev, "dbclk"); if (IS_ERR(bank->dbck)) dev_err(bank->dev, "Could not get gpio dbck\n"); } spin_lock_irqsave(&bank->lock, flags); _set_gpio_debounce(bank, offset, debounce); spin_unlock_irqrestore(&bank->lock, flags); return 0; } static void gpio_set(struct gpio_chip *chip, unsigned offset, int value) { struct gpio_bank *bank; unsigned long flags; bank = container_of(chip, struct gpio_bank, chip); spin_lock_irqsave(&bank->lock, flags); bank->set_dataout(bank, offset, value); spin_unlock_irqrestore(&bank->lock, flags); } static int gpio_2irq(struct gpio_chip *chip, unsigned offset) { struct gpio_bank *bank; bank = container_of(chip, struct gpio_bank, chip); return bank->virtual_irq_start + offset; } /*---------------------------------------------------------------------*/ static void __init omap_gpio_show_rev(struct gpio_bank *bank) { static bool called; u32 rev; if (called || bank->regs->revision == USHRT_MAX) return; rev = __raw_readw(bank->base + bank->regs->revision); pr_info("OMAP GPIO hardware version %d.%d\n", (rev >> 4) & 0x0f, rev & 0x0f); called = true; } /* This lock class tells lockdep that GPIO irqs are in a different * category than their parents, so it won't report false recursion. */ static struct lock_class_key gpio_lock_class; static void omap_gpio_mod_init(struct gpio_bank *bank) { int i; if (bank->width == 32) { u32 clr_all = 0; /* clear all the bits */ u32 set_all = 0xFFFFFFFF; /* set all the bits */ if (bank->is_mpuio) { __raw_writel(set_all, bank->base + bank->regs->irqenable); if (bank->suspend_support) mpuio_init(bank); return; } if (bank->regs->ctrl) /* Initialize interface clk ungated, module enabled */ __raw_writel(clr_all, bank->base + bank->regs->ctrl); if (bank->regs->clr_irqenable) { __raw_writel(set_all, bank->base + bank->regs->clr_irqenable); } else if (bank->regs->irqenable) { u32 i; if (bank->regs->irqenable_inv) i = set_all; else i = clr_all; __raw_writel(i, bank->base + bank->regs->irqenable); } if (bank->regs->irqstatus) { u32 i; if (bank->regs->irqenable_inv) i = clr_all; else i = set_all; __raw_writel(i, bank->base + bank->regs->irqstatus); } if (bank->regs->debounce_en) __raw_writel(clr_all, bank->base + bank->regs->debounce_en); } else if (bank->width == 16) { u16 clr_all = 0; /* clear all the bits */ u16 set_all = 0xFFFF; /* set all the bits */ if (bank->is_mpuio) { __raw_writew(set_all, bank->base + bank->regs->irqenable); if (bank->suspend_support) mpuio_init(bank); return; } if (bank->regs->irqenable) { u16 i; if (bank->regs->irqenable_inv) i = set_all; else i = clr_all; __raw_writew(i, bank->base + bank->regs->irqenable); } if (bank->regs->irqstatus) { u32 i; if (bank->regs->irqenable_inv) i = clr_all; else i = set_all; __raw_writew(i, bank->base + bank->regs->irqstatus); } if (bank->regs->sysconfig) { /* set wakeup-enable and smart-idle */ __raw_writew(0x14, bank->base + bank->regs->sysconfig); /* * Enable system clock for GPIO module. * The CAM_CLK_CTRL *is* really the right place. */ omap_writel(omap_readl(ULPD_CAM_CLK_CTRL) | 0x04, ULPD_CAM_CLK_CTRL); } } for (i = 0; i < bank->width; i++) { int gpio = irq_to_gpio(bank->virtual_irq_start + i); bank->mux[i] = omap_mux_get_gpio(gpio); } } static __init void omap_mpuio_alloc_gc(struct gpio_bank *bank, unsigned int irq_start, unsigned int num) { struct irq_chip_generic *gc; struct irq_chip_type *ct; gc = irq_alloc_generic_chip("MPUIO", 1, irq_start, bank->base, handle_simple_irq); if (!gc) { dev_err(bank->dev, "Memory alloc failed for gc\n"); return; } ct = gc->chip_types; /* NOTE: No ack required, reading IRQ status clears it. */ ct->chip.irq_mask = irq_gc_mask_set_bit; ct->chip.irq_unmask = irq_gc_mask_clr_bit; ct->chip.irq_set_type = gpio_irq_type; if (bank->suspend_support) ct->chip.irq_set_wake = gpio_wake_enable, ct->regs.mask = OMAP_MPUIO_GPIO_INT / bank->stride; irq_setup_generic_chip(gc, IRQ_MSK(num), IRQ_GC_INIT_MASK_CACHE, IRQ_NOREQUEST | IRQ_NOPROBE, 0); } static void __devinit omap_gpio_chip_init(struct gpio_bank *bank) { int j; static int gpio; bank->mod_usage = 0; /* * REVISIT eventually switch from OMAP-specific gpio structs * over to the generic ones */ bank->chip.request = omap_gpio_request; bank->chip.free = omap_gpio_free; bank->chip.direction_input = gpio_input; bank->chip.get = gpio_get; bank->chip.direction_output = gpio_output; bank->chip.set_debounce = gpio_debounce; bank->chip.set = gpio_set; bank->chip.to_irq = gpio_2irq; if (bank->is_mpuio) { bank->chip.label = "mpuio"; if (bank->suspend_support) bank->chip.dev = &omap_mpuio_device.dev; bank->chip.base = OMAP_MPUIO(0); } else { bank->chip.label = "gpio"; bank->chip.base = gpio; gpio += bank->width; } bank->chip.ngpio = bank->width; gpiochip_add(&bank->chip); for (j = bank->virtual_irq_start; j < bank->virtual_irq_start + bank->width; j++) { irq_set_lockdep_class(j, &gpio_lock_class); irq_set_chip_data(j, bank); if (bank->is_mpuio) { omap_mpuio_alloc_gc(bank, j, bank->width); } else { irq_set_chip(j, &gpio_irq_chip); irq_set_handler(j, handle_simple_irq); set_irq_flags(j, IRQF_VALID); } } irq_set_chained_handler(bank->irq, gpio_irq_handler); irq_set_handler_data(bank->irq, bank); } static int __devinit omap_gpio_probe(struct platform_device *pdev) { struct omap_gpio_platform_data *pdata; struct resource *res; struct gpio_bank *bank; int ret = 0; if (!pdev->dev.platform_data) { ret = -EINVAL; goto err_exit; } bank = kzalloc(sizeof(struct gpio_bank), GFP_KERNEL); if (!bank) { dev_err(&pdev->dev, "Memory alloc failed for gpio_bank\n"); ret = -ENOMEM; goto err_exit; } res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); if (unlikely(!res)) { dev_err(&pdev->dev, "GPIO Bank %i Invalid IRQ resource\n", pdev->id); ret = -ENODEV; goto err_free; } bank->irq = res->start; bank->id = pdev->id; pdata = pdev->dev.platform_data; bank->virtual_irq_start = pdata->virtual_irq_start; bank->dev = &pdev->dev; bank->dbck_flag = pdata->dbck_flag; bank->stride = pdata->bank_stride; bank->width = pdata->bank_width; bank->is_mpuio = pdata->is_mpuio; bank->suspend_support = pdata->suspend_support; bank->non_wakeup_gpios = pdata->non_wakeup_gpios; bank->loses_context = pdata->loses_context; bank->regs = pdata->regs; bank->saved_context = 0; if (bank->regs->set_dataout && bank->regs->clr_dataout) bank->set_dataout = _set_gpio_dataout_reg; else bank->set_dataout = _set_gpio_dataout_mask; spin_lock_init(&bank->lock); /* Static mapping, never released */ res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (unlikely(!res)) { dev_err(&pdev->dev, "GPIO Bank %i Invalid mem resource\n", pdev->id); ret = -ENODEV; goto err_free; } bank->base = ioremap(res->start, resource_size(res)); if (!bank->base) { dev_err(&pdev->dev, "Could not ioremap gpio bank%i\n", pdev->id); ret = -ENOMEM; goto err_free; } platform_set_drvdata(pdev, bank); pm_runtime_enable(bank->dev); pm_runtime_irq_safe(bank->dev); if (pm_runtime_get_sync(bank->dev) < 0) { dev_err(bank->dev, "%s: GPIO bank %d pm_runtime_get_sync " "failed\n", __func__, bank->id); iounmap(bank->base); return -EINVAL; } omap_gpio_mod_init(bank); omap_gpio_chip_init(bank); omap_gpio_show_rev(bank); if (pm_runtime_put_sync(bank->dev) < 0) { dev_err(bank->dev, "%s: GPIO bank %d pm_runtime_put_sync " "failed\n", __func__, bank->id); iounmap(bank->base); return -EINVAL; } list_add_tail(&bank->node, &omap_gpio_list); return ret; err_free: kfree(bank); err_exit: return ret; } static int omap_gpio_suspend(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct gpio_bank *bank = platform_get_drvdata(pdev); void __iomem *wake_status; void __iomem *wake_clear; void __iomem *wake_set; unsigned long flags; if (!bank->suspend_support) return 0; wake_status = bank->base + bank->regs->wkup_status; wake_clear = bank->base + bank->regs->wkup_clear; wake_set = bank->base + bank->regs->wkup_set; pm_runtime_get_sync(dev); spin_lock_irqsave(&bank->lock, flags); bank->saved_wakeup = __raw_readl(wake_status); __raw_writel(0xffffffff, wake_clear); __raw_writel(bank->suspend_wakeup, wake_set); spin_unlock_irqrestore(&bank->lock, flags); pm_runtime_put_sync(dev); return 0; } static int omap_gpio_resume(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct gpio_bank *bank = platform_get_drvdata(pdev); void __iomem *wake_clear; void __iomem *wake_set; unsigned long flags; if (!bank->suspend_support) return 0; wake_clear = bank->base + bank->regs->wkup_clear; wake_set = bank->base + bank->regs->wkup_set; pm_runtime_get_sync(dev); spin_lock_irqsave(&bank->lock, flags); __raw_writel(0xffffffff, wake_clear); __raw_writel(bank->saved_wakeup, wake_set); spin_unlock_irqrestore(&bank->lock, flags); pm_runtime_put_sync(dev); return 0; } #ifdef CONFIG_ARCH_OMAP2PLUS static void omap_gpio_save_context(struct gpio_bank *bank); static void omap_gpio_restore_context(struct gpio_bank *bank); static void omap2_gpio_set_wakeupenables(struct gpio_bank *bank, bool suspend) { unsigned long pad_wakeup; int i; bank->context.pad_set_wakeupenable = 0; if (pm_runtime_get_sync(bank->dev) < 0) { dev_err(bank->dev, "%s: GPIO bank %d pm_runtime_get_sync " "failed\n", __func__, bank->id); return; } if (suspend) pad_wakeup = bank->suspend_wakeup; else pad_wakeup = __raw_readl(bank->base + bank->regs->irqenable); /* * HACK: Ignore gpios that have multiple sources. * Gpio 0-3 and 86 are special and may be used as gpio * interrupts without being connected to the pad that * mux points to. */ if (cpu_is_omap44xx()) { if (bank->id == 0) pad_wakeup &= ~0xf; if (bank->id == 2) pad_wakeup &= ~BIT(22); } for_each_set_bit(i, &pad_wakeup, bank->width) { if (!omap_mux_get_wakeupenable(bank->mux[i])) { bank->context.pad_set_wakeupenable |= BIT(i); omap_mux_set_wakeupenable(bank->mux[i]); } } if (pm_runtime_put_sync_suspend(bank->dev) < 0) { dev_err(bank->dev, "%s: GPIO bank %d pm_runtime_put_sync " "failed\n", __func__, bank->id); return; } } static void omap2_gpio_clear_wakeupenables(struct gpio_bank *bank) { unsigned long pad_wakeup; int i; pad_wakeup = bank->context.pad_set_wakeupenable; for_each_set_bit(i, &pad_wakeup, bank->width) omap_mux_clear_wakeupenable(bank->mux[i]); } #endif static int omap_gpio_pm_runtime_suspend(struct device *dev) { #ifdef CONFIG_ARCH_OMAP2PLUS struct platform_device *pdev = to_platform_device(dev); struct gpio_bank *bank = platform_get_drvdata(pdev); u32 l1 = 0, l2 = 0; int j; /* If going to OFF, remove triggering for all * non-wakeup GPIOs. Otherwise spurious IRQs will be * generated. See OMAP2420 Errata item 1.101. */ if (!(bank->enabled_non_wakeup_gpios)) goto save_gpio_ctx; bank->saved_datain = __raw_readl(bank->base + bank->regs->datain); l1 = __raw_readl(bank->base + bank->regs->fallingdetect); l2 = __raw_readl(bank->base + bank->regs->risingdetect); bank->saved_fallingdetect = l1; bank->saved_risingdetect = l2; l1 &= ~bank->enabled_non_wakeup_gpios; l2 &= ~bank->enabled_non_wakeup_gpios; __raw_writel(l1, bank->base + bank->regs->fallingdetect); __raw_writel(l2, bank->base + bank->regs->risingdetect); save_gpio_ctx: omap_gpio_save_context(bank); for (j = 0; j < hweight_long(bank->dbck_enable_mask); j++) clk_disable(bank->dbck); #endif return 0; } static int omap_gpio_pm_runtime_resume(struct device *dev) { #ifdef CONFIG_ARCH_OMAP2PLUS struct platform_device *pdev = to_platform_device(dev); struct gpio_bank *bank = platform_get_drvdata(pdev); u32 l = 0, gen, gen0, gen1; int j; unsigned long pad_wakeup; int i; for (j = 0; j < hweight_long(bank->dbck_enable_mask); j++) clk_enable(bank->dbck); if (omap_pm_was_context_lost(dev)) omap_gpio_restore_context(bank); if (!(bank->enabled_non_wakeup_gpios)) return 0; __raw_writel(bank->saved_fallingdetect, bank->base + bank->regs->fallingdetect); __raw_writel(bank->saved_risingdetect, bank->base + bank->regs->risingdetect); l = __raw_readl(bank->base + bank->regs->datain); /* Check if any of the non-wakeup interrupt GPIOs have changed * state. If so, generate an IRQ by software. This is * horribly racy, but it's the best we can do to work around * this silicon bug. */ l ^= bank->saved_datain; l &= bank->enabled_non_wakeup_gpios; pad_wakeup = bank->enabled_non_wakeup_gpios; for_each_set_bit(i, &pad_wakeup, bank->width) if (omap_mux_get_wakeupevent(bank->mux[i])) l |= BIT(i); /* * No need to generate IRQs for the rising edge for gpio IRQs * configured with falling edge only; and vice versa. */ gen0 = l & bank->saved_fallingdetect; gen0 &= bank->saved_datain; gen1 = l & bank->saved_risingdetect; gen1 &= ~(bank->saved_datain); /* FIXME: Consider GPIO IRQs with level detections properly! */ gen = l & (~(bank->saved_fallingdetect) & ~(bank->saved_risingdetect)); /* Consider all GPIO IRQs needed to be updated */ gen |= gen0 | gen1; if (gen) { u32 old0, old1; old0 = __raw_readl(bank->base + bank->regs->leveldetect0); old1 = __raw_readl(bank->base + bank->regs->leveldetect1); __raw_writel(old0, bank->base + bank->regs->leveldetect0); __raw_writel(old1, bank->base + bank->regs->leveldetect1); if (cpu_is_omap24xx() || cpu_is_omap34xx()) { old0 |= gen; old1 |= gen; } if (cpu_is_omap44xx()) { old0 |= l; old1 |= l; } __raw_writel(old0, bank->base + bank->regs->leveldetect0); __raw_writel(old1, bank->base + bank->regs->leveldetect1); } #endif return 0; } #ifdef CONFIG_ARCH_OMAP2PLUS static int omap2_gpio_set_edge_wakeup(struct gpio_bank *bank, bool suspend) { int ret = 0; u32 wkup_status = 0; u32 datain; u32 mask; u32 active; if (pm_runtime_get_sync(bank->dev) < 0) { dev_err(bank->dev, "%s: GPIO bank %d pm_runtime_get_sync " "failed\n", __func__, bank->id); return -EINVAL; } bank->context.ew_leveldetect0 = __raw_readl(bank->base + bank->regs->leveldetect0); bank->context.ew_leveldetect1 = __raw_readl(bank->base + bank->regs->leveldetect1); wkup_status = __raw_readl(bank->base + bank->regs->wkup_status); bank->context.edge_falling = __raw_readl(bank->base + bank->regs->fallingdetect); bank->context.edge_rising = __raw_readl(bank->base + bank->regs->risingdetect); /* * Set edge trigger for all gpio's that are * expected to produce wakeup from low power. * even if they are set for level detection only. */ __raw_writel(bank->context.edge_falling | (bank->type_leveldetect0 & wkup_status), (bank->base + bank->regs->fallingdetect)); __raw_writel(bank->context.edge_rising | (bank->type_leveldetect1 & wkup_status), (bank->base + bank->regs->risingdetect)); __raw_writel(0, bank->base + bank->regs->leveldetect0); __raw_writel(0, bank->base + bank->regs->leveldetect1); /* * If a level interrupt is pending it will be lost since * we just cleared it's enable bit. Detect and abort, * the interrupt will be delivered when * omap2_gpio_restore_edge_wakeup restores the level * interrupt mask. */ datain = __raw_readl(bank->base + bank->regs->datain); if (suspend) mask = bank->suspend_wakeup; else mask = wkup_status; active = (datain & bank->type_leveldetect1 & mask) | (~datain & bank->type_leveldetect0 & mask); if (active) { if (suspend) pr_info("%s: aborted suspend due to gpio %d\n", __func__, bank->id * bank->width + __ffs(active)); ret = -EBUSY; } if (pm_runtime_put_sync_suspend(bank->dev) < 0) { dev_err(bank->dev, "%s: GPIO bank %d pm_runtime_put_sync " "failed\n", __func__, bank->id); return -EINVAL; } return ret; } static void omap2_gpio_restore_edge_wakeup(struct gpio_bank *bank) { if (pm_runtime_get_sync(bank->dev) < 0) { dev_err(bank->dev, "%s: GPIO bank %d pm_runtime_get_sync " "failed\n", __func__, bank->id); return; } __raw_writel(bank->context.edge_falling, (bank->base + bank->regs->fallingdetect)); __raw_writel(bank->context.edge_rising, (bank->base + bank->regs->risingdetect)); __raw_writel(bank->context.ew_leveldetect0, (bank->base + bank->regs->leveldetect0)); __raw_writel(bank->context.ew_leveldetect1, (bank->base + bank->regs->leveldetect1)); if (pm_runtime_put_sync_suspend(bank->dev) < 0) { dev_err(bank->dev, "%s: GPIO bank %d pm_runtime_put_sync " "failed\n", __func__, bank->id); return; } } int omap2_gpio_prepare_for_idle(int off_mode, bool suspend) { int ret = 0; struct gpio_bank *bank; list_for_each_entry(bank, &omap_gpio_list, node) { if (!bank->mod_usage) continue; omap2_gpio_set_wakeupenables(bank, suspend); if (omap2_gpio_set_edge_wakeup(bank, suspend)) ret = -EBUSY; } if (cpu_is_omap44xx()) omap4_trigger_ioctrl(); list_for_each_entry(bank, &omap_gpio_list, node) { if (!bank->mod_usage) continue; if (bank->loses_context) if (pm_runtime_put_sync_suspend(bank->dev) < 0) dev_err(bank->dev, "%s: GPIO bank %d " "pm_runtime_put_sync failed\n", __func__, bank->id); } if (ret) omap2_gpio_resume_after_idle(off_mode); return ret; } void omap2_gpio_resume_after_idle(int off_mode) { struct gpio_bank *bank; list_for_each_entry(bank, &omap_gpio_list, node) { if (!bank->mod_usage) continue; if (bank->loses_context) if (pm_runtime_get_sync(bank->dev) < 0) dev_err(bank->dev, "%s: GPIO bank %d " "pm_runtime_get_sync failed\n", __func__, bank->id); omap2_gpio_restore_edge_wakeup(bank); omap2_gpio_clear_wakeupenables(bank); } } void omap_gpio_save_context(struct gpio_bank *bank) { bank->context.irqenable1 = __raw_readl(bank->base + bank->regs->irqenable); bank->context.irqenable2 = __raw_readl(bank->base + bank->regs->irqenable2); bank->context.wake_en = __raw_readl(bank->base + bank->regs->wkup_set); bank->context.ctrl = __raw_readl(bank->base + bank->regs->ctrl); bank->context.oe = __raw_readl(bank->base + bank->regs->direction); bank->context.leveldetect0 = __raw_readl(bank->base + bank->regs->leveldetect0); bank->context.leveldetect1 = __raw_readl(bank->base + bank->regs->leveldetect1); bank->context.risingdetect = __raw_readl(bank->base + bank->regs->risingdetect); bank->context.fallingdetect = __raw_readl(bank->base + bank->regs->fallingdetect); bank->context.dataout = __raw_readl(bank->base + bank->regs->dataout); if (bank->dbck_enable_mask) { bank->context.debounce = __raw_readl(bank->base + bank->regs->debounce); bank->context.debounce_en = __raw_readl(bank->base + bank->regs->debounce_en); } bank->saved_context = 1; } void omap_gpio_restore_context(struct gpio_bank *bank) { if(!bank->saved_context) return; __raw_writel(bank->context.wake_en, bank->base + bank->regs->wkup_set); __raw_writel(bank->context.ctrl, bank->base + bank->regs->ctrl); __raw_writel(bank->context.leveldetect0, bank->base + bank->regs->leveldetect0); __raw_writel(bank->context.leveldetect1, bank->base + bank->regs->leveldetect1); __raw_writel(bank->context.risingdetect, bank->base + bank->regs->risingdetect); __raw_writel(bank->context.fallingdetect, bank->base + bank->regs->fallingdetect); if (bank->regs->set_dataout && bank->regs->clr_dataout) __raw_writel(bank->context.dataout, bank->base + bank->regs->set_dataout); else __raw_writel(bank->context.dataout, bank->base + bank->regs->dataout); __raw_writel(bank->context.oe, bank->base + bank->regs->direction); if (bank->dbck_enable_mask) { __raw_writel(bank->context.debounce, bank->base + bank->regs->debounce); __raw_writel(bank->context.debounce_en, bank->base + bank->regs->debounce_en); } __raw_writel(bank->context.irqenable1, bank->base + bank->regs->irqenable); __raw_writel(bank->context.irqenable2, bank->base + bank->regs->irqenable2); bank->saved_context = 0; } #endif static const struct dev_pm_ops gpio_pm_ops = { .runtime_suspend = omap_gpio_pm_runtime_suspend, .runtime_resume = omap_gpio_pm_runtime_resume, .suspend = omap_gpio_suspend, .resume = omap_gpio_resume, }; static struct platform_driver omap_gpio_driver = { .probe = omap_gpio_probe, .driver = { .name = "omap_gpio", .pm = &gpio_pm_ops, }, }; /* * gpio driver register needs to be done before * machine_init functions access gpio APIs. * Hence omap_gpio_drv_reg() is a postcore_initcall. */ static int __init omap_gpio_drv_reg(void) { return platform_driver_register(&omap_gpio_driver); } postcore_initcall(omap_gpio_drv_reg);