/* * 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 #define OFF_MODE 1 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; }; struct gpio_bank { struct list_head node; void __iomem *base; u16 irq; u32 non_wakeup_gpios; u32 enabled_non_wakeup_gpios; struct gpio_regs context; u32 saved_datain; u32 level_mask; u32 toggle_mask; spinlock_t lock; struct gpio_chip chip; struct clk *dbck; u32 mod_usage; u32 irq_usage; u32 dbck_enable_mask; bool dbck_enabled; struct device *dev; bool is_mpuio; bool dbck_flag; bool loses_context; bool context_valid; int stride; u32 width; int context_loss_count; int power_mode; bool workaround_enabled; void (*set_dataout)(struct gpio_bank *bank, int gpio, int enable); int (*get_context_loss_count)(struct device *dev); struct omap_gpio_reg_offs *regs; }; #define GPIO_INDEX(bank, gpio) (gpio % bank->width) #define GPIO_BIT(bank, gpio) (BIT(GPIO_INDEX(bank, gpio))) #define GPIO_MOD_CTRL_BIT BIT(0) #define BANK_USED(bank) (bank->mod_usage || bank->irq_usage) #define LINE_USED(line, offset) (line & (BIT(offset))) static int omap_irq_to_gpio(struct gpio_bank *bank, unsigned int gpio_irq) { return bank->chip.base + gpio_irq; } static inline struct gpio_bank *omap_irq_data_get_bank(struct irq_data *d) { struct gpio_chip *chip = irq_data_get_irq_chip_data(d); return container_of(chip, struct gpio_bank, chip); } static void omap_set_gpio_direction(struct gpio_bank *bank, int gpio, int is_input) { void __iomem *reg = bank->base; u32 l; reg += bank->regs->direction; l = readl_relaxed(reg); if (is_input) l |= BIT(gpio); else l &= ~(BIT(gpio)); writel_relaxed(l, reg); bank->context.oe = l; } /* set data out value using dedicate set/clear register */ static void omap_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; bank->context.dataout |= l; } else { reg += bank->regs->clr_dataout; bank->context.dataout &= ~l; } writel_relaxed(l, reg); } /* set data out value using mask register */ static void omap_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 = readl_relaxed(reg); if (enable) l |= gpio_bit; else l &= ~gpio_bit; writel_relaxed(l, reg); bank->context.dataout = l; } static int omap_get_gpio_datain(struct gpio_bank *bank, int offset) { void __iomem *reg = bank->base + bank->regs->datain; return (readl_relaxed(reg) & (BIT(offset))) != 0; } static int omap_get_gpio_dataout(struct gpio_bank *bank, int offset) { void __iomem *reg = bank->base + bank->regs->dataout; return (readl_relaxed(reg) & (BIT(offset))) != 0; } static inline void omap_gpio_rmw(void __iomem *base, u32 reg, u32 mask, bool set) { int l = readl_relaxed(base + reg); if (set) l |= mask; else l &= ~mask; writel_relaxed(l, base + reg); } static inline void omap_gpio_dbck_enable(struct gpio_bank *bank) { if (bank->dbck_enable_mask && !bank->dbck_enabled) { clk_prepare_enable(bank->dbck); bank->dbck_enabled = true; writel_relaxed(bank->dbck_enable_mask, bank->base + bank->regs->debounce_en); } } static inline void omap_gpio_dbck_disable(struct gpio_bank *bank) { if (bank->dbck_enable_mask && bank->dbck_enabled) { /* * Disable debounce before cutting it's clock. If debounce is * enabled but the clock is not, GPIO module seems to be unable * to detect events and generate interrupts at least on OMAP3. */ writel_relaxed(0, bank->base + bank->regs->debounce_en); clk_disable_unprepare(bank->dbck); bank->dbck_enabled = false; } } /** * omap2_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 omap2_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); clk_prepare_enable(bank->dbck); reg = bank->base + bank->regs->debounce; writel_relaxed(debounce, reg); reg = bank->base + bank->regs->debounce_en; val = readl_relaxed(reg); if (debounce) val |= l; else val &= ~l; bank->dbck_enable_mask = val; writel_relaxed(val, reg); clk_disable_unprepare(bank->dbck); /* * Enable debounce clock per module. * This call is mandatory because in omap_gpio_request() when * *_runtime_get_sync() is called, _gpio_dbck_enable() within * runtime callbck fails to turn on dbck because dbck_enable_mask * used within _gpio_dbck_enable() is still not initialized at * that point. Therefore we have to enable dbck here. */ omap_gpio_dbck_enable(bank); if (bank->dbck_enable_mask) { bank->context.debounce = debounce; bank->context.debounce_en = val; } } /** * omap_clear_gpio_debounce - clear debounce settings for a gpio * @bank: the gpio bank we're acting upon * @gpio: the gpio number on this @gpio * * If a gpio is using debounce, then clear the debounce enable bit and if * this is the only gpio in this bank using debounce, then clear the debounce * time too. The debounce clock will also be disabled when calling this function * if this is the only gpio in the bank using debounce. */ static void omap_clear_gpio_debounce(struct gpio_bank *bank, unsigned gpio) { u32 gpio_bit = GPIO_BIT(bank, gpio); if (!bank->dbck_flag) return; if (!(bank->dbck_enable_mask & gpio_bit)) return; bank->dbck_enable_mask &= ~gpio_bit; bank->context.debounce_en &= ~gpio_bit; writel_relaxed(bank->context.debounce_en, bank->base + bank->regs->debounce_en); if (!bank->dbck_enable_mask) { bank->context.debounce = 0; writel_relaxed(bank->context.debounce, bank->base + bank->regs->debounce); clk_disable_unprepare(bank->dbck); bank->dbck_enabled = false; } } static inline void omap_set_gpio_trigger(struct gpio_bank *bank, int gpio, unsigned trigger) { void __iomem *base = bank->base; u32 gpio_bit = BIT(gpio); omap_gpio_rmw(base, bank->regs->leveldetect0, gpio_bit, trigger & IRQ_TYPE_LEVEL_LOW); omap_gpio_rmw(base, bank->regs->leveldetect1, gpio_bit, trigger & IRQ_TYPE_LEVEL_HIGH); omap_gpio_rmw(base, bank->regs->risingdetect, gpio_bit, trigger & IRQ_TYPE_EDGE_RISING); omap_gpio_rmw(base, bank->regs->fallingdetect, gpio_bit, trigger & IRQ_TYPE_EDGE_FALLING); bank->context.leveldetect0 = readl_relaxed(bank->base + bank->regs->leveldetect0); bank->context.leveldetect1 = readl_relaxed(bank->base + bank->regs->leveldetect1); bank->context.risingdetect = readl_relaxed(bank->base + bank->regs->risingdetect); bank->context.fallingdetect = readl_relaxed(bank->base + bank->regs->fallingdetect); if (likely(!(bank->non_wakeup_gpios & gpio_bit))) { omap_gpio_rmw(base, bank->regs->wkup_en, gpio_bit, trigger != 0); bank->context.wake_en = readl_relaxed(bank->base + bank->regs->wkup_en); } /* This part needs to be executed always for OMAP{34xx, 44xx} */ if (!bank->regs->irqctrl) { /* On omap24xx proceed only when valid GPIO bit is set */ if (bank->non_wakeup_gpios) { if (!(bank->non_wakeup_gpios & gpio_bit)) goto exit; } /* * 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; } exit: bank->level_mask = readl_relaxed(bank->base + bank->regs->leveldetect0) | readl_relaxed(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 omap_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 = readl_relaxed(reg); if ((l >> gpio) & 1) l &= ~(BIT(gpio)); else l |= BIT(gpio); writel_relaxed(l, reg); } #else static void omap_toggle_gpio_edge_triggering(struct gpio_bank *bank, int gpio) {} #endif static int omap_set_gpio_triggering(struct gpio_bank *bank, int gpio, unsigned trigger) { void __iomem *reg = bank->base; void __iomem *base = bank->base; u32 l = 0; if (bank->regs->leveldetect0 && bank->regs->wkup_en) { omap_set_gpio_trigger(bank, gpio, trigger); } else if (bank->regs->irqctrl) { reg += bank->regs->irqctrl; l = readl_relaxed(reg); if ((trigger & IRQ_TYPE_SENSE_MASK) == IRQ_TYPE_EDGE_BOTH) bank->toggle_mask |= BIT(gpio); if (trigger & IRQ_TYPE_EDGE_RISING) l |= BIT(gpio); else if (trigger & IRQ_TYPE_EDGE_FALLING) l &= ~(BIT(gpio)); else return -EINVAL; writel_relaxed(l, reg); } else if (bank->regs->edgectrl1) { if (gpio & 0x08) reg += bank->regs->edgectrl2; else reg += bank->regs->edgectrl1; gpio &= 0x07; l = readl_relaxed(reg); l &= ~(3 << (gpio << 1)); if (trigger & IRQ_TYPE_EDGE_RISING) l |= 2 << (gpio << 1); if (trigger & IRQ_TYPE_EDGE_FALLING) l |= BIT(gpio << 1); /* Enable wake-up during idle for dynamic tick */ omap_gpio_rmw(base, bank->regs->wkup_en, BIT(gpio), trigger); bank->context.wake_en = readl_relaxed(bank->base + bank->regs->wkup_en); writel_relaxed(l, reg); } return 0; } static void omap_enable_gpio_module(struct gpio_bank *bank, unsigned offset) { if (bank->regs->pinctrl) { void __iomem *reg = bank->base + bank->regs->pinctrl; /* Claim the pin for MPU */ writel_relaxed(readl_relaxed(reg) | (BIT(offset)), reg); } if (bank->regs->ctrl && !BANK_USED(bank)) { void __iomem *reg = bank->base + bank->regs->ctrl; u32 ctrl; ctrl = readl_relaxed(reg); /* Module is enabled, clocks are not gated */ ctrl &= ~GPIO_MOD_CTRL_BIT; writel_relaxed(ctrl, reg); bank->context.ctrl = ctrl; } } static void omap_disable_gpio_module(struct gpio_bank *bank, unsigned offset) { void __iomem *base = bank->base; if (bank->regs->wkup_en && !LINE_USED(bank->mod_usage, offset) && !LINE_USED(bank->irq_usage, offset)) { /* Disable wake-up during idle for dynamic tick */ omap_gpio_rmw(base, bank->regs->wkup_en, BIT(offset), 0); bank->context.wake_en = readl_relaxed(bank->base + bank->regs->wkup_en); } if (bank->regs->ctrl && !BANK_USED(bank)) { void __iomem *reg = bank->base + bank->regs->ctrl; u32 ctrl; ctrl = readl_relaxed(reg); /* Module is disabled, clocks are gated */ ctrl |= GPIO_MOD_CTRL_BIT; writel_relaxed(ctrl, reg); bank->context.ctrl = ctrl; } } static int omap_gpio_is_input(struct gpio_bank *bank, int mask) { void __iomem *reg = bank->base + bank->regs->direction; return readl_relaxed(reg) & mask; } static int omap_gpio_irq_type(struct irq_data *d, unsigned type) { struct gpio_bank *bank = omap_irq_data_get_bank(d); unsigned gpio = 0; int retval; unsigned long flags; unsigned offset; if (!BANK_USED(bank)) pm_runtime_get_sync(bank->dev); #ifdef CONFIG_ARCH_OMAP1 if (d->irq > IH_MPUIO_BASE) gpio = OMAP_MPUIO(d->irq - IH_MPUIO_BASE); #endif if (!gpio) gpio = omap_irq_to_gpio(bank, d->hwirq); if (type & ~IRQ_TYPE_SENSE_MASK) return -EINVAL; if (!bank->regs->leveldetect0 && (type & (IRQ_TYPE_LEVEL_LOW|IRQ_TYPE_LEVEL_HIGH))) return -EINVAL; spin_lock_irqsave(&bank->lock, flags); offset = GPIO_INDEX(bank, gpio); retval = omap_set_gpio_triggering(bank, offset, type); if (!LINE_USED(bank->mod_usage, offset)) { omap_enable_gpio_module(bank, offset); omap_set_gpio_direction(bank, offset, 1); } else if (!omap_gpio_is_input(bank, BIT(offset))) { spin_unlock_irqrestore(&bank->lock, flags); return -EINVAL; } bank->irq_usage |= BIT(GPIO_INDEX(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 omap_clear_gpio_irqbank(struct gpio_bank *bank, int gpio_mask) { void __iomem *reg = bank->base; reg += bank->regs->irqstatus; writel_relaxed(gpio_mask, reg); /* Workaround for clearing DSP GPIO interrupts to allow retention */ if (bank->regs->irqstatus2) { reg = bank->base + bank->regs->irqstatus2; writel_relaxed(gpio_mask, reg); } /* Flush posted write for the irq status to avoid spurious interrupts */ readl_relaxed(reg); } static inline void omap_clear_gpio_irqstatus(struct gpio_bank *bank, int gpio) { omap_clear_gpio_irqbank(bank, GPIO_BIT(bank, gpio)); } static u32 omap_get_gpio_irqbank_mask(struct gpio_bank *bank) { void __iomem *reg = bank->base; u32 l; u32 mask = (BIT(bank->width)) - 1; reg += bank->regs->irqenable; l = readl_relaxed(reg); if (bank->regs->irqenable_inv) l = ~l; l &= mask; return l; } static void omap_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; bank->context.irqenable1 |= gpio_mask; } else { reg += bank->regs->irqenable; l = readl_relaxed(reg); if (bank->regs->irqenable_inv) l &= ~gpio_mask; else l |= gpio_mask; bank->context.irqenable1 = l; } writel_relaxed(l, reg); } static void omap_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; bank->context.irqenable1 &= ~gpio_mask; } else { reg += bank->regs->irqenable; l = readl_relaxed(reg); if (bank->regs->irqenable_inv) l |= gpio_mask; else l &= ~gpio_mask; bank->context.irqenable1 = l; } writel_relaxed(l, reg); } static inline void omap_set_gpio_irqenable(struct gpio_bank *bank, int gpio, int enable) { if (enable) omap_enable_gpio_irqbank(bank, GPIO_BIT(bank, gpio)); else omap_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 omap_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->context.wake_en |= gpio_bit; else bank->context.wake_en &= ~gpio_bit; writel_relaxed(bank->context.wake_en, bank->base + bank->regs->wkup_en); spin_unlock_irqrestore(&bank->lock, flags); return 0; } static void omap_reset_gpio(struct gpio_bank *bank, int gpio) { omap_set_gpio_direction(bank, GPIO_INDEX(bank, gpio), 1); omap_set_gpio_irqenable(bank, gpio, 0); omap_clear_gpio_irqstatus(bank, gpio); omap_set_gpio_triggering(bank, GPIO_INDEX(bank, gpio), IRQ_TYPE_NONE); omap_clear_gpio_debounce(bank, gpio); } /* Use disable_irq_wake() and enable_irq_wake() functions from drivers */ static int omap_gpio_wake_enable(struct irq_data *d, unsigned int enable) { struct gpio_bank *bank = omap_irq_data_get_bank(d); unsigned int gpio = omap_irq_to_gpio(bank, d->hwirq); return omap_set_gpio_wakeup(bank, gpio, enable); } 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; /* * If this is the first gpio_request for the bank, * enable the bank module. */ if (!BANK_USED(bank)) pm_runtime_get_sync(bank->dev); spin_lock_irqsave(&bank->lock, flags); /* Set trigger to none. You need to enable the desired trigger with * request_irq() or set_irq_type(). Only do this if the IRQ line has * not already been requested. */ if (!LINE_USED(bank->irq_usage, offset)) { omap_set_gpio_triggering(bank, offset, IRQ_TYPE_NONE); omap_enable_gpio_module(bank, offset); } bank->mod_usage |= BIT(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); bank->mod_usage &= ~(BIT(offset)); omap_disable_gpio_module(bank, offset); omap_reset_gpio(bank, bank->chip.base + offset); spin_unlock_irqrestore(&bank->lock, flags); /* * If this is the last gpio to be freed in the bank, * disable the bank module. */ if (!BANK_USED(bank)) pm_runtime_put(bank->dev); } /* * 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 omap_gpio_irq_handler(unsigned int irq, struct irq_desc *desc) { void __iomem *isr_reg = NULL; u32 isr; unsigned int bit; struct gpio_bank *bank; int unmasked = 0; struct irq_chip *irqchip = irq_desc_get_chip(desc); struct gpio_chip *chip = irq_get_handler_data(irq); chained_irq_enter(irqchip, desc); bank = container_of(chip, struct gpio_bank, chip); isr_reg = bank->base + bank->regs->irqstatus; pm_runtime_get_sync(bank->dev); if (WARN_ON(!isr_reg)) goto exit; while (1) { u32 isr_saved, level_mask = 0; u32 enabled; enabled = omap_get_gpio_irqbank_mask(bank); isr_saved = isr = readl_relaxed(isr_reg) & enabled; if (bank->level_mask) 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 */ omap_disable_gpio_irqbank(bank, isr_saved & ~level_mask); omap_clear_gpio_irqbank(bank, isr_saved & ~level_mask); omap_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(irqchip, desc); } if (!isr) break; while (isr) { bit = __ffs(isr); isr &= ~(BIT(bit)); /* * 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 & (BIT(bit))) omap_toggle_gpio_edge_triggering(bank, bit); generic_handle_irq(irq_find_mapping(bank->chip.irqdomain, bit)); } } /* 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(irqchip, desc); pm_runtime_put(bank->dev); } static void omap_gpio_irq_shutdown(struct irq_data *d) { struct gpio_bank *bank = omap_irq_data_get_bank(d); unsigned int gpio = omap_irq_to_gpio(bank, d->hwirq); unsigned long flags; unsigned offset = GPIO_INDEX(bank, gpio); spin_lock_irqsave(&bank->lock, flags); gpio_unlock_as_irq(&bank->chip, offset); bank->irq_usage &= ~(BIT(offset)); omap_disable_gpio_module(bank, offset); omap_reset_gpio(bank, gpio); spin_unlock_irqrestore(&bank->lock, flags); /* * If this is the last IRQ to be freed in the bank, * disable the bank module. */ if (!BANK_USED(bank)) pm_runtime_put(bank->dev); } static void omap_gpio_ack_irq(struct irq_data *d) { struct gpio_bank *bank = omap_irq_data_get_bank(d); unsigned int gpio = omap_irq_to_gpio(bank, d->hwirq); omap_clear_gpio_irqstatus(bank, gpio); } static void omap_gpio_mask_irq(struct irq_data *d) { struct gpio_bank *bank = omap_irq_data_get_bank(d); unsigned int gpio = omap_irq_to_gpio(bank, d->hwirq); unsigned long flags; spin_lock_irqsave(&bank->lock, flags); omap_set_gpio_irqenable(bank, gpio, 0); omap_set_gpio_triggering(bank, GPIO_INDEX(bank, gpio), IRQ_TYPE_NONE); spin_unlock_irqrestore(&bank->lock, flags); } static void omap_gpio_unmask_irq(struct irq_data *d) { struct gpio_bank *bank = omap_irq_data_get_bank(d); unsigned int gpio = omap_irq_to_gpio(bank, d->hwirq); 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) omap_set_gpio_triggering(bank, GPIO_INDEX(bank, gpio), trigger); /* For level-triggered GPIOs, the clearing must be done after * the HW source is cleared, thus after the handler has run */ if (bank->level_mask & irq_mask) { omap_set_gpio_irqenable(bank, gpio, 0); omap_clear_gpio_irqstatus(bank, gpio); } omap_set_gpio_irqenable(bank, gpio, 1); spin_unlock_irqrestore(&bank->lock, flags); } static struct irq_chip gpio_irq_chip = { .name = "GPIO", .irq_shutdown = omap_gpio_irq_shutdown, .irq_ack = omap_gpio_ack_irq, .irq_mask = omap_gpio_mask_irq, .irq_unmask = omap_gpio_unmask_irq, .irq_set_type = omap_gpio_irq_type, .irq_set_wake = omap_gpio_wake_enable, }; /*---------------------------------------------------------------------*/ 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); writel_relaxed(0xffff & ~bank->context.wake_en, 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); writel_relaxed(bank->context.wake_en, 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 omap_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 omap_gpio_get_direction(struct gpio_chip *chip, unsigned offset) { struct gpio_bank *bank; unsigned long flags; void __iomem *reg; int dir; bank = container_of(chip, struct gpio_bank, chip); reg = bank->base + bank->regs->direction; spin_lock_irqsave(&bank->lock, flags); dir = !!(readl_relaxed(reg) & BIT(offset)); spin_unlock_irqrestore(&bank->lock, flags); return dir; } static int omap_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); omap_set_gpio_direction(bank, offset, 1); spin_unlock_irqrestore(&bank->lock, flags); return 0; } static int omap_gpio_get(struct gpio_chip *chip, unsigned offset) { struct gpio_bank *bank; u32 mask; bank = container_of(chip, struct gpio_bank, chip); mask = (BIT(offset)); if (omap_gpio_is_input(bank, mask)) return omap_get_gpio_datain(bank, offset); else return omap_get_gpio_dataout(bank, offset); } static int omap_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); omap_set_gpio_direction(bank, offset, 0); spin_unlock_irqrestore(&bank->lock, flags); return 0; } static int omap_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); spin_lock_irqsave(&bank->lock, flags); omap2_set_gpio_debounce(bank, offset, debounce); spin_unlock_irqrestore(&bank->lock, flags); return 0; } static void omap_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 void __init omap_gpio_show_rev(struct gpio_bank *bank) { static bool called; u32 rev; if (called || bank->regs->revision == USHRT_MAX) return; rev = readw_relaxed(bank->base + bank->regs->revision); pr_info("OMAP GPIO hardware version %d.%d\n", (rev >> 4) & 0x0f, rev & 0x0f); called = true; } static void omap_gpio_mod_init(struct gpio_bank *bank) { void __iomem *base = bank->base; u32 l = 0xffffffff; if (bank->width == 16) l = 0xffff; if (bank->is_mpuio) { writel_relaxed(l, bank->base + bank->regs->irqenable); return; } omap_gpio_rmw(base, bank->regs->irqenable, l, bank->regs->irqenable_inv); omap_gpio_rmw(base, bank->regs->irqstatus, l, !bank->regs->irqenable_inv); if (bank->regs->debounce_en) writel_relaxed(0, base + bank->regs->debounce_en); /* Save OE default value (0xffffffff) in the context */ bank->context.oe = readl_relaxed(bank->base + bank->regs->direction); /* Initialize interface clk ungated, module enabled */ if (bank->regs->ctrl) writel_relaxed(0, base + bank->regs->ctrl); bank->dbck = clk_get(bank->dev, "dbclk"); if (IS_ERR(bank->dbck)) dev_err(bank->dev, "Could not get gpio dbck\n"); } static 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 = omap_gpio_irq_type; if (bank->regs->wkup_en) ct->chip.irq_set_wake = omap_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 int omap_gpio_chip_init(struct gpio_bank *bank) { int j; static int gpio; int irq_base = 0; int ret; /* * 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.get_direction = omap_gpio_get_direction; bank->chip.direction_input = omap_gpio_input; bank->chip.get = omap_gpio_get; bank->chip.direction_output = omap_gpio_output; bank->chip.set_debounce = omap_gpio_debounce; bank->chip.set = omap_gpio_set; if (bank->is_mpuio) { bank->chip.label = "mpuio"; if (bank->regs->wkup_en) 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; ret = gpiochip_add(&bank->chip); if (ret) { dev_err(bank->dev, "Could not register gpio chip %d\n", ret); return ret; } #ifdef CONFIG_ARCH_OMAP1 /* * REVISIT: Once we have OMAP1 supporting SPARSE_IRQ, we can drop * irq_alloc_descs() since a base IRQ offset will no longer be needed. */ irq_base = irq_alloc_descs(-1, 0, bank->width, 0); if (irq_base < 0) { dev_err(bank->dev, "Couldn't allocate IRQ numbers\n"); return -ENODEV; } #endif ret = gpiochip_irqchip_add(&bank->chip, &gpio_irq_chip, irq_base, omap_gpio_irq_handler, IRQ_TYPE_NONE); if (ret) { dev_err(bank->dev, "Couldn't add irqchip to gpiochip %d\n", ret); gpiochip_remove(&bank->chip); return -ENODEV; } gpiochip_set_chained_irqchip(&bank->chip, &gpio_irq_chip, bank->irq, omap_gpio_irq_handler); for (j = 0; j < bank->width; j++) { int irq = irq_find_mapping(bank->chip.irqdomain, j); if (bank->is_mpuio) { omap_mpuio_alloc_gc(bank, irq, bank->width); irq_set_chip_and_handler(irq, NULL, NULL); set_irq_flags(irq, 0); } } return 0; } static const struct of_device_id omap_gpio_match[]; static int omap_gpio_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct device_node *node = dev->of_node; const struct of_device_id *match; const struct omap_gpio_platform_data *pdata; struct resource *res; struct gpio_bank *bank; int ret; match = of_match_device(of_match_ptr(omap_gpio_match), dev); pdata = match ? match->data : dev_get_platdata(dev); if (!pdata) return -EINVAL; bank = devm_kzalloc(dev, sizeof(struct gpio_bank), GFP_KERNEL); if (!bank) { dev_err(dev, "Memory alloc failed\n"); return -ENOMEM; } res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); if (unlikely(!res)) { dev_err(dev, "Invalid IRQ resource\n"); return -ENODEV; } bank->irq = res->start; bank->dev = dev; bank->chip.dev = dev; bank->dbck_flag = pdata->dbck_flag; bank->stride = pdata->bank_stride; bank->width = pdata->bank_width; bank->is_mpuio = pdata->is_mpuio; bank->non_wakeup_gpios = pdata->non_wakeup_gpios; bank->regs = pdata->regs; #ifdef CONFIG_OF_GPIO bank->chip.of_node = of_node_get(node); #endif if (node) { if (!of_property_read_bool(node, "ti,gpio-always-on")) bank->loses_context = true; } else { bank->loses_context = pdata->loses_context; if (bank->loses_context) bank->get_context_loss_count = pdata->get_context_loss_count; } if (bank->regs->set_dataout && bank->regs->clr_dataout) bank->set_dataout = omap_set_gpio_dataout_reg; else bank->set_dataout = omap_set_gpio_dataout_mask; spin_lock_init(&bank->lock); /* Static mapping, never released */ res = platform_get_resource(pdev, IORESOURCE_MEM, 0); bank->base = devm_ioremap_resource(dev, res); if (IS_ERR(bank->base)) { irq_domain_remove(bank->chip.irqdomain); return PTR_ERR(bank->base); } platform_set_drvdata(pdev, bank); pm_runtime_enable(bank->dev); pm_runtime_irq_safe(bank->dev); pm_runtime_get_sync(bank->dev); if (bank->is_mpuio) omap_mpuio_init(bank); omap_gpio_mod_init(bank); ret = omap_gpio_chip_init(bank); if (ret) return ret; omap_gpio_show_rev(bank); pm_runtime_put(bank->dev); list_add_tail(&bank->node, &omap_gpio_list); return 0; } #ifdef CONFIG_ARCH_OMAP2PLUS #if defined(CONFIG_PM_RUNTIME) static void omap_gpio_restore_context(struct gpio_bank *bank); static int omap_gpio_runtime_suspend(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct gpio_bank *bank = platform_get_drvdata(pdev); u32 l1 = 0, l2 = 0; unsigned long flags; u32 wake_low, wake_hi; spin_lock_irqsave(&bank->lock, flags); /* * Only edges can generate a wakeup event to the PRCM. * * Therefore, ensure any wake-up capable GPIOs have * edge-detection enabled before going idle to ensure a wakeup * to the PRCM is generated on a GPIO transition. (c.f. 34xx * NDA TRM 25.5.3.1) * * The normal values will be restored upon ->runtime_resume() * by writing back the values saved in bank->context. */ wake_low = bank->context.leveldetect0 & bank->context.wake_en; if (wake_low) writel_relaxed(wake_low | bank->context.fallingdetect, bank->base + bank->regs->fallingdetect); wake_hi = bank->context.leveldetect1 & bank->context.wake_en; if (wake_hi) writel_relaxed(wake_hi | bank->context.risingdetect, bank->base + bank->regs->risingdetect); if (!bank->enabled_non_wakeup_gpios) goto update_gpio_context_count; if (bank->power_mode != OFF_MODE) { bank->power_mode = 0; goto update_gpio_context_count; } /* * If going to OFF, remove triggering for all * non-wakeup GPIOs. Otherwise spurious IRQs will be * generated. See OMAP2420 Errata item 1.101. */ bank->saved_datain = readl_relaxed(bank->base + bank->regs->datain); l1 = bank->context.fallingdetect; l2 = bank->context.risingdetect; l1 &= ~bank->enabled_non_wakeup_gpios; l2 &= ~bank->enabled_non_wakeup_gpios; writel_relaxed(l1, bank->base + bank->regs->fallingdetect); writel_relaxed(l2, bank->base + bank->regs->risingdetect); bank->workaround_enabled = true; update_gpio_context_count: if (bank->get_context_loss_count) bank->context_loss_count = bank->get_context_loss_count(bank->dev); omap_gpio_dbck_disable(bank); spin_unlock_irqrestore(&bank->lock, flags); return 0; } static void omap_gpio_init_context(struct gpio_bank *p); static int omap_gpio_runtime_resume(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct gpio_bank *bank = platform_get_drvdata(pdev); u32 l = 0, gen, gen0, gen1; unsigned long flags; int c; spin_lock_irqsave(&bank->lock, flags); /* * On the first resume during the probe, the context has not * been initialised and so initialise it now. Also initialise * the context loss count. */ if (bank->loses_context && !bank->context_valid) { omap_gpio_init_context(bank); if (bank->get_context_loss_count) bank->context_loss_count = bank->get_context_loss_count(bank->dev); } omap_gpio_dbck_enable(bank); /* * In ->runtime_suspend(), level-triggered, wakeup-enabled * GPIOs were set to edge trigger also in order to be able to * generate a PRCM wakeup. Here we restore the * pre-runtime_suspend() values for edge triggering. */ writel_relaxed(bank->context.fallingdetect, bank->base + bank->regs->fallingdetect); writel_relaxed(bank->context.risingdetect, bank->base + bank->regs->risingdetect); if (bank->loses_context) { if (!bank->get_context_loss_count) { omap_gpio_restore_context(bank); } else { c = bank->get_context_loss_count(bank->dev); if (c != bank->context_loss_count) { omap_gpio_restore_context(bank); } else { spin_unlock_irqrestore(&bank->lock, flags); return 0; } } } if (!bank->workaround_enabled) { spin_unlock_irqrestore(&bank->lock, flags); return 0; } l = readl_relaxed(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; /* * No need to generate IRQs for the rising edge for gpio IRQs * configured with falling edge only; and vice versa. */ gen0 = l & bank->context.fallingdetect; gen0 &= bank->saved_datain; gen1 = l & bank->context.risingdetect; gen1 &= ~(bank->saved_datain); /* FIXME: Consider GPIO IRQs with level detections properly! */ gen = l & (~(bank->context.fallingdetect) & ~(bank->context.risingdetect)); /* Consider all GPIO IRQs needed to be updated */ gen |= gen0 | gen1; if (gen) { u32 old0, old1; old0 = readl_relaxed(bank->base + bank->regs->leveldetect0); old1 = readl_relaxed(bank->base + bank->regs->leveldetect1); if (!bank->regs->irqstatus_raw0) { writel_relaxed(old0 | gen, bank->base + bank->regs->leveldetect0); writel_relaxed(old1 | gen, bank->base + bank->regs->leveldetect1); } if (bank->regs->irqstatus_raw0) { writel_relaxed(old0 | l, bank->base + bank->regs->leveldetect0); writel_relaxed(old1 | l, bank->base + bank->regs->leveldetect1); } writel_relaxed(old0, bank->base + bank->regs->leveldetect0); writel_relaxed(old1, bank->base + bank->regs->leveldetect1); } bank->workaround_enabled = false; spin_unlock_irqrestore(&bank->lock, flags); return 0; } #endif /* CONFIG_PM_RUNTIME */ void omap2_gpio_prepare_for_idle(int pwr_mode) { struct gpio_bank *bank; list_for_each_entry(bank, &omap_gpio_list, node) { if (!BANK_USED(bank) || !bank->loses_context) continue; bank->power_mode = pwr_mode; pm_runtime_put_sync_suspend(bank->dev); } } void omap2_gpio_resume_after_idle(void) { struct gpio_bank *bank; list_for_each_entry(bank, &omap_gpio_list, node) { if (!BANK_USED(bank) || !bank->loses_context) continue; pm_runtime_get_sync(bank->dev); } } #if defined(CONFIG_PM_RUNTIME) static void omap_gpio_init_context(struct gpio_bank *p) { struct omap_gpio_reg_offs *regs = p->regs; void __iomem *base = p->base; p->context.ctrl = readl_relaxed(base + regs->ctrl); p->context.oe = readl_relaxed(base + regs->direction); p->context.wake_en = readl_relaxed(base + regs->wkup_en); p->context.leveldetect0 = readl_relaxed(base + regs->leveldetect0); p->context.leveldetect1 = readl_relaxed(base + regs->leveldetect1); p->context.risingdetect = readl_relaxed(base + regs->risingdetect); p->context.fallingdetect = readl_relaxed(base + regs->fallingdetect); p->context.irqenable1 = readl_relaxed(base + regs->irqenable); p->context.irqenable2 = readl_relaxed(base + regs->irqenable2); if (regs->set_dataout && p->regs->clr_dataout) p->context.dataout = readl_relaxed(base + regs->set_dataout); else p->context.dataout = readl_relaxed(base + regs->dataout); p->context_valid = true; } static void omap_gpio_restore_context(struct gpio_bank *bank) { writel_relaxed(bank->context.wake_en, bank->base + bank->regs->wkup_en); writel_relaxed(bank->context.ctrl, bank->base + bank->regs->ctrl); writel_relaxed(bank->context.leveldetect0, bank->base + bank->regs->leveldetect0); writel_relaxed(bank->context.leveldetect1, bank->base + bank->regs->leveldetect1); writel_relaxed(bank->context.risingdetect, bank->base + bank->regs->risingdetect); writel_relaxed(bank->context.fallingdetect, bank->base + bank->regs->fallingdetect); if (bank->regs->set_dataout && bank->regs->clr_dataout) writel_relaxed(bank->context.dataout, bank->base + bank->regs->set_dataout); else writel_relaxed(bank->context.dataout, bank->base + bank->regs->dataout); writel_relaxed(bank->context.oe, bank->base + bank->regs->direction); if (bank->dbck_enable_mask) { writel_relaxed(bank->context.debounce, bank->base + bank->regs->debounce); writel_relaxed(bank->context.debounce_en, bank->base + bank->regs->debounce_en); } writel_relaxed(bank->context.irqenable1, bank->base + bank->regs->irqenable); writel_relaxed(bank->context.irqenable2, bank->base + bank->regs->irqenable2); } #endif /* CONFIG_PM_RUNTIME */ #else #define omap_gpio_runtime_suspend NULL #define omap_gpio_runtime_resume NULL static inline void omap_gpio_init_context(struct gpio_bank *p) {} #endif static const struct dev_pm_ops gpio_pm_ops = { SET_RUNTIME_PM_OPS(omap_gpio_runtime_suspend, omap_gpio_runtime_resume, NULL) }; #if defined(CONFIG_OF) static struct omap_gpio_reg_offs omap2_gpio_regs = { .revision = OMAP24XX_GPIO_REVISION, .direction = OMAP24XX_GPIO_OE, .datain = OMAP24XX_GPIO_DATAIN, .dataout = OMAP24XX_GPIO_DATAOUT, .set_dataout = OMAP24XX_GPIO_SETDATAOUT, .clr_dataout = OMAP24XX_GPIO_CLEARDATAOUT, .irqstatus = OMAP24XX_GPIO_IRQSTATUS1, .irqstatus2 = OMAP24XX_GPIO_IRQSTATUS2, .irqenable = OMAP24XX_GPIO_IRQENABLE1, .irqenable2 = OMAP24XX_GPIO_IRQENABLE2, .set_irqenable = OMAP24XX_GPIO_SETIRQENABLE1, .clr_irqenable = OMAP24XX_GPIO_CLEARIRQENABLE1, .debounce = OMAP24XX_GPIO_DEBOUNCE_VAL, .debounce_en = OMAP24XX_GPIO_DEBOUNCE_EN, .ctrl = OMAP24XX_GPIO_CTRL, .wkup_en = OMAP24XX_GPIO_WAKE_EN, .leveldetect0 = OMAP24XX_GPIO_LEVELDETECT0, .leveldetect1 = OMAP24XX_GPIO_LEVELDETECT1, .risingdetect = OMAP24XX_GPIO_RISINGDETECT, .fallingdetect = OMAP24XX_GPIO_FALLINGDETECT, }; static struct omap_gpio_reg_offs omap4_gpio_regs = { .revision = OMAP4_GPIO_REVISION, .direction = OMAP4_GPIO_OE, .datain = OMAP4_GPIO_DATAIN, .dataout = OMAP4_GPIO_DATAOUT, .set_dataout = OMAP4_GPIO_SETDATAOUT, .clr_dataout = OMAP4_GPIO_CLEARDATAOUT, .irqstatus = OMAP4_GPIO_IRQSTATUS0, .irqstatus2 = OMAP4_GPIO_IRQSTATUS1, .irqenable = OMAP4_GPIO_IRQSTATUSSET0, .irqenable2 = OMAP4_GPIO_IRQSTATUSSET1, .set_irqenable = OMAP4_GPIO_IRQSTATUSSET0, .clr_irqenable = OMAP4_GPIO_IRQSTATUSCLR0, .debounce = OMAP4_GPIO_DEBOUNCINGTIME, .debounce_en = OMAP4_GPIO_DEBOUNCENABLE, .ctrl = OMAP4_GPIO_CTRL, .wkup_en = OMAP4_GPIO_IRQWAKEN0, .leveldetect0 = OMAP4_GPIO_LEVELDETECT0, .leveldetect1 = OMAP4_GPIO_LEVELDETECT1, .risingdetect = OMAP4_GPIO_RISINGDETECT, .fallingdetect = OMAP4_GPIO_FALLINGDETECT, }; static const struct omap_gpio_platform_data omap2_pdata = { .regs = &omap2_gpio_regs, .bank_width = 32, .dbck_flag = false, }; static const struct omap_gpio_platform_data omap3_pdata = { .regs = &omap2_gpio_regs, .bank_width = 32, .dbck_flag = true, }; static const struct omap_gpio_platform_data omap4_pdata = { .regs = &omap4_gpio_regs, .bank_width = 32, .dbck_flag = true, }; static const struct of_device_id omap_gpio_match[] = { { .compatible = "ti,omap4-gpio", .data = &omap4_pdata, }, { .compatible = "ti,omap3-gpio", .data = &omap3_pdata, }, { .compatible = "ti,omap2-gpio", .data = &omap2_pdata, }, { }, }; MODULE_DEVICE_TABLE(of, omap_gpio_match); #endif static struct platform_driver omap_gpio_driver = { .probe = omap_gpio_probe, .driver = { .name = "omap_gpio", .pm = &gpio_pm_ops, .of_match_table = of_match_ptr(omap_gpio_match), }, }; /* * 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);