path: root/drivers/gpio/gpio-omap.c

/*
 * Support functions for OMAP GPIO
 *
 * Copyright (C) 2003-2005 Nokia Corporation
 * Written by Juha Yrjölä <juha.yrjola@nokia.com>
 *
 * Copyright (C) 2009 Texas Instruments
 * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
 *
 * 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 <linux/init.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/syscore_ops.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/device.h>
#include <linux/pm_runtime.h>
#include <linux/pm.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/irqdomain.h>
#include <linux/gpio.h>
#include <linux/platform_data/gpio-omap.h>

#include <asm/mach/irq.h>

#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;
	int irq_base;
	struct irq_domain *domain;
	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 dbck_enable_mask;
	bool dbck_enabled;
	struct device *dev;
	bool is_mpuio;
	bool dbck_flag;
	bool loses_context;
	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) (1 << GPIO_INDEX(bank, gpio))
#define GPIO_MOD_CTRL_BIT	BIT(0)

static int irq_to_gpio(struct gpio_bank *bank, unsigned int gpio_irq)
{
	return gpio_irq - bank->irq_base + bank->chip.base;
}

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);
	bank->context.oe = l;
}


/* 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;
		bank->context.dataout |= l;
	} else {
		reg += bank->regs->clr_dataout;
		bank->context.dataout &= ~l;
	}

	__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);
	bank->context.dataout = l;
}

static int _get_gpio_datain(struct gpio_bank *bank, int offset)
{
	void __iomem *reg = bank->base + bank->regs->datain;

	return (__raw_readl(reg) & (1 << offset)) != 0;
}

static int _get_gpio_dataout(struct gpio_bank *bank, int offset)
{
	void __iomem *reg = bank->base + bank->regs->dataout;

	return (__raw_readl(reg) & (1 << offset)) != 0;
}

static inline void _gpio_rmw(void __iomem *base, u32 reg, u32 mask, bool set)
{
	int l = __raw_readl(base + reg);

	if (set)
		l |= mask;
	else
		l &= ~mask;

	__raw_writel(l, base + reg);
}

static inline void _gpio_dbck_enable(struct gpio_bank *bank)
{
	if (bank->dbck_enable_mask && !bank->dbck_enabled) {
		clk_enable(bank->dbck);
		bank->dbck_enabled = true;

		__raw_writel(bank->dbck_enable_mask,
			     bank->base + bank->regs->debounce_en);
	}
}

static inline void _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.
		 */
		__raw_writel(0, bank->base + bank->regs->debounce_en);

		clk_disable(bank->dbck);
		bank->dbck_enabled = false;
	}
}

/**
 * _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);

	clk_enable(bank->dbck);
	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;
	else
		val &= ~l;
	bank->dbck_enable_mask = val;

	__raw_writel(val, reg);
	clk_disable(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.
	 */
	_gpio_dbck_enable(bank);
	if (bank->dbck_enable_mask) {
		bank->context.debounce = debounce;
		bank->context.debounce_en = val;
	}
}

/**
 * _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 _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;
	__raw_writel(bank->context.debounce_en,
		     bank->base + bank->regs->debounce_en);

	if (!bank->dbck_enable_mask) {
		bank->context.debounce = 0;
		__raw_writel(bank->context.debounce, bank->base +
			     bank->regs->debounce);
		clk_disable(bank->dbck);
		bank->dbck_enabled = false;
	}
}

static inline void set_gpio_trigger(struct gpio_bank *bank, int gpio,
						unsigned trigger)
{
	void __iomem *base = bank->base;
	u32 gpio_bit = 1 << gpio;

	_gpio_rmw(base, bank->regs->leveldetect0, gpio_bit,
		  trigger & IRQ_TYPE_LEVEL_LOW);
	_gpio_r