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Commit 0fc64cc0 authored by Magnus Damm's avatar Magnus Damm Committed by Paul Mundt
Browse files

sh: lockless gpio_get_value() 



This patch separates the register read and write functions to
allow lockless gpio_get_value().

Signed-off-by: default avatarMagnus Damm <damm@igel.co.jp>
Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent 18801be7

arch/sh/kernel/gpio.c

+63 −63
Original line number Diff line number Diff line
@@ -46,9 +46,8 @@ static int enum_in_range(pinmux_enum_t enum_id, struct pinmux_range *r) 
	return 1;

}



static int read_write_reg(unsigned long reg, unsigned long reg_width,

			  unsigned long field_width, unsigned long in_pos,

			  unsigned long value, int do_write)

static int gpio_read_reg(unsigned long reg, unsigned long reg_width,

			 unsigned long field_width, unsigned long in_pos)

{

	unsigned long data, mask, pos;
@@ -57,10 +56,9 @@ static int read_write_reg(unsigned long reg, unsigned long reg_width, 
	pos = reg_width - ((in_pos + 1) * field_width);



#ifdef DEBUG

	pr_info("%s, addr = %lx, value = %ld, pos = %ld, "

	pr_info("read_reg: addr = %lx, pos = %ld, "

		"r_width = %ld, f_width = %ld\n",

		do_write ? "write" : "read", reg, value, pos,

		reg_width, field_width);

		reg, pos, reg_width, field_width);

#endif



	switch (reg_width) {
@@ -75,24 +73,38 @@ static int read_write_reg(unsigned long reg, unsigned long reg_width, 
		break;

	}



	if (!do_write)

	return (data >> pos) & mask;

}



	data &= ~(mask << pos);

	data |= value << pos;

static void gpio_write_reg(unsigned long reg, unsigned long reg_width,

			   unsigned long field_width, unsigned long in_pos,

			   unsigned long value)

{

	unsigned long mask, pos;



	mask = (1 << field_width) - 1;

	pos = reg_width - ((in_pos + 1) * field_width);



#ifdef DEBUG

	pr_info("write_reg addr = %lx, value = %ld, pos = %ld, "

		"r_width = %ld, f_width = %ld\n",

		reg, value, pos, reg_width, field_width);

#endif



	mask = ~(mask << pos);

	value = value << pos;



	switch (reg_width) {

	case 8:

		ctrl_outb(data, reg);

		ctrl_outb((ctrl_inb(reg) & mask) | value, reg);

		break;

	case 16:

		ctrl_outw(data, reg);

		ctrl_outw((ctrl_inw(reg) & mask) | value, reg);

		break;

	case 32:

		ctrl_outl(data, reg);

		ctrl_outl((ctrl_inl(reg) & mask) | value, reg);

		break;

	}

	return 0;

}



static int setup_data_reg(struct pinmux_info *gpioc, unsigned gpio)
@@ -205,7 +217,7 @@ static int get_gpio_enum_id(struct pinmux_info *gpioc, unsigned gpio, 
	return -1;

}



static int write_config_reg(struct pinmux_info *gpioc,

static void write_config_reg(struct pinmux_info *gpioc,

			     struct pinmux_cfg_reg *crp,

			     int index)

{
@@ -215,8 +227,7 @@ static int write_config_reg(struct pinmux_info *gpioc, 
	pos = index / ncomb;

	value = index % ncomb;



	return read_write_reg(crp->reg, crp->reg_width,

			      crp->field_width, pos, value, 1);

	gpio_write_reg(crp->reg, crp->reg_width, crp->field_width, pos, value);

}



static int check_config_reg(struct pinmux_info *gpioc,
@@ -229,8 +240,8 @@ static int check_config_reg(struct pinmux_info *gpioc, 
	pos = index / ncomb;

	value = index % ncomb;



	if (read_write_reg(crp->reg, crp->reg_width,

			   crp->field_width, pos, 0, 0) == value)

	if (gpio_read_reg(crp->reg, crp->reg_width,

			  crp->field_width, pos) == value)

		return 0;



	return -1;
@@ -238,7 +249,7 @@ static int check_config_reg(struct pinmux_info *gpioc, 


enum { GPIO_CFG_DRYRUN, GPIO_CFG_REQ, GPIO_CFG_FREE };



int pinmux_config_gpio(struct pinmux_info *gpioc, unsigned gpio,

static int pinmux_config_gpio(struct pinmux_info *gpioc, unsigned gpio,

			      int pinmux_type, int cfg_mode)

{

	struct pinmux_cfg_reg *cr = NULL;
@@ -305,8 +316,7 @@ int pinmux_config_gpio(struct pinmux_info *gpioc, unsigned gpio, 
			break;



		case GPIO_CFG_REQ:

			if (write_config_reg(gpioc, cr, index) != 0)

				goto out_err;

			write_config_reg(gpioc, cr, index);

			*cntp = *cntp + 1;

			break;
@@ -393,9 +403,12 @@ EXPORT_SYMBOL(gpio_free); 
static int pinmux_direction(struct pinmux_info *gpioc,

			    unsigned gpio, int new_pinmux_type)

{

	int ret, pinmux_type;

	int pinmux_type;

	int ret = -EINVAL;



	if (!gpioc)

		goto err_out;



	ret = -EINVAL;

	pinmux_type = gpioc->gpios[gpio].flags & PINMUX_FLAG_TYPE;



	switch (pinmux_type) {
@@ -433,68 +446,59 @@ int gpio_direction_input(unsigned gpio) 
{

	struct pinmux_info *gpioc = gpio_controller(gpio);

	unsigned long flags;

	int ret = -EINVAL;



	if (!gpioc)

		goto err_out;

	int ret;



	spin_lock_irqsave(&gpio_lock, flags);

	ret = pinmux_direction(gpioc, gpio, PINMUX_TYPE_INPUT);

	spin_unlock_irqrestore(&gpio_lock, flags);

 err_out:



	return ret;

}

EXPORT_SYMBOL(gpio_direction_input);



static int __gpio_get_set_value(struct pinmux_info *gpioc,

				unsigned gpio, int value,

				int do_write)

static void __gpio_set_value(struct pinmux_info *gpioc,

			     unsigned gpio, int value)

{

	struct pinmux_data_reg *dr = NULL;

	int bit = 0;



	if (get_data_reg(gpioc, gpio, &dr, &bit) != 0)

	if (!gpioc || get_data_reg(gpioc, gpio, &dr, &bit) != 0)

		BUG();

	else

		value = read_write_reg(dr->reg, dr->reg_width,

				       1, bit, !!value, do_write);



	return value;

		gpio_write_reg(dr->reg, dr->reg_width, 1, bit, !!value);

}



int gpio_direction_output(unsigned gpio, int value)

{

	struct pinmux_info *gpioc = gpio_controller(gpio);

	unsigned long flags;

	int ret = -EINVAL;



	if (!gpioc)

		goto err_out;

	int ret;



	spin_lock_irqsave(&gpio_lock, flags);

	__gpio_get_set_value(gpioc, gpio, value, 1);

	__gpio_set_value(gpioc, gpio, value);

	ret = pinmux_direction(gpioc, gpio, PINMUX_TYPE_OUTPUT);

	spin_unlock_irqrestore(&gpio_lock, flags);

 err_out:



	return ret;

}

EXPORT_SYMBOL(gpio_direction_output);



int gpio_get_value(unsigned gpio)

static int __gpio_get_value(struct pinmux_info *gpioc, unsigned gpio)

{

	struct pinmux_info *gpioc = gpio_controller(gpio);

	unsigned long flags;

	int value = 0;

	struct pinmux_data_reg *dr = NULL;

	int bit = 0;



	if (!gpioc)

	if (!gpioc || get_data_reg(gpioc, gpio, &dr, &bit) != 0) {

		BUG();

	else {

		spin_lock_irqsave(&gpio_lock, flags);

		value = __gpio_get_set_value(gpioc, gpio, 0, 0);

		spin_unlock_irqrestore(&gpio_lock, flags);

		return 0;

	}



	return gpio_read_reg(dr->reg, dr->reg_width, 1, bit);

}



	return value;

int gpio_get_value(unsigned gpio)

{

	return __gpio_get_value(gpio_controller(gpio), gpio);

}

EXPORT_SYMBOL(gpio_get_value);
@@ -503,14 +507,10 @@ void gpio_set_value(unsigned gpio, int value) 
	struct pinmux_info *gpioc = gpio_controller(gpio);

	unsigned long flags;



	if (!gpioc)

		BUG();

	else {

	spin_lock_irqsave(&gpio_lock, flags);

		__gpio_get_set_value(gpioc, gpio, value, 1);

	__gpio_set_value(gpioc, gpio, value);

	spin_unlock_irqrestore(&gpio_lock, flags);

}

}

EXPORT_SYMBOL(gpio_set_value);



int register_pinmux(struct pinmux_info *pip)