Commit ae79c190 authored by Andreas Schallenberg's avatar Andreas Schallenberg Committed by Grant Likely
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Add support for TCA6424A 



This patch extends the PCA953x driver to support TI's TCA6424A 24 bit I2C I/O expander. The patch is based on code by Michele
Bevilacqua.

Changes in v2:
- Compare ngpio against 24 in both places, not >16
- Larger datatype now u32 instead of uint.
  Bit fields not used for struct members since their address is taken.
- Be precise: TCA6424A (untested for older TCA6424)

Signed-off-by: default avatarAndreas <Schallenberg&lt;Andreas.Schallenberg@3alitytechnica.com>
Acked-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarGrant Likely <grant.likely@secretlab.ca>
parent 453007cf

drivers/gpio/gpio-pca953x.c

+30 −13
Original line number Diff line number Diff line
@@ -28,6 +28,8 @@ 
#define PCA953X_INVERT		2

#define PCA953X_DIRECTION	3



#define REG_ADDR_AI		0x80



#define PCA957X_IN		0

#define PCA957X_INVRT		1

#define PCA957X_BKEN		2
@@ -63,15 +65,15 @@ static const struct i2c_device_id pca953x_id[] = { 
	{ "pca6107", 8  | PCA953X_TYPE | PCA_INT, },

	{ "tca6408", 8  | PCA953X_TYPE | PCA_INT, },

	{ "tca6416", 16 | PCA953X_TYPE | PCA_INT, },

	/* NYET:  { "tca6424", 24, }, */

	{ "tca6424", 24 | PCA953X_TYPE | PCA_INT, },

	{ }

};

MODULE_DEVICE_TABLE(i2c, pca953x_id);



struct pca953x_chip {

	unsigned gpio_start;

	uint16_t reg_output;

	uint16_t reg_direction;

	u32 reg_output;

	u32 reg_direction;

	struct mutex i2c_lock;



#ifdef CONFIG_GPIO_PCA953X_IRQ
@@ -89,12 +91,20 @@ struct pca953x_chip { 
	int	chip_type;

};



static int pca953x_write_reg(struct pca953x_chip *chip, int reg, uint16_t val)

static int pca953x_write_reg(struct pca953x_chip *chip, int reg, u32 val)

{

	int ret = 0;



	if (chip->gpio_chip.ngpio <= 8)

		ret = i2c_smbus_write_byte_data(chip->client, reg, val);

	else if (chip->gpio_chip.ngpio == 24) {

		ret = i2c_smbus_write_word_data(chip->client,

						(reg << 2) | REG_ADDR_AI,

						val & 0xffff);

		ret = i2c_smbus_write_byte_data(chip->client,

						(reg << 2) + 2,

						(val & 0xff0000) >> 16);

	}

	else {

		switch (chip->chip_type) {

		case PCA953X_TYPE:
@@ -121,12 +131,17 @@ static int pca953x_write_reg(struct pca953x_chip *chip, int reg, uint16_t val) 
	return 0;

}



static int pca953x_read_reg(struct pca953x_chip *chip, int reg, uint16_t *val)

static int pca953x_read_reg(struct pca953x_chip *chip, int reg, u32 *val)

{

	int ret;



	if (chip->gpio_chip.ngpio <= 8)

		ret = i2c_smbus_read_byte_data(chip->client, reg);

	else if (chip->gpio_chip.ngpio == 24) {

		ret =  i2c_smbus_read_word_data(chip->client, reg << 2);

		ret |= (i2c_smbus_read_byte_data(chip->client,

						 (reg << 2) + 2)<<16);

	}

	else

		ret = i2c_smbus_read_word_data(chip->client, reg << 1);
@@ -135,14 +150,14 @@ static int pca953x_read_reg(struct pca953x_chip *chip, int reg, uint16_t *val) 
		return ret;

	}



	*val = (uint16_t)ret;

	*val = (u32)ret;

	return 0;

}



static int pca953x_gpio_direction_input(struct gpio_chip *gc, unsigned off)

{

	struct pca953x_chip *chip;

	uint16_t reg_val;

	uint reg_val;

	int ret, offset = 0;



	chip = container_of(gc, struct pca953x_chip, gpio_chip);
@@ -173,7 +188,7 @@ static int pca953x_gpio_direction_output(struct gpio_chip *gc, 
		unsigned off, int val)

{

	struct pca953x_chip *chip;

	uint16_t reg_val;

	uint reg_val;

	int ret, offset = 0;



	chip = container_of(gc, struct pca953x_chip, gpio_chip);
@@ -223,7 +238,7 @@ exit: 
static int pca953x_gpio_get_value(struct gpio_chip *gc, unsigned off)

{

	struct pca953x_chip *chip;

	uint16_t reg_val;

	u32 reg_val;

	int ret, offset = 0;



	chip = container_of(gc, struct pca953x_chip, gpio_chip);
@@ -253,7 +268,7 @@ static int pca953x_gpio_get_value(struct gpio_chip *gc, unsigned off) 
static void pca953x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)

{

	struct pca953x_chip *chip;

	uint16_t reg_val;

	u32 reg_val;

	int ret, offset = 0;



	chip = container_of(gc, struct pca953x_chip, gpio_chip);
@@ -386,7 +401,7 @@ static struct irq_chip pca953x_irq_chip = { 


static uint16_t pca953x_irq_pending(struct pca953x_chip *chip)

{

	uint16_t cur_stat;

	u32 cur_stat;

	uint16_t old_stat;

	uint16_t pending;

	uint16_t trigger;
@@ -449,6 +464,7 @@ static int pca953x_irq_setup(struct pca953x_chip *chip, 
{

	struct i2c_client *client = chip->client;

	int ret, offset = 0;

	u32 temporary;



	if (irq_base != -1

			&& (id->driver_data & PCA_INT)) {
@@ -462,7 +478,8 @@ static int pca953x_irq_setup(struct pca953x_chip *chip, 
			offset = PCA957X_IN;

			break;

		}

		ret = pca953x_read_reg(chip, offset, &chip->irq_stat);

		ret = pca953x_read_reg(chip, offset, &temporary);

		chip->irq_stat = temporary;

		if (ret)

			goto out_failed;
@@ -603,7 +620,7 @@ out: 
static int __devinit device_pca957x_init(struct pca953x_chip *chip, int invert)

{

	int ret;

	uint16_t val = 0;

	u32 val = 0;



	/* Let every port in proper state, that could save power */

	pca953x_write_reg(chip, PCA957X_PUPD, 0x0);

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