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Add support for TCA6424A
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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: Andreas Schallenberg<Andreas.Schallenberg@3alitytechnica.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
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Andreas Schallenberg authored and Grant Likely committed May 18, 2012
1 parent 453007c commit ae79c19
Showing 1 changed file with 30 additions and 13 deletions.
43 changes: 30 additions & 13 deletions drivers/gpio/gpio-pca953x.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand Down Expand Up @@ -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
Expand All @@ -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:
Expand All @@ -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);

Expand All @@ -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);
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -223,7 +238,7 @@ static int pca953x_gpio_direction_output(struct gpio_chip *gc,
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);
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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)) {
Expand All @@ -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;

Expand Down Expand Up @@ -603,7 +620,7 @@ static int __devinit device_pca953x_init(struct pca953x_chip *chip, int invert)
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);
Expand Down

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