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Subject[PATCH v2] Add support for TCA6424A
Date
From 3fcb45bad283740a48c17ff078c28dd1354204ae Mon Sep 17 00:00:00 2001
From: Andreas Schallenberg <Andreas.Schallenberg@3alitytechnica.com>
Date: Wed, 25 Apr 2012 14:51:30 +0200
Subject: [PATCH] Add support for TCA6424A

This patch extends the PCA953x driver to support TI's TCA6424A 24 bit I2C I/O expander.
The patch is 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)

Should the chip name string read tca6424a as well?

Signed-off-by: Andreas Schallenberg<Andreas.Schallenberg@3alitytechnica.com>

---
drivers/gpio/gpio-pca953x.c | 43 ++++++++++++++++++++++++++++++-------------
1 files changed, 30 insertions(+), 13 deletions(-)
diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index d3f3e8f..bef3cb1 100644
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -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);
--
1.7.3.4
--
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