[PATCH 01/01] gpio: support pca9574 and pca9575

From: Haojian Zhuang
Date: Mon Apr 18 2011 - 10:18:22 EST


PCA957x is i2c gpio expander, and similar to PCA953x. Although register
configurations are different between PCA957x and PCA953x. They can share
a lot of components, such as IRQ handling, GPIO IN/OUT. So updating PCA953x
driver to support PCA957x chips.

Signed-off-by: Haojian Zhuang <haojian.zhuang@xxxxxxxxxxx>
Cc: Grant Likely <grant.likely@xxxxxxxxxxxx>
---
drivers/gpio/pca953x.c | 249 +++++++++++++++++++++++++++++++++++++-----------
1 files changed, 191 insertions(+), 58 deletions(-)

diff --git a/drivers/gpio/pca953x.c b/drivers/gpio/pca953x.c
index b473429..0de208f 100644
--- a/drivers/gpio/pca953x.c
+++ b/drivers/gpio/pca953x.c
@@ -24,33 +24,46 @@
#include <linux/of_gpio.h>
#endif

-#define PCA953X_INPUT 0
-#define PCA953X_OUTPUT 1
-#define PCA953X_INVERT 2
-#define PCA953X_DIRECTION 3
-
-#define PCA953X_GPIOS 0x00FF
-#define PCA953X_INT 0x0100
+#define PCA953X_INPUT 0
+#define PCA953X_OUTPUT 1
+#define PCA953X_INVERT 2
+#define PCA953X_DIRECTION 3
+
+#define PCA957X_IN 0
+#define PCA957X_INVRT 1
+#define PCA957X_BKEN 2
+#define PCA957X_PUPD 3
+#define PCA957X_CFG 4
+#define PCA957X_OUT 5
+#define PCA957X_MSK 6
+#define PCA957X_INTS 7
+
+#define PCA_GPIO_MASK 0x00FF
+#define PCA_INT 0x0100
+#define PCA953X_TYPE 0x1000
+#define PCA957X_TYPE 0x2000

static const struct i2c_device_id pca953x_id[] = {
- { "pca9534", 8 | PCA953X_INT, },
- { "pca9535", 16 | PCA953X_INT, },
- { "pca9536", 4, },
- { "pca9537", 4 | PCA953X_INT, },
- { "pca9538", 8 | PCA953X_INT, },
- { "pca9539", 16 | PCA953X_INT, },
- { "pca9554", 8 | PCA953X_INT, },
- { "pca9555", 16 | PCA953X_INT, },
- { "pca9556", 8, },
- { "pca9557", 8, },
-
- { "max7310", 8, },
- { "max7312", 16 | PCA953X_INT, },
- { "max7313", 16 | PCA953X_INT, },
- { "max7315", 8 | PCA953X_INT, },
- { "pca6107", 8 | PCA953X_INT, },
- { "tca6408", 8 | PCA953X_INT, },
- { "tca6416", 16 | PCA953X_INT, },
+ { "pca9534", 8 | PCA953X_TYPE | PCA_INT, },
+ { "pca9535", 16 | PCA953X_TYPE | PCA_INT, },
+ { "pca9536", 4 | PCA953X_TYPE, },
+ { "pca9537", 4 | PCA953X_TYPE | PCA_INT, },
+ { "pca9538", 8 | PCA953X_TYPE | PCA_INT, },
+ { "pca9539", 16 | PCA953X_TYPE | PCA_INT, },
+ { "pca9554", 8 | PCA953X_TYPE | PCA_INT, },
+ { "pca9555", 16 | PCA953X_TYPE | PCA_INT, },
+ { "pca9556", 8 | PCA953X_TYPE, },
+ { "pca9557", 8 | PCA953X_TYPE, },
+ { "pca9574", 8 | PCA957X_TYPE | PCA_INT, },
+ { "pca9575", 16 | PCA957X_TYPE | PCA_INT, },
+
+ { "max7310", 8 | PCA953X_TYPE, },
+ { "max7312", 16 | PCA953X_TYPE | PCA_INT, },
+ { "max7313", 16 | PCA953X_TYPE | PCA_INT, },
+ { "max7315", 8 | PCA953X_TYPE | PCA_INT, },
+ { "pca6107", 8 | PCA953X_TYPE | PCA_INT, },
+ { "tca6408", 8 | PCA953X_TYPE | PCA_INT, },
+ { "tca6416", 16 | PCA953X_TYPE | PCA_INT, },
/* NYET: { "tca6424", 24, }, */
{ }
};
@@ -75,16 +88,32 @@ struct pca953x_chip {
struct pca953x_platform_data *dyn_pdata;
struct gpio_chip gpio_chip;
const char *const *names;
+ int chip_type;
};

static int pca953x_write_reg(struct pca953x_chip *chip, int reg, uint16_t val)
{
- int ret;
+ int ret = 0;

if (chip->gpio_chip.ngpio <= 8)
ret = i2c_smbus_write_byte_data(chip->client, reg, val);
- else
- ret = i2c_smbus_write_word_data(chip->client, reg << 1, val);
+ else {
+ switch (chip->chip_type) {
+ case PCA953X_TYPE:
+ ret = i2c_smbus_write_word_data(chip->client,
+ reg << 1, val);
+ break;
+ case PCA957X_TYPE:
+ ret = i2c_smbus_write_byte_data(chip->client, reg << 1,
+ val & 0xff);
+ if (ret < 0)
+ break;
+ ret = i2c_smbus_write_byte_data(chip->client,
+ (reg << 1) + 1,
+ (val & 0xff00) >> 8);
+ break;
+ }
+ }

if (ret < 0) {
dev_err(&chip->client->dev, "failed writing register\n");
@@ -116,13 +145,22 @@ static int pca953x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
{
struct pca953x_chip *chip;
uint16_t reg_val;
- int ret;
+ int ret, offset = 0;

chip = container_of(gc, struct pca953x_chip, gpio_chip);

mutex_lock(&chip->i2c_lock);
reg_val = chip->reg_direction | (1u << off);
- ret = pca953x_write_reg(chip, PCA953X_DIRECTION, reg_val);
+
+ switch (chip->chip_type) {
+ case PCA953X_TYPE:
+ offset = PCA953X_DIRECTION;
+ break;
+ case PCA957X_TYPE:
+ offset = PCA957X_CFG;
+ break;
+ }
+ ret = pca953x_write_reg(chip, offset, reg_val);
if (ret)
goto exit;

@@ -138,7 +176,7 @@ static int pca953x_gpio_direction_output(struct gpio_chip *gc,
{
struct pca953x_chip *chip;
uint16_t reg_val;
- int ret;
+ int ret, offset = 0;

chip = container_of(gc, struct pca953x_chip, gpio_chip);

@@ -149,7 +187,15 @@ static int pca953x_gpio_direction_output(struct gpio_chip *gc,
else
reg_val = chip->reg_output & ~(1u << off);

- ret = pca953x_write_reg(chip, PCA953X_OUTPUT, reg_val);
+ switch (chip->chip_type) {
+ case PCA953X_TYPE:
+ offset = PCA953X_OUTPUT;
+ break;
+ case PCA957X_TYPE:
+ offset = PCA957X_OUT;
+ break;
+ }
+ ret = pca953x_write_reg(chip, offset, reg_val);
if (ret)
goto exit;

@@ -157,7 +203,15 @@ static int pca953x_gpio_direction_output(struct gpio_chip *gc,

/* then direction */
reg_val = chip->reg_direction & ~(1u << off);
- ret = pca953x_write_reg(chip, PCA953X_DIRECTION, reg_val);
+ switch (chip->chip_type) {
+ case PCA953X_TYPE:
+ offset = PCA953X_DIRECTION;
+ break;
+ case PCA957X_TYPE:
+ offset = PCA957X_CFG;
+ break;
+ }
+ ret = pca953x_write_reg(chip, offset, reg_val);
if (ret)
goto exit;

@@ -172,12 +226,20 @@ static int pca953x_gpio_get_value(struct gpio_chip *gc, unsigned off)
{
struct pca953x_chip *chip;
uint16_t reg_val;
- int ret;
+ int ret, offset = 0;

chip = container_of(gc, struct pca953x_chip, gpio_chip);

mutex_lock(&chip->i2c_lock);
- ret = pca953x_read_reg(chip, PCA953X_INPUT, &reg_val);
+ switch (chip->chip_type) {
+ case PCA953X_TYPE:
+ offset = PCA953X_INPUT;
+ break;
+ case PCA957X_TYPE:
+ offset = PCA957X_IN;
+ break;
+ }
+ ret = pca953x_read_reg(chip, offset, &reg_val);
mutex_unlock(&chip->i2c_lock);
if (ret < 0) {
/* NOTE: diagnostic already emitted; that's all we should
@@ -194,7 +256,7 @@ static void pca953x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
{
struct pca953x_chip *chip;
uint16_t reg_val;
- int ret;
+ int ret, offset = 0;

chip = container_of(gc, struct pca953x_chip, gpio_chip);

@@ -204,7 +266,15 @@ static void pca953x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
else
reg_val = chip->reg_output & ~(1u << off);

- ret = pca953x_write_reg(chip, PCA953X_OUTPUT, reg_val);
+ switch (chip->chip_type) {
+ case PCA953X_TYPE:
+ offset = PCA953X_OUTPUT;
+ break;
+ case PCA957X_TYPE:
+ offset = PCA957X_OUT;
+ break;
+ }
+ ret = pca953x_write_reg(chip, offset, reg_val);
if (ret)
goto exit;

@@ -322,9 +392,17 @@ static uint16_t pca953x_irq_pending(struct pca953x_chip *chip)
uint16_t old_stat;
uint16_t pending;
uint16_t trigger;
- int ret;
-
- ret = pca953x_read_reg(chip, PCA953X_INPUT, &cur_stat);
+ int ret, offset = 0;
+
+ switch (chip->chip_type) {
+ case PCA953X_TYPE:
+ offset = PCA953X_INPUT;
+ break;
+ case PCA957X_TYPE:
+ offset = PCA957X_IN;
+ break;
+ }
+ ret = pca953x_read_reg(chip, offset, &cur_stat);
if (ret)
return 0;

@@ -372,14 +450,21 @@ static int pca953x_irq_setup(struct pca953x_chip *chip,
{
struct i2c_client *client = chip->client;
struct pca953x_platform_data *pdata = client->dev.platform_data;
- int ret;
+ int ret, offset = 0;

if (pdata->irq_base != -1
- && (id->driver_data & PCA953X_INT)) {
+ && (id->driver_data & PCA_INT)) {
int lvl;

- ret = pca953x_read_reg(chip, PCA953X_INPUT,
- &chip->irq_stat);
+ switch (chip->chip_type) {
+ case PCA953X_TYPE:
+ offset = PCA953X_INPUT;
+ break;
+ case PCA957X_TYPE:
+ offset = PCA957X_IN;
+ break;
+ }
+ ret = pca953x_read_reg(chip, offset, &chip->irq_stat);
if (ret)
goto out_failed;

@@ -439,7 +524,7 @@ static int pca953x_irq_setup(struct pca953x_chip *chip,
struct i2c_client *client = chip->client;
struct pca953x_platform_data *pdata = client->dev.platform_data;

- if (pdata->irq_base != -1 && (id->driver_data & PCA953X_INT))
+ if (pdata->irq_base != -1 && (id->driver_data & PCA_INT))
dev_warn(&client->dev, "interrupt support not compiled in\n");

return 0;
@@ -498,12 +583,65 @@ pca953x_get_alt_pdata(struct i2c_client *client)
}
#endif

+static int __devinit device_pca953x_init(struct pca953x_chip *chip, int invert)
+{
+ int ret;
+
+ ret = pca953x_read_reg(chip, PCA953X_OUTPUT, &chip->reg_output);
+ if (ret)
+ goto out;
+
+ ret = pca953x_read_reg(chip, PCA953X_DIRECTION,
+ &chip->reg_direction);
+ if (ret)
+ goto out;
+
+ /* set platform specific polarity inversion */
+ ret = pca953x_write_reg(chip, PCA953X_INVERT, invert);
+ if (ret)
+ goto out;
+ return 0;
+out:
+ return ret;
+}
+
+static int __devinit device_pca957x_init(struct pca953x_chip *chip, int invert)
+{
+ int ret;
+ uint16_t val = 0;
+
+ /* Let every port in proper state, that could save power */
+ pca953x_write_reg(chip, PCA957X_PUPD, 0x0);
+ pca953x_write_reg(chip, PCA957X_CFG, 0xffff);
+ pca953x_write_reg(chip, PCA957X_OUT, 0x0);
+
+ ret = pca953x_read_reg(chip, PCA957X_IN, &val);
+ if (ret)
+ goto out;
+ ret = pca953x_read_reg(chip, PCA957X_OUT, &chip->reg_output);
+ if (ret)
+ goto out;
+ ret = pca953x_read_reg(chip, PCA957X_CFG, &chip->reg_direction);
+ if (ret)
+ goto out;
+
+ /* set platform specific polarity inversion */
+ pca953x_write_reg(chip, PCA957X_INVRT, invert);
+
+ /* To enable register 6, 7 to controll pull up and pull down */
+ pca953x_write_reg(chip, PCA957X_BKEN, 0x202);
+
+ return 0;
+out:
+ return ret;
+}
+
static int __devinit pca953x_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct pca953x_platform_data *pdata;
struct pca953x_chip *chip;
- int ret;
+ int ret = 0;

chip = kzalloc(sizeof(struct pca953x_chip), GFP_KERNEL);
if (chip == NULL)
@@ -530,25 +668,20 @@ static int __devinit pca953x_probe(struct i2c_client *client,
chip->gpio_start = pdata->gpio_base;

chip->names = pdata->names;
+ chip->chip_type = id->driver_data & (PCA953X_TYPE | PCA957X_TYPE);

mutex_init(&chip->i2c_lock);

/* initialize cached registers from their original values.
* we can't share this chip with another i2c master.
*/
- pca953x_setup_gpio(chip, id->driver_data & PCA953X_GPIOS);
+ pca953x_setup_gpio(chip, id->driver_data & PCA_GPIO_MASK);

- ret = pca953x_read_reg(chip, PCA953X_OUTPUT, &chip->reg_output);
- if (ret)
- goto out_failed;
-
- ret = pca953x_read_reg(chip, PCA953X_DIRECTION, &chip->reg_direction);
- if (ret)
- goto out_failed;
-
- /* set platform specific polarity inversion */
- ret = pca953x_write_reg(chip, PCA953X_INVERT, pdata->invert);
- if (ret)
+ if (chip->chip_type == PCA953X_TYPE)
+ device_pca953x_init(chip, pdata->invert);
+ else if (chip->chip_type == PCA957X_TYPE)
+ device_pca957x_init(chip, pdata->invert);
+ else
goto out_failed;

ret = pca953x_irq_setup(chip, id);
--
1.5.6.5

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