[PATCH v4 1/5] gpio: pca953x: code shrink

From: Bartosz Golaszewski
Date: Wed Sep 07 2016 - 10:52:47 EST

There are multiple places in the driver code where a
switch (chip->chip_type) is used to determine the proper register
offset.

Unduplicate the code by adding a simple structure holding the possible
offsets that differ between the pca953x and pca957x chip families and
use it to avoid the checks.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/gpio/gpio-pca953x.c | 122 +++++++++++++++-----------------------------
1 file changed, 42 insertions(+), 80 deletions(-)

diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index 02f2a56..d47e6f9 100644
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -94,6 +94,24 @@ MODULE_DEVICE_TABLE(acpi, pca953x_acpi_ids);

#define NBANK(chip) DIV_ROUND_UP(chip->gpio_chip.ngpio, BANK_SZ)

+struct pca953x_offset {
+ int direction;
+ int output;
+ int input;
+};
+
+static const struct pca953x_offset pca953x_offsets = {
+ .direction = PCA953X_DIRECTION,
+ .output = PCA953X_OUTPUT,
+ .input = PCA953X_INPUT,
+};
+
+static const struct pca953x_offset pca957x_offsets = {
+ .direction = PCA957X_CFG,
+ .output = PCA957X_OUT,
+ .input = PCA957X_IN,
+};
+
struct pca953x_chip {
unsigned gpio_start;
u8 reg_output[MAX_BANK];
@@ -113,6 +131,8 @@ struct pca953x_chip {
const char *const *names;
int chip_type;
unsigned long driver_data;
+
+ const struct pca953x_offset *offset;
};

static int pca953x_read_single(struct pca953x_chip *chip, int reg, u32 *val,
@@ -222,20 +242,12 @@ static int pca953x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
{
struct pca953x_chip *chip = gpiochip_get_data(gc);
u8 reg_val;
- int ret, offset = 0;
+ int ret;

mutex_lock(&chip->i2c_lock);
reg_val = chip->reg_direction[off / BANK_SZ] | (1u << (off % BANK_SZ));

- switch (chip->chip_type) {
- case PCA953X_TYPE:
- offset = PCA953X_DIRECTION;
- break;
- case PCA957X_TYPE:
- offset = PCA957X_CFG;
- break;
- }
- ret = pca953x_write_single(chip, offset, reg_val, off);
+ ret = pca953x_write_single(chip, chip->offset->direction, reg_val, off);
if (ret)
goto exit;

@@ -250,7 +262,7 @@ static int pca953x_gpio_direction_output(struct gpio_chip *gc,
{
struct pca953x_chip *chip = gpiochip_get_data(gc);
u8 reg_val;
- int ret, offset = 0;
+ int ret;

mutex_lock(&chip->i2c_lock);
/* set output level */
@@ -261,15 +273,7 @@ static int pca953x_gpio_direction_output(struct gpio_chip *gc,
reg_val = chip->reg_output[off / BANK_SZ]
& ~(1u << (off % BANK_SZ));

- switch (chip->chip_type) {
- case PCA953X_TYPE:
- offset = PCA953X_OUTPUT;
- break;
- case PCA957X_TYPE:
- offset = PCA957X_OUT;
- break;
- }
- ret = pca953x_write_single(chip, offset, reg_val, off);
+ ret = pca953x_write_single(chip, chip->offset->output, reg_val, off);
if (ret)
goto exit;

@@ -277,15 +281,7 @@ static int pca953x_gpio_direction_output(struct gpio_chip *gc,

/* then direction */
reg_val = chip->reg_direction[off / BANK_SZ] & ~(1u << (off % BANK_SZ));
- switch (chip->chip_type) {
- case PCA953X_TYPE:
- offset = PCA953X_DIRECTION;
- break;
- case PCA957X_TYPE:
- offset = PCA957X_CFG;
- break;
- }
- ret = pca953x_write_single(chip, offset, reg_val, off);
+ ret = pca953x_write_single(chip, chip->offset->direction, reg_val, off);
if (ret)
goto exit;

@@ -299,18 +295,10 @@ static int pca953x_gpio_get_value(struct gpio_chip *gc, unsigned off)
{
struct pca953x_chip *chip = gpiochip_get_data(gc);
u32 reg_val;
- int ret, offset = 0;
+ int ret;

mutex_lock(&chip->i2c_lock);
- switch (chip->chip_type) {
- case PCA953X_TYPE:
- offset = PCA953X_INPUT;
- break;
- case PCA957X_TYPE:
- offset = PCA957X_IN;
- break;
- }
- ret = pca953x_read_single(chip, offset, &reg_val, off);
+ ret = pca953x_read_single(chip, chip->offset->input, &reg_val, off);
mutex_unlock(&chip->i2c_lock);
if (ret < 0) {
/* NOTE: diagnostic already emitted; that's all we should
@@ -327,7 +315,7 @@ static void pca953x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
{
struct pca953x_chip *chip = gpiochip_get_data(gc);
u8 reg_val;
- int ret, offset = 0;
+ int ret;

mutex_lock(&chip->i2c_lock);
if (val)
@@ -337,15 +325,7 @@ static void pca953x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
reg_val = chip->reg_output[off / BANK_SZ]
& ~(1u << (off % BANK_SZ));

- switch (chip->chip_type) {
- case PCA953X_TYPE:
- offset = PCA953X_OUTPUT;
- break;
- case PCA957X_TYPE:
- offset = PCA957X_OUT;
- break;
- }
- ret = pca953x_write_single(chip, offset, reg_val, off);
+ ret = pca953x_write_single(chip, chip->offset->output, reg_val, off);
if (ret)
goto exit;

@@ -359,19 +339,10 @@ static void pca953x_gpio_set_multiple(struct gpio_chip *gc,
{
struct pca953x_chip *chip = gpiochip_get_data(gc);
u8 reg_val[MAX_BANK];
- int ret, offset = 0;
+ int ret;
int bank_shift = fls((chip->gpio_chip.ngpio - 1) / BANK_SZ);
int bank;

- switch (chip->chip_type) {
- case PCA953X_TYPE:
- offset = PCA953X_OUTPUT;
- break;
- case PCA957X_TYPE:
- offset = PCA957X_OUT;
- break;
- }
-
memcpy(reg_val, chip->reg_output, NBANK(chip));
mutex_lock(&chip->i2c_lock);
for(bank=0; bank<NBANK(chip); bank++) {
@@ -383,7 +354,9 @@ static void pca953x_gpio_set_multiple(struct gpio_chip *gc,
reg_val[bank] = (reg_val[bank] & ~bankmask) | bankval;
}
}
- ret = i2c_smbus_write_i2c_block_data(chip->client, offset << bank_shift, NBANK(chip), reg_val);
+ ret = i2c_smbus_write_i2c_block_data(chip->client,
+ chip->offset->output << bank_shift,
+ NBANK(chip), reg_val);
if (ret)
goto exit;

@@ -515,7 +488,7 @@ static bool pca953x_irq_pending(struct pca953x_chip *chip, u8 *pending)
bool pending_seen = false;
bool trigger_seen = false;
u8 trigger[MAX_BANK];
- int ret, i, offset = 0;
+ int ret, i;

if (chip->driver_data & PCA_PCAL) {
/* Read the current interrupt status from the device */
@@ -540,15 +513,7 @@ static bool pca953x_irq_pending(struct pca953x_chip *chip, u8 *pending)
return pending_seen;
}

- switch (chip->chip_type) {
- case PCA953X_TYPE:
- offset = PCA953X_INPUT;
- break;
- case PCA957X_TYPE:
- offset = PCA957X_IN;
- break;
- }
- ret = pca953x_read_regs(chip, offset, cur_stat);
+ ret = pca953x_read_regs(chip, chip->offset->input, cur_stat);
if (ret)
return false;

@@ -608,20 +573,13 @@ static int pca953x_irq_setup(struct pca953x_chip *chip,
int irq_base)
{
struct i2c_client *client = chip->client;
- int ret, i, offset = 0;
+ int ret, i;

if (client->irq && irq_base != -1
&& (chip->driver_data & PCA_INT)) {

- switch (chip->chip_type) {
- case PCA953X_TYPE:
- offset = PCA953X_INPUT;
- break;
- case PCA957X_TYPE:
- offset = PCA957X_IN;
- break;
- }
- ret = pca953x_read_regs(chip, offset, chip->irq_stat);
+ ret = pca953x_read_regs(chip,
+ chip->offset->input, chip->irq_stat);
if (ret)
return ret;

@@ -684,6 +642,8 @@ static int device_pca953x_init(struct pca953x_chip *chip, u32 invert)
int ret;
u8 val[MAX_BANK];

+ chip->offset = &pca953x_offsets;
+
ret = pca953x_read_regs(chip, PCA953X_OUTPUT, chip->reg_output);
if (ret)
goto out;
@@ -709,6 +669,8 @@ static int device_pca957x_init(struct pca953x_chip *chip, u32 invert)
int ret;
u8 val[MAX_BANK];

+ chip->offset = &pca957x_offsets;
+
ret = pca953x_read_regs(chip, PCA957X_OUT, chip->reg_output);
if (ret)
goto out;
--
2.7.4