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gpio: twl4030: Introduce private structure to store variables needed …
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…runtime

Move most of the global variables inside a private structure and allocate
it dynamically.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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Peter Ujfalusi authored and Linus Walleij committed Jan 17, 2013
1 parent ebe5a05 commit 72c7901
Showing 1 changed file with 50 additions and 32 deletions.
82 changes: 50 additions & 32 deletions drivers/gpio/gpio-twl4030.c
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Original file line number Diff line number Diff line change
Expand Up @@ -49,11 +49,6 @@
* There are also two LED pins used sometimes as output-only GPIOs.
*/


static struct gpio_chip twl_gpiochip;
static int twl4030_gpio_base;
static int twl4030_gpio_irq_base;

/* genirq interfaces are not available to modules */
#ifdef MODULE
#define is_module() true
Expand All @@ -72,11 +67,20 @@ static int twl4030_gpio_irq_base;
/* Data structures */
static DEFINE_MUTEX(gpio_lock);

/* store usage of each GPIO. - each bit represents one GPIO */
static unsigned int gpio_usage_count;
struct gpio_twl4030_priv {
struct gpio_chip gpio_chip;
int irq_base;

unsigned int usage_count;
};

/*----------------------------------------------------------------------*/

static inline struct gpio_twl4030_priv *to_gpio_twl4030(struct gpio_chip *chip)
{
return container_of(chip, struct gpio_twl4030_priv, gpio_chip);
}

/*
* To configure TWL4030 GPIO module registers
*/
Expand Down Expand Up @@ -193,10 +197,6 @@ static int twl4030_get_gpio_datain(int gpio)
u8 base = 0;
int ret = 0;

if (unlikely((gpio >= TWL4030_GPIO_MAX)
|| !(gpio_usage_count & BIT(gpio))))
return -EPERM;

base = REG_GPIODATAIN1 + d_bnk;
ret = gpio_twl4030_read(base);
if (ret > 0)
Expand All @@ -209,6 +209,7 @@ static int twl4030_get_gpio_datain(int gpio)

static int twl_request(struct gpio_chip *chip, unsigned offset)
{
struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip);
int status = 0;

mutex_lock(&gpio_lock);
Expand Down Expand Up @@ -252,7 +253,7 @@ static int twl_request(struct gpio_chip *chip, unsigned offset)
}

/* on first use, turn GPIO module "on" */
if (!gpio_usage_count) {
if (!priv->usage_count) {
struct twl4030_gpio_platform_data *pdata;
u8 value = MASK_GPIO_CTRL_GPIO_ON;

Expand All @@ -266,27 +267,29 @@ static int twl_request(struct gpio_chip *chip, unsigned offset)
status = gpio_twl4030_write(REG_GPIO_CTRL, value);
}

done:
if (!status)
gpio_usage_count |= (0x1 << offset);
priv->usage_count |= BIT(offset);

done:
mutex_unlock(&gpio_lock);
return status;
}

static void twl_free(struct gpio_chip *chip, unsigned offset)
{
struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip);

if (offset >= TWL4030_GPIO_MAX) {
twl4030_led_set_value(offset - TWL4030_GPIO_MAX, 1);
return;
}

mutex_lock(&gpio_lock);

gpio_usage_count &= ~BIT(offset);
priv->usage_count &= ~BIT(offset);

/* on last use, switch off GPIO module */
if (!gpio_usage_count)
if (!priv->usage_count)
gpio_twl4030_write(REG_GPIO_CTRL, 0x0);

mutex_unlock(&gpio_lock);
Expand All @@ -301,14 +304,19 @@ static int twl_direction_in(struct gpio_chip *chip, unsigned offset)

static int twl_get(struct gpio_chip *chip, unsigned offset)
{
struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip);
int status = 0;

if (!(priv->usage_count & BIT(offset)))
return -EPERM;

if (offset < TWL4030_GPIO_MAX)
status = twl4030_get_gpio_datain(offset);
else if (offset == TWL4030_GPIO_MAX)
status = cached_leden & LEDEN_LEDAON;
else
status = cached_leden & LEDEN_LEDBON;

return (status < 0) ? 0 : status;
}

Expand All @@ -333,12 +341,14 @@ static void twl_set(struct gpio_chip *chip, unsigned offset, int value)

static int twl_to_irq(struct gpio_chip *chip, unsigned offset)
{
return (twl4030_gpio_irq_base && (offset < TWL4030_GPIO_MAX))
? (twl4030_gpio_irq_base + offset)
struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip);

return (priv->irq_base && (offset < TWL4030_GPIO_MAX))
? (priv->irq_base + offset)
: -EINVAL;
}

static struct gpio_chip twl_gpiochip = {
static struct gpio_chip template_chip = {
.label = "twl4030",
.owner = THIS_MODULE,
.request = twl_request,
Expand Down Expand Up @@ -424,8 +434,14 @@ static int gpio_twl4030_probe(struct platform_device *pdev)
{
struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data;
struct device_node *node = pdev->dev.of_node;
struct gpio_twl4030_priv *priv;
int ret, irq_base;

priv = devm_kzalloc(&pdev->dev, sizeof(struct gpio_twl4030_priv),
GFP_KERNEL);
if (!priv)
return -ENOMEM;

/* maybe setup IRQs */
if (is_module()) {
dev_err(&pdev->dev, "can't dispatch IRQs from modules\n");
Expand All @@ -445,12 +461,13 @@ static int gpio_twl4030_probe(struct platform_device *pdev)
if (ret < 0)
return ret;

twl4030_gpio_irq_base = irq_base;
priv->irq_base = irq_base;

no_irqs:
twl_gpiochip.base = -1;
twl_gpiochip.ngpio = TWL4030_GPIO_MAX;
twl_gpiochip.dev = &pdev->dev;
priv->gpio_chip = template_chip;
priv->gpio_chip.base = -1;
priv->gpio_chip.ngpio = TWL4030_GPIO_MAX;
priv->gpio_chip.dev = &pdev->dev;

if (node)
pdata = of_gpio_twl4030(&pdev->dev);
Expand Down Expand Up @@ -481,23 +498,23 @@ static int gpio_twl4030_probe(struct platform_device *pdev)
* is (still) clear if use_leds is set.
*/
if (pdata->use_leds)
twl_gpiochip.ngpio += 2;
priv->gpio_chip.ngpio += 2;

ret = gpiochip_add(&twl_gpiochip);
ret = gpiochip_add(&priv->gpio_chip);
if (ret < 0) {
dev_err(&pdev->dev, "could not register gpiochip, %d\n", ret);
twl_gpiochip.ngpio = 0;
priv->gpio_chip.ngpio = 0;
gpio_twl4030_remove(pdev);
goto out;
}

twl4030_gpio_base = twl_gpiochip.base;
platform_set_drvdata(pdev, priv);

if (pdata && pdata->setup) {
int status;

status = pdata->setup(&pdev->dev,
twl4030_gpio_base, TWL4030_GPIO_MAX);
status = pdata->setup(&pdev->dev, priv->gpio_chip.base,
TWL4030_GPIO_MAX);
if (status)
dev_dbg(&pdev->dev, "setup --> %d\n", status);
}
Expand All @@ -510,18 +527,19 @@ static int gpio_twl4030_probe(struct platform_device *pdev)
static int gpio_twl4030_remove(struct platform_device *pdev)
{
struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data;
struct gpio_twl4030_priv *priv = platform_get_drvdata(pdev);
int status;

if (pdata && pdata->teardown) {
status = pdata->teardown(&pdev->dev,
twl4030_gpio_base, TWL4030_GPIO_MAX);
status = pdata->teardown(&pdev->dev, priv->gpio_chip.base,
TWL4030_GPIO_MAX);
if (status) {
dev_dbg(&pdev->dev, "teardown --> %d\n", status);
return status;
}
}

status = gpiochip_remove(&twl_gpiochip);
status = gpiochip_remove(&priv->gpio_chip);
if (status < 0)
return status;

Expand Down

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