Re: [PATCH v2 1/3] gpio: twl4030: Introduce private structure to store variables needed runtime

From: Grant Likely
Date: Wed Dec 19 2012 - 15:35:59 EST


On Thu, 6 Dec 2012 11:52:05 +0100, Peter Ujfalusi <peter.ujfalusi@xxxxxx> wrote:
> Move most of the global variables inside a private structure and allocate
> it dynamically.
>
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx>

Applied, thanks

g.

> ---
> drivers/gpio/gpio-twl4030.c | 82 +++++++++++++++++++++++++++------------------
> 1 file changed, 50 insertions(+), 32 deletions(-)
>
> diff --git a/drivers/gpio/gpio-twl4030.c b/drivers/gpio/gpio-twl4030.c
> index 55b4fe4..c092739 100644
> --- a/drivers/gpio/gpio-twl4030.c
> +++ b/drivers/gpio/gpio-twl4030.c
> @@ -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
> @@ -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
> */
> @@ -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)
> @@ -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);
> @@ -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;
>
> @@ -266,16 +267,18 @@ 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;
> @@ -283,10 +286,10 @@ static void twl_free(struct gpio_chip *chip, unsigned offset)
>
> 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);
> @@ -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;
> }
>
> @@ -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,
> @@ -424,8 +434,14 @@ static int __devinit 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");
> @@ -445,12 +461,13 @@ static int __devinit 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);
> @@ -481,23 +498,23 @@ no_irqs:
> * 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);
> }
> @@ -510,18 +527,19 @@ out:
> 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;
>
> --
> 1.8.0
>

--
Grant Likely, B.Sc, P.Eng.
Secret Lab Technologies, Ltd.
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