gpio: twl4030: Introduce private structure to store variables needed 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>

1 files changed, 50 insertions, 32 deletions

diff --git a/drivers/gpio/gpio-twl4030.c b/drivers/gpio/gpio-twl4030.c
index 9572aa137e6f..4643f9cd0cae 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 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 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;