gpio/nomadik: disable clocks when unused

The GPIO clock is required for register access and interrupt detection.
When interrupt detection is not required on any of the pin in a block,
the block's clock can be disabled when the registers are not being
accessed.

Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Reviewed-by: Rickard Andersson <rickard.andersson@stericsson.com>
Reviewed-by: Jonas Aberg <jonas.aberg@stericsson.com>
[Adjust for new IRQ chip core code, use only local functions]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 113 insertions, 7 deletions

diff --git a/drivers/gpio/gpio-nomadik.c b/drivers/gpio/gpio-nomadik.c
index 2c212c732d76..97e9be94141b 100644
--- a/drivers/gpio/gpio-nomadik.c
+++ b/drivers/gpio/gpio-nomadik.c
@@ -276,6 +276,8 @@ static void nmk_gpio_glitch_slpm_init(unsigned int *slpm)
                 if (!chip)
                         break;
 
+                clk_enable(chip->clk);
+
                 slpm[i] = readl(chip->addr + NMK_GPIO_SLPC);
                 writel(temp, chip->addr + NMK_GPIO_SLPC);
         }
@@ -292,6 +294,8 @@ static void nmk_gpio_glitch_slpm_restore(unsigned int *slpm)
                         break;
 
                 writel(slpm[i], chip->addr + NMK_GPIO_SLPC);
+
+                clk_disable(chip->clk);
         }
 }
 
@@ -336,10 +340,12 @@ static int __nmk_config_pins(pin_cfg_t *cfgs, int num, bool sleep)
                         break;
                 }
 
+                clk_enable(nmk_chip->clk);
                 spin_lock(&nmk_chip->lock);
                 __nmk_config_pin(nmk_chip, pin - nmk_chip->chip.base,
                                  cfgs[i], sleep, glitch ? slpm : NULL);
                 spin_unlock(&nmk_chip->lock);
+                clk_disable(nmk_chip->clk);
         }
 
         if (glitch)
@@ -424,6 +430,7 @@ int nmk_gpio_set_slpm(int gpio, enum nmk_gpio_slpm mode)
         if (!nmk_chip)
                 return -EINVAL;
 
+        clk_enable(nmk_chip->clk);
         spin_lock_irqsave(&nmk_gpio_slpm_lock, flags);
         spin_lock(&nmk_chip->lock);
 
@@ -431,6 +438,7 @@ int nmk_gpio_set_slpm(int gpio, enum nmk_gpio_slpm mode)
 
         spin_unlock(&nmk_chip->lock);
         spin_unlock_irqrestore(&nmk_gpio_slpm_lock, flags);
+        clk_disable(nmk_chip->clk);
 
         return 0;
 }
@@ -457,9 +465,11 @@ int nmk_gpio_set_pull(int gpio, enum nmk_gpio_pull pull)
         if (!nmk_chip)
                 return -EINVAL;
 
+        clk_enable(nmk_chip->clk);
         spin_lock_irqsave(&nmk_chip->lock, flags);
         __nmk_gpio_set_pull(nmk_chip, gpio - nmk_chip->chip.base, pull);
         spin_unlock_irqrestore(&nmk_chip->lock, flags);
+        clk_disable(nmk_chip->clk);
 
         return 0;
 }
@@ -483,9 +493,11 @@ int nmk_gpio_set_mode(int gpio, int gpio_mode)
         if (!nmk_chip)
                 return -EINVAL;
 
+        clk_enable(nmk_chip->clk);
         spin_lock_irqsave(&nmk_chip->lock, flags);
         __nmk_gpio_set_mode(nmk_chip, gpio - nmk_chip->chip.base, gpio_mode);
         spin_unlock_irqrestore(&nmk_chip->lock, flags);
+        clk_disable(nmk_chip->clk);
 
         return 0;
 }
@@ -502,9 +514,13 @@ int nmk_gpio_get_mode(int gpio)
 
         bit = 1 << (gpio - nmk_chip->chip.base);
 
+        clk_enable(nmk_chip->clk);
+
         afunc = readl(nmk_chip->addr + NMK_GPIO_AFSLA) & bit;
         bfunc = readl(nmk_chip->addr + NMK_GPIO_AFSLB) & bit;
 
+        clk_disable(nmk_chip->clk);
+
         return (afunc ? NMK_GPIO_ALT_A : 0) | (bfunc ? NMK_GPIO_ALT_B : 0);
 }
 EXPORT_SYMBOL(nmk_gpio_get_mode);
@@ -525,7 +541,10 @@ static void nmk_gpio_irq_ack(struct irq_data *d)
         nmk_chip = irq_data_get_irq_chip_data(d);
         if (!nmk_chip)
                 return;
+
+        clk_enable(nmk_chip->clk);
         writel(nmk_gpio_get_bitmask(gpio), nmk_chip->addr + NMK_GPIO_IC);
+        clk_disable(nmk_chip->clk);
 }
 
 enum nmk_gpio_irq_type {
@@ -591,6 +610,7 @@ static int nmk_gpio_irq_maskunmask(struct irq_data *d, bool enable)
         else
                 nmk_chip->enabled &= ~bitmask;
 
+        clk_enable(nmk_chip->clk);
         spin_lock_irqsave(&nmk_gpio_slpm_lock, flags);
         spin_lock(&nmk_chip->lock);
 
@@ -601,6 +621,7 @@ static int nmk_gpio_irq_maskunmask(struct irq_data *d, bool enable)
 
         spin_unlock(&nmk_chip->lock);
         spin_unlock_irqrestore(&nmk_gpio_slpm_lock, flags);
+        clk_disable(nmk_chip->clk);
 
         return 0;
 }
@@ -628,6 +649,7 @@ static int nmk_gpio_irq_set_wake(struct irq_data *d, unsigned int on)
                 return -EINVAL;
         bitmask = nmk_gpio_get_bitmask(gpio);
 
+        clk_enable(nmk_chip->clk);
         spin_lock_irqsave(&nmk_gpio_slpm_lock, flags);
         spin_lock(&nmk_chip->lock);
 
@@ -641,13 +663,15 @@ static int nmk_gpio_irq_set_wake(struct irq_data *d, unsigned int on)
 
         spin_unlock(&nmk_chip->lock);
         spin_unlock_irqrestore(&nmk_gpio_slpm_lock, flags);
+        clk_disable(nmk_chip->clk);
 
         return 0;
 }
 
 static int nmk_gpio_irq_set_type(struct irq_data *d, unsigned int type)
 {
-        bool enabled, wake = irqd_is_wakeup_set(d);
+        bool enabled;
+        bool wake = irqd_is_wakeup_set(d);
         int gpio;
         struct nmk_gpio_chip *nmk_chip;
         unsigned long flags;
@@ -664,10 +688,10 @@ static int nmk_gpio_irq_set_type(struct irq_data *d, unsigned int type)
         if (type & IRQ_TYPE_LEVEL_LOW)
                 return -EINVAL;
 
-        enabled = nmk_chip->enabled & bitmask;
-
+        clk_enable(nmk_chip->clk);
         spin_lock_irqsave(&nmk_chip->lock, flags);
 
+        enabled = !!(nmk_chip->enabled & bitmask);
         if (enabled)
                 __nmk_gpio_irq_modify(nmk_chip, gpio, NORMAL, false);
 
@@ -689,10 +713,28 @@ static int nmk_gpio_irq_set_type(struct irq_data *d, unsigned int type)
                 __nmk_gpio_irq_modify(nmk_chip, gpio, WAKE, true);
 
         spin_unlock_irqrestore(&nmk_chip->lock, flags);
+        clk_disable(nmk_chip->clk);
+
+        return 0;
+}
+
+static unsigned int nmk_gpio_irq_startup(struct irq_data *d)
+{
+        struct nmk_gpio_chip *nmk_chip = irq_data_get_irq_chip_data(d);
 
+        clk_enable(nmk_chip->clk);
+        nmk_gpio_irq_unmask(d);
         return 0;
 }
 
+static void nmk_gpio_irq_shutdown(struct irq_data *d)
+{
+        struct nmk_gpio_chip *nmk_chip = irq_data_get_irq_chip_data(d);
+
+        nmk_gpio_irq_mask(d);
+        clk_disable(nmk_chip->clk);
+}
+
 static struct irq_chip nmk_gpio_irq_chip = {
         .name           = "Nomadik-GPIO",
         .irq_ack        = nmk_gpio_irq_ack,
@@ -700,6 +742,8 @@ static struct irq_chip nmk_gpio_irq_chip = {
         .irq_unmask     = nmk_gpio_irq_unmask,
         .irq_set_type   = nmk_gpio_irq_set_type,
         .irq_set_wake   = nmk_gpio_irq_set_wake,
+        .irq_startup    = nmk_gpio_irq_startup,
+        .irq_shutdown   = nmk_gpio_irq_shutdown,
 };
 
 static void __nmk_gpio_irq_handler(unsigned int irq, struct irq_desc *desc,
@@ -726,7 +770,11 @@ static void __nmk_gpio_irq_handler(unsigned int irq, struct irq_desc *desc,
 static void nmk_gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
 {
         struct nmk_gpio_chip *nmk_chip = irq_get_handler_data(irq);
-        u32 status = readl(nmk_chip->addr + NMK_GPIO_IS);
+        u32 status;
+
+        clk_enable(nmk_chip->clk);
+        status = readl(nmk_chip->addr + NMK_GPIO_IS);
+        clk_disable(nmk_chip->clk);
 
         __nmk_gpio_irq_handler(irq, desc, status);
 }
@@ -772,7 +820,12 @@ static int nmk_gpio_make_input(struct gpio_chip *chip, unsigned offset)
         struct nmk_gpio_chip *nmk_chip =
                 container_of(chip, struct nmk_gpio_chip, chip);
 
+        clk_enable(nmk_chip->clk);
+
         writel(1 << offset, nmk_chip->addr + NMK_GPIO_DIRC);
+
+        clk_disable(nmk_chip->clk);
+
         return 0;
 }
 
@@ -781,8 +834,15 @@ static int nmk_gpio_get_input(struct gpio_chip *chip, unsigned offset)
         struct nmk_gpio_chip *nmk_chip =
                 container_of(chip, struct nmk_gpio_chip, chip);
         u32 bit = 1 << offset;
+        int value;
+
+        clk_enable(nmk_chip->clk);
+
+        value = (readl(nmk_chip->addr + NMK_GPIO_DAT) & bit) != 0;
 
-        return (readl(nmk_chip->addr + NMK_GPIO_DAT) & bit) != 0;
+        clk_disable(nmk_chip->clk);
+
+        return value;
 }
 
 static void nmk_gpio_set_output(struct gpio_chip *chip, unsigned offset,
@@ -791,7 +851,11 @@ static void nmk_gpio_set_output(struct gpio_chip *chip, unsigned offset,
         struct nmk_gpio_chip *nmk_chip =
                 container_of(chip, struct nmk_gpio_chip, chip);
 
+        clk_enable(nmk_chip->clk);
+
         __nmk_gpio_set_output(nmk_chip, offset, val);
+
+        clk_disable(nmk_chip->clk);
 }
 
 static int nmk_gpio_make_output(struct gpio_chip *chip, unsigned offset,
@@ -800,8 +864,12 @@ static int nmk_gpio_make_output(struct gpio_chip *chip, unsigned offset,
         struct nmk_gpio_chip *nmk_chip =
                 container_of(chip, struct nmk_gpio_chip, chip);
 
+        clk_enable(nmk_chip->clk);
+
         __nmk_gpio_make_output(nmk_chip, offset, val);
 
+        clk_disable(nmk_chip->clk);
+
         return 0;
 }
 
@@ -832,6 +900,8 @@ static void nmk_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
                 [NMK_GPIO_ALT_C]        = "altC",
         };
 
+        clk_enable(nmk_chip->clk);
+
         for (i = 0; i < chip->ngpio; i++, gpio++) {
                 const char *label = gpiochip_is_requested(chip, i);
                 bool pull;
@@ -876,6 +946,8 @@ static void nmk_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 
                 seq_printf(s, "\n");
         }
+
+        clk_disable(nmk_chip->clk);
 }
 
 #else
@@ -893,6 +965,34 @@ static struct gpio_chip nmk_gpio_template = {
         .can_sleep              = 0,
 };
 
+void nmk_gpio_clocks_enable(void)
+{
+        int i;
+
+        for (i = 0; i < NUM_BANKS; i++) {
+                struct nmk_gpio_chip *chip = nmk_gpio_chips[i];
+
+                if (!chip)
+                        continue;
+
+                clk_enable(chip->clk);
+        }
+}
+
+void nmk_gpio_clocks_disable(void)
+{
+        int i;
+
+        for (i = 0; i < NUM_BANKS; i++) {
+                struct nmk_gpio_chip *chip = nmk_gpio_chips[i];
+
+                if (!chip)
+                        continue;
+
+                clk_disable(chip->clk);
+        }
+}
+
 /*
  * Called from the suspend/resume path to only keep the real wakeup interrupts
  * (those that have had set_irq_wake() called on them) as wakeup interrupts,
@@ -912,6 +1012,8 @@ void nmk_gpio_wakeups_suspend(void)
                 if (!chip)
                         break;
 
+                clk_enable(chip->clk);
+
                 chip->rwimsc = readl(chip->addr + NMK_GPIO_RWIMSC);
                 chip->fwimsc = readl(chip->addr + NMK_GPIO_FWIMSC);
 
@@ -926,6 +1028,8 @@ void nmk_gpio_wakeups_suspend(void)
                         /* 0 -> wakeup enable */
                         writel(~chip->real_wake, chip->addr + NMK_GPIO_SLPC);
                 }
+
+                clk_disable(chip->clk);
         }
 }
 
@@ -939,11 +1043,15 @@ void nmk_gpio_wakeups_resume(void)
                 if (!chip)
                         break;
 
+                clk_enable(chip->clk);
+
                 writel(chip->rwimsc, chip->addr + NMK_GPIO_RWIMSC);
                 writel(chip->fwimsc, chip->addr + NMK_GPIO_FWIMSC);
 
                 if (chip->sleepmode)
                         writel(chip->slpm, chip->addr + NMK_GPIO_SLPC);
+
+                clk_disable(chip->clk);
         }
 }
 
@@ -1010,8 +1118,6 @@ static int __devinit nmk_gpio_probe(struct platform_device *dev)
                 goto out_release;
         }
 
-        clk_enable(clk);
-
         nmk_chip = kzalloc(sizeof(*nmk_chip), GFP_KERNEL);
         if (!nmk_chip) {
                 ret = -ENOMEM;