regulator: Add 'start-up time' to fixed voltage regulators

Add a field to specify a delay for the start-up time of
a fixed voltage regulator.

Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

2 files changed, 7 insertions, 0 deletions

diff --git a/drivers/regulator/fixed.c b/drivers/regulator/fixed.c
index f9f516a3028a..ee3e7eb97b1c 100644
--- a/drivers/regulator/fixed.c
+++ b/drivers/regulator/fixed.c
@@ -24,12 +24,14 @@
 #include <linux/regulator/driver.h>
 #include <linux/regulator/fixed.h>
 #include <linux/gpio.h>
+#include <linux/delay.h>
 
 struct fixed_voltage_data {
         struct regulator_desc desc;
         struct regulator_dev *dev;
         int microvolts;
         int gpio;
+        unsigned startup_delay;
         unsigned enable_high:1;
         unsigned is_enabled:1;
 };
@@ -48,6 +50,8 @@ static int fixed_voltage_enable(struct regulator_dev *dev)
         if (gpio_is_valid(data->gpio)) {
                 gpio_set_value_cansleep(data->gpio, data->enable_high);
                 data->is_enabled = 1;
+                if (data->startup_delay)
+                        udelay(data->startup_delay);
         }
 
         return 0;
@@ -117,6 +121,7 @@ static int regulator_fixed_voltage_probe(struct platform_device *pdev)
 
         drvdata->microvolts = config->microvolts;
         drvdata->gpio = config->gpio;
+        drvdata->startup_delay = config->startup_delay;
 
         if (gpio_is_valid(config->gpio)) {
                 drvdata->enable_high = config->enable_high;
diff --git a/include/linux/regulator/fixed.h b/include/linux/regulator/fixed.h
index e94a4a1c7c8a..ffd7d508e726 100644
--- a/include/linux/regulator/fixed.h
+++ b/include/linux/regulator/fixed.h
@@ -25,6 +25,7 @@ struct regulator_init_data;
  * @microvolts:         Output voltage of regulator
  * @gpio:               GPIO to use for enable control
  *                      set to -EINVAL if not used
+ * @startup_delay:      Start-up time in microseconds
  * @enable_high:        Polarity of enable GPIO
  *                      1 = Active high, 0 = Active low
  * @enabled_at_boot:    Whether regulator has been enabled at
@@ -41,6 +42,7 @@ struct fixed_voltage_config {
         const char *supply_name;
         int microvolts;
         int gpio;
+        unsigned startup_delay;
         unsigned enable_high:1;
         unsigned enabled_at_boot:1;
         struct regulator_init_data *init_data;