[PATCH v2 2/4] regulator: lp872x: Add enable GPIO pin support

From: Paul Kocialkowski
Date: Fri Feb 05 2016 - 13:43:21 EST


LP872x regulators are made active via the EN pin, which might be hooked to a
GPIO. This adds support for driving the GPIO high when the driver is in use.

Signed-off-by: Paul Kocialkowski <contact@xxxxxxxx>
---
.../devicetree/bindings/regulator/lp872x.txt | 1 +
drivers/regulator/lp872x.c | 34 ++++++++++++++++++++++
include/linux/regulator/lp872x.h | 5 ++++
3 files changed, 40 insertions(+)

diff --git a/Documentation/devicetree/bindings/regulator/lp872x.txt b/Documentation/devicetree/bindings/regulator/lp872x.txt
index 7818318..ca58a68 100644
--- a/Documentation/devicetree/bindings/regulator/lp872x.txt
+++ b/Documentation/devicetree/bindings/regulator/lp872x.txt
@@ -28,6 +28,7 @@ Optional properties:
- ti,dvs-gpio: GPIO specifier for external DVS pin control of LP872x devices.
- ti,dvs-vsel: DVS selector. 0 = SEL_V1, 1 = SEL_V2.
- ti,dvs-state: initial DVS pin state. 0 = DVS_LOW, 1 = DVS_HIGH.
+ - enable-gpios: GPIO specifier for EN pin control of LP872x devices.

Sub nodes for regulator_init_data
LP8720 has maximum 6 nodes. (child name: ldo1 ~ 5 and buck)
diff --git a/drivers/regulator/lp872x.c b/drivers/regulator/lp872x.c
index 21c49d8..3899211 100644
--- a/drivers/regulator/lp872x.c
+++ b/drivers/regulator/lp872x.c
@@ -15,6 +15,7 @@
#include <linux/regmap.h>
#include <linux/err.h>
#include <linux/gpio.h>
+#include <linux/delay.h>
#include <linux/regulator/lp872x.h>
#include <linux/regulator/driver.h>
#include <linux/platform_device.h>
@@ -757,6 +758,33 @@ set_default_dvs_mode:
default_dvs_mode[lp->chipid]);
}

+static int lp872x_hw_enable(struct lp872x *lp)
+{
+ int ret, gpio;
+
+ if (!lp->pdata)
+ return -EINVAL;
+
+ gpio = lp->pdata->enable_gpio;
+ if (!gpio_is_valid(gpio))
+ return 0;
+
+ /* Always set enable GPIO high. */
+ ret = devm_gpio_request_one(lp->dev, gpio, GPIOF_OUT_INIT_HIGH, "LP872X EN");
+ if (ret) {
+ dev_err(lp->dev, "gpio request err: %d\n", ret);
+ return ret;
+ }
+
+ /* Each chip has a different enable delay. */
+ if (lp->chipid == LP8720)
+ usleep_range(LP8720_ENABLE_DELAY, 1.5 * LP8720_ENABLE_DELAY);
+ else
+ usleep_range(LP8725_ENABLE_DELAY, 1.5 * LP8725_ENABLE_DELAY);
+
+ return 0;
+}
+
static int lp872x_config(struct lp872x *lp)
{
struct lp872x_platform_data *pdata = lp->pdata;
@@ -875,6 +903,8 @@ static struct lp872x_platform_data
of_property_read_u8(np, "ti,dvs-state", &dvs_state);
pdata->dvs->init_state = dvs_state ? DVS_HIGH : DVS_LOW;

+ pdata->enable_gpio = of_get_named_gpio(np, "enable-gpios", 0);
+
if (of_get_child_count(np) == 0)
goto out;

@@ -948,6 +978,10 @@ static int lp872x_probe(struct i2c_client *cl, const struct i2c_device_id *id)
lp->chipid = id->driver_data;
i2c_set_clientdata(cl, lp);

+ ret = lp872x_hw_enable(lp);
+ if (ret)
+ return ret;
+
ret = lp872x_config(lp);
if (ret)
return ret;
diff --git a/include/linux/regulator/lp872x.h b/include/linux/regulator/lp872x.h
index 132e05c..6029279 100644
--- a/include/linux/regulator/lp872x.h
+++ b/include/linux/regulator/lp872x.h
@@ -18,6 +18,9 @@

#define LP872X_MAX_REGULATORS 9

+#define LP8720_ENABLE_DELAY 200
+#define LP8725_ENABLE_DELAY 30000
+
enum lp872x_regulator_id {
LP8720_ID_BASE,
LP8720_ID_LDO1 = LP8720_ID_BASE,
@@ -79,12 +82,14 @@ struct lp872x_regulator_data {
* @update_config : if LP872X_GENERAL_CFG register is updated, set true
* @regulator_data : platform regulator id and init data
* @dvs : dvs data for buck voltage control
+ * @enable_gpio : gpio pin number for enable control
*/
struct lp872x_platform_data {
u8 general_config;
bool update_config;
struct lp872x_regulator_data regulator_data[LP872X_MAX_REGULATORS];
struct lp872x_dvs *dvs;
+ int enable_gpio;
};

#endif
--
1.9.1