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

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




Hi Paul,

Thanks for the patch. Please see my comments below.

On 2/6/2016 3:42 AM, Paul Kocialkowski wrote:
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;

It seems gpio is always 0 when it starts from DT. 'enable_gpio' is updated in lp872x_config() but lp872x_hw_enable() is called first.

+
+	/* 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);

Please move this code to lp872x_populate_pdata_from_dt().
lp872x_hw_enable() is called prior to lp872x_config(), so enable_gpio should be set on parsing the DT properties.

+
  	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


Best regards,
Milo
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Device Tree Compilter]     [Device Tree Spec]     [Linux Driver Backports]     [Video for Linux]     [Linux USB Devel]     [Linux PCI Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Yosemite Backpacking]
  Powered by Linux