[PATCH v3 1/2] regulator: s5m8767: Use GPIO for controlling Buck9/eMMC

From: Krzysztof Kozlowski
Date: Fri Jan 24 2014 - 08:38:27 EST

Add support for GPIO control (enable/disable) over Buck9. The Buck9
Converter is used as a supply for eMMC Host Controller.

BUCK9EN GPIO of S5M8767 chip may be used by application processor to
enable or disable the Buck9. This has two benefits:
- It is faster than toggling it over I2C bus.
- It allows disabling the regulator during suspend to RAM; The AP will
enable it during resume; Without the patch the regulator supplying
eMMC must be defined as fixed-regulator.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx>
Cc: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
Cc: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
---
drivers/regulator/s5m8767.c | 87 +++++++++++++++++++++++++++++++++--
include/linux/mfd/samsung/core.h | 3 +-
include/linux/mfd/samsung/s5m8767.h | 7 +++
3 files changed, 93 insertions(+), 4 deletions(-)

diff --git a/drivers/regulator/s5m8767.c b/drivers/regulator/s5m8767.c
index d7164bb75d3e..6850a25a41c4 100644
--- a/drivers/regulator/s5m8767.c
+++ b/drivers/regulator/s5m8767.c
@@ -11,11 +11,8 @@
*
*/

-#include <linux/bug.h>
#include <linux/err.h>
-#include <linux/gpio.h>
#include <linux/of_gpio.h>
-#include <linux/slab.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
@@ -483,6 +480,65 @@ static struct regulator_desc regulators[] = {
s5m8767_regulator_desc(BUCK9),
};

+/*
+ * Enable GPIO control over BUCK9 in regulator_config for that regulator.
+ */
+static void s5m8767_regulator_config_ext_control(struct s5m8767_info *s5m8767,
+ struct sec_regulator_data *rdata,
+ struct regulator_config *config)
+{
+ int i, mode = 0;
+
+ if (rdata->id != S5M8767_BUCK9)
+ return;
+
+ /* Check if opmode for regulator matches S5M8767_ENCTRL_USE_GPIO */
+ for (i = 0; i < s5m8767->num_regulators; i++) {
+ const struct sec_opmode_data *opmode = &s5m8767->opmode[i];
+ if (opmode->id == rdata->id) {
+ mode = s5m8767_opmode_reg[rdata->id][opmode->mode];
+ break;
+ }
+ }
+ if (mode != S5M8767_ENCTRL_USE_GPIO) {
+ dev_warn(s5m8767->dev,
+ "ext-control for %s: mismatched op_mode (%x), ignoring\n",
+ rdata->reg_node->name, mode);
+ return;
+ }
+
+ if (!gpio_is_valid(rdata->ext_control_gpio)) {
+ dev_warn(s5m8767->dev,
+ "ext-control for %s: GPIO not valid, ignoring\n",
+ rdata->reg_node->name);
+ return;
+ }
+
+ config->ena_gpio = rdata->ext_control_gpio;
+ config->ena_gpio_flags = GPIOF_OUT_INIT_HIGH;
+}
+
+/*
+ * Turn on GPIO control over BUCK9.
+ */
+static int s5m8767_enable_ext_control(struct s5m8767_info *s5m8767,
+ struct regulator_dev *rdev)
+{
+ int ret, reg, enable_ctrl;
+
+ if (rdev_get_id(rdev) != S5M8767_BUCK9)
+ return -EINVAL;
+
+ ret = s5m8767_get_register(rdev, &reg, &enable_ctrl);
+ if (ret)
+ return ret;
+
+ return regmap_update_bits(s5m8767->iodev->regmap_pmic,
+ reg, S5M8767_ENCTRL_MASK,
+ S5M8767_ENCTRL_USE_GPIO << S5M8767_ENCTRL_SHIFT);
+}
+
+
#ifdef CONFIG_OF
static int s5m8767_pmic_dt_parse_dvs_gpio(struct sec_pmic_dev *iodev,
struct sec_platform_data *pdata,
@@ -520,6 +576,16 @@ static int s5m8767_pmic_dt_parse_ds_gpio(struct sec_pmic_dev *iodev,
return 0;
}

+static void s5m8767_pmic_dt_parse_ext_control_gpio(struct sec_pmic_dev *iodev,
+ struct sec_regulator_data *rdata,
+ struct device_node *reg_np)
+{
+ rdata->ext_control_gpio = of_get_named_gpio(reg_np,
+ "s5m8767,pmic-ext-control-gpios", 0);
+ if (!gpio_is_valid(rdata->ext_control_gpio))
+ rdata->ext_control_gpio = 0;
+}
+
static int s5m8767_pmic_dt_parse_pdata(struct platform_device *pdev,
struct sec_platform_data *pdata)
{
@@ -574,6 +640,8 @@ static int s5m8767_pmic_dt_parse_pdata(struct platform_device *pdev,
continue;
}

+ s5m8767_pmic_dt_parse_ext_control_gpio(iodev, rdata, reg_np);
+
rdata->id = i;
rdata->initdata = of_get_regulator_init_data(
&pdev->dev, reg_np);
@@ -940,6 +1008,9 @@ static int s5m8767_pmic_probe(struct platform_device *pdev)
config.driver_data = s5m8767;
config.regmap = iodev->regmap_pmic;
config.of_node = pdata->regulators[i].reg_node;
+ if (pdata->regulators[i].ext_control_gpio)
+ s5m8767_regulator_config_ext_control(s5m8767,
+ &pdata->regulators[i], &config);

rdev[i] = devm_regulator_register(&pdev->dev, &regulators[id],
&config);
@@ -949,6 +1020,16 @@ static int s5m8767_pmic_probe(struct platform_device *pdev)
id);
return ret;
}
+
+ if (pdata->regulators[i].ext_control_gpio) {
+ ret = s5m8767_enable_ext_control(s5m8767, rdev[i]);
+ if (ret < 0) {
+ dev_err(s5m8767->dev,
+ "failed to enable gpio control over %s: %d\n",
+ rdev[i]->desc->name, ret);
+ return ret;
+ }
+ }
}

return 0;
diff --git a/include/linux/mfd/samsung/core.h b/include/linux/mfd/samsung/core.h
index 41c9bde410c5..55510444b9fd 100644
--- a/include/linux/mfd/samsung/core.h
+++ b/include/linux/mfd/samsung/core.h
@@ -119,7 +119,8 @@ struct sec_platform_data {
struct sec_regulator_data {
int id;
struct regulator_init_data *initdata;
- struct device_node *reg_node;
+ struct device_node *reg_node;
+ int ext_control_gpio;
};

/*
diff --git a/include/linux/mfd/samsung/s5m8767.h b/include/linux/mfd/samsung/s5m8767.h
index 2ab0b0f03641..243b58fec33d 100644
--- a/include/linux/mfd/samsung/s5m8767.h
+++ b/include/linux/mfd/samsung/s5m8767.h
@@ -183,10 +183,17 @@ enum s5m8767_regulators {
S5M8767_REG_MAX,
};

+/* LDO_EN/BUCK_EN field in registers */
#define S5M8767_ENCTRL_SHIFT 6
#define S5M8767_ENCTRL_MASK (0x3 << S5M8767_ENCTRL_SHIFT)

/*
+ * LDO_EN/BUCK_EN register value for controlling this Buck or LDO
+ * by GPIO (PWREN, BUCKEN).
+ */
+#define S5M8767_ENCTRL_USE_GPIO 0x1
+
+/*
* Values for BUCK_RAMP field in DVS_RAMP register, matching raw values
* in mV/us.
*/
--
1.7.9.5

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