[U-Boot] [PATCH v4 11/16] dm: regulator: add fixed voltage regulator driver

Przemyslaw Marczak
2015-04-20T18:07:48Z

This driver implements regulator operations for fixed Voltage/Current
value regulators. beside the standard regulator constraints, which are
put into the uclass platform data, a typical fixed regulator node provides
few additional properties like:
- gpio
- gpio-open-drain
- enable-active-high
- startup-delay-us
The only 'gpio' is used by this driver and is kept in structure of type
'fixed_regulator_platdata', as a device platform data (dev->platdata).

The driver implements:
- get_value
- get_current
- get_enable
- set_enable

The regulator calls and commands can be used for fixed-regulator devices,
and the proper error will be returned for prohibited.

Signed-off-by: Przemyslaw Marczak <p.marczak@samsung.com>

Changes v3:
- new file
- Kconfig add fixed-regulator entry

Changes V4:
- move DM_REGULATOR_FIXED Kconfig entry from: drivers/power/Kconfig to
drivers/power/regulator/Kconfig
- regulator/fixed.c: adjust to use of uclass platdata and device platdata
- regulator/fixed.c: includes cleanup
- regulator/fixed.c: fix gpio request
- add binding info
---
doc/device-tree-bindings/regulator/fixed.txt | 38 ++++++++
drivers/power/regulator/Kconfig | 8 ++
drivers/power/regulator/Makefile | 1 +
drivers/power/regulator/fixed.c | 126 +++++++++++++++++++++++++++
4 files changed, 173 insertions(+)
create mode 100644 doc/device-tree-bindings/regulator/fixed.txt
create mode 100644 drivers/power/regulator/fixed.c

diff --git a/doc/device-tree-bindings/regulator/fixed.txt b/doc/device-tree-bindings/regulator/fixed.txt
new file mode 100644
index 0000000..4ff39b8
--- /dev/null
+++ b/doc/device-tree-bindings/regulator/fixed.txt
@@ -0,0 +1,38 @@
+Fixed Voltage regulator
+
+Binding:
+The binding is done by the property "compatible" - this is different, than for
+binding by the node prefix (doc/device-tree-bindings/regulator/regulator.txt).
+
+Required properties:
+- compatible: "regulator-fixed"
+- regulator-name: this is required by the regulator uclass
+
+Optional properties:
+- gpio: GPIO to use for enable control
+- regulator constraints (binding info: regulator.txt)
+
+Other kernel-style properties, are currently not used.
+
+Note:
+For the regulator constraints, driver expects that:
+- regulator-min-microvolt is equal to regulator-max-microvolt
+- regulator-min-microamp is equal to regulator-max-microamp
+
+Example:
+fixed_regulator at 0 {
+ /* Mandatory */
+ compatible = "regulator-fixed";
+ regulator-name = "LED_3.3V";
+
+ /* Optional: */
+ gpio = <&gpc1 0 GPIO_ACTIVE_LOW>;
+
+ /* Optional for regulator uclass */
+ regulator-min-microvolt = <3300000>;
+ regulator-max-microvolt = <3300000>;
+ regulator-min-microamp = <15000>;
+ regulator-max-microamp = <15000>;
+ regulator-always-on;
+ regulator-boot-on;
+};
diff --git a/drivers/power/regulator/Kconfig b/drivers/power/regulator/Kconfig
index 0cdfabc..54ce188 100644
--- a/drivers/power/regulator/Kconfig
+++ b/drivers/power/regulator/Kconfig
@@ -23,3 +23,11 @@ config DM_REGULATOR_MAX77686
This config enables implementation of driver-model regulator uclass
features for REGULATOR MAX77686. The driver implements get/set api for:
value, enable and mode.
+
+config DM_REGULATOR_FIXED
+ bool "Enable Driver Model for REGULATOR Fixed value"
+ depends on DM_REGULATOR
+ ---help---
+ This config enables implementation of driver-model regulator uclass
+ features for fixed value regulators. The driver implements get/set api
+ for enable and get only for voltage value.
diff --git a/drivers/power/regulator/Makefile b/drivers/power/regulator/Makefile
index f9c4e6d..cc8326d 100644
--- a/drivers/power/regulator/Makefile
+++ b/drivers/power/regulator/Makefile
@@ -7,3 +7,4 @@

obj-$(CONFIG_DM_REGULATOR) += regulator-uclass.o
obj-$(CONFIG_DM_REGULATOR_MAX77686) += max77686.o
+obj-$(CONFIG_DM_REGULATOR_FIXED) += fixed.o
diff --git a/drivers/power/regulator/fixed.c b/drivers/power/regulator/fixed.c
new file mode 100644
index 0000000..d053817
--- /dev/null
+++ b/drivers/power/regulator/fixed.c
@@ -0,0 +1,126 @@
+/*
+ * Copyright (C) 2015 Samsung Electronics
+ *
+ * Przemyslaw Marczak <p.marczak@samsung.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <fdtdec.h>
+#include <errno.h>
+#include <dm.h>
+#include <i2c.h>
+#include <asm/gpio.h>
+#include <power/pmic.h>
+#include <power/regulator.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct fixed_regulator_platdata {
+ struct gpio_desc gpio; /* GPIO for regulator enable control */
+};
+
+static int fixed_regulator_ofdata_to_platdata(struct udevice *dev)
+{
+ struct dm_regulator_uclass_platdata *uc_pdata;
+ struct fixed_regulator_platdata *dev_pdata;
+ struct gpio_desc *gpio;
+ int ret;
+
+ dev_pdata = dev_get_platdata(dev);
+ uc_pdata = dev_get_uclass_platdata(dev);
+ if (!uc_pdata)
+ return -ENXIO;
+
+ /* Set type to fixed */
+ uc_pdata->type = REGULATOR_TYPE_FIXED;
+
+ /* Get fixed regulator gpio desc */
+ gpio = &dev_pdata->gpio;
+ ret = gpio_request_by_name(dev, "gpio", 0, gpio, GPIOD_IS_OUT);
+ if (ret)
+ debug("Fixed regulator gpio - not found! Error: %d", ret);
+
+ return 0;
+}
+
+static int fixed_regulator_get_value(struct udevice *dev)
+{
+ struct dm_regulator_uclass_platdata *uc_pdata;
+
+ uc_pdata = dev_get_uclass_platdata(dev);
+ if (!uc_pdata)
+ return -ENXIO;
+
+ if (uc_pdata->min_uV != uc_pdata->max_uV) {
+ debug("Invalid constraints for: %s\n", uc_pdata->name);
+ return -EINVAL;
+ }
+
+ return uc_pdata->min_uV;
+}
+
+static int fixed_regulator_get_current(struct udevice *dev)
+{
+ struct dm_regulator_uclass_platdata *uc_pdata;
+
+ uc_pdata = dev_get_uclass_platdata(dev);
+ if (!uc_pdata)
+ return -ENXIO;
+
+ if (uc_pdata->min_uA != uc_pdata->max_uA) {
+ debug("Invalid constraints for: %s\n", uc_pdata->name);
+ return -EINVAL;
+ }
+
+ return uc_pdata->min_uA;
+}
+
+static bool fixed_regulator_get_enable(struct udevice *dev)
+{
+ struct fixed_regulator_platdata *dev_pdata = dev_get_platdata(dev);
+
+ if (!dev_pdata->gpio.dev)
+ return false;
+
+ return dm_gpio_get_value(&dev_pdata->gpio);
+}
+
+static int fixed_regulator_set_enable(struct udevice *dev, bool enable)
+{
+ struct fixed_regulator_platdata *dev_pdata = dev_get_platdata(dev);
+ int ret;
+
+ if (!dev_pdata->gpio.dev)
+ return -ENOSYS;
+
+ ret = dm_gpio_set_value(&dev_pdata->gpio, enable);
+ if (ret) {
+ error("Can't set regulator : %s gpio to: %d\n", dev->name,
+ enable);
+ return ret;
+ }
+ return 0;
+}
+
+static const struct dm_regulator_ops fixed_regulator_ops = {
+ .get_value = fixed_regulator_get_value,
+ .get_current = fixed_regulator_get_current,
+ .get_enable = fixed_regulator_get_enable,
+ .set_enable = fixed_regulator_set_enable,
+};
+
+static const struct udevice_id fixed_regulator_ids[] = {
+ { .compatible = "regulator-fixed" },
+ { },
+};
+
+U_BOOT_DRIVER(fixed_regulator) = {
+ .name = "fixed regulator",
+ .id = UCLASS_REGULATOR,
+ .ops = &fixed_regulator_ops,
+ .of_match = fixed_regulator_ids,
+ .ofdata_to_platdata = fixed_regulator_ofdata_to_platdata,
+ .platdata_auto_alloc_size = sizeof(struct fixed_regulator_platdata),
+};
--
1.9.1