[U-Boot] [PATCH v3 12/17] dm: regulator: add fixed voltage regulator driver

[Przemyslaw Marczak]

This driver implements regulator uclass features for fixed value regulators.
For getting the basic regulator device-tree node constraints, this driver calls
function 'regulator_ofdata_to_platdata()'. The typical fixed regulator node
provides few additional properties:
- gpio
- gpio-open-drain
- enable-active-high
- startup-delay-us
All above are checked and keept in structure of type 'fixed_regulator_priv',
which is private for each fixed-regulator device (dev->priv).

The driver implements only three of regulator uclass features:
- get_value
- get_enable
- set_enable

The regulator calls and command line features can be used for fixed-regulator,
and the proper error will be returned for prohibited.

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

Changes v3:
- new file
- Kconfig add fixed-regulator entry
---
 drivers/power/Kconfig            |   8 +++
 drivers/power/regulator/Makefile |   1 +
 drivers/power/regulator/fixed.c  | 124 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 133 insertions(+)
 create mode 100644 drivers/power/regulator/fixed.c

diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index 97abbf0..da1e866 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -120,6 +120,14 @@ config DM_REGULATOR_MAX77686
 	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.
+
 config AXP221_DCDC1_VOLT
 	int "axp221 dcdc1 voltage"
 	depends on AXP221_POWER
diff --git a/drivers/power/regulator/Makefile b/drivers/power/regulator/Makefile
index 9d282e3..0a6a6d9 100644
--- a/drivers/power/regulator/Makefile
+++ b/drivers/power/regulator/Makefile
@@ -5,4 +5,5 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
+obj-$(CONFIG_DM_REGULATOR_FIXED) += fixed.o
 obj-$(CONFIG_DM_REGULATOR_MAX77686) += max77686.o
diff --git a/drivers/power/regulator/fixed.c b/drivers/power/regulator/fixed.c
new file mode 100644
index 0000000..45e9f84
--- /dev/null
+++ b/drivers/power/regulator/fixed.c
@@ -0,0 +1,124 @@
+/*
+ *  Copyright (C) 2015 Samsung Electronics
+ *
+ *  Przemyslaw Marczak <p.marczak at samsung.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <fdtdec.h>
+#include <i2c.h>
+#include <dm.h>
+#include <asm/gpio.h>
+#include <power/pmic.h>
+#include <power/regulator.h>
+#include <errno.h>
+#include <dm.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct fixed_regulator_priv {
+	struct gpio_desc gpio;
+	bool gpio_open_drain;
+	bool enable_active_high;
+	unsigned startup_delay_us;
+};
+
+static int fixed_regulator_ofdata_to_platdata(struct udevice *dev)
+{
+	struct dm_regulator_info *info = dev->uclass_priv;
+	struct fixed_regulator_priv *priv = dev->priv;
+	int ret, offset = dev->of_offset;
+
+	/* Get the basic regulator constraints */
+	ret = regulator_ofdata_to_platdata(dev);
+	if (ret) {
+		error("Can't get regulator constraints for %s", dev->name);
+		return ret;
+	}
+
+	/* Get fixed regulator gpio desc */
+	ret = gpio_request_by_name_nodev(gd->fdt_blob, offset, "gpio", 0,
+					 &priv->gpio, GPIOD_IS_OUT);
+	if (ret) {
+		error("Fixed regulator gpio - not found! Error: %d", ret);
+		return ret;
+	}
+
+	/* Get fixed regulator addidional constraints */
+	priv->gpio_open_drain = fdtdec_get_bool(gd->fdt_blob, offset,
+						"gpio-open-drain");
+	priv->enable_active_high = fdtdec_get_bool(gd->fdt_blob, offset,
+						   "enable-active-high");
+	priv->startup_delay_us = fdtdec_get_int(gd->fdt_blob, offset,
+						"startup-delay-us", 0);
+
+	/* Set type to fixed - used by regulator command */
+	info->type = REGULATOR_TYPE_FIXED;
+
+	debug("%s:%d\n", __func__, __LINE__);
+	debug(" name:%s, boot_on:%d, active_hi: %d start_delay:%u\n",
+		info->name, info->boot_on, priv->enable_active_high,
+		priv->startup_delay_us);
+
+	return 0;
+}
+
+static int fixed_regulator_get_value(struct udevice *dev)
+{
+	struct dm_regulator_info *info;
+	int ret;
+
+	ret = regulator_info(dev, &info);
+	if (ret)
+		return ret;
+
+	if (info->min_uV == info->max_uV)
+		return info->min_uV;
+
+	error("Invalid constraints for: %s\n", info->name);
+
+	return -EINVAL;
+}
+
+static bool fixed_regulator_get_enable(struct udevice *dev)
+{
+	struct fixed_regulator_priv *priv = dev->priv;
+
+	return dm_gpio_get_value(&priv->gpio);
+}
+
+static int fixed_regulator_set_enable(struct udevice *dev, bool enable)
+{
+	struct fixed_regulator_priv *priv = dev->priv;
+	int ret;
+
+	ret = dm_gpio_set_value(&priv->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_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,
+	.priv_auto_alloc_size = sizeof(struct fixed_regulator_priv),
+};
-- 
1.9.1