regulator: Factor out common enable code

In preparation of being able to enable/disable GPIO regulators, the
code that will be shared among the two kinds to regulators is factored
out into its own source files.

Signed-off-by: Sven Schwermer <sven@svenschwermer.de>
Reviewed-by: Lukasz Majewski <lukma@denx.de>
diff --git a/drivers/power/regulator/regulator_common.c b/drivers/power/regulator/regulator_common.c
new file mode 100644
index 0000000..3dabbe2
--- /dev/null
+++ b/drivers/power/regulator/regulator_common.c
@@ -0,0 +1,80 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2019 Disruptive Technologies Research AS
+ * Sven Schwermer <sven.svenschwermer@disruptive-technologies.com>
+ */
+
+#include "regulator_common.h"
+#include <common.h>
+#include <power/regulator.h>
+
+int regulator_common_ofdata_to_platdata(struct udevice *dev,
+	struct regulator_common_platdata *dev_pdata, const char *enable_gpio_name)
+{
+	struct gpio_desc *gpio;
+	int flags = GPIOD_IS_OUT;
+	int ret;
+
+	if (dev_read_bool(dev, "enable-active-high"))
+		flags |= GPIOD_IS_OUT_ACTIVE;
+
+	/* Get optional enable GPIO desc */
+	gpio = &dev_pdata->gpio;
+	ret = gpio_request_by_name(dev, enable_gpio_name, 0, gpio, flags);
+	if (ret) {
+		debug("Regulator '%s' optional enable GPIO - not found! Error: %d\n",
+		      dev->name, ret);
+		if (ret != -ENOENT)
+			return ret;
+	}
+
+	/* Get optional ramp up delay */
+	dev_pdata->startup_delay_us = dev_read_u32_default(dev,
+							"startup-delay-us", 0);
+	dev_pdata->off_on_delay_us =
+			dev_read_u32_default(dev, "u-boot,off-on-delay-us", 0);
+
+	return 0;
+}
+
+int regulator_common_get_enable(const struct udevice *dev,
+	struct regulator_common_platdata *dev_pdata)
+{
+	/* Enable GPIO is optional */
+	if (!dev_pdata->gpio.dev)
+		return true;
+
+	return dm_gpio_get_value(&dev_pdata->gpio);
+}
+
+int regulator_common_set_enable(const struct udevice *dev,
+	struct regulator_common_platdata *dev_pdata, bool enable)
+{
+	int ret;
+
+	debug("%s: dev='%s', enable=%d, delay=%d, has_gpio=%d\n", __func__,
+	      dev->name, enable, dev_pdata->startup_delay_us,
+	      dm_gpio_is_valid(&dev_pdata->gpio));
+	/* Enable GPIO is optional */
+	if (!dm_gpio_is_valid(&dev_pdata->gpio)) {
+		if (!enable)
+			return -ENOSYS;
+		return 0;
+	}
+
+	ret = dm_gpio_set_value(&dev_pdata->gpio, enable);
+	if (ret) {
+		pr_err("Can't set regulator : %s gpio to: %d\n", dev->name,
+		      enable);
+		return ret;
+	}
+
+	if (enable && dev_pdata->startup_delay_us)
+		udelay(dev_pdata->startup_delay_us);
+	debug("%s: done\n", __func__);
+
+	if (!enable && dev_pdata->off_on_delay_us)
+		udelay(dev_pdata->off_on_delay_us);
+
+	return 0;
+}