From 849369d6c66d3054688672f97d31fceb8e8230fb Mon Sep 17 00:00:00 2001
From: root <root@artemis.panaceas.org>
Date: Fri, 25 Dec 2015 04:40:36 +0000
Subject: initial_commit

---
 Documentation/power/regulator/machine.txt | 93 +++++++++++++++++++++++++++++++
 1 file changed, 93 insertions(+)
 create mode 100644 Documentation/power/regulator/machine.txt

(limited to 'Documentation/power/regulator/machine.txt')

diff --git a/Documentation/power/regulator/machine.txt b/Documentation/power/regulator/machine.txt
new file mode 100644
index 00000000..b42419b5
--- /dev/null
+++ b/Documentation/power/regulator/machine.txt
@@ -0,0 +1,93 @@
+Regulator Machine Driver Interface
+===================================
+
+The regulator machine driver interface is intended for board/machine specific
+initialisation code to configure the regulator subsystem.
+
+Consider the following machine :-
+
+  Regulator-1 -+-> Regulator-2 --> [Consumer A @ 1.8 - 2.0V]
+               |
+               +-> [Consumer B @ 3.3V]
+
+The drivers for consumers A & B must be mapped to the correct regulator in
+order to control their power supply. This mapping can be achieved in machine
+initialisation code by creating a struct regulator_consumer_supply for
+each regulator.
+
+struct regulator_consumer_supply {
+	struct device *dev;	/* consumer */
+	const char *supply;	/* consumer supply - e.g. "vcc" */
+};
+
+e.g. for the machine above
+
+static struct regulator_consumer_supply regulator1_consumers[] = {
+{
+	.dev	= &platform_consumerB_device.dev,
+	.supply	= "Vcc",
+},};
+
+static struct regulator_consumer_supply regulator2_consumers[] = {
+{
+	.dev	= &platform_consumerA_device.dev,
+	.supply	= "Vcc",
+},};
+
+This maps Regulator-1 to the 'Vcc' supply for Consumer B and maps Regulator-2
+to the 'Vcc' supply for Consumer A.
+
+Constraints can now be registered by defining a struct regulator_init_data
+for each regulator power domain. This structure also maps the consumers
+to their supply regulator :-
+
+static struct regulator_init_data regulator1_data = {
+	.constraints = {
+		.min_uV = 3300000,
+		.max_uV = 3300000,
+		.valid_modes_mask = REGULATOR_MODE_NORMAL,
+	},
+	.num_consumer_supplies = ARRAY_SIZE(regulator1_consumers),
+	.consumer_supplies = regulator1_consumers,
+};
+
+Regulator-1 supplies power to Regulator-2. This relationship must be registered
+with the core so that Regulator-1 is also enabled when Consumer A enables its
+supply (Regulator-2). The supply regulator is set by the supply_regulator
+field below:-
+
+static struct regulator_init_data regulator2_data = {
+	.supply_regulator = "regulator_name",
+	.constraints = {
+		.min_uV = 1800000,
+		.max_uV = 2000000,
+		.valid_ops_mask = REGULATOR_CHANGE_VOLTAGE,
+		.valid_modes_mask = REGULATOR_MODE_NORMAL,
+	},
+	.num_consumer_supplies = ARRAY_SIZE(regulator2_consumers),
+	.consumer_supplies = regulator2_consumers,
+};
+
+Finally the regulator devices must be registered in the usual manner.
+
+static struct platform_device regulator_devices[] = {
+{
+	.name = "regulator",
+	.id = DCDC_1,
+	.dev = {
+		.platform_data = &regulator1_data,
+	},
+},
+{
+	.name = "regulator",
+	.id = DCDC_2,
+	.dev = {
+		.platform_data = &regulator2_data,
+	},
+},
+};
+/* register regulator 1 device */
+platform_device_register(&regulator_devices[0]);
+
+/* register regulator 2 device */
+platform_device_register(&regulator_devices[1]);
-- 
cgit v1.2.3