power: Add base support for the RK808 PMIC

This Rockchip PMIC provides features suitable for battery-powered
applications. It is commonly used with Rockchip SoCs.

Add a driver which provides register access. The regulator driver will use
this.

Signed-off-by: Simon Glass <sjg@chromium.org>

drivers/power/pmic/Kconfig

@@ -33,6 +33,15 @@ config DM_PMIC_MAX77686
 	This config enables implementation of driver-model pmic uclass features
 	for PMIC MAX77686. The driver implements read/write operations.
 
+config PMIC_RK808
+	bool "Enable support for Rockchip PMIC RK808"
+	depends on DM_PMIC
+	---help---
+	The Rockchip RK808 PMIC provides four buck DC-DC convertors, 8 LDOs,
+	an RTC and two low Rds (resistance (drain to source)) switches. It is
+	accessed via an I2C interface. The device is used with Rockchip SoCs.
+	This driver implements register read/write operations.
+
 config PMIC_S2MPS11
 	bool "Enable Driver Model for PMIC Samsung S2MPS11"
 	depends on DM_PMIC

drivers/power/pmic/Makefile

@@ -11,6 +11,7 @@ obj-$(CONFIG_DM_PMIC_PFUZE100) += pfuze100.o
 obj-$(CONFIG_PMIC_S2MPS11) += s2mps11.o
 obj-$(CONFIG_DM_PMIC_SANDBOX) += sandbox.o i2c_pmic_emul.o
 obj-$(CONFIG_PMIC_ACT8846) += act8846.o
+obj-$(CONFIG_PMIC_RK808) += rk808.o
 obj-$(CONFIG_PMIC_TPS65090) += tps65090.o
 obj-$(CONFIG_PMIC_S5M8767) += s5m8767.o
 

drivers/power/pmic/rk808.c

@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2015 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <fdtdec.h>
+#include <libfdt.h>
+#include <power/rk808_pmic.h>
+#include <power/pmic.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static const struct pmic_child_info pmic_children_info[] = {
+	{ .prefix = "DCDC_REG", .driver = "rk808_buck"},
+	{ .prefix = "LDO_REG", .driver = "rk808_ldo"},
+	{ .prefix = "SWITCH_REG", .driver = "rk808_switch"},
+	{ },
+};
+
+static int rk808_reg_count(struct udevice *dev)
+{
+	return RK808_NUM_OF_REGS;
+}
+
+static int rk808_write(struct udevice *dev, uint reg, const uint8_t *buff,
+			  int len)
+{
+	if (dm_i2c_write(dev, reg, buff, len)) {
+		debug("write error to device: %p register: %#x!", dev, reg);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int rk808_read(struct udevice *dev, uint reg, uint8_t *buff, int len)
+{
+	if (dm_i2c_read(dev, reg, buff, len)) {
+		debug("read error from device: %p register: %#x!", dev, reg);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+#if CONFIG_IS_ENABLED(PMIC_CHILDREN)
+static int rk808_bind(struct udevice *dev)
+{
+	const void *blob = gd->fdt_blob;
+	int regulators_node;
+	int children;
+
+	regulators_node = fdt_subnode_offset(blob, dev->of_offset,
+					     "regulators");
+	if (regulators_node <= 0) {
+		debug("%s: %s regulators subnode not found!", __func__,
+		      dev->name);
+		return -ENXIO;
+	}
+
+	debug("%s: '%s' - found regulators subnode\n", __func__, dev->name);
+
+	children = pmic_bind_children(dev, regulators_node, pmic_children_info);
+	if (!children)
+		debug("%s: %s - no child found\n", __func__, dev->name);
+
+	/* Always return success for this device */
+	return 0;
+}
+#endif
+
+static struct dm_pmic_ops rk808_ops = {
+	.reg_count = rk808_reg_count,
+	.read = rk808_read,
+	.write = rk808_write,
+};
+
+static const struct udevice_id rk808_ids[] = {
+	{ .compatible = "rockchip,rk808" },
+	{ }
+};
+
+U_BOOT_DRIVER(pmic_rk808) = {
+	.name = "rk808 pmic",
+	.id = UCLASS_PMIC,
+	.of_match = rk808_ids,
+#if CONFIG_IS_ENABLED(PMIC_CHILDREN)
+	.bind = rk808_bind,
+#endif
+	.ops = &rk808_ops,
+};