power: Add support for ACT8846 PMIC

Add a driver for the ACT8846 PMIC. This supports several LDOs and BUCKs and
is connected to the I2C bus. This driver supports using a regulator driver
to access the regulators.

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

drivers/power/pmic/Kconfig

@@ -10,6 +10,15 @@ config DM_PMIC
 	- 'drivers/power/pmic/pmic-uclass.c'
 	- 'include/power/pmic.h'
 
+config PMIC_ACT8846
+	bool "Enable support for the active-semi 8846 PMIC"
+	depends on DM_PMIC && DM_I2C
+	---help---
+	This PMIC includes 4 DC/DC step-down buck regulators and 8 low-dropout
+	regulators (LDOs). It also provides some GPIO, reset and battery
+	functions. It uses an I2C interface and is designed for use with
+	tablets and smartphones.
+
 config DM_PMIC_PFUZE100
 	bool "Enable Driver Model for PMIC PFUZE100"
 	depends on DM_PMIC

drivers/power/pmic/Makefile

@@ -9,6 +9,7 @@ obj-$(CONFIG_DM_PMIC) += pmic-uclass.o
 obj-$(CONFIG_DM_PMIC_MAX77686) += max77686.o
 obj-$(CONFIG_DM_PMIC_PFUZE100) += pfuze100.o
 obj-$(CONFIG_DM_PMIC_SANDBOX) += sandbox.o i2c_pmic_emul.o
+obj-$(CONFIG_PMIC_ACT8846) += act8846.o
 obj-$(CONFIG_PMIC_TPS65090) += tps65090.o
 obj-$(CONFIG_PMIC_S5M8767) += s5m8767.o
 

drivers/power/pmic/act8846.c

@@ -0,0 +1,90 @@
+/*
+ * 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/act8846_pmic.h>
+#include <power/pmic.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static const struct pmic_child_info pmic_children_info[] = {
+	{ .prefix = "REG", .driver = "act8846_reg"},
+	{ },
+};
+
+static int act8846_reg_count(struct udevice *dev)
+{
+	return ACT8846_NUM_OF_REGS;
+}
+
+static int act8846_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 act8846_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;
+}
+
+static int act8846_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;
+}
+
+static struct dm_pmic_ops act8846_ops = {
+	.reg_count = act8846_reg_count,
+	.read = act8846_read,
+	.write = act8846_write,
+};
+
+static const struct udevice_id act8846_ids[] = {
+	{ .compatible = "active-semi,act8846" },
+	{ }
+};
+
+U_BOOT_DRIVER(pmic_act8846) = {
+	.name = "act8846 pmic",
+	.id = UCLASS_PMIC,
+	.of_match = act8846_ids,
+	.bind = act8846_bind,
+	.ops = &act8846_ops,
+};

include/power/act8846_pmic.h

@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2015 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef _PMIC_ACT8846_H_
+#define _PMIC_ACT8846_H_
+
+#include <asm/gpio.h>
+
+#define ACT8846_NUM_OF_REGS	12
+
+#define BUCK_VOL_MASK 0x3f
+#define LDO_VOL_MASK 0x3f
+
+#define BUCK_EN_MASK 0x80
+#define LDO_EN_MASK 0x80
+
+#define VOL_MIN_IDX 0x00
+#define VOL_MAX_IDX 0x3f
+
+struct  act8846_reg_table {
+	char	*name;
+	char	reg_ctl;
+	char	reg_vol;
+};
+
+struct pmic_act8846 {
+	struct pmic *pmic;
+	int node;	/*device tree node*/
+	struct gpio_desc pwr_hold;
+	struct udevice *dev;
+};
+
+#endif