dm: pmic: add s2mps11 PMIC I/O driver

This driver allows I/O operations on the Samsung S2MPS11 PMIC,
which provides lots of LDO/BUCK outputs.

To enable it, update defconfig with:
- CONFIG_PMIC_S2MPS11
and additional, if were not defined:
- CONFIG_CMD_PMIC
- CONFIG_ERRNO_STR

The binding info: doc/device-tree-bindings/pmic/s2mps11.txt

Signed-off-by: Przemyslaw Marczak <p.marczak@samsung.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Anand Moon <linux.amoon@gmail.com>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>

drivers/power/pmic/Kconfig

@@ -33,6 +33,20 @@ 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_S2MPS11
+	bool "Enable Driver Model for PMIC Samsung S2MPS11"
+	depends on DM_PMIC
+	---help---
+	The Samsung S2MPS11 PMIC provides:
+	 - 38 adjustable LDO regulators
+	 - 9 High-Efficiency Buck Converters
+	 - 1 BuckBoost Converter
+	 - RTC with two alarms
+	 - Backup battery charger
+	 - I2C Configuration Interface
+	This driver provides access to I/O interface only.
+	Binding info: doc/device-tree-bindings/pmic/s2mps11.txt
+
 config DM_PMIC_SANDBOX
 	bool "Enable Driver Model for emulated Sandbox PMIC "
 	depends on DM_PMIC

drivers/power/pmic/Makefile

@@ -8,6 +8,7 @@
 obj-$(CONFIG_DM_PMIC) += pmic-uclass.o
 obj-$(CONFIG_DM_PMIC_MAX77686) += max77686.o
 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_TPS65090) += tps65090.o

drivers/power/pmic/s2mps11.c

@@ -0,0 +1,62 @@
+/*
+ *  Copyright (C) 2015 Samsung Electronics
+ *  Przemyslaw Marczak  <p.marczak@samsung.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <fdtdec.h>
+#include <errno.h>
+#include <dm.h>
+#include <i2c.h>
+#include <power/pmic.h>
+#include <power/s2mps11.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static int s2mps11_reg_count(struct udevice *dev)
+{
+	return S2MPS11_REG_COUNT;
+}
+
+static int s2mps11_write(struct udevice *dev, uint reg, const uint8_t *buff,
+			 int len)
+{
+	int ret;
+
+	ret = dm_i2c_write(dev, reg, buff, len);
+	if (ret)
+		error("write error to device: %p register: %#x!", dev, reg);
+
+	return ret;
+}
+
+static int s2mps11_read(struct udevice *dev, uint reg, uint8_t *buff, int len)
+{
+	int ret;
+
+	ret = dm_i2c_read(dev, reg, buff, len);
+	if (ret)
+		error("read error from device: %p register: %#x!", dev, reg);
+
+	return ret;
+}
+
+static struct dm_pmic_ops s2mps11_ops = {
+	.reg_count = s2mps11_reg_count,
+	.read = s2mps11_read,
+	.write = s2mps11_write,
+};
+
+static const struct udevice_id s2mps11_ids[] = {
+	{ .compatible = "samsung,s2mps11-pmic" },
+	{ }
+};
+
+U_BOOT_DRIVER(pmic_s2mps11) = {
+	.name = "s2mps11_pmic",
+	.id = UCLASS_PMIC,
+	.of_match = s2mps11_ids,
+	.ops = &s2mps11_ops,
+};