[PATCH v6 4/6] mfd: Add hi6421 PMIC core driver

[Guodong Xu <guodong.xu@linaro.org>]

This adds driver to support HiSilicon Hi6421 PMIC. Hi6421 includes multi-
functions, such as regulators, codec, ADCs, Coulomb counter, etc.
This driver includes core APIs _only_.

Drivers for individul components, like voltage regulators, are
implemented in corresponding driver directories and files.

Registers in Hi6421 are memory mapped, so using regmap-mmio API.

Signed-off-by: Guodong Xu <guodong.xu@linaro.org>
---
 Documentation/devicetree/bindings/mfd/hi6421.txt |  37 +++++++
 drivers/mfd/Kconfig                              |  13 +++
 drivers/mfd/Makefile                             |   1 +
 drivers/mfd/hi6421-pmic-core.c                   | 117 +++++++++++++++++++++++
 include/linux/mfd/hi6421-pmic.h                  |  39 ++++++++
 5 files changed, 207 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/hi6421.txt
 create mode 100644 drivers/mfd/hi6421-pmic-core.c
 create mode 100644 include/linux/mfd/hi6421-pmic.h

diff --git a/Documentation/devicetree/bindings/mfd/hi6421.txt b/Documentation/devicetree/bindings/mfd/hi6421.txt
new file mode 100644
index 0000000..1512123
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/hi6421.txt
@@ -0,0 +1,37 @@
+* HI6421 Multi-Functional Device (MFD), by HiSilicon Ltd.
+
+Required parent device properties:
+- reg		: register range space of hi6421;
+
+Supported Hi6421 sub-devices include:
+
+Device                     IRQ Names              Supply Names   Description
+------                     ---------              ------------   -----------
+regulators               :                      :              : Regulators
+
+Required child device properties:
+None.
+
+Example:
+	pmic: pmic@c00000 {
+		compatible = "hisilicon,hi6421-pmic";
+		reg = <0xc00000 0x0180>; /* 0x60 << 2 */
+
+		regulators {
+			// supply for MLC NAND/ eMMC
+			hi6421_vout0_reg: hi6421_vout0 {
+				regulator-name = "VOUT0";
+				regulator-min-microvolt = <2850000>;
+				regulator-max-microvolt = <2850000>;
+			};
+
+			// supply for 26M Oscillator
+			hi6421_vout1_reg: hi6421_vout1 {
+				regulator-name = "VOUT1";
+				regulator-min-microvolt = <1700000>;
+				regulator-max-microvolt = <2000000>;
+				regulator-boot-on;
+				regulator-always-on;
+			};
+		};
+       	};
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index de5abf2..347cbf6 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -210,6 +210,19 @@ config MFD_MC13XXX_I2C
 	help
 	  Select this if your MC13xxx is connected via an I2C bus.
 
+config MFD_HI6421_PMIC
+	tristate "HiSilicon Hi6421 PMU/Codec IC"
+	depends on OF
+	select MFD_CORE
+	select REGMAP_MMIO
+	help
+	  This driver supports HiSilicon Hi6421 PMIC. Hi6421 includes multi-
+	  functions, such as regulators, codec, ADCs, Coulomb counter, etc.
+	  This driver includes core APIs _only_. You have to select
+	  individul components like voltage regulators under corresponding
+	  menus in order to enable them.
+	  Memory-mapped I/O is the way to communicate with Hi6421.
+
 config HTC_EGPIO
 	bool "HTC EGPIO support"
 	depends on GPIOLIB && ARM
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index f001487..dc59efd 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -169,6 +169,7 @@ obj-$(CONFIG_MFD_AS3711)	+= as3711.o
 obj-$(CONFIG_MFD_AS3722)	+= as3722.o
 obj-$(CONFIG_MFD_STW481X)	+= stw481x.o
 obj-$(CONFIG_MFD_IPAQ_MICRO)	+= ipaq-micro.o
+obj-$(CONFIG_MFD_HI6421_PMIC)	+= hi6421-pmic-core.o
 
 intel-soc-pmic-objs		:= intel_soc_pmic_core.o intel_soc_pmic_crc.o
 obj-$(CONFIG_INTEL_SOC_PMIC)	+= intel-soc-pmic.o
diff --git a/drivers/mfd/hi6421-pmic-core.c b/drivers/mfd/hi6421-pmic-core.c
new file mode 100644
index 0000000..2be4d3f
--- /dev/null
+++ b/drivers/mfd/hi6421-pmic-core.c
@@ -0,0 +1,117 @@
+/*
+ * Device driver for Hi6421 IC
+ *
+ * Copyright (c) <2011-2014> HiSilicon Technologies Co., Ltd.
+ *              http://www.hisilicon.com
+ * Copyright (c) <2013-2014> Linaro Ltd.
+ *              http://www.linaro.org
+ *
+ * Author: Guodong Xu <guodong.xu@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/mfd/core.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/mfd/hi6421-pmic.h>
+
+static struct of_device_id of_hi6421_pmic_match_tbl[] = {
+	{
+		.compatible = "hisilicon,hi6421-pmic",
+	},
+	{ /* end */ }
+};
+
+static const struct mfd_cell hi6421_devs[] = {
+	{
+		.name = "hi6421-regulator",
+	},
+};
+
+static struct regmap_config hi6421_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 8,
+	.max_register = HI6421_REG_TO_BUS_ADDR(0xFF),
+};
+
+static int hi6421_pmic_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct hi6421_pmic *pmic = NULL;
+	struct resource *res;
+	void __iomem *base;
+	int ret;
+
+	pmic = devm_kzalloc(dev, sizeof(*pmic), GFP_KERNEL);
+	if (!pmic) {
+		dev_err(dev, "cannot allocate hi6421_pmic device info\n");
+		return -ENOMEM;
+	}
+
+	/* get resources */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (unlikely(!res)) {
+		dev_err(&pdev->dev, "Invalid mem resource.\n");
+		return -ENODEV;
+	}
+
+	base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	pmic->regmap = devm_regmap_init_mmio_clk(&pdev->dev, NULL, base,
+						 &hi6421_regmap_config);
+	if (IS_ERR(pmic->regmap)) {
+		dev_err(&pdev->dev, "regmap init failed: %ld\n",
+						PTR_ERR(pmic->regmap));
+		return PTR_ERR(pmic->regmap);
+	}
+
+	pmic->dev = dev;
+	platform_set_drvdata(pdev, pmic);
+
+	/* set over-current protection debounce 8ms*/
+	regmap_update_bits(pmic->regmap, HI6421_OCP_DEB_CTRL_REG,
+		(HI6421_OCP_DEB_SEL_MASK | HI6421_OCP_EN_DEBOUNCE_MASK |
+		 HI6421_OCP_AUTO_STOP_MASK),
+		(HI6421_OCP_DEB_SEL_8MS | HI6421_OCP_EN_DEBOUNCE_ENABLE));
+
+	ret = mfd_add_devices(dev, 0, hi6421_devs,
+			ARRAY_SIZE(hi6421_devs), NULL, 0, NULL);
+
+	return ret;
+}
+
+static int hi6421_pmic_remove(struct platform_device *pdev)
+{
+	mfd_remove_devices(&pdev->dev);
+
+	return 0;
+}
+
+static struct platform_driver hi6421_pmic_driver = {
+	.driver = {
+		.name	= "hi6421_pmic",
+		.owner  = THIS_MODULE,
+		.of_match_table = of_hi6421_pmic_match_tbl,
+	},
+	.probe	= hi6421_pmic_probe,
+	.remove	= hi6421_pmic_remove,
+};
+module_platform_driver(hi6421_pmic_driver);
+
+MODULE_AUTHOR("Guodong Xu <guodong.xu@linaro.org>");
+MODULE_DESCRIPTION("Hi6421 PMIC driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/mfd/hi6421-pmic.h b/include/linux/mfd/hi6421-pmic.h
new file mode 100644
index 0000000..36bcb34
--- /dev/null
+++ b/include/linux/mfd/hi6421-pmic.h
@@ -0,0 +1,39 @@
+/*
+ * Header file for device driver Hi6421 PMIC
+ *
+ * Copyright (c) <2011-2014> HiSilicon Technologies Co., Ltd.
+ *              http://www.hisilicon.com
+ * Copyright (c) <2013-2014> Linaro Ltd.
+ *              http://www.linaro.org
+ *
+ * Author: Guodong Xu <guodong.xu@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef	__HI6421_PMIC_H
+#define	__HI6421_PMIC_H
+
+/* Hi6421 registers are mapped to memory bus in 4 bytes stride */
+#define HI6421_REG_TO_BUS_ADDR(x)	(x << 2)
+
+/* Hi6421 OCP (over current protection) and DEB (debounce) control register */
+#define	HI6421_OCP_DEB_CTRL_REG		HI6421_REG_TO_BUS_ADDR(0x51)
+#define	HI6421_OCP_DEB_SEL_MASK		(0x0C)
+#define HI6421_OCP_DEB_SEL_8MS		(0x00)
+#define HI6421_OCP_DEB_SEL_16MS		(0x04)
+#define HI6421_OCP_DEB_SEL_32MS		(0x08)
+#define HI6421_OCP_DEB_SEL_64MS		(0x0C)
+#define HI6421_OCP_EN_DEBOUNCE_MASK	(0x02)
+#define HI6421_OCP_EN_DEBOUNCE_ENABLE	(0x02)
+#define HI6421_OCP_AUTO_STOP_MASK	(0x01)
+#define HI6421_OCP_AUTO_STOP_ENABLE	(0x01)
+
+struct hi6421_pmic {
+	struct device		*dev;
+	struct regmap		*regmap;
+};
+
+#endif		/* __HI6421_PMIC_H */
-- 
1.9.1