[PATCH 1/7] mfd: add imx syscon driver based on regmap

[Dong Aisheng <b29396-KZfg59tc24xl57MIdRCFDg@public.gmane.org>]

From: Dong Aisheng <dong.aisheng-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>

Add regmap based imx syscon driver.
This is usually used for access misc bits in registers which does not belong
to a specific module, for example, IOMUXC GPR and ANATOP.
With this driver, we provide a standard API for client driver to call to
access registers which are registered into syscon.

Signed-off-by: Dong Aisheng <dong.aisheng-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
---
Currently it's just simply for IMX, however the driver really is not too
much imx specific.
If people want, we probably could extend it to support other platforms too.
---
 .../devicetree/bindings/mfd/imx-syscon.txt         |   11 +
 drivers/mfd/Kconfig                                |    8 +
 drivers/mfd/Makefile                               |    1 +
 drivers/mfd/imx-syscon.c                           |  193 ++++++++++++++++++++
 include/linux/mfd/imx-syscon.h                     |   22 +++
 5 files changed, 235 insertions(+), 0 deletions(-)

diff --git a/Documentation/devicetree/bindings/mfd/imx-syscon.txt b/Documentation/devicetree/bindings/mfd/imx-syscon.txt
new file mode 100644
index 0000000..4a72994
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/imx-syscon.txt
@@ -0,0 +1,11 @@
+* Freescale IMX System Controller Registers R/W driver
+
+Required properties:
+- compatible: Should contain "fsl,imx-syscon".
+- reg: the register range can be access from imx-syscon
+
+Examples:
+gpr: iomuxc-gpr@020e0000 {
+	compatible = "fsl,imx6q-iomuxc", "fsl,imx-syscon";
+	reg = <0x020e0000 0x38>;
+};
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index b1a1462..20a050e 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -993,6 +993,14 @@ config MFD_ANATOP
 	  MFD controller. This controller embeds regulator and
 	  thermal devices for Freescale i.MX platforms.
 
+config MFD_IMX_SYSCON
+        bool "Freescale i.MX System Controller Register R/W Based on Regmap"
+        depends on ARCH_MXC
+        select REGMAP_MMIO
+        help
+          Select this option to enable access Freescale i.MX system control
+	  registers like iomuxc gpr and anatop via regmap.
+
 config MFD_PALMAS
 	bool "Support for the TI Palmas series chips"
 	select MFD_CORE
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 79dd22d..82c7ee1 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -131,4 +131,5 @@ obj-$(CONFIG_MFD_PALMAS)	+= palmas.o
 obj-$(CONFIG_MFD_RC5T583)	+= rc5t583.o rc5t583-irq.o
 obj-$(CONFIG_MFD_SEC_CORE)	+= sec-core.o sec-irq.o
 obj-$(CONFIG_MFD_ANATOP)	+= anatop-mfd.o
+obj-$(CONFIG_MFD_IMX_SYSCON)	+= imx-syscon.o
 obj-$(CONFIG_MFD_LM3533)	+= lm3533-core.o lm3533-ctrlbank.o
diff --git a/drivers/mfd/imx-syscon.c b/drivers/mfd/imx-syscon.c
new file mode 100644
index 0000000..141b456
--- /dev/null
+++ b/drivers/mfd/imx-syscon.c
@@ -0,0 +1,193 @@
+/*
+ * Freescale IMX System Control Driver
+ *
+ * Copyright (C) 2012 Freescale Semiconductor, Inc.
+ * Copyright (C) 2012 Linaro Ltd.
+ *
+ * Author: Dong Aisheng <dong.aisheng-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+static struct platform_driver imx_syscon_driver;
+
+struct imx_syscon {
+	struct device *dev;
+	void __iomem *base;
+	struct regmap *regmap;
+};
+
+static int imx_syscon_match(struct device *dev, void *data)
+{
+	struct imx_syscon *syscon = dev_get_drvdata(dev);
+	struct device_node *dn = data;
+
+	return (syscon->dev->of_node == dn) ? 1 : 0;
+}
+
+int imx_syscon_write(struct device_node *np, u32 reg, u32 val)
+{
+	struct device *dev;
+	struct imx_syscon *syscon;
+	int ret = 0;
+
+	dev = driver_find_device(&imx_syscon_driver.driver, NULL, np,
+				 imx_syscon_match);
+	if (!dev)
+		return -EPROBE_DEFER;
+
+	syscon = dev_get_drvdata(dev);
+	ret = regmap_write(syscon->regmap, reg, val);
+	if (ret)
+		dev_err(dev, "failed to write regmap(%s) reg 0x%x (%d)\n",
+			np->name, reg, ret);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(imx_syscon_write);
+
+int imx_syscon_read(struct device_node *np, u32 reg, u32 *val)
+{
+	struct device *dev;
+	struct imx_syscon *syscon;
+	int ret = 0;
+
+	dev = driver_find_device(&imx_syscon_driver.driver, NULL, np,
+				 imx_syscon_match);
+	if (!dev)
+		return -EPROBE_DEFER;
+
+	syscon = dev_get_drvdata(dev);
+	ret = regmap_read(syscon->regmap, reg, val);
+	if (ret)
+		dev_err(dev, "failed to read regmap(%s) reg 0x%x (%d)\n",
+			np->name, reg, ret);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(imx_syscon_read);
+
+int imx_syscon_update_bits(struct device_node *np, u32 reg,
+					u32 mask, u32 val)
+{
+	struct device *dev;
+	struct imx_syscon *syscon;
+	int ret = 0;
+
+	dev = driver_find_device(&imx_syscon_driver.driver, NULL, np,
+				 imx_syscon_match);
+	if (!dev)
+		return -EPROBE_DEFER;
+
+	syscon = dev_get_drvdata(dev);
+	ret = regmap_update_bits(syscon->regmap, reg, mask, val);
+	if (ret)
+		dev_err(dev, "failed to update regmap(%s) reg 0x%x (%d)\n",
+			np->name, reg, ret);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(imx_syscon_update_bits);
+
+static const struct of_device_id of_imx_syscon_match[] = {
+	{ .compatible = "fsl,imx-syscon", },
+	{ },
+};
+
+static struct regmap_config imx_syscon_regmap_config = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+};
+
+static int __devinit imx_syscon_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct imx_syscon *syscon;
+	struct resource res;
+	int ret;
+
+	if (!np)
+		return -ENOENT;
+
+	syscon = devm_kzalloc(&pdev->dev, sizeof(struct imx_syscon),
+			    GFP_KERNEL);
+	if (!syscon)
+		return -ENOMEM;
+
+	syscon->base = of_iomap(np, 0);
+	if (!syscon->base)
+		return -EADDRNOTAVAIL;
+
+	ret = of_address_to_resource(np, 0, &res);
+	if (ret)
+		return ret;
+
+	imx_syscon_regmap_config.max_register = res.end - res.start - 3;
+	syscon->regmap = devm_regmap_init_mmio(&pdev->dev, syscon->base,
+					&imx_syscon_regmap_config);
+	if (IS_ERR(syscon->regmap)) {
+		dev_err(&pdev->dev, "regmap init failed\n");
+		return PTR_ERR(syscon->regmap);
+	}
+
+	regcache_cache_only(syscon->regmap, false);
+
+	dev_info(dev, "syscon regmap start 0x%x end 0x%x registered\n",
+		res.start, res.end);
+
+	syscon->dev = &pdev->dev;
+	platform_set_drvdata(pdev, syscon);
+
+	return 0;
+}
+
+static int __devexit imx_syscon_remove(struct platform_device *pdev)
+{
+	struct imx_syscon *syscon;
+
+	syscon = platform_get_drvdata(pdev);
+	iounmap(syscon->base);
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+static struct platform_driver imx_syscon_driver = {
+	.driver = {
+		.name = "imx-syscon",
+		.owner = THIS_MODULE,
+		.of_match_table = of_imx_syscon_match,
+	},
+	.probe		= imx_syscon_probe,
+	.remove		= imx_syscon_remove,
+};
+
+static int __init imx_syscon_init(void)
+{
+	return platform_driver_register(&imx_syscon_driver);
+}
+postcore_initcall(imx_syscon_init);
+
+static void __exit anatop_exit(void)
+{
+	platform_driver_unregister(&imx_syscon_driver);
+}
+module_exit(anatop_exit);
+
+MODULE_AUTHOR("Dong Aisheng <dong.aisheng-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>");
+MODULE_DESCRIPTION("Freescale IMX System Control driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/mfd/imx-syscon.h b/include/linux/mfd/imx-syscon.h
new file mode 100644
index 0000000..be8b6db
--- /dev/null
+++ b/include/linux/mfd/imx-syscon.h
@@ -0,0 +1,22 @@
+/*
+ * Freescale IMX System Control Driver
+ *
+ * Copyright (C) 2012 Freescale Semiconductor, Inc.
+ * Copyright (C) 2012 Linaro Ltd.
+ *
+ * Author: Dong Aisheng <dong.aisheng-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef __LINUX_MFD_IMX_SYSCON_H__
+#define __LINUX_MFD_IMX_SYSCON_H__
+
+extern int imx_syscon_write(struct device_node *np, u32 reg, u32 val);
+extern int imx_syscon_read(struct device_node *np, u32 reg, u32 *val);
+extern int imx_syscon_update_bits(struct device_node *np, u32 reg,
+					u32 mask, u32 val);
+#endif /* __LINUX_MFD_IMX_SYSCON_H__ */
-- 
1.7.0.4