[RFC PATCH 05/11] mfd: omap: control: core system control driver

[Eduardo Valentin <eduardo.valentin@ti.com>]

This patch introduces a MFD core device driver for
OMAP system control module.

The control module allows software control of
various static modes supported by the device. It is
composed of two control submodules: general control
module and device (padconfiguration) control
module.

In this patch, the children defined are for:
. USB-phy pin control
. Bangap temperature sensor

Device driver is probed with postcore_initcall.
However, as some of the APIs exposed by this driver
may be needed in very early init phase, an early init
class is also available: "early_omap_control".

Signed-off-by: J Keerthy <j-keerthy@ti.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
---
 .../devicetree/bindings/mfd/omap_control.txt       |   44 ++++
 arch/arm/mach-omap2/Kconfig                        |    1 +
 arch/arm/plat-omap/Kconfig                         |    3 +
 drivers/mfd/Kconfig                                |    9 +
 drivers/mfd/Makefile                               |    1 +
 drivers/mfd/omap-control-core.c                    |  211 ++++++++++++++++++++
 include/linux/mfd/omap_control.h                   |   69 +++++++
 7 files changed, 338 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/mfd/omap_control.txt
 create mode 100644 drivers/mfd/omap-control-core.c
 create mode 100644 include/linux/mfd/omap_control.h

diff --git a/Documentation/devicetree/bindings/mfd/omap_control.txt b/Documentation/devicetree/bindings/mfd/omap_control.txt
new file mode 100644
index 0000000..46d5e7e
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/omap_control.txt
@@ -0,0 +1,44 @@
+* Texas Instrument OMAP System Control Module (SCM) bindings
+
+The control module allows software control of various static modes supported by
+the device. The control module controls the settings of various device  modules
+through register configuration and internal signals. It also controls  the  pad
+configuration, pin functional multiplexing, and the routing of internal signals
+(such as PRCM  signals or DMA requests)  to output pins configured for hardware
+observability.
+
+Required properties:
+- compatible : Should be:
+  - "ti,omap3-control" for OMAP3 support
+  - "ti,omap4-control" for OMAP4 support
+  - "ti,omap5-control" for OMAP5 support
+
+OMAP specific properties:
+- ti,hwmods: Name of the hwmod associated to the control module:
+  Should be "ctrl_module_core";
+
+Sub-nodes:
+- bandgap : contains the bandgap node
+
+  The bindings details of individual bandgap device can be found in:
+  Documentation/devicetree/bindings/thermal/omap_bandgap.txt
+
+- usb : contains the usb phy pin control node
+
+  The only required property for this child is:
+    - compatible = "ti,omap4-control-usb";
+
+Examples:
+
+ctrl_module_core: ctrl_module_core@4a002000 {
+	compatible = "ti,omap4-control";
+	ti,hwmods = "ctrl_module_core";
+	bandgap {
+		compatible = "ti,omap4460-bandgap";
+		interrupts = <0 126 4>; /* talert */
+		ti,tshut-gpio = <86>; /* tshut */
+	};
+	usb {
+		compatible = "ti,omap4-usb-phy";
+	};
+};
diff --git a/arch/arm/mach-omap2/Kconfig b/arch/arm/mach-omap2/Kconfig
index a2b946d..7dfe5e1 100644
--- a/arch/arm/mach-omap2/Kconfig
+++ b/arch/arm/mach-omap2/Kconfig
@@ -52,6 +52,7 @@ config ARCH_OMAP4
 	select PL310_ERRATA_727915
 	select ARM_ERRATA_720789
 	select ARCH_HAS_OPP
+	select ARCH_HAS_CONTROL_MODULE
 	select PM_OPP if PM
 	select USB_ARCH_HAS_EHCI if USB_SUPPORT
 	select ARM_CPU_SUSPEND if PM
diff --git a/arch/arm/plat-omap/Kconfig b/arch/arm/plat-omap/Kconfig
index ad95c7a..222dbad 100644
--- a/arch/arm/plat-omap/Kconfig
+++ b/arch/arm/plat-omap/Kconfig
@@ -5,6 +5,9 @@ menu "TI OMAP Common Features"
 config ARCH_OMAP_OTG
 	bool
 
+config ARCH_HAS_CONTROL_MODULE
+	bool
+
 choice
 	prompt "OMAP System Type"
 	default ARCH_OMAP2PLUS
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 11e4438..25a66d8 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -795,6 +795,15 @@ config MFD_WL1273_CORE
 	  driver connects the radio-wl1273 V4L2 module and the wl1273
 	  audio codec.
 
+config MFD_OMAP_CONTROL
+	bool "Texas Instruments OMAP System control module"
+	depends on ARCH_HAS_CONTROL_MODULE
+	help
+	  This is the core driver for system control module. This driver
+	  is responsible for creating the control module mfd child,
+	  like USB-pin control, pin muxing, MMC-pbias and DDR IO dynamic
+	  change for off mode.
+
 config MFD_OMAP_USB_HOST
 	bool "Support OMAP USBHS core driver"
 	depends on USB_EHCI_HCD_OMAP || USB_OHCI_HCD_OMAP3
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 05fa538..00f99d6 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -106,6 +106,7 @@ obj-$(CONFIG_MFD_TPS6586X)	+= tps6586x.o
 obj-$(CONFIG_MFD_VX855)		+= vx855.o
 obj-$(CONFIG_MFD_WL1273_CORE)	+= wl1273-core.o
 obj-$(CONFIG_MFD_CS5535)	+= cs5535-mfd.o
+obj-$(CONFIG_MFD_OMAP_CONTROL)	+= omap-control-core.o
 obj-$(CONFIG_MFD_OMAP_USB_HOST)	+= omap-usb-host.o
 obj-$(CONFIG_MFD_PM8921_CORE) 	+= pm8921-core.o
 obj-$(CONFIG_MFD_PM8XXX_IRQ) 	+= pm8xxx-irq.o
diff --git a/drivers/mfd/omap-control-core.c b/drivers/mfd/omap-control-core.c
new file mode 100644
index 0000000..7d8d408
--- /dev/null
+++ b/drivers/mfd/omap-control-core.c
@@ -0,0 +1,211 @@
+/*
+ * OMAP system control module driver file
+ *
+ * Copyright (C) 2011-2012 Texas Instruments Incorporated - http://www.ti.com/
+ * Contacts:
+ * Based on original code written by:
+ *    J Keerthy <j-keerthy@ti.com>
+ *    Moiz Sonasath <m-sonasath@ti.com>
+ * MFD clean up and re-factoring:
+ *    Eduardo Valentin <eduardo.valentin@ti.com>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/export.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/of_platform.h>
+#include <linux/of_address.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/omap_control.h>
+
+static struct omap_control *omap_control_module;
+
+/**
+ * omap_control_readl: Read a single omap control module register.
+ *
+ * @dev: device to read from.
+ * @reg: register to read.
+ * @val: output with register value.
+ *
+ * returns 0 on success or -EINVAL in case struct device is invalid.
+ */
+int omap_control_readl(struct device *dev, u32 reg, u32 *val)
+{
+	struct omap_control *omap_control = dev_get_drvdata(dev);
+
+	if (!omap_control)
+		return -EINVAL;
+
+	*val = readl(omap_control->base + reg);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(omap_control_readl);
+
+/**
+ * omap_control_writel: Write a single omap control module register.
+ *
+ * @dev: device to read from.
+ * @val: value to write.
+ * @reg: register to write to.
+ *
+ * returns 0 on success or -EINVAL in case struct device is invalid.
+ */
+int omap_control_writel(struct device *dev, u32 val, u32 reg)
+{
+	struct omap_control *omap_control = dev_get_drvdata(dev);
+	unsigned long flags;
+
+	if (!omap_control)
+		return -EINVAL;
+
+	spin_lock_irqsave(&omap_control->reg_lock, flags);
+	writel(val, omap_control->base + reg);
+	spin_unlock_irqrestore(&omap_control->reg_lock, flags);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(omap_control_writel);
+
+/**
+ * omap_control_get: returns the control module device pinter
+ *
+ * The modules which has to use control module API's to read or write should
+ * call this API to get the control module device pointer.
+ */
+struct device *omap_control_get(void)
+{
+	unsigned long flags;
+
+	if (!omap_control_module)
+		return ERR_PTR(-ENODEV);
+
+	spin_lock_irqsave(&omap_control_module->reg_lock, flags);
+	omap_control_module->use_count++;
+	spin_unlock_irqrestore(&omap_control_module->reg_lock, flags);
+
+	return omap_control_module->dev;
+}
+EXPORT_SYMBOL_GPL(omap_control_get);
+
+/**
+ * omap_control_put: returns the control module device pinter
+ *
+ * The modules which has to use control module API's to read or write should
+ * call this API to get the control module device pointer.
+ */
+void omap_control_put(struct device *dev)
+{
+	struct omap_control *omap_control = dev_get_drvdata(dev);
+	unsigned long flags;
+
+	if (!omap_control)
+		return;
+
+	spin_lock_irqsave(&omap_control->reg_lock, flags);
+	omap_control->use_count--;
+	spin_unlock_irqrestore(&omap_control_module->reg_lock, flags);
+}
+EXPORT_SYMBOL_GPL(omap_control_put);
+
+static const struct of_device_id of_omap_control_match[] = {
+	{ .compatible = "ti,omap3-control", },
+	{ .compatible = "ti,omap4-control", },
+	{ .compatible = "ti,omap5-control", },
+	{ },
+};
+
+static int __devinit omap_control_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	void __iomem *base;
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct omap_control *omap_control;
+
+	omap_control = devm_kzalloc(dev, sizeof(*omap_control), GFP_KERNEL);
+	if (!omap_control) {
+		dev_err(dev, "not enough memory for omap_control\n");
+		return -ENOMEM;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "missing memory base resource\n");
+		return -EINVAL;
+	}
+
+	base = devm_request_and_ioremap(dev, res);
+	if (!base) {
+		dev_err(dev, "ioremap failed\n");
+		return -EADDRNOTAVAIL;
+	}
+
+	omap_control->base = base;
+	omap_control->dev = dev;
+	spin_lock_init(&omap_control->reg_lock);
+
+	platform_set_drvdata(pdev, omap_control);
+	omap_control_module = omap_control;
+
+	return of_platform_populate(np, of_omap_control_match, NULL, dev);
+}
+
+static int __devexit omap_control_remove(struct platform_device *pdev)
+{
+	struct omap_control *omap_control = platform_get_drvdata(pdev);
+
+	spin_lock(&omap_control->reg_lock);
+	if (omap_control->use_count > 0) {
+		spin_unlock(&omap_control->reg_lock);
+		dev_err(&pdev->dev, "device removed while still being used\n");
+		return -EBUSY;
+	}
+	spin_unlock(&omap_control->reg_lock);
+
+	iounmap(omap_control->base);
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+static struct platform_driver omap_control_driver = {
+	.probe			= omap_control_probe,
+	.remove			= __devexit_p(omap_control_remove),
+	.driver = {
+		.name		= "omap-control-core",
+		.owner		= THIS_MODULE,
+		.of_match_table	= of_omap_control_match,
+	},
+};
+
+static int __init omap_control_init(void)
+{
+	return platform_driver_register(&omap_control_driver);
+}
+postcore_initcall_sync(omap_control_init);
+
+static void __exit omap_control_exit(void)
+{
+	platform_driver_unregister(&omap_control_driver);
+}
+module_exit(omap_control_exit);
+early_platform_init("early_omap_control", &omap_control_driver);
+
+MODULE_DESCRIPTION("OMAP system control module driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:omap-control-core");
+MODULE_AUTHOR("Texas Instruments Inc.");
diff --git a/include/linux/mfd/omap_control.h b/include/linux/mfd/omap_control.h
new file mode 100644
index 0000000..7a33eda
--- /dev/null
+++ b/include/linux/mfd/omap_control.h
@@ -0,0 +1,69 @@
+/*
+ * OMAP system control module header file
+ *
+ * Copyright (C) 2011-2012 Texas Instruments Incorporated - http://www.ti.com/
+ * Contact:
+ *   J Keerthy <j-keerthy@ti.com>
+ *   Moiz Sonasath <m-sonasath@ti.com>
+ *   Abraham, Kishon Vijay <kishon@ti.com>
+ *   Eduardo Valentin <eduardo.valentin@ti.com>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ */
+
+#ifndef __DRIVERS_OMAP_CONTROL_H
+#define __DRIVERS_OMAP_CONTROL_H
+
+#include <linux/err.h>
+
+/**
+ * struct system control module - scm device structure
+ * @dev: device pointer
+ * @base: Base of the temp I/O
+ * @reg_lock: protect omap_control structure
+ * @use_count: track API users
+ */
+struct omap_control {
+	struct device		*dev;
+	void __iomem		*base;
+	/* protect this data structure and register access */
+	spinlock_t		reg_lock;
+	int			use_count;
+};
+
+/* TODO: Add helpers for 16bit and byte access */
+#ifdef CONFIG_MFD_OMAP_CONTROL
+extern int omap_control_readl(struct device *dev, u32 reg, u32 *val);
+extern int omap_control_writel(struct device *dev, u32 val, u32 reg);
+extern struct device *omap_control_get(void);
+extern void omap_control_put(struct device *dev);
+#else
+static inline int omap_control_readl(struct device *dev, u32 reg, u32 *val)
+{
+	return 0;
+}
+
+static inline int omap_control_writel(struct device *dev, u32 val, u32 reg)
+{
+	return 0;
+}
+
+static inline struct device *omap_control_get(void)
+{
+	return ERR_PTR(-EINVAL);
+}
+
+static inline void omap_control_put(struct device *dev)
+{
+}
+#endif
+
+#endif /* __DRIVERS_OMAP_CONTROL_H */
-- 
1.7.7.1.488.ge8e1c