spmi: Linux driver framework for SPMI

System Power Management Interface (SPMI) is a specification
developed by the MIPI (Mobile Industry Process Interface) Alliance
optimized for the real time control of Power Management ICs (PMIC).

SPMI is a two-wire serial interface that supports up to 4 master
devices and up to 16 logical slaves.

The framework supports message APIs, multiple busses (1 controller
per bus) and multiple clients/slave devices per controller.

Signed-off-by: Kenneth Heitke <kheitke@codeaurora.org>
Signed-off-by: Michael Bohan <mbohan@codeaurora.org>
Signed-off-by: Josh Cartwright <joshc@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/Kconfig

@@ -52,6 +52,8 @@ source "drivers/i2c/Kconfig"
 
 source "drivers/spi/Kconfig"
 
+source "drivers/spmi/Kconfig"
+
 source "drivers/hsi/Kconfig"
 
 source "drivers/pps/Kconfig"

drivers/Makefile

@@ -66,6 +66,7 @@ obj-$(CONFIG_ATA)		+= ata/
 obj-$(CONFIG_TARGET_CORE)	+= target/
 obj-$(CONFIG_MTD)		+= mtd/
 obj-$(CONFIG_SPI)		+= spi/
+obj-$(CONFIG_SPMI)		+= spmi/
 obj-y				+= hsi/
 obj-y				+= net/
 obj-$(CONFIG_ATM)		+= atm/

drivers/spmi/Kconfig

@@ -0,0 +1,9 @@
+#
+# SPMI driver configuration
+#
+menuconfig SPMI
+	tristate "SPMI support"
+	help
+	  SPMI (System Power Management Interface) is a two-wire
+	  serial interface between baseband and application processors
+	  and Power Management Integrated Circuits (PMIC).

drivers/spmi/Makefile

@@ -0,0 +1,4 @@
+#
+# Makefile for kernel SPMI framework.
+#
+obj-$(CONFIG_SPMI)	+= spmi.o

include/dt-bindings/spmi/spmi.h

@@ -0,0 +1,18 @@
+/* Copyright (c) 2013, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only 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 __DT_BINDINGS_SPMI_H
+#define __DT_BINDINGS_SPMI_H
+
+#define SPMI_USID	0
+#define SPMI_GSID	1
+
+#endif

include/linux/mod_devicetable.h

@@ -432,6 +432,14 @@ struct spi_device_id {
 	kernel_ulong_t driver_data;	/* Data private to the driver */
 };
 
+#define SPMI_NAME_SIZE	32
+#define SPMI_MODULE_PREFIX "spmi:"
+
+struct spmi_device_id {
+	char name[SPMI_NAME_SIZE];
+	kernel_ulong_t driver_data;	/* Data private to the driver */
+};
+
 /* dmi */
 enum dmi_field {
 	DMI_NONE,

include/linux/spmi.h

@@ -0,0 +1,191 @@
+/* Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only 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 _LINUX_SPMI_H
+#define _LINUX_SPMI_H
+
+#include <linux/types.h>
+#include <linux/device.h>
+#include <linux/mod_devicetable.h>
+
+/* Maximum slave identifier */
+#define SPMI_MAX_SLAVE_ID		16
+
+/* SPMI Commands */
+#define SPMI_CMD_EXT_WRITE		0x00
+#define SPMI_CMD_RESET			0x10
+#define SPMI_CMD_SLEEP			0x11
+#define SPMI_CMD_SHUTDOWN		0x12
+#define SPMI_CMD_WAKEUP			0x13
+#define SPMI_CMD_AUTHENTICATE		0x14
+#define SPMI_CMD_MSTR_READ		0x15
+#define SPMI_CMD_MSTR_WRITE		0x16
+#define SPMI_CMD_TRANSFER_BUS_OWNERSHIP	0x1A
+#define SPMI_CMD_DDB_MASTER_READ	0x1B
+#define SPMI_CMD_DDB_SLAVE_READ		0x1C
+#define SPMI_CMD_EXT_READ		0x20
+#define SPMI_CMD_EXT_WRITEL		0x30
+#define SPMI_CMD_EXT_READL		0x38
+#define SPMI_CMD_WRITE			0x40
+#define SPMI_CMD_READ			0x60
+#define SPMI_CMD_ZERO_WRITE		0x80
+
+/**
+ * struct spmi_device - Basic representation of an SPMI device
+ * @dev:	Driver model representation of the device.
+ * @ctrl:	SPMI controller managing the bus hosting this device.
+ * @usid:	This devices' Unique Slave IDentifier.
+ */
+struct spmi_device {
+	struct device		dev;
+	struct spmi_controller	*ctrl;
+	u8			usid;
+};
+
+static inline struct spmi_device *to_spmi_device(struct device *d)
+{
+	return container_of(d, struct spmi_device, dev);
+}
+
+static inline void *spmi_device_get_drvdata(const struct spmi_device *sdev)
+{
+	return dev_get_drvdata(&sdev->dev);
+}
+
+static inline void spmi_device_set_drvdata(struct spmi_device *sdev, void *data)
+{
+	dev_set_drvdata(&sdev->dev, data);
+}
+
+struct spmi_device *spmi_device_alloc(struct spmi_controller *ctrl);
+
+static inline void spmi_device_put(struct spmi_device *sdev)
+{
+	if (sdev)
+		put_device(&sdev->dev);
+}
+
+int spmi_device_add(struct spmi_device *sdev);
+
+void spmi_device_remove(struct spmi_device *sdev);
+
+/**
+ * struct spmi_controller - interface to the SPMI master controller
+ * @dev:	Driver model representation of the device.
+ * @nr:		board-specific number identifier for this controller/bus
+ * @cmd:	sends a non-data command sequence on the SPMI bus.
+ * @read_cmd:	sends a register read command sequence on the SPMI bus.
+ * @write_cmd:	sends a register write command sequence on the SPMI bus.
+ */
+struct spmi_controller {
+	struct device		dev;
+	unsigned int		nr;
+	int	(*cmd)(struct spmi_controller *ctrl, u8 opcode, u8 sid);
+	int	(*read_cmd)(struct spmi_controller *ctrl, u8 opcode,
+			    u8 sid, u16 addr, u8 *buf, size_t len);
+	int	(*write_cmd)(struct spmi_controller *ctrl, u8 opcode,
+			     u8 sid, u16 addr, const u8 *buf, size_t len);
+};
+
+static inline struct spmi_controller *to_spmi_controller(struct device *d)
+{
+	return container_of(d, struct spmi_controller, dev);
+}
+
+static inline
+void *spmi_controller_get_drvdata(const struct spmi_controller *ctrl)
+{
+	return dev_get_drvdata(&ctrl->dev);
+}
+
+static inline void spmi_controller_set_drvdata(struct spmi_controller *ctrl,
+					       void *data)
+{
+	dev_set_drvdata(&ctrl->dev, data);
+}
+
+struct spmi_controller *spmi_controller_alloc(struct device *parent,
+					      size_t size);
+
+/**
+ * spmi_controller_put() - decrement controller refcount
+ * @ctrl	SPMI controller.
+ */
+static inline void spmi_controller_put(struct spmi_controller *ctrl)
+{
+	if (ctrl)
+		put_device(&ctrl->dev);
+}
+
+int spmi_controller_add(struct spmi_controller *ctrl);
+void spmi_controller_remove(struct spmi_controller *ctrl);
+
+/**
+ * struct spmi_driver - SPMI slave device driver
+ * @driver:	SPMI device drivers should initialize name and owner field of
+ *		this structure.
+ * @probe:	binds this driver to a SPMI device.
+ * @remove:	unbinds this driver from the SPMI device.
+ * @shutdown:	standard shutdown callback used during powerdown/halt.
+ * @suspend:	standard suspend callback used during system suspend.
+ * @resume:	standard resume callback used during system resume.
+ *
+ * If PM runtime support is desired for a slave, a device driver can call
+ * pm_runtime_put() from their probe() routine (and a balancing
+ * pm_runtime_get() in remove()).  PM runtime support for a slave is
+ * implemented by issuing a SLEEP command to the slave on runtime_suspend(),
+ * transitioning the slave into the SLEEP state.  On runtime_resume(), a WAKEUP
+ * command is sent to the slave to bring it back to ACTIVE.
+ */
+struct spmi_driver {
+	struct device_driver driver;
+	int	(*probe)(struct spmi_device *sdev);
+	void	(*remove)(struct spmi_device *sdev);
+};
+
+static inline struct spmi_driver *to_spmi_driver(struct device_driver *d)
+{
+	return container_of(d, struct spmi_driver, driver);
+}
+
+int spmi_driver_register(struct spmi_driver *sdrv);
+
+/**
+ * spmi_driver_unregister() - unregister an SPMI client driver
+ * @sdrv:	the driver to unregister
+ */
+static inline void spmi_driver_unregister(struct spmi_driver *sdrv)
+{
+	if (sdrv)
+		driver_unregister(&sdrv->driver);
+}
+
+#define module_spmi_driver(__spmi_driver) \
+	module_driver(__spmi_driver, spmi_driver_register, \
+			spmi_driver_unregister)
+
+int spmi_register_read(struct spmi_device *sdev, u8 addr, u8 *buf);
+int spmi_ext_register_read(struct spmi_device *sdev, u8 addr, u8 *buf,
+			   size_t len);
+int spmi_ext_register_readl(struct spmi_device *sdev, u16 addr, u8 *buf,
+			    size_t len);
+int spmi_register_write(struct spmi_device *sdev, u8 addr, u8 data);
+int spmi_register_zero_write(struct spmi_device *sdev, u8 data);
+int spmi_ext_register_write(struct spmi_device *sdev, u8 addr,
+			    const u8 *buf, size_t len);
+int spmi_ext_register_writel(struct spmi_device *sdev, u16 addr,
+			     const u8 *buf, size_t len);
+int spmi_command_reset(struct spmi_device *sdev);
+int spmi_command_sleep(struct spmi_device *sdev);
+int spmi_command_wakeup(struct spmi_device *sdev);
+int spmi_command_shutdown(struct spmi_device *sdev);
+
+#endif