Commit 5a86bf34 authored by Kenneth Heitke's avatar Kenneth Heitke Committed by Greg Kroah-Hartman
Browse files

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: default avatarKenneth Heitke <kheitke@codeaurora.org>
Signed-off-by: default avatarMichael Bohan <mbohan@codeaurora.org>
Signed-off-by: default avatarJosh Cartwright <joshc@codeaurora.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a2a720e1

drivers/Kconfig

+2 −0
Original line number Diff line number Diff line
@@ -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

+1 −0
Original line number Diff line number Diff line
@@ -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 → 100644
+9 −0
Original line number Diff line number Diff line 
#

# 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 → 100644
+4 −0
Original line number Diff line number Diff line 
#

# Makefile for kernel SPMI framework.

#

obj-$(CONFIG_SPMI)	+= spmi.o

drivers/spmi/spmi.c

0 → 100644
+609 −0
Original line number Diff line number Diff line 
/* 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.

 */

#include <linux/kernel.h>

#include <linux/errno.h>

#include <linux/idr.h>

#include <linux/slab.h>

#include <linux/module.h>

#include <linux/of.h>

#include <linux/of_device.h>

#include <linux/platform_device.h>

#include <linux/spmi.h>

#include <linux/module.h>

#include <linux/pm_runtime.h>



#include <dt-bindings/spmi/spmi.h>



static DEFINE_IDA(ctrl_ida);



static void spmi_dev_release(struct device *dev)

{

	struct spmi_device *sdev = to_spmi_device(dev);

	kfree(sdev);

}



static const struct device_type spmi_dev_type = {

	.release	= spmi_dev_release,

};



static void spmi_ctrl_release(struct device *dev)

{

	struct spmi_controller *ctrl = to_spmi_controller(dev);

	ida_simple_remove(&ctrl_ida, ctrl->nr);

	kfree(ctrl);

}



static const struct device_type spmi_ctrl_type = {

	.release	= spmi_ctrl_release,

};



#ifdef CONFIG_PM_RUNTIME

static int spmi_runtime_suspend(struct device *dev)

{

	struct spmi_device *sdev = to_spmi_device(dev);

	int err;



	err = pm_generic_runtime_suspend(dev);

	if (err)

		return err;



	return spmi_command_sleep(sdev);

}



static int spmi_runtime_resume(struct device *dev)

{

	struct spmi_device *sdev = to_spmi_device(dev);

	int err;



	err = spmi_command_wakeup(sdev);

	if (err)

		return err;



	return pm_generic_runtime_resume(dev);

}

#endif



static const struct dev_pm_ops spmi_pm_ops = {

	SET_RUNTIME_PM_OPS(

		spmi_runtime_suspend,

		spmi_runtime_resume,

		NULL

	)

};



static int spmi_device_match(struct device *dev, struct device_driver *drv)

{

	if (of_driver_match_device(dev, drv))

		return 1;



	if (drv->name)

		return strncmp(dev_name(dev), drv->name,

			       SPMI_NAME_SIZE) == 0;



	return 0;

}



/**

 * spmi_device_add() - add a device previously constructed via spmi_device_alloc()

 * @sdev:	spmi_device to be added

 */

int spmi_device_add(struct spmi_device *sdev)

{

	struct spmi_controller *ctrl = sdev->ctrl;

	int err;



	dev_set_name(&sdev->dev, "%d-%02x", ctrl->nr, sdev->usid);



	err = device_add(&sdev->dev);

	if (err < 0) {

		dev_err(&sdev->dev, "Can't add %s, status %d\n",

			dev_name(&sdev->dev), err);

		goto err_device_add;

	}



	dev_dbg(&sdev->dev, "device %s registered\n", dev_name(&sdev->dev));



err_device_add:

	return err;

}

EXPORT_SYMBOL_GPL(spmi_device_add);



/**

 * spmi_device_remove(): remove an SPMI device

 * @sdev:	spmi_device to be removed

 */

void spmi_device_remove(struct spmi_device *sdev)

{

	device_unregister(&sdev->dev);

}

EXPORT_SYMBOL_GPL(spmi_device_remove);



static inline int

spmi_cmd(struct spmi_controller *ctrl, u8 opcode, u8 sid)

{

	if (!ctrl || !ctrl->cmd || ctrl->dev.type != &spmi_ctrl_type)

		return -EINVAL;



	return ctrl->cmd(ctrl, opcode, sid);

}



static inline int spmi_read_cmd(struct spmi_controller *ctrl, u8 opcode,

				u8 sid, u16 addr, u8 *buf, size_t len)

{

	if (!ctrl || !ctrl->read_cmd || ctrl->dev.type != &spmi_ctrl_type)

		return -EINVAL;



	return ctrl->read_cmd(ctrl, opcode, sid, addr, buf, len);

}



static inline int spmi_write_cmd(struct spmi_controller *ctrl, u8 opcode,

				 u8 sid, u16 addr, const u8 *buf, size_t len)

{

	if (!ctrl || !ctrl->write_cmd || ctrl->dev.type != &spmi_ctrl_type)

		return -EINVAL;



	return ctrl->write_cmd(ctrl, opcode, sid, addr, buf, len);

}



/**

 * spmi_register_read() - register read

 * @sdev:	SPMI device.

 * @addr:	slave register address (5-bit address).

 * @buf:	buffer to be populated with data from the Slave.

 *

 * Reads 1 byte of data from a Slave device register.

 */

int spmi_register_read(struct spmi_device *sdev, u8 addr, u8 *buf)

{

	/* 5-bit register address */

	if (addr > 0x1F)

		return -EINVAL;



	return spmi_read_cmd(sdev->ctrl, SPMI_CMD_READ, sdev->usid, addr,

			     buf, 1);

}

EXPORT_SYMBOL_GPL(spmi_register_read);



/**

 * spmi_ext_register_read() - extended register read

 * @sdev:	SPMI device.

 * @addr:	slave register address (8-bit address).

 * @buf:	buffer to be populated with data from the Slave.

 * @len:	the request number of bytes to read (up to 16 bytes).

 *

 * Reads up to 16 bytes of data from the extended register space on a

 * Slave device.

 */

int spmi_ext_register_read(struct spmi_device *sdev, u8 addr, u8 *buf,

			   size_t len)

{

	/* 8-bit register address, up to 16 bytes */

	if (len == 0 || len > 16)

		return -EINVAL;



	return spmi_read_cmd(sdev->ctrl, SPMI_CMD_EXT_READ, sdev->usid, addr,

			     buf, len);

}

EXPORT_SYMBOL_GPL(spmi_ext_register_read);



/**

 * spmi_ext_register_readl() - extended register read long

 * @sdev:	SPMI device.

 * @addr:	slave register address (16-bit address).

 * @buf:	buffer to be populated with data from the Slave.

 * @len:	the request number of bytes to read (up to 8 bytes).

 *

 * Reads up to 8 bytes of data from the extended register space on a

 * Slave device using 16-bit address.

 */

int spmi_ext_register_readl(struct spmi_device *sdev, u16 addr, u8 *buf,

			    size_t len)

{

	/* 16-bit register address, up to 8 bytes */

	if (len == 0 || len > 8)

		return -EINVAL;



	return spmi_read_cmd(sdev->ctrl, SPMI_CMD_EXT_READL, sdev->usid, addr,

			     buf, len);

}

EXPORT_SYMBOL_GPL(spmi_ext_register_readl);



/**

 * spmi_register_write() - register write

 * @sdev:	SPMI device

 * @addr:	slave register address (5-bit address).

 * @data:	buffer containing the data to be transferred to the Slave.

 *

 * Writes 1 byte of data to a Slave device register.

 */

int spmi_register_write(struct spmi_device *sdev, u8 addr, u8 data)

{

	/* 5-bit register address */

	if (addr > 0x1F)

		return -EINVAL;



	return spmi_write_cmd(sdev->ctrl, SPMI_CMD_WRITE, sdev->usid, addr,

			      &data, 1);

}

EXPORT_SYMBOL_GPL(spmi_register_write);



/**

 * spmi_register_zero_write() - register zero write

 * @sdev:	SPMI device.

 * @data:	the data to be written to register 0 (7-bits).

 *

 * Writes data to register 0 of the Slave device.

 */

int spmi_register_zero_write(struct spmi_device *sdev, u8 data)

{

	return spmi_write_cmd(sdev->ctrl, SPMI_CMD_ZERO_WRITE, sdev->usid, 0,

			      &data, 1);

}

EXPORT_SYMBOL_GPL(spmi_register_zero_write);



/**

 * spmi_ext_register_write() - extended register write

 * @sdev:	SPMI device.

 * @addr:	slave register address (8-bit address).

 * @buf:	buffer containing the data to be transferred to the Slave.

 * @len:	the request number of bytes to read (up to 16 bytes).

 *

 * Writes up to 16 bytes of data to the extended register space of a

 * Slave device.

 */

int spmi_ext_register_write(struct spmi_device *sdev, u8 addr, const u8 *buf,

			    size_t len)

{

	/* 8-bit register address, up to 16 bytes */

	if (len == 0 || len > 16)

		return -EINVAL;



	return spmi_write_cmd(sdev->ctrl, SPMI_CMD_EXT_WRITE, sdev->usid, addr,

			      buf, len);

}

EXPORT_SYMBOL_GPL(spmi_ext_register_write);



/**

 * spmi_ext_register_writel() - extended register write long

 * @sdev:	SPMI device.

 * @addr:	slave register address (16-bit address).

 * @buf:	buffer containing the data to be transferred to the Slave.

 * @len:	the request number of bytes to read (up to 8 bytes).

 *

 * Writes up to 8 bytes of data to the extended register space of a

 * Slave device using 16-bit address.

 */

int spmi_ext_register_writel(struct spmi_device *sdev, u16 addr, const u8 *buf,

			     size_t len)

{

	/* 4-bit Slave Identifier, 16-bit register address, up to 8 bytes */

	if (len == 0 || len > 8)

		return -EINVAL;



	return spmi_write_cmd(sdev->ctrl, SPMI_CMD_EXT_WRITEL, sdev->usid,

			      addr, buf, len);

}

EXPORT_SYMBOL_GPL(spmi_ext_register_writel);



/**

 * spmi_command_reset() - sends RESET command to the specified slave

 * @sdev:	SPMI device.

 *

 * The Reset command initializes the Slave and forces all registers to

 * their reset values. The Slave shall enter the STARTUP state after

 * receiving a Reset command.

 */

int spmi_command_reset(struct spmi_device *sdev)

{

	return spmi_cmd(sdev->ctrl, SPMI_CMD_RESET, sdev->usid);

}

EXPORT_SYMBOL_GPL(spmi_command_reset);



/**

 * spmi_command_sleep() - sends SLEEP command to the specified SPMI device

 * @sdev:	SPMI device.

 *

 * The Sleep command causes the Slave to enter the user defined SLEEP state.

 */

int spmi_command_sleep(struct spmi_device *sdev)

{

	return spmi_cmd(sdev->ctrl, SPMI_CMD_SLEEP, sdev->usid);

}

EXPORT_SYMBOL_GPL(spmi_command_sleep);



/**

 * spmi_command_wakeup() - sends WAKEUP command to the specified SPMI device

 * @sdev:	SPMI device.

 *

 * The Wakeup command causes the Slave to move from the SLEEP state to

 * the ACTIVE state.

 */

int spmi_command_wakeup(struct spmi_device *sdev)

{

	return spmi_cmd(sdev->ctrl, SPMI_CMD_WAKEUP, sdev->usid);

}

EXPORT_SYMBOL_GPL(spmi_command_wakeup);



/**

 * spmi_command_shutdown() - sends SHUTDOWN command to the specified SPMI device

 * @sdev:	SPMI device.

 *

 * The Shutdown command causes the Slave to enter the SHUTDOWN state.

 */

int spmi_command_shutdown(struct spmi_device *sdev)

{

	return spmi_cmd(sdev->ctrl, SPMI_CMD_SHUTDOWN, sdev->usid);

}

EXPORT_SYMBOL_GPL(spmi_command_shutdown);



static int spmi_drv_probe(struct device *dev)

{

	const struct spmi_driver *sdrv = to_spmi_driver(dev->driver);

	struct spmi_device *sdev = to_spmi_device(dev);

	int err;



	/* Ensure the slave is in ACTIVE state */

	err = spmi_command_wakeup(sdev);

	if (err)

		goto fail_wakeup;



	pm_runtime_get_noresume(dev);

	pm_runtime_set_active(dev);

	pm_runtime_enable(dev);



	err = sdrv->probe(sdev);

	if (err)

		goto fail_probe;



	return 0;



fail_probe:

	pm_runtime_disable(dev);

	pm_runtime_set_suspended(dev);

	pm_runtime_put_noidle(dev);

fail_wakeup:

	return err;

}



static int spmi_drv_remove(struct device *dev)

{

	const struct spmi_driver *sdrv = to_spmi_driver(dev->driver);



	pm_runtime_get_sync(dev);

	sdrv->remove(to_spmi_device(dev));

	pm_runtime_put_noidle(dev);



	pm_runtime_disable(dev);

	pm_runtime_set_suspended(dev);

	pm_runtime_put_noidle(dev);

	return 0;

}



static struct bus_type spmi_bus_type = {

	.name		= "spmi",

	.match		= spmi_device_match,

	.pm		= &spmi_pm_ops,

	.probe		= spmi_drv_probe,

	.remove		= spmi_drv_remove,

};



/**

 * spmi_controller_alloc() - Allocate a new SPMI device

 * @ctrl:	associated controller

 *

 * Caller is responsible for either calling spmi_device_add() to add the

 * newly allocated controller, or calling spmi_device_put() to discard it.

 */

struct spmi_device *spmi_device_alloc(struct spmi_controller *ctrl)

{

	struct spmi_device *sdev;



	sdev = kzalloc(sizeof(*sdev), GFP_KERNEL);

	if (!sdev)

		return NULL;



	sdev->ctrl = ctrl;

	device_initialize(&sdev->dev);

	sdev->dev.parent = &ctrl->dev;

	sdev->dev.bus = &spmi_bus_type;

	sdev->dev.type = &spmi_dev_type;

	return sdev;

}

EXPORT_SYMBOL_GPL(spmi_device_alloc);



/**

 * spmi_controller_alloc() - Allocate a new SPMI controller

 * @parent:	parent device

 * @size:	size of private data

 *

 * Caller is responsible for either calling spmi_controller_add() to add the

 * newly allocated controller, or calling spmi_controller_put() to discard it.

 * The allocated private data region may be accessed via

 * spmi_controller_get_drvdata()

 */

struct spmi_controller *spmi_controller_alloc(struct device *parent,

					      size_t size)

{

	struct spmi_controller *ctrl;

	int id;



	if (WARN_ON(!parent))

		return NULL;



	ctrl = kzalloc(sizeof(*ctrl) + size, GFP_KERNEL);

	if (!ctrl)

		return NULL;



	device_initialize(&ctrl->dev);

	ctrl->dev.type = &spmi_ctrl_type;

	ctrl->dev.bus = &spmi_bus_type;

	ctrl->dev.parent = parent;

	ctrl->dev.of_node = parent->of_node;

	spmi_controller_set_drvdata(ctrl, &ctrl[1]);



	id = ida_simple_get(&ctrl_ida, 0, 0, GFP_KERNEL);

	if (id < 0) {

		dev_err(parent,

			"unable to allocate SPMI controller identifier.\n");

		spmi_controller_put(ctrl);

		return NULL;

	}



	ctrl->nr = id;

	dev_set_name(&ctrl->dev, "spmi-%d", id);



	dev_dbg(&ctrl->dev, "allocated controller 0x%p id %d\n", ctrl, id);

	return ctrl;

}

EXPORT_SYMBOL_GPL(spmi_controller_alloc);



static void of_spmi_register_devices(struct spmi_controller *ctrl)

{

	struct device_node *node;

	int err;



	if (!ctrl->dev.of_node)

		return;



	for_each_available_child_of_node(ctrl->dev.of_node, node) {

		struct spmi_device *sdev;

		u32 reg[2];



		dev_dbg(&ctrl->dev, "adding child %s\n", node->full_name);



		err = of_property_read_u32_array(node, "reg", reg, 2);

		if (err) {

			dev_err(&ctrl->dev,

				"node %s err (%d) does not have 'reg' property\n",

				node->full_name, err);

			continue;

		}



		if (reg[1] != SPMI_USID) {

			dev_err(&ctrl->dev,

				"node %s contains unsupported 'reg' entry\n",

				node->full_name);

			continue;

		}



		if (reg[0] >= SPMI_MAX_SLAVE_ID) {

			dev_err(&ctrl->dev,

				"invalid usid on node %s\n",

				node->full_name);

			continue;

		}



		dev_dbg(&ctrl->dev, "read usid %02x\n", reg[0]);



		sdev = spmi_device_alloc(ctrl);

		if (!sdev)

			continue;



		sdev->dev.of_node = node;

		sdev->usid = (u8) reg[0];



		err = spmi_device_add(sdev);

		if (err) {

			dev_err(&sdev->dev,

				"failure adding device. status %d\n", err);

			spmi_device_put(sdev);

		}

	}

}



/**

 * spmi_controller_add() - Add an SPMI controller

 * @ctrl:	controller to be registered.

 *

 * Register a controller previously allocated via spmi_controller_alloc() with

 * the SPMI core.

 */

int spmi_controller_add(struct spmi_controller *ctrl)

{

	int ret;



	/* Can't register until after driver model init */

	if (WARN_ON(!spmi_bus_type.p))

		return -EAGAIN;



	ret = device_add(&ctrl->dev);

	if (ret)

		return ret;



	if (IS_ENABLED(CONFIG_OF))

		of_spmi_register_devices(ctrl);



	dev_dbg(&ctrl->dev, "spmi-%d registered: dev:%p\n",

		ctrl->nr, &ctrl->dev);



	return 0;

};

EXPORT_SYMBOL_GPL(spmi_controller_add);



/* Remove a device associated with a controller */

static int spmi_ctrl_remove_device(struct device *dev, void *data)

{

	struct spmi_device *spmidev = to_spmi_device(dev);

	if (dev->type == &spmi_dev_type)

		spmi_device_remove(spmidev);

	return 0;

}



/**

 * spmi_controller_remove(): remove an SPMI controller

 * @ctrl:	controller to remove

 *

 * Remove a SPMI controller.  Caller is responsible for calling

 * spmi_controller_put() to discard the allocated controller.

 */

void spmi_controller_remove(struct spmi_controller *ctrl)

{

	int dummy;



	if (!ctrl)

		return;



	dummy = device_for_each_child(&ctrl->dev, NULL,

				      spmi_ctrl_remove_device);

	device_del(&ctrl->dev);

}

EXPORT_SYMBOL_GPL(spmi_controller_remove);



/**

 * spmi_driver_register() - Register client driver with SPMI core

 * @sdrv:	client driver to be associated with client-device.

 *

 * This API will register the client driver with the SPMI framework.

 * It is typically called from the driver's module-init function.

 */

int spmi_driver_register(struct spmi_driver *sdrv)

{

	sdrv->driver.bus = &spmi_bus_type;

	return driver_register(&sdrv->driver);

}

EXPORT_SYMBOL_GPL(spmi_driver_register);



static void __exit spmi_exit(void)

{

	bus_unregister(&spmi_bus_type);

}

module_exit(spmi_exit);



static int __init spmi_init(void)

{

	return bus_register(&spmi_bus_type);

}

postcore_initcall(spmi_init);



MODULE_LICENSE("GPL v2");

MODULE_DESCRIPTION("SPMI module");

MODULE_ALIAS("platform:spmi");

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