diff options
Diffstat (limited to 'drivers/spmi/spmi.c')
| -rw-r--r-- | drivers/spmi/spmi.c | 574 | 
1 files changed, 574 insertions, 0 deletions
diff --git a/drivers/spmi/spmi.c b/drivers/spmi/spmi.c new file mode 100644 index 00000000000..3b5780710d5 --- /dev/null +++ b/drivers/spmi/spmi.c @@ -0,0 +1,574 @@ +/* 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, +}; + +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, +	.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");  | 
