drivers/acpi/sbshc.c - kernel/bruno - Git at Google

 /*
  * SMBus driver for ACPI Embedded Controller (v0.1)
  *
  * Copyright (c) 2007 Alexey Starikovskiy
  *
  * 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 version 2.
  */

 #include <linux/acpi.h>
 #include <linux/wait.h>
 #include <linux/slab.h>
 #include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/interrupt.h>
 #include "sbshc.h"

 #define PREFIX "ACPI: "

 #define ACPI_SMB_HC_CLASS	"smbus_host_ctl"
 #define ACPI_SMB_HC_DEVICE_NAME	"ACPI SMBus HC"

 struct acpi_smb_hc {
 	struct acpi_ec *ec;
 	struct mutex lock;
 	wait_queue_head_t wait;
 	u8 offset;
 	u8 query_bit;
 	smbus_alarm_callback callback;
 	void *context;
 	bool done;
 };

 static int acpi_smbus_hc_add(struct acpi_device *device);
 static int acpi_smbus_hc_remove(struct acpi_device *device);

 static const struct acpi_device_id sbs_device_ids[] = {
 	{"ACPI0001", 0},
 	{"ACPI0005", 0},
 	{"", 0},
 };

 MODULE_DEVICE_TABLE(acpi, sbs_device_ids);

 static struct acpi_driver acpi_smb_hc_driver = {
 	.name = "smbus_hc",
 	.class = ACPI_SMB_HC_CLASS,
 	.ids = sbs_device_ids,
 	.ops = {
 		.add = acpi_smbus_hc_add,
 		.remove = acpi_smbus_hc_remove,
 		},
 };

 union acpi_smb_status {
 	u8 raw;
 	struct {
 		u8 status:5;
 		u8 reserved:1;
 		u8 alarm:1;
 		u8 done:1;
 	} fields;
 };

 enum acpi_smb_status_codes {
 	SMBUS_OK = 0,
 	SMBUS_UNKNOWN_FAILURE = 0x07,
 	SMBUS_DEVICE_ADDRESS_NACK = 0x10,
 	SMBUS_DEVICE_ERROR = 0x11,
 	SMBUS_DEVICE_COMMAND_ACCESS_DENIED = 0x12,
 	SMBUS_UNKNOWN_ERROR = 0x13,
 	SMBUS_DEVICE_ACCESS_DENIED = 0x17,
 	SMBUS_TIMEOUT = 0x18,
 	SMBUS_HOST_UNSUPPORTED_PROTOCOL = 0x19,
 	SMBUS_BUSY = 0x1a,
 	SMBUS_PEC_ERROR = 0x1f,
 };

 enum acpi_smb_offset {
 	ACPI_SMB_PROTOCOL = 0,	/* protocol, PEC */
 	ACPI_SMB_STATUS = 1,	/* status */
 	ACPI_SMB_ADDRESS = 2,	/* address */
 	ACPI_SMB_COMMAND = 3,	/* command */
 	ACPI_SMB_DATA = 4,	/* 32 data registers */
 	ACPI_SMB_BLOCK_COUNT = 0x24,	/* number of data bytes */
 	ACPI_SMB_ALARM_ADDRESS = 0x25,	/* alarm address */
 	ACPI_SMB_ALARM_DATA = 0x26,	/* 2 bytes alarm data */
 };

 static inline int smb_hc_read(struct acpi_smb_hc *hc, u8 address, u8 *data)
 {
 	return ec_read(hc->offset + address, data);
 }

 static inline int smb_hc_write(struct acpi_smb_hc *hc, u8 address, u8 data)
 {
 	return ec_write(hc->offset + address, data);
 }

 static int wait_transaction_complete(struct acpi_smb_hc *hc, int timeout)
 {
 	if (wait_event_timeout(hc->wait, hc->done, msecs_to_jiffies(timeout)))
 		return 0;
 	return -ETIME;
 }

 static int acpi_smbus_transaction(struct acpi_smb_hc *hc, u8 protocol,
 				  u8 address, u8 command, u8 *data, u8 length)
 {
 	int ret = -EFAULT, i;
 	u8 temp, sz = 0;

 	if (!hc) {
 		printk(KERN_ERR PREFIX "host controller is not configured\n");
 		return ret;
 	}

 	mutex_lock(&hc->lock);
 	hc->done = false;
 	if (smb_hc_read(hc, ACPI_SMB_PROTOCOL, &temp))
 		goto end;
 	if (temp) {
 		ret = -EBUSY;
 		goto end;
 	}
 	smb_hc_write(hc, ACPI_SMB_COMMAND, command);
 	if (!(protocol & 0x01)) {
 		smb_hc_write(hc, ACPI_SMB_BLOCK_COUNT, length);
 		for (i = 0; i < length; ++i)
 			smb_hc_write(hc, ACPI_SMB_DATA + i, data[i]);
 	}
 	smb_hc_write(hc, ACPI_SMB_ADDRESS, address << 1);
 	smb_hc_write(hc, ACPI_SMB_PROTOCOL, protocol);
 	/*
 	 * Wait for completion. Save the status code, data size,
 	 * and data into the return package (if required by the protocol).
 	 */
 	ret = wait_transaction_complete(hc, 1000);
 	if (ret || !(protocol & 0x01))
 		goto end;
 	switch (protocol) {
 	case SMBUS_RECEIVE_BYTE:
 	case SMBUS_READ_BYTE:
 		sz = 1;
 		break;
 	case SMBUS_READ_WORD:
 		sz = 2;
 		break;
 	case SMBUS_READ_BLOCK:
 		if (smb_hc_read(hc, ACPI_SMB_BLOCK_COUNT, &sz)) {
 			ret = -EFAULT;
 			goto end;
 		}
 		sz &= 0x1f;
 		break;
 	}
 	for (i = 0; i < sz; ++i)
 		smb_hc_read(hc, ACPI_SMB_DATA + i, &data[i]);
       end:
 	mutex_unlock(&hc->lock);
 	return ret;
 }

 int acpi_smbus_read(struct acpi_smb_hc *hc, u8 protocol, u8 address,
 		    u8 command, u8 *data)
 {
 	return acpi_smbus_transaction(hc, protocol, address, command, data, 0);
 }

 EXPORT_SYMBOL_GPL(acpi_smbus_read);

 int acpi_smbus_write(struct acpi_smb_hc *hc, u8 protocol, u8 address,
 		     u8 command, u8 *data, u8 length)
 {
 	return acpi_smbus_transaction(hc, protocol, address, command, data, length);
 }

 EXPORT_SYMBOL_GPL(acpi_smbus_write);

 int acpi_smbus_register_callback(struct acpi_smb_hc *hc,
 			         smbus_alarm_callback callback, void *context)
 {
 	mutex_lock(&hc->lock);
 	hc->callback = callback;
 	hc->context = context;
 	mutex_unlock(&hc->lock);
 	return 0;
 }

 EXPORT_SYMBOL_GPL(acpi_smbus_register_callback);

 int acpi_smbus_unregister_callback(struct acpi_smb_hc *hc)
 {
 	mutex_lock(&hc->lock);
 	hc->callback = NULL;
 	hc->context = NULL;
 	mutex_unlock(&hc->lock);
 	return 0;
 }

 EXPORT_SYMBOL_GPL(acpi_smbus_unregister_callback);

 static inline void acpi_smbus_callback(void *context)
 {
 	struct acpi_smb_hc *hc = context;
 	if (hc->callback)
 		hc->callback(hc->context);
 }

 static int smbus_alarm(void *context)
 {
 	struct acpi_smb_hc *hc = context;
 	union acpi_smb_status status;
 	u8 address;
 	if (smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw))
 		return 0;
 	/* Check if it is only a completion notify */
 	if (status.fields.done && status.fields.status == SMBUS_OK) {
 		hc->done = true;
 		wake_up(&hc->wait);
 	}
 	if (!status.fields.alarm)
 		return 0;
 	mutex_lock(&hc->lock);
 	smb_hc_read(hc, ACPI_SMB_ALARM_ADDRESS, &address);
 	status.fields.alarm = 0;
 	smb_hc_write(hc, ACPI_SMB_STATUS, status.raw);
 	/* We are only interested in events coming from known devices */
 	switch (address >> 1) {
 		case ACPI_SBS_CHARGER:
 		case ACPI_SBS_MANAGER:
 		case ACPI_SBS_BATTERY:
 			acpi_os_execute(OSL_NOTIFY_HANDLER,
 					acpi_smbus_callback, hc);
 		default:;
 	}
 	mutex_unlock(&hc->lock);
 	return 0;
 }

 typedef int (*acpi_ec_query_func) (void *data);

 extern int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 			      acpi_handle handle, acpi_ec_query_func func,
 			      void *data);

 static int acpi_smbus_hc_add(struct acpi_device *device)
 {
 	int status;
 	unsigned long long val;
 	struct acpi_smb_hc *hc;

 	if (!device)
 		return -EINVAL;

 	status = acpi_evaluate_integer(device->handle, "_EC", NULL, &val);
 	if (ACPI_FAILURE(status)) {
 		printk(KERN_ERR PREFIX "error obtaining _EC.\n");
 		return -EIO;
 	}

 	strcpy(acpi_device_name(device), ACPI_SMB_HC_DEVICE_NAME);
 	strcpy(acpi_device_class(device), ACPI_SMB_HC_CLASS);

 	hc = kzalloc(sizeof(struct acpi_smb_hc), GFP_KERNEL);
 	if (!hc)
 		return -ENOMEM;
 	mutex_init(&hc->lock);
 	init_waitqueue_head(&hc->wait);

 	hc->ec = acpi_driver_data(device->parent);
 	hc->offset = (val >> 8) & 0xff;
 	hc->query_bit = val & 0xff;
 	device->driver_data = hc;

 	acpi_ec_add_query_handler(hc->ec, hc->query_bit, NULL, smbus_alarm, hc);
 	printk(KERN_INFO PREFIX "SBS HC: EC = 0x%p, offset = 0x%0x, query_bit = 0x%0x\n",
 		hc->ec, hc->offset, hc->query_bit);

 	return 0;
 }

 extern void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit);

 static int acpi_smbus_hc_remove(struct acpi_device *device)
 {
 	struct acpi_smb_hc *hc;

 	if (!device)
 		return -EINVAL;

 	hc = acpi_driver_data(device);
 	acpi_ec_remove_query_handler(hc->ec, hc->query_bit);
 	kfree(hc);
 	device->driver_data = NULL;
 	return 0;
 }

 module_acpi_driver(acpi_smb_hc_driver);

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Alexey Starikovskiy");
 MODULE_DESCRIPTION("ACPI SMBus HC driver");
	/*
	* SMBus driver for ACPI Embedded Controller (v0.1)
	*
	* Copyright (c) 2007 Alexey Starikovskiy
	*
	* 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 version 2.
	*/

	#include <linux/acpi.h>
	#include <linux/wait.h>
	#include <linux/slab.h>
	#include <linux/delay.h>
	#include <linux/module.h>
	#include <linux/interrupt.h>
	#include "sbshc.h"

	#define PREFIX "ACPI: "

	#define ACPI_SMB_HC_CLASS "smbus_host_ctl"
	#define ACPI_SMB_HC_DEVICE_NAME "ACPI SMBus HC"

	struct acpi_smb_hc {
	struct acpi_ec *ec;
	struct mutex lock;
	wait_queue_head_t wait;
	u8 offset;
	u8 query_bit;
	smbus_alarm_callback callback;
	void *context;
	bool done;
	};

	static int acpi_smbus_hc_add(struct acpi_device *device);
	static int acpi_smbus_hc_remove(struct acpi_device *device);

	static const struct acpi_device_id sbs_device_ids[] = {
	{"ACPI0001", 0},
	{"ACPI0005", 0},
	{"", 0},
	};

	MODULE_DEVICE_TABLE(acpi, sbs_device_ids);

	static struct acpi_driver acpi_smb_hc_driver = {
	.name = "smbus_hc",
	.class = ACPI_SMB_HC_CLASS,
	.ids = sbs_device_ids,
	.ops = {
	.add = acpi_smbus_hc_add,
	.remove = acpi_smbus_hc_remove,
	},
	};

	union acpi_smb_status {
	u8 raw;
	struct {
	u8 status:5;
	u8 reserved:1;
	u8 alarm:1;
	u8 done:1;
	} fields;
	};

	enum acpi_smb_status_codes {
	SMBUS_OK = 0,
	SMBUS_UNKNOWN_FAILURE = 0x07,
	SMBUS_DEVICE_ADDRESS_NACK = 0x10,
	SMBUS_DEVICE_ERROR = 0x11,
	SMBUS_DEVICE_COMMAND_ACCESS_DENIED = 0x12,
	SMBUS_UNKNOWN_ERROR = 0x13,
	SMBUS_DEVICE_ACCESS_DENIED = 0x17,
	SMBUS_TIMEOUT = 0x18,
	SMBUS_HOST_UNSUPPORTED_PROTOCOL = 0x19,
	SMBUS_BUSY = 0x1a,
	SMBUS_PEC_ERROR = 0x1f,
	};

	enum acpi_smb_offset {
	ACPI_SMB_PROTOCOL = 0, /* protocol, PEC */
	ACPI_SMB_STATUS = 1, /* status */
	ACPI_SMB_ADDRESS = 2, /* address */
	ACPI_SMB_COMMAND = 3, /* command */
	ACPI_SMB_DATA = 4, /* 32 data registers */
	ACPI_SMB_BLOCK_COUNT = 0x24, /* number of data bytes */
	ACPI_SMB_ALARM_ADDRESS = 0x25, /* alarm address */
	ACPI_SMB_ALARM_DATA = 0x26, /* 2 bytes alarm data */
	};

	static inline int smb_hc_read(struct acpi_smb_hc hc, u8 address, u8 data)
	{
	return ec_read(hc->offset + address, data);
	}

	static inline int smb_hc_write(struct acpi_smb_hc *hc, u8 address, u8 data)
	{
	return ec_write(hc->offset + address, data);
	}

	static int wait_transaction_complete(struct acpi_smb_hc *hc, int timeout)
	{
	if (wait_event_timeout(hc->wait, hc->done, msecs_to_jiffies(timeout)))
	return 0;
	return -ETIME;
	}

	static int acpi_smbus_transaction(struct acpi_smb_hc *hc, u8 protocol,
	u8 address, u8 command, u8 *data, u8 length)
	{
	int ret = -EFAULT, i;
	u8 temp, sz = 0;

	if (!hc) {
	printk(KERN_ERR PREFIX "host controller is not configured\n");
	return ret;
	}

	mutex_lock(&hc->lock);
	hc->done = false;
	if (smb_hc_read(hc, ACPI_SMB_PROTOCOL, &temp))
	goto end;
	if (temp) {
	ret = -EBUSY;
	goto end;
	}
	smb_hc_write(hc, ACPI_SMB_COMMAND, command);
	if (!(protocol & 0x01)) {
	smb_hc_write(hc, ACPI_SMB_BLOCK_COUNT, length);
	for (i = 0; i < length; ++i)
	smb_hc_write(hc, ACPI_SMB_DATA + i, data[i]);
	}
	smb_hc_write(hc, ACPI_SMB_ADDRESS, address << 1);
	smb_hc_write(hc, ACPI_SMB_PROTOCOL, protocol);
	/*
	* Wait for completion. Save the status code, data size,
	* and data into the return package (if required by the protocol).
	*/
	ret = wait_transaction_complete(hc, 1000);
	if (ret \|\| !(protocol & 0x01))
	goto end;
	switch (protocol) {
	case SMBUS_RECEIVE_BYTE:
	case SMBUS_READ_BYTE:
	sz = 1;
	break;
	case SMBUS_READ_WORD:
	sz = 2;
	break;
	case SMBUS_READ_BLOCK:
	if (smb_hc_read(hc, ACPI_SMB_BLOCK_COUNT, &sz)) {
	ret = -EFAULT;
	goto end;
	}
	sz &= 0x1f;
	break;
	}
	for (i = 0; i < sz; ++i)
	smb_hc_read(hc, ACPI_SMB_DATA + i, &data[i]);
	end:
	mutex_unlock(&hc->lock);
	return ret;
	}

	int acpi_smbus_read(struct acpi_smb_hc *hc, u8 protocol, u8 address,
	u8 command, u8 *data)
	{
	return acpi_smbus_transaction(hc, protocol, address, command, data, 0);
	}

	EXPORT_SYMBOL_GPL(acpi_smbus_read);

	int acpi_smbus_write(struct acpi_smb_hc *hc, u8 protocol, u8 address,
	u8 command, u8 *data, u8 length)
	{
	return acpi_smbus_transaction(hc, protocol, address, command, data, length);
	}

	EXPORT_SYMBOL_GPL(acpi_smbus_write);

	int acpi_smbus_register_callback(struct acpi_smb_hc *hc,
	smbus_alarm_callback callback, void *context)
	{
	mutex_lock(&hc->lock);
	hc->callback = callback;
	hc->context = context;
	mutex_unlock(&hc->lock);
	return 0;
	}

	EXPORT_SYMBOL_GPL(acpi_smbus_register_callback);

	int acpi_smbus_unregister_callback(struct acpi_smb_hc *hc)
	{
	mutex_lock(&hc->lock);
	hc->callback = NULL;
	hc->context = NULL;
	mutex_unlock(&hc->lock);
	return 0;
	}

	EXPORT_SYMBOL_GPL(acpi_smbus_unregister_callback);

	static inline void acpi_smbus_callback(void *context)
	{
	struct acpi_smb_hc *hc = context;
	if (hc->callback)
	hc->callback(hc->context);
	}

	static int smbus_alarm(void *context)
	{
	struct acpi_smb_hc *hc = context;
	union acpi_smb_status status;
	u8 address;
	if (smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw))
	return 0;
	/* Check if it is only a completion notify */
	if (status.fields.done && status.fields.status == SMBUS_OK) {
	hc->done = true;
	wake_up(&hc->wait);
	}
	if (!status.fields.alarm)
	return 0;
	mutex_lock(&hc->lock);
	smb_hc_read(hc, ACPI_SMB_ALARM_ADDRESS, &address);
	status.fields.alarm = 0;
	smb_hc_write(hc, ACPI_SMB_STATUS, status.raw);
	/* We are only interested in events coming from known devices */
	switch (address >> 1) {
	case ACPI_SBS_CHARGER:
	case ACPI_SBS_MANAGER:
	case ACPI_SBS_BATTERY:
	acpi_os_execute(OSL_NOTIFY_HANDLER,
	acpi_smbus_callback, hc);
	default:;
	}
	mutex_unlock(&hc->lock);
	return 0;
	}

	typedef int (acpi_ec_query_func) (void data);

	extern int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
	acpi_handle handle, acpi_ec_query_func func,
	void *data);

	static int acpi_smbus_hc_add(struct acpi_device *device)
	{
	int status;
	unsigned long long val;
	struct acpi_smb_hc *hc;

	if (!device)
	return -EINVAL;

	status = acpi_evaluate_integer(device->handle, "_EC", NULL, &val);
	if (ACPI_FAILURE(status)) {
	printk(KERN_ERR PREFIX "error obtaining _EC.\n");
	return -EIO;
	}

	strcpy(acpi_device_name(device), ACPI_SMB_HC_DEVICE_NAME);
	strcpy(acpi_device_class(device), ACPI_SMB_HC_CLASS);

	hc = kzalloc(sizeof(struct acpi_smb_hc), GFP_KERNEL);
	if (!hc)
	return -ENOMEM;
	mutex_init(&hc->lock);
	init_waitqueue_head(&hc->wait);

	hc->ec = acpi_driver_data(device->parent);
	hc->offset = (val >> 8) & 0xff;
	hc->query_bit = val & 0xff;
	device->driver_data = hc;

	acpi_ec_add_query_handler(hc->ec, hc->query_bit, NULL, smbus_alarm, hc);
	printk(KERN_INFO PREFIX "SBS HC: EC = 0x%p, offset = 0x%0x, query_bit = 0x%0x\n",
	hc->ec, hc->offset, hc->query_bit);

	return 0;
	}

	extern void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit);

	static int acpi_smbus_hc_remove(struct acpi_device *device)
	{
	struct acpi_smb_hc *hc;

	if (!device)
	return -EINVAL;

	hc = acpi_driver_data(device);
	acpi_ec_remove_query_handler(hc->ec, hc->query_bit);
	kfree(hc);
	device->driver_data = NULL;
	return 0;
	}

	module_acpi_driver(acpi_smb_hc_driver);

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Alexey Starikovskiy");
	MODULE_DESCRIPTION("ACPI SMBus HC driver");