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v6.2
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3    i2c-isch.c - Linux kernel driver for Intel SCH chipset SMBus
  4    - Based on i2c-piix4.c
  5    Copyright (c) 1998 - 2002 Frodo Looijaard <frodol@dds.nl> and
  6    Philip Edelbrock <phil@netroedge.com>
  7    - Intel SCH support
  8    Copyright (c) 2007 - 2008 Jacob Jun Pan <jacob.jun.pan@intel.com>
  9
 
 
 
 
 
 
 
 
 
 
 
 
 10*/
 11
 12/*
 13   Supports:
 14	Intel SCH chipsets (AF82US15W, AF82US15L, AF82UL11L)
 15   Note: we assume there can only be one device, with one SMBus interface.
 16*/
 17
 18#include <linux/module.h>
 19#include <linux/platform_device.h>
 20#include <linux/kernel.h>
 21#include <linux/delay.h>
 22#include <linux/stddef.h>
 23#include <linux/ioport.h>
 24#include <linux/i2c.h>
 25#include <linux/io.h>
 
 26
 27/* SCH SMBus address offsets */
 28#define SMBHSTCNT	(0 + sch_smba)
 29#define SMBHSTSTS	(1 + sch_smba)
 30#define SMBHSTCLK	(2 + sch_smba)
 31#define SMBHSTADD	(4 + sch_smba) /* TSA */
 32#define SMBHSTCMD	(5 + sch_smba)
 33#define SMBHSTDAT0	(6 + sch_smba)
 34#define SMBHSTDAT1	(7 + sch_smba)
 35#define SMBBLKDAT	(0x20 + sch_smba)
 36
 37/* Other settings */
 38#define MAX_RETRIES	5000
 39
 40/* I2C constants */
 41#define SCH_QUICK		0x00
 42#define SCH_BYTE		0x01
 43#define SCH_BYTE_DATA		0x02
 44#define SCH_WORD_DATA		0x03
 45#define SCH_BLOCK_DATA		0x05
 46
 47static unsigned short sch_smba;
 48static struct i2c_adapter sch_adapter;
 49static int backbone_speed = 33000; /* backbone speed in kHz */
 50module_param(backbone_speed, int, S_IRUSR | S_IWUSR);
 51MODULE_PARM_DESC(backbone_speed, "Backbone speed in kHz, (default = 33000)");
 52
 53/*
 54 * Start the i2c transaction -- the i2c_access will prepare the transaction
 55 * and this function will execute it.
 56 * return 0 for success and others for failure.
 57 */
 58static int sch_transaction(void)
 59{
 60	int temp;
 61	int result = 0;
 62	int retries = 0;
 63
 64	dev_dbg(&sch_adapter.dev, "Transaction (pre): CNT=%02x, CMD=%02x, "
 65		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb(SMBHSTCNT),
 66		inb(SMBHSTCMD), inb(SMBHSTADD), inb(SMBHSTDAT0),
 67		inb(SMBHSTDAT1));
 68
 69	/* Make sure the SMBus host is ready to start transmitting */
 70	temp = inb(SMBHSTSTS) & 0x0f;
 71	if (temp) {
 72		/* Can not be busy since we checked it in sch_access */
 73		if (temp & 0x01) {
 74			dev_dbg(&sch_adapter.dev, "Completion (%02x). "
 75				"Clear...\n", temp);
 76		}
 77		if (temp & 0x06) {
 78			dev_dbg(&sch_adapter.dev, "SMBus error (%02x). "
 79				"Resetting...\n", temp);
 80		}
 81		outb(temp, SMBHSTSTS);
 82		temp = inb(SMBHSTSTS) & 0x0f;
 83		if (temp) {
 84			dev_err(&sch_adapter.dev,
 85				"SMBus is not ready: (%02x)\n", temp);
 86			return -EAGAIN;
 87		}
 88	}
 89
 90	/* start the transaction by setting bit 4 */
 91	outb(inb(SMBHSTCNT) | 0x10, SMBHSTCNT);
 92
 93	do {
 94		usleep_range(100, 200);
 95		temp = inb(SMBHSTSTS) & 0x0f;
 96	} while ((temp & 0x08) && (retries++ < MAX_RETRIES));
 97
 98	/* If the SMBus is still busy, we give up */
 99	if (retries > MAX_RETRIES) {
100		dev_err(&sch_adapter.dev, "SMBus Timeout!\n");
101		result = -ETIMEDOUT;
102	}
103	if (temp & 0x04) {
104		result = -EIO;
105		dev_dbg(&sch_adapter.dev, "Bus collision! SMBus may be "
106			"locked until next hard reset. (sorry!)\n");
107		/* Clock stops and slave is stuck in mid-transmission */
108	} else if (temp & 0x02) {
109		result = -EIO;
110		dev_err(&sch_adapter.dev, "Error: no response!\n");
111	} else if (temp & 0x01) {
112		dev_dbg(&sch_adapter.dev, "Post complete!\n");
113		outb(temp, SMBHSTSTS);
114		temp = inb(SMBHSTSTS) & 0x07;
115		if (temp & 0x06) {
116			/* Completion clear failed */
117			dev_dbg(&sch_adapter.dev, "Failed reset at end of "
118				"transaction (%02x), Bus error!\n", temp);
119		}
120	} else {
121		result = -ENXIO;
122		dev_dbg(&sch_adapter.dev, "No such address.\n");
123	}
124	dev_dbg(&sch_adapter.dev, "Transaction (post): CNT=%02x, CMD=%02x, "
125		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb(SMBHSTCNT),
126		inb(SMBHSTCMD), inb(SMBHSTADD), inb(SMBHSTDAT0),
127		inb(SMBHSTDAT1));
128	return result;
129}
130
131/*
132 * This is the main access entry for i2c-sch access
133 * adap is i2c_adapter pointer, addr is the i2c device bus address, read_write
134 * (0 for read and 1 for write), size is i2c transaction type and data is the
135 * union of transaction for data to be transferred or data read from bus.
136 * return 0 for success and others for failure.
137 */
138static s32 sch_access(struct i2c_adapter *adap, u16 addr,
139		 unsigned short flags, char read_write,
140		 u8 command, int size, union i2c_smbus_data *data)
141{
142	int i, len, temp, rc;
143
144	/* Make sure the SMBus host is not busy */
145	temp = inb(SMBHSTSTS) & 0x0f;
146	if (temp & 0x08) {
147		dev_dbg(&sch_adapter.dev, "SMBus busy (%02x)\n", temp);
148		return -EAGAIN;
149	}
150	temp = inw(SMBHSTCLK);
151	if (!temp) {
152		/*
153		 * We can't determine if we have 33 or 25 MHz clock for
154		 * SMBus, so expect 33 MHz and calculate a bus clock of
155		 * 100 kHz. If we actually run at 25 MHz the bus will be
156		 * run ~75 kHz instead which should do no harm.
157		 */
158		dev_notice(&sch_adapter.dev,
159			"Clock divider uninitialized. Setting defaults\n");
160		outw(backbone_speed / (4 * 100), SMBHSTCLK);
161	}
162
163	dev_dbg(&sch_adapter.dev, "access size: %d %s\n", size,
164		(read_write)?"READ":"WRITE");
165	switch (size) {
166	case I2C_SMBUS_QUICK:
167		outb((addr << 1) | read_write, SMBHSTADD);
168		size = SCH_QUICK;
169		break;
170	case I2C_SMBUS_BYTE:
171		outb((addr << 1) | read_write, SMBHSTADD);
172		if (read_write == I2C_SMBUS_WRITE)
173			outb(command, SMBHSTCMD);
174		size = SCH_BYTE;
175		break;
176	case I2C_SMBUS_BYTE_DATA:
177		outb((addr << 1) | read_write, SMBHSTADD);
178		outb(command, SMBHSTCMD);
179		if (read_write == I2C_SMBUS_WRITE)
180			outb(data->byte, SMBHSTDAT0);
181		size = SCH_BYTE_DATA;
182		break;
183	case I2C_SMBUS_WORD_DATA:
184		outb((addr << 1) | read_write, SMBHSTADD);
185		outb(command, SMBHSTCMD);
186		if (read_write == I2C_SMBUS_WRITE) {
187			outb(data->word & 0xff, SMBHSTDAT0);
188			outb((data->word & 0xff00) >> 8, SMBHSTDAT1);
189		}
190		size = SCH_WORD_DATA;
191		break;
192	case I2C_SMBUS_BLOCK_DATA:
193		outb((addr << 1) | read_write, SMBHSTADD);
194		outb(command, SMBHSTCMD);
195		if (read_write == I2C_SMBUS_WRITE) {
196			len = data->block[0];
197			if (len == 0 || len > I2C_SMBUS_BLOCK_MAX)
198				return -EINVAL;
199			outb(len, SMBHSTDAT0);
200			for (i = 1; i <= len; i++)
201				outb(data->block[i], SMBBLKDAT+i-1);
202		}
203		size = SCH_BLOCK_DATA;
204		break;
205	default:
206		dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
207		return -EOPNOTSUPP;
208	}
209	dev_dbg(&sch_adapter.dev, "write size %d to 0x%04x\n", size, SMBHSTCNT);
210	outb((inb(SMBHSTCNT) & 0xb0) | (size & 0x7), SMBHSTCNT);
211
212	rc = sch_transaction();
213	if (rc)	/* Error in transaction */
214		return rc;
215
216	if ((read_write == I2C_SMBUS_WRITE) || (size == SCH_QUICK))
217		return 0;
218
219	switch (size) {
220	case SCH_BYTE:
221	case SCH_BYTE_DATA:
222		data->byte = inb(SMBHSTDAT0);
223		break;
224	case SCH_WORD_DATA:
225		data->word = inb(SMBHSTDAT0) + (inb(SMBHSTDAT1) << 8);
226		break;
227	case SCH_BLOCK_DATA:
228		data->block[0] = inb(SMBHSTDAT0);
229		if (data->block[0] == 0 || data->block[0] > I2C_SMBUS_BLOCK_MAX)
230			return -EPROTO;
231		for (i = 1; i <= data->block[0]; i++)
232			data->block[i] = inb(SMBBLKDAT+i-1);
233		break;
234	}
235	return 0;
236}
237
238static u32 sch_func(struct i2c_adapter *adapter)
239{
240	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
241	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
242	    I2C_FUNC_SMBUS_BLOCK_DATA;
243}
244
245static const struct i2c_algorithm smbus_algorithm = {
246	.smbus_xfer	= sch_access,
247	.functionality	= sch_func,
248};
249
250static struct i2c_adapter sch_adapter = {
251	.owner		= THIS_MODULE,
252	.class		= I2C_CLASS_HWMON | I2C_CLASS_SPD,
253	.algo		= &smbus_algorithm,
254};
255
256static int smbus_sch_probe(struct platform_device *dev)
257{
258	struct resource *res;
259	int retval;
260
261	res = platform_get_resource(dev, IORESOURCE_IO, 0);
262	if (!res)
263		return -EBUSY;
264
265	if (!devm_request_region(&dev->dev, res->start, resource_size(res),
266				 dev->name)) {
267		dev_err(&dev->dev, "SMBus region 0x%x already in use!\n",
268			sch_smba);
269		return -EBUSY;
270	}
271
272	sch_smba = res->start;
273
274	dev_dbg(&dev->dev, "SMBA = 0x%X\n", sch_smba);
275
276	/* set up the sysfs linkage to our parent device */
277	sch_adapter.dev.parent = &dev->dev;
278
279	snprintf(sch_adapter.name, sizeof(sch_adapter.name),
280		"SMBus SCH adapter at %04x", sch_smba);
281
282	retval = i2c_add_adapter(&sch_adapter);
283	if (retval)
 
284		sch_smba = 0;
 
285
286	return retval;
287}
288
289static int smbus_sch_remove(struct platform_device *pdev)
290{
291	if (sch_smba) {
292		i2c_del_adapter(&sch_adapter);
293		sch_smba = 0;
294	}
295
296	return 0;
297}
298
299static struct platform_driver smbus_sch_driver = {
300	.driver = {
301		.name = "isch_smbus",
 
302	},
303	.probe		= smbus_sch_probe,
304	.remove		= smbus_sch_remove,
305};
306
307module_platform_driver(smbus_sch_driver);
308
309MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@intel.com>");
310MODULE_DESCRIPTION("Intel SCH SMBus driver");
311MODULE_LICENSE("GPL");
312MODULE_ALIAS("platform:isch_smbus");
v3.15
 
  1/*
  2    i2c-isch.c - Linux kernel driver for Intel SCH chipset SMBus
  3    - Based on i2c-piix4.c
  4    Copyright (c) 1998 - 2002 Frodo Looijaard <frodol@dds.nl> and
  5    Philip Edelbrock <phil@netroedge.com>
  6    - Intel SCH support
  7    Copyright (c) 2007 - 2008 Jacob Jun Pan <jacob.jun.pan@intel.com>
  8
  9    This program is free software; you can redistribute it and/or modify
 10    it under the terms of the GNU General Public License version 2 as
 11    published by the Free Software Foundation.
 12
 13    This program is distributed in the hope that it will be useful,
 14    but WITHOUT ANY WARRANTY; without even the implied warranty of
 15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 16    GNU General Public License for more details.
 17
 18    You should have received a copy of the GNU General Public License
 19    along with this program; if not, write to the Free Software
 20    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 21*/
 22
 23/*
 24   Supports:
 25	Intel SCH chipsets (AF82US15W, AF82US15L, AF82UL11L)
 26   Note: we assume there can only be one device, with one SMBus interface.
 27*/
 28
 29#include <linux/module.h>
 30#include <linux/platform_device.h>
 31#include <linux/kernel.h>
 32#include <linux/delay.h>
 33#include <linux/stddef.h>
 34#include <linux/ioport.h>
 35#include <linux/i2c.h>
 36#include <linux/io.h>
 37#include <linux/acpi.h>
 38
 39/* SCH SMBus address offsets */
 40#define SMBHSTCNT	(0 + sch_smba)
 41#define SMBHSTSTS	(1 + sch_smba)
 42#define SMBHSTCLK	(2 + sch_smba)
 43#define SMBHSTADD	(4 + sch_smba) /* TSA */
 44#define SMBHSTCMD	(5 + sch_smba)
 45#define SMBHSTDAT0	(6 + sch_smba)
 46#define SMBHSTDAT1	(7 + sch_smba)
 47#define SMBBLKDAT	(0x20 + sch_smba)
 48
 49/* Other settings */
 50#define MAX_RETRIES	5000
 51
 52/* I2C constants */
 53#define SCH_QUICK		0x00
 54#define SCH_BYTE		0x01
 55#define SCH_BYTE_DATA		0x02
 56#define SCH_WORD_DATA		0x03
 57#define SCH_BLOCK_DATA		0x05
 58
 59static unsigned short sch_smba;
 60static struct i2c_adapter sch_adapter;
 61static int backbone_speed = 33000; /* backbone speed in kHz */
 62module_param(backbone_speed, int, S_IRUSR | S_IWUSR);
 63MODULE_PARM_DESC(backbone_speed, "Backbone speed in kHz, (default = 33000)");
 64
 65/*
 66 * Start the i2c transaction -- the i2c_access will prepare the transaction
 67 * and this function will execute it.
 68 * return 0 for success and others for failure.
 69 */
 70static int sch_transaction(void)
 71{
 72	int temp;
 73	int result = 0;
 74	int retries = 0;
 75
 76	dev_dbg(&sch_adapter.dev, "Transaction (pre): CNT=%02x, CMD=%02x, "
 77		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb(SMBHSTCNT),
 78		inb(SMBHSTCMD), inb(SMBHSTADD), inb(SMBHSTDAT0),
 79		inb(SMBHSTDAT1));
 80
 81	/* Make sure the SMBus host is ready to start transmitting */
 82	temp = inb(SMBHSTSTS) & 0x0f;
 83	if (temp) {
 84		/* Can not be busy since we checked it in sch_access */
 85		if (temp & 0x01) {
 86			dev_dbg(&sch_adapter.dev, "Completion (%02x). "
 87				"Clear...\n", temp);
 88		}
 89		if (temp & 0x06) {
 90			dev_dbg(&sch_adapter.dev, "SMBus error (%02x). "
 91				"Resetting...\n", temp);
 92		}
 93		outb(temp, SMBHSTSTS);
 94		temp = inb(SMBHSTSTS) & 0x0f;
 95		if (temp) {
 96			dev_err(&sch_adapter.dev,
 97				"SMBus is not ready: (%02x)\n", temp);
 98			return -EAGAIN;
 99		}
100	}
101
102	/* start the transaction by setting bit 4 */
103	outb(inb(SMBHSTCNT) | 0x10, SMBHSTCNT);
104
105	do {
106		usleep_range(100, 200);
107		temp = inb(SMBHSTSTS) & 0x0f;
108	} while ((temp & 0x08) && (retries++ < MAX_RETRIES));
109
110	/* If the SMBus is still busy, we give up */
111	if (retries > MAX_RETRIES) {
112		dev_err(&sch_adapter.dev, "SMBus Timeout!\n");
113		result = -ETIMEDOUT;
114	}
115	if (temp & 0x04) {
116		result = -EIO;
117		dev_dbg(&sch_adapter.dev, "Bus collision! SMBus may be "
118			"locked until next hard reset. (sorry!)\n");
119		/* Clock stops and slave is stuck in mid-transmission */
120	} else if (temp & 0x02) {
121		result = -EIO;
122		dev_err(&sch_adapter.dev, "Error: no response!\n");
123	} else if (temp & 0x01) {
124		dev_dbg(&sch_adapter.dev, "Post complete!\n");
125		outb(temp, SMBHSTSTS);
126		temp = inb(SMBHSTSTS) & 0x07;
127		if (temp & 0x06) {
128			/* Completion clear failed */
129			dev_dbg(&sch_adapter.dev, "Failed reset at end of "
130				"transaction (%02x), Bus error!\n", temp);
131		}
132	} else {
133		result = -ENXIO;
134		dev_dbg(&sch_adapter.dev, "No such address.\n");
135	}
136	dev_dbg(&sch_adapter.dev, "Transaction (post): CNT=%02x, CMD=%02x, "
137		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb(SMBHSTCNT),
138		inb(SMBHSTCMD), inb(SMBHSTADD), inb(SMBHSTDAT0),
139		inb(SMBHSTDAT1));
140	return result;
141}
142
143/*
144 * This is the main access entry for i2c-sch access
145 * adap is i2c_adapter pointer, addr is the i2c device bus address, read_write
146 * (0 for read and 1 for write), size is i2c transaction type and data is the
147 * union of transaction for data to be transferred or data read from bus.
148 * return 0 for success and others for failure.
149 */
150static s32 sch_access(struct i2c_adapter *adap, u16 addr,
151		 unsigned short flags, char read_write,
152		 u8 command, int size, union i2c_smbus_data *data)
153{
154	int i, len, temp, rc;
155
156	/* Make sure the SMBus host is not busy */
157	temp = inb(SMBHSTSTS) & 0x0f;
158	if (temp & 0x08) {
159		dev_dbg(&sch_adapter.dev, "SMBus busy (%02x)\n", temp);
160		return -EAGAIN;
161	}
162	temp = inw(SMBHSTCLK);
163	if (!temp) {
164		/*
165		 * We can't determine if we have 33 or 25 MHz clock for
166		 * SMBus, so expect 33 MHz and calculate a bus clock of
167		 * 100 kHz. If we actually run at 25 MHz the bus will be
168		 * run ~75 kHz instead which should do no harm.
169		 */
170		dev_notice(&sch_adapter.dev,
171			"Clock divider unitialized. Setting defaults\n");
172		outw(backbone_speed / (4 * 100), SMBHSTCLK);
173	}
174
175	dev_dbg(&sch_adapter.dev, "access size: %d %s\n", size,
176		(read_write)?"READ":"WRITE");
177	switch (size) {
178	case I2C_SMBUS_QUICK:
179		outb((addr << 1) | read_write, SMBHSTADD);
180		size = SCH_QUICK;
181		break;
182	case I2C_SMBUS_BYTE:
183		outb((addr << 1) | read_write, SMBHSTADD);
184		if (read_write == I2C_SMBUS_WRITE)
185			outb(command, SMBHSTCMD);
186		size = SCH_BYTE;
187		break;
188	case I2C_SMBUS_BYTE_DATA:
189		outb((addr << 1) | read_write, SMBHSTADD);
190		outb(command, SMBHSTCMD);
191		if (read_write == I2C_SMBUS_WRITE)
192			outb(data->byte, SMBHSTDAT0);
193		size = SCH_BYTE_DATA;
194		break;
195	case I2C_SMBUS_WORD_DATA:
196		outb((addr << 1) | read_write, SMBHSTADD);
197		outb(command, SMBHSTCMD);
198		if (read_write == I2C_SMBUS_WRITE) {
199			outb(data->word & 0xff, SMBHSTDAT0);
200			outb((data->word & 0xff00) >> 8, SMBHSTDAT1);
201		}
202		size = SCH_WORD_DATA;
203		break;
204	case I2C_SMBUS_BLOCK_DATA:
205		outb((addr << 1) | read_write, SMBHSTADD);
206		outb(command, SMBHSTCMD);
207		if (read_write == I2C_SMBUS_WRITE) {
208			len = data->block[0];
209			if (len == 0 || len > I2C_SMBUS_BLOCK_MAX)
210				return -EINVAL;
211			outb(len, SMBHSTDAT0);
212			for (i = 1; i <= len; i++)
213				outb(data->block[i], SMBBLKDAT+i-1);
214		}
215		size = SCH_BLOCK_DATA;
216		break;
217	default:
218		dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
219		return -EOPNOTSUPP;
220	}
221	dev_dbg(&sch_adapter.dev, "write size %d to 0x%04x\n", size, SMBHSTCNT);
222	outb((inb(SMBHSTCNT) & 0xb0) | (size & 0x7), SMBHSTCNT);
223
224	rc = sch_transaction();
225	if (rc)	/* Error in transaction */
226		return rc;
227
228	if ((read_write == I2C_SMBUS_WRITE) || (size == SCH_QUICK))
229		return 0;
230
231	switch (size) {
232	case SCH_BYTE:
233	case SCH_BYTE_DATA:
234		data->byte = inb(SMBHSTDAT0);
235		break;
236	case SCH_WORD_DATA:
237		data->word = inb(SMBHSTDAT0) + (inb(SMBHSTDAT1) << 8);
238		break;
239	case SCH_BLOCK_DATA:
240		data->block[0] = inb(SMBHSTDAT0);
241		if (data->block[0] == 0 || data->block[0] > I2C_SMBUS_BLOCK_MAX)
242			return -EPROTO;
243		for (i = 1; i <= data->block[0]; i++)
244			data->block[i] = inb(SMBBLKDAT+i-1);
245		break;
246	}
247	return 0;
248}
249
250static u32 sch_func(struct i2c_adapter *adapter)
251{
252	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
253	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
254	    I2C_FUNC_SMBUS_BLOCK_DATA;
255}
256
257static const struct i2c_algorithm smbus_algorithm = {
258	.smbus_xfer	= sch_access,
259	.functionality	= sch_func,
260};
261
262static struct i2c_adapter sch_adapter = {
263	.owner		= THIS_MODULE,
264	.class		= I2C_CLASS_HWMON | I2C_CLASS_SPD,
265	.algo		= &smbus_algorithm,
266};
267
268static int smbus_sch_probe(struct platform_device *dev)
269{
270	struct resource *res;
271	int retval;
272
273	res = platform_get_resource(dev, IORESOURCE_IO, 0);
274	if (!res)
275		return -EBUSY;
276
277	if (!devm_request_region(&dev->dev, res->start, resource_size(res),
278				 dev->name)) {
279		dev_err(&dev->dev, "SMBus region 0x%x already in use!\n",
280			sch_smba);
281		return -EBUSY;
282	}
283
284	sch_smba = res->start;
285
286	dev_dbg(&dev->dev, "SMBA = 0x%X\n", sch_smba);
287
288	/* set up the sysfs linkage to our parent device */
289	sch_adapter.dev.parent = &dev->dev;
290
291	snprintf(sch_adapter.name, sizeof(sch_adapter.name),
292		"SMBus SCH adapter at %04x", sch_smba);
293
294	retval = i2c_add_adapter(&sch_adapter);
295	if (retval) {
296		dev_err(&dev->dev, "Couldn't register adapter!\n");
297		sch_smba = 0;
298	}
299
300	return retval;
301}
302
303static int smbus_sch_remove(struct platform_device *pdev)
304{
305	if (sch_smba) {
306		i2c_del_adapter(&sch_adapter);
307		sch_smba = 0;
308	}
309
310	return 0;
311}
312
313static struct platform_driver smbus_sch_driver = {
314	.driver = {
315		.name = "isch_smbus",
316		.owner = THIS_MODULE,
317	},
318	.probe		= smbus_sch_probe,
319	.remove		= smbus_sch_remove,
320};
321
322module_platform_driver(smbus_sch_driver);
323
324MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@intel.com>");
325MODULE_DESCRIPTION("Intel SCH SMBus driver");
326MODULE_LICENSE("GPL");
327MODULE_ALIAS("platform:isch_smbus");