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/drivers/i2c/busses/i2c-ali1535.c

http://github.com/mirrors/linux
C | 527 lines | 342 code | 66 blank | 119 comment | 50 complexity | 17472eaaf2a5928c16143669e180a99c MD5 | raw file
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Copyright (c) 2000  Frodo Looijaard <frodol@dds.nl>,
  4 *                      Philip Edelbrock <phil@netroedge.com>,
  5 *                      Mark D. Studebaker <mdsxyz123@yahoo.com>,
  6 *                      Dan Eaton <dan.eaton@rocketlogix.com> and
  7 *                      Stephen Rousset <stephen.rousset@rocketlogix.com>
  8*/
  9
 10/*
 11    This is the driver for the SMB Host controller on
 12    Acer Labs Inc. (ALI) M1535 South Bridge.
 13
 14    The M1535 is a South bridge for portable systems.
 15    It is very similar to the M15x3 South bridges also produced
 16    by Acer Labs Inc.  Some of the registers within the part
 17    have moved and some have been redefined slightly. Additionally,
 18    the sequencing of the SMBus transactions has been modified
 19    to be more consistent with the sequencing recommended by
 20    the manufacturer and observed through testing.  These
 21    changes are reflected in this driver and can be identified
 22    by comparing this driver to the i2c-ali15x3 driver.
 23    For an overview of these chips see http://www.acerlabs.com
 24
 25    The SMB controller is part of the 7101 device, which is an
 26    ACPI-compliant Power Management Unit (PMU).
 27
 28    The whole 7101 device has to be enabled for the SMB to work.
 29    You can't just enable the SMB alone.
 30    The SMB and the ACPI have separate I/O spaces.
 31    We make sure that the SMB is enabled. We leave the ACPI alone.
 32
 33    This driver controls the SMB Host only.
 34
 35    This driver does not use interrupts.
 36*/
 37
 38
 39/* Note: we assume there can only be one ALI1535, with one SMBus interface */
 40
 41#include <linux/module.h>
 42#include <linux/pci.h>
 43#include <linux/kernel.h>
 44#include <linux/stddef.h>
 45#include <linux/delay.h>
 46#include <linux/ioport.h>
 47#include <linux/i2c.h>
 48#include <linux/acpi.h>
 49#include <linux/io.h>
 50
 51
 52/* ALI1535 SMBus address offsets */
 53#define SMBHSTSTS	(0 + ali1535_smba)
 54#define SMBHSTTYP	(1 + ali1535_smba)
 55#define SMBHSTPORT	(2 + ali1535_smba)
 56#define SMBHSTCMD	(7 + ali1535_smba)
 57#define SMBHSTADD	(3 + ali1535_smba)
 58#define SMBHSTDAT0	(4 + ali1535_smba)
 59#define SMBHSTDAT1	(5 + ali1535_smba)
 60#define SMBBLKDAT	(6 + ali1535_smba)
 61
 62/* PCI Address Constants */
 63#define SMBCOM		0x004
 64#define SMBREV		0x008
 65#define SMBCFG		0x0D1
 66#define SMBBA		0x0E2
 67#define SMBHSTCFG	0x0F0
 68#define SMBCLK		0x0F2
 69
 70/* Other settings */
 71#define MAX_TIMEOUT		500	/* times 1/100 sec */
 72#define ALI1535_SMB_IOSIZE	32
 73
 74#define ALI1535_SMB_DEFAULTBASE	0x8040
 75
 76/* ALI1535 address lock bits */
 77#define ALI1535_LOCK		0x06	/* dwe */
 78
 79/* ALI1535 command constants */
 80#define ALI1535_QUICK		0x00
 81#define ALI1535_BYTE		0x10
 82#define ALI1535_BYTE_DATA	0x20
 83#define ALI1535_WORD_DATA	0x30
 84#define ALI1535_BLOCK_DATA	0x40
 85#define ALI1535_I2C_READ	0x60
 86
 87#define	ALI1535_DEV10B_EN	0x80	/* Enable 10-bit addressing in	*/
 88					/*  I2C read			*/
 89#define	ALI1535_T_OUT		0x08	/* Time-out Command (write)	*/
 90#define	ALI1535_A_HIGH_BIT9	0x08	/* Bit 9 of 10-bit address in	*/
 91					/* Alert-Response-Address	*/
 92					/* (read)			*/
 93#define	ALI1535_KILL		0x04	/* Kill Command (write)		*/
 94#define	ALI1535_A_HIGH_BIT8	0x04	/* Bit 8 of 10-bit address in	*/
 95					/*  Alert-Response-Address	*/
 96					/*  (read)			*/
 97
 98#define	ALI1535_D_HI_MASK	0x03	/* Mask for isolating bits 9-8	*/
 99					/*  of 10-bit address in I2C	*/
100					/*  Read Command		*/
101
102/* ALI1535 status register bits */
103#define ALI1535_STS_IDLE	0x04
104#define ALI1535_STS_BUSY	0x08	/* host busy */
105#define ALI1535_STS_DONE	0x10	/* transaction complete */
106#define ALI1535_STS_DEV		0x20	/* device error */
107#define ALI1535_STS_BUSERR	0x40	/* bus error    */
108#define ALI1535_STS_FAIL	0x80	/* failed bus transaction */
109#define ALI1535_STS_ERR		0xE0	/* all the bad error bits */
110
111#define ALI1535_BLOCK_CLR	0x04	/* reset block data index */
112
113/* ALI1535 device address register bits */
114#define	ALI1535_RD_ADDR		0x01	/* Read/Write Bit in Device	*/
115					/*  Address field		*/
116					/*  -> Write = 0		*/
117					/*  -> Read  = 1		*/
118#define	ALI1535_SMBIO_EN	0x04	/* SMB I/O Space enable		*/
119
120static struct pci_driver ali1535_driver;
121static unsigned long ali1535_smba;
122static unsigned short ali1535_offset;
123
124/* Detect whether a ALI1535 can be found, and initialize it, where necessary.
125   Note the differences between kernels with the old PCI BIOS interface and
126   newer kernels with the real PCI interface. In compat.h some things are
127   defined to make the transition easier. */
128static int ali1535_setup(struct pci_dev *dev)
129{
130	int retval;
131	unsigned char temp;
132
133	/* Check the following things:
134		- SMB I/O address is initialized
135		- Device is enabled
136		- We can use the addresses
137	*/
138
139	retval = pci_enable_device(dev);
140	if (retval) {
141		dev_err(&dev->dev, "ALI1535_smb can't enable device\n");
142		goto exit;
143	}
144
145	/* Determine the address of the SMBus area */
146	pci_read_config_word(dev, SMBBA, &ali1535_offset);
147	dev_dbg(&dev->dev, "ALI1535_smb is at offset 0x%04x\n", ali1535_offset);
148	ali1535_offset &= (0xffff & ~(ALI1535_SMB_IOSIZE - 1));
149	if (ali1535_offset == 0) {
150		dev_warn(&dev->dev,
151			"ALI1535_smb region uninitialized - upgrade BIOS?\n");
152		retval = -ENODEV;
153		goto exit;
154	}
155
156	if (pci_resource_flags(dev, 0) & IORESOURCE_IO)
157		ali1535_smba = pci_resource_start(dev, 0) + ali1535_offset;
158	else
159		ali1535_smba = ali1535_offset;
160
161	retval = acpi_check_region(ali1535_smba, ALI1535_SMB_IOSIZE,
162				   ali1535_driver.name);
163	if (retval)
164		goto exit;
165
166	if (!request_region(ali1535_smba, ALI1535_SMB_IOSIZE,
167			    ali1535_driver.name)) {
168		dev_err(&dev->dev, "ALI1535_smb region 0x%lx already in use!\n",
169			ali1535_smba);
170		retval = -EBUSY;
171		goto exit;
172	}
173
174	/* check if whole device is enabled */
175	pci_read_config_byte(dev, SMBCFG, &temp);
176	if ((temp & ALI1535_SMBIO_EN) == 0) {
177		dev_err(&dev->dev, "SMB device not enabled - upgrade BIOS?\n");
178		retval = -ENODEV;
179		goto exit_free;
180	}
181
182	/* Is SMB Host controller enabled? */
183	pci_read_config_byte(dev, SMBHSTCFG, &temp);
184	if ((temp & 1) == 0) {
185		dev_err(&dev->dev, "SMBus controller not enabled - upgrade BIOS?\n");
186		retval = -ENODEV;
187		goto exit_free;
188	}
189
190	/* set SMB clock to 74KHz as recommended in data sheet */
191	pci_write_config_byte(dev, SMBCLK, 0x20);
192
193	/*
194	  The interrupt routing for SMB is set up in register 0x77 in the
195	  1533 ISA Bridge device, NOT in the 7101 device.
196	  Don't bother with finding the 1533 device and reading the register.
197	if ((....... & 0x0F) == 1)
198		dev_dbg(&dev->dev, "ALI1535 using Interrupt 9 for SMBus.\n");
199	*/
200	pci_read_config_byte(dev, SMBREV, &temp);
201	dev_dbg(&dev->dev, "SMBREV = 0x%X\n", temp);
202	dev_dbg(&dev->dev, "ALI1535_smba = 0x%lx\n", ali1535_smba);
203
204	return 0;
205
206exit_free:
207	release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
208exit:
209	return retval;
210}
211
212static int ali1535_transaction(struct i2c_adapter *adap)
213{
214	int temp;
215	int result = 0;
216	int timeout = 0;
217
218	dev_dbg(&adap->dev, "Transaction (pre): STS=%02x, TYP=%02x, "
219		"CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
220		inb_p(SMBHSTSTS), inb_p(SMBHSTTYP), inb_p(SMBHSTCMD),
221		inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
222
223	/* get status */
224	temp = inb_p(SMBHSTSTS);
225
226	/* Make sure the SMBus host is ready to start transmitting */
227	/* Check the busy bit first */
228	if (temp & ALI1535_STS_BUSY) {
229		/* If the host controller is still busy, it may have timed out
230		 * in the previous transaction, resulting in a "SMBus Timeout"
231		 * printk.  I've tried the following to reset a stuck busy bit.
232		 *   1. Reset the controller with an KILL command. (this
233		 *      doesn't seem to clear the controller if an external
234		 *      device is hung)
235		 *   2. Reset the controller and the other SMBus devices with a
236		 *      T_OUT command. (this clears the host busy bit if an
237		 *      external device is hung, but it comes back upon a new
238		 *      access to a device)
239		 *   3. Disable and reenable the controller in SMBHSTCFG. Worst
240		 *      case, nothing seems to work except power reset.
241		 */
242
243		/* Try resetting entire SMB bus, including other devices - This
244		 * may not work either - it clears the BUSY bit but then the
245		 * BUSY bit may come back on when you try and use the chip
246		 * again.  If that's the case you are stuck.
247		 */
248		dev_info(&adap->dev,
249			"Resetting entire SMB Bus to clear busy condition (%02x)\n",
250			temp);
251		outb_p(ALI1535_T_OUT, SMBHSTTYP);
252		temp = inb_p(SMBHSTSTS);
253	}
254
255	/* now check the error bits and the busy bit */
256	if (temp & (ALI1535_STS_ERR | ALI1535_STS_BUSY)) {
257		/* do a clear-on-write */
258		outb_p(0xFF, SMBHSTSTS);
259		temp = inb_p(SMBHSTSTS);
260		if (temp & (ALI1535_STS_ERR | ALI1535_STS_BUSY)) {
261			/* This is probably going to be correctable only by a
262			 * power reset as one of the bits now appears to be
263			 * stuck */
264			/* This may be a bus or device with electrical problems. */
265			dev_err(&adap->dev,
266				"SMBus reset failed! (0x%02x) - controller or "
267				"device on bus is probably hung\n", temp);
268			return -EBUSY;
269		}
270	} else {
271		/* check and clear done bit */
272		if (temp & ALI1535_STS_DONE)
273			outb_p(temp, SMBHSTSTS);
274	}
275
276	/* start the transaction by writing anything to the start register */
277	outb_p(0xFF, SMBHSTPORT);
278
279	/* We will always wait for a fraction of a second! */
280	timeout = 0;
281	do {
282		usleep_range(1000, 2000);
283		temp = inb_p(SMBHSTSTS);
284	} while (((temp & ALI1535_STS_BUSY) && !(temp & ALI1535_STS_IDLE))
285		 && (timeout++ < MAX_TIMEOUT));
286
287	/* If the SMBus is still busy, we give up */
288	if (timeout > MAX_TIMEOUT) {
289		result = -ETIMEDOUT;
290		dev_err(&adap->dev, "SMBus Timeout!\n");
291	}
292
293	if (temp & ALI1535_STS_FAIL) {
294		result = -EIO;
295		dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
296	}
297
298	/* Unfortunately the ALI SMB controller maps "no response" and "bus
299	 * collision" into a single bit. No response is the usual case so don't
300	 * do a printk.  This means that bus collisions go unreported.
301	 */
302	if (temp & ALI1535_STS_BUSERR) {
303		result = -ENXIO;
304		dev_dbg(&adap->dev,
305			"Error: no response or bus collision ADD=%02x\n",
306			inb_p(SMBHSTADD));
307	}
308
309	/* haven't ever seen this */
310	if (temp & ALI1535_STS_DEV) {
311		result = -EIO;
312		dev_err(&adap->dev, "Error: device error\n");
313	}
314
315	/* check to see if the "command complete" indication is set */
316	if (!(temp & ALI1535_STS_DONE)) {
317		result = -ETIMEDOUT;
318		dev_err(&adap->dev, "Error: command never completed\n");
319	}
320
321	dev_dbg(&adap->dev, "Transaction (post): STS=%02x, TYP=%02x, "
322		"CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
323		inb_p(SMBHSTSTS), inb_p(SMBHSTTYP), inb_p(SMBHSTCMD),
324		inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
325
326	/* take consequent actions for error conditions */
327	if (!(temp & ALI1535_STS_DONE)) {
328		/* issue "kill" to reset host controller */
329		outb_p(ALI1535_KILL, SMBHSTTYP);
330		outb_p(0xFF, SMBHSTSTS);
331	} else if (temp & ALI1535_STS_ERR) {
332		/* issue "timeout" to reset all devices on bus */
333		outb_p(ALI1535_T_OUT, SMBHSTTYP);
334		outb_p(0xFF, SMBHSTSTS);
335	}
336
337	return result;
338}
339
340/* Return negative errno on error. */
341static s32 ali1535_access(struct i2c_adapter *adap, u16 addr,
342			  unsigned short flags, char read_write, u8 command,
343			  int size, union i2c_smbus_data *data)
344{
345	int i, len;
346	int temp;
347	int timeout;
348	s32 result = 0;
349
350	/* make sure SMBus is idle */
351	temp = inb_p(SMBHSTSTS);
352	for (timeout = 0;
353	     (timeout < MAX_TIMEOUT) && !(temp & ALI1535_STS_IDLE);
354	     timeout++) {
355		usleep_range(1000, 2000);
356		temp = inb_p(SMBHSTSTS);
357	}
358	if (timeout >= MAX_TIMEOUT)
359		dev_warn(&adap->dev, "Idle wait Timeout! STS=0x%02x\n", temp);
360
361	/* clear status register (clear-on-write) */
362	outb_p(0xFF, SMBHSTSTS);
363
364	switch (size) {
365	case I2C_SMBUS_QUICK:
366		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
367		       SMBHSTADD);
368		size = ALI1535_QUICK;
369		outb_p(size, SMBHSTTYP);	/* output command */
370		break;
371	case I2C_SMBUS_BYTE:
372		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
373		       SMBHSTADD);
374		size = ALI1535_BYTE;
375		outb_p(size, SMBHSTTYP);	/* output command */
376		if (read_write == I2C_SMBUS_WRITE)
377			outb_p(command, SMBHSTCMD);
378		break;
379	case I2C_SMBUS_BYTE_DATA:
380		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
381		       SMBHSTADD);
382		size = ALI1535_BYTE_DATA;
383		outb_p(size, SMBHSTTYP);	/* output command */
384		outb_p(command, SMBHSTCMD);
385		if (read_write == I2C_SMBUS_WRITE)
386			outb_p(data->byte, SMBHSTDAT0);
387		break;
388	case I2C_SMBUS_WORD_DATA:
389		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
390		       SMBHSTADD);
391		size = ALI1535_WORD_DATA;
392		outb_p(size, SMBHSTTYP);	/* output command */
393		outb_p(command, SMBHSTCMD);
394		if (read_write == I2C_SMBUS_WRITE) {
395			outb_p(data->word & 0xff, SMBHSTDAT0);
396			outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
397		}
398		break;
399	case I2C_SMBUS_BLOCK_DATA:
400		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
401		       SMBHSTADD);
402		size = ALI1535_BLOCK_DATA;
403		outb_p(size, SMBHSTTYP);	/* output command */
404		outb_p(command, SMBHSTCMD);
405		if (read_write == I2C_SMBUS_WRITE) {
406			len = data->block[0];
407			if (len < 0) {
408				len = 0;
409				data->block[0] = len;
410			}
411			if (len > 32) {
412				len = 32;
413				data->block[0] = len;
414			}
415			outb_p(len, SMBHSTDAT0);
416			/* Reset SMBBLKDAT */
417			outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
418			for (i = 1; i <= len; i++)
419				outb_p(data->block[i], SMBBLKDAT);
420		}
421		break;
422	default:
423		dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
424		result = -EOPNOTSUPP;
425		goto EXIT;
426	}
427
428	result = ali1535_transaction(adap);
429	if (result)
430		goto EXIT;
431
432	if ((read_write == I2C_SMBUS_WRITE) || (size == ALI1535_QUICK)) {
433		result = 0;
434		goto EXIT;
435	}
436
437	switch (size) {
438	case ALI1535_BYTE:	/* Result put in SMBHSTDAT0 */
439		data->byte = inb_p(SMBHSTDAT0);
440		break;
441	case ALI1535_BYTE_DATA:
442		data->byte = inb_p(SMBHSTDAT0);
443		break;
444	case ALI1535_WORD_DATA:
445		data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
446		break;
447	case ALI1535_BLOCK_DATA:
448		len = inb_p(SMBHSTDAT0);
449		if (len > 32)
450			len = 32;
451		data->block[0] = len;
452		/* Reset SMBBLKDAT */
453		outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
454		for (i = 1; i <= data->block[0]; i++) {
455			data->block[i] = inb_p(SMBBLKDAT);
456			dev_dbg(&adap->dev, "Blk: len=%d, i=%d, data=%02x\n",
457				len, i, data->block[i]);
458		}
459		break;
460	}
461EXIT:
462	return result;
463}
464
465
466static u32 ali1535_func(struct i2c_adapter *adapter)
467{
468	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
469	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
470	    I2C_FUNC_SMBUS_BLOCK_DATA;
471}
472
473static const struct i2c_algorithm smbus_algorithm = {
474	.smbus_xfer	= ali1535_access,
475	.functionality	= ali1535_func,
476};
477
478static struct i2c_adapter ali1535_adapter = {
479	.owner		= THIS_MODULE,
480	.class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
481	.algo		= &smbus_algorithm,
482};
483
484static const struct pci_device_id ali1535_ids[] = {
485	{ PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
486	{ },
487};
488
489MODULE_DEVICE_TABLE(pci, ali1535_ids);
490
491static int ali1535_probe(struct pci_dev *dev, const struct pci_device_id *id)
492{
493	if (ali1535_setup(dev)) {
494		dev_warn(&dev->dev,
495			"ALI1535 not detected, module not inserted.\n");
496		return -ENODEV;
497	}
498
499	/* set up the sysfs linkage to our parent device */
500	ali1535_adapter.dev.parent = &dev->dev;
501
502	snprintf(ali1535_adapter.name, sizeof(ali1535_adapter.name),
503		"SMBus ALI1535 adapter at %04x", ali1535_offset);
504	return i2c_add_adapter(&ali1535_adapter);
505}
506
507static void ali1535_remove(struct pci_dev *dev)
508{
509	i2c_del_adapter(&ali1535_adapter);
510	release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
511}
512
513static struct pci_driver ali1535_driver = {
514	.name		= "ali1535_smbus",
515	.id_table	= ali1535_ids,
516	.probe		= ali1535_probe,
517	.remove		= ali1535_remove,
518};
519
520module_pci_driver(ali1535_driver);
521
522MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>, "
523	      "Philip Edelbrock <phil@netroedge.com>, "
524	      "Mark D. Studebaker <mdsxyz123@yahoo.com> "
525	      "and Dan Eaton <dan.eaton@rocketlogix.com>");
526MODULE_DESCRIPTION("ALI1535 SMBus driver");
527MODULE_LICENSE("GPL");