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i2c-sis630.c @ 1504

Revision 1504, 11.3 KB (checked in by amalysh, 11 years ago)
(amalysh) Fixed the typo in sis630_access Changed sis630_transaction. Now it's 2x faster...
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1	/*
2	SIS 630 SMBUS access implementation based on i2c-sis5595.
3
4	Copyright (c) 2002 Alexander Malysh <amalysh@web.de>
5
6	This program is free software; you can redistribute it and/or modify
7	it under the terms of the GNU General Public License as published by
8	the Free Software Foundation; either version 2 of the License, or
9	(at your option) any later version.
10
11	This program is distributed in the hope that it will be useful,
12	but WITHOUT ANY WARRANTY; without even the implied warranty of
13	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14	GNU General Public License for more details.
15
16	You should have received a copy of the GNU General Public License
17	along with this program; if not, write to the Free Software
18	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19	*/
20
21	/*
22	Changes:
23	24.08.2002
24	Fixed the typo in sis630_access (Thanks to Mark M. Hoffman)
25	Changed sis630_transaction. Now it's 2x faster (Thanks to Mark M. Hoffman)
26	*/
27
28	/*
29	TODO:
30	Implement block data write/read
31	Check SMBALT# : why it can't be cleared ????
32	Test on 2.2 kernel
33	*/
34	/*
35	Supports:
36	SIS 630
37
38	Note: we assume there can only be one device, with one SMBus interface.
39	*/
40
41	#include <linux/version.h>
42	#include <linux/module.h>
43	#include <asm/io.h>
44	#include <linux/kernel.h>
45	#include <linux/pci.h>
46	#include <linux/stddef.h>
47	#include <linux/sched.h>
48	#include <linux/ioport.h>
49	#include <linux/i2c.h>
50	#include "version.h"
51	#include <linux/init.h>
52
53	#ifndef I2C_HW_SMBUS_SIS630
54	#define I2C_HW_SMBUS_SIS630 0x08
55	#endif
56
57	/* SIS630 SMBus registers */
58	#define SMB_STS 0x80 /* status */
59	#define SMB_EN 0x81 /* status enable */
60	#define SMB_CNT 0x82
61	#define SMBHOST_CNT 0x83
62	#define SMB_ADDR 0x84
63	#define SMB_CMD 0x85
64	#define SMB_PCOUNT 0x86 /* processed count */
65	#define SMB_COUNT 0x87
66	#define SMB_BYTE 0x88 /* ~0x8F data byte field */
67	#define SMBDEV_ADDR 0x90
68	#define SMB_DB0 0x91
69	#define SMB_DB1 0x92
70	#define SMB_SAA 0x93
71
72	/* register count for request_region */
73	#define SIS630_SMB_IOREGION 20
74
75	/* PCI address constants */
76	/* acpi base address register */
77	#define SIS630_ACPI_BASE_REG 0x74
78	/* bios control register */
79	#define SIS630_BIOS_CTL_REG 0x40
80
81	/* Other settings */
82	#define MAX_TIMEOUT 500
83
84	/* SIS630 constants */
85	#define SIS630_QUICK 0x00
86	#define SIS630_BYTE 0x01
87	#define SIS630_BYTE_DATA 0x02
88	#define SIS630_WORD_DATA 0x03
89	#define SIS630_PCALL 0x04
90	#define SIS630_BLOCK_DATA 0x05
91
92
93	#ifdef MODULE
94	static
95	#else
96	extern
97	#endif
98	int __init i2c_sis630_init(void);
99	static int __init i2c_sis630_cleanup(void);
100	static int sis630_setup(void);
101	static s32 sis630_access(struct i2c_adapter *adap, u16 addr,
102	unsigned short flags, char read_write,
103	u8 command, int size,
104	union i2c_smbus_data *data);
105	static void sis630_do_pause(unsigned int amount);
106	static int sis630_transaction(int size);
107	static void sis630_inc(struct i2c_adapter *adapter);
108	static void sis630_dec(struct i2c_adapter *adapter);
109	static u32 sis630_func(struct i2c_adapter *adapter);
110	static u8 sis630_read(u8 reg);
111	static void sis630_write(u8 reg, u8 data);
112
113
114	static struct i2c_algorithm smbus_algorithm = {
115	/* name */ "Non-I2C SMBus adapter",
116	/* id */ I2C_ALGO_SMBUS,
117	/* master_xfer */ NULL,
118	/* smbus_access */ sis630_access,
119	/* slave_send */ NULL,
120	/* slave_rcv */ NULL,
121	/* algo_control */ NULL,
122	/* functionality */ sis630_func,
123	};
124
125	static struct i2c_adapter sis630_adapter = {
126	"unset",
127	I2C_ALGO_SMBUS \| I2C_HW_SMBUS_SIS630,
128	&smbus_algorithm,
129	NULL,
130	sis630_inc,
131	sis630_dec,
132	NULL,
133	NULL,
134	};
135
136	static unsigned short acpi_base = 0;
137	static int __initdata sis630_initialized;
138
139	u8 sis630_read(u8 reg) {
140	return inb(acpi_base + reg);
141	}
142
143	void sis630_write(u8 reg, u8 data) {
144	outb(data, acpi_base + reg);
145	}
146
147	/* Internally used pause function */
148	void sis630_do_pause(unsigned int amount)
149	{
150	current->state = TASK_INTERRUPTIBLE;
151	schedule_timeout(amount);
152	}
153
154	int sis630_transaction(int size) {
155	int temp;
156	int result = 0;
157	int timeout = 0;
158
159	/*
160	Make sure the SMBus host is ready to start transmitting.
161	*/
162	if ((temp = sis630_read(SMB_CNT) & 0x03) != 0x00) {
163	#ifdef DEBUG
164	printk(KERN_DEBUG "i2c-sis630.o: SMBus busy (%02x). "
165	"Resetting...\n",temp);
166	#endif
167	/* kill smbus transaction */
168	sis630_write(SMBHOST_CNT, 0x02);
169
170	if ((temp = sis630_read(SMB_CNT) & 0x03) != 0x00) {
171	#ifdef DEBUG
172	printk(KERN_DEBUG "i2c-sis630.o: Failed! (%02x)\n",
173	temp);
174	#endif
175	return -1;
176	} else {
177	#ifdef DEBUG
178	printk(KERN_DEBUG "i2c-sis630.o: Successfull!\n");
179	#endif
180	}
181	}
182
183	/* disable timeout interrupt and set clock to 56KHz */
184	sis630_write(SMB_CNT, 0x20);
185
186	/* clear all sticky bits */
187	temp = sis630_read(SMB_STS);
188	sis630_write(SMB_STS, temp & 0x1e);
189
190	/* start the transaction by setting bit 4 and size */
191	sis630_write(SMBHOST_CNT,0x10 \| (size & 0x07));
192
193	/* We will always wait for a fraction of a second! */
194	do {
195	sis630_do_pause(1);
196	temp = sis630_read(SMB_STS);
197	} while (!(temp & 0x0e) && (timeout++ < MAX_TIMEOUT));
198
199	/* If the SMBus is still busy, we give up */
200	if (timeout >= MAX_TIMEOUT) {
201	#ifdef DEBUG
202	printk(KERN_DEBUG "i2c-sis630.o: SMBus Timeout!\n");
203	#endif
204	result = -1;
205	}
206
207	if (temp & 0x02) {
208	result = -1;
209	#ifdef DEBUG
210	printk(KERN_DEBUG "i2c-sis630.o: Error: Failed bus "
211	"transaction\n");
212	#endif
213	}
214
215	if (temp & 0x04) {
216	result = -1;
217	printk(KERN_ERR "i2c-sis630.o: Bus collision! "
218	"SMBus may be locked until next hard reset (or not...)\n");
219	/* TBD: Datasheet say:
220	the software should clear this bit and restart SMBUS operation
221	*/
222	}
223
224	/* clear all status "sticky" bits */
225	sis630_write(SMB_STS, temp);
226
227	return result;
228	}
229
230	/* Return -1 on error. */
231	s32 sis630_access(struct i2c_adapter * adap, u16 addr,
232	unsigned short flags, char read_write,
233	u8 command, int size, union i2c_smbus_data * data) {
234
235	switch (size) {
236	case I2C_SMBUS_QUICK:
237	sis630_write(SMB_ADDR, ((addr & 0x7f) << 1) \| (read_write & 0x01));
238	size = SIS630_QUICK;
239	break;
240	case I2C_SMBUS_BYTE:
241	sis630_write(SMB_ADDR, ((addr & 0x7f) << 1) \| (read_write & 0x01));
242	if (read_write == I2C_SMBUS_WRITE)
243	sis630_write(SMB_CMD, command);
244	size = SIS630_BYTE;
245	break;
246	case I2C_SMBUS_BYTE_DATA:
247	sis630_write(SMB_ADDR, ((addr & 0x7f) << 1) \| (read_write & 0x01));
248	sis630_write(SMB_CMD, command);
249	if (read_write == I2C_SMBUS_WRITE)
250	sis630_write(SMB_BYTE, data->byte);
251	size = SIS630_BYTE_DATA;
252	break;
253	case I2C_SMBUS_PROC_CALL:
254	case I2C_SMBUS_WORD_DATA:
255	sis630_write(SMB_ADDR,((addr & 0x7f) << 1) \| (read_write & 0x01));
256	sis630_write(SMB_CMD, command);
257	if (read_write == I2C_SMBUS_WRITE) {
258	sis630_write(SMB_BYTE, data->word & 0xff);
259	sis630_write(SMB_BYTE + 1,(data->word & 0xff00) >> 8);
260	}
261	size = (size == I2C_SMBUS_PROC_CALL ? SIS630_PCALL : SIS630_WORD_DATA);
262	break;
263	case I2C_SMBUS_BLOCK_DATA:
264	/* it's not implemented yet, but comming soon */
265	#if 0
266	sis630_write(SMB_ADDR,((addr & 0x7f) << 1) \| (read_write & 0x01));
267	sis630_write(SMB_CMD, command);
268	size = SIS630_BLOCK_DATA;
269	#endif
270	default:
271	printk("Unsupported I2C size\n");
272	return -1;
273	break;
274	}
275
276
277	if (sis630_transaction(size))
278	return -1;
279
280	if ((size != I2C_SMBUS_PROC_CALL) &&
281	((read_write == I2C_SMBUS_WRITE) \|\| (size == I2C_SMBUS_QUICK))) {
282	return 0;
283	}
284
285	switch(size) {
286	case SIS630_BYTE:
287	case SIS630_BYTE_DATA:
288	data->byte = sis630_read(SMB_BYTE);
289	break;
290	case SIS630_PCALL:
291	case SIS630_WORD_DATA:
292	data->word = sis630_read(SMB_BYTE) + (sis630_read(SMB_BYTE + 1) << 8);
293	break;
294	default:
295	return -1;
296	break;
297	}
298
299	return 0;
300	}
301
302	void sis630_inc(struct i2c_adapter *adapter) {
303	MOD_INC_USE_COUNT;
304	}
305
306	void sis630_dec(struct i2c_adapter *adapter) {
307	MOD_DEC_USE_COUNT;
308	}
309
310	u32 sis630_func(struct i2c_adapter *adapter) {
311	return I2C_FUNC_SMBUS_QUICK \| I2C_FUNC_SMBUS_BYTE \| I2C_FUNC_SMBUS_BYTE_DATA \|
312	I2C_FUNC_SMBUS_WORD_DATA \| I2C_FUNC_SMBUS_PROC_CALL;
313	}
314
315	int sis630_setup(void) {
316	unsigned char b;
317	struct pci_dev *sis630_dev = NULL;
318
319	/* First check whether we can access PCI at all */
320	if (pci_present() == 0) {
321	printk("i2c-sis630.o: Error: No PCI-bus found!\n");
322	return -ENODEV;
323	}
324
325	/* Look for the SIS630 */
326	if (!(sis630_dev = pci_find_device(PCI_VENDOR_ID_SI,
327	PCI_DEVICE_ID_SI_503,
328	sis630_dev))) {
329	printk(KERN_ERR "i2c-sis630.o: Error: Can't detect SIS630!\n");
330	return -ENODEV;
331	}
332	if (NULL == pci_find_device(PCI_VENDOR_ID_SI,PCI_DEVICE_ID_SI_630,NULL)) {
333	printk(KERN_ERR "i2c-sis630.o: Error: Can't detect SIS630!\n");
334	return -ENODEV;
335	}
336
337	/*
338	Enable ACPI first , so we can accsess reg 74-75
339	in acpi io space and read acpi base addr
340	*/
341	if (PCIBIOS_SUCCESSFUL !=
342	pci_read_config_byte(sis630_dev, SIS630_BIOS_CTL_REG,&b)) {
343	printk(KERN_ERR "i2c-sis630.o: Error: Can't read bios ctl reg\n");
344	return -ENODEV;
345	}
346	/* if ACPI already anbled , do nothing */
347	if (!(b & 0x80) &&
348	PCIBIOS_SUCCESSFUL !=
349	pci_write_config_byte(sis630_dev,SIS630_BIOS_CTL_REG,b\|0x80)) {
350	printk(KERN_ERR "i2c-sis630.o: Error: Can't enable ACPI\n");
351	return -ENODEV;
352	}
353	/* Determine the ACPI base address */
354	if (PCIBIOS_SUCCESSFUL !=
355	pci_read_config_word(sis630_dev,SIS630_ACPI_BASE_REG,&acpi_base)) {
356	printk(KERN_ERR "i2c-sis630.o: Error: Can't determine ACPI base address\n");
357	return -ENODEV;
358	}
359
360	#ifdef DEBUG
361	printk(KERN_DEBUG "i2c-sis630.o: ACPI base at 0x%04x\n", acpi_base);
362	#endif
363
364	/* Everything is happy, let's grab the memory and set things up. */
365	if (!request_region(acpi_base + SMB_STS, SIS630_SMB_IOREGION, "sis630-smbus")){
366	printk(KERN_ERR "i2c-sis630.o: SMBus registers 0x%04x-0x%04x "
367	"already in use!\n",acpi_base + SMB_STS, acpi_base + SMB_SAA);
368	return -ENODEV;
369	}
370
371	return 0;
372	}
373
374	int __init i2c_sis630_init(void) {
375	int res;
376	printk("i2c-sis630.o version %s (%s)\n", LM_VERSION, LM_DATE);
377
378	if (sis630_initialized) {
379	printk(KERN_ERR "i2c-sis630.o: Oops, sis630_init called a second time!\n");
380	return -EBUSY;
381	}
382
383	sis630_initialized = 0;
384	if ((res = sis630_setup())) {
385	printk(KERN_ERR "i2c-sis630.o: SIS630 not detected, module not inserted.\n");
386	i2c_sis630_cleanup();
387	return res;
388	}
389	sis630_initialized++;
390	sprintf(sis630_adapter.name, "SMBus SIS630 adapter at %04x",
391	acpi_base + SMB_STS);
392	if ((res = i2c_add_adapter(&sis630_adapter))) {
393	printk(KERN_ERR "i2c-sis630.o: Adapter registration failed, "
394	"module not inserted.\n");
395	i2c_sis630_cleanup();
396	return res;
397	}
398	sis630_initialized++;
399	printk(KERN_INFO "i2c-sis630.o: SIS630 bus detected and initialized\n");
400
401	return 0;
402	}
403
404	int __init i2c_sis630_cleanup(void) {
405	int res;
406	if (sis630_initialized >= 2) {
407	if ((res = i2c_del_adapter(&sis630_adapter))) {
408	printk(KERN_ERR "i2c-sis630.o: i2c_del_adapter failed, module not"
409	"removed\n");
410	return res;
411	} else
412	sis630_initialized--;
413	}
414	if (sis630_initialized >= 1) {
415	release_region(acpi_base + SMB_STS, SIS630_SMB_IOREGION);
416	sis630_initialized--;
417	}
418	return 0;
419	}
420
421
422	EXPORT_NO_SYMBOLS;
423
424	#ifdef MODULE_LICENSE
425	MODULE_LICENSE("GPL");
426	#endif
427
428	#ifdef MODULE
429	MODULE_AUTHOR("Alexander Malysh <amalysh@web.de>");
430	MODULE_DESCRIPTION("SIS630 SMBus driver");
431
432	int init_module(void) {
433	return i2c_sis630_init();
434	}
435
436	int cleanup_module(void) {
437	return i2c_sis630_cleanup();
438	}
439
440	#endif /* MODULE */

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