1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2006-2007 PA Semi, Inc
5 * SMBus host driver for PA Semi PWRficient
8 #include <linux/module.h>
10 #include <linux/kernel.h>
11 #include <linux/stddef.h>
12 #include <linux/sched.h>
13 #include <linux/i2c.h>
14 #include <linux/delay.h>
15 #include <linux/slab.h>
18 static struct pci_driver pasemi_smb_driver
;
22 struct i2c_adapter adapter
;
27 /* Register offsets */
28 #define REG_MTXFIFO 0x00
29 #define REG_MRXFIFO 0x04
30 #define REG_SMSTA 0x14
34 #define MTXFIFO_READ 0x00000400
35 #define MTXFIFO_STOP 0x00000200
36 #define MTXFIFO_START 0x00000100
37 #define MTXFIFO_DATA_M 0x000000ff
39 #define MRXFIFO_EMPTY 0x00000100
40 #define MRXFIFO_DATA_M 0x000000ff
42 #define SMSTA_XEN 0x08000000
43 #define SMSTA_MTN 0x00200000
45 #define CTL_MRR 0x00000400
46 #define CTL_MTR 0x00000200
47 #define CTL_CLK_M 0x000000ff
49 #define CLK_100K_DIV 84
50 #define CLK_400K_DIV 21
52 static inline void reg_write(struct pasemi_smbus
*smbus
, int reg
, int val
)
54 dev_dbg(&smbus
->dev
->dev
, "smbus write reg %lx val %08x\n",
55 smbus
->base
+ reg
, val
);
56 outl(val
, smbus
->base
+ reg
);
59 static inline int reg_read(struct pasemi_smbus
*smbus
, int reg
)
62 ret
= inl(smbus
->base
+ reg
);
63 dev_dbg(&smbus
->dev
->dev
, "smbus read reg %lx val %08x\n",
64 smbus
->base
+ reg
, ret
);
68 #define TXFIFO_WR(smbus, reg) reg_write((smbus), REG_MTXFIFO, (reg))
69 #define RXFIFO_RD(smbus) reg_read((smbus), REG_MRXFIFO)
71 static void pasemi_smb_clear(struct pasemi_smbus
*smbus
)
75 status
= reg_read(smbus
, REG_SMSTA
);
76 reg_write(smbus
, REG_SMSTA
, status
);
79 static int pasemi_smb_waitready(struct pasemi_smbus
*smbus
)
84 status
= reg_read(smbus
, REG_SMSTA
);
86 while (!(status
& SMSTA_XEN
) && timeout
--) {
88 status
= reg_read(smbus
, REG_SMSTA
);
92 if (status
& SMSTA_MTN
)
96 dev_warn(&smbus
->dev
->dev
, "Timeout, status 0x%08x\n", status
);
97 reg_write(smbus
, REG_SMSTA
, status
);
102 reg_write(smbus
, REG_SMSTA
, SMSTA_XEN
);
107 static int pasemi_i2c_xfer_msg(struct i2c_adapter
*adapter
,
108 struct i2c_msg
*msg
, int stop
)
110 struct pasemi_smbus
*smbus
= adapter
->algo_data
;
114 read
= msg
->flags
& I2C_M_RD
? 1 : 0;
116 TXFIFO_WR(smbus
, MTXFIFO_START
| i2c_8bit_addr_from_msg(msg
));
119 TXFIFO_WR(smbus
, msg
->len
| MTXFIFO_READ
|
120 (stop
? MTXFIFO_STOP
: 0));
122 err
= pasemi_smb_waitready(smbus
);
126 for (i
= 0; i
< msg
->len
; i
++) {
127 rd
= RXFIFO_RD(smbus
);
128 if (rd
& MRXFIFO_EMPTY
) {
132 msg
->buf
[i
] = rd
& MRXFIFO_DATA_M
;
135 for (i
= 0; i
< msg
->len
- 1; i
++)
136 TXFIFO_WR(smbus
, msg
->buf
[i
]);
138 TXFIFO_WR(smbus
, msg
->buf
[msg
->len
-1] |
139 (stop
? MTXFIFO_STOP
: 0));
142 err
= pasemi_smb_waitready(smbus
);
151 reg_write(smbus
, REG_CTL
, (CTL_MTR
| CTL_MRR
|
152 (CLK_100K_DIV
& CTL_CLK_M
)));
156 static int pasemi_i2c_xfer(struct i2c_adapter
*adapter
,
157 struct i2c_msg
*msgs
, int num
)
159 struct pasemi_smbus
*smbus
= adapter
->algo_data
;
162 pasemi_smb_clear(smbus
);
166 for (i
= 0; i
< num
&& !ret
; i
++)
167 ret
= pasemi_i2c_xfer_msg(adapter
, &msgs
[i
], (i
== (num
- 1)));
169 return ret
? ret
: num
;
172 static int pasemi_smb_xfer(struct i2c_adapter
*adapter
,
173 u16 addr
, unsigned short flags
, char read_write
, u8 command
,
174 int size
, union i2c_smbus_data
*data
)
176 struct pasemi_smbus
*smbus
= adapter
->algo_data
;
181 /* All our ops take 8-bit shifted addresses */
183 read_flag
= read_write
== I2C_SMBUS_READ
;
185 pasemi_smb_clear(smbus
);
188 case I2C_SMBUS_QUICK
:
189 TXFIFO_WR(smbus
, addr
| read_flag
| MTXFIFO_START
|
193 TXFIFO_WR(smbus
, addr
| read_flag
| MTXFIFO_START
);
195 TXFIFO_WR(smbus
, 1 | MTXFIFO_STOP
| MTXFIFO_READ
);
197 TXFIFO_WR(smbus
, MTXFIFO_STOP
| command
);
199 case I2C_SMBUS_BYTE_DATA
:
200 TXFIFO_WR(smbus
, addr
| MTXFIFO_START
);
201 TXFIFO_WR(smbus
, command
);
203 TXFIFO_WR(smbus
, addr
| I2C_SMBUS_READ
| MTXFIFO_START
);
204 TXFIFO_WR(smbus
, 1 | MTXFIFO_READ
| MTXFIFO_STOP
);
206 TXFIFO_WR(smbus
, MTXFIFO_STOP
| data
->byte
);
209 case I2C_SMBUS_WORD_DATA
:
210 TXFIFO_WR(smbus
, addr
| MTXFIFO_START
);
211 TXFIFO_WR(smbus
, command
);
213 TXFIFO_WR(smbus
, addr
| I2C_SMBUS_READ
| MTXFIFO_START
);
214 TXFIFO_WR(smbus
, 2 | MTXFIFO_READ
| MTXFIFO_STOP
);
216 TXFIFO_WR(smbus
, data
->word
& MTXFIFO_DATA_M
);
217 TXFIFO_WR(smbus
, MTXFIFO_STOP
| (data
->word
>> 8));
220 case I2C_SMBUS_BLOCK_DATA
:
221 TXFIFO_WR(smbus
, addr
| MTXFIFO_START
);
222 TXFIFO_WR(smbus
, command
);
224 TXFIFO_WR(smbus
, addr
| I2C_SMBUS_READ
| MTXFIFO_START
);
225 TXFIFO_WR(smbus
, 1 | MTXFIFO_READ
);
226 rd
= RXFIFO_RD(smbus
);
227 len
= min_t(u8
, (rd
& MRXFIFO_DATA_M
),
228 I2C_SMBUS_BLOCK_MAX
);
229 TXFIFO_WR(smbus
, len
| MTXFIFO_READ
|
232 len
= min_t(u8
, data
->block
[0], I2C_SMBUS_BLOCK_MAX
);
233 TXFIFO_WR(smbus
, len
);
234 for (i
= 1; i
< len
; i
++)
235 TXFIFO_WR(smbus
, data
->block
[i
]);
236 TXFIFO_WR(smbus
, data
->block
[len
] | MTXFIFO_STOP
);
239 case I2C_SMBUS_PROC_CALL
:
240 read_write
= I2C_SMBUS_READ
;
241 TXFIFO_WR(smbus
, addr
| MTXFIFO_START
);
242 TXFIFO_WR(smbus
, command
);
243 TXFIFO_WR(smbus
, data
->word
& MTXFIFO_DATA_M
);
244 TXFIFO_WR(smbus
, (data
->word
>> 8) & MTXFIFO_DATA_M
);
245 TXFIFO_WR(smbus
, addr
| I2C_SMBUS_READ
| MTXFIFO_START
);
246 TXFIFO_WR(smbus
, 2 | MTXFIFO_STOP
| MTXFIFO_READ
);
248 case I2C_SMBUS_BLOCK_PROC_CALL
:
249 len
= min_t(u8
, data
->block
[0], I2C_SMBUS_BLOCK_MAX
- 1);
250 read_write
= I2C_SMBUS_READ
;
251 TXFIFO_WR(smbus
, addr
| MTXFIFO_START
);
252 TXFIFO_WR(smbus
, command
);
253 TXFIFO_WR(smbus
, len
);
254 for (i
= 1; i
<= len
; i
++)
255 TXFIFO_WR(smbus
, data
->block
[i
]);
256 TXFIFO_WR(smbus
, addr
| I2C_SMBUS_READ
);
257 TXFIFO_WR(smbus
, MTXFIFO_READ
| 1);
258 rd
= RXFIFO_RD(smbus
);
259 len
= min_t(u8
, (rd
& MRXFIFO_DATA_M
),
260 I2C_SMBUS_BLOCK_MAX
- len
);
261 TXFIFO_WR(smbus
, len
| MTXFIFO_READ
| MTXFIFO_STOP
);
265 dev_warn(&adapter
->dev
, "Unsupported transaction %d\n", size
);
269 err
= pasemi_smb_waitready(smbus
);
273 if (read_write
== I2C_SMBUS_WRITE
)
278 case I2C_SMBUS_BYTE_DATA
:
279 rd
= RXFIFO_RD(smbus
);
280 if (rd
& MRXFIFO_EMPTY
) {
284 data
->byte
= rd
& MRXFIFO_DATA_M
;
286 case I2C_SMBUS_WORD_DATA
:
287 case I2C_SMBUS_PROC_CALL
:
288 rd
= RXFIFO_RD(smbus
);
289 if (rd
& MRXFIFO_EMPTY
) {
293 data
->word
= rd
& MRXFIFO_DATA_M
;
294 rd
= RXFIFO_RD(smbus
);
295 if (rd
& MRXFIFO_EMPTY
) {
299 data
->word
|= (rd
& MRXFIFO_DATA_M
) << 8;
301 case I2C_SMBUS_BLOCK_DATA
:
302 case I2C_SMBUS_BLOCK_PROC_CALL
:
303 data
->block
[0] = len
;
304 for (i
= 1; i
<= len
; i
++) {
305 rd
= RXFIFO_RD(smbus
);
306 if (rd
& MRXFIFO_EMPTY
) {
310 data
->block
[i
] = rd
& MRXFIFO_DATA_M
;
318 reg_write(smbus
, REG_CTL
, (CTL_MTR
| CTL_MRR
|
319 (CLK_100K_DIV
& CTL_CLK_M
)));
323 static u32
pasemi_smb_func(struct i2c_adapter
*adapter
)
325 return I2C_FUNC_SMBUS_QUICK
| I2C_FUNC_SMBUS_BYTE
|
326 I2C_FUNC_SMBUS_BYTE_DATA
| I2C_FUNC_SMBUS_WORD_DATA
|
327 I2C_FUNC_SMBUS_BLOCK_DATA
| I2C_FUNC_SMBUS_PROC_CALL
|
328 I2C_FUNC_SMBUS_BLOCK_PROC_CALL
| I2C_FUNC_I2C
;
331 static const struct i2c_algorithm smbus_algorithm
= {
332 .master_xfer
= pasemi_i2c_xfer
,
333 .smbus_xfer
= pasemi_smb_xfer
,
334 .functionality
= pasemi_smb_func
,
337 static int pasemi_smb_probe(struct pci_dev
*dev
,
338 const struct pci_device_id
*id
)
340 struct pasemi_smbus
*smbus
;
343 if (!(pci_resource_flags(dev
, 0) & IORESOURCE_IO
))
346 smbus
= kzalloc(sizeof(struct pasemi_smbus
), GFP_KERNEL
);
351 smbus
->base
= pci_resource_start(dev
, 0);
352 smbus
->size
= pci_resource_len(dev
, 0);
354 if (!request_region(smbus
->base
, smbus
->size
,
355 pasemi_smb_driver
.name
)) {
360 smbus
->adapter
.owner
= THIS_MODULE
;
361 snprintf(smbus
->adapter
.name
, sizeof(smbus
->adapter
.name
),
362 "PA Semi SMBus adapter at 0x%lx", smbus
->base
);
363 smbus
->adapter
.class = I2C_CLASS_HWMON
| I2C_CLASS_SPD
;
364 smbus
->adapter
.algo
= &smbus_algorithm
;
365 smbus
->adapter
.algo_data
= smbus
;
367 /* set up the sysfs linkage to our parent device */
368 smbus
->adapter
.dev
.parent
= &dev
->dev
;
370 reg_write(smbus
, REG_CTL
, (CTL_MTR
| CTL_MRR
|
371 (CLK_100K_DIV
& CTL_CLK_M
)));
373 error
= i2c_add_adapter(&smbus
->adapter
);
375 goto out_release_region
;
377 pci_set_drvdata(dev
, smbus
);
382 release_region(smbus
->base
, smbus
->size
);
388 static void pasemi_smb_remove(struct pci_dev
*dev
)
390 struct pasemi_smbus
*smbus
= pci_get_drvdata(dev
);
392 i2c_del_adapter(&smbus
->adapter
);
393 release_region(smbus
->base
, smbus
->size
);
397 static const struct pci_device_id pasemi_smb_ids
[] = {
398 { PCI_DEVICE(0x1959, 0xa003) },
402 MODULE_DEVICE_TABLE(pci
, pasemi_smb_ids
);
404 static struct pci_driver pasemi_smb_driver
= {
405 .name
= "i2c-pasemi",
406 .id_table
= pasemi_smb_ids
,
407 .probe
= pasemi_smb_probe
,
408 .remove
= pasemi_smb_remove
,
411 module_pci_driver(pasemi_smb_driver
);
413 MODULE_LICENSE("GPL");
414 MODULE_AUTHOR ("Olof Johansson <olof@lixom.net>");
415 MODULE_DESCRIPTION("PA Semi PWRficient SMBus driver");