1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2015 - 2016 Red Hat, Inc
4 * Copyright (c) 2011, 2012 Synaptics Incorporated
5 * Copyright (c) 2011 Unixphere
6 */
7
8 #include <linux/kernel.h>
9 #include <linux/delay.h>
10 #include <linux/i2c.h>
11 #include <linux/interrupt.h>
12 #include <linux/kconfig.h>
13 #include <linux/lockdep.h>
14 #include <linux/module.h>
15 #include <linux/pm.h>
16 #include <linux/rmi.h>
17 #include <linux/slab.h>
18 #include "rmi_driver.h"
19
20 #define SMB_PROTOCOL_VERSION_ADDRESS 0xfd
21 #define SMB_MAX_COUNT 32
22 #define RMI_SMB2_MAP_SIZE 8 /* 8 entry of 4 bytes each */
23 #define RMI_SMB2_MAP_FLAGS_WE 0x01
24
25 struct mapping_table_entry {
26 __le16 rmiaddr;
27 u8 readcount;
28 u8 flags;
29 };
30
31 struct rmi_smb_xport {
32 struct rmi_transport_dev xport;
33 struct i2c_client *client;
34
35 struct mutex page_mutex;
36 int page;
37 u8 table_index;
38 struct mutex mappingtable_mutex;
39 struct mapping_table_entry mapping_table[RMI_SMB2_MAP_SIZE];
40 };
41
rmi_smb_get_version(struct rmi_smb_xport * rmi_smb)42 static int rmi_smb_get_version(struct rmi_smb_xport *rmi_smb)
43 {
44 struct i2c_client *client = rmi_smb->client;
45 int retval;
46
47 /* Check if for SMBus new version device by reading version byte. */
48 retval = i2c_smbus_read_byte_data(client, SMB_PROTOCOL_VERSION_ADDRESS);
49 if (retval < 0) {
50 dev_err(&client->dev, "failed to get SMBus version number!\n");
51 return retval;
52 }
53
54 return retval + 1;
55 }
56
57 /* SMB block write - wrapper over ic2_smb_write_block */
smb_block_write(struct rmi_transport_dev * xport,u8 commandcode,const void * buf,size_t len)58 static int smb_block_write(struct rmi_transport_dev *xport,
59 u8 commandcode, const void *buf, size_t len)
60 {
61 struct rmi_smb_xport *rmi_smb =
62 container_of(xport, struct rmi_smb_xport, xport);
63 struct i2c_client *client = rmi_smb->client;
64 int retval;
65
66 retval = i2c_smbus_write_block_data(client, commandcode, len, buf);
67
68 rmi_dbg(RMI_DEBUG_XPORT, &client->dev,
69 "wrote %zd bytes at %#04x: %d (%*ph)\n",
70 len, commandcode, retval, (int)len, buf);
71
72 return retval;
73 }
74
75 /*
76 * The function to get command code for smbus operations and keeps
77 * records to the driver mapping table
78 */
rmi_smb_get_command_code(struct rmi_transport_dev * xport,u16 rmiaddr,int bytecount,bool isread,u8 * commandcode)79 static int rmi_smb_get_command_code(struct rmi_transport_dev *xport,
80 u16 rmiaddr, int bytecount, bool isread, u8 *commandcode)
81 {
82 struct rmi_smb_xport *rmi_smb =
83 container_of(xport, struct rmi_smb_xport, xport);
84 struct mapping_table_entry new_map;
85 int i;
86 int retval = 0;
87
88 mutex_lock(&rmi_smb->mappingtable_mutex);
89
90 for (i = 0; i < RMI_SMB2_MAP_SIZE; i++) {
91 struct mapping_table_entry *entry = &rmi_smb->mapping_table[i];
92
93 if (le16_to_cpu(entry->rmiaddr) == rmiaddr) {
94 if (isread) {
95 if (entry->readcount == bytecount)
96 goto exit;
97 } else {
98 if (entry->flags & RMI_SMB2_MAP_FLAGS_WE) {
99 goto exit;
100 }
101 }
102 }
103 }
104
105 i = rmi_smb->table_index;
106 rmi_smb->table_index = (i + 1) % RMI_SMB2_MAP_SIZE;
107
108 /* constructs mapping table data entry. 4 bytes each entry */
109 memset(&new_map, 0, sizeof(new_map));
110 new_map.rmiaddr = cpu_to_le16(rmiaddr);
111 new_map.readcount = bytecount;
112 new_map.flags = !isread ? RMI_SMB2_MAP_FLAGS_WE : 0;
113
114 retval = smb_block_write(xport, i + 0x80, &new_map, sizeof(new_map));
115 if (retval < 0) {
116 /*
117 * if not written to device mapping table
118 * clear the driver mapping table records
119 */
120 memset(&new_map, 0, sizeof(new_map));
121 }
122
123 /* save to the driver level mapping table */
124 rmi_smb->mapping_table[i] = new_map;
125
126 exit:
127 mutex_unlock(&rmi_smb->mappingtable_mutex);
128
129 if (retval < 0)
130 return retval;
131
132 *commandcode = i;
133 return 0;
134 }
135
rmi_smb_write_block(struct rmi_transport_dev * xport,u16 rmiaddr,const void * databuff,size_t len)136 static int rmi_smb_write_block(struct rmi_transport_dev *xport, u16 rmiaddr,
137 const void *databuff, size_t len)
138 {
139 int retval = 0;
140 u8 commandcode;
141 struct rmi_smb_xport *rmi_smb =
142 container_of(xport, struct rmi_smb_xport, xport);
143 int cur_len = (int)len;
144
145 mutex_lock(&rmi_smb->page_mutex);
146
147 while (cur_len > 0) {
148 /*
149 * break into 32 bytes chunks to write get command code
150 */
151 int block_len = min_t(int, len, SMB_MAX_COUNT);
152
153 retval = rmi_smb_get_command_code(xport, rmiaddr, block_len,
154 false, &commandcode);
155 if (retval < 0)
156 goto exit;
157
158 retval = smb_block_write(xport, commandcode,
159 databuff, block_len);
160 if (retval < 0)
161 goto exit;
162
163 /* prepare to write next block of bytes */
164 cur_len -= SMB_MAX_COUNT;
165 databuff += SMB_MAX_COUNT;
166 rmiaddr += SMB_MAX_COUNT;
167 }
168 exit:
169 mutex_unlock(&rmi_smb->page_mutex);
170 return retval;
171 }
172
173 /* SMB block read - wrapper over ic2_smb_read_block */
smb_block_read(struct rmi_transport_dev * xport,u8 commandcode,void * buf,size_t len)174 static int smb_block_read(struct rmi_transport_dev *xport,
175 u8 commandcode, void *buf, size_t len)
176 {
177 struct rmi_smb_xport *rmi_smb =
178 container_of(xport, struct rmi_smb_xport, xport);
179 struct i2c_client *client = rmi_smb->client;
180 int retval;
181
182 retval = i2c_smbus_read_block_data(client, commandcode, buf);
183 if (retval < 0)
184 return retval;
185
186 return retval;
187 }
188
rmi_smb_read_block(struct rmi_transport_dev * xport,u16 rmiaddr,void * databuff,size_t len)189 static int rmi_smb_read_block(struct rmi_transport_dev *xport, u16 rmiaddr,
190 void *databuff, size_t len)
191 {
192 struct rmi_smb_xport *rmi_smb =
193 container_of(xport, struct rmi_smb_xport, xport);
194 int retval;
195 u8 commandcode;
196 int cur_len = (int)len;
197
198 mutex_lock(&rmi_smb->page_mutex);
199 memset(databuff, 0, len);
200
201 while (cur_len > 0) {
202 /* break into 32 bytes chunks to write get command code */
203 int block_len = min_t(int, cur_len, SMB_MAX_COUNT);
204
205 retval = rmi_smb_get_command_code(xport, rmiaddr, block_len,
206 true, &commandcode);
207 if (retval < 0)
208 goto exit;
209
210 retval = smb_block_read(xport, commandcode,
211 databuff, block_len);
212 if (retval < 0)
213 goto exit;
214
215 /* prepare to read next block of bytes */
216 cur_len -= SMB_MAX_COUNT;
217 databuff += SMB_MAX_COUNT;
218 rmiaddr += SMB_MAX_COUNT;
219 }
220
221 retval = 0;
222
223 exit:
224 mutex_unlock(&rmi_smb->page_mutex);
225 return retval;
226 }
227
rmi_smb_clear_state(struct rmi_smb_xport * rmi_smb)228 static void rmi_smb_clear_state(struct rmi_smb_xport *rmi_smb)
229 {
230 /* the mapping table has been flushed, discard the current one */
231 mutex_lock(&rmi_smb->mappingtable_mutex);
232 memset(rmi_smb->mapping_table, 0, sizeof(rmi_smb->mapping_table));
233 mutex_unlock(&rmi_smb->mappingtable_mutex);
234 }
235
rmi_smb_enable_smbus_mode(struct rmi_smb_xport * rmi_smb)236 static int rmi_smb_enable_smbus_mode(struct rmi_smb_xport *rmi_smb)
237 {
238 struct i2c_client *client = rmi_smb->client;
239 int smbus_version;
240
241 /*
242 * psmouse driver resets the controller, we only need to wait
243 * to give the firmware chance to fully reinitialize.
244 */
245 if (rmi_smb->xport.pdata.reset_delay_ms)
246 msleep(rmi_smb->xport.pdata.reset_delay_ms);
247
248 /* we need to get the smbus version to activate the touchpad */
249 smbus_version = rmi_smb_get_version(rmi_smb);
250 if (smbus_version < 0)
251 return smbus_version;
252
253 rmi_dbg(RMI_DEBUG_XPORT, &client->dev, "Smbus version is %d",
254 smbus_version);
255
256 if (smbus_version != 2 && smbus_version != 3) {
257 dev_err(&client->dev, "Unrecognized SMB version %d\n",
258 smbus_version);
259 return -ENODEV;
260 }
261
262 return 0;
263 }
264
rmi_smb_reset(struct rmi_transport_dev * xport,u16 reset_addr)265 static int rmi_smb_reset(struct rmi_transport_dev *xport, u16 reset_addr)
266 {
267 struct rmi_smb_xport *rmi_smb =
268 container_of(xport, struct rmi_smb_xport, xport);
269
270 rmi_smb_clear_state(rmi_smb);
271
272 /*
273 * We do not call the actual reset command, it has to be handled in
274 * PS/2 or there will be races between PS/2 and SMBus. PS/2 should
275 * ensure that a psmouse_reset is called before initializing the
276 * device and after it has been removed to be in a known state.
277 */
278 return rmi_smb_enable_smbus_mode(rmi_smb);
279 }
280
281 static const struct rmi_transport_ops rmi_smb_ops = {
282 .write_block = rmi_smb_write_block,
283 .read_block = rmi_smb_read_block,
284 .reset = rmi_smb_reset,
285 };
286
rmi_smb_probe(struct i2c_client * client,const struct i2c_device_id * id)287 static int rmi_smb_probe(struct i2c_client *client,
288 const struct i2c_device_id *id)
289 {
290 struct rmi_device_platform_data *pdata = dev_get_platdata(&client->dev);
291 struct rmi_smb_xport *rmi_smb;
292 int error;
293
294 if (!pdata) {
295 dev_err(&client->dev, "no platform data, aborting\n");
296 return -ENOMEM;
297 }
298
299 if (!i2c_check_functionality(client->adapter,
300 I2C_FUNC_SMBUS_READ_BLOCK_DATA |
301 I2C_FUNC_SMBUS_HOST_NOTIFY)) {
302 dev_err(&client->dev,
303 "adapter does not support required functionality\n");
304 return -ENODEV;
305 }
306
307 if (client->irq <= 0) {
308 dev_err(&client->dev, "no IRQ provided, giving up\n");
309 return client->irq ? client->irq : -ENODEV;
310 }
311
312 rmi_smb = devm_kzalloc(&client->dev, sizeof(struct rmi_smb_xport),
313 GFP_KERNEL);
314 if (!rmi_smb)
315 return -ENOMEM;
316
317 rmi_dbg(RMI_DEBUG_XPORT, &client->dev, "Probing %s\n",
318 dev_name(&client->dev));
319
320 rmi_smb->client = client;
321 mutex_init(&rmi_smb->page_mutex);
322 mutex_init(&rmi_smb->mappingtable_mutex);
323
324 rmi_smb->xport.dev = &client->dev;
325 rmi_smb->xport.pdata = *pdata;
326 rmi_smb->xport.pdata.irq = client->irq;
327 rmi_smb->xport.proto_name = "smb";
328 rmi_smb->xport.ops = &rmi_smb_ops;
329
330 error = rmi_smb_enable_smbus_mode(rmi_smb);
331 if (error)
332 return error;
333
334 i2c_set_clientdata(client, rmi_smb);
335
336 dev_info(&client->dev, "registering SMbus-connected sensor\n");
337
338 error = rmi_register_transport_device(&rmi_smb->xport);
339 if (error) {
340 dev_err(&client->dev, "failed to register sensor: %d\n", error);
341 return error;
342 }
343
344 return 0;
345 }
346
rmi_smb_remove(struct i2c_client * client)347 static int rmi_smb_remove(struct i2c_client *client)
348 {
349 struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
350
351 rmi_unregister_transport_device(&rmi_smb->xport);
352
353 return 0;
354 }
355
rmi_smb_suspend(struct device * dev)356 static int __maybe_unused rmi_smb_suspend(struct device *dev)
357 {
358 struct i2c_client *client = to_i2c_client(dev);
359 struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
360 int ret;
361
362 ret = rmi_driver_suspend(rmi_smb->xport.rmi_dev, true);
363 if (ret)
364 dev_warn(dev, "Failed to suspend device: %d\n", ret);
365
366 return ret;
367 }
368
rmi_smb_runtime_suspend(struct device * dev)369 static int __maybe_unused rmi_smb_runtime_suspend(struct device *dev)
370 {
371 struct i2c_client *client = to_i2c_client(dev);
372 struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
373 int ret;
374
375 ret = rmi_driver_suspend(rmi_smb->xport.rmi_dev, false);
376 if (ret)
377 dev_warn(dev, "Failed to suspend device: %d\n", ret);
378
379 return ret;
380 }
381
rmi_smb_resume(struct device * dev)382 static int __maybe_unused rmi_smb_resume(struct device *dev)
383 {
384 struct i2c_client *client = container_of(dev, struct i2c_client, dev);
385 struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
386 struct rmi_device *rmi_dev = rmi_smb->xport.rmi_dev;
387 int ret;
388
389 rmi_smb_reset(&rmi_smb->xport, 0);
390
391 rmi_reset(rmi_dev);
392
393 ret = rmi_driver_resume(rmi_smb->xport.rmi_dev, true);
394 if (ret)
395 dev_warn(dev, "Failed to resume device: %d\n", ret);
396
397 return 0;
398 }
399
rmi_smb_runtime_resume(struct device * dev)400 static int __maybe_unused rmi_smb_runtime_resume(struct device *dev)
401 {
402 struct i2c_client *client = to_i2c_client(dev);
403 struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
404 int ret;
405
406 ret = rmi_driver_resume(rmi_smb->xport.rmi_dev, false);
407 if (ret)
408 dev_warn(dev, "Failed to resume device: %d\n", ret);
409
410 return 0;
411 }
412
413 static const struct dev_pm_ops rmi_smb_pm = {
414 SET_SYSTEM_SLEEP_PM_OPS(rmi_smb_suspend, rmi_smb_resume)
415 SET_RUNTIME_PM_OPS(rmi_smb_runtime_suspend, rmi_smb_runtime_resume,
416 NULL)
417 };
418
419 static const struct i2c_device_id rmi_id[] = {
420 { "rmi4_smbus", 0 },
421 { }
422 };
423 MODULE_DEVICE_TABLE(i2c, rmi_id);
424
425 static struct i2c_driver rmi_smb_driver = {
426 .driver = {
427 .name = "rmi4_smbus",
428 .pm = &rmi_smb_pm,
429 },
430 .id_table = rmi_id,
431 .probe = rmi_smb_probe,
432 .remove = rmi_smb_remove,
433 };
434
435 module_i2c_driver(rmi_smb_driver);
436
437 MODULE_AUTHOR("Andrew Duggan <aduggan@synaptics.com>");
438 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@redhat.com>");
439 MODULE_DESCRIPTION("RMI4 SMBus driver");
440 MODULE_LICENSE("GPL");
441