1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Copyright (c) 2011-2016 Synaptics Incorporated |
4 | * Copyright (c) 2011 Unixphere |
5 | */ |
6 | |
7 | #include <linux/i2c.h> |
8 | #include <linux/rmi.h> |
9 | #include <linux/of.h> |
10 | #include <linux/delay.h> |
11 | #include <linux/regulator/consumer.h> |
12 | #include "rmi_driver.h" |
13 | |
14 | #define BUFFER_SIZE_INCREMENT 32 |
15 | |
16 | /** |
17 | * struct rmi_i2c_xport - stores information for i2c communication |
18 | * |
19 | * @xport: The transport interface structure |
20 | * @client: The I2C client device structure |
21 | * |
22 | * @page_mutex: Locks current page to avoid changing pages in unexpected ways. |
23 | * @page: Keeps track of the current virtual page |
24 | * |
25 | * @tx_buf: Buffer used for transmitting data to the sensor over i2c. |
26 | * @tx_buf_size: Size of the buffer |
27 | * |
28 | * @supplies: Array of voltage regulators |
29 | * @startup_delay: Milliseconds to pause after powering up the regulators |
30 | */ |
31 | struct rmi_i2c_xport { |
32 | struct rmi_transport_dev xport; |
33 | struct i2c_client *client; |
34 | |
35 | struct mutex page_mutex; |
36 | int page; |
37 | |
38 | u8 *tx_buf; |
39 | size_t tx_buf_size; |
40 | |
41 | struct regulator_bulk_data supplies[2]; |
42 | u32 startup_delay; |
43 | }; |
44 | |
45 | #define RMI_PAGE_SELECT_REGISTER 0xff |
46 | #define RMI_I2C_PAGE(addr) (((addr) >> 8) & 0xff) |
47 | |
48 | /* |
49 | * rmi_set_page - Set RMI page |
50 | * @xport: The pointer to the rmi_transport_dev struct |
51 | * @page: The new page address. |
52 | * |
53 | * RMI devices have 16-bit addressing, but some of the transport |
54 | * implementations (like SMBus) only have 8-bit addressing. So RMI implements |
55 | * a page address at 0xff of every page so we can reliable page addresses |
56 | * every 256 registers. |
57 | * |
58 | * The page_mutex lock must be held when this function is entered. |
59 | * |
60 | * Returns zero on success, non-zero on failure. |
61 | */ |
62 | static int rmi_set_page(struct rmi_i2c_xport *rmi_i2c, u8 page) |
63 | { |
64 | struct i2c_client *client = rmi_i2c->client; |
65 | u8 txbuf[2] = {RMI_PAGE_SELECT_REGISTER, page}; |
66 | int retval; |
67 | |
68 | retval = i2c_master_send(client, buf: txbuf, count: sizeof(txbuf)); |
69 | if (retval != sizeof(txbuf)) { |
70 | dev_err(&client->dev, |
71 | "%s: set page failed: %d." , __func__, retval); |
72 | return (retval < 0) ? retval : -EIO; |
73 | } |
74 | |
75 | rmi_i2c->page = page; |
76 | return 0; |
77 | } |
78 | |
79 | static int rmi_i2c_write_block(struct rmi_transport_dev *xport, u16 addr, |
80 | const void *buf, size_t len) |
81 | { |
82 | struct rmi_i2c_xport *rmi_i2c = |
83 | container_of(xport, struct rmi_i2c_xport, xport); |
84 | struct i2c_client *client = rmi_i2c->client; |
85 | size_t tx_size = len + 1; |
86 | int retval; |
87 | |
88 | mutex_lock(&rmi_i2c->page_mutex); |
89 | |
90 | if (!rmi_i2c->tx_buf || rmi_i2c->tx_buf_size < tx_size) { |
91 | if (rmi_i2c->tx_buf) |
92 | devm_kfree(dev: &client->dev, p: rmi_i2c->tx_buf); |
93 | rmi_i2c->tx_buf_size = tx_size + BUFFER_SIZE_INCREMENT; |
94 | rmi_i2c->tx_buf = devm_kzalloc(dev: &client->dev, |
95 | size: rmi_i2c->tx_buf_size, |
96 | GFP_KERNEL); |
97 | if (!rmi_i2c->tx_buf) { |
98 | rmi_i2c->tx_buf_size = 0; |
99 | retval = -ENOMEM; |
100 | goto exit; |
101 | } |
102 | } |
103 | |
104 | rmi_i2c->tx_buf[0] = addr & 0xff; |
105 | memcpy(rmi_i2c->tx_buf + 1, buf, len); |
106 | |
107 | if (RMI_I2C_PAGE(addr) != rmi_i2c->page) { |
108 | retval = rmi_set_page(rmi_i2c, RMI_I2C_PAGE(addr)); |
109 | if (retval) |
110 | goto exit; |
111 | } |
112 | |
113 | retval = i2c_master_send(client, buf: rmi_i2c->tx_buf, count: tx_size); |
114 | if (retval == tx_size) |
115 | retval = 0; |
116 | else if (retval >= 0) |
117 | retval = -EIO; |
118 | |
119 | exit: |
120 | rmi_dbg(RMI_DEBUG_XPORT, dev: &client->dev, |
121 | fmt: "write %zd bytes at %#06x: %d (%*ph)\n" , |
122 | len, addr, retval, (int)len, buf); |
123 | |
124 | mutex_unlock(lock: &rmi_i2c->page_mutex); |
125 | return retval; |
126 | } |
127 | |
128 | static int rmi_i2c_read_block(struct rmi_transport_dev *xport, u16 addr, |
129 | void *buf, size_t len) |
130 | { |
131 | struct rmi_i2c_xport *rmi_i2c = |
132 | container_of(xport, struct rmi_i2c_xport, xport); |
133 | struct i2c_client *client = rmi_i2c->client; |
134 | u8 addr_offset = addr & 0xff; |
135 | int retval; |
136 | struct i2c_msg msgs[] = { |
137 | { |
138 | .addr = client->addr, |
139 | .len = sizeof(addr_offset), |
140 | .buf = &addr_offset, |
141 | }, |
142 | { |
143 | .addr = client->addr, |
144 | .flags = I2C_M_RD, |
145 | .len = len, |
146 | .buf = buf, |
147 | }, |
148 | }; |
149 | |
150 | mutex_lock(&rmi_i2c->page_mutex); |
151 | |
152 | if (RMI_I2C_PAGE(addr) != rmi_i2c->page) { |
153 | retval = rmi_set_page(rmi_i2c, RMI_I2C_PAGE(addr)); |
154 | if (retval) |
155 | goto exit; |
156 | } |
157 | |
158 | retval = i2c_transfer(adap: client->adapter, msgs, ARRAY_SIZE(msgs)); |
159 | if (retval == ARRAY_SIZE(msgs)) |
160 | retval = 0; /* success */ |
161 | else if (retval >= 0) |
162 | retval = -EIO; |
163 | |
164 | exit: |
165 | rmi_dbg(RMI_DEBUG_XPORT, dev: &client->dev, |
166 | fmt: "read %zd bytes at %#06x: %d (%*ph)\n" , |
167 | len, addr, retval, (int)len, buf); |
168 | |
169 | mutex_unlock(lock: &rmi_i2c->page_mutex); |
170 | return retval; |
171 | } |
172 | |
173 | static const struct rmi_transport_ops rmi_i2c_ops = { |
174 | .write_block = rmi_i2c_write_block, |
175 | .read_block = rmi_i2c_read_block, |
176 | }; |
177 | |
178 | #ifdef CONFIG_OF |
179 | static const struct of_device_id rmi_i2c_of_match[] = { |
180 | { .compatible = "syna,rmi4-i2c" }, |
181 | {}, |
182 | }; |
183 | MODULE_DEVICE_TABLE(of, rmi_i2c_of_match); |
184 | #endif |
185 | |
186 | static void rmi_i2c_regulator_bulk_disable(void *data) |
187 | { |
188 | struct rmi_i2c_xport *rmi_i2c = data; |
189 | |
190 | regulator_bulk_disable(ARRAY_SIZE(rmi_i2c->supplies), |
191 | consumers: rmi_i2c->supplies); |
192 | } |
193 | |
194 | static void rmi_i2c_unregister_transport(void *data) |
195 | { |
196 | struct rmi_i2c_xport *rmi_i2c = data; |
197 | |
198 | rmi_unregister_transport_device(xport: &rmi_i2c->xport); |
199 | } |
200 | |
201 | static int rmi_i2c_probe(struct i2c_client *client) |
202 | { |
203 | struct rmi_device_platform_data *pdata; |
204 | struct rmi_device_platform_data *client_pdata = |
205 | dev_get_platdata(dev: &client->dev); |
206 | struct rmi_i2c_xport *rmi_i2c; |
207 | int error; |
208 | |
209 | rmi_i2c = devm_kzalloc(dev: &client->dev, size: sizeof(struct rmi_i2c_xport), |
210 | GFP_KERNEL); |
211 | if (!rmi_i2c) |
212 | return -ENOMEM; |
213 | |
214 | pdata = &rmi_i2c->xport.pdata; |
215 | |
216 | if (!client->dev.of_node && client_pdata) |
217 | *pdata = *client_pdata; |
218 | |
219 | pdata->irq = client->irq; |
220 | |
221 | rmi_dbg(RMI_DEBUG_XPORT, dev: &client->dev, fmt: "Probing %s.\n" , |
222 | dev_name(dev: &client->dev)); |
223 | |
224 | if (!i2c_check_functionality(adap: client->adapter, I2C_FUNC_I2C)) { |
225 | dev_err(&client->dev, |
226 | "adapter does not support required functionality\n" ); |
227 | return -ENODEV; |
228 | } |
229 | |
230 | rmi_i2c->supplies[0].supply = "vdd" ; |
231 | rmi_i2c->supplies[1].supply = "vio" ; |
232 | error = devm_regulator_bulk_get(dev: &client->dev, |
233 | ARRAY_SIZE(rmi_i2c->supplies), |
234 | consumers: rmi_i2c->supplies); |
235 | if (error < 0) |
236 | return error; |
237 | |
238 | error = regulator_bulk_enable(ARRAY_SIZE(rmi_i2c->supplies), |
239 | consumers: rmi_i2c->supplies); |
240 | if (error < 0) |
241 | return error; |
242 | |
243 | error = devm_add_action_or_reset(&client->dev, |
244 | rmi_i2c_regulator_bulk_disable, |
245 | rmi_i2c); |
246 | if (error) |
247 | return error; |
248 | |
249 | of_property_read_u32(np: client->dev.of_node, propname: "syna,startup-delay-ms" , |
250 | out_value: &rmi_i2c->startup_delay); |
251 | |
252 | msleep(msecs: rmi_i2c->startup_delay); |
253 | |
254 | rmi_i2c->client = client; |
255 | mutex_init(&rmi_i2c->page_mutex); |
256 | |
257 | rmi_i2c->xport.dev = &client->dev; |
258 | rmi_i2c->xport.proto_name = "i2c" ; |
259 | rmi_i2c->xport.ops = &rmi_i2c_ops; |
260 | |
261 | i2c_set_clientdata(client, data: rmi_i2c); |
262 | |
263 | /* |
264 | * Setting the page to zero will (a) make sure the PSR is in a |
265 | * known state, and (b) make sure we can talk to the device. |
266 | */ |
267 | error = rmi_set_page(rmi_i2c, page: 0); |
268 | if (error) { |
269 | dev_err(&client->dev, "Failed to set page select to 0\n" ); |
270 | return error; |
271 | } |
272 | |
273 | dev_info(&client->dev, "registering I2C-connected sensor\n" ); |
274 | |
275 | error = rmi_register_transport_device(xport: &rmi_i2c->xport); |
276 | if (error) { |
277 | dev_err(&client->dev, "failed to register sensor: %d\n" , error); |
278 | return error; |
279 | } |
280 | |
281 | error = devm_add_action_or_reset(&client->dev, |
282 | rmi_i2c_unregister_transport, |
283 | rmi_i2c); |
284 | if (error) |
285 | return error; |
286 | |
287 | return 0; |
288 | } |
289 | |
290 | static int rmi_i2c_suspend(struct device *dev) |
291 | { |
292 | struct i2c_client *client = to_i2c_client(dev); |
293 | struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client); |
294 | int ret; |
295 | |
296 | ret = rmi_driver_suspend(rmi_dev: rmi_i2c->xport.rmi_dev, enable_wake: true); |
297 | if (ret) |
298 | dev_warn(dev, "Failed to resume device: %d\n" , ret); |
299 | |
300 | regulator_bulk_disable(ARRAY_SIZE(rmi_i2c->supplies), |
301 | consumers: rmi_i2c->supplies); |
302 | |
303 | return ret; |
304 | } |
305 | |
306 | static int rmi_i2c_resume(struct device *dev) |
307 | { |
308 | struct i2c_client *client = to_i2c_client(dev); |
309 | struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client); |
310 | int ret; |
311 | |
312 | ret = regulator_bulk_enable(ARRAY_SIZE(rmi_i2c->supplies), |
313 | consumers: rmi_i2c->supplies); |
314 | if (ret) |
315 | return ret; |
316 | |
317 | msleep(msecs: rmi_i2c->startup_delay); |
318 | |
319 | ret = rmi_driver_resume(rmi_dev: rmi_i2c->xport.rmi_dev, clear_wake: true); |
320 | if (ret) |
321 | dev_warn(dev, "Failed to resume device: %d\n" , ret); |
322 | |
323 | return ret; |
324 | } |
325 | |
326 | static int rmi_i2c_runtime_suspend(struct device *dev) |
327 | { |
328 | struct i2c_client *client = to_i2c_client(dev); |
329 | struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client); |
330 | int ret; |
331 | |
332 | ret = rmi_driver_suspend(rmi_dev: rmi_i2c->xport.rmi_dev, enable_wake: false); |
333 | if (ret) |
334 | dev_warn(dev, "Failed to resume device: %d\n" , ret); |
335 | |
336 | regulator_bulk_disable(ARRAY_SIZE(rmi_i2c->supplies), |
337 | consumers: rmi_i2c->supplies); |
338 | |
339 | return 0; |
340 | } |
341 | |
342 | static int rmi_i2c_runtime_resume(struct device *dev) |
343 | { |
344 | struct i2c_client *client = to_i2c_client(dev); |
345 | struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client); |
346 | int ret; |
347 | |
348 | ret = regulator_bulk_enable(ARRAY_SIZE(rmi_i2c->supplies), |
349 | consumers: rmi_i2c->supplies); |
350 | if (ret) |
351 | return ret; |
352 | |
353 | msleep(msecs: rmi_i2c->startup_delay); |
354 | |
355 | ret = rmi_driver_resume(rmi_dev: rmi_i2c->xport.rmi_dev, clear_wake: false); |
356 | if (ret) |
357 | dev_warn(dev, "Failed to resume device: %d\n" , ret); |
358 | |
359 | return 0; |
360 | } |
361 | |
362 | static const struct dev_pm_ops rmi_i2c_pm = { |
363 | SYSTEM_SLEEP_PM_OPS(rmi_i2c_suspend, rmi_i2c_resume) |
364 | RUNTIME_PM_OPS(rmi_i2c_runtime_suspend, rmi_i2c_runtime_resume, NULL) |
365 | }; |
366 | |
367 | static const struct i2c_device_id rmi_id[] = { |
368 | { "rmi4_i2c" , 0 }, |
369 | { } |
370 | }; |
371 | MODULE_DEVICE_TABLE(i2c, rmi_id); |
372 | |
373 | static struct i2c_driver rmi_i2c_driver = { |
374 | .driver = { |
375 | .name = "rmi4_i2c" , |
376 | .pm = pm_ptr(&rmi_i2c_pm), |
377 | .of_match_table = of_match_ptr(rmi_i2c_of_match), |
378 | }, |
379 | .id_table = rmi_id, |
380 | .probe = rmi_i2c_probe, |
381 | }; |
382 | |
383 | module_i2c_driver(rmi_i2c_driver); |
384 | |
385 | MODULE_AUTHOR("Christopher Heiny <cheiny@synaptics.com>" ); |
386 | MODULE_AUTHOR("Andrew Duggan <aduggan@synaptics.com>" ); |
387 | MODULE_DESCRIPTION("RMI I2C driver" ); |
388 | MODULE_LICENSE("GPL" ); |
389 | |