1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (c) 2011-2016 Synaptics Incorporated
4 * Copyright (c) 2011 Unixphere
10 #include <linux/delay.h>
11 #include <linux/regulator/consumer.h>
12 #include "rmi_driver.h"
14 #define BUFFER_SIZE_INCREMENT 32
17 * struct rmi_i2c_xport - stores information for i2c communication
19 * @xport: The transport interface structure
20 * @client: The I2C client device structure
22 * @page_mutex: Locks current page to avoid changing pages in unexpected ways.
23 * @page: Keeps track of the current virtual page
25 * @tx_buf: Buffer used for transmitting data to the sensor over i2c.
26 * @tx_buf_size: Size of the buffer
28 * @supplies: Array of voltage regulators
29 * @startup_delay: Milliseconds to pause after powering up the regulators
31 struct rmi_i2c_xport {
32 struct rmi_transport_dev xport;
33 struct i2c_client *client;
35 struct mutex page_mutex;
41 struct regulator_bulk_data supplies[2];
45 #define RMI_PAGE_SELECT_REGISTER 0xff
46 #define RMI_I2C_PAGE(addr) (((addr) >> 8) & 0xff)
49 * rmi_set_page - Set RMI page
50 * @xport: The pointer to the rmi_transport_dev struct
51 * @page: The new page address.
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.
58 * The page_mutex lock must be held when this function is entered.
60 * Returns zero on success, non-zero on failure.
62 static int rmi_set_page(struct rmi_i2c_xport *rmi_i2c, u8 page)
64 struct i2c_client *client = rmi_i2c->client;
65 u8 txbuf[2] = {RMI_PAGE_SELECT_REGISTER, page};
68 retval = i2c_master_send(client, txbuf, sizeof(txbuf));
69 if (retval != sizeof(txbuf)) {
71 "%s: set page failed: %d.", __func__, retval);
72 return (retval < 0) ? retval : -EIO;
79 static int rmi_i2c_write_block(struct rmi_transport_dev *xport, u16 addr,
80 const void *buf, size_t len)
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;
88 mutex_lock(&rmi_i2c->page_mutex);
90 if (!rmi_i2c->tx_buf || rmi_i2c->tx_buf_size < tx_size) {
92 devm_kfree(&client->dev, rmi_i2c->tx_buf);
93 rmi_i2c->tx_buf_size = tx_size + BUFFER_SIZE_INCREMENT;
94 rmi_i2c->tx_buf = devm_kzalloc(&client->dev,
97 if (!rmi_i2c->tx_buf) {
98 rmi_i2c->tx_buf_size = 0;
104 rmi_i2c->tx_buf[0] = addr & 0xff;
105 memcpy(rmi_i2c->tx_buf + 1, buf, len);
107 if (RMI_I2C_PAGE(addr) != rmi_i2c->page) {
108 retval = rmi_set_page(rmi_i2c, RMI_I2C_PAGE(addr));
113 retval = i2c_master_send(client, rmi_i2c->tx_buf, tx_size);
114 if (retval == tx_size)
116 else if (retval >= 0)
120 rmi_dbg(RMI_DEBUG_XPORT, &client->dev,
121 "write %zd bytes at %#06x: %d (%*ph)\n",
122 len, addr, retval, (int)len, buf);
124 mutex_unlock(&rmi_i2c->page_mutex);
128 static int rmi_i2c_read_block(struct rmi_transport_dev *xport, u16 addr,
129 void *buf, size_t len)
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;
136 struct i2c_msg msgs[] = {
138 .addr = client->addr,
139 .len = sizeof(addr_offset),
143 .addr = client->addr,
150 mutex_lock(&rmi_i2c->page_mutex);
152 if (RMI_I2C_PAGE(addr) != rmi_i2c->page) {
153 retval = rmi_set_page(rmi_i2c, RMI_I2C_PAGE(addr));
158 retval = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
159 if (retval == ARRAY_SIZE(msgs))
160 retval = 0; /* success */
161 else if (retval >= 0)
165 rmi_dbg(RMI_DEBUG_XPORT, &client->dev,
166 "read %zd bytes at %#06x: %d (%*ph)\n",
167 len, addr, retval, (int)len, buf);
169 mutex_unlock(&rmi_i2c->page_mutex);
173 static const struct rmi_transport_ops rmi_i2c_ops = {
174 .write_block = rmi_i2c_write_block,
175 .read_block = rmi_i2c_read_block,
179 static const struct of_device_id rmi_i2c_of_match[] = {
180 { .compatible = "syna,rmi4-i2c" },
183 MODULE_DEVICE_TABLE(of, rmi_i2c_of_match);
186 static void rmi_i2c_regulator_bulk_disable(void *data)
188 struct rmi_i2c_xport *rmi_i2c = data;
190 regulator_bulk_disable(ARRAY_SIZE(rmi_i2c->supplies),
194 static void rmi_i2c_unregister_transport(void *data)
196 struct rmi_i2c_xport *rmi_i2c = data;
198 rmi_unregister_transport_device(&rmi_i2c->xport);
201 static int rmi_i2c_probe(struct i2c_client *client)
203 struct rmi_device_platform_data *pdata;
204 struct rmi_device_platform_data *client_pdata =
205 dev_get_platdata(&client->dev);
206 struct rmi_i2c_xport *rmi_i2c;
209 rmi_i2c = devm_kzalloc(&client->dev, sizeof(struct rmi_i2c_xport),
214 pdata = &rmi_i2c->xport.pdata;
216 if (!client->dev.of_node && client_pdata)
217 *pdata = *client_pdata;
219 pdata->irq = client->irq;
221 rmi_dbg(RMI_DEBUG_XPORT, &client->dev, "Probing %s.\n",
222 dev_name(&client->dev));
224 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
225 dev_err(&client->dev,
226 "adapter does not support required functionality\n");
230 rmi_i2c->supplies[0].supply = "vdd";
231 rmi_i2c->supplies[1].supply = "vio";
232 error = devm_regulator_bulk_get(&client->dev,
233 ARRAY_SIZE(rmi_i2c->supplies),
238 error = regulator_bulk_enable(ARRAY_SIZE(rmi_i2c->supplies),
243 error = devm_add_action_or_reset(&client->dev,
244 rmi_i2c_regulator_bulk_disable,
249 of_property_read_u32(client->dev.of_node, "syna,startup-delay-ms",
250 &rmi_i2c->startup_delay);
252 msleep(rmi_i2c->startup_delay);
254 rmi_i2c->client = client;
255 mutex_init(&rmi_i2c->page_mutex);
257 rmi_i2c->xport.dev = &client->dev;
258 rmi_i2c->xport.proto_name = "i2c";
259 rmi_i2c->xport.ops = &rmi_i2c_ops;
261 i2c_set_clientdata(client, rmi_i2c);
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.
267 error = rmi_set_page(rmi_i2c, 0);
269 dev_err(&client->dev, "Failed to set page select to 0\n");
273 dev_info(&client->dev, "registering I2C-connected sensor\n");
275 error = rmi_register_transport_device(&rmi_i2c->xport);
277 dev_err(&client->dev, "failed to register sensor: %d\n", error);
281 error = devm_add_action_or_reset(&client->dev,
282 rmi_i2c_unregister_transport,
290 static int rmi_i2c_suspend(struct device *dev)
292 struct i2c_client *client = to_i2c_client(dev);
293 struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client);
296 ret = rmi_driver_suspend(rmi_i2c->xport.rmi_dev, true);
298 dev_warn(dev, "Failed to resume device: %d\n", ret);
300 regulator_bulk_disable(ARRAY_SIZE(rmi_i2c->supplies),
306 static int rmi_i2c_resume(struct device *dev)
308 struct i2c_client *client = to_i2c_client(dev);
309 struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client);
312 ret = regulator_bulk_enable(ARRAY_SIZE(rmi_i2c->supplies),
317 msleep(rmi_i2c->startup_delay);
319 ret = rmi_driver_resume(rmi_i2c->xport.rmi_dev, true);
321 dev_warn(dev, "Failed to resume device: %d\n", ret);
326 static int rmi_i2c_runtime_suspend(struct device *dev)
328 struct i2c_client *client = to_i2c_client(dev);
329 struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client);
332 ret = rmi_driver_suspend(rmi_i2c->xport.rmi_dev, false);
334 dev_warn(dev, "Failed to resume device: %d\n", ret);
336 regulator_bulk_disable(ARRAY_SIZE(rmi_i2c->supplies),
342 static int rmi_i2c_runtime_resume(struct device *dev)
344 struct i2c_client *client = to_i2c_client(dev);
345 struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client);
348 ret = regulator_bulk_enable(ARRAY_SIZE(rmi_i2c->supplies),
353 msleep(rmi_i2c->startup_delay);
355 ret = rmi_driver_resume(rmi_i2c->xport.rmi_dev, false);
357 dev_warn(dev, "Failed to resume device: %d\n", ret);
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)
367 static const struct i2c_device_id rmi_id[] = {
371 MODULE_DEVICE_TABLE(i2c, rmi_id);
373 static struct i2c_driver rmi_i2c_driver = {
376 .pm = pm_ptr(&rmi_i2c_pm),
377 .of_match_table = of_match_ptr(rmi_i2c_of_match),
380 .probe_new = rmi_i2c_probe,
383 module_i2c_driver(rmi_i2c_driver);
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");