blob: 02a7bacdc056b8ebfc20fb10bbfa18ecf94e557d [file] [log] [blame]
Simon Glass89969002013-02-25 14:08:38 -08001/*
2 * ChromeOS EC multi-function device (I2C)
3 *
4 * Copyright (C) 2012 Google, Inc
5 *
6 * This software is licensed under the terms of the GNU General Public
7 * License version 2, as published by the Free Software Foundation, and
8 * may be copied, distributed, and modified under those terms.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 */
15
Wei-Ning Huangabeed712018-04-18 12:24:03 +020016#include <linux/acpi.h>
Stephen Barberd3654072015-06-09 13:04:46 +020017#include <linux/delay.h>
Simon Glass89969002013-02-25 14:08:38 -080018#include <linux/kernel.h>
19#include <linux/module.h>
20#include <linux/i2c.h>
21#include <linux/interrupt.h>
22#include <linux/mfd/cros_ec.h>
23#include <linux/mfd/cros_ec_commands.h>
24#include <linux/platform_device.h>
25#include <linux/slab.h>
26
Stephen Barberd3654072015-06-09 13:04:46 +020027/**
28 * Request format for protocol v3
29 * byte 0 0xda (EC_COMMAND_PROTOCOL_3)
30 * byte 1-8 struct ec_host_request
31 * byte 10- response data
32 */
33struct ec_host_request_i2c {
34 /* Always 0xda to backward compatible with v2 struct */
35 uint8_t command_protocol;
36 struct ec_host_request ec_request;
37} __packed;
38
39
40/*
41 * Response format for protocol v3
42 * byte 0 result code
43 * byte 1 packet_length
44 * byte 2-9 struct ec_host_response
45 * byte 10- response data
46 */
47struct ec_host_response_i2c {
48 uint8_t result;
49 uint8_t packet_length;
50 struct ec_host_response ec_response;
51} __packed;
52
Simon Glass89969002013-02-25 14:08:38 -080053static inline struct cros_ec_device *to_ec_dev(struct device *dev)
54{
55 struct i2c_client *client = to_i2c_client(dev);
56
57 return i2c_get_clientdata(client);
58}
59
Stephen Barberd3654072015-06-09 13:04:46 +020060static int cros_ec_pkt_xfer_i2c(struct cros_ec_device *ec_dev,
61 struct cros_ec_command *msg)
62{
63 struct i2c_client *client = ec_dev->priv;
64 int ret = -ENOMEM;
65 int i;
66 int packet_len;
67 u8 *out_buf = NULL;
68 u8 *in_buf = NULL;
69 u8 sum;
70 struct i2c_msg i2c_msg[2];
71 struct ec_host_response *ec_response;
72 struct ec_host_request_i2c *ec_request_i2c;
73 struct ec_host_response_i2c *ec_response_i2c;
74 int request_header_size = sizeof(struct ec_host_request_i2c);
75 int response_header_size = sizeof(struct ec_host_response_i2c);
76
77 i2c_msg[0].addr = client->addr;
78 i2c_msg[0].flags = 0;
79 i2c_msg[1].addr = client->addr;
80 i2c_msg[1].flags = I2C_M_RD;
81
82 packet_len = msg->insize + response_header_size;
83 BUG_ON(packet_len > ec_dev->din_size);
84 in_buf = ec_dev->din;
85 i2c_msg[1].len = packet_len;
86 i2c_msg[1].buf = (char *) in_buf;
87
88 packet_len = msg->outsize + request_header_size;
89 BUG_ON(packet_len > ec_dev->dout_size);
90 out_buf = ec_dev->dout;
91 i2c_msg[0].len = packet_len;
92 i2c_msg[0].buf = (char *) out_buf;
93
94 /* create request data */
95 ec_request_i2c = (struct ec_host_request_i2c *) out_buf;
96 ec_request_i2c->command_protocol = EC_COMMAND_PROTOCOL_3;
97
98 ec_dev->dout++;
99 ret = cros_ec_prepare_tx(ec_dev, msg);
100 ec_dev->dout--;
101
102 /* send command to EC and read answer */
103 ret = i2c_transfer(client->adapter, i2c_msg, 2);
104 if (ret < 0) {
105 dev_dbg(ec_dev->dev, "i2c transfer failed: %d\n", ret);
106 goto done;
107 } else if (ret != 2) {
108 dev_err(ec_dev->dev, "failed to get response: %d\n", ret);
109 ret = -EIO;
110 goto done;
111 }
112
113 ec_response_i2c = (struct ec_host_response_i2c *) in_buf;
114 msg->result = ec_response_i2c->result;
115 ec_response = &ec_response_i2c->ec_response;
116
117 switch (msg->result) {
118 case EC_RES_SUCCESS:
119 break;
120 case EC_RES_IN_PROGRESS:
121 ret = -EAGAIN;
122 dev_dbg(ec_dev->dev, "command 0x%02x in progress\n",
123 msg->command);
124 goto done;
125
126 default:
127 dev_dbg(ec_dev->dev, "command 0x%02x returned %d\n",
128 msg->command, msg->result);
129 /*
130 * When we send v3 request to v2 ec, ec won't recognize the
131 * 0xda (EC_COMMAND_PROTOCOL_3) and will return with status
132 * EC_RES_INVALID_COMMAND with zero data length.
133 *
134 * In case of invalid command for v3 protocol the data length
135 * will be at least sizeof(struct ec_host_response)
136 */
137 if (ec_response_i2c->result == EC_RES_INVALID_COMMAND &&
138 ec_response_i2c->packet_length == 0) {
139 ret = -EPROTONOSUPPORT;
140 goto done;
141 }
142 }
143
144 if (ec_response_i2c->packet_length < sizeof(struct ec_host_response)) {
145 dev_err(ec_dev->dev,
146 "response of %u bytes too short; not a full header\n",
147 ec_response_i2c->packet_length);
148 ret = -EBADMSG;
149 goto done;
150 }
151
152 if (msg->insize < ec_response->data_len) {
153 dev_err(ec_dev->dev,
154 "response data size is too large: expected %u, got %u\n",
155 msg->insize,
156 ec_response->data_len);
157 ret = -EMSGSIZE;
158 goto done;
159 }
160
161 /* copy response packet payload and compute checksum */
162 sum = 0;
163 for (i = 0; i < sizeof(struct ec_host_response); i++)
164 sum += ((u8 *)ec_response)[i];
165
166 memcpy(msg->data,
167 in_buf + response_header_size,
168 ec_response->data_len);
169 for (i = 0; i < ec_response->data_len; i++)
170 sum += msg->data[i];
171
172 /* All bytes should sum to zero */
173 if (sum) {
174 dev_err(ec_dev->dev, "bad packet checksum\n");
175 ret = -EBADMSG;
176 goto done;
177 }
178
179 ret = ec_response->data_len;
180
181done:
182 if (msg->command == EC_CMD_REBOOT_EC)
183 msleep(EC_REBOOT_DELAY_MS);
184
185 return ret;
186}
187
Bill Richardson7e6cb5b2014-06-18 11:14:00 -0700188static int cros_ec_cmd_xfer_i2c(struct cros_ec_device *ec_dev,
Bill Richardson5d4773e2014-06-18 11:14:02 -0700189 struct cros_ec_command *msg)
Simon Glass89969002013-02-25 14:08:38 -0800190{
191 struct i2c_client *client = ec_dev->priv;
192 int ret = -ENOMEM;
193 int i;
Doug Andersond6c15ed2014-06-27 12:56:12 -0700194 int len;
Simon Glass89969002013-02-25 14:08:38 -0800195 int packet_len;
196 u8 *out_buf = NULL;
197 u8 *in_buf = NULL;
198 u8 sum;
199 struct i2c_msg i2c_msg[2];
200
201 i2c_msg[0].addr = client->addr;
202 i2c_msg[0].flags = 0;
203 i2c_msg[1].addr = client->addr;
204 i2c_msg[1].flags = I2C_M_RD;
205
206 /*
207 * allocate larger packet (one byte for checksum, one byte for
208 * length, and one for result code)
209 */
Bill Richardson5d4773e2014-06-18 11:14:02 -0700210 packet_len = msg->insize + 3;
Simon Glass89969002013-02-25 14:08:38 -0800211 in_buf = kzalloc(packet_len, GFP_KERNEL);
212 if (!in_buf)
213 goto done;
214 i2c_msg[1].len = packet_len;
215 i2c_msg[1].buf = (char *)in_buf;
216
217 /*
218 * allocate larger packet (one byte for checksum, one for
219 * command code, one for length, and one for command version)
220 */
Bill Richardson5d4773e2014-06-18 11:14:02 -0700221 packet_len = msg->outsize + 4;
Simon Glass89969002013-02-25 14:08:38 -0800222 out_buf = kzalloc(packet_len, GFP_KERNEL);
223 if (!out_buf)
224 goto done;
225 i2c_msg[0].len = packet_len;
226 i2c_msg[0].buf = (char *)out_buf;
227
228 out_buf[0] = EC_CMD_VERSION0 + msg->version;
Bill Richardson5d4773e2014-06-18 11:14:02 -0700229 out_buf[1] = msg->command;
230 out_buf[2] = msg->outsize;
Simon Glass89969002013-02-25 14:08:38 -0800231
232 /* copy message payload and compute checksum */
233 sum = out_buf[0] + out_buf[1] + out_buf[2];
Bill Richardson5d4773e2014-06-18 11:14:02 -0700234 for (i = 0; i < msg->outsize; i++) {
Javier Martinez Canillasa8411782015-06-09 13:04:42 +0200235 out_buf[3 + i] = msg->data[i];
Simon Glass89969002013-02-25 14:08:38 -0800236 sum += out_buf[3 + i];
237 }
Bill Richardson5d4773e2014-06-18 11:14:02 -0700238 out_buf[3 + msg->outsize] = sum;
Simon Glass89969002013-02-25 14:08:38 -0800239
240 /* send command to EC and read answer */
241 ret = i2c_transfer(client->adapter, i2c_msg, 2);
242 if (ret < 0) {
243 dev_err(ec_dev->dev, "i2c transfer failed: %d\n", ret);
244 goto done;
245 } else if (ret != 2) {
246 dev_err(ec_dev->dev, "failed to get response: %d\n", ret);
247 ret = -EIO;
248 goto done;
249 }
250
251 /* check response error code */
Bill Richardson6db07b62014-06-18 11:14:05 -0700252 msg->result = i2c_msg[1].buf[0];
253 ret = cros_ec_check_result(ec_dev, msg);
254 if (ret)
Simon Glass89969002013-02-25 14:08:38 -0800255 goto done;
Simon Glass89969002013-02-25 14:08:38 -0800256
Doug Andersond6c15ed2014-06-27 12:56:12 -0700257 len = in_buf[1];
258 if (len > msg->insize) {
259 dev_err(ec_dev->dev, "packet too long (%d bytes, expected %d)",
260 len, msg->insize);
261 ret = -ENOSPC;
262 goto done;
263 }
264
Simon Glass89969002013-02-25 14:08:38 -0800265 /* copy response packet payload and compute checksum */
266 sum = in_buf[0] + in_buf[1];
Doug Andersond6c15ed2014-06-27 12:56:12 -0700267 for (i = 0; i < len; i++) {
Javier Martinez Canillasa8411782015-06-09 13:04:42 +0200268 msg->data[i] = in_buf[2 + i];
Simon Glass89969002013-02-25 14:08:38 -0800269 sum += in_buf[2 + i];
270 }
271 dev_dbg(ec_dev->dev, "packet: %*ph, sum = %02x\n",
272 i2c_msg[1].len, in_buf, sum);
Doug Andersond6c15ed2014-06-27 12:56:12 -0700273 if (sum != in_buf[2 + len]) {
Simon Glass89969002013-02-25 14:08:38 -0800274 dev_err(ec_dev->dev, "bad packet checksum\n");
275 ret = -EBADMSG;
276 goto done;
277 }
278
Doug Andersond6c15ed2014-06-27 12:56:12 -0700279 ret = len;
Stephen Barberd3654072015-06-09 13:04:46 +0200280done:
Simon Glass89969002013-02-25 14:08:38 -0800281 kfree(in_buf);
282 kfree(out_buf);
Stephen Barberd3654072015-06-09 13:04:46 +0200283 if (msg->command == EC_CMD_REBOOT_EC)
284 msleep(EC_REBOOT_DELAY_MS);
285
Simon Glass89969002013-02-25 14:08:38 -0800286 return ret;
287}
288
Thierry Reding192afe52013-11-25 13:22:31 +0100289static int cros_ec_i2c_probe(struct i2c_client *client,
Simon Glass89969002013-02-25 14:08:38 -0800290 const struct i2c_device_id *dev_id)
291{
292 struct device *dev = &client->dev;
293 struct cros_ec_device *ec_dev = NULL;
294 int err;
295
Lee Jones2756db62015-10-28 16:02:48 +0000296 ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL);
Simon Glass89969002013-02-25 14:08:38 -0800297 if (!ec_dev)
298 return -ENOMEM;
299
300 i2c_set_clientdata(client, ec_dev);
Simon Glass89969002013-02-25 14:08:38 -0800301 ec_dev->dev = dev;
302 ec_dev->priv = client;
303 ec_dev->irq = client->irq;
Bill Richardson7e6cb5b2014-06-18 11:14:00 -0700304 ec_dev->cmd_xfer = cros_ec_cmd_xfer_i2c;
Stephen Barberd3654072015-06-09 13:04:46 +0200305 ec_dev->pkt_xfer = cros_ec_pkt_xfer_i2c;
Simon Glass89969002013-02-25 14:08:38 -0800306 ec_dev->phys_name = client->adapter->name;
Stephen Barberd3654072015-06-09 13:04:46 +0200307 ec_dev->din_size = sizeof(struct ec_host_response_i2c) +
Stephen Barber2c7589a2015-06-09 13:04:45 +0200308 sizeof(struct ec_response_get_protocol_info);
Stephen Barberd3654072015-06-09 13:04:46 +0200309 ec_dev->dout_size = sizeof(struct ec_host_request_i2c);
Simon Glass89969002013-02-25 14:08:38 -0800310
311 err = cros_ec_register(ec_dev);
312 if (err) {
313 dev_err(dev, "cannot register EC\n");
314 return err;
315 }
316
317 return 0;
318}
319
Thierry Reding192afe52013-11-25 13:22:31 +0100320static int cros_ec_i2c_remove(struct i2c_client *client)
Simon Glass89969002013-02-25 14:08:38 -0800321{
322 struct cros_ec_device *ec_dev = i2c_get_clientdata(client);
323
324 cros_ec_remove(ec_dev);
325
326 return 0;
327}
328
329#ifdef CONFIG_PM_SLEEP
330static int cros_ec_i2c_suspend(struct device *dev)
331{
332 struct cros_ec_device *ec_dev = to_ec_dev(dev);
333
334 return cros_ec_suspend(ec_dev);
335}
336
337static int cros_ec_i2c_resume(struct device *dev)
338{
339 struct cros_ec_device *ec_dev = to_ec_dev(dev);
340
341 return cros_ec_resume(ec_dev);
342}
343#endif
344
345static SIMPLE_DEV_PM_OPS(cros_ec_i2c_pm_ops, cros_ec_i2c_suspend,
346 cros_ec_i2c_resume);
347
Wei-Ning Huangabeed712018-04-18 12:24:03 +0200348#ifdef CONFIG_OF
Javier Martinez Canillas385c0012015-08-25 07:48:10 +0200349static const struct of_device_id cros_ec_i2c_of_match[] = {
350 { .compatible = "google,cros-ec-i2c", },
351 { /* sentinel */ },
352};
353MODULE_DEVICE_TABLE(of, cros_ec_i2c_of_match);
Wei-Ning Huangabeed712018-04-18 12:24:03 +0200354#endif
Javier Martinez Canillas385c0012015-08-25 07:48:10 +0200355
Simon Glass89969002013-02-25 14:08:38 -0800356static const struct i2c_device_id cros_ec_i2c_id[] = {
357 { "cros-ec-i2c", 0 },
358 { }
359};
360MODULE_DEVICE_TABLE(i2c, cros_ec_i2c_id);
361
Wei-Ning Huangabeed712018-04-18 12:24:03 +0200362#ifdef CONFIG_ACPI
363static const struct acpi_device_id cros_ec_i2c_acpi_id[] = {
364 { "GOOG0008", 0 },
365 { /* sentinel */ }
366};
367MODULE_DEVICE_TABLE(acpi, cros_ec_i2c_acpi_id);
368#endif
369
Simon Glass89969002013-02-25 14:08:38 -0800370static struct i2c_driver cros_ec_driver = {
371 .driver = {
372 .name = "cros-ec-i2c",
Wei-Ning Huangabeed712018-04-18 12:24:03 +0200373 .acpi_match_table = ACPI_PTR(cros_ec_i2c_acpi_id),
Javier Martinez Canillas385c0012015-08-25 07:48:10 +0200374 .of_match_table = of_match_ptr(cros_ec_i2c_of_match),
Simon Glass89969002013-02-25 14:08:38 -0800375 .pm = &cros_ec_i2c_pm_ops,
376 },
Thierry Reding192afe52013-11-25 13:22:31 +0100377 .probe = cros_ec_i2c_probe,
378 .remove = cros_ec_i2c_remove,
Simon Glass89969002013-02-25 14:08:38 -0800379 .id_table = cros_ec_i2c_id,
380};
381
382module_i2c_driver(cros_ec_driver);
383
384MODULE_LICENSE("GPL");
385MODULE_DESCRIPTION("ChromeOS EC multi function device");