Loading...
Note: File does not exist in v3.1.
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * cros_ec_dev - expose the Chrome OS Embedded Controller to user-space
4 *
5 * Copyright (C) 2014 Google, Inc.
6 */
7
8#include <linux/dmi.h>
9#include <linux/kconfig.h>
10#include <linux/mfd/core.h>
11#include <linux/module.h>
12#include <linux/mod_devicetable.h>
13#include <linux/of.h>
14#include <linux/platform_device.h>
15#include <linux/platform_data/cros_ec_chardev.h>
16#include <linux/platform_data/cros_ec_commands.h>
17#include <linux/platform_data/cros_ec_proto.h>
18#include <linux/slab.h>
19
20#define DRV_NAME "cros-ec-dev"
21
22static struct class cros_class = {
23 .name = "chromeos",
24};
25
26/**
27 * struct cros_feature_to_name - CrOS feature id to name/short description.
28 * @id: The feature identifier.
29 * @name: Device name associated with the feature id.
30 * @desc: Short name that will be displayed.
31 */
32struct cros_feature_to_name {
33 unsigned int id;
34 const char *name;
35 const char *desc;
36};
37
38/**
39 * struct cros_feature_to_cells - CrOS feature id to mfd cells association.
40 * @id: The feature identifier.
41 * @mfd_cells: Pointer to the array of mfd cells that needs to be added.
42 * @num_cells: Number of mfd cells into the array.
43 */
44struct cros_feature_to_cells {
45 unsigned int id;
46 const struct mfd_cell *mfd_cells;
47 unsigned int num_cells;
48};
49
50static const struct cros_feature_to_name cros_mcu_devices[] = {
51 {
52 .id = EC_FEATURE_FINGERPRINT,
53 .name = CROS_EC_DEV_FP_NAME,
54 .desc = "Fingerprint",
55 },
56 {
57 .id = EC_FEATURE_ISH,
58 .name = CROS_EC_DEV_ISH_NAME,
59 .desc = "Integrated Sensor Hub",
60 },
61 {
62 .id = EC_FEATURE_SCP,
63 .name = CROS_EC_DEV_SCP_NAME,
64 .desc = "System Control Processor",
65 },
66 {
67 .id = EC_FEATURE_TOUCHPAD,
68 .name = CROS_EC_DEV_TP_NAME,
69 .desc = "Touchpad",
70 },
71};
72
73static const struct mfd_cell cros_ec_cec_cells[] = {
74 { .name = "cros-ec-cec", },
75};
76
77static const struct mfd_cell cros_ec_gpio_cells[] = {
78 { .name = "cros-ec-gpio", },
79};
80
81static const struct mfd_cell cros_ec_rtc_cells[] = {
82 { .name = "cros-ec-rtc", },
83};
84
85static const struct mfd_cell cros_ec_sensorhub_cells[] = {
86 { .name = "cros-ec-sensorhub", },
87};
88
89static const struct mfd_cell cros_usbpd_charger_cells[] = {
90 { .name = "cros-usbpd-charger", },
91 { .name = "cros-usbpd-logger", },
92};
93
94static const struct mfd_cell cros_usbpd_notify_cells[] = {
95 { .name = "cros-usbpd-notify", },
96};
97
98static const struct mfd_cell cros_ec_wdt_cells[] = {
99 { .name = "cros-ec-wdt", }
100};
101
102static const struct cros_feature_to_cells cros_subdevices[] = {
103 {
104 .id = EC_FEATURE_CEC,
105 .mfd_cells = cros_ec_cec_cells,
106 .num_cells = ARRAY_SIZE(cros_ec_cec_cells),
107 },
108 {
109 .id = EC_FEATURE_GPIO,
110 .mfd_cells = cros_ec_gpio_cells,
111 .num_cells = ARRAY_SIZE(cros_ec_gpio_cells),
112 },
113 {
114 .id = EC_FEATURE_RTC,
115 .mfd_cells = cros_ec_rtc_cells,
116 .num_cells = ARRAY_SIZE(cros_ec_rtc_cells),
117 },
118 {
119 .id = EC_FEATURE_USB_PD,
120 .mfd_cells = cros_usbpd_charger_cells,
121 .num_cells = ARRAY_SIZE(cros_usbpd_charger_cells),
122 },
123 {
124 .id = EC_FEATURE_HANG_DETECT,
125 .mfd_cells = cros_ec_wdt_cells,
126 .num_cells = ARRAY_SIZE(cros_ec_wdt_cells),
127 },
128};
129
130static const struct mfd_cell cros_ec_platform_cells[] = {
131 { .name = "cros-ec-chardev", },
132 { .name = "cros-ec-debugfs", },
133 { .name = "cros-ec-sysfs", },
134};
135
136static const struct mfd_cell cros_ec_pchg_cells[] = {
137 { .name = "cros-ec-pchg", },
138};
139
140static const struct mfd_cell cros_ec_lightbar_cells[] = {
141 { .name = "cros-ec-lightbar", }
142};
143
144static const struct mfd_cell cros_ec_vbc_cells[] = {
145 { .name = "cros-ec-vbc", }
146};
147
148static void cros_ec_class_release(struct device *dev)
149{
150 kfree(to_cros_ec_dev(dev));
151}
152
153static int ec_device_probe(struct platform_device *pdev)
154{
155 int retval = -ENOMEM;
156 struct device_node *node;
157 struct device *dev = &pdev->dev;
158 struct cros_ec_platform *ec_platform = dev_get_platdata(dev);
159 struct cros_ec_dev *ec = kzalloc(sizeof(*ec), GFP_KERNEL);
160 struct ec_response_pchg_count pchg_count;
161 int i;
162
163 if (!ec)
164 return retval;
165
166 dev_set_drvdata(dev, ec);
167 ec->ec_dev = dev_get_drvdata(dev->parent);
168 ec->dev = dev;
169 ec->cmd_offset = ec_platform->cmd_offset;
170 ec->features.flags[0] = -1U; /* Not cached yet */
171 ec->features.flags[1] = -1U; /* Not cached yet */
172 device_initialize(&ec->class_dev);
173
174 for (i = 0; i < ARRAY_SIZE(cros_mcu_devices); i++) {
175 /*
176 * Check whether this is actually a dedicated MCU rather
177 * than an standard EC.
178 */
179 if (cros_ec_check_features(ec, cros_mcu_devices[i].id)) {
180 dev_info(dev, "CrOS %s MCU detected\n",
181 cros_mcu_devices[i].desc);
182 /*
183 * Help userspace differentiating ECs from other MCU,
184 * regardless of the probing order.
185 */
186 ec_platform->ec_name = cros_mcu_devices[i].name;
187 break;
188 }
189 }
190
191 /*
192 * Add the class device
193 */
194 ec->class_dev.class = &cros_class;
195 ec->class_dev.parent = dev;
196 ec->class_dev.release = cros_ec_class_release;
197
198 retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name);
199 if (retval) {
200 dev_err(dev, "dev_set_name failed => %d\n", retval);
201 goto failed;
202 }
203
204 retval = device_add(&ec->class_dev);
205 if (retval)
206 goto failed;
207
208 /* check whether this EC is a sensor hub. */
209 if (cros_ec_get_sensor_count(ec) > 0) {
210 retval = mfd_add_hotplug_devices(ec->dev,
211 cros_ec_sensorhub_cells,
212 ARRAY_SIZE(cros_ec_sensorhub_cells));
213 if (retval)
214 dev_err(ec->dev, "failed to add %s subdevice: %d\n",
215 cros_ec_sensorhub_cells->name, retval);
216 }
217
218 /*
219 * The following subdevices can be detected by sending the
220 * EC_FEATURE_GET_CMD Embedded Controller device.
221 */
222 for (i = 0; i < ARRAY_SIZE(cros_subdevices); i++) {
223 if (cros_ec_check_features(ec, cros_subdevices[i].id)) {
224 retval = mfd_add_hotplug_devices(ec->dev,
225 cros_subdevices[i].mfd_cells,
226 cros_subdevices[i].num_cells);
227 if (retval)
228 dev_err(ec->dev,
229 "failed to add %s subdevice: %d\n",
230 cros_subdevices[i].mfd_cells->name,
231 retval);
232 }
233 }
234
235 /*
236 * Lightbar is a special case. Newer devices support autodetection,
237 * but older ones do not.
238 */
239 if (cros_ec_check_features(ec, EC_FEATURE_LIGHTBAR) ||
240 dmi_match(DMI_PRODUCT_NAME, "Link")) {
241 retval = mfd_add_hotplug_devices(ec->dev,
242 cros_ec_lightbar_cells,
243 ARRAY_SIZE(cros_ec_lightbar_cells));
244 if (retval)
245 dev_warn(ec->dev, "failed to add lightbar: %d\n",
246 retval);
247 }
248
249 /*
250 * The PD notifier driver cell is separate since it only needs to be
251 * explicitly added on platforms that don't have the PD notifier ACPI
252 * device entry defined.
253 */
254 if (IS_ENABLED(CONFIG_OF) && ec->ec_dev->dev->of_node) {
255 if (cros_ec_check_features(ec, EC_FEATURE_USB_PD)) {
256 retval = mfd_add_hotplug_devices(ec->dev,
257 cros_usbpd_notify_cells,
258 ARRAY_SIZE(cros_usbpd_notify_cells));
259 if (retval)
260 dev_err(ec->dev,
261 "failed to add PD notify devices: %d\n",
262 retval);
263 }
264 }
265
266 /*
267 * The PCHG device cannot be detected by sending EC_FEATURE_GET_CMD, but
268 * it can be detected by querying the number of peripheral chargers.
269 */
270 retval = cros_ec_cmd(ec->ec_dev, 0, EC_CMD_PCHG_COUNT, NULL, 0,
271 &pchg_count, sizeof(pchg_count));
272 if (retval >= 0 && pchg_count.port_count) {
273 retval = mfd_add_hotplug_devices(ec->dev,
274 cros_ec_pchg_cells,
275 ARRAY_SIZE(cros_ec_pchg_cells));
276 if (retval)
277 dev_warn(ec->dev, "failed to add pchg: %d\n",
278 retval);
279 }
280
281 /*
282 * The following subdevices cannot be detected by sending the
283 * EC_FEATURE_GET_CMD to the Embedded Controller device.
284 */
285 retval = mfd_add_hotplug_devices(ec->dev, cros_ec_platform_cells,
286 ARRAY_SIZE(cros_ec_platform_cells));
287 if (retval)
288 dev_warn(ec->dev,
289 "failed to add cros-ec platform devices: %d\n",
290 retval);
291
292 /* Check whether this EC instance has a VBC NVRAM */
293 node = ec->ec_dev->dev->of_node;
294 if (of_property_read_bool(node, "google,has-vbc-nvram")) {
295 retval = mfd_add_hotplug_devices(ec->dev, cros_ec_vbc_cells,
296 ARRAY_SIZE(cros_ec_vbc_cells));
297 if (retval)
298 dev_warn(ec->dev, "failed to add VBC devices: %d\n",
299 retval);
300 }
301
302 return 0;
303
304failed:
305 put_device(&ec->class_dev);
306 return retval;
307}
308
309static void ec_device_remove(struct platform_device *pdev)
310{
311 struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);
312
313 mfd_remove_devices(ec->dev);
314 device_unregister(&ec->class_dev);
315}
316
317static const struct platform_device_id cros_ec_id[] = {
318 { DRV_NAME, 0 },
319 { /* sentinel */ }
320};
321MODULE_DEVICE_TABLE(platform, cros_ec_id);
322
323static struct platform_driver cros_ec_dev_driver = {
324 .driver = {
325 .name = DRV_NAME,
326 },
327 .id_table = cros_ec_id,
328 .probe = ec_device_probe,
329 .remove_new = ec_device_remove,
330};
331
332static int __init cros_ec_dev_init(void)
333{
334 int ret;
335
336 ret = class_register(&cros_class);
337 if (ret) {
338 pr_err(CROS_EC_DEV_NAME ": failed to register device class\n");
339 return ret;
340 }
341
342 /* Register the driver */
343 ret = platform_driver_register(&cros_ec_dev_driver);
344 if (ret < 0) {
345 pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret);
346 goto failed_devreg;
347 }
348 return 0;
349
350failed_devreg:
351 class_unregister(&cros_class);
352 return ret;
353}
354
355static void __exit cros_ec_dev_exit(void)
356{
357 platform_driver_unregister(&cros_ec_dev_driver);
358 class_unregister(&cros_class);
359}
360
361module_init(cros_ec_dev_init);
362module_exit(cros_ec_dev_exit);
363
364MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>");
365MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller");
366MODULE_VERSION("1.0");
367MODULE_LICENSE("GPL");