1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * ChromeOS Embedded Controller
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
22 static 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 */
32 struct 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 */
44 struct cros_feature_to_cells {
45 unsigned int id;
46 const struct mfd_cell *mfd_cells;
47 unsigned int num_cells;
48 };
49
50 static 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
73 static const struct mfd_cell cros_ec_cec_cells[] = {
74 { .name = "cros-ec-cec", },
75 };
76
77 static const struct mfd_cell cros_ec_gpio_cells[] = {
78 { .name = "cros-ec-gpio", },
79 };
80
81 static const struct mfd_cell cros_ec_rtc_cells[] = {
82 { .name = "cros-ec-rtc", },
83 };
84
85 static const struct mfd_cell cros_ec_sensorhub_cells[] = {
86 { .name = "cros-ec-sensorhub", },
87 };
88
89 static const struct mfd_cell cros_usbpd_charger_cells[] = {
90 { .name = "cros-charge-control", },
91 { .name = "cros-usbpd-charger", },
92 { .name = "cros-usbpd-logger", },
93 };
94
95 static const struct mfd_cell cros_usbpd_notify_cells[] = {
96 { .name = "cros-usbpd-notify", },
97 };
98
99 static const struct mfd_cell cros_ec_wdt_cells[] = {
100 { .name = "cros-ec-wdt", }
101 };
102
103 static const struct mfd_cell cros_ec_led_cells[] = {
104 { .name = "cros-ec-led", },
105 };
106
107 static const struct mfd_cell cros_ec_keyboard_leds_cells[] = {
108 { .name = "cros-keyboard-leds", },
109 };
110
111 static const struct cros_feature_to_cells cros_subdevices[] = {
112 {
113 .id = EC_FEATURE_CEC,
114 .mfd_cells = cros_ec_cec_cells,
115 .num_cells = ARRAY_SIZE(cros_ec_cec_cells),
116 },
117 {
118 .id = EC_FEATURE_GPIO,
119 .mfd_cells = cros_ec_gpio_cells,
120 .num_cells = ARRAY_SIZE(cros_ec_gpio_cells),
121 },
122 {
123 .id = EC_FEATURE_RTC,
124 .mfd_cells = cros_ec_rtc_cells,
125 .num_cells = ARRAY_SIZE(cros_ec_rtc_cells),
126 },
127 {
128 .id = EC_FEATURE_USB_PD,
129 .mfd_cells = cros_usbpd_charger_cells,
130 .num_cells = ARRAY_SIZE(cros_usbpd_charger_cells),
131 },
132 {
133 .id = EC_FEATURE_HANG_DETECT,
134 .mfd_cells = cros_ec_wdt_cells,
135 .num_cells = ARRAY_SIZE(cros_ec_wdt_cells),
136 },
137 {
138 .id = EC_FEATURE_LED,
139 .mfd_cells = cros_ec_led_cells,
140 .num_cells = ARRAY_SIZE(cros_ec_led_cells),
141 },
142 {
143 .id = EC_FEATURE_PWM_KEYB,
144 .mfd_cells = cros_ec_keyboard_leds_cells,
145 .num_cells = ARRAY_SIZE(cros_ec_keyboard_leds_cells),
146 },
147 };
148
149 static const struct mfd_cell cros_ec_platform_cells[] = {
150 { .name = "cros-ec-chardev", },
151 { .name = "cros-ec-debugfs", },
152 { .name = "cros-ec-hwmon", },
153 { .name = "cros-ec-sysfs", },
154 };
155
156 static const struct mfd_cell cros_ec_pchg_cells[] = {
157 { .name = "cros-ec-pchg", },
158 };
159
160 static const struct mfd_cell cros_ec_lightbar_cells[] = {
161 { .name = "cros-ec-lightbar", }
162 };
163
164 static const struct mfd_cell cros_ec_vbc_cells[] = {
165 { .name = "cros-ec-vbc", }
166 };
167
cros_ec_class_release(struct device * dev)168 static void cros_ec_class_release(struct device *dev)
169 {
170 kfree(to_cros_ec_dev(dev));
171 }
172
ec_device_probe(struct platform_device * pdev)173 static int ec_device_probe(struct platform_device *pdev)
174 {
175 int retval = -ENOMEM;
176 struct device_node *node;
177 struct device *dev = &pdev->dev;
178 struct cros_ec_platform *ec_platform = dev_get_platdata(dev);
179 struct cros_ec_dev *ec = kzalloc(sizeof(*ec), GFP_KERNEL);
180 struct ec_response_pchg_count pchg_count;
181 int i;
182
183 if (!ec)
184 return retval;
185
186 dev_set_drvdata(dev, ec);
187 ec->ec_dev = dev_get_drvdata(dev->parent);
188 ec->dev = dev;
189 ec->cmd_offset = ec_platform->cmd_offset;
190 ec->features.flags[0] = -1U; /* Not cached yet */
191 ec->features.flags[1] = -1U; /* Not cached yet */
192 device_initialize(&ec->class_dev);
193
194 for (i = 0; i < ARRAY_SIZE(cros_mcu_devices); i++) {
195 /*
196 * Check whether this is actually a dedicated MCU rather
197 * than an standard EC.
198 */
199 if (cros_ec_check_features(ec, cros_mcu_devices[i].id)) {
200 dev_info(dev, "CrOS %s MCU detected\n",
201 cros_mcu_devices[i].desc);
202 /*
203 * Help userspace differentiating ECs from other MCU,
204 * regardless of the probing order.
205 */
206 ec_platform->ec_name = cros_mcu_devices[i].name;
207 break;
208 }
209 }
210
211 /*
212 * Add the class device
213 */
214 ec->class_dev.class = &cros_class;
215 ec->class_dev.parent = dev;
216 ec->class_dev.release = cros_ec_class_release;
217
218 retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name);
219 if (retval) {
220 dev_err(dev, "dev_set_name failed => %d\n", retval);
221 goto failed;
222 }
223
224 retval = device_add(&ec->class_dev);
225 if (retval)
226 goto failed;
227
228 /* check whether this EC is a sensor hub. */
229 if (cros_ec_get_sensor_count(ec) > 0) {
230 retval = mfd_add_hotplug_devices(ec->dev,
231 cros_ec_sensorhub_cells,
232 ARRAY_SIZE(cros_ec_sensorhub_cells));
233 if (retval)
234 dev_err(ec->dev, "failed to add %s subdevice: %d\n",
235 cros_ec_sensorhub_cells->name, retval);
236 }
237
238 /*
239 * The following subdevices can be detected by sending the
240 * EC_FEATURE_GET_CMD Embedded Controller device.
241 */
242 for (i = 0; i < ARRAY_SIZE(cros_subdevices); i++) {
243 if (cros_ec_check_features(ec, cros_subdevices[i].id)) {
244 retval = mfd_add_hotplug_devices(ec->dev,
245 cros_subdevices[i].mfd_cells,
246 cros_subdevices[i].num_cells);
247 if (retval)
248 dev_err(ec->dev,
249 "failed to add %s subdevice: %d\n",
250 cros_subdevices[i].mfd_cells->name,
251 retval);
252 }
253 }
254
255 /*
256 * Lightbar is a special case. Newer devices support autodetection,
257 * but older ones do not.
258 */
259 if (cros_ec_check_features(ec, EC_FEATURE_LIGHTBAR) ||
260 dmi_match(DMI_PRODUCT_NAME, "Link")) {
261 retval = mfd_add_hotplug_devices(ec->dev,
262 cros_ec_lightbar_cells,
263 ARRAY_SIZE(cros_ec_lightbar_cells));
264 if (retval)
265 dev_warn(ec->dev, "failed to add lightbar: %d\n",
266 retval);
267 }
268
269 /*
270 * The PD notifier driver cell is separate since it only needs to be
271 * explicitly added on platforms that don't have the PD notifier ACPI
272 * device entry defined.
273 */
274 if (IS_ENABLED(CONFIG_OF) && ec->ec_dev->dev->of_node) {
275 if (cros_ec_check_features(ec, EC_FEATURE_USB_PD)) {
276 retval = mfd_add_hotplug_devices(ec->dev,
277 cros_usbpd_notify_cells,
278 ARRAY_SIZE(cros_usbpd_notify_cells));
279 if (retval)
280 dev_err(ec->dev,
281 "failed to add PD notify devices: %d\n",
282 retval);
283 }
284 }
285
286 /*
287 * The PCHG device cannot be detected by sending EC_FEATURE_GET_CMD, but
288 * it can be detected by querying the number of peripheral chargers.
289 */
290 retval = cros_ec_cmd(ec->ec_dev, 0, EC_CMD_PCHG_COUNT, NULL, 0,
291 &pchg_count, sizeof(pchg_count));
292 if (retval >= 0 && pchg_count.port_count) {
293 retval = mfd_add_hotplug_devices(ec->dev,
294 cros_ec_pchg_cells,
295 ARRAY_SIZE(cros_ec_pchg_cells));
296 if (retval)
297 dev_warn(ec->dev, "failed to add pchg: %d\n",
298 retval);
299 }
300
301 /*
302 * The following subdevices cannot be detected by sending the
303 * EC_FEATURE_GET_CMD to the Embedded Controller device.
304 */
305 retval = mfd_add_hotplug_devices(ec->dev, cros_ec_platform_cells,
306 ARRAY_SIZE(cros_ec_platform_cells));
307 if (retval)
308 dev_warn(ec->dev,
309 "failed to add cros-ec platform devices: %d\n",
310 retval);
311
312 /* Check whether this EC instance has a VBC NVRAM */
313 node = ec->ec_dev->dev->of_node;
314 if (of_property_read_bool(node, "google,has-vbc-nvram")) {
315 retval = mfd_add_hotplug_devices(ec->dev, cros_ec_vbc_cells,
316 ARRAY_SIZE(cros_ec_vbc_cells));
317 if (retval)
318 dev_warn(ec->dev, "failed to add VBC devices: %d\n",
319 retval);
320 }
321
322 return 0;
323
324 failed:
325 put_device(&ec->class_dev);
326 return retval;
327 }
328
ec_device_remove(struct platform_device * pdev)329 static void ec_device_remove(struct platform_device *pdev)
330 {
331 struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);
332
333 mfd_remove_devices(ec->dev);
334 device_unregister(&ec->class_dev);
335 }
336
337 static const struct platform_device_id cros_ec_id[] = {
338 { DRV_NAME, 0 },
339 { /* sentinel */ }
340 };
341 MODULE_DEVICE_TABLE(platform, cros_ec_id);
342
343 static struct platform_driver cros_ec_dev_driver = {
344 .driver = {
345 .name = DRV_NAME,
346 },
347 .id_table = cros_ec_id,
348 .probe = ec_device_probe,
349 .remove_new = ec_device_remove,
350 };
351
cros_ec_dev_init(void)352 static int __init cros_ec_dev_init(void)
353 {
354 int ret;
355
356 ret = class_register(&cros_class);
357 if (ret) {
358 pr_err(CROS_EC_DEV_NAME ": failed to register device class\n");
359 return ret;
360 }
361
362 ret = platform_driver_register(&cros_ec_dev_driver);
363 if (ret) {
364 pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret);
365 class_unregister(&cros_class);
366 }
367 return ret;
368 }
369
cros_ec_dev_exit(void)370 static void __exit cros_ec_dev_exit(void)
371 {
372 platform_driver_unregister(&cros_ec_dev_driver);
373 class_unregister(&cros_class);
374 }
375
376 module_init(cros_ec_dev_init);
377 module_exit(cros_ec_dev_exit);
378
379 MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>");
380 MODULE_DESCRIPTION("ChromeOS Embedded Controller");
381 MODULE_VERSION("1.0");
382 MODULE_LICENSE("GPL");
383