1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * cros_ec_dev - expose the Chrome OS Embedded Controller to user-space
5 * Copyright (C) 2014 Google, Inc.
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_platform.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>
20 #define DRV_NAME "cros-ec-dev"
22 static struct class cros_class
= {
28 * struct cros_feature_to_name - CrOS feature id to name/short description.
29 * @id: The feature identifier.
30 * @name: Device name associated with the feature id.
31 * @desc: Short name that will be displayed.
33 struct cros_feature_to_name
{
40 * struct cros_feature_to_cells - CrOS feature id to mfd cells association.
41 * @id: The feature identifier.
42 * @mfd_cells: Pointer to the array of mfd cells that needs to be added.
43 * @num_cells: Number of mfd cells into the array.
45 struct cros_feature_to_cells
{
47 const struct mfd_cell
*mfd_cells
;
48 unsigned int num_cells
;
51 static const struct cros_feature_to_name cros_mcu_devices
[] = {
53 .id
= EC_FEATURE_FINGERPRINT
,
54 .name
= CROS_EC_DEV_FP_NAME
,
55 .desc
= "Fingerprint",
59 .name
= CROS_EC_DEV_ISH_NAME
,
60 .desc
= "Integrated Sensor Hub",
64 .name
= CROS_EC_DEV_SCP_NAME
,
65 .desc
= "System Control Processor",
68 .id
= EC_FEATURE_TOUCHPAD
,
69 .name
= CROS_EC_DEV_TP_NAME
,
74 static const struct mfd_cell cros_ec_cec_cells
[] = {
75 { .name
= "cros-ec-cec", },
78 static const struct mfd_cell cros_ec_rtc_cells
[] = {
79 { .name
= "cros-ec-rtc", },
82 static const struct mfd_cell cros_ec_sensorhub_cells
[] = {
83 { .name
= "cros-ec-sensorhub", },
86 static const struct mfd_cell cros_usbpd_charger_cells
[] = {
87 { .name
= "cros-usbpd-charger", },
88 { .name
= "cros-usbpd-logger", },
91 static const struct mfd_cell cros_usbpd_notify_cells
[] = {
92 { .name
= "cros-usbpd-notify", },
95 static const struct cros_feature_to_cells cros_subdevices
[] = {
98 .mfd_cells
= cros_ec_cec_cells
,
99 .num_cells
= ARRAY_SIZE(cros_ec_cec_cells
),
102 .id
= EC_FEATURE_RTC
,
103 .mfd_cells
= cros_ec_rtc_cells
,
104 .num_cells
= ARRAY_SIZE(cros_ec_rtc_cells
),
107 .id
= EC_FEATURE_USB_PD
,
108 .mfd_cells
= cros_usbpd_charger_cells
,
109 .num_cells
= ARRAY_SIZE(cros_usbpd_charger_cells
),
113 static const struct mfd_cell cros_ec_platform_cells
[] = {
114 { .name
= "cros-ec-chardev", },
115 { .name
= "cros-ec-debugfs", },
116 { .name
= "cros-ec-sysfs", },
117 { .name
= "cros-ec-pchg", },
120 static const struct mfd_cell cros_ec_lightbar_cells
[] = {
121 { .name
= "cros-ec-lightbar", }
124 static const struct mfd_cell cros_ec_vbc_cells
[] = {
125 { .name
= "cros-ec-vbc", }
128 static void cros_ec_class_release(struct device
*dev
)
130 kfree(to_cros_ec_dev(dev
));
133 static int ec_device_probe(struct platform_device
*pdev
)
135 int retval
= -ENOMEM
;
136 struct device_node
*node
;
137 struct device
*dev
= &pdev
->dev
;
138 struct cros_ec_platform
*ec_platform
= dev_get_platdata(dev
);
139 struct cros_ec_dev
*ec
= kzalloc(sizeof(*ec
), GFP_KERNEL
);
145 dev_set_drvdata(dev
, ec
);
146 ec
->ec_dev
= dev_get_drvdata(dev
->parent
);
148 ec
->cmd_offset
= ec_platform
->cmd_offset
;
149 ec
->features
.flags
[0] = -1U; /* Not cached yet */
150 ec
->features
.flags
[1] = -1U; /* Not cached yet */
151 device_initialize(&ec
->class_dev
);
153 for (i
= 0; i
< ARRAY_SIZE(cros_mcu_devices
); i
++) {
155 * Check whether this is actually a dedicated MCU rather
156 * than an standard EC.
158 if (cros_ec_check_features(ec
, cros_mcu_devices
[i
].id
)) {
159 dev_info(dev
, "CrOS %s MCU detected\n",
160 cros_mcu_devices
[i
].desc
);
162 * Help userspace differentiating ECs from other MCU,
163 * regardless of the probing order.
165 ec_platform
->ec_name
= cros_mcu_devices
[i
].name
;
171 * Add the class device
173 ec
->class_dev
.class = &cros_class
;
174 ec
->class_dev
.parent
= dev
;
175 ec
->class_dev
.release
= cros_ec_class_release
;
177 retval
= dev_set_name(&ec
->class_dev
, "%s", ec_platform
->ec_name
);
179 dev_err(dev
, "dev_set_name failed => %d\n", retval
);
183 retval
= device_add(&ec
->class_dev
);
187 /* check whether this EC is a sensor hub. */
188 if (cros_ec_get_sensor_count(ec
) > 0) {
189 retval
= mfd_add_hotplug_devices(ec
->dev
,
190 cros_ec_sensorhub_cells
,
191 ARRAY_SIZE(cros_ec_sensorhub_cells
));
193 dev_err(ec
->dev
, "failed to add %s subdevice: %d\n",
194 cros_ec_sensorhub_cells
->name
, retval
);
198 * The following subdevices can be detected by sending the
199 * EC_FEATURE_GET_CMD Embedded Controller device.
201 for (i
= 0; i
< ARRAY_SIZE(cros_subdevices
); i
++) {
202 if (cros_ec_check_features(ec
, cros_subdevices
[i
].id
)) {
203 retval
= mfd_add_hotplug_devices(ec
->dev
,
204 cros_subdevices
[i
].mfd_cells
,
205 cros_subdevices
[i
].num_cells
);
208 "failed to add %s subdevice: %d\n",
209 cros_subdevices
[i
].mfd_cells
->name
,
215 * Lightbar is a special case. Newer devices support autodetection,
216 * but older ones do not.
218 if (cros_ec_check_features(ec
, EC_FEATURE_LIGHTBAR
) ||
219 dmi_match(DMI_PRODUCT_NAME
, "Link")) {
220 retval
= mfd_add_hotplug_devices(ec
->dev
,
221 cros_ec_lightbar_cells
,
222 ARRAY_SIZE(cros_ec_lightbar_cells
));
224 dev_warn(ec
->dev
, "failed to add lightbar: %d\n",
229 * The PD notifier driver cell is separate since it only needs to be
230 * explicitly added on platforms that don't have the PD notifier ACPI
231 * device entry defined.
233 if (IS_ENABLED(CONFIG_OF
) && ec
->ec_dev
->dev
->of_node
) {
234 if (cros_ec_check_features(ec
, EC_FEATURE_USB_PD
)) {
235 retval
= mfd_add_hotplug_devices(ec
->dev
,
236 cros_usbpd_notify_cells
,
237 ARRAY_SIZE(cros_usbpd_notify_cells
));
240 "failed to add PD notify devices: %d\n",
246 * The following subdevices cannot be detected by sending the
247 * EC_FEATURE_GET_CMD to the Embedded Controller device.
249 retval
= mfd_add_hotplug_devices(ec
->dev
, cros_ec_platform_cells
,
250 ARRAY_SIZE(cros_ec_platform_cells
));
253 "failed to add cros-ec platform devices: %d\n",
256 /* Check whether this EC instance has a VBC NVRAM */
257 node
= ec
->ec_dev
->dev
->of_node
;
258 if (of_property_read_bool(node
, "google,has-vbc-nvram")) {
259 retval
= mfd_add_hotplug_devices(ec
->dev
, cros_ec_vbc_cells
,
260 ARRAY_SIZE(cros_ec_vbc_cells
));
262 dev_warn(ec
->dev
, "failed to add VBC devices: %d\n",
269 put_device(&ec
->class_dev
);
273 static int ec_device_remove(struct platform_device
*pdev
)
275 struct cros_ec_dev
*ec
= dev_get_drvdata(&pdev
->dev
);
277 mfd_remove_devices(ec
->dev
);
278 device_unregister(&ec
->class_dev
);
282 static const struct platform_device_id cros_ec_id
[] = {
286 MODULE_DEVICE_TABLE(platform
, cros_ec_id
);
288 static struct platform_driver cros_ec_dev_driver
= {
292 .id_table
= cros_ec_id
,
293 .probe
= ec_device_probe
,
294 .remove
= ec_device_remove
,
297 static int __init
cros_ec_dev_init(void)
301 ret
= class_register(&cros_class
);
303 pr_err(CROS_EC_DEV_NAME
": failed to register device class\n");
307 /* Register the driver */
308 ret
= platform_driver_register(&cros_ec_dev_driver
);
310 pr_warn(CROS_EC_DEV_NAME
": can't register driver: %d\n", ret
);
316 class_unregister(&cros_class
);
320 static void __exit
cros_ec_dev_exit(void)
322 platform_driver_unregister(&cros_ec_dev_driver
);
323 class_unregister(&cros_class
);
326 module_init(cros_ec_dev_init
);
327 module_exit(cros_ec_dev_exit
);
329 MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>");
330 MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller");
331 MODULE_VERSION("1.0");
332 MODULE_LICENSE("GPL");