1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * ChromeOS EC LED Driver
4 *
5 * Copyright (C) 2024 Thomas Weißschuh <linux@weissschuh.net>
6 */
7
8 #include <linux/device.h>
9 #include <linux/leds.h>
10 #include <linux/led-class-multicolor.h>
11 #include <linux/mod_devicetable.h>
12 #include <linux/module.h>
13 #include <linux/platform_device.h>
14 #include <linux/platform_data/cros_ec_commands.h>
15 #include <linux/platform_data/cros_ec_proto.h>
16
17 static const char * const cros_ec_led_functions[] = {
18 [EC_LED_ID_BATTERY_LED] = LED_FUNCTION_CHARGING,
19 [EC_LED_ID_POWER_LED] = LED_FUNCTION_POWER,
20 [EC_LED_ID_ADAPTER_LED] = "adapter",
21 [EC_LED_ID_LEFT_LED] = "left",
22 [EC_LED_ID_RIGHT_LED] = "right",
23 [EC_LED_ID_RECOVERY_HW_REINIT_LED] = "recovery-hw-reinit",
24 [EC_LED_ID_SYSRQ_DEBUG_LED] = "sysrq-debug",
25 };
26
27 static_assert(ARRAY_SIZE(cros_ec_led_functions) == EC_LED_ID_COUNT);
28
29 static const int cros_ec_led_to_linux_id[] = {
30 [EC_LED_COLOR_RED] = LED_COLOR_ID_RED,
31 [EC_LED_COLOR_GREEN] = LED_COLOR_ID_GREEN,
32 [EC_LED_COLOR_BLUE] = LED_COLOR_ID_BLUE,
33 [EC_LED_COLOR_YELLOW] = LED_COLOR_ID_YELLOW,
34 [EC_LED_COLOR_WHITE] = LED_COLOR_ID_WHITE,
35 [EC_LED_COLOR_AMBER] = LED_COLOR_ID_AMBER,
36 };
37
38 static_assert(ARRAY_SIZE(cros_ec_led_to_linux_id) == EC_LED_COLOR_COUNT);
39
40 static const int cros_ec_linux_to_ec_id[] = {
41 [LED_COLOR_ID_RED] = EC_LED_COLOR_RED,
42 [LED_COLOR_ID_GREEN] = EC_LED_COLOR_GREEN,
43 [LED_COLOR_ID_BLUE] = EC_LED_COLOR_BLUE,
44 [LED_COLOR_ID_YELLOW] = EC_LED_COLOR_YELLOW,
45 [LED_COLOR_ID_WHITE] = EC_LED_COLOR_WHITE,
46 [LED_COLOR_ID_AMBER] = EC_LED_COLOR_AMBER,
47 };
48
49 struct cros_ec_led_priv {
50 struct led_classdev_mc led_mc_cdev;
51 struct cros_ec_device *cros_ec;
52 enum ec_led_id led_id;
53 };
54
cros_ec_led_cdev_to_priv(struct led_classdev * led_cdev)55 static inline struct cros_ec_led_priv *cros_ec_led_cdev_to_priv(struct led_classdev *led_cdev)
56 {
57 return container_of(lcdev_to_mccdev(led_cdev), struct cros_ec_led_priv, led_mc_cdev);
58 }
59
60 union cros_ec_led_cmd_data {
61 struct ec_params_led_control req;
62 struct ec_response_led_control resp;
63 };
64
cros_ec_led_send_cmd(struct cros_ec_device * cros_ec,union cros_ec_led_cmd_data * arg)65 static int cros_ec_led_send_cmd(struct cros_ec_device *cros_ec,
66 union cros_ec_led_cmd_data *arg)
67 {
68 int ret;
69
70 ret = cros_ec_cmd(cros_ec, 1, EC_CMD_LED_CONTROL, &arg->req,
71 sizeof(arg->req), &arg->resp, sizeof(arg->resp));
72 if (ret < 0)
73 return ret;
74
75 return 0;
76 }
77
cros_ec_led_trigger_activate(struct led_classdev * led_cdev)78 static int cros_ec_led_trigger_activate(struct led_classdev *led_cdev)
79 {
80 struct cros_ec_led_priv *priv = cros_ec_led_cdev_to_priv(led_cdev);
81 union cros_ec_led_cmd_data arg = {};
82
83 arg.req.led_id = priv->led_id;
84 arg.req.flags = EC_LED_FLAGS_AUTO;
85
86 return cros_ec_led_send_cmd(priv->cros_ec, &arg);
87 }
88
89 static struct led_hw_trigger_type cros_ec_led_trigger_type;
90
91 static struct led_trigger cros_ec_led_trigger = {
92 .name = "chromeos-auto",
93 .trigger_type = &cros_ec_led_trigger_type,
94 .activate = cros_ec_led_trigger_activate,
95 };
96
cros_ec_led_brightness_set_blocking(struct led_classdev * led_cdev,enum led_brightness brightness)97 static int cros_ec_led_brightness_set_blocking(struct led_classdev *led_cdev,
98 enum led_brightness brightness)
99 {
100 struct cros_ec_led_priv *priv = cros_ec_led_cdev_to_priv(led_cdev);
101 union cros_ec_led_cmd_data arg = {};
102 enum ec_led_colors led_color;
103 struct mc_subled *subled;
104 size_t i;
105
106 led_mc_calc_color_components(&priv->led_mc_cdev, brightness);
107
108 arg.req.led_id = priv->led_id;
109
110 for (i = 0; i < priv->led_mc_cdev.num_colors; i++) {
111 subled = &priv->led_mc_cdev.subled_info[i];
112 led_color = cros_ec_linux_to_ec_id[subled->color_index];
113 arg.req.brightness[led_color] = subled->brightness;
114 }
115
116 return cros_ec_led_send_cmd(priv->cros_ec, &arg);
117 }
118
cros_ec_led_count_subleds(struct device * dev,struct ec_response_led_control * resp,unsigned int * max_brightness)119 static int cros_ec_led_count_subleds(struct device *dev,
120 struct ec_response_led_control *resp,
121 unsigned int *max_brightness)
122 {
123 unsigned int range, common_range = 0;
124 int num_subleds = 0;
125 size_t i;
126
127 for (i = 0; i < EC_LED_COLOR_COUNT; i++) {
128 range = resp->brightness_range[i];
129
130 if (!range)
131 continue;
132
133 num_subleds++;
134
135 if (!common_range)
136 common_range = range;
137
138 if (common_range != range) {
139 /* The multicolor LED API expects a uniform max_brightness */
140 dev_err(dev, "Inconsistent LED brightness values\n");
141 return -EINVAL;
142 }
143 }
144
145 if (!num_subleds)
146 return -EINVAL;
147
148 *max_brightness = common_range;
149 return num_subleds;
150 }
151
cros_ec_led_get_color_name(struct led_classdev_mc * led_mc_cdev)152 static const char *cros_ec_led_get_color_name(struct led_classdev_mc *led_mc_cdev)
153 {
154 int color;
155
156 if (led_mc_cdev->num_colors == 1)
157 color = led_mc_cdev->subled_info[0].color_index;
158 else
159 color = LED_COLOR_ID_MULTI;
160
161 return led_get_color_name(color);
162 }
163
cros_ec_led_probe_one(struct device * dev,struct cros_ec_device * cros_ec,enum ec_led_id id)164 static int cros_ec_led_probe_one(struct device *dev, struct cros_ec_device *cros_ec,
165 enum ec_led_id id)
166 {
167 union cros_ec_led_cmd_data arg = {};
168 struct cros_ec_led_priv *priv;
169 struct led_classdev *led_cdev;
170 struct mc_subled *subleds;
171 int i, ret, num_subleds;
172 size_t subled;
173
174 arg.req.led_id = id;
175 arg.req.flags = EC_LED_FLAGS_QUERY;
176 ret = cros_ec_led_send_cmd(cros_ec, &arg);
177 if (ret == -EINVAL)
178 return 0; /* Unknown LED, skip */
179 if (ret == -EOPNOTSUPP)
180 return -ENODEV;
181 if (ret < 0)
182 return ret;
183
184 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
185 if (!priv)
186 return -ENOMEM;
187
188 num_subleds = cros_ec_led_count_subleds(dev, &arg.resp,
189 &priv->led_mc_cdev.led_cdev.max_brightness);
190 if (num_subleds < 0)
191 return num_subleds;
192
193 priv->cros_ec = cros_ec;
194 priv->led_id = id;
195
196 subleds = devm_kcalloc(dev, num_subleds, sizeof(*subleds), GFP_KERNEL);
197 if (!subleds)
198 return -ENOMEM;
199
200 subled = 0;
201 for (i = 0; i < EC_LED_COLOR_COUNT; i++) {
202 if (!arg.resp.brightness_range[i])
203 continue;
204
205 subleds[subled].color_index = cros_ec_led_to_linux_id[i];
206 if (subled == 0)
207 subleds[subled].intensity = 100;
208 subled++;
209 }
210
211 priv->led_mc_cdev.subled_info = subleds;
212 priv->led_mc_cdev.num_colors = num_subleds;
213
214 led_cdev = &priv->led_mc_cdev.led_cdev;
215 led_cdev->brightness_set_blocking = cros_ec_led_brightness_set_blocking;
216 led_cdev->trigger_type = &cros_ec_led_trigger_type;
217 led_cdev->default_trigger = cros_ec_led_trigger.name;
218 led_cdev->hw_control_trigger = cros_ec_led_trigger.name;
219
220 led_cdev->name = devm_kasprintf(dev, GFP_KERNEL, "chromeos:%s:%s",
221 cros_ec_led_get_color_name(&priv->led_mc_cdev),
222 cros_ec_led_functions[id]);
223 if (!led_cdev->name)
224 return -ENOMEM;
225
226 return devm_led_classdev_multicolor_register(dev, &priv->led_mc_cdev);
227 }
228
cros_ec_led_probe(struct platform_device * pdev)229 static int cros_ec_led_probe(struct platform_device *pdev)
230 {
231 struct device *dev = &pdev->dev;
232 struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
233 struct cros_ec_device *cros_ec = ec_dev->ec_dev;
234 int i, ret = 0;
235
236 ret = devm_led_trigger_register(dev, &cros_ec_led_trigger);
237 if (ret)
238 return ret;
239
240 for (i = 0; i < EC_LED_ID_COUNT; i++) {
241 ret = cros_ec_led_probe_one(dev, cros_ec, i);
242 if (ret)
243 break;
244 }
245
246 return ret;
247 }
248
249 static const struct platform_device_id cros_ec_led_id[] = {
250 { "cros-ec-led", 0 },
251 {}
252 };
253
254 static struct platform_driver cros_ec_led_driver = {
255 .driver.name = "cros-ec-led",
256 .probe = cros_ec_led_probe,
257 .id_table = cros_ec_led_id,
258 };
259 module_platform_driver(cros_ec_led_driver);
260
261 MODULE_DEVICE_TABLE(platform, cros_ec_led_id);
262 MODULE_DESCRIPTION("ChromeOS EC LED Driver");
263 MODULE_AUTHOR("Thomas Weißschuh <linux@weissschuh.net");
264 MODULE_LICENSE("GPL");
265