1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * PowerNV LED Driver |
4 | * |
5 | * Copyright IBM Corp. 2015 |
6 | * |
7 | * Author: Vasant Hegde <hegdevasant@linux.vnet.ibm.com> |
8 | * Author: Anshuman Khandual <khandual@linux.vnet.ibm.com> |
9 | */ |
10 | |
11 | #include <linux/leds.h> |
12 | #include <linux/module.h> |
13 | #include <linux/of.h> |
14 | #include <linux/platform_device.h> |
15 | #include <linux/slab.h> |
16 | #include <linux/types.h> |
17 | |
18 | #include <asm/opal.h> |
19 | |
20 | /* Map LED type to description. */ |
21 | struct led_type_map { |
22 | const int type; |
23 | const char *desc; |
24 | }; |
25 | static const struct led_type_map led_type_map[] = { |
26 | {OPAL_SLOT_LED_TYPE_ID, "identify" }, |
27 | {OPAL_SLOT_LED_TYPE_FAULT, "fault" }, |
28 | {OPAL_SLOT_LED_TYPE_ATTN, "attention" }, |
29 | {-1, NULL}, |
30 | }; |
31 | |
32 | struct powernv_led_common { |
33 | /* |
34 | * By default unload path resets all the LEDs. But on PowerNV |
35 | * platform we want to retain LED state across reboot as these |
36 | * are controlled by firmware. Also service processor can modify |
37 | * the LEDs independent of OS. Hence avoid resetting LEDs in |
38 | * unload path. |
39 | */ |
40 | bool led_disabled; |
41 | |
42 | /* Max supported LED type */ |
43 | __be64 max_led_type; |
44 | |
45 | /* glabal lock */ |
46 | struct mutex lock; |
47 | }; |
48 | |
49 | /* PowerNV LED data */ |
50 | struct powernv_led_data { |
51 | struct led_classdev cdev; |
52 | char *loc_code; /* LED location code */ |
53 | int led_type; /* OPAL_SLOT_LED_TYPE_* */ |
54 | |
55 | struct powernv_led_common *common; |
56 | }; |
57 | |
58 | |
59 | /* Returns OPAL_SLOT_LED_TYPE_* for given led type string */ |
60 | static int powernv_get_led_type(const char *led_type_desc) |
61 | { |
62 | int i; |
63 | |
64 | for (i = 0; i < ARRAY_SIZE(led_type_map); i++) |
65 | if (!strcmp(led_type_map[i].desc, led_type_desc)) |
66 | return led_type_map[i].type; |
67 | |
68 | return -1; |
69 | } |
70 | |
71 | /* |
72 | * This commits the state change of the requested LED through an OPAL call. |
73 | * This function is called from work queue task context when ever it gets |
74 | * scheduled. This function can sleep at opal_async_wait_response call. |
75 | */ |
76 | static int powernv_led_set(struct powernv_led_data *powernv_led, |
77 | enum led_brightness value) |
78 | { |
79 | int rc, token; |
80 | u64 led_mask, led_value = 0; |
81 | __be64 max_type; |
82 | struct opal_msg msg; |
83 | struct device *dev = powernv_led->cdev.dev; |
84 | struct powernv_led_common *powernv_led_common = powernv_led->common; |
85 | |
86 | /* Prepare for the OPAL call */ |
87 | max_type = powernv_led_common->max_led_type; |
88 | led_mask = OPAL_SLOT_LED_STATE_ON << powernv_led->led_type; |
89 | if (value) |
90 | led_value = led_mask; |
91 | |
92 | /* OPAL async call */ |
93 | token = opal_async_get_token_interruptible(); |
94 | if (token < 0) { |
95 | if (token != -ERESTARTSYS) |
96 | dev_err(dev, "%s: Couldn't get OPAL async token\n" , |
97 | __func__); |
98 | return token; |
99 | } |
100 | |
101 | rc = opal_leds_set_ind(token, powernv_led->loc_code, |
102 | led_mask, led_value, &max_type); |
103 | if (rc != OPAL_ASYNC_COMPLETION) { |
104 | dev_err(dev, "%s: OPAL set LED call failed for %s [rc=%d]\n" , |
105 | __func__, powernv_led->loc_code, rc); |
106 | goto out_token; |
107 | } |
108 | |
109 | rc = opal_async_wait_response(token, &msg); |
110 | if (rc) { |
111 | dev_err(dev, |
112 | "%s: Failed to wait for the async response [rc=%d]\n" , |
113 | __func__, rc); |
114 | goto out_token; |
115 | } |
116 | |
117 | rc = opal_get_async_rc(msg); |
118 | if (rc != OPAL_SUCCESS) |
119 | dev_err(dev, "%s : OAPL async call returned failed [rc=%d]\n" , |
120 | __func__, rc); |
121 | |
122 | out_token: |
123 | opal_async_release_token(token); |
124 | return rc; |
125 | } |
126 | |
127 | /* |
128 | * This function fetches the LED state for a given LED type for |
129 | * mentioned LED classdev structure. |
130 | */ |
131 | static enum led_brightness powernv_led_get(struct powernv_led_data *powernv_led) |
132 | { |
133 | int rc; |
134 | __be64 mask, value, max_type; |
135 | u64 led_mask, led_value; |
136 | struct device *dev = powernv_led->cdev.dev; |
137 | struct powernv_led_common *powernv_led_common = powernv_led->common; |
138 | |
139 | /* Fetch all LED status */ |
140 | mask = cpu_to_be64(0); |
141 | value = cpu_to_be64(0); |
142 | max_type = powernv_led_common->max_led_type; |
143 | |
144 | rc = opal_leds_get_ind(powernv_led->loc_code, |
145 | &mask, &value, &max_type); |
146 | if (rc != OPAL_SUCCESS && rc != OPAL_PARTIAL) { |
147 | dev_err(dev, "%s: OPAL get led call failed [rc=%d]\n" , |
148 | __func__, rc); |
149 | return LED_OFF; |
150 | } |
151 | |
152 | led_mask = be64_to_cpu(mask); |
153 | led_value = be64_to_cpu(value); |
154 | |
155 | /* LED status available */ |
156 | if (!((led_mask >> powernv_led->led_type) & OPAL_SLOT_LED_STATE_ON)) { |
157 | dev_err(dev, "%s: LED status not available for %s\n" , |
158 | __func__, powernv_led->cdev.name); |
159 | return LED_OFF; |
160 | } |
161 | |
162 | /* LED status value */ |
163 | if ((led_value >> powernv_led->led_type) & OPAL_SLOT_LED_STATE_ON) |
164 | return LED_FULL; |
165 | |
166 | return LED_OFF; |
167 | } |
168 | |
169 | /* |
170 | * LED classdev 'brightness_get' function. This schedules work |
171 | * to update LED state. |
172 | */ |
173 | static int powernv_brightness_set(struct led_classdev *led_cdev, |
174 | enum led_brightness value) |
175 | { |
176 | struct powernv_led_data *powernv_led = |
177 | container_of(led_cdev, struct powernv_led_data, cdev); |
178 | struct powernv_led_common *powernv_led_common = powernv_led->common; |
179 | int rc; |
180 | |
181 | /* Do not modify LED in unload path */ |
182 | if (powernv_led_common->led_disabled) |
183 | return 0; |
184 | |
185 | mutex_lock(&powernv_led_common->lock); |
186 | rc = powernv_led_set(powernv_led, value); |
187 | mutex_unlock(lock: &powernv_led_common->lock); |
188 | |
189 | return rc; |
190 | } |
191 | |
192 | /* LED classdev 'brightness_get' function */ |
193 | static enum led_brightness powernv_brightness_get(struct led_classdev *led_cdev) |
194 | { |
195 | struct powernv_led_data *powernv_led = |
196 | container_of(led_cdev, struct powernv_led_data, cdev); |
197 | |
198 | return powernv_led_get(powernv_led); |
199 | } |
200 | |
201 | /* |
202 | * This function registers classdev structure for any given type of LED on |
203 | * a given child LED device node. |
204 | */ |
205 | static int powernv_led_create(struct device *dev, |
206 | struct powernv_led_data *powernv_led, |
207 | const char *led_type_desc) |
208 | { |
209 | int rc; |
210 | |
211 | /* Make sure LED type is supported */ |
212 | powernv_led->led_type = powernv_get_led_type(led_type_desc); |
213 | if (powernv_led->led_type == -1) { |
214 | dev_warn(dev, "%s: No support for led type : %s\n" , |
215 | __func__, led_type_desc); |
216 | return -EINVAL; |
217 | } |
218 | |
219 | /* Create the name for classdev */ |
220 | powernv_led->cdev.name = devm_kasprintf(dev, GFP_KERNEL, fmt: "%s:%s" , |
221 | powernv_led->loc_code, |
222 | led_type_desc); |
223 | if (!powernv_led->cdev.name) |
224 | return -ENOMEM; |
225 | |
226 | powernv_led->cdev.brightness_set_blocking = powernv_brightness_set; |
227 | powernv_led->cdev.brightness_get = powernv_brightness_get; |
228 | powernv_led->cdev.brightness = LED_OFF; |
229 | powernv_led->cdev.max_brightness = LED_FULL; |
230 | |
231 | /* Register the classdev */ |
232 | rc = devm_led_classdev_register(parent: dev, led_cdev: &powernv_led->cdev); |
233 | if (rc) { |
234 | dev_err(dev, "%s: Classdev registration failed for %s\n" , |
235 | __func__, powernv_led->cdev.name); |
236 | } |
237 | |
238 | return rc; |
239 | } |
240 | |
241 | /* Go through LED device tree node and register LED classdev structure */ |
242 | static int powernv_led_classdev(struct platform_device *pdev, |
243 | struct device_node *led_node, |
244 | struct powernv_led_common *powernv_led_common) |
245 | { |
246 | const char *cur = NULL; |
247 | int rc = -1; |
248 | struct property *p; |
249 | struct device_node *np; |
250 | struct powernv_led_data *powernv_led; |
251 | struct device *dev = &pdev->dev; |
252 | |
253 | for_each_available_child_of_node(led_node, np) { |
254 | p = of_find_property(np, name: "led-types" , NULL); |
255 | |
256 | while ((cur = of_prop_next_string(prop: p, cur)) != NULL) { |
257 | powernv_led = devm_kzalloc(dev, size: sizeof(*powernv_led), |
258 | GFP_KERNEL); |
259 | if (!powernv_led) { |
260 | of_node_put(node: np); |
261 | return -ENOMEM; |
262 | } |
263 | |
264 | powernv_led->common = powernv_led_common; |
265 | powernv_led->loc_code = (char *)np->name; |
266 | |
267 | rc = powernv_led_create(dev, powernv_led, led_type_desc: cur); |
268 | if (rc) { |
269 | of_node_put(node: np); |
270 | return rc; |
271 | } |
272 | } /* while end */ |
273 | } |
274 | |
275 | return rc; |
276 | } |
277 | |
278 | /* Platform driver probe */ |
279 | static int powernv_led_probe(struct platform_device *pdev) |
280 | { |
281 | struct device_node *led_node; |
282 | struct powernv_led_common *powernv_led_common; |
283 | struct device *dev = &pdev->dev; |
284 | int rc; |
285 | |
286 | led_node = of_find_node_by_path(path: "/ibm,opal/leds" ); |
287 | if (!led_node) { |
288 | dev_err(dev, "%s: LED parent device node not found\n" , |
289 | __func__); |
290 | return -EINVAL; |
291 | } |
292 | |
293 | powernv_led_common = devm_kzalloc(dev, size: sizeof(*powernv_led_common), |
294 | GFP_KERNEL); |
295 | if (!powernv_led_common) { |
296 | rc = -ENOMEM; |
297 | goto out; |
298 | } |
299 | |
300 | mutex_init(&powernv_led_common->lock); |
301 | powernv_led_common->max_led_type = cpu_to_be64(OPAL_SLOT_LED_TYPE_MAX); |
302 | |
303 | platform_set_drvdata(pdev, data: powernv_led_common); |
304 | |
305 | rc = powernv_led_classdev(pdev, led_node, powernv_led_common); |
306 | out: |
307 | of_node_put(node: led_node); |
308 | return rc; |
309 | } |
310 | |
311 | /* Platform driver remove */ |
312 | static void powernv_led_remove(struct platform_device *pdev) |
313 | { |
314 | struct powernv_led_common *powernv_led_common; |
315 | |
316 | /* Disable LED operation */ |
317 | powernv_led_common = platform_get_drvdata(pdev); |
318 | powernv_led_common->led_disabled = true; |
319 | |
320 | /* Destroy lock */ |
321 | mutex_destroy(lock: &powernv_led_common->lock); |
322 | |
323 | dev_info(&pdev->dev, "PowerNV led module unregistered\n" ); |
324 | } |
325 | |
326 | /* Platform driver property match */ |
327 | static const struct of_device_id powernv_led_match[] = { |
328 | { |
329 | .compatible = "ibm,opal-v3-led" , |
330 | }, |
331 | {}, |
332 | }; |
333 | MODULE_DEVICE_TABLE(of, powernv_led_match); |
334 | |
335 | static struct platform_driver powernv_led_driver = { |
336 | .probe = powernv_led_probe, |
337 | .remove_new = powernv_led_remove, |
338 | .driver = { |
339 | .name = "powernv-led-driver" , |
340 | .of_match_table = powernv_led_match, |
341 | }, |
342 | }; |
343 | |
344 | module_platform_driver(powernv_led_driver); |
345 | |
346 | MODULE_LICENSE("GPL v2" ); |
347 | MODULE_DESCRIPTION("PowerNV LED driver" ); |
348 | MODULE_AUTHOR("Vasant Hegde <hegdevasant@linux.vnet.ibm.com>" ); |
349 | |