// SPDX-License-Identifier: GPL-2.0-or-later /* * PowerNV LED Driver * * Copyright IBM Corp. 2015 * * Author: Vasant Hegde * Author: Anshuman Khandual */ #include #include #include #include #include #include #include /* Map LED type to description. */ struct led_type_map { const int type; const char *desc; }; static const struct led_type_map led_type_map[] = { {OPAL_SLOT_LED_TYPE_ID, "identify"}, {OPAL_SLOT_LED_TYPE_FAULT, "fault"}, {OPAL_SLOT_LED_TYPE_ATTN, "attention"}, {-1, NULL}, }; struct powernv_led_common { /* * By default unload path resets all the LEDs. But on PowerNV * platform we want to retain LED state across reboot as these * are controlled by firmware. Also service processor can modify * the LEDs independent of OS. Hence avoid resetting LEDs in * unload path. */ bool led_disabled; /* Max supported LED type */ __be64 max_led_type; /* glabal lock */ struct mutex lock; }; /* PowerNV LED data */ struct powernv_led_data { struct led_classdev cdev; char *loc_code; /* LED location code */ int led_type; /* OPAL_SLOT_LED_TYPE_* */ struct powernv_led_common *common; }; /* Returns OPAL_SLOT_LED_TYPE_* for given led type string */ static int powernv_get_led_type(const char *led_type_desc) { int i; for (i = 0; i < ARRAY_SIZE(led_type_map); i++) if (!strcmp(led_type_map[i].desc, led_type_desc)) return led_type_map[i].type; return -1; } /* * This commits the state change of the requested LED through an OPAL call. * This function is called from work queue task context when ever it gets * scheduled. This function can sleep at opal_async_wait_response call. */ static int powernv_led_set(struct powernv_led_data *powernv_led, enum led_brightness value) { int rc, token; u64 led_mask, led_value = 0; __be64 max_type; struct opal_msg msg; struct device *dev = powernv_led->cdev.dev; struct powernv_led_common *powernv_led_common = powernv_led->common; /* Prepare for the OPAL call */ max_type = powernv_led_common->max_led_type; led_mask = OPAL_SLOT_LED_STATE_ON << powernv_led->led_type; if (value) led_value = led_mask; /* OPAL async call */ token = opal_async_get_token_interruptible(); if (token < 0) { if (token != -ERESTARTSYS) dev_err(dev, "%s: Couldn't get OPAL async token\n", __func__); return token; } rc = opal_leds_set_ind(token, powernv_led->loc_code, led_mask, led_value, &max_type); if (rc != OPAL_ASYNC_COMPLETION) { dev_err(dev, "%s: OPAL set LED call failed for %s [rc=%d]\n", __func__, powernv_led->loc_code, rc); goto out_token; } rc = opal_async_wait_response(token, &msg); if (rc) { dev_err(dev, "%s: Failed to wait for the async response [rc=%d]\n", __func__, rc); goto out_token; } rc = opal_get_async_rc(msg); if (rc != OPAL_SUCCESS) dev_err(dev, "%s : OAPL async call returned failed [rc=%d]\n", __func__, rc); out_token: opal_async_release_token(token); return rc; } /* * This function fetches the LED state for a given LED type for * mentioned LED classdev structure. */ static enum led_brightness powernv_led_get(struct powernv_led_data *powernv_led) { int rc; __be64 mask, value, max_type; u64 led_mask, led_value; struct device *dev = powernv_led->cdev.dev; struct powernv_led_common *powernv_led_common = powernv_led->common; /* Fetch all LED status */ mask = cpu_to_be64(0); value = cpu_to_be64(0); max_type = powernv_led_common->max_led_type; rc = opal_leds_get_ind(powernv_led->loc_code, &mask, &value, &max_type); if (rc != OPAL_SUCCESS && rc != OPAL_PARTIAL) { dev_err(dev, "%s: OPAL get led call failed [rc=%d]\n", __func__, rc); return LED_OFF; } led_mask = be64_to_cpu(mask); led_value = be64_to_cpu(value); /* LED status available */ if (!((led_mask >> powernv_led->led_type) & OPAL_SLOT_LED_STATE_ON)) { dev_err(dev, "%s: LED status not available for %s\n", __func__, powernv_led->cdev.name); return LED_OFF; } /* LED status value */ if ((led_value >> powernv_led->led_type) & OPAL_SLOT_LED_STATE_ON) return LED_FULL; return LED_OFF; } /* * LED classdev 'brightness_get' function. This schedules work * to update LED state. */ static int powernv_brightness_set(struct led_classdev *led_cdev, enum led_brightness value) { struct powernv_led_data *powernv_led = container_of(led_cdev, struct powernv_led_data, cdev); struct powernv_led_common *powernv_led_common = powernv_led->common; int rc; /* Do not modify LED in unload path */ if (powernv_led_common->led_disabled) return 0; mutex_lock(&powernv_led_common->lock); rc = powernv_led_set(powernv_led, value); mutex_unlock(&powernv_led_common->lock); return rc; } /* LED classdev 'brightness_get' function */ static enum led_brightness powernv_brightness_get(struct led_classdev *led_cdev) { struct powernv_led_data *powernv_led = container_of(led_cdev, struct powernv_led_data, cdev); return powernv_led_get(powernv_led); } /* * This function registers classdev structure for any given type of LED on * a given child LED device node. */ static int powernv_led_create(struct device *dev, struct powernv_led_data *powernv_led, const char *led_type_desc) { int rc; /* Make sure LED type is supported */ powernv_led->led_type = powernv_get_led_type(led_type_desc); if (powernv_led->led_type == -1) { dev_warn(dev, "%s: No support for led type : %s\n", __func__, led_type_desc); return -EINVAL; } /* Create the name for classdev */ powernv_led->cdev.name = devm_kasprintf(dev, GFP_KERNEL, "%s:%s", powernv_led->loc_code, led_type_desc); if (!powernv_led->cdev.name) return -ENOMEM; powernv_led->cdev.brightness_set_blocking = powernv_brightness_set; powernv_led->cdev.brightness_get = powernv_brightness_get; powernv_led->cdev.brightness = LED_OFF; powernv_led->cdev.max_brightness = LED_FULL; /* Register the classdev */ rc = devm_led_classdev_register(dev, &powernv_led->cdev); if (rc) { dev_err(dev, "%s: Classdev registration failed for %s\n", __func__, powernv_led->cdev.name); } return rc; } /* Go through LED device tree node and register LED classdev structure */ static int powernv_led_classdev(struct platform_device *pdev, struct device_node *led_node, struct powernv_led_common *powernv_led_common) { const char *cur = NULL; int rc = -1; struct property *p; struct powernv_led_data *powernv_led; struct device *dev = &pdev->dev; for_each_available_child_of_node_scoped(led_node, np) { p = of_find_property(np, "led-types", NULL); while ((cur = of_prop_next_string(p, cur)) != NULL) { powernv_led = devm_kzalloc(dev, sizeof(*powernv_led), GFP_KERNEL); if (!powernv_led) return -ENOMEM; powernv_led->common = powernv_led_common; powernv_led->loc_code = (char *)np->name; rc = powernv_led_create(dev, powernv_led, cur); if (rc) return rc; } /* while end */ } return rc; } /* Platform driver probe */ static int powernv_led_probe(struct platform_device *pdev) { struct powernv_led_common *powernv_led_common; struct device *dev = &pdev->dev; struct device_node *led_node __free(device_node) = of_find_node_by_path("/ibm,opal/leds"); if (!led_node) { dev_err(dev, "%s: LED parent device node not found\n", __func__); return -EINVAL; } powernv_led_common = devm_kzalloc(dev, sizeof(*powernv_led_common), GFP_KERNEL); if (!powernv_led_common) return -ENOMEM; mutex_init(&powernv_led_common->lock); powernv_led_common->max_led_type = cpu_to_be64(OPAL_SLOT_LED_TYPE_MAX); platform_set_drvdata(pdev, powernv_led_common); return powernv_led_classdev(pdev, led_node, powernv_led_common); } /* Platform driver remove */ static void powernv_led_remove(struct platform_device *pdev) { struct powernv_led_common *powernv_led_common; /* Disable LED operation */ powernv_led_common = platform_get_drvdata(pdev); powernv_led_common->led_disabled = true; /* Destroy lock */ mutex_destroy(&powernv_led_common->lock); dev_info(&pdev->dev, "PowerNV led module unregistered\n"); } /* Platform driver property match */ static const struct of_device_id powernv_led_match[] = { { .compatible = "ibm,opal-v3-led", }, {}, }; MODULE_DEVICE_TABLE(of, powernv_led_match); static struct platform_driver powernv_led_driver = { .probe = powernv_led_probe, .remove = powernv_led_remove, .driver = { .name = "powernv-led-driver", .of_match_table = powernv_led_match, }, }; module_platform_driver(powernv_led_driver); MODULE_LICENSE("GPL v2"); MODULE_DESCRIPTION("PowerNV LED driver"); MODULE_AUTHOR("Vasant Hegde ");