--- /dev/null
+/*
+ * PowerNV LED Driver
+ *
+ * Copyright IBM Corp. 2015
+ *
+ * Author: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
+ * Author: Anshuman Khandual <khandual@linux.vnet.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include <asm/opal.h>
+
+/* 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 void 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;
+ }
+
+ 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 = be64_to_cpu(msg.params[1]);
+ 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);
+}
+
+/*
+ * 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 void 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;
+
+ /* Do not modify LED in unload path */
+ if (powernv_led_common->led_disabled)
+ return;
+
+ mutex_lock(&powernv_led_common->lock);
+ powernv_led_set(powernv_led, value);
+ mutex_unlock(&powernv_led_common->lock);
+}
+
+/* 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) {
+ dev_err(dev,
+ "%s: Memory allocation failed for classdev name\n",
+ __func__);
+ return -ENOMEM;
+ }
+
+ powernv_led->cdev.brightness_set = 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 device_node *np;
+ struct powernv_led_data *powernv_led;
+ struct device *dev = &pdev->dev;
+
+ for_each_child_of_node(led_node, np) {
+ p = of_find_property(np, "led-types", NULL);
+ if (!p)
+ continue;
+
+ while ((cur = of_prop_next_string(p, cur)) != NULL) {
+ powernv_led = devm_kzalloc(dev, sizeof(*powernv_led),
+ GFP_KERNEL);
+ if (!powernv_led) {
+ of_node_put(np);
+ 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) {
+ of_node_put(np);
+ return rc;
+ }
+ } /* while end */
+ }
+
+ return rc;
+}
+
+/* Platform driver probe */
+static int powernv_led_probe(struct platform_device *pdev)
+{
+ struct device_node *led_node;
+ struct powernv_led_common *powernv_led_common;
+ struct device *dev = &pdev->dev;
+
+ led_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 int 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");
+ return 0;
+}
+
+/* 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 <hegdevasant@linux.vnet.ibm.com>");
Code Review / kvmfornfv.git / blobdiff