diff options
| -rw-r--r-- | Documentation/devicetree/bindings/leds/leds-powernv.txt | 26 | ||||
| -rw-r--r-- | drivers/leds/Kconfig | 11 | ||||
| -rw-r--r-- | drivers/leds/Makefile | 1 | ||||
| -rw-r--r-- | drivers/leds/leds-powernv.c | 345 |
4 files changed, 383 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/leds/leds-powernv.txt b/Documentation/devicetree/bindings/leds/leds-powernv.txt new file mode 100644 index 000000000000..66655690f749 --- /dev/null +++ b/Documentation/devicetree/bindings/leds/leds-powernv.txt @@ -0,0 +1,26 @@ +Device Tree binding for LEDs on IBM Power Systems +------------------------------------------------- + +Required properties: +- compatible : Should be "ibm,opal-v3-led". +- led-mode : Should be "lightpath" or "guidinglight". + +Each location code of FRU/Enclosure must be expressed in the +form of a sub-node. + +Required properties for the sub nodes: +- led-types : Supported LED types (attention/identify/fault) provided + in the form of string array. + +Example: + +leds { + compatible = "ibm,opal-v3-led"; + led-mode = "lightpath"; + + U78C9.001.RST0027-P1-C1 { + led-types = "identify", "fault"; + }; + ... + ... +}; diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig index 9ad35f72ab4c..f218cc3acc10 100644 --- a/drivers/leds/Kconfig +++ b/drivers/leds/Kconfig @@ -560,6 +560,17 @@ config LEDS_BLINKM This option enables support for the BlinkM RGB LED connected through I2C. Say Y to enable support for the BlinkM LED. +config LEDS_POWERNV + tristate "LED support for PowerNV Platform" + depends on LEDS_CLASS + depends on PPC_POWERNV + depends on OF + help + This option enables support for the system LEDs present on + PowerNV platforms. Say 'y' to enable this support in kernel. + To compile this driver as a module, choose 'm' here: the module + will be called leds-powernv. + config LEDS_SYSCON bool "LED support for LEDs on system controllers" depends on LEDS_CLASS=y diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile index 8d6a24a2f513..6a943d16ecab 100644 --- a/drivers/leds/Makefile +++ b/drivers/leds/Makefile @@ -65,6 +65,7 @@ obj-$(CONFIG_LEDS_VERSATILE) += leds-versatile.o obj-$(CONFIG_LEDS_MENF21BMC) += leds-menf21bmc.o obj-$(CONFIG_LEDS_PM8941_WLED) += leds-pm8941-wled.o obj-$(CONFIG_LEDS_KTD2692) += leds-ktd2692.o +obj-$(CONFIG_LEDS_POWERNV) += leds-powernv.o # LED SPI Drivers obj-$(CONFIG_LEDS_DAC124S085) += leds-dac124s085.o diff --git a/drivers/leds/leds-powernv.c b/drivers/leds/leds-powernv.c new file mode 100644 index 000000000000..a2fea192573b --- /dev/null +++ b/drivers/leds/leds-powernv.c @@ -0,0 +1,345 @@ +/* + * 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, POWERNV_LED_TYPE_IDENTIFY}, + {OPAL_SLOT_LED_TYPE_FAULT, POWERNV_LED_TYPE_FAULT}, + {OPAL_SLOT_LED_TYPE_ATTN, POWERNV_LED_TYPE_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) + 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 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>"); |