From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jacek Anaszewski Subject: Re: [PATCH v4 3/3] leds/powernv: Add driver for PowerNV platform Date: Thu, 30 Apr 2015 16:29:25 +0200 Message-ID: <55423C45.3070601@samsung.com> References: <20150428100535.26912.29607.stgit@localhost.localdomain> <20150428101008.26912.38735.stgit@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mailout3.w1.samsung.com ([210.118.77.13]:26801 "EHLO mailout3.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750705AbbD3O3a (ORCPT ); Thu, 30 Apr 2015 10:29:30 -0400 Received: from eucpsbgm1.samsung.com (unknown [203.254.199.244]) by mailout3.w1.samsung.com (Oracle Communications Messaging Server 7.0.5.31.0 64bit (built May 5 2014)) with ESMTP id <0NNM005VXIX3E350@mailout3.w1.samsung.com> for linux-leds@vger.kernel.org; Thu, 30 Apr 2015 15:29:27 +0100 (BST) In-reply-to: <20150428101008.26912.38735.stgit@localhost.localdomain> Sender: linux-leds-owner@vger.kernel.org List-Id: linux-leds@vger.kernel.org To: Vasant Hegde Cc: linuxppc-dev@lists.ozlabs.org, linux-leds@vger.kernel.org, stewart@linux.vnet.ibm.com, j.anaszewski81@gmail.com, benh@kernel.crashing.org, cooloney@gmail.com, rpurdie@rpsys.net, mpe@ellerman.id.au, khandual@linux.vnet.ibm.com Hi Vasant, On 04/28/2015 12:10 PM, Vasant Hegde wrote: > This patch implements LED driver for PowerNV platform using the existing > generic LED class framework. > > PowerNV platform has below type of LEDs: > - System attention > Indicates there is a problem with the system that needs attention. > - Identify > Helps the user locate/identify a particular FRU or resource in the > system. > - Fault > Indicates there is a problem with the FRU or resource at the > location with which the indicator is associated. > > We register classdev structures for all individual LEDs detected on the > system through LED specific device tree nodes. Device tree nodes specify > what all kind of LEDs present on the same location code. It registers > LED classdev structure for each of them. > > All the system LEDs can be found in the same regular path /sys/class/leds/. > We don't use LED colors. We use LED node and led-types property to form > LED classdev. Our LEDs have names in this format. > > : > > Any positive brightness value would turn on the LED and a zero value would > turn off the LED. The driver will return LED_FULL (255) for any turned on > LED and LED_OFF (0) for any turned off LED. > > As per the LED class framework, the 'brightness_set' function should not > sleep. Hence these functions have been implemented through global work > queue tasks which might sleep on OPAL async call completion. > > The platform level implementation of LED get and set state has been achieved > through OPAL calls. These calls are made available for the driver by > exporting from architecture specific codes. > > Signed-off-by: Vasant Hegde > Signed-off-by: Anshuman Khandual > Acked-by: Stewart Smith > Tested-by: Stewart Smith > > --- > Changes in v4: > - s/u64/__be64/g for big endian data we get from firmware > - Addressed review comments from Jacek. Major once are: > Removed list in powernv_led_data structure > s/kzalloc/devm_kzalloc/ > Removed compatible property from documentation > s/powernv_led_set_queue/powernv_brightness_set/ > - Removed LED specific brightness_set/get function. Instead this version > uses single function to queue all LED set/get requests. Later we use > LED name to detect LED type and value. > - Removed hardcoded LED type used in previous version. Instead we use > led-types property to form LED classdev. > > > Changes in v3: > - Addressed review comments from Jacek. Major once are: > Replaced spin lock and mutex and removed redundant structures > Replaced pr_* with dev_* > Moved OPAL platform sepcific part to separate patch > Moved repteated code to common function > Added device tree documentation for LEDs > > > Changes in v2: > - Added System Attention indicator support > - Moved common code to powernv_led_set_queue() > > > .../devicetree/bindings/leds/leds-powernv.txt | 29 + > drivers/leds/Kconfig | 11 > drivers/leds/Makefile | 1 > drivers/leds/leds-powernv.c | 472 ++++++++++++++++++++ > 4 files changed, 513 insertions(+) > create mode 100644 Documentation/devicetree/bindings/leds/leds-powernv.txt > create mode 100644 drivers/leds/leds-powernv.c > > diff --git a/Documentation/devicetree/bindings/leds/leds-powernv.txt b/Documentation/devicetree/bindings/leds/leds-powernv.txt > new file mode 100644 > index 0000000..6bb0e7e > --- /dev/null > +++ b/Documentation/devicetree/bindings/leds/leds-powernv.txt > @@ -0,0 +1,29 @@ > +Device Tree binding for LEDs on IBM Power Systems > +------------------------------------------------- > + > +The 'led' node under '/ibm,opal' lists service indicators available in the > +system and their capabilities. > + > +led { > + compatible = "ibm,opal-v3-led"; > + phandle = <0x1000006b>; > + linux,phandle = <0x1000006b>; > + led-mode = "lightpath"; > + > + U78C9.001.RST0027-P1-C1 { > + led-types = "identify", "fault"; > + led-loc = "descendent"; > + phandle = <0x1000006f>; > + linux,phandle = <0x1000006f>; > + }; > + ... > + ... > +}; > + > +Each node under 'led' node describes location code of FRU/Enclosure. > + > +The properties under each node: > + > + led-types : Supported LED types (attention/identify/fault). > + > + led-loc : enclosure/descendent(FRU) location code. DT documentation it usually constructed so that properties are described in the beginning and the file ends with an example. Also last time I mistakenly requested to remove description of compatible property, but it should also be present here and the entry should described it in detail, like: - compatible : Should be "ibm,opal-v3-led". Please refer to the other bindings, I will express my opinion on the LED part after powerpc maintainer will ack DT bindings. > diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig > index 25b320d..2ea0849 100644 > --- a/drivers/leds/Kconfig > +++ b/drivers/leds/Kconfig > @@ -508,6 +508,17 @@ 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 cbba921..604ffc9 100644 > --- a/drivers/leds/Makefile > +++ b/drivers/leds/Makefile > @@ -58,6 +58,7 @@ obj-$(CONFIG_LEDS_BLINKM) += leds-blinkm.o > obj-$(CONFIG_LEDS_SYSCON) += leds-syscon.o > obj-$(CONFIG_LEDS_VERSATILE) += leds-versatile.o > obj-$(CONFIG_LEDS_MENF21BMC) += leds-menf21bmc.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 0000000..bea46fd > --- /dev/null > +++ b/drivers/leds/leds-powernv.c > @@ -0,0 +1,472 @@ > +/* > + * PowerNV LED Driver > + * > + * Copyright IBM Corp. 2015 > + * > + * Author: Vasant Hegde > + * Author: Anshuman Khandual > + * > + * 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 > +#include > +#include > +#include > +#include > +#include > + > +#include > + > +/* > + * LED support for PowerNV platform: > + * - Identify and fault LEDs are overloaded (meaning we use single LED to > + * represent both state). > + * Physical LED state : off = normal, blinking = identify, solid = fault > + * Hardware takes care of maintaining/changing LED state. From user point > + * of view these are two different LEDs. Hence we use separate led > + * classsdev for identify and fault. > + * - 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. > + */ > + > +/* Disable LED support in unload path */ > +static bool led_disabled; > + > +/* 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}, > +}; > + > +/* > + * LED set routines have been implemented as work queue tasks scheduled > + * on the global work queue. Individual task calls OPAL interface to set > + * the LED state which might sleep for some time. > + */ > +struct powernv_led_data { > + struct led_classdev cdev; > + enum led_brightness value; /* Brightness value */ > + struct mutex lock; > + struct work_struct work_led; /* LED update workqueue */ > +}; > + > +struct powernv_leds_priv { > + int num_leds; > + struct powernv_led_data powernv_leds[]; > +}; > + > + > +static inline int sizeof_powernv_leds_priv(int num_leds) > +{ > + return sizeof(struct powernv_leds_priv) + > + (sizeof(struct powernv_led_data) * num_leds); > +} > + > +/* Returns OPAL_SLOT_LED_TYPE_* for given led type string */ > +static int powernv_get_led_type(struct led_classdev *led_cdev) > +{ > + char *desc; > + int i; > + > + desc = strstr(led_cdev->name, ":"); > + if (!desc) > + return -1; > + desc++; > + if (!desc) > + return -1; > + > + for (i = 0; i < ARRAY_SIZE(led_type_map); i++) > + if (!strcmp(led_type_map[i].desc, desc)) > + return led_type_map[i].type; > + > + return -1; > +} > + > +/* This function gets LED location code for given LED classdev */ > +static char *powernv_get_location_code(struct led_classdev *led_cdev) > +{ > + char *loc_code; > + char *colon; > + > + /* Location code of the LED */ > + loc_code = kasprintf(GFP_KERNEL, "%s", led_cdev->name); > + if (!loc_code) { > + dev_err(led_cdev->dev, > + "%s: Memory allocation failed\n", __func__); > + return NULL; > + } > + > + colon = strstr(loc_code, ":"); > + if (!colon) { > + kfree(loc_code); > + return NULL; > + } > + > + *colon = '\0'; > + return loc_code; > +} > + > +/* > + * 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 led_classdev *led_cdev, > + enum led_brightness value) > +{ > + char *loc_code; > + int rc, token, led_type; > + u64 led_mask, led_value = 0; > + __be64 max_led_type; > + struct opal_msg msg; > + > + led_type = powernv_get_led_type(led_cdev); > + if (led_type == -1) > + return; > + > + loc_code = powernv_get_location_code(led_cdev); > + if (!loc_code) > + return; > + > + /* Prepare for the OPAL call */ > + max_led_type = cpu_to_be64(OPAL_SLOT_LED_TYPE_MAX); > + led_mask = OPAL_SLOT_LED_STATE_ON << 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(led_cdev->dev, > + "%s: Couldn't get OPAL async token\n", > + __func__); > + goto out_loc; > + } > + > + rc = opal_leds_set_ind(token, loc_code, > + led_mask, led_value, &max_led_type); > + if (rc != OPAL_ASYNC_COMPLETION) { > + dev_err(led_cdev->dev, > + "%s: OPAL set LED call failed for %s [rc=%d]\n", > + __func__, loc_code, rc); > + goto out_token; > + } > + > + rc = opal_async_wait_response(token, &msg); > + if (rc) { > + dev_err(led_cdev->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(led_cdev->dev, > + "%s : OAPL async call returned failed [rc=%d]\n", > + __func__, rc); > + > +out_token: > + opal_async_release_token(token); > + > +out_loc: > + kfree(loc_code); > +} > + > +/* > + * This function fetches the LED state for a given LED type for > + * mentioned LED classdev structure. > + */ > +static enum led_brightness powernv_led_get(struct led_classdev *led_cdev) > +{ > + char *loc_code; > + int rc, led_type; > + __be64 led_mask, led_value, max_led_type; > + > + led_type = powernv_get_led_type(led_cdev); > + if (led_type == -1) > + return LED_OFF; > + > + loc_code = powernv_get_location_code(led_cdev); > + if (!loc_code) > + return LED_OFF; > + > + /* Fetch all LED status */ > + led_mask = cpu_to_be64(0); > + led_value = cpu_to_be64(0); > + max_led_type = cpu_to_be64(OPAL_SLOT_LED_TYPE_MAX); > + > + rc = opal_leds_get_ind(loc_code, &led_mask, &led_value, &max_led_type); > + if (rc != OPAL_SUCCESS && rc != OPAL_PARTIAL) { > + dev_err(led_cdev->dev, > + "%s: OPAL get led call failed [rc=%d]\n", > + __func__, rc); > + goto led_fail; > + } > + > + led_mask = be64_to_cpu(led_mask); > + led_value = be64_to_cpu(led_value); > + > + /* LED status available */ > + if (!((led_mask >> led_type) & OPAL_SLOT_LED_STATE_ON)) { > + dev_err(led_cdev->dev, > + "%s: LED status not available for %s\n", > + __func__, led_cdev->name); > + goto led_fail; > + } > + > + /* LED status value */ > + if ((led_value >> led_type) & OPAL_SLOT_LED_STATE_ON) { > + kfree(loc_code); > + return LED_FULL; > + } > + > +led_fail: > + kfree(loc_code); > + return LED_OFF; > +} > + > +/* Execute LED set task for given led classdev */ > +static void powernv_deferred_led_set(struct work_struct *work) > +{ > + struct powernv_led_data *powernv_led = > + container_of(work, struct powernv_led_data, work_led); > + > + mutex_lock(&powernv_led->lock); > + powernv_led_set(&powernv_led->cdev, powernv_led->value); > + mutex_unlock(&powernv_led->lock); > +} > + > +/* > + * 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); > + > + /* Do not modify LED in unload path */ > + if (led_disabled) > + return; > + > + /* Prepare the request */ > + powernv_led->value = value; > + > + /* Schedule the new task */ > + schedule_work(&powernv_led->work_led); > +} > + > +/* LED classdev 'brightness_get' function */ > +static enum led_brightness > +powernv_brightness_get(struct led_classdev *led_cdev) > +{ > + return powernv_led_get(led_cdev); > +} > + > + > +/* > + * 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_name, const char *led_type_desc) > +{ > + int rc; > + > + /* Create the name for classdev */ > + powernv_led->cdev.name = kasprintf(GFP_KERNEL, "%s:%s", > + led_name, led_type_desc); > + if (!powernv_led->cdev.name) { > + dev_err(dev, > + "%s: Memory allocation failed for classdev name\n", > + __func__); > + return -ENOMEM; > + } > + > + /* Make sure LED type is supported */ > + if (powernv_get_led_type(&powernv_led->cdev) == -1) { > + kfree(powernv_led->cdev.name); > + return -EINVAL; > + } > + > + 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; > + > + mutex_init(&powernv_led->lock); > + INIT_WORK(&powernv_led->work_led, powernv_deferred_led_set); > + > + /* Register the classdev */ > + rc = led_classdev_register(dev, &powernv_led->cdev); > + if (rc) { > + dev_err(dev, "%s: Classdev registration failed for %s\n", > + __func__, powernv_led->cdev.name); > + kfree(powernv_led->cdev.name); > + } > + > + return rc; > +} > + > +/* Unregister classdev structure for any given LED */ > +static void powernv_led_delete(struct powernv_led_data *powernv_led) > +{ > + led_classdev_unregister(&powernv_led->cdev); > +} > + > +/* 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_leds_priv *priv, int num_leds) > +{ > + const char *cur = NULL; > + int i, 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 = &priv->powernv_leds[priv->num_leds++]; > + if (priv->num_leds > num_leds) { > + rc = -ENOMEM; > + goto classdev_fail; > + } > + rc = powernv_led_create(dev, > + powernv_led, np->name, cur); > + if (rc) > + goto classdev_fail; > + } /* while end */ > + } > + > + platform_set_drvdata(pdev, priv); > + return rc; > + > +classdev_fail: > + for (i = priv->num_leds - 2; i > 0; i--) > + powernv_led_delete(&priv->powernv_leds[i]); > + > + return rc; > +} > + > +/* > + * We want to populate LED device for each LED type. Hence we > + * have to calculate count explicitly. > + */ > +static int powernv_leds_count(struct device_node *led_node) > +{ > + const char *cur = NULL; > + int num_leds = 0; > + struct property *p; > + struct device_node *np; > + > + 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) > + num_leds++; > + } > + > + return num_leds; > +} > + > +/* Platform driver probe */ > +static int powernv_led_probe(struct platform_device *pdev) > +{ > + int num_leds; > + struct device_node *led_node; > + struct powernv_leds_priv *priv; > + > + led_node = of_find_node_by_path("/ibm,opal/led"); > + if (!led_node) { > + dev_err(&pdev->dev, > + "%s: LED parent device node not found\n", __func__); > + return -EINVAL; > + } > + > + num_leds = powernv_leds_count(led_node); > + if (num_leds <= 0) { > + dev_err(&pdev->dev, > + "%s: No location code found under LED node\n", > + __func__); > + return -EINVAL; > + } > + > + priv = devm_kzalloc(&pdev->dev, > + sizeof_powernv_leds_priv(num_leds), > + GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + > + return powernv_led_classdev(pdev, led_node, priv, num_leds); > +} > + > +/* Platform driver remove */ > +static int powernv_led_remove(struct platform_device *pdev) > +{ > + int i; > + struct powernv_led_data *powernv_led; > + struct powernv_leds_priv *priv; > + > + /* Disable LED operation */ > + led_disabled = true; > + > + priv = platform_get_drvdata(pdev); > + > + for (i = 0; i < priv->num_leds; i++) { > + powernv_led = &priv->powernv_leds[i]; > + powernv_led_delete(powernv_led); > + flush_work(&powernv_led->work_led); > + } > + > + 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", > + .owner = THIS_MODULE, > + .of_match_table = powernv_led_match, > + }, > +}; > + > +module_platform_driver(powernv_led_driver); > + > +MODULE_LICENSE("GPL"); > +MODULE_DESCRIPTION("PowerNV LED driver"); > +MODULE_AUTHOR("Vasant Hegde "); > > -- > To unsubscribe from this list: send the line "unsubscribe linux-leds" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- Best Regards, Jacek Anaszewski From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mailout3.w1.samsung.com (mailout3.w1.samsung.com [210.118.77.13]) (using TLSv1 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 721B31A0E1D for ; Fri, 1 May 2015 00:29:32 +1000 (AEST) Received: from eucpsbgm1.samsung.com (unknown [203.254.199.244]) by mailout3.w1.samsung.com (Oracle Communications Messaging Server 7.0.5.31.0 64bit (built May 5 2014)) with ESMTP id <0NNM005VXIX3E350@mailout3.w1.samsung.com> for linuxppc-dev@lists.ozlabs.org; Thu, 30 Apr 2015 15:29:27 +0100 (BST) Message-id: <55423C45.3070601@samsung.com> Date: Thu, 30 Apr 2015 16:29:25 +0200 From: Jacek Anaszewski MIME-version: 1.0 To: Vasant Hegde Subject: Re: [PATCH v4 3/3] leds/powernv: Add driver for PowerNV platform References: <20150428100535.26912.29607.stgit@localhost.localdomain> <20150428101008.26912.38735.stgit@localhost.localdomain> In-reply-to: <20150428101008.26912.38735.stgit@localhost.localdomain> Content-type: text/plain; charset=UTF-8; format=flowed Cc: stewart@linux.vnet.ibm.com, j.anaszewski81@gmail.com, cooloney@gmail.com, rpurdie@rpsys.net, linuxppc-dev@lists.ozlabs.org, linux-leds@vger.kernel.org, khandual@linux.vnet.ibm.com List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi Vasant, On 04/28/2015 12:10 PM, Vasant Hegde wrote: > This patch implements LED driver for PowerNV platform using the existing > generic LED class framework. > > PowerNV platform has below type of LEDs: > - System attention > Indicates there is a problem with the system that needs attention. > - Identify > Helps the user locate/identify a particular FRU or resource in the > system. > - Fault > Indicates there is a problem with the FRU or resource at the > location with which the indicator is associated. > > We register classdev structures for all individual LEDs detected on the > system through LED specific device tree nodes. Device tree nodes specify > what all kind of LEDs present on the same location code. It registers > LED classdev structure for each of them. > > All the system LEDs can be found in the same regular path /sys/class/leds/. > We don't use LED colors. We use LED node and led-types property to form > LED classdev. Our LEDs have names in this format. > > : > > Any positive brightness value would turn on the LED and a zero value would > turn off the LED. The driver will return LED_FULL (255) for any turned on > LED and LED_OFF (0) for any turned off LED. > > As per the LED class framework, the 'brightness_set' function should not > sleep. Hence these functions have been implemented through global work > queue tasks which might sleep on OPAL async call completion. > > The platform level implementation of LED get and set state has been achieved > through OPAL calls. These calls are made available for the driver by > exporting from architecture specific codes. > > Signed-off-by: Vasant Hegde > Signed-off-by: Anshuman Khandual > Acked-by: Stewart Smith > Tested-by: Stewart Smith > > --- > Changes in v4: > - s/u64/__be64/g for big endian data we get from firmware > - Addressed review comments from Jacek. Major once are: > Removed list in powernv_led_data structure > s/kzalloc/devm_kzalloc/ > Removed compatible property from documentation > s/powernv_led_set_queue/powernv_brightness_set/ > - Removed LED specific brightness_set/get function. Instead this version > uses single function to queue all LED set/get requests. Later we use > LED name to detect LED type and value. > - Removed hardcoded LED type used in previous version. Instead we use > led-types property to form LED classdev. > > > Changes in v3: > - Addressed review comments from Jacek. Major once are: > Replaced spin lock and mutex and removed redundant structures > Replaced pr_* with dev_* > Moved OPAL platform sepcific part to separate patch > Moved repteated code to common function > Added device tree documentation for LEDs > > > Changes in v2: > - Added System Attention indicator support > - Moved common code to powernv_led_set_queue() > > > .../devicetree/bindings/leds/leds-powernv.txt | 29 + > drivers/leds/Kconfig | 11 > drivers/leds/Makefile | 1 > drivers/leds/leds-powernv.c | 472 ++++++++++++++++++++ > 4 files changed, 513 insertions(+) > create mode 100644 Documentation/devicetree/bindings/leds/leds-powernv.txt > create mode 100644 drivers/leds/leds-powernv.c > > diff --git a/Documentation/devicetree/bindings/leds/leds-powernv.txt b/Documentation/devicetree/bindings/leds/leds-powernv.txt > new file mode 100644 > index 0000000..6bb0e7e > --- /dev/null > +++ b/Documentation/devicetree/bindings/leds/leds-powernv.txt > @@ -0,0 +1,29 @@ > +Device Tree binding for LEDs on IBM Power Systems > +------------------------------------------------- > + > +The 'led' node under '/ibm,opal' lists service indicators available in the > +system and their capabilities. > + > +led { > + compatible = "ibm,opal-v3-led"; > + phandle = <0x1000006b>; > + linux,phandle = <0x1000006b>; > + led-mode = "lightpath"; > + > + U78C9.001.RST0027-P1-C1 { > + led-types = "identify", "fault"; > + led-loc = "descendent"; > + phandle = <0x1000006f>; > + linux,phandle = <0x1000006f>; > + }; > + ... > + ... > +}; > + > +Each node under 'led' node describes location code of FRU/Enclosure. > + > +The properties under each node: > + > + led-types : Supported LED types (attention/identify/fault). > + > + led-loc : enclosure/descendent(FRU) location code. DT documentation it usually constructed so that properties are described in the beginning and the file ends with an example. Also last time I mistakenly requested to remove description of compatible property, but it should also be present here and the entry should described it in detail, like: - compatible : Should be "ibm,opal-v3-led". Please refer to the other bindings, I will express my opinion on the LED part after powerpc maintainer will ack DT bindings. > diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig > index 25b320d..2ea0849 100644 > --- a/drivers/leds/Kconfig > +++ b/drivers/leds/Kconfig > @@ -508,6 +508,17 @@ 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 cbba921..604ffc9 100644 > --- a/drivers/leds/Makefile > +++ b/drivers/leds/Makefile > @@ -58,6 +58,7 @@ obj-$(CONFIG_LEDS_BLINKM) += leds-blinkm.o > obj-$(CONFIG_LEDS_SYSCON) += leds-syscon.o > obj-$(CONFIG_LEDS_VERSATILE) += leds-versatile.o > obj-$(CONFIG_LEDS_MENF21BMC) += leds-menf21bmc.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 0000000..bea46fd > --- /dev/null > +++ b/drivers/leds/leds-powernv.c > @@ -0,0 +1,472 @@ > +/* > + * PowerNV LED Driver > + * > + * Copyright IBM Corp. 2015 > + * > + * Author: Vasant Hegde > + * Author: Anshuman Khandual > + * > + * 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 > +#include > +#include > +#include > +#include > +#include > + > +#include > + > +/* > + * LED support for PowerNV platform: > + * - Identify and fault LEDs are overloaded (meaning we use single LED to > + * represent both state). > + * Physical LED state : off = normal, blinking = identify, solid = fault > + * Hardware takes care of maintaining/changing LED state. From user point > + * of view these are two different LEDs. Hence we use separate led > + * classsdev for identify and fault. > + * - 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. > + */ > + > +/* Disable LED support in unload path */ > +static bool led_disabled; > + > +/* 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}, > +}; > + > +/* > + * LED set routines have been implemented as work queue tasks scheduled > + * on the global work queue. Individual task calls OPAL interface to set > + * the LED state which might sleep for some time. > + */ > +struct powernv_led_data { > + struct led_classdev cdev; > + enum led_brightness value; /* Brightness value */ > + struct mutex lock; > + struct work_struct work_led; /* LED update workqueue */ > +}; > + > +struct powernv_leds_priv { > + int num_leds; > + struct powernv_led_data powernv_leds[]; > +}; > + > + > +static inline int sizeof_powernv_leds_priv(int num_leds) > +{ > + return sizeof(struct powernv_leds_priv) + > + (sizeof(struct powernv_led_data) * num_leds); > +} > + > +/* Returns OPAL_SLOT_LED_TYPE_* for given led type string */ > +static int powernv_get_led_type(struct led_classdev *led_cdev) > +{ > + char *desc; > + int i; > + > + desc = strstr(led_cdev->name, ":"); > + if (!desc) > + return -1; > + desc++; > + if (!desc) > + return -1; > + > + for (i = 0; i < ARRAY_SIZE(led_type_map); i++) > + if (!strcmp(led_type_map[i].desc, desc)) > + return led_type_map[i].type; > + > + return -1; > +} > + > +/* This function gets LED location code for given LED classdev */ > +static char *powernv_get_location_code(struct led_classdev *led_cdev) > +{ > + char *loc_code; > + char *colon; > + > + /* Location code of the LED */ > + loc_code = kasprintf(GFP_KERNEL, "%s", led_cdev->name); > + if (!loc_code) { > + dev_err(led_cdev->dev, > + "%s: Memory allocation failed\n", __func__); > + return NULL; > + } > + > + colon = strstr(loc_code, ":"); > + if (!colon) { > + kfree(loc_code); > + return NULL; > + } > + > + *colon = '\0'; > + return loc_code; > +} > + > +/* > + * 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 led_classdev *led_cdev, > + enum led_brightness value) > +{ > + char *loc_code; > + int rc, token, led_type; > + u64 led_mask, led_value = 0; > + __be64 max_led_type; > + struct opal_msg msg; > + > + led_type = powernv_get_led_type(led_cdev); > + if (led_type == -1) > + return; > + > + loc_code = powernv_get_location_code(led_cdev); > + if (!loc_code) > + return; > + > + /* Prepare for the OPAL call */ > + max_led_type = cpu_to_be64(OPAL_SLOT_LED_TYPE_MAX); > + led_mask = OPAL_SLOT_LED_STATE_ON << 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(led_cdev->dev, > + "%s: Couldn't get OPAL async token\n", > + __func__); > + goto out_loc; > + } > + > + rc = opal_leds_set_ind(token, loc_code, > + led_mask, led_value, &max_led_type); > + if (rc != OPAL_ASYNC_COMPLETION) { > + dev_err(led_cdev->dev, > + "%s: OPAL set LED call failed for %s [rc=%d]\n", > + __func__, loc_code, rc); > + goto out_token; > + } > + > + rc = opal_async_wait_response(token, &msg); > + if (rc) { > + dev_err(led_cdev->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(led_cdev->dev, > + "%s : OAPL async call returned failed [rc=%d]\n", > + __func__, rc); > + > +out_token: > + opal_async_release_token(token); > + > +out_loc: > + kfree(loc_code); > +} > + > +/* > + * This function fetches the LED state for a given LED type for > + * mentioned LED classdev structure. > + */ > +static enum led_brightness powernv_led_get(struct led_classdev *led_cdev) > +{ > + char *loc_code; > + int rc, led_type; > + __be64 led_mask, led_value, max_led_type; > + > + led_type = powernv_get_led_type(led_cdev); > + if (led_type == -1) > + return LED_OFF; > + > + loc_code = powernv_get_location_code(led_cdev); > + if (!loc_code) > + return LED_OFF; > + > + /* Fetch all LED status */ > + led_mask = cpu_to_be64(0); > + led_value = cpu_to_be64(0); > + max_led_type = cpu_to_be64(OPAL_SLOT_LED_TYPE_MAX); > + > + rc = opal_leds_get_ind(loc_code, &led_mask, &led_value, &max_led_type); > + if (rc != OPAL_SUCCESS && rc != OPAL_PARTIAL) { > + dev_err(led_cdev->dev, > + "%s: OPAL get led call failed [rc=%d]\n", > + __func__, rc); > + goto led_fail; > + } > + > + led_mask = be64_to_cpu(led_mask); > + led_value = be64_to_cpu(led_value); > + > + /* LED status available */ > + if (!((led_mask >> led_type) & OPAL_SLOT_LED_STATE_ON)) { > + dev_err(led_cdev->dev, > + "%s: LED status not available for %s\n", > + __func__, led_cdev->name); > + goto led_fail; > + } > + > + /* LED status value */ > + if ((led_value >> led_type) & OPAL_SLOT_LED_STATE_ON) { > + kfree(loc_code); > + return LED_FULL; > + } > + > +led_fail: > + kfree(loc_code); > + return LED_OFF; > +} > + > +/* Execute LED set task for given led classdev */ > +static void powernv_deferred_led_set(struct work_struct *work) > +{ > + struct powernv_led_data *powernv_led = > + container_of(work, struct powernv_led_data, work_led); > + > + mutex_lock(&powernv_led->lock); > + powernv_led_set(&powernv_led->cdev, powernv_led->value); > + mutex_unlock(&powernv_led->lock); > +} > + > +/* > + * 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); > + > + /* Do not modify LED in unload path */ > + if (led_disabled) > + return; > + > + /* Prepare the request */ > + powernv_led->value = value; > + > + /* Schedule the new task */ > + schedule_work(&powernv_led->work_led); > +} > + > +/* LED classdev 'brightness_get' function */ > +static enum led_brightness > +powernv_brightness_get(struct led_classdev *led_cdev) > +{ > + return powernv_led_get(led_cdev); > +} > + > + > +/* > + * 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_name, const char *led_type_desc) > +{ > + int rc; > + > + /* Create the name for classdev */ > + powernv_led->cdev.name = kasprintf(GFP_KERNEL, "%s:%s", > + led_name, led_type_desc); > + if (!powernv_led->cdev.name) { > + dev_err(dev, > + "%s: Memory allocation failed for classdev name\n", > + __func__); > + return -ENOMEM; > + } > + > + /* Make sure LED type is supported */ > + if (powernv_get_led_type(&powernv_led->cdev) == -1) { > + kfree(powernv_led->cdev.name); > + return -EINVAL; > + } > + > + 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; > + > + mutex_init(&powernv_led->lock); > + INIT_WORK(&powernv_led->work_led, powernv_deferred_led_set); > + > + /* Register the classdev */ > + rc = led_classdev_register(dev, &powernv_led->cdev); > + if (rc) { > + dev_err(dev, "%s: Classdev registration failed for %s\n", > + __func__, powernv_led->cdev.name); > + kfree(powernv_led->cdev.name); > + } > + > + return rc; > +} > + > +/* Unregister classdev structure for any given LED */ > +static void powernv_led_delete(struct powernv_led_data *powernv_led) > +{ > + led_classdev_unregister(&powernv_led->cdev); > +} > + > +/* 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_leds_priv *priv, int num_leds) > +{ > + const char *cur = NULL; > + int i, 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 = &priv->powernv_leds[priv->num_leds++]; > + if (priv->num_leds > num_leds) { > + rc = -ENOMEM; > + goto classdev_fail; > + } > + rc = powernv_led_create(dev, > + powernv_led, np->name, cur); > + if (rc) > + goto classdev_fail; > + } /* while end */ > + } > + > + platform_set_drvdata(pdev, priv); > + return rc; > + > +classdev_fail: > + for (i = priv->num_leds - 2; i > 0; i--) > + powernv_led_delete(&priv->powernv_leds[i]); > + > + return rc; > +} > + > +/* > + * We want to populate LED device for each LED type. Hence we > + * have to calculate count explicitly. > + */ > +static int powernv_leds_count(struct device_node *led_node) > +{ > + const char *cur = NULL; > + int num_leds = 0; > + struct property *p; > + struct device_node *np; > + > + 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) > + num_leds++; > + } > + > + return num_leds; > +} > + > +/* Platform driver probe */ > +static int powernv_led_probe(struct platform_device *pdev) > +{ > + int num_leds; > + struct device_node *led_node; > + struct powernv_leds_priv *priv; > + > + led_node = of_find_node_by_path("/ibm,opal/led"); > + if (!led_node) { > + dev_err(&pdev->dev, > + "%s: LED parent device node not found\n", __func__); > + return -EINVAL; > + } > + > + num_leds = powernv_leds_count(led_node); > + if (num_leds <= 0) { > + dev_err(&pdev->dev, > + "%s: No location code found under LED node\n", > + __func__); > + return -EINVAL; > + } > + > + priv = devm_kzalloc(&pdev->dev, > + sizeof_powernv_leds_priv(num_leds), > + GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + > + return powernv_led_classdev(pdev, led_node, priv, num_leds); > +} > + > +/* Platform driver remove */ > +static int powernv_led_remove(struct platform_device *pdev) > +{ > + int i; > + struct powernv_led_data *powernv_led; > + struct powernv_leds_priv *priv; > + > + /* Disable LED operation */ > + led_disabled = true; > + > + priv = platform_get_drvdata(pdev); > + > + for (i = 0; i < priv->num_leds; i++) { > + powernv_led = &priv->powernv_leds[i]; > + powernv_led_delete(powernv_led); > + flush_work(&powernv_led->work_led); > + } > + > + 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", > + .owner = THIS_MODULE, > + .of_match_table = powernv_led_match, > + }, > +}; > + > +module_platform_driver(powernv_led_driver); > + > +MODULE_LICENSE("GPL"); > +MODULE_DESCRIPTION("PowerNV LED driver"); > +MODULE_AUTHOR("Vasant Hegde "); > > -- > To unsubscribe from this list: send the line "unsubscribe linux-leds" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- Best Regards, Jacek Anaszewski