From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-x234.google.com (mail-wi0-x234.google.com [IPv6:2a00:1450:400c:c05::234]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id BFE311A0186 for ; Thu, 23 Jul 2015 17:57:17 +1000 (AEST) Received: by wicgb10 with SMTP id gb10so130777529wic.1 for ; Thu, 23 Jul 2015 00:57:14 -0700 (PDT) Message-ID: <55B09DFB.2080108@gmail.com> Date: Thu, 23 Jul 2015 09:55:39 +0200 From: Jacek Anaszewski MIME-Version: 1.0 To: Vasant Hegde , linux-leds@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, j.anaszewski@samsung.com CC: stewart@linux.vnet.ibm.com, arnd@arndb.de, j.anaszewski81@gmail.com, cooloney@gmail.com, rpurdie@rpsys.net, khandual@linux.vnet.ibm.com, mpe@ellerman.id.au, benh@kernel.crashing.org Subject: Re: [PATCH v7 3/3] leds/powernv: Add driver for PowerNV platform References: <1437576767-28496-1-git-send-email-hegdevasant@linux.vnet.ibm.com> <1437576767-28496-4-git-send-email-hegdevasant@linux.vnet.ibm.com> In-Reply-To: <1437576767-28496-4-git-send-email-hegdevasant@linux.vnet.ibm.com> Content-Type: text/plain; charset=windows-1252; format=flowed List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi Vasant, Thanks for the update. On 22.07.2015 16:52, 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 > --- > .../devicetree/bindings/leds/leds-powernv.txt | 26 ++ > drivers/leds/Kconfig | 11 + > drivers/leds/Makefile | 1 + > drivers/leds/leds-powernv.c | 342 +++++++++++++++++++++ > 4 files changed, 380 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..6665569 > --- /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 9ad35f7..f218cc3a 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 8d6a24a..6a943d1 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 0000000..9e70291 > --- /dev/null > +++ b/drivers/leds/leds-powernv.c > @@ -0,0 +1,342 @@ > +/* > + * 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 > + > +/* > + * 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. > + */ > +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}, > +}; > + > +/* PowerNV LED data */ > +struct powernv_led_data { > + struct led_classdev cdev; > + char *loc_code; /* LED location code */ > + int led_type; /* OPAL_SLOT_LED_TYPE_* */ > + enum led_brightness value; /* Brightness value */ You don't need 'value' as brightness value is already stored in cdev.brightness. > + > + __be64 *max_led_type; /* Max supported LED type */ > + struct mutex *lock; /* glabal lock */ > +}; > + > + > +/* 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) > +{ > + int rc, token; > + u64 led_mask, led_value = 0; > + __be64 max_type; > + struct opal_msg msg; > + struct device *dev = powernv_led->cdev.dev; > + > + /* Prepare for the OPAL call */ > + max_type = *(powernv_led->max_led_type); > + led_mask = OPAL_SLOT_LED_STATE_ON << powernv_led->led_type; > + if (powernv_led->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; > + > + /* Fetch all LED status */ > + mask = cpu_to_be64(0); > + value = cpu_to_be64(0); > + max_type = *(powernv_led->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); > + > + /* Do not modify LED in unload path */ > + if (led_disabled) > + return; > + > + /* Prepare the request */ > + powernv_led->value = value; > + > + return powernv_led_set(powernv_led); Isn't mutex_lock/unlock missing here? > +} > + > +/* 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, > + __be64 *max_led_type, struct mutex *lock) > +{ > + 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->loc_code = (char *)np->name; > + powernv_led->max_led_type = max_led_type; > + powernv_led->lock = lock; > + > + 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) > +{ > + __be64 *max_led_type; > + struct mutex *lock; > + struct device_node *led_node; > + 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; > + } > + > + lock = devm_kzalloc(dev, sizeof(*lock), GFP_KERNEL); > + if (!lock) > + return -ENOMEM; > + > + max_led_type = devm_kzalloc(dev, sizeof(*max_led_type), GFP_KERNEL); > + if (!max_led_type) > + return -ENOMEM; > + > + mutex_init(lock); > + *max_led_type = cpu_to_be64(OPAL_SLOT_LED_TYPE_MAX); > + > + platform_set_drvdata(pdev, lock); Setting only lock as drvdata looks odd to me and I haven't noticed anyone doing that. I'd prefer to put lock, led_disabled and max_led_type in a common struct and set it as drvdata. I know that I accepted this design, but I didn't take into account these details. > + return powernv_led_classdev(pdev, led_node, max_led_type, lock); > +} > + > +/* Platform driver remove */ > +static int powernv_led_remove(struct platform_device *pdev) > +{ > + struct mutex *lock = platform_get_drvdata(pdev); > + > + /* Disable LED operation */ > + led_disabled = true; > + > + mutex_destroy(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", > + .owner = THIS_MODULE, > + .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 "); > -- Best Regards, Jacek Anaszewski