[PATCH v4 0/3] LED interface for PowerNV platform

[PATCH v4 0/3] LED interface for PowerNV platform

[Vasant Hegde]

The following series implements LED driver for PowerNV platform.

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.

On PowerNV (Non Virtualized) platform OPAL firmware provides LED information
to host via device tree (location code and LED type). During init we check
for 'ibm,opal/led' node in device tree to enable LED driver. And we use
OPAL API's to get/set LEDs.

Note that on PowerNV platform firmware can activate fault LED, if it can isolate
the problem. Also one can modify the LEDs using service processor interface. None
of these involes kernel. Hence we retain LED state in unload path.

Sample LED device tree output:
------------------------------
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>;
	};
	...
	...
    }

Sample sysfs output:
--------------------
.
├── U78CB.001.WZS008R-A1:fault
│   ├── brightness
│   ├── device -> ../../../opal_led
│   ├── max_brightness
│   ├── power
│   │   ├── async
│   │   ├── autosuspend_delay_ms
│   │   ├── control
│   │   ├── runtime_active_kids
│   │   ├── runtime_active_time
│   │   ├── runtime_enabled
│   │   ├── runtime_status
│   │   ├── runtime_suspended_time
│   │   └── runtime_usage
│   ├── subsystem -> ../../../../../class/leds
│   ├── trigger
│   └── uevent
├── U78CB.001.WZS008R-A1:identify
│   ├── brightness
│   ├── device -> ../../../opal_led
│   ├── max_brightness
│   ├── power
│   │   ├── async
│   │   ├── autosuspend_delay_ms
│   │   ├── control
│   │   ├── runtime_active_kids
│   │   ├── runtime_active_time
│   │   ├── runtime_enabled
│   │   ├── runtime_status
│   │   ├── runtime_suspended_time
│   │   └── runtime_usage
│   ├── subsystem -> ../../../../../class/leds
│   ├── trigger
│   └── uevent
....
....
....

patch 1/2: PowerNV architecture specific code. This adds necessary
           OPAL APIs.
patch 2/2: Create LED platform device and export OPAL symbols
patch 3/3: Actual LED driver implemenation for PowerNV platform.

This patchset is based on top of mpe's next branch:
  https://git.kernel.org/cgit/linux/kernel/git/mpe/linux.git/log/?h=next

Previous patchset:
  v3: https://lists.ozlabs.org/pipermail/linuxppc-dev/2015-April/127702.html
  v2: https://lists.ozlabs.org/pipermail/linuxppc-dev/2015-March/126301.html
  v1: https://lists.ozlabs.org/pipermail/linuxppc-dev/2015-March/125705.html

Changes in v4:
  - Updated macros to reflect platform.
  - 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:
  - Rebased patches on top of mpe's next branch
    https://git.kernel.org/cgit/linux/kernel/git/mpe/linux.git/log/?h=next
  - Added System Attention Indicator support
  - Removed redundant code in leds-powernv.c file


---

Anshuman Khandual (1):
      powerpc/powernv: Add OPAL interfaces for accessing and modifying system LED states

Vasant Hegde (2):
      powerpc/powernv: Create LED platform device
      leds/powernv: Add driver for PowerNV platform


 .../devicetree/bindings/leds/leds-powernv.txt      |   29 +
 arch/powerpc/include/asm/opal-api.h                |   29 +
 arch/powerpc/include/asm/opal.h                    |    5 
 arch/powerpc/platforms/powernv/opal-wrappers.S     |    2 
 arch/powerpc/platforms/powernv/opal.c              |   12 -
 drivers/leds/Kconfig                               |   11 
 drivers/leds/Makefile                              |    1 
 drivers/leds/leds-powernv.c                        |  472 ++++++++++++++++++++
 8 files changed, 559 insertions(+), 2 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/leds/leds-powernv.txt
 create mode 100644 drivers/leds/leds-powernv.c

--
Vasant

[PATCH v4 1/3] powerpc/powernv: Add OPAL interfaces for accessing and modifying system LED states

[Vasant Hegde]

From: Anshuman Khandual <khandual@linux.vnet.ibm.com>

This patch registers the following two new OPAL interfaces calls
for the platform LED subsystem. With the help of these new OPAL calls,
the kernel will be able to get or set the state of various individual
LEDs on the system at any given location code which is passed through
the LED specific device tree nodes.

	(1) OPAL_LEDS_GET_INDICATOR     opal_leds_get_ind
	(2) OPAL_LEDS_SET_INDICATOR     opal_leds_set_ind

Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Acked-by: Stewart Smith <stewart@linux.vnet.ibm.com>
Tested-by: Stewart Smith <stewart@linux.vnet.ibm.com>

---
Changes in v4:
  - Updated macros to reflect platform.

 arch/powerpc/include/asm/opal-api.h            |   29 +++++++++++++++++++++++-
 arch/powerpc/include/asm/opal.h                |    5 ++++
 arch/powerpc/platforms/powernv/opal-wrappers.S |    2 ++
 3 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/opal-api.h b/arch/powerpc/include/asm/opal-api.h
index 0321a90..ff85397 100644
--- a/arch/powerpc/include/asm/opal-api.h
+++ b/arch/powerpc/include/asm/opal-api.h
@@ -153,7 +153,9 @@
 #define OPAL_FLASH_READ				110
 #define OPAL_FLASH_WRITE			111
 #define OPAL_FLASH_ERASE			112
-#define OPAL_LAST				112
+#define OPAL_LEDS_GET_INDICATOR			114
+#define OPAL_LEDS_SET_INDICATOR			115
+#define OPAL_LAST				115
 
 /* Device tree flags */
 
@@ -730,6 +732,31 @@ struct opal_i2c_request {
 	__be64 buffer_ra;		/* Buffer real address */
 };
 
+/* LED Mode */
+#define POWERNV_LED_MODE_LIGHT_PATH	"lightpath"
+#define POWERNV_LED_MODE_GUIDING_LIGHT	"guidinglight"
+
+/* LED type */
+#define POWERNV_LED_TYPE_IDENTIFY	"identify"
+#define POWERNV_LED_TYPE_FAULT		"fault"
+#define POWERNV_LED_TYPE_ATTENTION	"attention"
+
+/* LED location */
+#define POWERNV_LED_LOC_ENCLOSURE	"enclosure"
+#define POWERNV_LED_LOC_DESCENDENT	"descendent"
+
+enum OpalSlotLedType {
+	OPAL_SLOT_LED_TYPE_ID = 0,	/* IDENTIFY LED */
+	OPAL_SLOT_LED_TYPE_FAULT = 1,	/* FAULT LED */
+	OPAL_SLOT_LED_TYPE_ATTN = 2,	/* System Attention LED */
+	OPAL_SLOT_LED_TYPE_MAX = 3
+};
+
+enum OpalSlotLedState {
+	OPAL_SLOT_LED_STATE_OFF = 0,	/* LED is OFF */
+	OPAL_SLOT_LED_STATE_ON = 1	/* LED is ON */
+};
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* __OPAL_API_H */
diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
index 042af1a..e06dc7e 100644
--- a/arch/powerpc/include/asm/opal.h
+++ b/arch/powerpc/include/asm/opal.h
@@ -193,6 +193,11 @@ int64_t opal_ipmi_recv(uint64_t interface, struct opal_ipmi_msg *msg,
 		uint64_t *msg_len);
 int64_t opal_i2c_request(uint64_t async_token, uint32_t bus_id,
 			 struct opal_i2c_request *oreq);
+int64_t opal_leds_get_ind(char *loc_code, u64 *led_mask,
+			  u64 *led_value, u64 *max_led_type);
+int64_t opal_leds_set_ind(uint64_t token, char *loc_code, const u64 led_mask,
+			  const u64 led_value, u64 *max_led_type);
+
 
 int64_t opal_flash_read(uint64_t id, uint64_t offset, uint64_t buf,
 		uint64_t size, uint64_t token);
diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S
index 4e74037..20d4da4 100644
--- a/arch/powerpc/platforms/powernv/opal-wrappers.S
+++ b/arch/powerpc/platforms/powernv/opal-wrappers.S
@@ -295,3 +295,5 @@ OPAL_CALL(opal_i2c_request,			OPAL_I2C_REQUEST);
 OPAL_CALL(opal_flash_read,			OPAL_FLASH_READ);
 OPAL_CALL(opal_flash_write,			OPAL_FLASH_WRITE);
 OPAL_CALL(opal_flash_erase,			OPAL_FLASH_ERASE);
+OPAL_CALL(opal_leds_get_ind,			OPAL_LEDS_GET_INDICATOR);
+OPAL_CALL(opal_leds_set_ind,			OPAL_LEDS_SET_INDICATOR);

[PATCH v4 2/3] powerpc/powernv: Create LED platform device

[Vasant Hegde]

This patch adds paltform devices for leds. Also export LED related
OPAL API's so that led driver can use these APIs.

Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
---
 arch/powerpc/platforms/powernv/opal.c |   12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index 2241565..b1951aa 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -784,7 +784,7 @@ static void opal_init_heartbeat(void)
 
 static int __init opal_init(void)
 {
-	struct device_node *np, *consoles;
+	struct device_node *np, *consoles, *led;
 	int rc;
 
 	opal_node = of_find_node_by_path("/ibm,opal");
@@ -813,6 +813,13 @@ static int __init opal_init(void)
 	/* Setup a heatbeat thread if requested by OPAL */
 	opal_init_heartbeat();
 
+	/* Create led platform devices */
+	led = of_find_node_by_path("/ibm,opal/led");
+	if (led) {
+		of_platform_device_create(led, "opal_led", NULL);
+		of_node_put(led);
+	}
+
 	/* Find all OPAL interrupts and request them */
 	opal_irq_init(opal_node);
 
@@ -970,3 +977,6 @@ EXPORT_SYMBOL_GPL(opal_rtc_write);
 EXPORT_SYMBOL_GPL(opal_tpo_read);
 EXPORT_SYMBOL_GPL(opal_tpo_write);
 EXPORT_SYMBOL_GPL(opal_i2c_request);
+/* Export these symbols for PowerNV LED class driver */
+EXPORT_SYMBOL_GPL(opal_leds_get_ind);
+EXPORT_SYMBOL_GPL(opal_leds_set_ind);

[PATCH v4 3/3] leds/powernv: Add driver for PowerNV platform

[Vasant Hegde]

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.

        <location_code>:<attention|identify|fault>

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 <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Acked-by: Stewart Smith <stewart@linux.vnet.ibm.com>
Tested-by: Stewart Smith <stewart@linux.vnet.ibm.com>

---
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.
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 <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>
+
+/*
+ * 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 <hegdevasant@linux.vnet.ibm.com>");

Re: [PATCH v4 3/3] leds/powernv: Add driver for PowerNV platform

[Arnd Bergmann]

On Tuesday 28 April 2015 15:40:35 Vasant Hegde wrote:
> +++ 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>;
> +       };
> +       ...
> +       ...
> +};

We normally don't list the 'phandle' or 'linux,phandle' properties in the binding
description.

> +
> +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.
> 

Could you use the standard 'label' property for this?

	Arnd

Re: [PATCH v4 3/3] leds/powernv: Add driver for PowerNV platform

[Jacek Anaszewski]

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.
>
>          <location_code>:<attention|identify|fault>
>
> 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 <hegdevasant@linux.vnet.ibm.com>
> Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
> Acked-by: Stewart Smith <stewart@linux.vnet.ibm.com>
> Tested-by: Stewart Smith <stewart@linux.vnet.ibm.com>
>
> ---
> 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 <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>
> +
> +/*
> + * 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 <hegdevasant@linux.vnet.ibm.com>");
>
> --
> 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

Re: [PATCH v4 3/3] leds/powernv: Add driver for PowerNV platform

[Vasant Hegde]

On 04/28/2015 03:48 PM, Arnd Bergmann wrote:
> On Tuesday 28 April 2015 15:40:35 Vasant Hegde wrote:
>> +++ 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>;
>> +       };
>> +       ...
>> +       ...
>> +};

Arnd,

  Thanks for the review.

> 
> We normally don't list the 'phandle' or 'linux,phandle' properties in the binding
> description.
> 

Sure. .Will fix.


>> +
>> +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.
>>
> 
> Could you use the standard 'label' property for this?

This was discussed earlier [1] and agreed to use led-types property here..

[1] https://lists.ozlabs.org/pipermail/linuxppc-dev/2015-March/126301.html

-Vasant

Re: [PATCH v4 3/3] leds/powernv: Add driver for PowerNV platform

[Vasant Hegde]

On 04/30/2015 07:59 PM, Jacek Anaszewski wrote:
> Hi Vasant,
> 

Hi  Jacek,

.../...

>> 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".

That's fine. I will fix it in v5.

> 
> Please refer to the other bindings,
> 
> I will express my opinion on the LED part after powerpc maintainer
> will ack DT bindings.
> 

Sure..

@Ben/Michael,
  Can you please review/ack this patchset?

-Vasant

Re: [PATCH v4 0/3] LED interface for PowerNV platform

[Vasant Hegde]

On 04/28/2015 03:39 PM, Vasant Hegde wrote:
> The following series implements LED driver for PowerNV platform.

Ben, Michael,

Can you please review/ACK this patchset?

-Vasant

> 
> 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.
> 
> On PowerNV (Non Virtualized) platform OPAL firmware provides LED information
> to host via device tree (location code and LED type). During init we check
> for 'ibm,opal/led' node in device tree to enable LED driver. And we use
> OPAL API's to get/set LEDs.
> 
> Note that on PowerNV platform firmware can activate fault LED, if it can isolate
> the problem. Also one can modify the LEDs using service processor interface. None
> of these involes kernel. Hence we retain LED state in unload path.
> 
> Sample LED device tree output:
> ------------------------------
> 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>;
> 	};
> 	...
> 	...
>     }
> 
> Sample sysfs output:
> --------------------
> .
> ├── U78CB.001.WZS008R-A1:fault
> │   ├── brightness
> │   ├── device -> ../../../opal_led
> │   ├── max_brightness
> │   ├── power
> │   │   ├── async
> │   │   ├── autosuspend_delay_ms
> │   │   ├── control
> │   │   ├── runtime_active_kids
> │   │   ├── runtime_active_time
> │   │   ├── runtime_enabled
> │   │   ├── runtime_status
> │   │   ├── runtime_suspended_time
> │   │   └── runtime_usage
> │   ├── subsystem -> ../../../../../class/leds
> │   ├── trigger
> │   └── uevent
> ├── U78CB.001.WZS008R-A1:identify
> │   ├── brightness
> │   ├── device -> ../../../opal_led
> │   ├── max_brightness
> │   ├── power
> │   │   ├── async
> │   │   ├── autosuspend_delay_ms
> │   │   ├── control
> │   │   ├── runtime_active_kids
> │   │   ├── runtime_active_time
> │   │   ├── runtime_enabled
> │   │   ├── runtime_status
> │   │   ├── runtime_suspended_time
> │   │   └── runtime_usage
> │   ├── subsystem -> ../../../../../class/leds
> │   ├── trigger
> │   └── uevent
> ....
> ....
> ....
> 
> patch 1/2: PowerNV architecture specific code. This adds necessary
>            OPAL APIs.
> patch 2/2: Create LED platform device and export OPAL symbols
> patch 3/3: Actual LED driver implemenation for PowerNV platform.
> 
> This patchset is based on top of mpe's next branch:
>   https://git.kernel.org/cgit/linux/kernel/git/mpe/linux.git/log/?h=next
> 
> Previous patchset:
>   v3: https://lists.ozlabs.org/pipermail/linuxppc-dev/2015-April/127702.html
>   v2: https://lists.ozlabs.org/pipermail/linuxppc-dev/2015-March/126301.html
>   v1: https://lists.ozlabs.org/pipermail/linuxppc-dev/2015-March/125705.html
> 
> Changes in v4:
>   - Updated macros to reflect platform.
>   - 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:
>   - Rebased patches on top of mpe's next branch
>     https://git.kernel.org/cgit/linux/kernel/git/mpe/linux.git/log/?h=next
>   - Added System Attention Indicator support
>   - Removed redundant code in leds-powernv.c file
> 
> 
> ---
> 
> Anshuman Khandual (1):
>       powerpc/powernv: Add OPAL interfaces for accessing and modifying system LED states
> 
> Vasant Hegde (2):
>       powerpc/powernv: Create LED platform device
>       leds/powernv: Add driver for PowerNV platform
> 
> 
>  .../devicetree/bindings/leds/leds-powernv.txt      |   29 +
>  arch/powerpc/include/asm/opal-api.h                |   29 +
>  arch/powerpc/include/asm/opal.h                    |    5 
>  arch/powerpc/platforms/powernv/opal-wrappers.S     |    2 
>  arch/powerpc/platforms/powernv/opal.c              |   12 -
>  drivers/leds/Kconfig                               |   11 
>  drivers/leds/Makefile                              |    1 
>  drivers/leds/leds-powernv.c                        |  472 ++++++++++++++++++++
>  8 files changed, 559 insertions(+), 2 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/leds/leds-powernv.txt
>  create mode 100644 drivers/leds/leds-powernv.c
> 
> --
> Vasant
> 
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@lists.ozlabs.org
> https://lists.ozlabs.org/listinfo/linuxppc-dev
> 

Re: [PATCH v4 0/3] LED interface for PowerNV platform

[Jacek Anaszewski]

On 06/11/2015 08:33 AM, Vasant Hegde wrote:
> On 04/28/2015 03:39 PM, Vasant Hegde wrote:
>> The following series implements LED driver for PowerNV platform.
>
> Ben, Michael,
>
> Can you please review/ACK this patchset?

Yeah, we are waiting for ppc maintainer's ack, also to clarify
DT related issues. Ben himself asked to wait for the ack in the
message [1]. We are waiting for almost two months now :)

[1] http://www.spinics.net/lists/linux-leds/msg03557.html

-- 
Best Regards,
Jacek Anaszewski

Re: [PATCH v4 1/3] powerpc/powernv: Add OPAL interfaces for accessing and modifying system LED states

[Benjamin Herrenschmidt]

On Tue, 2015-04-28 at 15:39 +0530, Vasant Hegde wrote:
> From: Anshuman Khandual <khandual@linux.vnet.ibm.com>
> 
> This patch registers the following two new OPAL interfaces calls
> for the platform LED subsystem. With the help of these new OPAL calls,
> the kernel will be able to get or set the state of various individual
> LEDs on the system at any given location code which is passed through
> the LED specific device tree nodes.
> 
> 	(1) OPAL_LEDS_GET_INDICATOR     opal_leds_get_ind
> 	(2) OPAL_LEDS_SET_INDICATOR     opal_leds_set_ind
> 
> Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
> Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
> Acked-by: Stewart Smith <stewart@linux.vnet.ibm.com>
> Tested-by: Stewart Smith <stewart@linux.vnet.ibm.com>

Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

> ---
> Changes in v4:
>   - Updated macros to reflect platform.
> 
>  arch/powerpc/include/asm/opal-api.h            |   29 +++++++++++++++++++++++-
>  arch/powerpc/include/asm/opal.h                |    5 ++++
>  arch/powerpc/platforms/powernv/opal-wrappers.S |    2 ++
>  3 files changed, 35 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/include/asm/opal-api.h b/arch/powerpc/include/asm/opal-api.h
> index 0321a90..ff85397 100644
> --- a/arch/powerpc/include/asm/opal-api.h
> +++ b/arch/powerpc/include/asm/opal-api.h
> @@ -153,7 +153,9 @@
>  #define OPAL_FLASH_READ				110
>  #define OPAL_FLASH_WRITE			111
>  #define OPAL_FLASH_ERASE			112
> -#define OPAL_LAST				112
> +#define OPAL_LEDS_GET_INDICATOR			114
> +#define OPAL_LEDS_SET_INDICATOR			115
> +#define OPAL_LAST				115
>  
>  /* Device tree flags */
>  
> @@ -730,6 +732,31 @@ struct opal_i2c_request {
>  	__be64 buffer_ra;		/* Buffer real address */
>  };
>  
> +/* LED Mode */
> +#define POWERNV_LED_MODE_LIGHT_PATH	"lightpath"
> +#define POWERNV_LED_MODE_GUIDING_LIGHT	"guidinglight"
> +
> +/* LED type */
> +#define POWERNV_LED_TYPE_IDENTIFY	"identify"
> +#define POWERNV_LED_TYPE_FAULT		"fault"
> +#define POWERNV_LED_TYPE_ATTENTION	"attention"
> +
> +/* LED location */
> +#define POWERNV_LED_LOC_ENCLOSURE	"enclosure"
> +#define POWERNV_LED_LOC_DESCENDENT	"descendent"
> +
> +enum OpalSlotLedType {
> +	OPAL_SLOT_LED_TYPE_ID = 0,	/* IDENTIFY LED */
> +	OPAL_SLOT_LED_TYPE_FAULT = 1,	/* FAULT LED */
> +	OPAL_SLOT_LED_TYPE_ATTN = 2,	/* System Attention LED */
> +	OPAL_SLOT_LED_TYPE_MAX = 3
> +};
> +
> +enum OpalSlotLedState {
> +	OPAL_SLOT_LED_STATE_OFF = 0,	/* LED is OFF */
> +	OPAL_SLOT_LED_STATE_ON = 1	/* LED is ON */
> +};
> +
>  #endif /* __ASSEMBLY__ */
>  
>  #endif /* __OPAL_API_H */
> diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
> index 042af1a..e06dc7e 100644
> --- a/arch/powerpc/include/asm/opal.h
> +++ b/arch/powerpc/include/asm/opal.h
> @@ -193,6 +193,11 @@ int64_t opal_ipmi_recv(uint64_t interface, struct opal_ipmi_msg *msg,
>  		uint64_t *msg_len);
>  int64_t opal_i2c_request(uint64_t async_token, uint32_t bus_id,
>  			 struct opal_i2c_request *oreq);
> +int64_t opal_leds_get_ind(char *loc_code, u64 *led_mask,
> +			  u64 *led_value, u64 *max_led_type);
> +int64_t opal_leds_set_ind(uint64_t token, char *loc_code, const u64 led_mask,
> +			  const u64 led_value, u64 *max_led_type);
> +
>  
>  int64_t opal_flash_read(uint64_t id, uint64_t offset, uint64_t buf,
>  		uint64_t size, uint64_t token);
> diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S
> index 4e74037..20d4da4 100644
> --- a/arch/powerpc/platforms/powernv/opal-wrappers.S
> +++ b/arch/powerpc/platforms/powernv/opal-wrappers.S
> @@ -295,3 +295,5 @@ OPAL_CALL(opal_i2c_request,			OPAL_I2C_REQUEST);
>  OPAL_CALL(opal_flash_read,			OPAL_FLASH_READ);
>  OPAL_CALL(opal_flash_write,			OPAL_FLASH_WRITE);
>  OPAL_CALL(opal_flash_erase,			OPAL_FLASH_ERASE);
> +OPAL_CALL(opal_leds_get_ind,			OPAL_LEDS_GET_INDICATOR);
> +OPAL_CALL(opal_leds_set_ind,			OPAL_LEDS_SET_INDICATOR);

Re: [PATCH v4 2/3] powerpc/powernv: Create LED platform device

[Benjamin Herrenschmidt]

On Tue, 2015-04-28 at 15:40 +0530, Vasant Hegde wrote:
> This patch adds paltform devices for leds. Also export LED related
> OPAL API's so that led driver can use these APIs.
> 
> Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>

Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>


> ---
>  arch/powerpc/platforms/powernv/opal.c |   12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
> index 2241565..b1951aa 100644
> --- a/arch/powerpc/platforms/powernv/opal.c
> +++ b/arch/powerpc/platforms/powernv/opal.c
> @@ -784,7 +784,7 @@ static void opal_init_heartbeat(void)
>  
>  static int __init opal_init(void)
>  {
> -	struct device_node *np, *consoles;
> +	struct device_node *np, *consoles, *led;
>  	int rc;
>  
>  	opal_node = of_find_node_by_path("/ibm,opal");
> @@ -813,6 +813,13 @@ static int __init opal_init(void)
>  	/* Setup a heatbeat thread if requested by OPAL */
>  	opal_init_heartbeat();
>  
> +	/* Create led platform devices */
> +	led = of_find_node_by_path("/ibm,opal/led");
> +	if (led) {
> +		of_platform_device_create(led, "opal_led", NULL);
> +		of_node_put(led);
> +	}
> +
>  	/* Find all OPAL interrupts and request them */
>  	opal_irq_init(opal_node);
>  
> @@ -970,3 +977,6 @@ EXPORT_SYMBOL_GPL(opal_rtc_write);
>  EXPORT_SYMBOL_GPL(opal_tpo_read);
>  EXPORT_SYMBOL_GPL(opal_tpo_write);
>  EXPORT_SYMBOL_GPL(opal_i2c_request);
> +/* Export these symbols for PowerNV LED class driver */
> +EXPORT_SYMBOL_GPL(opal_leds_get_ind);
> +EXPORT_SYMBOL_GPL(opal_leds_set_ind);

Re: [PATCH v4 3/3] leds/powernv: Add driver for PowerNV platform

[Benjamin Herrenschmidt]

On Tue, 2015-04-28 at 15:40 +0530, Vasant Hegde wrote:

> +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>;
> +	};
> +	...
> +	...
> +};

My only issue is that /led should probably have been /leds but afaik
this is already committed in the FW tree. Vasant, have we done a release
what that code yet or can we still change this ?

Also what does led-mode = "lightpath" means ? Can you describe it ?
Are there alternative values ? I don't see the point myself ...

Don't leave the "linux,phandle" in the description of the binding (nor
the phandle actually). They are implicit for all nodes, no need to
clutter the documentation with them.

> +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.

I don't understand what that means. Please provide a more detailed
explanation.

Is the name of the node the loc code of the FRU ? In that case, how do
you deal with multiple LEDs on the same FRU without a unit address ?

Cheers,
Ben.

> 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 <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>
> +
> +/*
> + * 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 <hegdevasant@linux.vnet.ibm.com>");

Re: [PATCH v4 3/3] leds/powernv: Add driver for PowerNV platform

[Vasant Hegde]

On 06/25/2015 06:39 AM, Benjamin Herrenschmidt wrote:
> On Tue, 2015-04-28 at 15:40 +0530, Vasant Hegde wrote:
> 
>> +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>;
>> +	};
>> +	...
>> +	...
>> +};

Ben,

> 
> My only issue is that /led should probably have been /leds but afaik
> this is already committed in the FW tree. Vasant, have we done a release
> what that code yet or can we still change this ?

I think we can change OPAL side as we haven't released kernel code... So no
consumer yet.
Will send a patch to skiboot mailing list. lets see

> 
> Also what does led-mode = "lightpath" means ? Can you describe it ?
> Are there alternative values ? I don't see the point myself ...

Yes.. Our system can work in two modes...
   - light path --> Both identify and faults are supported
     typically all low end servers are in this mode
  - guiding light -> Only identify LEDs are supports . no fault indicator
support for individual FRU
     typically high end servers are in this mode.

These modes are static in nature.. meaning we cannot change that during run time...
AFAIK all the PowerNV boxes shipped today are in Light Path mode.. I have added
this, so that in future if they decide to ship system with guiding light mode,
then we don't need to make any changes.


> 
> Don't leave the "linux,phandle" in the description of the binding (nor
> the phandle actually). They are implicit for all nodes, no need to
> clutter the documentation with them.

Sure. Will fix in next version.


> 
>> +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.
> 
> I don't understand what that means. Please provide a more detailed
> explanation.
> 

This describes the LED location (FRU or enclosure level).. This was added to
identify the component (as FRU leds are overloaded and enclosure level we have
separate LEDs for each component)...


> Is the name of the node the loc code of the FRU ? In that case, how do
> you deal with multiple LEDs on the same FRU without a unit address ?

We use location code + LED type for node. So that we can identify multiple LEDs.

Looking back again, probably we can take out above property as we are not using
that today.

-Vasant