bcm27xx: import latest patches from the RPi foundation

bcm2708: boot tested on RPi B+ v1.2
bcm2709: boot tested on RPi 3B v1.2 and RPi 4B v1.1 4G
bcm2710: boot tested on RPi 3B v1.2
bcm2711: boot tested on RPi 4B v1.1 4G

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>

1 files changed, 587 insertions, 0 deletions

diff --git a/target/linux/bcm27xx/patches-5.4/950-0773-w1_therm-adding-bulk-read-support-to-trigger-multipl.patch b/target/linux/bcm27xx/patches-5.4/950-0773-w1_therm-adding-bulk-read-support-to-trigger-multipl.patch
new file mode 100644
index 0000000000..ad641e1e98
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.4/950-0773-w1_therm-adding-bulk-read-support-to-trigger-multipl.patch
@@ -0,0 +1,587 @@
+From e6585a1d299375740f95f30027b8b3f4b34e7548 Mon Sep 17 00:00:00 2001
+From: Akira Shimahara <akira215corp@gmail.com>
+Date: Mon, 11 May 2020 22:38:20 +0200
+Subject: [PATCH] w1_therm: adding bulk read support to trigger
+ multiple conversion on bus
+
+commit 57c76221d5af648c8355a55c09b050c5d8d38189 upstream.
+
+Adding bulk read support:
+Sending a 'trigger' command in the dedicated sysfs entry of bus master
+device send a conversion command for all the slaves on the bus. The sysfs
+entry is added as soon as at least one device supporting this feature
+is detected on the bus.
+
+The behavior of the sysfs reading temperature on the device is as follow:
+ * If no bulk read pending, trigger a conversion on the device, wait for
+ the conversion to be done, read the temperature in device RAM
+ * If a bulk read has been trigger, access directly the device RAM
+This behavior is the same on the 2 sysfs entries ('temperature' and
+'w1_slave').
+
+Reading the therm_bulk_read sysfs give the status of bulk operations:
+ * '-1': conversion in progress on at least 1 sensor
+ * '1': conversion complete but at least one sensor has not been read yet
+ * '0': no bulk operation. Reading temperature on ecah device will trigger
+a conversion
+
+As not all devices support bulk read feature, it has been added in device
+family structure.
+
+The attribute is set at master level as soon as a supporting device is
+discover. It is removed when the last supported device leave the bus.
+The count of supported device is kept with the static counter
+bulk_read_device_counter.
+
+A strong pull up is apply on the line if at least one device required it.
+The duration of the pull up is the max time required by a device on the
+line, which depends on the resolution settings of each device. The strong
+pull up could be adjust with the a module parameter.
+
+Updating documentation in Documentation/ABI/testing/sysfs-driver-w1_therm
+and Documentation/w1/slaves/w1_therm.rst accordingly.
+
+Signed-off-by: Akira Shimahara <akira215corp@gmail.com>
+Link: https://lore.kernel.org/r/20200511203820.411483-1-akira215corp@gmail.com
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ .../ABI/testing/sysfs-driver-w1_therm         |  36 ++-
+ Documentation/w1/slaves/w1_therm.rst          |  50 +++-
+ drivers/w1/slaves/w1_therm.c                  | 251 +++++++++++++++++-
+ 3 files changed, 322 insertions(+), 15 deletions(-)
+
+--- a/Documentation/ABI/testing/sysfs-driver-w1_therm
++++ b/Documentation/ABI/testing/sysfs-driver-w1_therm
+@@ -62,9 +62,16 @@ Date:		May 2020
+ Contact:	Akira Shimahara <akira215corp@gmail.com>
+ Description:
+ 		(RO) return the temperature in 1/1000 degC.
+-		Note that the conversion duration depend on the resolution (if
+-		device support this feature). It takes 94ms in 9bits
+-		resolution, 750ms for 12bits.
++			* If a bulk read has been triggered, it will directly
++			return the temperature computed when the bulk read
++			occurred, if available. If not yet available, nothing
++			is returned (a debug kernel message is sent), you
++			should retry later on.
++			* If no bulk read has been triggered, it will trigger
++			a conversion and send the result. Note that the
++			conversion duration depend on the resolution (if
++			device support this feature). It takes 94ms in 9bits
++			resolution, 750ms for 12bits.
+ Users:		any user space application which wants to communicate with
+ 		w1_term device
+ 
+@@ -85,4 +92,25 @@ Description:
+ 		refer to Documentation/w1/slaves/w1_therm.rst for detailed
+ 		information.
+ Users:		any user space application which wants to communicate with
+-		w1_term device
+\ No newline at end of file
++		w1_term device
++
++
++What:		/sys/bus/w1/devices/w1_bus_masterXX/therm_bulk_read
++Date:		May 2020
++Contact:	Akira Shimahara <akira215corp@gmail.com>
++Description:
++		(RW) trigger a bulk read conversion. read the status
++		*read*:
++			* '-1': conversion in progress on at least 1 sensor
++			* '1' :	conversion complete but at least one sensor
++				value has not been read yet
++			* '0' :	no bulk operation. Reading temperature will
++				trigger a conversion on each device
++		*write*: 'trigger': trigger a bulk read on all supporting
++			devices on the bus
++		Note that if a bulk read is sent but one sensor is not read
++		immediately, the next access to temperature on this device
++		will return the temperature measured at the time of issue
++		of the bulk read command (not the current temperature).
++Users:		any user space application which wants to communicate with
++		w1_term device
+--- a/Documentation/w1/slaves/w1_therm.rst
++++ b/Documentation/w1/slaves/w1_therm.rst
+@@ -26,20 +26,31 @@ W1_THERM_DS1825		0x3B
+ W1_THERM_DS28EA00	0x42
+ ====================	====
+ 
+-Support is provided through the sysfs w1_slave file.  Each open and
++Support is provided through the sysfs w1_slave file. Each open and
+ read sequence will initiate a temperature conversion then provide two
+-lines of ASCII output.  The first line contains the nine hex bytes
++lines of ASCII output. The first line contains the nine hex bytes
+ read along with a calculated crc value and YES or NO if it matched.
+-If the crc matched the returned values are retained.  The second line
++If the crc matched the returned values are retained. The second line
+ displays the retained values along with a temperature in millidegrees
+ Centigrade after t=.
+ 
+-Parasite powered devices are limited to one slave performing a
+-temperature conversion at a time.  If none of the devices are parasite
+-powered it would be possible to convert all the devices at the same
+-time and then go back to read individual sensors.  That isn't
+-currently supported.  The driver also doesn't support reduced
+-precision (which would also reduce the conversion time) when reading values.
++Alternatively, temperature can be read using temperature sysfs, it
++return only temperature in millidegrees Centigrade.
++
++A bulk read of all devices on the bus could be done writing 'trigger'
++in the therm_bulk_read sysfs entry at w1_bus_master level. This will
++sent the convert command on all devices on the bus, and if parasite
++powered devices are detected on the bus (and strong pullup is enable
++in the module), it will drive the line high during the longer conversion
++time required by parasited powered device on the line. Reading
++therm_bulk_read will return 0 if no bulk conversion pending,
++-1 if at least one sensor still in conversion, 1 if conversion is complete
++but at least one sensor value has not been read yet. Result temperature is
++then accessed by reading the temperature sysfs entry of each device, which
++may return empty if conversion is still in progress. Note that if a bulk
++read is sent but one sensor is not read immediately, the next access to
++temperature on this device will return the temperature measured at the
++time of issue of the bulk read command (not the current temperature).
+ 
+ Writing a value between 9 and 12 to the sysfs w1_slave file will change the
+ precision of the sensor for the next readings. This value is in (volatile)
+@@ -49,6 +60,27 @@ To store the current precision configura
+ has to be written to the sysfs w1_slave file. Since the EEPROM has a limited
+ amount of writes (>50k), this command should be used wisely.
+ 
++Alternatively, resolution can be set or read (value from 9 to 12) using the
++dedicated resolution sysfs entry on each device. This sysfs entry is not
++present for devices not supporting this feature. Driver will adjust the
++correct conversion time for each device regarding to its resolution setting.
++In particular, strong pullup will be applied if required during the conversion
++duration.
++
++The write-only sysfs entry eeprom is an alternative for EEPROM operations:
++  * 'save': will save device RAM to EEPROM
++  * 'restore': will restore EEPROM data in device RAM.
++
++ext_power syfs entry allow tho check the power status of each device.
++  * '0': device parasite powered
++  * '1': device externally powered
++
++sysfs alarms allow read or write TH and TL (Temperature High an Low) alarms.
++Values shall be space separated and in the device range (typical -55 degC
++to 125 degC). Values are integer as they are store in a 8bit register in
++the device. Lowest value is automatically put to TL.Once set, alarms could
++be search at master level.
++
+ The module parameter strong_pullup can be set to 0 to disable the
+ strong pullup, 1 to enable autodetection or 2 to force strong pullup.
+ In case of autodetection, the driver will use the "READ POWER SUPPLY"
+--- a/drivers/w1/slaves/w1_therm.c
++++ b/drivers/w1/slaves/w1_therm.c
+@@ -43,6 +43,9 @@
+ static int w1_strong_pullup = 1;
+ module_param_named(strong_pullup, w1_strong_pullup, int, 0);
+ 
++/* Counter for devices supporting bulk reading */
++static u16 bulk_read_device_counter; /* =0 as per C standard */
++
+ /* This command should be in public header w1.h but is not */
+ #define W1_RECALL_EEPROM	0xB8
+ 
+@@ -57,6 +60,7 @@ module_param_named(strong_pullup, w1_str
+ 
+ #define EEPROM_CMD_WRITE    "save"	/* cmd for write eeprom sysfs */
+ #define EEPROM_CMD_READ     "restore"	/* cmd for read eeprom sysfs */
++#define BULK_TRIGGER_CMD    "trigger"	/* cmd to trigger a bulk read */
+ 
+ #define MIN_TEMP	-55	/* min temperature that can be mesured */
+ #define MAX_TEMP	125	/* max temperature that can be mesured */
+@@ -84,6 +88,15 @@ module_param_named(strong_pullup, w1_str
+ #define SLAVE_RESOLUTION(sl) \
+ 	(((struct w1_therm_family_data *)(sl->family_data))->resolution)
+ 
++/*
++ * return whether or not a converT command has been issued to the slave
++ * * 0: no bulk read is pending
++ * * -1: conversion is in progress
++ * * 1: conversion done, result to be read
++ */
++#define SLAVE_CONVERT_TRIGGERED(sl) \
++	(((struct w1_therm_family_data *)(sl->family_data))->convert_triggered)
++
+ /* return the address of the refcnt in the family data */
+ #define THERM_REFCNT(family_data) \
+ 	(&((struct w1_therm_family_data *)family_data)->refcnt)
+@@ -100,6 +113,7 @@ module_param_named(strong_pullup, w1_str
+  * @set_resolution: pointer to the device set_resolution function
+  * @get_resolution: pointer to the device get_resolution function
+  * @write_data: pointer to the device writing function (2 or 3 bytes)
++ * @bulk_read: true if device family support bulk read, false otherwise
+  */
+ struct w1_therm_family_converter {
+ 	u8		broken;
+@@ -110,6 +124,7 @@ struct w1_therm_family_converter {
+ 	int		(*set_resolution)(struct w1_slave *sl, int val);
+ 	int		(*get_resolution)(struct w1_slave *sl);
+ 	int		(*write_data)(struct w1_slave *sl, const u8 *data);
++	bool		bulk_read;
+ };
+ 
+ /**
+@@ -120,6 +135,7 @@ struct w1_therm_family_converter {
+  *				0 device parasite powered,
+  *				-x error or undefined
+  * @resolution: current device resolution
++ * @convert_triggered: conversion state of the device
+  * @specific_functions: pointer to struct of device specific function
+  */
+ struct w1_therm_family_data {
+@@ -127,6 +143,7 @@ struct w1_therm_family_data {
+ 	atomic_t refcnt;
+ 	int external_powered;
+ 	int resolution;
++	int convert_triggered;
+ 	struct w1_therm_family_converter *specific_functions;
+ };
+ 
+@@ -218,6 +235,18 @@ static int recall_eeprom(struct w1_slave
+  */
+ static int read_powermode(struct w1_slave *sl);
+ 
++/**
++ * trigger_bulk_read() - function to trigger a bulk read on the bus
++ * @dev_master: the device master of the bus
++ *
++ * Send a SKIP ROM follow by a CONVERT T commmand on the bus.
++ * It also set the status flag in each slave &struct w1_therm_family_data
++ * to signal that a conversion is in progress.
++ *
++ * Return: 0 if success, -kernel error code otherwise
++ */
++static int trigger_bulk_read(struct w1_master *dev_master);
++
+ /* Sysfs interface declaration */
+ 
+ static ssize_t w1_slave_show(struct device *device,
+@@ -250,6 +279,12 @@ static ssize_t alarms_store(struct devic
+ static ssize_t alarms_show(struct device *device,
+ 	struct device_attribute *attr, char *buf);
+ 
++static ssize_t therm_bulk_read_store(struct device *device,
++	struct device_attribute *attr, const char *buf, size_t size);
++
++static ssize_t therm_bulk_read_show(struct device *device,
++	struct device_attribute *attr, char *buf);
++
+ /* Attributes declarations */
+ 
+ static DEVICE_ATTR_RW(w1_slave);
+@@ -260,6 +295,8 @@ static DEVICE_ATTR_RW(resolution);
+ static DEVICE_ATTR_WO(eeprom);
+ static DEVICE_ATTR_RW(alarms);
+ 
++static DEVICE_ATTR_RW(therm_bulk_read); /* attribut at master level */
++
+ /* Interface Functions declaration */
+ 
+ /**
+@@ -572,6 +609,7 @@ static struct w1_therm_family_converter
+ 		.set_resolution		= NULL,	/* no config register */
+ 		.get_resolution		= NULL,	/* no config register */
+ 		.write_data			= w1_DS18S20_write_data,
++		.bulk_read			= true
+ 	},
+ 	{
+ 		.f				= &w1_therm_family_DS1822,
+@@ -580,6 +618,7 @@ static struct w1_therm_family_converter
+ 		.set_resolution		= w1_DS18B20_set_resolution,
+ 		.get_resolution		= w1_DS18B20_get_resolution,
+ 		.write_data			= w1_DS18B20_write_data,
++		.bulk_read			= true
+ 	},
+ 	{
+ 		.f				= &w1_therm_family_DS18B20,
+@@ -588,6 +627,7 @@ static struct w1_therm_family_converter
+ 		.set_resolution		= w1_DS18B20_set_resolution,
+ 		.get_resolution		= w1_DS18B20_get_resolution,
+ 		.write_data			= w1_DS18B20_write_data,
++		.bulk_read			= true
+ 	},
+ 	{
+ 		.f				= &w1_therm_family_DS28EA00,
+@@ -596,6 +636,7 @@ static struct w1_therm_family_converter
+ 		.set_resolution		= w1_DS18B20_set_resolution,
+ 		.get_resolution		= w1_DS18B20_get_resolution,
+ 		.write_data			= w1_DS18B20_write_data,
++		.bulk_read			= false
+ 	},
+ 	{
+ 		.f				= &w1_therm_family_DS1825,
+@@ -604,6 +645,7 @@ static struct w1_therm_family_converter
+ 		.set_resolution		= w1_DS18B20_set_resolution,
+ 		.get_resolution		= w1_DS18B20_get_resolution,
+ 		.write_data			= w1_DS18B20_write_data,
++		.bulk_read			= true
+ 	}
+ };
+ 
+@@ -658,6 +700,23 @@ static inline bool bus_mutex_lock(struct
+ }
+ 
+ /**
++ * support_bulk_read() - check if slave support bulk read
++ * @sl: device to check the ability
++ *
++ * Return: true if bulk read is supported, false if not or error
++ */
++static inline bool bulk_read_support(struct w1_slave *sl)
++{
++	if (SLAVE_SPECIFIC_FUNC(sl))
++		return SLAVE_SPECIFIC_FUNC(sl)->bulk_read;
++
++	dev_info(&sl->dev,
++		"%s: Device not supported by the driver\n", __func__);
++
++	return false;  /* No device family */
++}
++
++/**
+  * conversion_time() - get the Tconv for the slave
+  * @sl: device to get the conversion time
+  *
+@@ -741,6 +800,24 @@ static int w1_therm_add_slave(struct w1_
+ 	/* save this pointer to the device structure */
+ 	SLAVE_SPECIFIC_FUNC(sl) = sl_family_conv;
+ 
++	if (bulk_read_support(sl)) {
++		/*
++		 * add the sys entry to trigger bulk_read
++		 * at master level only the 1st time
++		 */
++		if (!bulk_read_device_counter) {
++			int err = device_create_file(&sl->master->dev,
++				&dev_attr_therm_bulk_read);
++
++			if (err)
++				dev_warn(&sl->dev,
++				"%s: Device has been added, but bulk read is unavailable. err=%d\n",
++				__func__, err);
++		}
++		/* Increment the counter */
++		bulk_read_device_counter++;
++	}
++
+ 	/* Getting the power mode of the device {external, parasite} */
+ 	SLAVE_POWERMODE(sl) = read_powermode(sl);
+ 
+@@ -763,6 +840,9 @@ static int w1_therm_add_slave(struct w1_
+ 		}
+ 	}
+ 
++	/* Finally initialize convert_triggered flag */
++	SLAVE_CONVERT_TRIGGERED(sl) = 0;
++
+ 	return 0;
+ }
+ 
+@@ -770,6 +850,14 @@ static void w1_therm_remove_slave(struct
+ {
+ 	int refcnt = atomic_sub_return(1, THERM_REFCNT(sl->family_data));
+ 
++	if (bulk_read_support(sl)) {
++		bulk_read_device_counter--;
++		/* Delete the entry if no more device support the feature */
++		if (!bulk_read_device_counter)
++			device_remove_file(&sl->master->dev,
++				&dev_attr_therm_bulk_read);
++	}
++
+ 	while (refcnt) {
+ 		msleep(1000);
+ 		refcnt = atomic_read(THERM_REFCNT(sl->family_data));
+@@ -1084,6 +1172,96 @@ error:
+ 	return ret;
+ }
+ 
++static int trigger_bulk_read(struct w1_master *dev_master)
++{
++	struct w1_slave *sl = NULL; /* used to iterate through slaves */
++	int max_trying = W1_THERM_MAX_TRY;
++	int t_conv = 0;
++	int ret = -ENODEV;
++	bool strong_pullup = false;
++
++	/*
++	 * Check whether there are parasite powered device on the bus,
++	 * and compute duration of conversion for these devices
++	 * so we can apply a strong pullup if required
++	 */
++	list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) {
++		if (!sl->family_data)
++			goto error;
++		if (bulk_read_support(sl)) {
++			int t_cur = conversion_time(sl);
++
++			t_conv = t_cur > t_conv ? t_cur : t_conv;
++			strong_pullup = strong_pullup ||
++					(w1_strong_pullup == 2 ||
++					(!SLAVE_POWERMODE(sl) &&
++					w1_strong_pullup));
++		}
++	}
++
++	/*
++	 * t_conv is the max conversion time required on the bus
++	 * If its 0, no device support the bulk read feature
++	 */
++	if (!t_conv)
++		goto error;
++
++	if (!bus_mutex_lock(&dev_master->bus_mutex)) {
++		ret = -EAGAIN;	/* Didn't acquire the mutex */
++		goto error;
++	}
++
++	while ((max_trying--) && (ret < 0)) { /* ret should be either 0 */
++
++		if (!w1_reset_bus(dev_master)) {	/* Just reset the bus */
++			unsigned long sleep_rem;
++
++			w1_write_8(dev_master, W1_SKIP_ROM);
++
++			if (strong_pullup)	/* Apply pullup if required */
++				w1_next_pullup(dev_master, t_conv);
++
++			w1_write_8(dev_master, W1_CONVERT_TEMP);
++
++			/* set a flag to instruct that converT pending */
++			list_for_each_entry(sl,
++				&dev_master->slist, w1_slave_entry) {
++				if (bulk_read_support(sl))
++					SLAVE_CONVERT_TRIGGERED(sl) = -1;
++			}
++
++			if (strong_pullup) { /* some device need pullup */
++				sleep_rem = msleep_interruptible(t_conv);
++				if (sleep_rem != 0) {
++					ret = -EINTR;
++					goto mt_unlock;
++				}
++				mutex_unlock(&dev_master->bus_mutex);
++			} else {
++				mutex_unlock(&dev_master->bus_mutex);
++				sleep_rem = msleep_interruptible(t_conv);
++				if (sleep_rem != 0) {
++					ret = -EINTR;
++					goto set_flag;
++				}
++			}
++			ret = 0;
++			goto set_flag;
++		}
++	}
++
++mt_unlock:
++	mutex_unlock(&dev_master->bus_mutex);
++set_flag:
++	/* set a flag to register convsersion is done */
++	list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) {
++		if (bulk_read_support(sl))
++			SLAVE_CONVERT_TRIGGERED(sl) = 1;
++	}
++error:
++	return ret;
++}
++
+ /* Sysfs Interface definition */
+ 
+ static ssize_t w1_slave_show(struct device *device,
+@@ -1095,7 +1273,20 @@ static ssize_t w1_slave_show(struct devi
+ 	int ret, i;
+ 	ssize_t c = PAGE_SIZE;
+ 
+-	ret = convert_t(sl, &info);
++	if (bulk_read_support(sl)) {
++		if (SLAVE_CONVERT_TRIGGERED(sl) < 0) {
++			dev_dbg(device,
++				"%s: Conversion in progress, retry later\n",
++				__func__);
++			return 0;
++		} else if (SLAVE_CONVERT_TRIGGERED(sl) > 0) {
++			/* A bulk read has been issued, read the device RAM */
++			ret = read_scratchpad(sl, &info);
++			SLAVE_CONVERT_TRIGGERED(sl) = 0;
++		} else
++			ret = convert_t(sl, &info);
++	} else
++		ret = convert_t(sl, &info);
+ 
+ 	if (ret < 0) {
+ 		dev_dbg(device,
+@@ -1176,7 +1367,20 @@ static ssize_t temperature_show(struct d
+ 		return 0;  /* No device family */
+ 	}
+ 
+-	ret = convert_t(sl, &info);
++	if (bulk_read_support(sl)) {
++		if (SLAVE_CONVERT_TRIGGERED(sl) < 0) {
++			dev_dbg(device,
++				"%s: Conversion in progress, retry later\n",
++				__func__);
++			return 0;
++		} else if (SLAVE_CONVERT_TRIGGERED(sl) > 0) {
++			/* A bulk read has been issued, read the device RAM */
++			ret = read_scratchpad(sl, &info);
++			SLAVE_CONVERT_TRIGGERED(sl) = 0;
++		} else
++			ret = convert_t(sl, &info);
++	} else
++		ret = convert_t(sl, &info);
+ 
+ 	if (ret < 0) {
+ 		dev_dbg(device,
+@@ -1412,6 +1616,49 @@ free_m:
+ 	return size;
+ }
+ 
++static ssize_t therm_bulk_read_store(struct device *device,
++	struct device_attribute *attr, const char *buf, size_t size)
++{
++	struct w1_master *dev_master = dev_to_w1_master(device);
++	int ret = -EINVAL; /* Invalid argument */
++
++	if (size == sizeof(BULK_TRIGGER_CMD))
++		if (!strncmp(buf, BULK_TRIGGER_CMD,
++				sizeof(BULK_TRIGGER_CMD)-1))
++			ret = trigger_bulk_read(dev_master);
++
++	if (ret)
++		dev_info(device,
++			"%s: unable to trigger a bulk read on the bus. err=%d\n",
++			__func__, ret);
++
++	return size;
++}
++
++static ssize_t therm_bulk_read_show(struct device *device,
++	struct device_attribute *attr, char *buf)
++{
++	struct w1_master *dev_master = dev_to_w1_master(device);
++	struct w1_slave *sl = NULL;
++	int ret = 0;
++
++	list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) {
++		if (sl->family_data) {
++			if (bulk_read_support(sl)) {
++				if (SLAVE_CONVERT_TRIGGERED(sl) == -1) {
++					ret = -1;
++					goto show_result;
++				}
++				if (SLAVE_CONVERT_TRIGGERED(sl) == 1)
++					/* continue to check other slaves */
++					ret = 1;
++			}
++		}
++	}
++show_result:
++	return sprintf(buf, "%d\n", ret);
++}
++
+ #if IS_REACHABLE(CONFIG_HWMON)
+ static int w1_read_temp(struct device *device, u32 attr, int channel,
+ 			long *val)