kernel.git/drivers/w1/slaves, branch linux-5.9.y

w1_therm: remove redundant assignments to variable ret

2020-05-21T08:58:51Z

The variable ret is being initialized with a value that is never read and it is being updated later with a new value. The initialization is redundant and can be removed. Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King Link: https://lore.kernel.org/r/20200519154553.873413-1-colin.king@canonical.com Signed-off-by: Greg Kroah-Hartman

w1_therm: Free the correct variable

2020-05-21T08:58:46Z

The problem is that we change "p_args" to point to the middle of the string so when we free it at the end of the function it's not freeing the same pointer that we originally allocated. Fixes: e2c94d6f5720 ("w1_therm: adding alarm sysfs entry") Signed-off-by: Dan Carpenter Link: https://lore.kernel.org/r/20200520120019.GA172354@mwanda Signed-off-by: Greg Kroah-Hartman

w1_therm: adding bulk read support to trigger multiple conversion on bus

2020-05-15T14:29:00Z

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 Link: https://lore.kernel.org/r/20200511203820.411483-1-akira215corp@gmail.com Signed-off-by: Greg Kroah-Hartman

w1_therm: adding alarm sysfs entry

2020-05-15T14:29:00Z

Adding device alarms settings by a dedicated sysfs entry alarms (RW): read or write TH and TL in the device RAM. Checking devices in alarm state could be performed using the master search command. As alarms temperature level are store in a 8 bit register on the device and are signed values, a safe cast shall be performed using the min and max temperature that device are able to measure. This is done by int_to_short inline function. A 'write_data' field is added in the device structure, to bind the correct writing function, as some devices may have 2 or 3 bytes RAM. Updating Documentation/ABI/testing/sysfs-driver-w1_therm accordingly. Signed-off-by: Akira Shimahara Link: https://lore.kernel.org/r/20200511203801.411253-1-akira215corp@gmail.com Signed-off-by: Greg Kroah-Hartman

w1_therm: optimizing temperature read timings

2020-05-15T14:28:59Z

Optimizing temperature reading by reducing waiting conversion time according to device resolution settings, as per device specification. This is device dependent as not all the devices supports resolution setting, so it has been added in device family structures. The process to read the temperature on the device has been adapted in a new function 'convert_t()', which replace the former 'read_therm()', is introduce to deal with this timing. Strong pull up is also applied during the required time, according to device power status needs and 'strong_pullup' module parameter. 'temperature_from_RAM()' function is introduced to get the correct temperature computation (device dependent) from device RAM data. An new sysfs entry has been added to ouptut only temperature. The old entry w1_slave has been kept for compatibility, without changing its output format. Updating Documentation/ABI/testing/sysfs-driver-w1_therm accordingly. Signed-off-by: Akira Shimahara Link: https://lore.kernel.org/r/20200511203742.411039-1-akira215corp@gmail.com Signed-off-by: Greg Kroah-Hartman

w1_therm: adding eeprom sysfs entry

2020-05-15T14:28:59Z

The driver implement 2 hardware functions to access device RAM: * copy_scratchpad * recall_scratchpad They act according to device specifications. As EEPROM operations are not device dependent (all w1_therm can perform EEPROM read/write operation following the same protocol), it is removed from device families structures. Updating Documentation/ABI/testing/sysfs-driver-w1_therm accordingly. Signed-off-by: Akira Shimahara Link: https://lore.kernel.org/r/20200511203725.410844-1-akira215corp@gmail.com Signed-off-by: Greg Kroah-Hartman

w1_therm: adding resolution sysfs entry

2020-05-15T14:28:59Z

Adding resolution sysfs entry (RW) to get or set the device resolution Write values are managed as follow: * '9..12': resolution to set in bit * Anything else: do nothing Read values are : * '9..12': device resolution in bit * '-xx': xx is kernel error when reading the resolution Only supported devices will show the sysfs entry. A new family has been created for DS18S20 devices as they do not implement resolution feature. The resolution of each device is check when the device is discover by the bus master, in 'w1_therm_add_slave(struct w1_slave *)'. The status is stored in the device structure w1_therm_family_data so that the driver always knows the resolution of each device, which could be used later to determine the required conversion duration (resolution dependent). The resolution is re evaluate each time a user read or write the sysfs entry. To avoid looping through the w1_therm_families at run time, the pointer 'specific_functions' is set up to the correct 'w1_therm_family_converter' when the slave is added (which mean when it is discovered by the master). This initialization is done by a helper function 'device_family(struct w1_slave *sl)', and a dedicated macro 'SLAVE_SPECIFIC_FUNC(sl)' allow the access to the specific function of the slave device. 'read_scratchpad' and 'write_scratchpad' are the hardware functions to access the device RAM, as per protocol specification. It cancel the former 'precision' functions, which was only set and never read (so not stored in the device struct). Updating Documentation/ABI/testing/sysfs-driver-w1_therm accordingly. Signed-off-by: Akira Shimahara Link: https://lore.kernel.org/r/20200511203708.410649-1-akira215corp@gmail.com Signed-off-by: Greg Kroah-Hartman

w1_therm: adding ext_power sysfs entry

2020-05-15T14:28:59Z

Adding ext_power sysfs entry (RO). Return the power status of the device: - 0: device parasite powered - 1: device externally powered - xx: xx is kernel error The power status of each device is check when the device is discover by the bus master, in 'w1_therm_add_slave(struct w1_slave *)'. The status is stored in the device structure w1_therm_family_data so that the driver always knows the power state of each device, which could be used later to determine the required strong pull up to apply on the line. The power status is re evaluate each time the sysfs ext_power read by a user. The hardware function 'read_powermode(struct w1_slave *sl)' act just as per device specifications, sending W1_READ_PSUPPLY command on the bus, and issue a read time slot, reading only one bit. A helper function 'bool bus_mutex_lock(struct mutex *lock)' is introduced. It try to aquire the bus mutex several times (W1_THERM_MAX_TRY), waiting W1_THERM_RETRY_DELAY between two attempt. Updating Documentation/ABI/testing/sysfs-driver-w1_therm accordingly. Signed-off-by: Akira Shimahara Link: https://lore.kernel.org/r/20200511203650.410439-1-akira215corp@gmail.com Signed-off-by: Greg Kroah-Hartman

w1_therm: fix reset_select_slave during discovery

2020-05-15T14:28:58Z

Fix reset_select_slave issue during devices discovery by the master on bus. The w1_reset_select_slave() from w1_io.c, which was previously used, assume that if the slave count is 1 there is only one slave attached on the bus. This is not always true. For example when discovering devices, when the first device is discover by the bus master, its slave count is 1, but some other slaves may be on the bus. In that case instead of adressing command to the attached slave the master throw a SKIP ROM command so that all slaves attached on the bus will answer simultenaously causing data collision. A dedicated reset_select_slave() function is implemented here, it always perform an adressing to each slave using the MATCH ROM command. Signed-off-by: Akira Shimahara Link: https://lore.kernel.org/r/20200511203610.409975-1-akira215corp@gmail.com Signed-off-by: Greg Kroah-Hartman

w1_therm: adding code comments and code reordering

2020-05-15T14:28:58Z

Adding code comments to split code in dedicated parts. After the global declarations (defines, macros and function declarations), code is organized as follow : - Device and family dependent structures and functions - Interfaces functions - Helpers functions - Hardware functions - Sysfs interface functions Signed-off-by: Akira Shimahara Link: https://lore.kernel.org/r/20200511203535.409599-1-akira215corp@gmail.com Signed-off-by: Greg Kroah-Hartman