kernel/linux.git/include/linux/spi/spi.h, branch linux-5.8.y

docs: spi: spi.h: fix a doc building warning

2020-04-20T21:45:23+00:00

We need to add a blank line to avoid this warning: ./include/linux/spi/spi.h:401: WARNING: Unexpected indentation. Signed-off-by: Mauro Carvalho Chehab Link: https://lore.kernel.org/r/1c701b3ac903dc0bc304dca958fbdee53bd38dc3.1586881715.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet

spi: update the structure documentation

2020-03-10T14:30:57+00:00

some members were not described in documentation. Signed-off-by: Qiujun Huang Link: https://lore.kernel.org/r/1583774179-30736-1-git-send-email-hqjagain@gmail.com Signed-off-by: Mark Brown

spi: Do spi_take_timestamp_pre for as many times as necessary

2020-03-05T14:06:19+00:00

When dealing with a SPI controller driver that is sending more than 1 byte at once (or the entire buffer at once), and the SPI peripheral driver has requested timestamping for a byte in the middle of the buffer, we find that spi_take_timestamp_pre never records a "pre" timestamp. This happens because the function currently expects to be called with the "progress" argument >= to what the peripheral has requested to be timestamped. But clearly there are cases when that isn't going to fly. And since we can't change the past when we realize that the opportunity to take a "pre" timestamp has just passed and there isn't going to be another one, the approach taken is to keep recording the "pre" timestamp on each call, overwriting the previously recorded one until the "post" timestamp is also taken. Signed-off-by: Vladimir Oltean Link: https://lore.kernel.org/r/20200304220044.11193-8-olteanv@gmail.com Signed-off-by: Mark Brown

spi: Allow SPI controller override device buswidth

2020-02-28T18:01:42+00:00

Currently ACPI firmware description for a SPI device does not have any method to describe the data buswidth on the board. So even through the controller and device may support higher modes than standard SPI, it cannot be assumed that the board does - as such, that device is limited to standard SPI in such a circumstance. As a workaround, allow the controller driver supply buswidth override bits, which are used inform the core code that the controller driver knows the buswidth supported on that board for that device. A host controller driver might know this info from DMI tables, for example. Signed-off-by: John Garry Link: https://lore.kernel.org/r/1582903131-160033-2-git-send-email-john.garry@huawei.com Signed-off-by: Mark Brown

Merge branch 'spi-5.6' into spi-next

2020-01-23T12:37:18+00:00

spi: Add generic support for unused native cs with cs-gpios

2020-01-07T22:32:25+00:00

Some SPI master controllers always drive a native chip select when performing a transfer. Hence when using both native and GPIO chip selects, at least one native chip select must be left unused, to be driven when performing transfers with slave devices using GPIO chip selects. Currently, to find an unused native chip select, SPI controller drivers need to parse and process cs-gpios theirselves. This is not only duplicated in each driver that needs it, but also duplicates part of the work done later at SPI controller registration time. Note that this cannot be done after spi_register_controller() returns, as at that time, slave devices may have been probed already. Hence add generic support to the SPI subsystem for finding an unused native chip select. Optionally, this unused native chip select, and all other in-use native chip selects, can be validated against the maximum number of native chip selects available on the controller hardware. Signed-off-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/20200102133822.29346-2-geert+renesas@glider.be Signed-off-by: Mark Brown

spi: Don't look at TX buffer for PTP system timestamping

2019-12-27T23:03:43+00:00

The API for PTP system timestamping (associating a SPI transaction with the system time at which it was transferred) is flawed: it assumes that the xfer->tx_buf pointer will always be present. This is, of course, not always the case. So introduce a "progress" variable that denotes how many word have been transferred. Fix the Freescale DSPI driver, the only user of the API so far, in the same patch. Fixes: b42faeee718c ("spi: Add a PTP system timestamp to the transfer structure") Fixes: d6b71dfaeeba ("spi: spi-fsl-dspi: Implement the PTP system timestamping for TCFQ mode") Signed-off-by: Vladimir Oltean Link: https://lore.kernel.org/r/20191227012417.1057-1-olteanv@gmail.com Signed-off-by: Mark Brown

spi: document CS setup, hold & inactive times in header

2019-10-23T16:48:57+00:00

This change documents the CS setup, host & inactive times. They were omitted when the fields were added, and were caught by one of the build bots. Fixes: 25093bdeb6bc ("spi: implement SW control for CS times") Reported-by: kbuild test robot Signed-off-by: Alexandru Ardelean Link: https://lore.kernel.org/r/20191023070046.12478-1-alexandru.ardelean@analog.com Signed-off-by: Mark Brown

spi: spi-fsl-espi: convert transfer delay to `spi_delay` format

2019-10-15T10:46:34+00:00

The way the max delay is computed for this controller, it looks like it is searching for the max delay from an SPI message a using that. No idea if this is valid. But this change should support both `delay_usecs` and the new `delay` data which is of `spi_delay` type. Signed-off-by: Alexandru Ardelean Link: https://lore.kernel.org/r/20190926105147.7839-17-alexandru.ardelean@analog.com Signed-off-by: Mark Brown

spi: implement SW control for CS times

2019-10-15T10:46:12+00:00

This change implements CS control for setup, hold & inactive delays. The `cs_setup` delay is completely new, and can help with cases where asserting the CS, also brings the device out of power-sleep, where there needs to be a longer (than usual), before transferring data. The `cs_hold` time can overlap with the `delay` (or `delay_usecs`) from an SPI transfer. The main difference is that `cs_hold` implies that CS will be de-asserted. The `cs_inactive` delay does not have a clear use-case yet. It has been implemented mostly because the `spi_set_cs_timing()` function implements it. To some degree, this could overlap or replace `cs_change_delay`, but this will require more consideration/investigation in the future. All these delays have been added to the `spi_controller` struct, as they would typically be configured by calling `spi_set_cs_timing()` after an `spi_setup()` call. Software-mode for CS control, implies that the `set_cs_timing()` hook has not been provided for the `spi_controller` object. Signed-off-by: Alexandru Ardelean Link: https://lore.kernel.org/r/20190926105147.7839-16-alexandru.ardelean@analog.com Signed-off-by: Mark Brown