i3c: mipi-i3c-hci: Add DMA bounce buffer for private transfers

Implement a local bounce buffer for private I3C SDR and I2C transfers
when using DMA and the buffer attached to the transfer is not DMA safe.

Otherwise the DMA transfer will fail and with following warning:

[ 11.411059] i3c mipi-i3c-hci.0: rejecting DMA map of vmalloc memory
[ 11.417313] WARNING: CPU: 3 PID: 357 at include/linux/dma-mapping.h:332 hci_dma_queue_xfer+0x2e2/0x300 [mipi_i3c_hci]

Strictly speaking private I3C SDR transfers are expected to pass a
DMA-able buffer. However I fear this requirement may easily be slipped
or go unnoticed when I3C interface support is added into a existing
device driver that use regmap API to read/write stack variables.

For example this is the case with the commit 2660b0080bb2 ("iio: imu:
st_lsm6dsx: add i3c basic support for LSM6DSO and LSM6DSR").

Buffer of an I2C message is not required to be DMA safe and the I2C core
provides i2c_(get|put)_dma_safe_msg_buf() helpers for the host
controllers that do DMA and that is also recommendation for the
i2c_xfers() callback from the I3C core.

However due to above I3C private transfers reason I decided to implement
a bounce buffer for them and reuse the same code for the I2C transfers
too. Since this driver is currently the only I3C host controller driver
that can do DMA the implementation is done here and not in I3C core.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Link: https://lore.kernel.org/r/20231109133708.653950-5-jarkko.nikula@linux.intel.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

i3c: mipi-i3c-hci: Report NACK response from CCC command to core

Currently probe of mipi-i3c-hci will fail if bus doesn't have any I3C
devices connected. This happens when CCC commands that are sent during
i3c_master_bus_init() are not ACKed by any device and controller responds
with an error status set.

The controller can detect NACK both during I3C address header
transmission (broadcast address 0x7e is not ACKed) and when target
device address or dynamic address assignment is NACKed. Former as error
status 0x4: Address Header Error and latter as 0x5: NACK.

Difference between those two NACK statuses were not described explicitly
until MIPI I3C HCI Specification v1.1. Earlier versions share the same
error status code though.

Report both of those as I3C_ERROR_M2 to I3C core code.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Link: https://lore.kernel.org/r/20231109133708.653950-2-jarkko.nikula@linux.intel.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

i3c: mipi-i3c-hci: Resume controller explicitly

On an HW I'm using in enabling work the RESUME bit is not set in the
HC_CONTROLLER register when Host Controller goes to halt state. Value 1
should mean controller is suspended when reading and writing 1 resumes it.

Because of this erratic behaviour plain HC_CONTROL read and write back
won't resume the controller. Therefore do it by setting the RESUME bit
explicitly.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Link: https://lore.kernel.org/r/20230921055704.1087277-12-jarkko.nikula@linux.intel.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

i3c: mipi-i3c-hci: Fix race between bus cleanup and interrupt

If there is a transfer error during i3c_master_bus_init() and code goes
doing the bus cleanup in i3c_hci_bus_cleanup() there is possibility that
i3c_hci_irq_handler() is running in parallel with hci->io->cleanup()
which can be racy.

Prevent this by waiting there is no pending interrupt on other CPU
before doing the IO cleanup.

This was observed with ring headers where first transfer failed and
sometimes transfer error or ring transfer abort interrupt was coming
simultaneously with the bus cleanup path.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Link: https://lore.kernel.org/r/20230921055704.1087277-8-jarkko.nikula@linux.intel.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

i3c: mipi-i3c-hci: Fix DAT/DCT entry sizes

MIPI I3C HCI specification v1.1 describes the ENTRY_SIZE field for the
Device Address Table (DAT) and the Device Characteristics Table (DCT)
section offset registers (DAT_SECTION_OFFSET and DCT_SECTION_OFFSET).
That field is not documented in earlier version.

ENTRY_SIZE value 0 is meant to be backward compatible. For the DAT entry
size it is interpreted as 2 DWORDs (8-bytes) and for the DCT entry size
as 4 DWORDs (16-bytes). Values 1-15 are reserved for future use.

New version I believe fixes also the TABLE_SIZE field description.
Before it was defined in DWORDs which I believe is incorrect since the
DAT/DCT table entry structures, and sizes, are described having
8-bytes/16-bytes entries.

This is more clear in the specification v1.1 which states the TABLE_SIZE
fields are interpreted as number of entries in the DAT/DCT tables. I
believe this same holds also in earlier version, at least it makes more
sense.

Fix code accordingly and let the DAT_entry_size and the DCT_entry_size
variables carry the size as bytes. Which is how it is already
interpreted in the dat_v1.c: hci_dat_v1_init().

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Link: https://lore.kernel.org/r/20230921055704.1087277-4-jarkko.nikula@linux.intel.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

i3c: mipi-i3c-hci: Add MODULE_ALIAS

Add MODULE_ALIAS() in order to be able to autoload this driver when the
device is added as a platform device from another glue code driver.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Link: https://lore.kernel.org/r/20230921055704.1087277-3-jarkko.nikula@linux.intel.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

i3c: mipi-i3c-hci: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230318233311.265186-5-u.kleine-koenig@pengutronix.de
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

i3c: Make i3c_master_unregister() return void

The function returned zero unconditionally. Switch the return type to void
and simplify the callers accordingly.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20230318233311.265186-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

i3c/master: simplify the return expression of i3c_hci_remove()

Simplify the return expression.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Minghao Chi <chi.minghao@zte.com.cn>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220505021954.54524-1-chi.minghao@zte.com.cn

i3c: master: mipi-i3c-hci: correct the config reference for endianness

The referred config BIG_ENDIAN does not exist. The config for the
endianness of the CPU architecture is called CPU_BIG_ENDIAN.

Correct the config name to the existing config for the endianness.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Acked-by: Nicolas Pitre <npitre@baylibre.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220103094504.3602-1-lukas.bulwahn@gmail.com

i3c/master/mipi-i3c-hci: Fix position of __maybe_unused in i3c_hci_of_match

Clang warns:

../drivers/i3c/master/mipi-i3c-hci/core.c:780:21: warning: attribute
declaration must precede definition [-Wignored-attributes]
static const struct __maybe_unused of_device_id i3c_hci_of_match[] = {
^
../include/linux/compiler_attributes.h:267:56: note: expanded from macro
'__maybe_unused'
#define __maybe_unused __attribute__((__unused__))
^
../include/linux/mod_devicetable.h:262:8: note: previous definition is
here
struct of_device_id {
^
1 warning generated.

'struct of_device_id' should not be split, as it is a type. Move the
__maybe_unused attribute after the static and const qualifiers so that
there are no warnings about this variable, period.

Fixes: 95393f3e07ab ("i3c/master/mipi-i3c-hci: quiet maybe-unused variable warning")
Link: https://github.com/ClangBuiltLinux/linux/issues/1221
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Acked-by: Nicolas Pitre <npitre@baylibre.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201222025931.3043480-1-natechancellor@gmail.com

i3c/master/mipi-i3c-hci: quiet maybe-unused variable warning

If CONFIG_OF is disabled then the matching table is notreferenced.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>

i3c/master: introduce the mipi-i3c-hci driver

This adds basic support for hardware implementing the MIPI I3C HCI
specification. This driver is currently limited by the capabilities
of the I3C subsystem, meaning things like scheduled commands,
auto-commands and NCM mode are not yet supported.

This supports version 1.0 of the MIPI I3C HCI spec, as well as the
imminent release of version 1.1. Support for draft version 2.0 of the
spec is also largely included with the caveat that future adjustments
to this code are likely as the spec is still a work in progress.

This is also lightly tested as actual hardware is still very scarce,
even for HCI v1.0. Hence the EXPERIMENTAL tag. Further contributions
to this driver are expected once vendor implementations and new I3C
devices become available.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://lore.kernel.org/linux-i3c/20201111220510.3622216-3-nico@fluxnic.net