linux-stable.git/drivers/i3c/master, branch v6.8

i3c: master: cdns: Update maximum prescaler value for i2c clock

2024-01-07T23:51:36+00:00

As per the Cadence IP document fixed the I2C clock divider value limit from
16 bits instead of 10 bits. Without this change setting up the I2C clock to
low frequencies will not work as the prescaler value might be greater than
10 bit number.

I3C clock divider value is 10 bits only. Updating the macro names for both.

Signed-off-by: Harshit Shah 
Link: https://lore.kernel.org/r/1703927483-28682-1-git-send-email-harshitshah.opendev@gmail.com
Signed-off-by: Alexandre Belloni

i3c: master: svc: return actual transfer data len

2024-01-07T23:49:21+00:00

I3C allow devices early terminate data transfer. So set "actual_len" to
indicate how much data get by i3c_priv_xfer.

Reviewed-by: Miquel Raynal 
Signed-off-by: Frank Li 
Link: https://lore.kernel.org/r/20231201222532.2431484-6-Frank.Li@nxp.com
Signed-off-by: Alexandre Belloni

i3c: master: svc: rename read_len as actual_len

2024-01-07T23:49:21+00:00

I3C transfer (SDR), target can early terminate read transfer.
I3C transfer (HDR), target can end write transfer.
I2C transfer, target can NACK write transfer.

'actual_len' is better name than 'read_len'.

Reviewed-by: Miquel Raynal 
Signed-off-by: Frank Li 
Link: https://lore.kernel.org/r/20231201222532.2431484-5-Frank.Li@nxp.com
Signed-off-by: Alexandre Belloni

i3c: master: svc: add hot join support

2024-01-07T23:48:10+00:00

Add hot join support for svc master controller. Disable hot join by
default.
User can use sysfs entry to enable hot join.

Signed-off-by: Frank Li 
Link: https://lore.kernel.org/r/20231201222532.2431484-3-Frank.Li@nxp.com
Signed-off-by: Alexandre Belloni

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

2023-11-16T22:36:44+00:00

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 
Link: https://lore.kernel.org/r/20231109133708.653950-5-jarkko.nikula@linux.intel.com
Signed-off-by: Alexandre Belloni

i3c: mipi-i3c-hci: Handle I3C address header error in hci_cmd_v1_daa()

2023-11-16T22:36:44+00:00

Handle also I3C address header error response status as the end of DAA
process in hci_cmd_v1_daa().

According to MIPI I3C HCI Specification v1.1 the NACK error during DAA
process comes when the device does not accept the dynamic address.
Currently code uses it for successful exit from the process and fails
with any other error response.

I'm unsure is this MIPI I3C HCI version specific difference or
specification misunderstanding but on an early MIPI I3C HCI version
compatible controller responds always with I3C address header error and
not with NACK error when there is no device on the bus or no more devices
participating to DAA process.

Handle now both response statuses as the end of DAA.

Signed-off-by: Jarkko Nikula 
Link: https://lore.kernel.org/r/20231109133708.653950-4-jarkko.nikula@linux.intel.com
Signed-off-by: Alexandre Belloni

i3c: mipi-i3c-hci: Do not overallocate transfers in hci_cmd_v1_daa()

2023-11-16T22:36:44+00:00

Function hci_cmd_v1_daa() uses only single transfer at a time so no need
to allocate two transfers and access can be simplified.

Signed-off-by: Jarkko Nikula 
Link: https://lore.kernel.org/r/20231109133708.653950-3-jarkko.nikula@linux.intel.com
Signed-off-by: Alexandre Belloni

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

2023-11-16T22:36:44+00:00

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 
Link: https://lore.kernel.org/r/20231109133708.653950-2-jarkko.nikula@linux.intel.com
Signed-off-by: Alexandre Belloni

i3c: master: mipi-i3c-hci: Fix a kernel panic for accessing DAT_data.

2023-11-03T23:39:52+00:00

The `i3c_master_bus_init` function may attach the I2C devices before the
I3C bus initialization. In this flow, the DAT `alloc_entry`` will be used
before the DAT `init`. Additionally, if the `i3c_master_bus_init` fails,
the DAT `cleanup` will execute before the device is detached, which will
execue DAT `free_entry` function. The above scenario can cause the driver
to use DAT_data when it is NULL.

Signed-off-by: Billy Tsai 
Link: https://lore.kernel.org/r/20231023080237.560936-1-billy_tsai@aspeedtech.com
Signed-off-by: Alexandre Belloni

i3c: master: svc: fix compatibility string mismatch with binding doc

2023-11-03T19:02:45+00:00

In the binding documentation, the compatible string is specified as
'silvaco,i3c-master-v1', but in the driver, it is defined as
'silvaco,i3c-master'.

Rename 'silvaco,i3c-master' to 'silvaco,i3c-master-v1' to ensure
compatibility with the documentation.

Signed-off-by: Frank Li 
Link: https://lore.kernel.org/r/20231017194657.3199749-1-Frank.Li@nxp.com
Signed-off-by: Alexandre Belloni