i3c: master: svc: return actual transfer data len

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 <miquel.raynal@bootlin.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20231201222532.2431484-6-Frank.Li@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

i3c: master: svc: rename read_len as actual_len

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 <miquel.raynal@bootlin.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20231201222532.2431484-5-Frank.Li@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

i3c: master: svc: add hot join support

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

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

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

i3c: master: svc: fix random hot join failure since timeout error

master side report:
silvaco-i3c-master 44330000.i3c-master: Error condition: MSTATUS 0x020090c7, MERRWARN 0x00100000

BIT 20: TIMEOUT error
The module has stalled too long in a frame. This happens when:
- The TX FIFO or RX FIFO is not handled and the bus is stuck in the
middle of a message,
- No STOP was issued and between messages,
- IBI manual is used and no decision was made.
The maximum stall period is 100 μs.

This can be considered as being just a warning as the system IRQ latency
can easily be greater than 100us.

Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
Cc: <stable@vger.kernel.org>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20231023161658.3890811-7-Frank.Li@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

i3c: master: svc: fix SDA keep low when polling IBIWON timeout happen

Upon IBIWON timeout, the SDA line will always be kept low if we don't emit
a stop. Calling svc_i3c_master_emit_stop() there will let the bus return to
idle state.

Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
Cc: <stable@vger.kernel.org>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20231023161658.3890811-6-Frank.Li@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

i3c: master: svc: fix check wrong status register in irq handler

svc_i3c_master_irq_handler() wrongly checks register SVC_I3C_MINTMASKED. It
should be SVC_I3C_MSTATUS.

Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
Cc: <stable@vger.kernel.org>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20231023161658.3890811-5-Frank.Li@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

i3c: master: svc: fix ibi may not return mandatory data byte

MSTATUS[RXPEND] is only updated after the data transfer cycle started. This
creates an issue when the I3C clock is slow, and the CPU is running fast
enough that MSTATUS[RXPEND] may not be updated when the code reaches
checking point. As a result, mandatory data can be missed.

Add a wait for MSTATUS[COMPLETE] to ensure that all mandatory data is
already in FIFO. It also works without mandatory data.

Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
Cc: <stable@vger.kernel.org>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20231023161658.3890811-4-Frank.Li@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

i3c: master: svc: fix wrong data return when IBI happen during start frame

┌─────┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┌─────
SCL: ┘ └─────┛ └──┛ └──┛ └──┛ └──┛ └──┛ └──┛ └──┛ └──┘
───┐ ┌─────┐ ┌─────┐ ┌───────────┐
SDA: └───────────────────────┘ └─────┘ └─────┘ └─────
xxx╱ ╲╱ ╲╱ ╲╱ ╲╱ ╲
: xxx╲IBI ╱╲ Addr(0x0a) ╱╲ RW ╱╲NACK╱╲ S ╱

If an In-Band Interrupt (IBI) occurs and IBI work thread is not immediately
scheduled, when svc_i3c_master_priv_xfers() initiates the I3C transfer and
attempts to send address 0x7e, the target interprets it as an
IBI handler and returns the target address 0x0a.

However, svc_i3c_master_priv_xfers() does not handle this case and proceeds
with other transfers, resulting in incorrect data being returned.

Add IBIWON check in svc_i3c_master_xfer(). In case this situation occurs,
return a failure to the driver.

Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
Cc: <stable@vger.kernel.org>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20231023161658.3890811-3-Frank.Li@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

i3c: master: svc: fix race condition in ibi work thread

The ibi work thread operates asynchronously with other transfers, such as
svc_i3c_master_priv_xfers(). Introduce mutex protection to ensure the
completion of the entire i3c/i2c transaction.

Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
Cc: <stable@vger.kernel.org>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20231023161658.3890811-2-Frank.Li@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

i3c: Fix typo "Provisional ID" to "Provisioned ID"

The MIPI I3C spec refers to a Provisioned ID, since it is (sometimes)
provisioned at device manufacturing.

Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20231003075339.197099-1-matt@codeconstruct.com.au
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

i3c: svc: Annotate struct svc_i3c_xfer with __counted_by

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct svc_i3c_xfer.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Conor Culhane <conor.culhane@silvaco.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: linux-i3c@lists.infradead.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20230922175023.work.239-kees@kernel.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

i3c: master: svc: fix probe failure when no i3c device exist

I3C masters are expected to support hot-join. This means at initialization
time we might not yet discover any device and this should not be treated
as a fatal error.

During the DAA procedure which happens at probe time, if no device has
joined, all CCC will be NACKed (from a bus perspective). This leads to an
early return with an error code which fails the probe of the master.

Let's avoid this by just telling the core through an I3C_ERROR_M2
return command code that no device was discovered, which is a valid
situation. This way the master will no longer bail out and fail to probe
for a wrong reason.

Cc: stable@vger.kernel.org
Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20230831141324.2841525-1-Frank.Li@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

i3c: master: svc: Describe member 'saved_regs'

The 'saved_regs' member of the 'svc_i3c_master' structure is not
described in the kernel doc, which produces the following warning:

Function parameter or member 'saved_regs' not described in 'svc_i3c_master'

Add the missing line in the kernel documentation of the parent
structure.

Fixes: 1c5ee2a77b1b ("i3c: master: svc: fix i3c suspend/resume issue")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202308171435.0xQ82lvu-lkp@intel.com/
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20230817101853.16805-1-miquel.raynal@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

i3c: master: svc: Do not check for 0 return after calling platform_get_irq()

It is not possible for platform_get_irq() to return 0. Use the
return value from platform_get_irq().

Signed-off-by: Ruan Jinjie <ruanjinjie@huawei.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20230803085149.149248-1-ruanjinjie@huawei.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

i3c: master: svc: add NACK check after start byte sent

Add NACK check after start byte is sent.
It is possible to detect early that a device is not on the bus
and avoid invalid transmissions thereafter.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20230517033030.3068085-3-xiaoning.wang@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

i3c: master: svc: fix cpu schedule in spin lock

pm_runtime_resume_and_get() may call sleep(). It cannot be used in
svc_i3c_master_start_xfer_locked(), because it is in a spin lock.

Move the pm runtime operations to svc_i3c_master_enqueue_xfer().

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Fixes: 05be23ef78f7 ("i3c: master: svc: add runtime pm support")
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20230517033030.3068085-2-xiaoning.wang@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

i3c: master: svc: fix i3c suspend/resume issue

When system suspends, if i3c module is powered down, register
value will lose.
Need to save the key registers before system suspend.
So save these registers value in runtime pm suspend, and restore them
if these register's value is different with the saved values
when runtime pm resume.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20230517033030.3068085-1-xiaoning.wang@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

i3c: svc: 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>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20230318233311.265186-6-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: svc: fix returnvar.cocci warning

Fix the following coccicheck warning:

drivers/i3c/master/svc-i3c-master.c:1600:5-8:
Unneeded variable: "ret". Return "0" on line 1605.

Signed-off-by: Guo Zhengkui <guozhengkui@vivo.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220504164901.9622-1-guozhengkui@vivo.com

i3c: master: svc: enable the interrupt in the enable ibi function

If enable interrupt in the svc_i3c_master_bus_init() but do not call
enable ibi in the device driver, it will cause a kernel dump in the
svc_i3c_master_handle_ibi() when a slave start occurs on the i3c bus,
because the data->ibi_pool is not initialized.
So only enable the interrupt in svc_i3c_master_enable_ibi() function.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211227074529.1660398-9-xiaoning.wang@nxp.com

i3c: master: svc: add the missing module device table

The missing MODULE_DEVICE_TABLE() will cause the svc-i3c-master cannot
be auto probed when it is built in moudle.
So add it.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Jun Li <jun.li@nxp.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211227074529.1660398-8-xiaoning.wang@nxp.com

i3c: master: svc: add runtime pm support

Add runtime pm support to dynamically manage the clock.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Jun Li <jun.li@nxp.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211227074529.1660398-7-xiaoning.wang@nxp.com

i3c: master: svc: set ODSTOP to let I2C device see the STOP signal

If using I2C/I3C mixed mode, need to set ODSTOP. Otherwise, the I2C
devices cannot see the stop signal. It may cause message sending errors.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Jun Li <jun.li@nxp.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211227074529.1660398-6-xiaoning.wang@nxp.com

i3c: master: svc: add support for slave to stop returning data

When i3c controller reads data from slave device, slave device can stop
returning data with an ACK after any byte.
Add this support for svc i3c controller. Otherwise, it will timeout
when the slave device ends the read operation early.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Reviewed-by: Jun Li <jun.li@nxp.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211227074529.1660398-5-xiaoning.wang@nxp.com

i3c: master: svc: separate err, fifo and disable interrupt of reset function

Sometimes only need to reset err and fifo regs, so split the origin
reset function to three functions.
Put them at the top of the file, to let more functions can call them.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Jun Li <jun.li@nxp.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211227074529.1660398-4-xiaoning.wang@nxp.com

i3c: master: svc: fix atomic issue

do_daa_locked() function is in a spin lock environment, use
readl_poll_timeout_atomic() to replace the origin
readl_poll_timeout().

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Jun Li <jun.li@nxp.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211227074529.1660398-3-xiaoning.wang@nxp.com

i3c: master: svc: move module reset behind clk enable

Reset I3C module will R/W its regs, so enable its clocks first.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Jun Li <jun.li@nxp.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211227074529.1660398-2-xiaoning.wang@nxp.com

i3c: master: svc: fix doc warning in svc-i3c-master.c

Fix the following make W=1 warning:

drivers/i3c/master/svc-i3c-master.c:207: warning: expecting prototype for struct svc_i3c_i3c_dev_data. Prototype was for struct svc_i3c_i2c_dev_data instead

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210602085544.4101980-1-yangyingliang@huawei.com

i3c: master: svc: drop free_irq of devm_request_irq allocated irq

irq allocated with devm_request_irq() will be freed in devm_irq_release(),
using free_irq() in ->remove() will causes a dangling pointer, and a
subsequent double free. So remove the free_irq() in svc_i3c_master_remove().

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210602084935.3977636-1-yangyingliang@huawei.com

i3c: master: svc: remove redundant assignment to cmd->read_len

The assignment of xfer_len to cmd->read_len appears to be redundant
as the next statement re-assigns the value 0 to it. Clean up the
code by removing the redundant first assignment.

Addresses-Coverity: ("Unused value")
Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210224151349.202332-1-colin.king@canonical.com

i3c: master: svc: Add Silvaco I3C master driver

Add support for Silvaco I3C dual-role IP. The master role is supported
in SDR mode only. I2C transfers have not been tested but are shared
because they are very close to the I3C transfers in terms of register
configuration.

The IBI processing follows this logic:
- When a slave advertizes an interrupt (SDA pulled low) an interrupt
gets generated by the master. This time is unbounded and may be
deferred.
- The IRQ handler itself does not process anything: it only queues a
work that will be run in non-atomic context. This is needed because
short wait periods must be experienced.
- The IBI job is divided in two parts: the first one is "critical" in
the sense that it may not support getting interrupted. If this
happens, after this first section the driver checks the master error
register and depending on its content either flushes everything and
errors out, or ends the processing (this second section may be
interrupted).
- If the critical section got interrupted, the slave will
automatically respin it's IBI request when it will be allowed to.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210121101808.14654-6-miquel.raynal@bootlin.com