In an In-Band Interrupt (IBI) handle, the code logic is as follows:
1: writel(SVC_I3C_MCTRL_REQUEST_AUTO_IBI | SVC_I3C_MCTRL_IBIRESP_AUTO,
master->regs + SVC_I3C_MCTRL);
2: ret = readl_relaxed_poll_timeout(master->regs + SVC_I3C_MSTATUS, val,
SVC_I3C_MSTATUS_IBIWON(val), 0, 1000);
...
3: ibitype = SVC_I3C_MSTATUS_IBITYPE(status);
ibiaddr = SVC_I3C_MSTATUS_IBIADDR(status);
SVC_I3C_MSTATUS_IBIWON may be set before step 1. Thus, step 2 will return
immediately, and the I3C controller has not sent out the 9th SCL yet.
Consequently, ibitype and ibiaddr are 0, resulting in an unknown IBI type
occurrence and missing call I3C client driver's IBI handler.
A typical case is that SVC_I3C_MSTATUS_IBIWON is set when an IBI occurs
during the controller send start frame in svc_i3c_master_xfer().
Clear SVC_I3C_MSTATUS_IBIWON before issue SVC_I3C_MCTRL_REQUEST_AUTO_IBI
to fix this issue.
Cc: stable@vger.kernel.org
Fixes: 5e5e3c92e7 ("i3c: master: svc: fix wrong data return when IBI happen during start frame")
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20240506164009.21375-3-Frank.Li@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
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: dd3c52846d ("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>
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: dd3c52846d ("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>
┌─────┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┌─────
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: dd3c52846d ("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 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: dd3c52846d ("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>
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>
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
