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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>
This commit is contained in:
Clark Wang 2023-05-17 11:30:30 +08:00 committed by Alexandre Belloni
parent 33beadb3b1
commit 49b472ebc6
1 changed files with 6 additions and 0 deletions
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6
drivers/i3c/master/svc-i3c-master.c
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@ -92,6 +92,7 @@
#define SVC_I3C_MINTCLR 0x094
#define SVC_I3C_MINTMASKED 0x098
#define SVC_I3C_MERRWARN 0x09C
#define SVC_I3C_MERRWARN_NACK BIT(2)
#define SVC_I3C_MDMACTRL 0x0A0
#define SVC_I3C_MDATACTRL 0x0AC
#define SVC_I3C_MDATACTRL_FLUSHTB BIT(0)
@ -1014,6 +1015,11 @@ static int svc_i3c_master_xfer(struct svc_i3c_master *master,
if (ret)
goto emit_stop;
if (readl(master->regs + SVC_I3C_MERRWARN) & SVC_I3C_MERRWARN_NACK) {
ret = -ENXIO;
goto emit_stop;
}
if (rnw)
ret = svc_i3c_master_read(master, in, xfer_len);
else