Re: [PATCH 4/4] i3c: master: svc: set ODSTOP to let I2C device see the STOP signal

Miquel Raynal
2021-07-15T22:57:44Z

Hi Clark,

Clark Wang <xiaoning.wang@nxp.com> wrote on Thu, 15 Jul 2021 16:24:13
+0800:

> 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.

Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>

>
> Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
> ---
> drivers/i3c/master/svc-i3c-master.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
> index 892e57fec4b0..b05cc7f521e6 100644
> --- a/drivers/i3c/master/svc-i3c-master.c
> +++ b/drivers/i3c/master/svc-i3c-master.c
> @@ -449,7 +449,7 @@ static int svc_i3c_master_bus_init(struct i3c_master_controller *m)
> struct i3c_device_info info = {};
> unsigned long fclk_rate, fclk_period_ns;
> unsigned int high_period_ns, od_low_period_ns;
> - u32 ppbaud, pplow, odhpp, odbaud, i2cbaud, reg;
> + u32 ppbaud, pplow, odhpp, odbaud, odstop, i2cbaud, reg;
> int ret;
>
> /* Timings derivation */
> @@ -479,6 +479,7 @@ static int svc_i3c_master_bus_init(struct i3c_master_controller *m)
> switch (bus->mode) {
> case I3C_BUS_MODE_PURE:
> i2cbaud = 0;
> + odstop = 0;
> break;
> case I3C_BUS_MODE_MIXED_FAST:
> case I3C_BUS_MODE_MIXED_LIMITED:
> @@ -487,6 +488,7 @@ static int svc_i3c_master_bus_init(struct i3c_master_controller *m)
> * between the high and low period does not really matter.
> */
> i2cbaud = DIV_ROUND_UP(1000, od_low_period_ns) - 2;
> + odstop = 1;
> break;
> case I3C_BUS_MODE_MIXED_SLOW:
> /*
> @@ -494,6 +496,7 @@ static int svc_i3c_master_bus_init(struct i3c_master_controller *m)
> * constraints as the FM+ mode.
> */
> i2cbaud = DIV_ROUND_UP(2500, od_low_period_ns) - 2;
> + odstop = 1;
> break;
> default:
> return -EINVAL;
> @@ -502,7 +505,7 @@ static int svc_i3c_master_bus_init(struct i3c_master_controller *m)
> reg = SVC_I3C_MCONFIG_MASTER_EN |
> SVC_I3C_MCONFIG_DISTO(0) |
> SVC_I3C_MCONFIG_HKEEP(0) |
> - SVC_I3C_MCONFIG_ODSTOP(0) |
> + SVC_I3C_MCONFIG_ODSTOP(odstop) |
> SVC_I3C_MCONFIG_PPBAUD(ppbaud) |
> SVC_I3C_MCONFIG_PPLOW(pplow) |
> SVC_I3C_MCONFIG_ODBAUD(odbaud) |

Thanks,
Miquèl