On Mon, Oct 04, 2021 at 07:32:15PM -0500, minyard@xxxxxxx wrote: > From: Corey Minyard <cminyard@xxxxxxxxxx> > > The I2C slave interface expects that the driver will read ahead one > byte. The IMX driver/device doesn't do this, but simulate it so that > read operations get their index set correctly. > > Signed-off-by: Corey Minyard <minyard@xxxxxxx> > Tested-by: Andrew Manley <andrew.manley@xxxxxxxxxxxxxxx> > Reviewed-by: Andrew Manley <andrew.manley@xxxxxxxxxxxxxxx> Reviewed-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx> > --- > drivers/i2c/busses/i2c-imx.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c > index 97369fe48b30..26a04dc0590b 100644 > --- a/drivers/i2c/busses/i2c-imx.c > +++ b/drivers/i2c/busses/i2c-imx.c > @@ -769,6 +769,15 @@ static irqreturn_t i2c_imx_slave_handle(struct imx_i2c_struct *i2c_imx, > ctl &= ~I2CR_MTX; > imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR); > imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); > + > + /* > + * The i2c slave interface requires one extra dummy > + * read at the end to keep things in line. See the > + * I2C slave docs for details. > + */ > + i2c_imx_slave_event(i2c_imx, > + I2C_SLAVE_READ_PROCESSED, &value); > + > i2c_imx_slave_finish_op(i2c_imx); > return IRQ_HANDLED; > } > -- > 2.25.1 > > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
