Hello. Please discard this patch aside for a while. I'll check it again. Thanks! пт, 10 янв. 2025 г. в 13:28, Alexander Shiyan <eagle.alexander923@xxxxxxxxx>: > > The current driver version does not work for me on SAMA5D2 SOC. > I2C bus devices probing always returns good state, and as a result all > addresses 0x01-0x7f are always present. > After a some digging into the driver, I found that the NACK bit is not > handled correctly. I also found another SAMA5D2-related patch in the kernel > tree (1). > The result is a complex patch for correct I2C bus operation on SAMA5D2 SOC. > > [1] https://squing.com/lander/squing.com/?l=linux-i2c&m=156382173106314&w=3&_=%2F%23wXPKnebvZEv31W5L%2FkOlGQ%3D%3D > > Signed-off-by: Alexander Shiyan <eagle.alexander923@xxxxxxxxx> > --- > drivers/i2c/busses/i2c-at91.c | 14 +++++++++----- > 1 file changed, 9 insertions(+), 5 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-at91.c b/drivers/i2c/busses/i2c-at91.c > index dbc5aa4ddf..fb0a922a62 100644 > --- a/drivers/i2c/busses/i2c-at91.c > +++ b/drivers/i2c/busses/i2c-at91.c > @@ -113,7 +113,8 @@ static void at91_twi_write(struct at91_twi_dev *dev, unsigned reg, unsigned val) > static void at91_disable_twi_interrupts(struct at91_twi_dev *dev) > { > at91_twi_write(dev, AT91_TWI_IDR, > - AT91_TWI_TXCOMP | AT91_TWI_RXRDY | AT91_TWI_TXRDY); > + AT91_TWI_TXCOMP | AT91_TWI_RXRDY | > + AT91_TWI_TXRDY | AT91_TWI_NACK); > } > > static void at91_init_twi_bus(struct at91_twi_dev *dev) > @@ -223,8 +224,10 @@ static void at91_twi_write_next_byte(struct at91_twi_dev *dev) > at91_twi_write(dev, AT91_TWI_THR, *dev->buf); > > /* send stop when last byte has been written */ > - if (--dev->buf_len == 0) > + if (--dev->buf_len == 0) { > at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_STOP); > + at91_twi_write(dev, AT91_TWI_IDR, AT91_TWI_TXRDY); > + } > > dev_dbg(dev->dev, "wrote 0x%x, to go %d\n", *dev->buf, dev->buf_len); > > @@ -276,7 +279,7 @@ static int at91_twi_wait_completion(struct at91_twi_dev *dev) > > dev->transfer_status |= status; > > - } while (!(at91_twi_read(dev, AT91_TWI_SR) & AT91_TWI_TXCOMP)); > + } while (!(status & AT91_TWI_TXCOMP)); > > at91_disable_twi_interrupts(dev); > > @@ -311,11 +314,12 @@ static int at91_do_twi_transfer(struct at91_twi_dev *dev) > at91_twi_write(dev, AT91_TWI_CR, start_flags); > > at91_twi_write(dev, AT91_TWI_IER, > - AT91_TWI_TXCOMP | AT91_TWI_RXRDY); > + AT91_TWI_TXCOMP | AT91_TWI_NACK | AT91_TWI_RXRDY); > } else { > at91_twi_write_next_byte(dev); > at91_twi_write(dev, AT91_TWI_IER, > - AT91_TWI_TXCOMP | AT91_TWI_TXRDY); > + AT91_TWI_TXCOMP | AT91_TWI_NACK | > + (dev->buf_len ? AT91_TWI_TXRDY : 0)); > } > > ret = at91_twi_wait_completion(dev); > -- > 2.39.1 >
