Hi Biju, On Thu, Feb 9, 2023 at 2:30 PM Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote: > As per HW manual section 40.6.1, we need to perform FIFO reset + SW > reset before updating the below registers > > FCR[7:5], FCR[3:0], LCR[7][5:0], MCR[6:4], DLL[7:0], DLM[7:0] and > HCR0[6:5][3:2]. > > This patch adds serial8250_rzv2m_reg_update() to handle it. > > DLL/DLM register can be updated only by setting LCR[7]. So the > updation of LCR[7] will perform reset for DLL/DLM register changes. > > Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx> Thanks for your patch! > --- a/drivers/tty/serial/8250/8250_em.c > +++ b/drivers/tty/serial/8250/8250_em.c > @@ -111,6 +156,10 @@ static int serial8250_em_probe(struct platform_device *pdev) > up.port.uartclk = clk_get_rate(priv->sclk); > > up.port.iotype = UPIO_MEM32; > + > + if (of_device_is_compatible(dev->of_node, "renesas,r9a09g011-uart")) > + priv->is_rzv2m = true; Please add an entry to serial8250_em_dt_ids[] instead, providing a feature flag in of_device_id.data. > + > up.port.serial_in = serial8250_em_serial_in; > up.port.serial_out = serial8250_em_serial_out; > up.dl_read = serial8250_em_serial_dl_read; Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds