Hi Jiri Slaby and Ilpo, Thanks for feedback. > Subject: Re: [PATCH v3 3/3] serial: 8250_em: Add serial_out() to struct > serial8250_em_hw_info > > On 13. 02. 23, 10:12, Jiri Slaby wrote: > > On 13. 02. 23, 10:10, Jiri Slaby wrote: > >> On 13. 02. 23, 9:53, Biju Das wrote: > >>>>> +static void serial8250_rzv2m_reg_update(struct uart_port *p, int > >>>>> +off, int value) { > >>>>> + unsigned int ier, fcr, lcr, mcr, hcr0; > >>>>> + > >>>>> + ier = serial8250_em_serial_in(p, UART_IER); > >>>>> + lcr = serial8250_em_serial_in(p, UART_LCR); > >>>>> + mcr = serial8250_em_serial_in(p, UART_MCR); > >>>>> + hcr0 = serial8250_em_serial_in(p, UART_HCR0); > >>>>> + /* > >>>>> + * The value of UART_IIR and UART_FCR are 2, but > >>>>> +corresponding > >>>>> + * RZ/V2M address offset are different(0x08 and 0x0c). So we > >>>>> need to > >>>>> + * use readl() here. > >>>>> + */ > >>>>> + fcr = readl(p->membase + ((UART_FCR + 1) << 2)); > >>>> > >>>> I don't get the meaning of that comment. It doesn't seem to match > >>>> what your code does as the code seemingly has nothing to do with > >>>> IIR (and none of you changelogs refer to IIR either)? > >>> > >>> The generic macro UART_IIR and UART_FCR in linux/serial_reg.h has a > >>> value of 2. > >> > >> Sure, IIR is normally WO and FCR RO > > What was I thinking? Switch that WO and RO, of course. > > > and share the same register. I > >> would simply define UART_FCR_RZ (or alike) > > > > Or even UART_FCR_RO_RZ? > > > >> for 0x12. > > > > I mean 12 or 0xc. As per Geert, "According to R19UH0040EJ0400 Rev.4.00 it is available on EMEV2, and the layout looks identical to RZ/V2M." Adding Magnus and Niklas to test on EMMA mobile platform to check the port type detected On that platform? So looks like similar to other macros, UART_FCR_EM (0x3) is sensible one. UART_FCR_RO_OFFSET (9) UART_FCR_RO_EM (UART_FCR_EM + UART_FCR_RO_OFFSET) static unsigned int serial8250_em_serial_in(struct uart_port *p, int offset) case UART_FCR_RO_EM: return readl(p->membase + (offset - UART_FCR_RO_OFFSET << 2)); Cheers, Biju