Messages in this thread | ![/](/images/icornerl.gif) | | Date | Fri, 11 Nov 2022 18:42:07 +0200 | From | Andy Shevchenko <> | Subject | Re: [PATCH v4 tty-next 2/3] 8250: microchip: pci1xxxx: Add rs485 support to quad-uart driver |
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On Fri, Nov 11, 2022 at 09:41:29PM +0530, Kumaravel Thiagarajan wrote: > pci1xxxx uart supports rs485 mode of operation in the hardware with
UART RS485 (same in the subject)
> auto-direction control with configurable delay for releasing RTS after > the transmission. This patch adds support for the rs485 mode.
RS485
...
> Signed-off-by: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com> > Signed-off-by: Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com>
No Co-developed-by?
...
> +static int pci1xxxx_rs485_config(struct uart_port *port, > + struct ktermios *termios, > + struct serial_rs485 *rs485) > +{ > + u32 clock_div = readl(port->membase + UART_BAUD_CLK_DIVISOR_REG);
> + u8 delay_in_baud_periods = 0; > + u32 baud_period_in_ns = 0;
Why these assignments?
> + u32 data = 0; > + > + /* pci1xxxx's uart hardware supports only RTS delay after > + * Tx and in units of bit times to a maximum of 15 > + */
/* * Use proper multi-line * comment style. */
> + if (rs485->flags & SER_RS485_ENABLED) { > + data = ADCL_CFG_EN | ADCL_CFG_PIN_SEL; > + > + if (!(rs485->flags & SER_RS485_RTS_ON_SEND)) > + data |= ADCL_CFG_POL_SEL; > + > + if (rs485->delay_rts_after_send) { > + baud_period_in_ns = > + FIELD_GET(BAUD_CLOCK_DIV_INT_MSK, clock_div) * > + UART_BIT_SAMPLE_CNT; > + delay_in_baud_periods = > + (rs485->delay_rts_after_send * NSEC_PER_MSEC) / > + baud_period_in_ns; > + delay_in_baud_periods = > + min_t(u8, delay_in_baud_periods, > + FIELD_MAX(ADCL_CFG_RTS_DELAY_MASK)); > + data |= FIELD_PREP(ADCL_CFG_RTS_DELAY_MASK, > + delay_in_baud_periods); > + rs485->delay_rts_after_send = > + (baud_period_in_ns * delay_in_baud_periods) / > + NSEC_PER_MSEC; > + rs485->delay_rts_before_send = 0; > + } > + } > + writel(data, port->membase + ADCL_CFG_REG); > + return 0; > +}
-- With Best Regards, Andy Shevchenko
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