root/arch/sh/kernel/cpu/sh3/serial-sh770x.c
// SPDX-License-Identifier: GPL-2.0
#include <linux/serial_sci.h>
#include <linux/serial_core.h>
#include <linux/io.h>
#include <cpu/serial.h>

#define SCPCR 0xA4000116
#define SCPDR 0xA4000136

static void sh770x_sci_init_pins(struct uart_port *port, unsigned int cflag)
{
        unsigned short data;

        /* We need to set SCPCR to enable RTS/CTS */
        data = __raw_readw(SCPCR);
        /* Clear out SCP7MD1,0, SCP6MD1,0, SCP4MD1,0*/
        __raw_writew(data & 0x0fcf, SCPCR);

        if (!(cflag & CRTSCTS)) {
                /* We need to set SCPCR to enable RTS/CTS */
                data = __raw_readw(SCPCR);
                /* Clear out SCP7MD1,0, SCP4MD1,0,
                   Set SCP6MD1,0 = {01} (output)  */
                __raw_writew((data & 0x0fcf) | 0x1000, SCPCR);

                data = __raw_readb(SCPDR);
                /* Set /RTS2 (bit6) = 0 */
                __raw_writeb(data & 0xbf, SCPDR);
        }
}

struct plat_sci_port_ops sh770x_sci_port_ops = {
        .init_pins      = sh770x_sci_init_pins,
};