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Commit 195638b6 authored by Ji-Ze Hong (Peter Hong)'s avatar Ji-Ze Hong (Peter Hong) Committed by Greg Kroah-Hartman
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serial: 8250_fintek: UART dynamic clocksource on Fintek F81866 



The F81866 had 4 clocksource 1.8432/18.432/14.769/24MHz and baud rates can
be up to 1.5Mbits with 24MHz. We'll implements the dynamic clocksource in
fintek_8250_set_termios().

Signed-off-by: default avatarJi-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 3b837fa2

drivers/tty/serial/8250/8250_fintek.c

+54 −0
Original line number Diff line number Diff line
@@ -287,6 +287,59 @@ static void fintek_8250_goto_highspeed(struct uart_8250_port *uart, 
	}

}



void fintek_8250_set_termios(struct uart_port *port, struct ktermios *termios,

			struct ktermios *old)

{

	struct fintek_8250 *pdata = port->private_data;

	unsigned int baud = tty_termios_baud_rate(termios);

	int i;

	static u32 baudrate_table[] = {115200, 921600, 1152000, 1500000};

	static u8 clock_table[] = { F81866_UART_CLK_1_8432MHZ,

			F81866_UART_CLK_14_769MHZ, F81866_UART_CLK_18_432MHZ,

			F81866_UART_CLK_24MHZ };



	for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) {

		if (baud > baudrate_table[i] || baudrate_table[i] % baud != 0)

			continue;



		if (port->uartclk == baudrate_table[i] * 16)

			break;



		if (fintek_8250_enter_key(pdata->base_port, pdata->key))

			continue;



		port->uartclk = baudrate_table[i] * 16;



		sio_write_reg(pdata, LDN, pdata->index);

		sio_write_mask_reg(pdata, F81866_UART_CLK,

				F81866_UART_CLK_MASK, clock_table[i]);



		fintek_8250_exit_key(pdata->base_port);

		break;

	}



	if (i == ARRAY_SIZE(baudrate_table)) {

		baud = tty_termios_baud_rate(old);

		tty_termios_encode_baud_rate(termios, baud, baud);

	}



	serial8250_do_set_termios(port, termios, old);

}



static void fintek_8250_set_termios_handler(struct uart_8250_port *uart)

{

	struct fintek_8250 *pdata = uart->port.private_data;



	switch (pdata->pid) {

	case CHIP_ID_F81866:

		uart->port.set_termios = fintek_8250_set_termios;

		break;



	default:

		break;

	}

}



static int probe_setup_port(struct fintek_8250 *pdata,

					struct uart_8250_port *uart)

{
@@ -373,6 +426,7 @@ int fintek_8250_probe(struct uart_8250_port *uart) 
	memcpy(pdata, &probe_data, sizeof(probe_data));

	uart->port.private_data = pdata;

	fintek_8250_set_rs485_handler(uart);

	fintek_8250_set_termios_handler(uart);



	return 0;

}