Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit bdbd0a7f authored by Long Cheng's avatar Long Cheng Committed by Greg Kroah-Hartman
Browse files

serial: 8250-mtk: modify baudrate setting 



In termios function, add Fractional divider to adjust baudrate.

Signed-off-by: default avatarLong Cheng <long.cheng@mediatek.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 8ceeb470

drivers/tty/serial/8250/8250_mtk.c

+102 −0
Original line number Diff line number Diff line
@@ -25,13 +25,28 @@ 
#define MTK_UART_SAMPLE_COUNT	0x0a	/* Sample count register */

#define MTK_UART_SAMPLE_POINT	0x0b	/* Sample point register */

#define MTK_UART_RATE_FIX	0x0d	/* UART Rate Fix Register */

#define MTK_UART_ESCAPE_DAT	0x10	/* Escape Character register */

#define MTK_UART_ESCAPE_EN	0x11	/* Escape Enable register */

#define MTK_UART_DMA_EN		0x13	/* DMA Enable register */

#define MTK_UART_RXTRI_AD	0x14	/* RX Trigger address */

#define MTK_UART_FRACDIV_L	0x15	/* Fractional divider LSB address */

#define MTK_UART_FRACDIV_M	0x16	/* Fractional divider MSB address */

#define MTK_UART_IER_XOFFI	0x20	/* Enable XOFF character interrupt */

#define MTK_UART_IER_RTSI	0x40	/* Enable RTS Modem status interrupt */

#define MTK_UART_IER_CTSI	0x80	/* Enable CTS Modem status interrupt */



#define MTK_UART_EFR_EN		0x10	/* Enable enhancement feature */

#define MTK_UART_EFR_RTS	0x40	/* Enable hardware rx flow control */

#define MTK_UART_EFR_CTS	0x80	/* Enable hardware tx flow control */

#define MTK_UART_EFR_NO_SW_FC	0x0	/* no sw flow control */

#define MTK_UART_EFR_XON1_XOFF1	0xa	/* XON1/XOFF1 as sw flow control */

#define MTK_UART_EFR_XON2_XOFF2	0x5	/* XON2/XOFF2 as sw flow control */

#define MTK_UART_EFR_SW_FC_MASK	0xf	/* Enable CTS Modem status interrupt */

#define MTK_UART_EFR_HW_FC	(MTK_UART_EFR_RTS | MTK_UART_EFR_CTS)

#define MTK_UART_DMA_EN_TX	0x2

#define MTK_UART_DMA_EN_RX	0x5



#define MTK_UART_ESCAPE_CHAR	0x77	/* Escape char added under sw fc */

#define MTK_UART_TX_SIZE	UART_XMIT_SIZE

#define MTK_UART_RX_SIZE	0x8000

#define MTK_UART_TX_TRIGGER	1
@@ -57,6 +72,13 @@ struct mtk8250_data { 
#endif

};



/* flow control mode */

enum {

	MTK_UART_FC_NONE,

	MTK_UART_FC_SW,

	MTK_UART_FC_HW,

};



#ifdef CONFIG_SERIAL_8250_DMA

static void mtk8250_rx_dma(struct uart_8250_port *up);
@@ -195,6 +217,75 @@ static void mtk8250_shutdown(struct uart_port *port) 
	return serial8250_do_shutdown(port);

}



static void mtk8250_disable_intrs(struct uart_8250_port *up, int mask)

{

	serial_out(up, UART_IER, serial_in(up, UART_IER) & (~mask));

}



static void mtk8250_enable_intrs(struct uart_8250_port *up, int mask)

{

	serial_out(up, UART_IER, serial_in(up, UART_IER) | mask);

}



static void mtk8250_set_flow_ctrl(struct uart_8250_port *up, int mode)

{

	struct uart_port *port = &up->port;

	int lcr = serial_in(up, UART_LCR);



	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);

	serial_out(up, UART_EFR, UART_EFR_ECB);

	serial_out(up, UART_LCR, lcr);

	lcr = serial_in(up, UART_LCR);



	switch (mode) {

	case MTK_UART_FC_NONE:

		serial_out(up, MTK_UART_ESCAPE_DAT, MTK_UART_ESCAPE_CHAR);

		serial_out(up, MTK_UART_ESCAPE_EN, 0x00);

		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);

		serial_out(up, UART_EFR, serial_in(up, UART_EFR) &

			(~(MTK_UART_EFR_HW_FC | MTK_UART_EFR_SW_FC_MASK)));

		serial_out(up, UART_LCR, lcr);

		mtk8250_disable_intrs(up, MTK_UART_IER_XOFFI |

			MTK_UART_IER_RTSI | MTK_UART_IER_CTSI);

		break;



	case MTK_UART_FC_HW:

		serial_out(up, MTK_UART_ESCAPE_DAT, MTK_UART_ESCAPE_CHAR);

		serial_out(up, MTK_UART_ESCAPE_EN, 0x00);

		serial_out(up, UART_MCR, UART_MCR_RTS);

		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);



		/*enable hw flow control*/

		serial_out(up, UART_EFR, MTK_UART_EFR_HW_FC |

			(serial_in(up, UART_EFR) &

			(~(MTK_UART_EFR_HW_FC | MTK_UART_EFR_SW_FC_MASK))));



		serial_out(up, UART_LCR, lcr);

		mtk8250_disable_intrs(up, MTK_UART_IER_XOFFI);

		mtk8250_enable_intrs(up, MTK_UART_IER_CTSI | MTK_UART_IER_RTSI);

		break;



	case MTK_UART_FC_SW:	/*MTK software flow control */

		serial_out(up, MTK_UART_ESCAPE_DAT, MTK_UART_ESCAPE_CHAR);

		serial_out(up, MTK_UART_ESCAPE_EN, 0x01);

		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);



		/*enable sw flow control */

		serial_out(up, UART_EFR, MTK_UART_EFR_XON1_XOFF1 |

			(serial_in(up, UART_EFR) &

			(~(MTK_UART_EFR_HW_FC | MTK_UART_EFR_SW_FC_MASK))));



		serial_out(up, UART_XON1, START_CHAR(port->state->port.tty));

		serial_out(up, UART_XOFF1, STOP_CHAR(port->state->port.tty));

		serial_out(up, UART_LCR, lcr);

		mtk8250_disable_intrs(up, MTK_UART_IER_CTSI|MTK_UART_IER_RTSI);

		mtk8250_enable_intrs(up, MTK_UART_IER_XOFFI);

		break;

	default:

		break;

	}

}



static void

mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,

			struct ktermios *old)
@@ -208,6 +299,7 @@ mtk8250_set_termios(struct uart_port *port, struct ktermios *termios, 
	struct uart_8250_port *up = up_to_u8250p(port);

	unsigned int baud, quot, fraction;

	unsigned long flags;

	int mode;



#ifdef CONFIG_SERIAL_8250_DMA

	if (up->dma) {
@@ -281,6 +373,16 @@ mtk8250_set_termios(struct uart_port *port, struct ktermios *termios, 
		serial_port_out(port, MTK_UART_FRACDIV_L, 0x00);

		serial_port_out(port, MTK_UART_FRACDIV_M, 0x00);

	}



	if ((termios->c_cflag & CRTSCTS) && (!(termios->c_iflag & CRTSCTS)))

		mode = MTK_UART_FC_HW;

	else if (termios->c_iflag & CRTSCTS)

		mode = MTK_UART_FC_SW;

	else

		mode = MTK_UART_FC_NONE;



	mtk8250_set_flow_ctrl(up, mode);



	if (uart_console(port))

		up->port.cons->cflag = termios->c_cflag;