diff options
Diffstat (limited to 'drivers/tty/serial')
| -rw-r--r-- | drivers/tty/serial/8250/8250_mtk.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c index 959fd85310bf..417c7c810df9 100644 --- a/drivers/tty/serial/8250/8250_mtk.c +++ b/drivers/tty/serial/8250/8250_mtk.c @@ -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; |