diff options
| -rw-r--r-- | drivers/serial/amba-pl011.c | 27 | ||||
| -rw-r--r-- | include/linux/amba/serial.h | 1 |
2 files changed, 26 insertions, 2 deletions
diff --git a/drivers/serial/amba-pl011.c b/drivers/serial/amba-pl011.c index 5644cf2385bb..f67e09da6d33 100644 --- a/drivers/serial/amba-pl011.c +++ b/drivers/serial/amba-pl011.c @@ -74,6 +74,7 @@ struct uart_amba_port { unsigned int ifls; /* vendor-specific */ unsigned int lcrh_tx; /* vendor-specific */ unsigned int lcrh_rx; /* vendor-specific */ + bool oversampling; /* vendor-specific */ bool autorts; }; @@ -83,6 +84,7 @@ struct vendor_data { unsigned int fifosize; unsigned int lcrh_tx; unsigned int lcrh_rx; + bool oversampling; }; static struct vendor_data vendor_arm = { @@ -90,6 +92,7 @@ static struct vendor_data vendor_arm = { .fifosize = 16, .lcrh_tx = UART011_LCRH, .lcrh_rx = UART011_LCRH, + .oversampling = false, }; static struct vendor_data vendor_st = { @@ -97,6 +100,7 @@ static struct vendor_data vendor_st = { .fifosize = 64, .lcrh_tx = ST_UART011_LCRH_TX, .lcrh_rx = ST_UART011_LCRH_RX, + .oversampling = true, }; static void pl011_stop_tx(struct uart_port *port) @@ -499,8 +503,13 @@ pl011_set_termios(struct uart_port *port, struct ktermios *termios, /* * Ask the core to calculate the divisor for us. */ - baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16); - quot = port->uartclk * 4 / baud; + baud = uart_get_baud_rate(port, termios, old, 0, + port->uartclk/(uap->oversampling ? 8 : 16)); + + if (baud > port->uartclk/16) + quot = DIV_ROUND_CLOSEST(port->uartclk * 8, baud); + else + quot = DIV_ROUND_CLOSEST(port->uartclk * 4, baud); switch (termios->c_cflag & CSIZE) { case CS5: @@ -579,6 +588,13 @@ pl011_set_termios(struct uart_port *port, struct ktermios *termios, uap->autorts = false; } + if (uap->oversampling) { + if (baud > port->uartclk/16) + old_cr |= ST_UART011_CR_OVSFACT; + else + old_cr &= ~ST_UART011_CR_OVSFACT; + } + /* Set baud rate */ writew(quot & 0x3f, port->membase + UART011_FBRD); writew(quot >> 6, port->membase + UART011_IBRD); @@ -744,6 +760,12 @@ pl011_console_get_options(struct uart_amba_port *uap, int *baud, fbrd = readw(uap->port.membase + UART011_FBRD); *baud = uap->port.uartclk * 4 / (64 * ibrd + fbrd); + + if (uap->oversampling) { + if (readw(uap->port.membase + UART011_CR) + & ST_UART011_CR_OVSFACT) + *baud *= 2; + } } } @@ -839,6 +861,7 @@ static int pl011_probe(struct amba_device *dev, struct amba_id *id) uap->ifls = vendor->ifls; uap->lcrh_rx = vendor->lcrh_rx; uap->lcrh_tx = vendor->lcrh_tx; + uap->oversampling = vendor->oversampling; uap->port.dev = &dev->dev; uap->port.mapbase = dev->res.start; uap->port.membase = base; diff --git a/include/linux/amba/serial.h b/include/linux/amba/serial.h index 93c96a66c518..e1b634b635f2 100644 --- a/include/linux/amba/serial.h +++ b/include/linux/amba/serial.h @@ -86,6 +86,7 @@ #define UART010_CR_TIE 0x0020 #define UART010_CR_RIE 0x0010 #define UART010_CR_MSIE 0x0008 +#define ST_UART011_CR_OVSFACT 0x0008 /* Oversampling factor */ #define UART01x_CR_IIRLP 0x0004 /* SIR low power mode */ #define UART01x_CR_SIREN 0x0002 /* SIR enable */ #define UART01x_CR_UARTEN 0x0001 /* UART enable */ |