diff options
Diffstat (limited to 'drivers/tty/serial/sh-sci.c')
| -rw-r--r-- | drivers/tty/serial/sh-sci.c | 21 |
1 files changed, 8 insertions, 13 deletions
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index c490c51d6032..306497ee5c32 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1867,12 +1867,13 @@ static unsigned int sci_scbrr_calc(struct sci_port *s, unsigned int bps, } /* calculate sample rate, BRR, and clock select for HSCIF */ -static void sci_baud_calc_hscif(unsigned int bps, unsigned long freq, int *brr, +static void sci_baud_calc_hscif(struct sci_port *s, unsigned int bps, + unsigned long freq, int *brr, unsigned int *srr, unsigned int *cks) { unsigned int sr, br, prediv, scrate, c; int err, recv_margin; - int min_err = 1000; /* 100% */ + int min_err = INT_MAX; int recv_max_margin = 0; /* Find the combination of sample rate and clock select with the @@ -1886,7 +1887,7 @@ static void sci_baud_calc_hscif(unsigned int bps, unsigned long freq, int *brr, * We need to calculate: * * br = freq / (prediv * bps) clamped to [1..256] - * err = (freq / (br * prediv * bps / 1000)) - 1000 + * err = freq / (br * prediv) - bps * * Watch out for overflow when calculating the desired * sampling clock rate! @@ -1897,8 +1898,7 @@ static void sci_baud_calc_hscif(unsigned int bps, unsigned long freq, int *brr, scrate = prediv * bps; br = DIV_ROUND_CLOSEST(freq, scrate); br = clamp(br, 1U, 256U); - err = DIV_ROUND_CLOSEST(freq, (br * scrate) / 1000) - - 1000; + err = DIV_ROUND_CLOSEST(freq, br * prediv) - bps; /* Calc recv margin * M: Receive margin (%) * N: Ratio of bit rate to clock (N = sampling rate) @@ -1928,13 +1928,8 @@ static void sci_baud_calc_hscif(unsigned int bps, unsigned long freq, int *brr, } } - if (min_err == 1000) { - WARN_ON(1); - /* use defaults */ - *brr = 255; - *srr = 15; - *cks = 0; - } + dev_dbg(s->port.dev, "BRR: %u%+d bps using N %u SR %u cks %u\n", bps, + min_err, *brr, *srr + 1, *cks); } static void sci_reset(struct uart_port *port) @@ -1984,7 +1979,7 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios, baud = uart_get_baud_rate(port, termios, old, 0, max_baud); if (likely(baud && port->uartclk)) { if (s->cfg->type == PORT_HSCIF) { - sci_baud_calc_hscif(baud, port->uartclk, &t, &srr, + sci_baud_calc_hscif(s, baud, port->uartclk, &t, &srr, &cks); } else { t = sci_scbrr_calc(s, baud, port->uartclk); |