diff options
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/sh-sci.c | 37 |
1 files changed, 30 insertions, 7 deletions
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index d5239d5ff98b..e4bf0e435af6 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -65,6 +65,7 @@ struct sci_port { struct plat_sci_port *cfg; int overrun_bit; unsigned int error_mask; + unsigned int sampling_rate; /* Break timer */ @@ -1750,10 +1751,13 @@ static void sci_shutdown(struct uart_port *port) sci_free_irq(s); } -static unsigned int sci_scbrr_calc(unsigned int algo_id, unsigned int bps, +static unsigned int sci_scbrr_calc(struct sci_port *s, unsigned int bps, unsigned long freq) { - switch (algo_id) { + if (s->sampling_rate) + return DIV_ROUND_CLOSEST(freq, s->sampling_rate * bps) - 1; + + switch (s->cfg->scbrr_algo_id) { case SCBRR_ALGO_1: return freq / (16 * bps); case SCBRR_ALGO_2: @@ -1843,12 +1847,11 @@ 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->scbrr_algo_id == SCBRR_ALGO_6) { + if (s->cfg->type == PORT_HSCIF) { sci_baud_calc_hscif(baud, port->uartclk, &t, &srr, &cks); } else { - t = sci_scbrr_calc(s->cfg->scbrr_algo_id, baud, - port->uartclk); + t = sci_scbrr_calc(s, baud, port->uartclk); for (cks = 0; t >= 256 && cks <= 3; cks++) t >>= 2; } @@ -2092,6 +2095,7 @@ static int sci_init_single(struct platform_device *dev, { struct uart_port *port = &sci_port->port; const struct resource *res; + unsigned int sampling_rate; unsigned int i; int ret; @@ -2143,28 +2147,47 @@ static int sci_init_single(struct platform_device *dev, case PORT_SCIFB: port->fifosize = 256; sci_port->overrun_bit = 9; + sampling_rate = 16; break; case PORT_HSCIF: port->fifosize = 128; + sampling_rate = 0; sci_port->overrun_bit = 0; break; case PORT_SCIFA: port->fifosize = 64; sci_port->overrun_bit = 9; + sampling_rate = 16; break; case PORT_SCIF: port->fifosize = 16; - if (p->regtype == SCIx_SH7705_SCIF_REGTYPE) + if (p->regtype == SCIx_SH7705_SCIF_REGTYPE) { sci_port->overrun_bit = 9; - else + sampling_rate = 16; + } else { sci_port->overrun_bit = 0; + sampling_rate = 32; + } break; default: port->fifosize = 1; sci_port->overrun_bit = 5; + sampling_rate = 32; break; } + /* Set the sampling rate if the baud rate calculation algorithm isn't + * specified. + */ + if (p->scbrr_algo_id == SCBRR_ALGO_NONE) { + /* SCIFA on sh7723 and sh7724 need a custom sampling rate that + * doesn't match the SoC datasheet, this should be investigated. + * Let platform data override the sampling rate for now. + */ + sci_port->sampling_rate = p->sampling_rate ? p->sampling_rate + : sampling_rate; + } + if (!early) { sci_port->iclk = clk_get(&dev->dev, "sci_ick"); if (IS_ERR(sci_port->iclk)) { |