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

Commit 6557b1f6 authored by Laurent Pinchart's avatar Laurent Pinchart Committed by Simon Horman
Browse files

serial: sh-sci: Simplify baud rate calculation algorithms 



Rewrite the baud rate register value calculations in easier to read
forms. The computed value isn't modified.

Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarSimon Horman <horms+renesas@verge.net.au>
parent 6db201da

drivers/tty/serial/sh-sci.c

+4 −4
Original line number Diff line number Diff line
@@ -1818,13 +1818,13 @@ static unsigned int sci_scbrr_calc(unsigned int algo_id, unsigned int bps, 
{

	switch (algo_id) {

	case SCBRR_ALGO_1:

		return ((freq + 16 * bps) / (16 * bps) - 1);

		return freq / (16 * bps);

	case SCBRR_ALGO_2:

		return ((freq + 16 * bps) / (32 * bps) - 1);

		return DIV_ROUND_CLOSEST(freq, 32 * bps) - 1;

	case SCBRR_ALGO_3:

		return (((freq * 2) + 16 * bps) / (16 * bps) - 1);

		return freq / (8 * bps);

	case SCBRR_ALGO_4:

		return (((freq * 2) + 16 * bps) / (32 * bps) - 1);

		return DIV_ROUND_CLOSEST(freq, 16 * bps) - 1;

	}



	/* Warn, but use a safe default */

include/linux/serial_sci.h

+4 −4
Original line number Diff line number Diff line
@@ -11,10 +11,10 @@ 
#define SCIx_NOT_SUPPORTED	(-1)



enum {

	SCBRR_ALGO_1,		/* ((clk + 16 * bps) / (16 * bps) - 1) */

	SCBRR_ALGO_2,		/* ((clk + 16 * bps) / (32 * bps) - 1) */

	SCBRR_ALGO_3,		/* (((clk * 2) + 16 * bps) / (16 * bps) - 1) */

	SCBRR_ALGO_4,		/* (((clk * 2) + 16 * bps) / (32 * bps) - 1) */

	SCBRR_ALGO_1,		/* clk / (16 * bps) */

	SCBRR_ALGO_2,		/* DIV_ROUND_CLOSEST(clk, 32 * bps) - 1 */

	SCBRR_ALGO_3,		/* clk / (8 * bps) */

	SCBRR_ALGO_4,		/* DIV_ROUND_CLOSEST(clk, 16 * bps) - 1 */

	SCBRR_ALGO_6,		/* HSCIF variable sample rate algorithm */

};