| From 09419333d40b298b7d6eeae4f53de1e00900e756 Mon Sep 17 00:00:00 2001 |
| From: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> |
| Date: Fri, 6 Dec 2013 10:59:12 +0100 |
| Subject: 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: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> |
| Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| Signed-off-by: Simon Horman <horms+renesas@verge.net.au> |
| (cherry picked from commit 6557b1f69ea0961efde7ab33bfe0cb7e3bfed54e) |
| (Queued by Simon Horman for v3.14 but not yet in Linus's tree) |
| Signed-off-by: Simon Horman <horms+renesas@verge.net.au> |
| --- |
| drivers/tty/serial/sh-sci.c | 8 ++++---- |
| include/linux/serial_sci.h | 8 ++++---- |
| 2 files changed, 8 insertions(+), 8 deletions(-) |
| |
| diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c |
| index 80a91038c821..94e878cacd50 100644 |
| --- a/drivers/tty/serial/sh-sci.c |
| +++ b/drivers/tty/serial/sh-sci.c |
| @@ -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 */ |
| diff --git a/include/linux/serial_sci.h b/include/linux/serial_sci.h |
| index 803068d764fb..eb787d40df02 100644 |
| --- a/include/linux/serial_sci.h |
| +++ b/include/linux/serial_sci.h |
| @@ -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 */ |
| }; |
| |
| -- |
| 1.8.5.rc3 |
| |
