target/linux/brcm2708/patches-3.10/0046-spi-spi-bcm2708-respect-per-transfer-SPI-clock-speed.patch

   1 From 78948302252dcffa18716390f784ba03e4320c67 Mon Sep 17 00:00:00 2001
   2 From: Kamal Mostafa <kamal@whence.com>
   3 Date: Mon, 22 Oct 2012 15:52:44 -0700
   4 Subject: [PATCH 046/196] spi/spi-bcm2708: respect per-transfer SPI clock
   5  speed_hz value
   6
   7 The bcm2708 SPI driver's bcm2708_process_transfer() was ignoring the
   8 per-transfer speed_hz value even when it was provided (it always just
   9 used the spi device's max_speed_hz value).  Now, per-transfer speed_hz
  10 values are respected.
  11
  12 Also added debug print to bcm2708_setup_state() to help keep an eye on
  13 the configured SPI parameters.
  14
  15 Signed-off-by: Kamal Mostafa <kamal@whence.com>
  16 ---
  17  drivers/spi/spi-bcm2708.c | 7 ++++++-
  18  1 file changed, 6 insertions(+), 1 deletion(-)
  19
  20 diff --git a/drivers/spi/spi-bcm2708.c b/drivers/spi/spi-bcm2708.c
  21 index 8513704..b74aa32 100644
  22 --- a/drivers/spi/spi-bcm2708.c
  23 +++ b/drivers/spi/spi-bcm2708.c
  24 @@ -259,6 +259,10 @@ static int bcm2708_setup_state(struct spi_master *master,
  25         if (state) {
  26                 state->cs = cs;
  27                 state->cdiv = cdiv;
  28 +               dev_dbg(dev, "setup: want %d Hz; "
  29 +                       "bus_hz=%lu / cdiv=%u == %lu Hz; "
  30 +                       "mode %u: cs 0x%08X\n",
  31 +                       hz, bus_hz, cdiv, bus_hz/cdiv, mode, cs);
  32         }
  33
  34         return 0;
  35 @@ -277,7 +281,8 @@ static int bcm2708_process_transfer(struct bcm2708_spi *bs,
  36
  37         if (xfer->bits_per_word || xfer->speed_hz) {
  38                 ret = bcm2708_setup_state(spi->master, &spi->dev, &state,
  39 -                       spi->max_speed_hz, spi->chip_select, spi->mode,
  40 +                       xfer->speed_hz ? xfer->speed_hz : spi->max_speed_hz,
  41 +                       spi->chip_select, spi->mode,
  42                         spi->bits_per_word);
  43                 if (ret)
  44                         return ret;
  45 --
  46 1.9.1
  47