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| author | Mark A. Greer <mgreer@animalcreek.com> | 2014-07-01 20:28:32 -0700 |
|---|---|---|
| committer | Mark Brown <broonie@linaro.org> | 2014-07-03 19:49:05 +0100 |
| commit | 97ca0d6cc118716840ea443e010cb3d5f2d25eaf (patch) | |
| tree | 63b55425bbb4f75caa656e812c9d9cd9714405d9 /drivers/spi/spi-omap2-mcspi.c | |
| parent | 7171511eaec5bf23fb06078f59784a3a0626b38f (diff) | |
| download | lwn-97ca0d6cc118716840ea443e010cb3d5f2d25eaf.tar.gz lwn-97ca0d6cc118716840ea443e010cb3d5f2d25eaf.zip | |
spi: omap2-mcspi: Configure hardware when slave driver changes mode
Commit id 2bd16e3e23d9df41592c6b257c59b6860a9cc3ea
(spi: omap2-mcspi: Do not configure the controller
on each transfer unless needed) does its job too
well so omap2_mcspi_setup_transfer() isn't called
even when an SPI slave driver changes 'spi->mode'.
The result is that the mode requested by the SPI
slave driver never takes effect.
Fix this by adding the 'mode' member to the
omap2_mcspi_cs structure which holds the mode
value that the hardware is configured for.
When the SPI slave driver changes 'spi->mode'
it will be different than the value of this new
member and the SPI master driver will know that
the hardware must be reconfigured (by calling
omap2_mcspi_setup_transfer()).
Fixes: 2bd16e3e23 (spi: omap2-mcspi: Do not configure the controller on each transfer unless needed)
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Cc: stable@vger.kernel.org
Diffstat (limited to 'drivers/spi/spi-omap2-mcspi.c')
| -rw-r--r-- | drivers/spi/spi-omap2-mcspi.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c index 4dc77df38864..68441fa448de 100644 --- a/drivers/spi/spi-omap2-mcspi.c +++ b/drivers/spi/spi-omap2-mcspi.c @@ -149,6 +149,7 @@ struct omap2_mcspi_cs { void __iomem *base; unsigned long phys; int word_len; + u16 mode; struct list_head node; /* Context save and restore shadow register */ u32 chconf0, chctrl0; @@ -926,6 +927,8 @@ static int omap2_mcspi_setup_transfer(struct spi_device *spi, mcspi_write_chconf0(spi, l); + cs->mode = spi->mode; + dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n", speed_hz, (spi->mode & SPI_CPHA) ? "trailing" : "leading", @@ -998,6 +1001,7 @@ static int omap2_mcspi_setup(struct spi_device *spi) return -ENOMEM; cs->base = mcspi->base + spi->chip_select * 0x14; cs->phys = mcspi->phys + spi->chip_select * 0x14; + cs->mode = 0; cs->chconf0 = 0; cs->chctrl0 = 0; spi->controller_state = cs; @@ -1079,6 +1083,16 @@ static void omap2_mcspi_work(struct omap2_mcspi *mcspi, struct spi_message *m) cs = spi->controller_state; cd = spi->controller_data; + /* + * The slave driver could have changed spi->mode in which case + * it will be different from cs->mode (the current hardware setup). + * If so, set par_override (even though its not a parity issue) so + * omap2_mcspi_setup_transfer will be called to configure the hardware + * with the correct mode on the first iteration of the loop below. + */ + if (spi->mode != cs->mode) + par_override = 1; + omap2_mcspi_set_enable(spi, 0); list_for_each_entry(t, &m->transfers, transfer_list) { if (t->tx_buf == NULL && t->rx_buf == NULL && t->len) { |