Skip to content

Commit

Permalink
spi: sun4i: allow transfers to set transmission speed
Browse files Browse the repository at this point in the history
Allow transfers to set the transmission speed rather than using the
device max_speed_hz value. The SPI core makes sure that the speed_hz
value is always set on the transfer.

Signed-off-by: Marcus Weseloh <mweseloh42@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
  • Loading branch information
Marcus Weseloh authored and Mark Brown committed Nov 18, 2015
1 parent 8005c49 commit 47284e3
Show file tree
Hide file tree
Showing 2 changed files with 8 additions and 8 deletions.
8 changes: 4 additions & 4 deletions drivers/spi/spi-sun4i.c
Original file line number Diff line number Diff line change
Expand Up @@ -229,8 +229,8 @@ static int sun4i_spi_transfer_one(struct spi_master *master,

/* Ensure that we have a parent clock fast enough */
mclk_rate = clk_get_rate(sspi->mclk);
if (mclk_rate < (2 * spi->max_speed_hz)) {
clk_set_rate(sspi->mclk, 2 * spi->max_speed_hz);
if (mclk_rate < (2 * tfr->speed_hz)) {
clk_set_rate(sspi->mclk, 2 * tfr->speed_hz);
mclk_rate = clk_get_rate(sspi->mclk);
}

Expand All @@ -248,14 +248,14 @@ static int sun4i_spi_transfer_one(struct spi_master *master,
* First try CDR2, and if we can't reach the expected
* frequency, fall back to CDR1.
*/
div = mclk_rate / (2 * spi->max_speed_hz);
div = mclk_rate / (2 * tfr->speed_hz);
if (div <= (SUN4I_CLK_CTL_CDR2_MASK + 1)) {
if (div > 0)
div--;

reg = SUN4I_CLK_CTL_CDR2(div) | SUN4I_CLK_CTL_DRS;
} else {
div = ilog2(mclk_rate) - ilog2(spi->max_speed_hz);
div = ilog2(mclk_rate) - ilog2(tfr->speed_hz);
reg = SUN4I_CLK_CTL_CDR1(div);
}

Expand Down
8 changes: 4 additions & 4 deletions drivers/spi/spi-sun6i.c
Original file line number Diff line number Diff line change
Expand Up @@ -217,8 +217,8 @@ static int sun6i_spi_transfer_one(struct spi_master *master,

/* Ensure that we have a parent clock fast enough */
mclk_rate = clk_get_rate(sspi->mclk);
if (mclk_rate < (2 * spi->max_speed_hz)) {
clk_set_rate(sspi->mclk, 2 * spi->max_speed_hz);
if (mclk_rate < (2 * tfr->speed_hz)) {
clk_set_rate(sspi->mclk, 2 * tfr->speed_hz);
mclk_rate = clk_get_rate(sspi->mclk);
}

Expand All @@ -236,14 +236,14 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
* First try CDR2, and if we can't reach the expected
* frequency, fall back to CDR1.
*/
div = mclk_rate / (2 * spi->max_speed_hz);
div = mclk_rate / (2 * tfr->speed_hz);
if (div <= (SUN6I_CLK_CTL_CDR2_MASK + 1)) {
if (div > 0)
div--;

reg = SUN6I_CLK_CTL_CDR2(div) | SUN6I_CLK_CTL_DRS;
} else {
div = ilog2(mclk_rate) - ilog2(spi->max_speed_hz);
div = ilog2(mclk_rate) - ilog2(tfr->speed_hz);
reg = SUN6I_CLK_CTL_CDR1(div);
}

Expand Down

0 comments on commit 47284e3

Please sign in to comment.