diff options
| author | Stefan Wahren <wahrenst@gmx.net> | 2025-08-07 12:07:42 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-08-28 16:34:42 +0200 |
| commit | 566f60ffbdbd6e0775ba26b0cde1c5a9b0d96ffe (patch) | |
| tree | 5127d7354303301994e6822b49216610e0f3410d | |
| parent | eb9a497b93306a0a4947c14d8141cb8c773da08d (diff) | |
spi: spi-fsl-lpspi: Clamp too high speed_hz
[ Upstream commit af357a6a3b7d685e7aa621c6fb1d4ed6c349ec9e ]
Currently the driver is not able to handle the case that a SPI device
specifies a higher spi-max-frequency than half of per-clk:
per-clk should be at least two times of transfer speed
Fix this by clamping to the max possible value and use the minimum SCK
period of 2 cycles.
Fixes: 77736a98b859 ("spi: lpspi: add the error info of transfer speed setting")
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Link: https://patch.msgid.link/20250807100742.9917-1-wahrenst@gmx.net
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/spi/spi-fsl-lpspi.c | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/drivers/spi/spi-fsl-lpspi.c b/drivers/spi/spi-fsl-lpspi.c index 5e3818445234..1a22d356a73d 100644 --- a/drivers/spi/spi-fsl-lpspi.c +++ b/drivers/spi/spi-fsl-lpspi.c @@ -331,13 +331,11 @@ static int fsl_lpspi_set_bitrate(struct fsl_lpspi_data *fsl_lpspi) } if (config.speed_hz > perclk_rate / 2) { - dev_err(fsl_lpspi->dev, - "per-clk should be at least two times of transfer speed"); - return -EINVAL; + div = 2; + } else { + div = DIV_ROUND_UP(perclk_rate, config.speed_hz); } - div = DIV_ROUND_UP(perclk_rate, config.speed_hz); - for (prescale = 0; prescale <= prescale_max; prescale++) { scldiv = div / (1 << prescale) - 2; if (scldiv >= 0 && scldiv < 256) { |