From: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
To: Mark Brown <broonie@kernel.org>,
linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] spi: dw: support 4-16 bits per word
Date: Wed, 8 Aug 2018 09:14:21 +0200 [thread overview]
Message-ID: <20180808071421.32707-1-simon.k.r.goldschmidt@gmail.com> (raw)
The spi-dw driver currently only supports 8 or 16 bits per word.
Since the hardware supports 4-16 bits per word, adapt the driver
to also support this.
Tested on socfpga cyclone5 with a 9-bit SPI display.
Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
---
drivers/spi/spi-dw.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c
index f693bfe95ab9..2ecbb6b19cea 100644
--- a/drivers/spi/spi-dw.c
+++ b/drivers/spi/spi-dw.c
@@ -307,14 +307,14 @@ static int dw_spi_transfer_one(struct spi_controller *master,
dws->current_freq = transfer->speed_hz;
spi_set_clk(dws, chip->clk_div);
}
- if (transfer->bits_per_word == 8) {
+ if ((transfer->bits_per_word < 4) || (transfer->bits_per_word > 16))
+ return -EINVAL;
+ if (transfer->bits_per_word <= 8) {
dws->n_bytes = 1;
dws->dma_width = 1;
- } else if (transfer->bits_per_word == 16) {
+ } else {
dws->n_bytes = 2;
dws->dma_width = 2;
- } else {
- return -EINVAL;
}
/* Default SPI mode is SCPOL = 0, SCPH = 0 */
cr0 = (transfer->bits_per_word - 1)
@@ -493,7 +493,7 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
}
master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP;
- master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
+ master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
master->bus_num = dws->bus_num;
master->num_chipselect = dws->num_cs;
master->setup = dw_spi_setup;
--
2.17.1
next reply other threads:[~2018-08-08 7:14 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-08 7:14 Simon Goldschmidt [this message]
2018-08-08 9:45 ` [PATCH] spi: dw: support 4-16 bits per word Andy Shevchenko
2018-08-08 11:58 ` Simon Goldschmidt
2018-08-08 12:26 ` Andy Shevchenko
2018-08-17 7:01 ` [PATCH v2] " Simon Goldschmidt
2018-08-17 11:17 ` Andy Shevchenko
2018-08-17 16:32 ` Trent Piepho
2018-08-18 8:37 ` Simon Goldschmidt
2018-09-04 19:49 ` [PATCH v3] " Simon Goldschmidt
2018-09-06 11:09 ` Mark Brown
2018-09-06 11:23 ` Simon Goldschmidt
2018-09-06 13:23 ` Mark Brown
2018-09-06 13:37 ` Simon Goldschmidt
2018-09-06 11:10 ` Applied "spi: dw: support 4-16 bits per word" to the spi tree Mark Brown
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