diff options
| author | Lorenzo Bianconi <lorenzo.bianconi@redhat.com> | 2018-07-28 11:19:14 +0300 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2018-08-01 16:50:28 +0300 |
| commit | 4b859db2c60692560afbfef1b030d0ddef57b7ee (patch) | |
| tree | 70a19c5a126a3eacdfda8f8112a13950cdca0a05 /drivers/spi | |
| parent | 304d34360b099020a12af2abb7e1ac506f4ba16d (diff) | |
| download | linux-4b859db2c60692560afbfef1b030d0ddef57b7ee.tar.xz | |
spi: spi-gpio: add SPI_3WIRE support
Add SPI_3WIRE support to spi-gpio controller introducing
set_line_direction function pointer in spi_bitbang data structure.
Spi-gpio controller has been tested using hts221 temp/rh iio sensor
running in 3wire mode and lsm6dsm running in 4wire mode
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/spi-bitbang.c | 16 | ||||
| -rw-r--r-- | drivers/spi/spi-gpio.c | 17 |
2 files changed, 32 insertions, 1 deletions
diff --git a/drivers/spi/spi-bitbang.c b/drivers/spi/spi-bitbang.c index 76f1b534bdd7..f29176000b8d 100644 --- a/drivers/spi/spi-bitbang.c +++ b/drivers/spi/spi-bitbang.c @@ -243,7 +243,23 @@ static int spi_bitbang_bufs(struct spi_device *spi, struct spi_transfer *t) { struct spi_bitbang_cs *cs = spi->controller_state; unsigned nsecs = cs->nsecs; + struct spi_bitbang *bitbang; + + bitbang = spi_master_get_devdata(spi->master); + if (bitbang->set_line_direction) { + int err; + err = bitbang->set_line_direction(spi, !!(t->tx_buf)); + if (err < 0) + return err; + } + + if (spi->mode & SPI_3WIRE) { + unsigned flags; + + flags = t->tx_buf ? SPI_MASTER_NO_RX : SPI_MASTER_NO_TX; + return cs->txrx_bufs(spi, cs->txrx_word, nsecs, t, flags); + } return cs->txrx_bufs(spi, cs->txrx_word, nsecs, t, 0); } diff --git a/drivers/spi/spi-gpio.c b/drivers/spi/spi-gpio.c index be68298cbd9c..0626e6e3ea0c 100644 --- a/drivers/spi/spi-gpio.c +++ b/drivers/spi/spi-gpio.c @@ -121,7 +121,10 @@ static inline int getmiso(const struct spi_device *spi) { struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi); - return !!gpiod_get_value_cansleep(spi_gpio->miso); + if (spi->mode & SPI_3WIRE) + return !!gpiod_get_value_cansleep(spi_gpio->mosi); + else + return !!gpiod_get_value_cansleep(spi_gpio->miso); } /* @@ -250,6 +253,16 @@ static int spi_gpio_setup(struct spi_device *spi) return status; } +static int spi_gpio_set_direction(struct spi_device *spi, bool output) +{ + struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi); + + if (output) + return gpiod_direction_output(spi_gpio->mosi, 1); + else + return gpiod_direction_input(spi_gpio->mosi); +} + static void spi_gpio_cleanup(struct spi_device *spi) { spi_bitbang_cleanup(spi); @@ -395,6 +408,7 @@ static int spi_gpio_probe(struct platform_device *pdev) return status; master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32); + master->mode_bits = SPI_3WIRE | SPI_CPHA | SPI_CPOL; master->flags = master_flags; master->bus_num = pdev->id; /* The master needs to think there is a chipselect even if not connected */ @@ -407,6 +421,7 @@ static int spi_gpio_probe(struct platform_device *pdev) spi_gpio->bitbang.master = master; spi_gpio->bitbang.chipselect = spi_gpio_chipselect; + spi_gpio->bitbang.set_line_direction = spi_gpio_set_direction; if ((master_flags & (SPI_MASTER_NO_TX | SPI_MASTER_NO_RX)) == 0) { spi_gpio->bitbang.txrx_word[SPI_MODE_0] = spi_gpio_txrx_word_mode0; |