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| author | Geert Uytterhoeven <geert+renesas@glider.be> | 2020-03-09 18:15:37 +0100 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2020-03-10 14:30:56 +0000 |
| commit | f3a14a3a4d9a54c665e979b1dedbbab1f7503a43 (patch) | |
| tree | 051fa2c7ca5cf23b0ec6feff17ca0f152a5c78b5 /drivers/spi/spi-rspi.c | |
| parent | c6486eadb4feae730b68dda95fe2cc8dbe210fae (diff) | |
| download | lwn-f3a14a3a4d9a54c665e979b1dedbbab1f7503a43.tar.gz lwn-f3a14a3a4d9a54c665e979b1dedbbab1f7503a43.zip | |
spi: rspi: Add support for active-high chip selects
All RSPI variants support setting the polarity of the SSL signal.
Advertize support for active-high chip selects, and configure polarity
according to the state of the flag.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200309171537.21551-1-geert+renesas@glider.be
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi/spi-rspi.c')
| -rw-r--r-- | drivers/spi/spi-rspi.c | 36 |
1 files changed, 32 insertions, 4 deletions
diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c index aef05f2ac749..06192c9ea813 100644 --- a/drivers/spi/spi-rspi.c +++ b/drivers/spi/spi-rspi.c @@ -24,6 +24,7 @@ #include <linux/sh_dma.h> #include <linux/spi/spi.h> #include <linux/spi/rspi.h> +#include <linux/spinlock.h> #define RSPI_SPCR 0x00 /* Control Register */ #define RSPI_SSLP 0x01 /* Slave Select Polarity Register */ @@ -79,8 +80,7 @@ #define SPCR_BSWAP 0x01 /* Byte Swap of read-data for DMAC */ /* SSLP - Slave Select Polarity Register */ -#define SSLP_SSL1P 0x02 /* SSL1 Signal Polarity Setting */ -#define SSLP_SSL0P 0x01 /* SSL0 Signal Polarity Setting */ +#define SSLP_SSLP(i) BIT(i) /* SSLi Signal Polarity Setting */ /* SPPCR - Pin Control Register */ #define SPPCR_MOIFE 0x20 /* MOSI Idle Value Fixing Enable */ @@ -181,7 +181,9 @@ struct rspi_data { void __iomem *addr; u32 max_speed_hz; struct spi_controller *ctlr; + struct platform_device *pdev; wait_queue_head_t wait; + spinlock_t lock; /* Protects RMW-access to RSPI_SSLP */ struct clk *clk; u16 spcmd; u8 spsr; @@ -919,6 +921,29 @@ static int qspi_setup_sequencer(struct rspi_data *rspi, return 0; } +static int rspi_setup(struct spi_device *spi) +{ + struct rspi_data *rspi = spi_controller_get_devdata(spi->controller); + u8 sslp; + + if (spi->cs_gpiod) + return 0; + + pm_runtime_get_sync(&rspi->pdev->dev); + spin_lock_irq(&rspi->lock); + + sslp = rspi_read8(rspi, RSPI_SSLP); + if (spi->mode & SPI_CS_HIGH) + sslp |= SSLP_SSLP(spi->chip_select); + else + sslp &= ~SSLP_SSLP(spi->chip_select); + rspi_write8(rspi, sslp, RSPI_SSLP); + + spin_unlock_irq(&rspi->lock); + pm_runtime_put(&rspi->pdev->dev); + return 0; +} + static int rspi_prepare_message(struct spi_controller *ctlr, struct spi_message *msg) { @@ -1248,17 +1273,20 @@ static int rspi_probe(struct platform_device *pdev) goto error1; } + rspi->pdev = pdev; pm_runtime_enable(&pdev->dev); init_waitqueue_head(&rspi->wait); + spin_lock_init(&rspi->lock); ctlr->bus_num = pdev->id; + ctlr->setup = rspi_setup; ctlr->auto_runtime_pm = true; ctlr->transfer_one = ops->transfer_one; ctlr->prepare_message = rspi_prepare_message; ctlr->unprepare_message = rspi_unprepare_message; - ctlr->mode_bits = SPI_CPHA | SPI_CPOL | SPI_LSB_FIRST | SPI_LOOP | - ops->extra_mode_bits; + ctlr->mode_bits = SPI_CPHA | SPI_CPOL | SPI_CS_HIGH | SPI_LSB_FIRST | + SPI_LOOP | ops->extra_mode_bits; ctlr->flags = ops->flags; ctlr->dev.of_node = pdev->dev.of_node; ctlr->use_gpio_descriptors = true; |