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author | Brian Niebuhr <bniebuhr@efjohnson.com> | 2010-08-13 10:11:03 +0530 |
---|---|---|
committer | Sekhar Nori <nsekhar@ti.com> | 2010-11-18 18:38:24 +0530 |
commit | 7978b8c385a86f0b5b9304e81a1dfb5dcaf21528 (patch) | |
tree | ff13c4dd8d8cd570d57d50f072e8cdab3c97ea5f /drivers/spi/davinci_spi.c | |
parent | 843a713bc53d04f8fac46ddd8693a2cc0422ca5e (diff) | |
download | op-kernel-dev-7978b8c385a86f0b5b9304e81a1dfb5dcaf21528.zip op-kernel-dev-7978b8c385a86f0b5b9304e81a1dfb5dcaf21528.tar.gz |
spi: davinci: enable both activation and deactivation of chip-selects
Let davinci_spi_chipselect() perform both activation and
deactivation of chip selects. This lets spi_bitbang fully
control chip select activation, as intended by the SPI API.
With this change, the chip select activation code need not
be duplicated in davinci_spi_bufs_{pio|dma}().
Also, keeping chip select active control is removed as a
platform data and simply controlled using information from
spi_bitbang on whether chip slect should be activated or
de-activated.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Diffstat (limited to 'drivers/spi/davinci_spi.c')
-rw-r--r-- | drivers/spi/davinci_spi.c | 53 |
1 files changed, 18 insertions, 35 deletions
diff --git a/drivers/spi/davinci_spi.c b/drivers/spi/davinci_spi.c index d6b6a49..105c686 100644 --- a/drivers/spi/davinci_spi.c +++ b/drivers/spi/davinci_spi.c @@ -66,7 +66,7 @@ #define SPI_INTLVL_0 0x00000000u /* SPIDAT1 */ -#define SPIDAT1_CSHOLD_SHIFT 28 +#define SPIDAT1_CSHOLD_MASK BIT(28) #define SPIDAT1_CSNR_SHIFT 16 #define SPIGCR1_CLKMOD_MASK BIT(1) #define SPIGCR1_MASTER_MASK BIT(0) @@ -235,7 +235,8 @@ static void davinci_spi_chipselect(struct spi_device *spi, int value) { struct davinci_spi *davinci_spi; struct davinci_spi_platform_data *pdata; - u32 data1_reg_val = 0; + u32 data1_reg_val; + u8 chip_sel = spi->chip_select; davinci_spi = spi_master_get_devdata(spi->master); pdata = davinci_spi->pdata; @@ -244,14 +245,17 @@ static void davinci_spi_chipselect(struct spi_device *spi, int value) * Board specific chip select logic decides the polarity and cs * line for the controller */ - if (value == BITBANG_CS_INACTIVE) { - data1_reg_val |= CS_DEFAULT << SPIDAT1_CSNR_SHIFT; - iowrite32(data1_reg_val, davinci_spi->base + SPIDAT1); - - while ((ioread32(davinci_spi->base + SPIBUF) - & SPIBUF_RXEMPTY_MASK) == 0) - cpu_relax(); + data1_reg_val = CS_DEFAULT << SPIDAT1_CSNR_SHIFT; + if (value == BITBANG_CS_ACTIVE) { + data1_reg_val |= SPIDAT1_CSHOLD_MASK; + data1_reg_val &= ~((0x1 << chip_sel) << SPIDAT1_CSNR_SHIFT); } + + iowrite32(data1_reg_val, davinci_spi->base + SPIDAT1); + while ((ioread32(davinci_spi->base + SPIBUF) + & SPIBUF_RXEMPTY_MASK) == 0) + cpu_relax(); + } /** @@ -632,7 +636,7 @@ static int davinci_spi_bufs_pio(struct spi_device *spi, struct spi_transfer *t) { struct davinci_spi *davinci_spi; int int_status, count, ret; - u8 conv, tmp; + u8 conv; u32 tx_data, data1_reg_val; u32 buf_val, flg_val; struct davinci_spi_platform_data *pdata; @@ -647,6 +651,8 @@ static int davinci_spi_bufs_pio(struct spi_device *spi, struct spi_transfer *t) conv = davinci_spi->slave[spi->chip_select].bytes_per_word; davinci_spi->count = t->len / conv; + data1_reg_val = ioread32(davinci_spi->base + SPIDAT1); + INIT_COMPLETION(davinci_spi->done); ret = davinci_spi_bufs_prep(spi, davinci_spi); @@ -661,16 +667,6 @@ static int davinci_spi_bufs_pio(struct spi_device *spi, struct spi_transfer *t) davinci_spi->base + SPIDELAY); count = davinci_spi->count; - data1_reg_val = pdata->cs_hold << SPIDAT1_CSHOLD_SHIFT; - tmp = ~(0x1 << spi->chip_select); - - clear_io_bits(davinci_spi->base + SPIDEF, ~tmp); - - data1_reg_val |= tmp << SPIDAT1_CSNR_SHIFT; - - while ((ioread32(davinci_spi->base + SPIBUF) - & SPIBUF_RXEMPTY_MASK) == 0) - cpu_relax(); /* Determine the command to execute READ or WRITE */ if (t->tx_buf) { @@ -770,7 +766,6 @@ static int davinci_spi_bufs_dma(struct spi_device *spi, struct spi_transfer *t) int int_status = 0; int count, temp_count; u8 conv = 1; - u8 tmp; u32 data1_reg_val; struct davinci_spi_dma *davinci_spi_dma; int word_len, data_type, ret; @@ -794,6 +789,8 @@ static int davinci_spi_bufs_dma(struct spi_device *spi, struct spi_transfer *t) conv = davinci_spi->slave[spi->chip_select].bytes_per_word; davinci_spi->count = t->len / conv; + data1_reg_val = ioread32(davinci_spi->base + SPIDAT1); + INIT_COMPLETION(davinci_spi->done); init_completion(&davinci_spi_dma->dma_rx_completion); @@ -820,28 +817,14 @@ static int davinci_spi_bufs_dma(struct spi_device *spi, struct spi_transfer *t) davinci_spi->base + SPIDELAY); count = davinci_spi->count; /* the number of elements */ - data1_reg_val = pdata->cs_hold << SPIDAT1_CSHOLD_SHIFT; - - /* CS default = 0xFF */ - tmp = ~(0x1 << spi->chip_select); - - clear_io_bits(davinci_spi->base + SPIDEF, ~tmp); - - data1_reg_val |= tmp << SPIDAT1_CSNR_SHIFT; /* disable all interrupts for dma transfers */ clear_io_bits(davinci_spi->base + SPIINT, SPIINT_MASKALL); /* Disable SPI to write configuration bits in SPIDAT */ clear_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_SPIENA_MASK); - iowrite32(data1_reg_val, davinci_spi->base + SPIDAT1); /* Enable SPI */ set_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_SPIENA_MASK); - while ((ioread32(davinci_spi->base + SPIBUF) - & SPIBUF_RXEMPTY_MASK) == 0) - cpu_relax(); - - if (t->tx_buf) { t->tx_dma = dma_map_single(&spi->dev, (void *)t->tx_buf, count, DMA_TO_DEVICE); |