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Commit 3f27b57c authored by Brian Niebuhr's avatar Brian Niebuhr Committed by Sekhar Nori
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spi: davinci: enable and power-up SPI only when required 



Enable SPI only when active transfers are in progress. Keep
it in local low power when not in use.

Signed-off-by: default avatarBrian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: default avatarMichael Williamson <michael.williamson@criticallink.com>
Signed-off-by: default avatarSekhar Nori <nsekhar@ti.com>
parent 3409e408

drivers/spi/davinci_spi.c

+6 −2
Original line number Diff line number Diff line
@@ -49,7 +49,6 @@ 
#define SPIFMT_WDELAY_SHIFT	24

#define SPIFMT_PRESCALE_SHIFT	8





/* SPIPC0 */

#define SPIPC0_DIFUN_MASK	BIT(11)		/* MISO */

#define SPIPC0_DOFUN_MASK	BIT(10)		/* MOSI */
@@ -67,6 +66,7 @@ 
/* SPIGCR1 */

#define SPIGCR1_CLKMOD_MASK	BIT(1)

#define SPIGCR1_MASTER_MASK     BIT(0)

#define SPIGCR1_POWERDOWN_MASK	BIT(8)

#define SPIGCR1_LOOPBACK_MASK	BIT(16)

#define SPIGCR1_SPIENA_MASK	BIT(24)
@@ -556,7 +556,7 @@ static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t) 


	data1_reg_val = ioread32(davinci_spi->base + SPIDAT1);



	/* Enable SPI */

	clear_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_POWERDOWN_MASK);

	set_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_SPIENA_MASK);



	INIT_COMPLETION(davinci_spi->done);
@@ -693,6 +693,9 @@ static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t) 
		clear_io_bits(davinci_spi->base + SPIINT, SPIINT_DMA_REQ_EN);

	}



	clear_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_SPIENA_MASK);

	set_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_POWERDOWN_MASK);



	/*

	 * Check for bit error, desync error,parity error,timeout error and

	 * receive overflow errors
@@ -937,6 +940,7 @@ static int davinci_spi_probe(struct platform_device *pdev) 
	/* master mode default */

	set_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_CLKMOD_MASK);

	set_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_MASTER_MASK);

	set_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_POWERDOWN_MASK);



	ret = spi_bitbang_start(&davinci_spi->bitbang);

	if (ret)