spi: orion: On a38x, implement "50MHZ SPI AC timing" Erratum No. FE-9144572 (38d6211e) · Commits · 戴 / test

drivers/spi/spi-orion.c

+53 −1

Original line number	Diff line number	Diff line
		@@ -41,6 +41,11 @@
		#define ORION_SPI_DATA_OUT_REG 0x08
		#define ORION_SPI_DATA_IN_REG 0x0c
		#define ORION_SPI_INT_CAUSE_REG 0x10
		#define ORION_SPI_TIMING_PARAMS_REG 0x18

		#define ORION_SPI_TMISO_SAMPLE_MASK (0x3 << 6)
		#define ORION_SPI_TMISO_SAMPLE_1 (1 << 6)
		#define ORION_SPI_TMISO_SAMPLE_2 (2 << 6)

		#define ORION_SPI_MODE_CPOL (1 << 11)
		#define ORION_SPI_MODE_CPHA (1 << 12)
		@@ -70,6 +75,7 @@ struct orion_spi_dev {
		unsigned int min_divisor;
		unsigned int max_divisor;
		u32 prescale_mask;
		bool is_errata_50mhz_ac;
		};

		struct orion_spi {
		@@ -195,6 +201,41 @@ orion_spi_mode_set(struct spi_device *spi)
		writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
		}

		static void
		orion_spi_50mhz_ac_timing_erratum(struct spi_device *spi, unsigned int speed)
		{
		u32 reg;
		struct orion_spi *orion_spi;

		orion_spi = spi_master_get_devdata(spi->master);

		/*
		* Erratum description: (Erratum NO. FE-9144572) The device
		* SPI interface supports frequencies of up to 50 MHz.
		* However, due to this erratum, when the device core clock is
		* 250 MHz and the SPI interfaces is configured for 50MHz SPI
		* clock and CPOL=CPHA=1 there might occur data corruption on
		* reads from the SPI device.
		* Erratum Workaround:
		* Work in one of the following configurations:
		* 1. Set CPOL=CPHA=0 in "SPI Interface Configuration
		* Register".
		* 2. Set TMISO_SAMPLE value to 0x2 in "SPI Timing Parameters 1
		* Register" before setting the interface.
		*/
		reg = readl(spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG));
		reg &= ~ORION_SPI_TMISO_SAMPLE_MASK;

		if (clk_get_rate(orion_spi->clk) == 250000000 &&
		speed == 50000000 && spi->mode & SPI_CPOL &&
		spi->mode & SPI_CPHA)
		reg \|= ORION_SPI_TMISO_SAMPLE_2;
		else
		reg \|= ORION_SPI_TMISO_SAMPLE_1; /* This is the default value */

		writel(reg, spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG));
		}

		/*
		* called only when no transfer is active on the bus
		*/
		@@ -216,6 +257,9 @@ orion_spi_setup_transfer(struct spi_device spi, struct spi_transfer t)

		orion_spi_mode_set(spi);

		if (orion_spi->devdata->is_errata_50mhz_ac)
		orion_spi_50mhz_ac_timing_erratum(spi, speed);

		rc = orion_spi_baudrate_set(spi, speed);
		if (rc)
		return rc;
		@@ -413,6 +457,14 @@ static const struct orion_spi_dev armada_375_spi_dev_data = {
		.prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
		};

		static const struct orion_spi_dev armada_380_spi_dev_data = {
		.typ = ARMADA_SPI,
		.max_hz = 50000000,
		.max_divisor = 1920,
		.prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
		.is_errata_50mhz_ac = true,
		};

		static const struct of_device_id orion_spi_of_match_table[] = {
		{
		.compatible = "marvell,orion-spi",
		@@ -428,7 +480,7 @@ static const struct of_device_id orion_spi_of_match_table[] = {
		},
		{
		.compatible = "marvell,armada-380-spi",
		.data = &armada_xp_spi_dev_data,
		.data = &armada_380_spi_dev_data,
		},
		{
		.compatible = "marvell,armada-390-spi",

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