diff options
Diffstat (limited to 'drivers/spi/spi-orion.c')
| -rw-r--r-- | drivers/spi/spi-orion.c | 54 |
1 files changed, 53 insertions, 1 deletions
diff --git a/drivers/spi/spi-orion.c b/drivers/spi/spi-orion.c index 8cad107a5..a87cfd4ba 100644 --- a/drivers/spi/spi-orion.c +++ b/drivers/spi/spi-orion.c @@ -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", |