From 98fbd71d7a4492e23377b8753cfd77add26c63ec Mon Sep 17 00:00:00 2001 From: Chin Liang See Date: Sat, 17 Oct 2015 08:31:55 -0500 Subject: [PATCH] spi: cadence_qspi: Ensure spi_calibration is run when sclk change Ensuring spi_calibration is run when there is a change of sclk frequency. This will ensure the qspi flash access works for high sclk frequency Signed-off-by: Chin Liang See Cc: Dinh Nguyen Cc: Dinh Nguyen Cc: Marek Vasut Cc: Stefan Roese Cc: Vikas Manocha Cc: Jagannadh Teki Cc: Pavel Machek Acked-by: Marek Vasut Reviewed-by: Jagan Teki --- drivers/spi/cadence_qspi.c | 22 +++++++++++++--------- drivers/spi/cadence_qspi.h | 1 + 2 files changed, 14 insertions(+), 9 deletions(-) diff --git a/drivers/spi/cadence_qspi.c b/drivers/spi/cadence_qspi.c index 34a0f46..c5a4276 100644 --- a/drivers/spi/cadence_qspi.c +++ b/drivers/spi/cadence_qspi.c @@ -37,9 +37,8 @@ static int cadence_spi_write_speed(struct udevice *bus, uint hz) } /* Calibration sequence to determine the read data capture delay register */ -static int spi_calibration(struct udevice *bus) +static int spi_calibration(struct udevice *bus, uint hz) { - struct cadence_spi_platdata *plat = bus->platdata; struct cadence_spi_priv *priv = dev_get_priv(bus); void *base = priv->regbase; u8 opcode_rdid = 0x9F; @@ -64,7 +63,7 @@ static int spi_calibration(struct udevice *bus) } /* use back the intended clock and find low range */ - cadence_spi_write_speed(bus, plat->max_hz); + cadence_spi_write_speed(bus, hz); for (i = 0; i < CQSPI_READ_CAPTURE_MAX_DELAY; i++) { /* Disable QSPI */ cadence_qspi_apb_controller_disable(base); @@ -111,7 +110,7 @@ static int spi_calibration(struct udevice *bus) (range_hi + range_lo) / 2, range_lo, range_hi); /* just to ensure we do once only when speed or chip select change */ - priv->qspi_calibrated_hz = plat->max_hz; + priv->qspi_calibrated_hz = hz; priv->qspi_calibrated_cs = spi_chip_select(bus); return 0; @@ -126,14 +125,19 @@ static int cadence_spi_set_speed(struct udevice *bus, uint hz) /* Disable QSPI */ cadence_qspi_apb_controller_disable(priv->regbase); - cadence_spi_write_speed(bus, hz); - - /* Calibration required for different SCLK speed or chip select */ - if (priv->qspi_calibrated_hz != plat->max_hz || + /* + * Calibration required for different current SCLK speed, requested + * SCLK speed or chip select + */ + if (priv->previous_hz != hz || + priv->qspi_calibrated_hz != hz || priv->qspi_calibrated_cs != spi_chip_select(bus)) { - err = spi_calibration(bus); + err = spi_calibration(bus, hz); if (err) return err; + + /* prevent calibration run when same as previous request */ + priv->previous_hz = hz; } /* Enable QSPI */ diff --git a/drivers/spi/cadence_qspi.h b/drivers/spi/cadence_qspi.h index 98e57aa..2912e36 100644 --- a/drivers/spi/cadence_qspi.h +++ b/drivers/spi/cadence_qspi.h @@ -38,6 +38,7 @@ struct cadence_spi_priv { int qspi_is_init; unsigned int qspi_calibrated_hz; unsigned int qspi_calibrated_cs; + unsigned int previous_hz; }; /* Functions call declaration */ -- 2.7.4