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spi: cadence-quadspi: Disable the SPI before reconfiguring

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Observed random DMA timeout failures while doing back to back
transfers which involves switching the modes from DMA to NON-DMA.
This issue is observed while testing the OSPI+UBIFS file system test case
where rootfs is mounted from OSPI UBIFS partition.
To avoid this issue, disable the SPI before changing the configuration
from external DMA to NON-DMA and vice versa and reenable it after changing
the configuration.
As per the Cadence Octal SPI design specification, it is recommended to
disable the Octal-SPI enable bit before reconfiguring.

Signed-off-by: Sai Krishna Potthuri <sai.krishna.potthuri@amd.com>
Link: https://lore.kernel.org/r/20230320095931.2651714-3-sai.krishna.potthuri@amd.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Sai Krishna Potthuri 2023-03-20 15:29:31 +05:30 committed by Mark Brown
parent 22c8ce0aa2
commit c0b53f4e54
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
1 changed files with 23 additions and 15 deletions
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38
drivers/spi/spi-cadence-quadspi.c
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@ -791,6 +791,21 @@ failrd:
return ret;
}
static void cqspi_controller_enable(struct cqspi_st *cqspi, bool enable)
{
void __iomem *reg_base = cqspi->iobase;
unsigned int reg;
reg = readl(reg_base + CQSPI_REG_CONFIG);
if (enable)
reg |= CQSPI_REG_CONFIG_ENABLE_MASK;
else
reg &= ~CQSPI_REG_CONFIG_ENABLE_MASK;
writel(reg, reg_base + CQSPI_REG_CONFIG);
}
static int cqspi_versal_indirect_read_dma(struct cqspi_flash_pdata *f_pdata,
u_char *rxbuf, loff_t from_addr,
size_t n_rx)
@ -815,10 +830,14 @@ static int cqspi_versal_indirect_read_dma(struct cqspi_flash_pdata *f_pdata,
if (ret)
return ret;
cqspi_controller_enable(cqspi, 0);
reg = readl(cqspi->iobase + CQSPI_REG_CONFIG);
reg |= CQSPI_REG_CONFIG_DMA_MASK;
writel(reg, cqspi->iobase + CQSPI_REG_CONFIG);
cqspi_controller_enable(cqspi, 1);
dma_addr = dma_map_single(dev, rxbuf, bytes_to_dma, DMA_FROM_DEVICE);
if (dma_mapping_error(dev, dma_addr)) {
dev_err(dev, "dma mapping failed\n");
@ -876,10 +895,14 @@ static int cqspi_versal_indirect_read_dma(struct cqspi_flash_pdata *f_pdata,
cqspi->iobase + CQSPI_REG_INDIRECTRD);
dma_unmap_single(dev, dma_addr, bytes_to_dma, DMA_FROM_DEVICE);
cqspi_controller_enable(cqspi, 0);
reg = readl(cqspi->iobase + CQSPI_REG_CONFIG);
reg &= ~CQSPI_REG_CONFIG_DMA_MASK;
writel(reg, cqspi->iobase + CQSPI_REG_CONFIG);
cqspi_controller_enable(cqspi, 1);
ret = zynqmp_pm_ospi_mux_select(cqspi->pd_dev_id,
PM_OSPI_MUX_SEL_LINEAR);
if (ret)
@ -1182,21 +1205,6 @@ static void cqspi_readdata_capture(struct cqspi_st *cqspi,
writel(reg, reg_base + CQSPI_REG_READCAPTURE);
}
static void cqspi_controller_enable(struct cqspi_st *cqspi, bool enable)
{
void __iomem *reg_base = cqspi->iobase;
unsigned int reg;
reg = readl(reg_base + CQSPI_REG_CONFIG);
if (enable)
reg |= CQSPI_REG_CONFIG_ENABLE_MASK;
else
reg &= ~CQSPI_REG_CONFIG_ENABLE_MASK;
writel(reg, reg_base + CQSPI_REG_CONFIG);
}
static void cqspi_configure(struct cqspi_flash_pdata *f_pdata,
unsigned long sclk)
{