Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-10 14:11:52 +00:00
Code Issues Packages Projects Releases Wiki Activity

spi: cadence-quadspi: Disable Auto-HW polling

Browse Source 
cadence-quadspi has a builtin Auto-HW polling funtionality using which
it keep tracks of completion of write operations. When Auto-HW polling
is enabled, it automatically initiates status register read operation,
until the flash clears its busy bit.

cadence-quadspi controller doesn't allow an address phase when
auto-polling the busy bit on the status register. Unlike SPI NOR
flashes, SPI NAND flashes do require the address of status register
when polling the busy bit using the read register operation. As
Auto-HW polling is enabled by default, cadence-quadspi returns a
timeout for every write operation after an indefinite amount of
polling on SPI NAND flashes.

Disable Auto-HW polling completely as the spi-nor core, spinand core,
etc. take care of polling the busy bit on their own.

Signed-off-by: Apurva Nandan <a-nandan@ti.com>
Link: https://lore.kernel.org/r/20210713125743.1540-2-a-nandan@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Apurva Nandan 2021-07-13 12:57:41 +00:00 committed by Mark Brown
parent 0e85ee8978
commit 9cb2ff1117
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
1 changed files with 14 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
drivers/spi/spi-cadence-quadspi.c
View File

@ -800,19 +800,20 @@ static int cqspi_write_setup(struct cqspi_flash_pdata *f_pdata,
reg = cqspi_calc_rdreg(f_pdata);
writel(reg, reg_base + CQSPI_REG_RD_INSTR);
if (f_pdata->dtr) {
/*
* Some flashes like the cypress Semper flash expect a 4-byte
* dummy address with the Read SR command in DTR mode, but this
* controller does not support sending address with the Read SR
* command. So, disable write completion polling on the
* controller's side. spi-nor will take care of polling the
* status register.
*/
reg = readl(reg_base + CQSPI_REG_WR_COMPLETION_CTRL);
reg |= CQSPI_REG_WR_DISABLE_AUTO_POLL;
writel(reg, reg_base + CQSPI_REG_WR_COMPLETION_CTRL);
}
/*
* SPI NAND flashes require the address of the status register to be
* passed in the Read SR command. Also, some SPI NOR flashes like the
* cypress Semper flash expect a 4-byte dummy address in the Read SR
* command in DTR mode.
*
* But this controller does not support address phase in the Read SR
* command when doing auto-HW polling. So, disable write completion
* polling on the controller's side. spinand and spi-nor will take
* care of polling the status register.
*/
reg = readl(reg_base + CQSPI_REG_WR_COMPLETION_CTRL);
reg |= CQSPI_REG_WR_DISABLE_AUTO_POLL;
writel(reg, reg_base + CQSPI_REG_WR_COMPLETION_CTRL);
reg = readl(reg_base + CQSPI_REG_SIZE);
reg &= ~CQSPI_REG_SIZE_ADDRESS_MASK;