The reference manual from Rockchip claims this about the BSF (SPI Busy
Flag):
* 0 - SPI is idle or disabled
* 1 - SPI is actively transferring data
The above doesn't quite appear to be true. Specifically I found the
busy bit set when SPI was disabled. Let's change the WARN_ON() so we
only check the busy bit if the controller was enabled.
Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
The wait_for_idle() could get unlucky and timeout too quickly.
Specifically, the old calculation was effectively:
timeout = jiffies + 1;
if (jiffies >= timeout) print warning;
From the above it should be obvious that if jiffies ticks in just the
wrong place then we'll have an effective timeout of 0.
Fix this by effectively changing the above ">=" to a ">". That gives
us an extra jiffy to finish.
Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
If our client is requesting a clock that is above the maximum clock
then the following division will result in 0:
rs->max_freq / rs->speed
We'll then program 0 into the SPI_BAUDR register. The Rockchip TRM
says: "If the value is 0, the serial output clock (sclk_out) is
disabled."
It's much better to end up with the fastest possible clock rather than
a clock that is off, so enforce a minimum value.
Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Fix to return -EINVAL from the error handling case instead of 0 when
failed to get fifo length.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Mark Brown <broonie@linaro.org>
There is a error message within devm_ioremap_resource
already, so remove the dev_err call to avoid redundant
error message.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Mark Brown <broonie@linaro.org>
In order to facilitate understanding, rockchip SPI controller IP design
looks similar in its registers to designware. But IC implementation
is different from designware, So we need a dedicated driver for Rockchip
RK3XXX SoCs integrated SPI. The main differences:
- dma request line: rockchip SPI controller have two DMA request line
for tx and rx.
- Register offset:
RK3288 dw
SPI_CTRLR0 0x0000 0x0000
SPI_CTRLR1 0x0004 0x0004
SPI_SSIENR 0x0008 0x0008
SPI_MWCR NONE 0x000c
SPI_SER 0x000c 0x0010
SPI_BAUDR 0x0010 0x0014
SPI_TXFTLR 0x0014 0x0018
SPI_RXFTLR 0x0018 0x001c
SPI_TXFLR 0x001c 0x0020
SPI_RXFLR 0x0020 0x0024
SPI_SR 0x0024 0x0028
SPI_IPR 0x0028 NONE
SPI_IMR 0x002c 0x002c
SPI_ISR 0x0030 0x0030
SPI_RISR 0x0034 0x0034
SPI_TXOICR NONE 0x0038
SPI_RXOICR NONE 0x003c
SPI_RXUICR NONE 0x0040
SPI_MSTICR NONE 0x0044
SPI_ICR 0x0038 0x0048
SPI_DMACR 0x003c 0x004c
SPI_DMATDLR 0x0040 0x0050
SPI_DMARDLR 0x0044 0x0054
SPI_TXDR 0x0400 NONE
SPI_RXDR 0x0800 NONE
SPI_IDR NONE 0x0058
SPI_VERSION NONE 0x005c
SPI_DR NONE 0x0060
- register configuration:
such as SPI_CTRLRO in rockchip SPI controller:
cr0 = (CR0_BHT_8BIT << CR0_BHT_OFFSET)
| (CR0_SSD_ONE << CR0_SSD_OFFSET);
cr0 |= (rs->n_bytes << CR0_DFS_OFFSET);
cr0 |= ((rs->mode & 0x3) << CR0_SCPH_OFFSET);
cr0 |= (rs->tmode << CR0_XFM_OFFSET);
cr0 |= (rs->type << CR0_FRF_OFFSET);
For more information, see RK3288 chip manual.
- Wait for idle: Must ensure that the FIFO data has been sent out
before the next transfer.
Signed-off-by: addy ke <addy.ke@rock-chips.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
