Using a static variable for counting the number of CCWs attached to
a DMA channel when appending a new descriptor is not multi user safe.
Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
There is no need to have the clock enabled all the time the driver is
loaded.
It will be enabled anyway in mxs_dma_alloc_chan_resources() when a
channel is actually going to be used.
Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
After calling mxs_dma_disable_chan() for a channel, that channel
becomes unusable because some controller registers can only be written
when the clock is enabled via CLKGATE.
Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
We met some channels in abnormal state after disable.
Reset it to get a clean state.
Signed-off-by: Dong Aisheng <b29396@freescale.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
In general, the mxs-dma users get separate irq for each channel,
but gpmi is special one which has only one irq shared by all gpmi
channels. It causes mxs_dma channel allocation function fail for
all other gpmi channels except the first one calling into the
function.
The patch gets request_irq call skipped for NO_IRQ case, and leaves
this gpmi specific quirk to gpmi driver to sort out. It will fix
above problem if gpmi driver sets chan_irq as gpmi irq for only one
channel and NO_IRQ for all the rest channels.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Cc: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
This patch adds dma support for Freescale MXS-based SoC i.MX23/28,
including apbh-dma and apbx-dma.
* apbh-dma and apbx-dma are supported in the driver as two mxs-dma
instances.
* apbh-dma is different between mx23 and mx28, hardware version
register is used to differentiate.
* mxs-dma supports pio function besides data transfer. The driver
uses dma_data_direction DMA_NONE to identify the pio mode, and
steals sgl and sg_len to get pio words and numbers from clients.
* mxs dmaengine has some very specific features, like sense function
and the special NAND support (nand_lock, nand_wait4ready). These
are too specific to implemented in generic dmaengine driver.
* The driver refers to imx-sdma and only a single descriptor is
statically assigned to each channel.
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Lothar Waßmann
Vinod Koul
Dong Aisheng
Axel Lin
Shawn Guo
Shawn Guo