kernel.git/drivers/dma/sprd-dma.c, branch linux-5.18.y

dmaengine: sprd: stop referencing config->slave_id

2021-12-17T05:53:56Z

It appears that the code that reads the slave_id from the channel config was copied incorrectly from other drivers. Nothing ever sets this field on platforms that use this driver, so remove the reference. Reviewed-by: Baolin Wang Signed-off-by: Arnd Bergmann Acked-by: Mark Brown Link: https://lore.kernel.org/r/20211122222203.4103644-8-arnd@kernel.org Signed-off-by: Vinod Koul

dmaengine: sprd: Add missing MODULE_DEVICE_TABLE

2021-07-15T12:17:38Z

This patch adds missing MODULE_DEVICE_TABLE definition which generates correct modalias for automatic loading of this driver when it is built as an external module. Reported-by: Hulk Robot Signed-off-by: Zou Wei Reviewed-by: Baolin Wang Link: https://lore.kernel.org/r/1620094977-70146-1-git-send-email-zou_wei@huawei.com Signed-off-by: Vinod Koul

dmaengine: sprd: Set request pending flag when DMA controller is active

2020-03-23T06:08:24Z

On new Spreadtrum platforms, when the CPU enters idle, it will close the DMA controllers' clock to save power if the DMA controller is not busy. Moreover the DMA controller's busy signal depends on the DMA enable flag and the request pending flag. When DMA controller starts to transfer data, which means we already set the DMA enable flag, but now we should also set the request pending flag, in case the DMA clock will be closed accidentally if the CPU can not detect the DMA controller's busy signal. Signed-off-by: Zhenfang Wang Signed-off-by: Baolin Wang Link: https://lore.kernel.org/r/02adbe4364ec436ec2c5bc8fd2386bab98edd884.1584019223.git.baolin.wang7@gmail.com Signed-off-by: Vinod Koul

dmaengine: sprd: Replace zero-length array with flexible-array member

2020-02-19T12:18:40Z

The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva Reviewed-by: Baolin Wang Link: https://lore.kernel.org/r/20200214171536.GA24077@embeddedor Signed-off-by: Vinod Koul

dmaengine: sprd: Add wrap address support for link-list mode

2019-11-14T10:33:35Z

The Spreadtrum Audio compress offload mode will use 2-stage DMA transfer to save power. That means we can request 2 dma channels, one for source channel, and another one for destination channel. Once the source channel's transaction is done, it will trigger the destination channel's transaction automatically by hardware signal. In this case, the source channel will transfer data from IRAM buffer to the DSP fifo to decoding/encoding, once IRAM buffer is empty by transferring done, the destination channel will start to transfer data from DDR buffer to IRAM buffer. Since the destination channel will use link-list mode to fill the IRAM data, and IRAM buffer is allocated by 32K, and DDR buffer is larger to 2M, that means we need lots of link-list nodes to do a cyclic transfer, instead wasting lots of link-list memory, we can use wrap address support to reduce link-list node number, which means when the transfer address reaches the wrap address, the transfer address will jump to the wrap_to address specified by wrap_to register, and only 2 link-list nodes can do a cyclic transfer to transfer data from DDR to IRAM. Thus this patch adds wrap address to support this case. [Baolin Wang changes the commit message] Signed-off-by: Eric Long Signed-off-by: Baolin Wang Link: https://lore.kernel.org/r/85a5484bc1f3dd53ce6f92700ad8b35f30a0b096.1571812029.git.baolin.wang@linaro.org Signed-off-by: Vinod Koul

Merge branch 'fixes' into next

2019-11-14T10:32:51Z

dmaengine: sprd: Fix the possible memory leak issue

2019-10-15T10:17:24Z

If we terminate the channel to free all descriptors associated with this channel, we will leak the memory of current descriptor if the current descriptor is not completed, since it had been deteled from the desc_issued list and have not been added into the desc_completed list. Thus we should check if current descriptor is completed or not, when freeing the descriptors associated with one channel, if not, we should free it to avoid this issue. Fixes: 9b3b8171f7f4 ("dmaengine: sprd: Add Spreadtrum DMA driver") Reported-by: Zhenfang Wang Tested-by: Zhenfang Wang Signed-off-by: Baolin Wang Link: https://lore.kernel.org/r/170dbbc6d5366b6fa974ce2d366652e23a334251.1570609788.git.baolin.wang@linaro.org Signed-off-by: Vinod Koul

dmaengine: sprd: Change to use devm_platform_ioremap_resource()

2019-10-15T10:12:52Z

Use the new helper that wraps the calls to platform_get_resource() and devm_ioremap_resource() together, which can simpify the code. Signed-off-by: Baolin Wang Link: https://lore.kernel.org/r/1af3efdac3b217203cace090c8947386854c0144.1569554639.git.baolin.wang@linaro.org Signed-off-by: Vinod Koul

dmaengine: sprd: Fix the link-list pointer register configuration issue

2019-10-14T05:02:18Z

We will set the link-list pointer register point to next link-list configuration's physical address, which can load DMA configuration from the link-list node automatically. But the link-list node's physical address can be larger than 32bits, and now Spreadtrum DMA driver only supports 32bits physical address, which may cause loading a incorrect DMA configuration when starting the link-list transfer mode. According to the DMA datasheet, we can use SRC_BLK_STEP register (bit28 - bit31) to save the high bits of the link-list node's physical address to fix this issue. Fixes: 4ac695464763 ("dmaengine: sprd: Support DMA link-list mode") Signed-off-by: Zhenfang Wang Signed-off-by: Baolin Wang Link: https://lore.kernel.org/r/eadfe9295499efa003e1c344e67e2890f9d1d780.1568267061.git.baolin.wang@linaro.org Signed-off-by: Vinod Koul

dmaengine: sprd: Fix the DMA link-list configuration

2019-09-04T05:55:38Z

For the Spreadtrum DMA link-list mode, when the DMA engine got a slave hardware request, which will trigger the DMA engine to load the DMA configuration from the link-list memory automatically. But before the slave hardware request, the slave will get an incorrect residue due to the first node used to trigger the link-list was configured as the last source address and destination address. Thus we should make sure the first node was configured the start source address and destination address, which can fix this issue. Fixes: 4ac695464763 ("dmaengine: sprd: Support DMA link-list mode") Signed-off-by: Baolin Wang Link: https://lore.kernel.org/r/77868edb7aff9d5cb12ac3af8827ef2e244441a6.1567150471.git.baolin.wang@linaro.org Signed-off-by: Vinod Koul