Re: [PATCH 10/19] dma: imx-sdma: Add multi fifo support

On Fri, Mar 18, 2022 at 01:42:51PM +0800, Shengjiu Wang wrote:

Hi On Thu, Mar 17, 2022 at 4:28 PM Sascha Hauer <[1]s.hauer@pengutronix.de> wrote:

 Signed-off-by: Sascha Hauer <[2]s.hauer@pengutronix.de>
 ---
  drivers/dma/imx-sdma.c                | 54 +++++++++++++++++++++++++++
  include/linux/platform_data/dma-imx.h |  7 ++++
  2 files changed, 61 insertions(+)

 diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
 index 1038f6bc7f846..21e1cec2ffde9 100644
 --- a/drivers/dma/imx-sdma.c
 +++ b/drivers/dma/imx-sdma.c
 @@ -14,6 +14,7 @@
  #include <linux/iopoll.h>
  #include <linux/module.h>
  #include <linux/types.h>
 +#include <linux/bitfield.h>
  #include <linux/bitops.h>
  #include <linux/mm.h>
  #include <linux/interrupt.h>
 @@ -73,6 +74,7 @@
  #define SDMA_CHNENBL0_IMX35    0x200
  #define SDMA_CHNENBL0_IMX31    0x080
  #define SDMA_CHNPRI_0          0x100
 +#define SDMA_DONE0_CONFIG      0x1000

  /*
   * Buffer descriptor status values.
 @@ -180,6 +182,12 @@
                                  BIT(DMA_MEM_TO_DEV) | \
                                  BIT(DMA_DEV_TO_DEV))

 +#define SDMA_WATERMARK_LEVEL_N_FIFOS   GENMASK(15, 12)
 +#define SDMA_WATERMARK_LEVEL_SW_DONE   BIT(23)
 +
 +#define SDMA_DONE0_CONFIG_DONE_SEL     BIT(7)
 +#define SDMA_DONE0_CONFIG_DONE_DIS     BIT(6)
 +
  /**
   * struct sdma_script_start_addrs - SDMA script start pointers
   *
 @@ -441,6 +449,11 @@ struct sdma_channel {
         struct work_struct              terminate_worker;
         struct list_head                terminated;
         bool                            is_ram_script;
 +       unsigned int                    n_fifos;
 +       unsigned int                    n_fifos_src;
 +       unsigned int                    n_fifos_dst;
 +       bool                            sw_done;
 +       u32                             sw_done_sel;

"sw_done_sel" is not used, and may not be needed.

Ok, will drop.

And can we just add 'struct sdma_peripheral_config *pconfig' to replace each item here ('n_fifos_src', 'n_fifos_dst', 'sw_done')?

I rather do not access the pointer to the peripheral_config outside of sdma_config because I know nothing about the lifetime of that structure.

the pconfig can point to the struct in dma_slave_config. And 'n_fifos' can be moved to locally function in  sdma_set_watermarklevel_for_sais(), then use sdmac->direction to select 'n_fifos_dst' or 'n_fifos_src'.

Ok.

Sascha