On 2017-07-10 19:40, Sricharan R wrote:
Hi,
On 7/4/2017 12:19 PM, Archit Taneja wrote:
On 06/29/2017 12:45 PM, Abhishek Sahu wrote:
The BAM has multiple flags to control the transfer. This patch
adds flags parameter in register and data transfer functions and
modifies all these function call with appropriate flags.
Signed-off-by: Abhishek Sahu <absahu@xxxxxxxxxxxxxx>
---
drivers/mtd/nand/qcom_nandc.c | 114
++++++++++++++++++++++++------------------
1 file changed, 65 insertions(+), 49 deletions(-)
diff --git a/drivers/mtd/nand/qcom_nandc.c
b/drivers/mtd/nand/qcom_nandc.c
index 7042a65..65c9059 100644
--- a/drivers/mtd/nand/qcom_nandc.c
+++ b/drivers/mtd/nand/qcom_nandc.c
@@ -170,6 +170,14 @@
#define ECC_BCH_4BIT BIT(2)
#define ECC_BCH_8BIT BIT(3)
+/* Flags used for BAM DMA desc preparation*/
+/* Don't set the EOT in current tx sgl */
+#define NAND_BAM_NO_EOT (0x0001)
+/* Set the NWD flag in current sgl */
+#define NAND_BAM_NWD (0x0002)
+/* Finish writing in the current sgl and start writing in another
sgl */
+#define NAND_BAM_NEXT_SGL (0x0004)
+
#define QPIC_PER_CW_MAX_CMD_ELEMENTS (32)
#define QPIC_PER_CW_MAX_CMD_SGL (32)
#define QPIC_PER_CW_MAX_DATA_SGL (8)
I will remove the braces and use the bit macros.
@@ -712,7 +720,7 @@ static int prep_dma_desc(struct
qcom_nand_controller
*nandc, bool read,
* @num_regs: number of registers to read
*/
static int read_reg_dma(struct qcom_nand_controller *nandc, int
first,
- int num_regs)
+ int num_regs, unsigned int flags)
{
bool flow_control = false;
void *vaddr;
@@ -736,7 +744,7 @@ static int read_reg_dma(struct
qcom_nand_controller
*nandc, int first,
* @num_regs: number of registers to write
*/
static int write_reg_dma(struct qcom_nand_controller *nandc, int
first,
- int num_regs)
+ int num_regs, unsigned int flags)
Adding flags to read_reg_dma and write_reg_dma is making things a bit
messy. I can't
think of a better way to share the code either, though.
One thing we could consider doing is something like below. I don't
know if
it would
make things more legible.
union nand_dma_props {
bool adm_flow_control;
unsigned int bam_flags;
};
config_cw_read()
{
union nand_dma_props dma_props;
...
...
if (is_bam)
dma_props.bam_flags = NAND_BAM_NWD;
else
dma_props.adm_flow_control = false;
write_reg_dma(nandc, NAND_EXEC_CMD, 1, &dma_props);
...
...
}
The flags for each write_reg_dma and read_reg_dma will be different.
Normally, for all the API's which uses flags
(like dmaengine_prep_slave_sg), we are passing the flags directly.
this union won't help us making this code more readable.
Right, with this , i think we can have two different indirections for
functions like,
prep_dma_desc_command and prep_dma_desc. That will help to reduce the
bam_dma_enabled
checks.
Since common code changes are intermixed with bam_dma_enabled check
so taking function pointer won't help much in making code more
readable.
anyway, I will analyze the final code for v2 and will check the
possibility of using function pointers.
Regards,
Sricharan
--
Abhishek Sahu
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