[PATCH v4 15/20] mtd: nand: qcom: support for command descriptor formation

Abhishek Sahu
2017-08-11T11:41:10Z

1. Add the function for command descriptor preparation which will
be used only by BAM DMA and it will form the DMA descriptors
containing command elements
2. DMA_PREP_CMD flag should be used for forming command DMA
descriptors

Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
---
drivers/mtd/nand/qcom_nandc.c | 108 +++++++++++++++++++++++++++++++++++-------
1 file changed, 92 insertions(+), 16 deletions(-)

diff --git a/drivers/mtd/nand/qcom_nandc.c b/drivers/mtd/nand/qcom_nandc.c
index d17c466..f2cb696 100644
--- a/drivers/mtd/nand/qcom_nandc.c
+++ b/drivers/mtd/nand/qcom_nandc.c
@@ -194,6 +194,14 @@
((size) << READ_LOCATION_SIZE) | \
((is_last) << READ_LOCATION_LAST))

+/* Returns the NAND register physical address */
+#define nandc_reg_phys(chip, offset) ((chip)->base_phys + (offset))
+
+/* Returns the dma address for reg read buffer */
+#define reg_buf_dma_addr(chip, vaddr) \
+ ((chip)->reg_read_dma + \
+ ((uint8_t *)(vaddr) - (uint8_t *)(chip)->reg_read_buf))
+
/* Returns the actual register address for NAND_FLASH_DEV_* */
#define nandc_dev_addr(nandc, reg) ((nandc)->props->flash_dev_offset + (reg))

@@ -311,7 +319,8 @@ struct nandc_regs {
* controller
* @dev: parent device
* @base: MMIO base
- * @base_dma: physical base address of controller registers
+ * @base_phys: physical base address of controller registers
+ * @base_dma: dma base address of controller registers
* @core_clk: controller clock
* @aon_clk: another controller clock
*
@@ -344,6 +353,7 @@ struct qcom_nand_controller {
struct device *dev;

void __iomem *base;
+ phys_addr_t base_phys;
dma_addr_t base_dma;

struct clk *core_clk;
@@ -745,6 +755,66 @@ static int prepare_bam_async_desc(struct qcom_nand_controller *nandc,
}

/*
+ * Prepares the command descriptor for BAM DMA which will be used for NAND
+ * register reads and writes. The command descriptor requires the command
+ * to be formed in command element type so this function uses the command
+ * element from bam transaction ce array and fills the same with required
+ * data. A single SGL can contain multiple command elements so
+ * NAND_BAM_NEXT_SGL will be used for starting the separate SGL
+ * after the current command element.
+ */
+static int prep_bam_dma_desc_cmd(struct qcom_nand_controller *nandc, bool read,
+ int reg_off, const void *vaddr,
+ int size, unsigned int flags)
+{
+ int bam_ce_size;
+ int i, ret;
+ struct bam_cmd_element *bam_ce_buffer;
+ struct bam_transaction *bam_txn = nandc->bam_txn;
+
+ bam_ce_buffer = &bam_txn->bam_ce[bam_txn->bam_ce_pos];
+
+ /* fill the command desc */
+ for (i = 0; i < size; i++) {
+ if (read)
+ bam_prep_ce(&bam_ce_buffer[i],
+ nandc_reg_phys(nandc, reg_off + 4 * i),
+ BAM_READ_COMMAND,
+ reg_buf_dma_addr(nandc,
+ (__le32 *)vaddr + i));
+ else
+ bam_prep_ce_le32(&bam_ce_buffer[i],
+ nandc_reg_phys(nandc, reg_off + 4 * i),
+ BAM_WRITE_COMMAND,
+ *((__le32 *)vaddr + i));
+ }
+
+ bam_txn->bam_ce_pos += size;
+
+ /* use the separate sgl after this command */
+ if (flags & NAND_BAM_NEXT_SGL) {
+ bam_ce_buffer = &bam_txn->bam_ce[bam_txn->bam_ce_start];
+ bam_ce_size = (bam_txn->bam_ce_pos -
+ bam_txn->bam_ce_start) *
+ sizeof(struct bam_cmd_element);
+ sg_set_buf(&bam_txn->cmd_sgl[bam_txn->cmd_sgl_pos],
+ bam_ce_buffer, bam_ce_size);
+ bam_txn->cmd_sgl_pos++;
+ bam_txn->bam_ce_start = bam_txn->bam_ce_pos;
+
+ if (flags & NAND_BAM_NWD) {
+ ret = prepare_bam_async_desc(nandc, nandc->cmd_chan,
+ DMA_PREP_FENCE |
+ DMA_PREP_CMD);
+ if (ret)
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+/*
* Prepares the data descriptor for BAM DMA which will be used for NAND
* data reads and writes.
*/
@@ -861,19 +931,22 @@ static int read_reg_dma(struct qcom_nand_controller *nandc, int first,
{
bool flow_control = false;
void *vaddr;
- int size;

- if (first == NAND_READ_ID || first == NAND_FLASH_STATUS)
- flow_control = true;
+ vaddr = nandc->reg_read_buf + nandc->reg_read_pos;
+ nandc->reg_read_pos += num_regs;

if (first == NAND_DEV_CMD_VLD || first == NAND_DEV_CMD1)
first = nandc_dev_addr(nandc, first);

- size = num_regs * sizeof(u32);
- vaddr = nandc->reg_read_buf + nandc->reg_read_pos;
- nandc->reg_read_pos += num_regs;
+ if (nandc->props->is_bam)
+ return prep_bam_dma_desc_cmd(nandc, true, first, vaddr,
+ num_regs, flags);

- return prep_adm_dma_desc(nandc, true, first, vaddr, size, flow_control);
+ if (first == NAND_READ_ID || first == NAND_FLASH_STATUS)
+ flow_control = true;
+
+ return prep_adm_dma_desc(nandc, true, first, vaddr,
+ num_regs * sizeof(u32), flow_control);
}

/*
@@ -889,13 +962,9 @@ static int write_reg_dma(struct qcom_nand_controller *nandc, int first,
bool flow_control = false;
struct nandc_regs *regs = nandc->regs;
void *vaddr;
- int size;

vaddr = offset_to_nandc_reg(regs, first);

- if (first == NAND_FLASH_CMD)
- flow_control = true;
-
if (first == NAND_ERASED_CW_DETECT_CFG) {
if (flags & NAND_ERASED_CW_SET)
vaddr = &regs->erased_cw_detect_cfg_set;
@@ -912,10 +981,15 @@ static int write_reg_dma(struct qcom_nand_controller *nandc, int first,
if (first == NAND_DEV_CMD_VLD_RESTORE || first == NAND_DEV_CMD_VLD)
first = nandc_dev_addr(nandc, NAND_DEV_CMD_VLD);

- size = num_regs * sizeof(u32);
+ if (nandc->props->is_bam)
+ return prep_bam_dma_desc_cmd(nandc, false, first, vaddr,
+ num_regs, flags);
+
+ if (first == NAND_FLASH_CMD)
+ flow_control = true;

- return prep_adm_dma_desc(nandc, false, first, vaddr, size,
- flow_control);
+ return prep_adm_dma_desc(nandc, false, first, vaddr,
+ num_regs * sizeof(u32), flow_control);
}

/*
@@ -1177,7 +1251,8 @@ static int submit_descs(struct qcom_nand_controller *nandc)
}

if (bam_txn->cmd_sgl_pos > bam_txn->cmd_sgl_start) {
- r = prepare_bam_async_desc(nandc, nandc->cmd_chan, 0);
+ r = prepare_bam_async_desc(nandc, nandc->cmd_chan,
+ DMA_PREP_CMD);
if (r)
return r;
}
@@ -2713,6 +2788,7 @@ static int qcom_nandc_probe(struct platform_device *pdev)
if (IS_ERR(nandc->base))
return PTR_ERR(nandc->base);

+ nandc->base_phys = res->start;
nandc->base_dma = phys_to_dma(dev, (phys_addr_t)res->start);

nandc->core_clk = devm_clk_get(dev, "core");