@@ -231,19 +231,22 @@ static int rtl_snand_xfer(struct rtl_snand *snand, int cs, const struct spi_mem_
static int rtl_snand_dma_xfer(struct rtl_snand *snand, int cs, const struct spi_mem_op *op)
{
+ unsigned int pos, nbytes;
int ret;
dma_addr_t buf_dma;
enum dma_data_direction dir;
- u32 trig;
+ u32 trig, len, maxlen;
ret = rtl_snand_xfer_head(snand, cs, op);
if (ret)
goto out_deselect;
if (op->data.dir == SPI_MEM_DATA_IN) {
+ maxlen = 2080;
dir = DMA_FROM_DEVICE;
trig = 0;
} else if (op->data.dir == SPI_MEM_DATA_OUT) {
+ maxlen = 520;
dir = DMA_TO_DEVICE;
trig = 1;
} else {
@@ -264,26 +267,37 @@ static int rtl_snand_dma_xfer(struct rtl_snand *snand, int cs, const struct spi_
if (ret)
goto out_unmap;
- reinit_completion(&snand->comp);
+ pos = 0;
+ len = op->data.nbytes;
- ret = regmap_write(snand->regmap, SNAFDRSAR, buf_dma);
- if (ret)
- goto out_disable_int;
+ while (pos < len) {
+ nbytes = len - pos;
+ if (nbytes > maxlen)
+ nbytes = maxlen;
- ret = regmap_write(snand->regmap, SNAFDLR,
- CMR_WID(op->data.buswidth) | (op->data.nbytes & 0xffff));
- if (ret)
- goto out_disable_int;
+ reinit_completion(&snand->comp);
- ret = regmap_write(snand->regmap, SNAFDTR, trig);
- if (ret)
- goto out_disable_int;
+ ret = regmap_write(snand->regmap, SNAFDRSAR, buf_dma + pos);
+ if (ret)
+ goto out_disable_int;
- if (!wait_for_completion_timeout(&snand->comp, usecs_to_jiffies(20000)))
- ret = -ETIMEDOUT;
+ pos += nbytes;
- if (ret)
- goto out_disable_int;
+ ret = regmap_write(snand->regmap, SNAFDLR,
+ CMR_WID(op->data.buswidth) | nbytes);
+ if (ret)
+ goto out_disable_int;
+
+ ret = regmap_write(snand->regmap, SNAFDTR, trig);
+ if (ret)
+ goto out_disable_int;
+
+ if (!wait_for_completion_timeout(&snand->comp, usecs_to_jiffies(20000)))
+ ret = -ETIMEDOUT;
+
+ if (ret)
+ goto out_disable_int;
+ }
out_disable_int:
regmap_update_bits(snand->regmap, SNAFCFR, SNAFCFR_DMA_IE, 0);
The RTL9300 has some limitations on the maximum DMA transfers possible. For reads this is 2080 bytes (520*4) for writes this is 520 bytes. Deal with this by splitting transfers into appropriately sized parts. Fixes: 42d20a6a61b8 ("spi: spi-mem: Add Realtek SPI-NAND controller") Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz> --- Notes: Changes in v2: - Drop unecessary "also" change. data.in and data.out point to the same memory but the latter is marked as const which causes some compiler warnings when we're trying to get a dma mapping for it. drivers/spi/spi-realtek-rtl-snand.c | 46 +++++++++++++++++++---------- 1 file changed, 30 insertions(+), 16 deletions(-)