spi: spi-mtk-nor: add helper for checking prg mode ops

op checking/resizing logic for the newly added mtk_nor_spi_mem_prg is
more complicated. Add two helper functions for them:
mtk_nor_match_prg: check whether an op is supported by prg mode.
mtk_nor_adj_prg_size: adjust data size for mtk_nor_spi_mem_prg.

mtk_nor_match_prg isn't called yet because supports_op is currently
broken. It'll be used in the next fix commit.

Signed-off-by: Chuanhong Guo <gch981213@gmail.com>
Link: https://lore.kernel.org/r/20200924152730.733243-3-gch981213@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-mtk-nor.c b/drivers/spi/spi-mtk-nor.c
index a0087a5e869b96200ecd18cd9c181d6ae434c8bb..4bbf38ef5b4b1117e4c0d3971718e7f901d636f7 100644 (file)
--- a/drivers/spi/spi-mtk-nor.c
+++ b/drivers/spi/spi-mtk-nor.c
@@ -168,10 +168,76 @@ static bool mtk_nor_match_read(const struct spi_mem_op *op)
        return false;
 }
 
-static int mtk_nor_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op)
+static bool mtk_nor_match_prg(const struct spi_mem_op *op)
 {
-       size_t len;
+       int tx_len, rx_len, prg_len, prg_left;
+
+       // prg mode is spi-only.
+       if ((op->cmd.buswidth > 1) || (op->addr.buswidth > 1) ||
+           (op->dummy.buswidth > 1) || (op->data.buswidth > 1))
+               return false;
+
+       tx_len = op->cmd.nbytes + op->addr.nbytes;
+
+       if (op->data.dir == SPI_MEM_DATA_OUT) {
+               // count dummy bytes only if we need to write data after it
+               tx_len += op->dummy.nbytes;
+
+               // leave at least one byte for data
+               if (tx_len > MTK_NOR_REG_PRGDATA_MAX)
+                       return false;
+
+               // if there's no addr, meaning adjust_op_size is impossible,
+               // check data length as well.
+               if ((!op->addr.nbytes) &&
+                   (tx_len + op->data.nbytes > MTK_NOR_REG_PRGDATA_MAX + 1))
+                       return false;
+       } else if (op->data.dir == SPI_MEM_DATA_IN) {
+               if (tx_len > MTK_NOR_REG_PRGDATA_MAX + 1)
+                       return false;
+
+               rx_len = op->data.nbytes;
+               prg_left = MTK_NOR_PRG_CNT_MAX / 8 - tx_len - op->dummy.nbytes;
+               if (prg_left > MTK_NOR_REG_SHIFT_MAX + 1)
+                       prg_left = MTK_NOR_REG_SHIFT_MAX + 1;
+               if (rx_len > prg_left) {
+                       if (!op->addr.nbytes)
+                               return false;
+                       rx_len = prg_left;
+               }
+
+               prg_len = tx_len + op->dummy.nbytes + rx_len;
+               if (prg_len > MTK_NOR_PRG_CNT_MAX / 8)
+                       return false;
+       } else {
+               prg_len = tx_len + op->dummy.nbytes;
+               if (prg_len > MTK_NOR_PRG_CNT_MAX / 8)
+                       return false;
+       }
+       return true;
+}
 
+static void mtk_nor_adj_prg_size(struct spi_mem_op *op)
+{
+       int tx_len, tx_left, prg_left;
+
+       tx_len = op->cmd.nbytes + op->addr.nbytes;
+       if (op->data.dir == SPI_MEM_DATA_OUT) {
+               tx_len += op->dummy.nbytes;
+               tx_left = MTK_NOR_REG_PRGDATA_MAX + 1 - tx_len;
+               if (op->data.nbytes > tx_left)
+                       op->data.nbytes = tx_left;
+       } else if (op->data.dir == SPI_MEM_DATA_IN) {
+               prg_left = MTK_NOR_PRG_CNT_MAX / 8 - tx_len - op->dummy.nbytes;
+               if (prg_left > MTK_NOR_REG_SHIFT_MAX + 1)
+                       prg_left = MTK_NOR_REG_SHIFT_MAX + 1;
+               if (op->data.nbytes > prg_left)
+                       op->data.nbytes = prg_left;
+       }
+}
+
+static int mtk_nor_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op)
+{
        if (!op->data.nbytes)
                return 0;
 
@@ -200,11 +266,7 @@ static int mtk_nor_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op)
                }
        }
 
-       len = MTK_NOR_PRG_MAX_SIZE - op->cmd.nbytes - op->addr.nbytes -
-             op->dummy.nbytes;
-       if (op->data.nbytes > len)
-               op->data.nbytes = len;
-
+       mtk_nor_adj_prg_size(op);
        return 0;
 }