spi: cadence-qspi: Add direct mode support

[oweals/u-boot.git] / drivers / spi / spi-mem.c

diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c
index b86eee75bcb9b75f4ec6f9ec69eb2b71dca0f879..7788ab995344332a1280b196c52de652dd55de5a 100644 (file)
--- a/drivers/spi/spi-mem.c
+++ b/drivers/spi/spi-mem.c
@@ -201,7 +201,6 @@ int spi_mem_exec_op(struct spi_slave *slave, const struct spi_mem_op *op)
        unsigned int pos = 0;
        const u8 *tx_buf = NULL;
        u8 *rx_buf = NULL;
-       u8 *op_buf;
        int op_len;
        u32 flag;
        int ret;
@@ -338,7 +337,17 @@ int spi_mem_exec_op(struct spi_slave *slave, const struct spi_mem_op *op)
        }
 
        op_len = sizeof(op->cmd.opcode) + op->addr.nbytes + op->dummy.nbytes;
-       op_buf = calloc(1, op_len);
+
+       /*
+        * Avoid using malloc() here so that we can use this code in SPL where
+        * simple malloc may be used. That implementation does not allow free()
+        * so repeated calls to this code can exhaust the space.
+        *
+        * The value of op_len is small, since it does not include the actual
+        * data being sent, only the op-code and address. In fact, it should be
+        * possible to just use a small fixed value here instead of op_len.
+        */
+       u8 op_buf[op_len];
 
        op_buf[pos++] = op->cmd.opcode;
 
@@ -382,8 +391,6 @@ int spi_mem_exec_op(struct spi_slave *slave, const struct spi_mem_op *op)
                debug("%02x ", tx_buf ? tx_buf[i] : rx_buf[i]);
        debug("[ret %d]\n", ret);
 
-       free(op_buf);
-
        if (ret < 0)
                return ret;
 #endif /* __UBOOT__ */
@@ -423,12 +430,14 @@ int spi_mem_adjust_op_size(struct spi_slave *slave, struct spi_mem_op *op)
                if (slave->max_write_size && len > slave->max_write_size)
                        return -EINVAL;
 
-               if (op->data.dir == SPI_MEM_DATA_IN && slave->max_read_size)
-                       op->data.nbytes = min(op->data.nbytes,
+               if (op->data.dir == SPI_MEM_DATA_IN) {
+                       if (slave->max_read_size)
+                               op->data.nbytes = min(op->data.nbytes,
                                              slave->max_read_size);
-               else if (slave->max_write_size)
+               } else if (slave->max_write_size) {
                        op->data.nbytes = min(op->data.nbytes,
                                              slave->max_write_size - len);
+               }
 
                if (!op->data.nbytes)
                        return -EINVAL;