Make ARM NAND I/O operations aware of last op

Updates the ARM NAND I/O code to look at and update the op
field of arm_nand_data to reflect the last operation performed.
It uses this field to copy the correct code to the target in the
case where the struct is used for reads and writes.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>

src/flash/arm_nandio.c

@@ -40,7 +40,8 @@
  * @param area Pointer to a pointer to a working area to copy code to
  * @return Success or failure of the operation
  */
-int arm_code_to_working_area(struct target *target, const uint32_t *code, unsigned code_size,
+int arm_code_to_working_area(struct target *target,
+		const uint32_t *code, unsigned code_size,
 		unsigned additional, struct working_area **area)
 {
 	uint8_t code_buf[code_size];
@@ -48,6 +49,11 @@ int arm_code_to_working_area(struct target *target, const uint32_t *code, unsign
 	int retval;
 	unsigned size = code_size + additional;
 
+	/* REVISIT this assumes size doesn't ever change.
+	 * That's usually correct; but there are boards with
+	 * both large and small page chips, where it won't be...
+	 */
+
 	/* make sure we have a working area */
 	if (NULL == *area) {
 		retval = target_alloc_working_area(target, size, area);
@@ -109,7 +115,7 @@ int arm_nandwrite(struct arm_nand_data *nand, uint8_t *data, int size)
 		0xe1200070,	/* e: bkpt  #0           */
 	};
 
-	if (!nand->copy_area) {
+	if (nand->op != ARM_NAND_WRITE || !nand->copy_area) {
 		retval = arm_code_to_working_area(target, code, sizeof(code),
 				nand->chunk_size, &nand->copy_area);
 		if (retval != ERROR_OK) {
@@ -117,6 +123,8 @@ int arm_nandwrite(struct arm_nand_data *nand, uint8_t *data, int size)
 		}
 	}
 
+	nand->op = ARM_NAND_WRITE;
+
 	/* copy data to work area */
 	target_buf = nand->copy_area->address + sizeof(code);
 	retval = target_bulk_write_memory(target, target_buf, size / 4, data);
@@ -192,7 +200,7 @@ int arm_nandread(struct arm_nand_data *nand, uint8_t *data, uint32_t size)
 	};
 
 	/* create the copy area if not yet available */
-	if (!nand->copy_area) {
+	if (nand->op != ARM_NAND_READ || !nand->copy_area) {
 		retval = arm_code_to_working_area(target, code, sizeof(code),
 				nand->chunk_size, &nand->copy_area);
 		if (retval != ERROR_OK) {
@@ -200,6 +208,7 @@ int arm_nandread(struct arm_nand_data *nand, uint8_t *data, uint32_t size)
 		}
 	}
 
+	nand->op = ARM_NAND_READ;
 	target_buf = nand->copy_area->address + sizeof(code);
 
 	/* set up algorithm and parameters */
@@ -223,7 +232,7 @@ int arm_nandread(struct arm_nand_data *nand, uint8_t *data, uint32_t size)
 	retval = target_run_algorithm(target, 0, NULL, 3, reg_params,
 			nand->copy_area->address, exit, 1000, &algo);
 	if (retval != ERROR_OK)
-		LOG_ERROR("error executing hosted NAND write");
+		LOG_ERROR("error executing hosted NAND read");
 
 	destroy_reg_param(&reg_params[0]);
 	destroy_reg_param(&reg_params[1]);