[PATCH v4 10/11] mtd: spi-nor: core: Introduce spi_nor_set_4byte_addr_mode()

[Tudor Ambarus]

Make the method public, as it will be used as a last resort to enable
4byte address mode when we can't determine the address mode at runtime.
Update the addr_nbytes and current address mode while exiting the 4byte
address mode too, as it may be used in the future by manufacturer
drivers. No functional change. spi_nor_restore didn't update the address
mode nbytes, but updating them now doesn't harm as the method is called
in the driver's remove and shutdown paths.

Signed-off-by: Tudor Ambarus <tudor.ambarus at linaro.org>
---
 drivers/mtd/spi-nor/core.c | 35 ++++++++++++++++++++++++++++++-----
 drivers/mtd/spi-nor/core.h |  1 +
 2 files changed, 31 insertions(+), 5 deletions(-)

diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index 868414017399..4b2a6697a192 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -2767,9 +2767,35 @@ static int spi_nor_quad_enable(struct spi_nor *nor)
 	return nor->params->quad_enable(nor);
 }
 
-static int spi_nor_init(struct spi_nor *nor)
+/**
+ * spi_nor_set_4byte_addr_mode() - Set address mode.
+ * @nor:                pointer to a 'struct spi_nor'.
+ * @enable:             enable/disable 4 byte address mode.
+ *
+ * Return: 0 on success, -errno otherwise.
+ */
+int spi_nor_set_4byte_addr_mode(struct spi_nor *nor, bool enable)
 {
 	struct spi_nor_flash_parameter *params = nor->params;
+	int ret;
+
+	ret = params->set_4byte_addr_mode(nor, enable);
+	if (ret && ret != -ENOTSUPP)
+		return ret;
+
+	if (enable) {
+		params->addr_nbytes = 4;
+		params->addr_mode_nbytes = 4;
+	} else {
+		params->addr_nbytes = 3;
+		params->addr_mode_nbytes = 3;
+	}
+
+	return 0;
+}
+
+static int spi_nor_init(struct spi_nor *nor)
+{
 	int err;
 
 	err = spi_nor_octal_dtr_enable(nor, true);
@@ -2811,10 +2837,9 @@ static int spi_nor_init(struct spi_nor *nor)
 		 */
 		WARN_ONCE(nor->flags & SNOR_F_BROKEN_RESET,
 			  "enabling reset hack; may not recover from unexpected reboots\n");
-		err = params->set_4byte_addr_mode(nor, true);
-		if (err && err != -ENOTSUPP)
+		err = spi_nor_set_4byte_addr_mode(nor, true);
+		if (err)
 			return err;
-		params->addr_mode_nbytes = 4;
 	}
 
 	return 0;
@@ -2933,7 +2958,7 @@ static void spi_nor_restore(struct spi_nor *nor)
 	/* restore the addressing mode */
 	if (nor->addr_nbytes == 4 && !(nor->flags & SNOR_F_4B_OPCODES) &&
 	    nor->flags & SNOR_F_BROKEN_RESET) {
-		ret = nor->params->set_4byte_addr_mode(nor, false);
+		ret = spi_nor_set_4byte_addr_mode(nor, false);
 		if (ret)
 			/*
 			 * Do not stop the execution in the hope that the flash
diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h
index 394d251450f7..7152688d3985 100644
--- a/drivers/mtd/spi-nor/core.h
+++ b/drivers/mtd/spi-nor/core.h
@@ -638,6 +638,7 @@ int spi_nor_set_4byte_addr_mode_en4b_ex4b(struct spi_nor *nor, bool enable);
 int spi_nor_set_4byte_addr_mode_wren_en4b_ex4b(struct spi_nor *nor,
 					       bool enable);
 int spi_nor_set_4byte_addr_mode_brwr(struct spi_nor *nor, bool enable);
+int spi_nor_set_4byte_addr_mode(struct spi_nor *nor, bool enable);
 int spi_nor_wait_till_ready(struct spi_nor *nor);
 int spi_nor_global_block_unlock(struct spi_nor *nor);
 int spi_nor_lock_and_prep(struct spi_nor *nor);
-- 
2.40.0.rc1.284.g88254d51c5-goog