[v10,14/27] mtd: spi-nor-core: Add support for DTR protocol

[jaimeliao at mxic.com.tw]

Hi Pratyush


In the [v10,14/27]
@@ -2767,7 +2858,10 @@  int spi_nor_scan(struct spi_nor *nor)
                 if (ret)
                                 return ret;
 
-                if (nor->addr_width) {
+                if (spi_nor_protocol_is_dtr(nor->read_proto)) {
+                                 /* Always use 4-byte addresses in DTR 
mode. */
+                                nor->addr_width = 4;
+                } else if (nor->addr_width) {
                                 /* already configured from SFDP */
                 } else if (info->addr_width) {
                                 nor->addr_width = info->addr_width;

In the [v10,8/27]

@@ -2603,7 +2603,11 @@  int spi_nor_scan(struct spi_nor *nor)
                                 /* already configured from SFDP */
                 } else if (info->addr_width) {
                                 nor->addr_width = info->addr_width;
-                } else if (mtd->size > SZ_16M) {
+                } else {
+                                nor->addr_width = 3;
+                }
+
+                if (nor->addr_width == 3 && mtd->size > SZ_16M) {
 #ifndef CONFIG_SPI_FLASH_BAR
                                 /* enable 4-byte addressing if the device 
exceeds 16MiB */
                                 nor->addr_width = 4;


For this part, nor->addr_width will be set to 4 if spi-nor protocol is DTR 
mode.
Judgement "if (nor->addr_width == 3 && mtd->size > SZ_16M)" will not be 
triggered
and spi_nor_set_4byte_opcodes will not execute. So that driver still using 
3-bytes
opcode in DTR mode. I think it is not convenient for every flash vendors 
to add 
xxx_post_sfdp_fixup() for setting pp and erase opcode in different 
protocol.
Would you consider to follow the linux method?


Thanks
Jaime

CONFIDENTIALITY NOTE:

This e-mail and any attachments may contain confidential information 
and/or personal data, which is protected by applicable laws. Please be 
reminded that duplication, disclosure, distribution, or use of this e-mail 
(and/or its attachments) or any part thereof is prohibited. If you receive 
this e-mail in error, please notify us immediately and delete this mail as 
well as its attachment(s) from your system. In addition, please be 
informed that collection, processing, and/or use of personal data is 
prohibited unless expressly permitted by personal data protection laws. 
Thank you for your attention and cooperation.

Macronix International Co., Ltd.

=====================================================================



============================================================================

CONFIDENTIALITY NOTE:

This e-mail and any attachments may contain confidential information and/or personal data, which is protected by applicable laws. Please be reminded that duplication, disclosure, distribution, or use of this e-mail (and/or its attachments) or any part thereof is prohibited. If you receive this e-mail in error, please notify us immediately and delete this mail as well as its attachment(s) from your system. In addition, please be informed that collection, processing, and/or use of personal data is prohibited unless expressly permitted by personal data protection laws. Thank you for your attention and cooperation.

Macronix International Co., Ltd.

=====================================================================