mtd: spi: nor: force mtd name to "nor%d"

Force the mtd name of spi-nor to "nor" + the driver sequence number:
"nor0", "nor1"... beginning after the existing nor devices.

This patch is coherent with existing "nand" and "spi-nand"
mtd device names.

When CFI MTD NOR device are supported, the spi-nor index is chosen after
the last CFI device defined by CONFIG_SYS_MAX_FLASH_BANKS.

When CONFIG_SYS_MAX_FLASH_BANKS_DETECT is activated, this config
is replaced by to cfi_flash_num_flash_banks in the include file
mtd/cfi_flash.h.

This generic name "nor%d" can be use to identify the mtd spi-nor device
without knowing the real device name or the DT path of the device,
used with API get_mtd_device_nm() and is used in mtdparts command.

This patch also avoids issue when the same NOR device is present 2 times,
for example on STM32MP15F-EV1:

STM32MP> mtd list
SF: Detected mx66l51235l with page size 256 Bytes, erase size 64 KiB, \
total 64 MiB

List of MTD devices:
* nand0
  - type: NAND flash
  - block size: 0x40000 bytes
  - min I/O: 0x1000 bytes
  - OOB size: 224 bytes
  - OOB available: 118 bytes
  - ECC strength: 8 bits
  - ECC step size: 512 bytes
  - bitflip threshold: 6 bits
  - 0x000000000000-0x000040000000 : "nand0"
* mx66l51235l
  - device: mx66l51235l@0
  - parent: spi@58003000
  - driver: jedec_spi_nor
  - path: /soc/spi@58003000/mx66l51235l@0
  - type: NOR flash
  - block size: 0x10000 bytes
  - min I/O: 0x1 bytes
  - 0x000000000000-0x000004000000 : "mx66l51235l"
* mx66l51235l
  - device: mx66l51235l@1
  - parent: spi@58003000
  - driver: jedec_spi_nor
  - path: /soc/spi@58003000/mx66l51235l@1
  - type: NOR flash
  - block size: 0x10000 bytes
  - min I/O: 0x1 bytes
  - 0x000000000000-0x000004000000 : "mx66l51235l"

The same mtd name "mx66l51235l" identify the 2 instances
mx66l51235l@0 and mx66l51235l@1.

This patch fixes a ST32CubeProgrammer / stm32prog command issue
with nor0 target on STM32MP157C-EV1 board introduced by
commit b7f060565e ("mtd: spi-nor: allow registering multiple MTDs when
DM is enabled").

Fixes: b7f060565e ("mtd: spi-nor: allow registering multiple MTDs when DM is enabled")
Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
[trini: Add <dm/device.h> to <mtd.h> for DM_MAX_SEQ_STR]
Signed-off-by: Tom Rini <trini@konsulko.com>

drivers/mtd/spi/spi-nor-core.c

@@ -10,6 +10,7 @@
  */
 
 #include <common.h>
+#include <flash.h>
 #include <log.h>
 #include <watchdog.h>
 #include <dm.h>
@@ -26,6 +27,7 @@
 
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/spi-nor.h>
+#include <mtd/cfi_flash.h>
 #include <spi-mem.h>
 #include <spi.h>
 
@@ -3664,6 +3666,11 @@ int spi_nor_scan(struct spi_nor *nor)
 	struct mtd_info *mtd = &nor->mtd;
 	struct spi_slave *spi = nor->spi;
 	int ret;
+	int cfi_mtd_nb = 0;
+
+#ifdef CONFIG_SYS_MAX_FLASH_BANKS
+	cfi_mtd_nb = CONFIG_SYS_MAX_FLASH_BANKS;
+#endif
 
 	/* Reset SPI protocol for all commands. */
 	nor->reg_proto = SNOR_PROTO_1_1_1;
@@ -3715,8 +3722,12 @@ int spi_nor_scan(struct spi_nor *nor)
 	if (ret)
 		return ret;
 
-	if (!mtd->name)
+	if (!mtd->name) {
-		mtd->name = info->name;
+		sprintf(nor->mtd_name, "%s%d",
+			MTD_DEV_TYPE(MTD_DEV_TYPE_NOR),
+			cfi_mtd_nb + dev_seq(nor->dev));
+		mtd->name = nor->mtd_name;
+	}
 	mtd->dev = nor->dev;
 	mtd->priv = nor;
 	mtd->type = MTD_NORFLASH;
@@ -3821,7 +3832,7 @@ int spi_nor_scan(struct spi_nor *nor)
 
 	nor->rdsr_dummy = params.rdsr_dummy;
 	nor->rdsr_addr_nbytes = params.rdsr_addr_nbytes;
-	nor->name = mtd->name;
+	nor->name = info->name;
 	nor->size = mtd->size;
 	nor->erase_size = mtd->erasesize;
 	nor->sector_size = mtd->erasesize;

include/dm/device.h

@@ -207,8 +207,9 @@ struct udevice_rt {
 	u32 flags_;
 };
 
-/* Maximum sequence number supported */
+/* Maximum sequence number supported and associated string length */
 #define DM_MAX_SEQ	999
+#define DM_MAX_SEQ_STR	3
 
 /* Returns the operations for a device */
 #define device_get_ops(dev)	(dev->driver->ops)

include/linux/mtd/spi-nor.h

@@ -7,6 +7,7 @@
 #ifndef __LINUX_MTD_SPI_NOR_H
 #define __LINUX_MTD_SPI_NOR_H
 
+#include <mtd.h>
 #include <linux/bitops.h>
 #include <linux/mtd/cfi.h>
 #include <linux/mtd/mtd.h>
@@ -561,6 +562,7 @@ struct spi_nor {
 	int (*ready)(struct spi_nor *nor);
 
 	void *priv;
+	char mtd_name[MTD_NAME_SIZE(MTD_DEV_TYPE_NOR)];
 /* Compatibility for spi_flash, remove once sf layer is merged with mtd */
 	const char *name;
 	u32 size;

include/mtd.h

@@ -6,10 +6,15 @@
 #ifndef _MTD_H_
 #define _MTD_H_
 
+#include <dm/device.h>
+#include <jffs2/load_kernel.h>
 #include <linux/mtd/mtd.h>
 
 int mtd_probe_devices(void);
 
 void board_mtdparts_default(const char **mtdids, const char **mtdparts);
 
+/* compute the max size for the string associated to a dev type */
+#define MTD_NAME_SIZE(type) (sizeof(MTD_DEV_TYPE(type)) +  DM_MAX_SEQ_STR)
+
 #endif	/* _MTD_H_ */