sf: Support querying write-protect
This feature was dropped from U-Boot some time ago:
f12f96cfaf5 (sf: Drop spl_flash_get_sw_write_prot")
However, we do need a way to see if a flash device is write-protected,
since if it is, it may not be possible to write to do (i.e. failing to
write is expected).
I am not sure of the correct layer to implement this, so this patch is a
stab at it. If spi-flash makes sense then I will add to the 'sf' also.
Re the points mentioned in the removal commit:
1) This kind of requirement can be achieved using existing
flash operations and flash locking API calls instead of
making a separate flash API.
Which uclass is this?
2) Technically there is no real hardware user for this API to
use in the source tree.
I do want coral (at least) to support this.
3) Having a flash operations API for simple register read bits
also make difficult to extend the flash operations.
This new patch only mentions write-protect being on or off, rather than
the actual mechanism.
4) Instead of touching generic code, it is possible to have
this functionality inside spinor operations in the form of
flash hooks or fixups for associated flash chips.
That sounds to me like what drivers are for. But we still need some sort
of API for it to be accessible.
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/mtd/spi/sf-uclass.c b/drivers/mtd/spi/sf-uclass.c
index fd1bec8..cfce00e 100644
--- a/drivers/mtd/spi/sf-uclass.c
+++ b/drivers/mtd/spi/sf-uclass.c
@@ -31,6 +31,15 @@
return log_ret(sf_get_ops(dev)->erase(dev, offset, len));
}
+int spl_flash_get_sw_write_prot(struct udevice *dev)
+{
+ struct dm_spi_flash_ops *ops = sf_get_ops(dev);
+
+ if (!ops->get_sw_write_prot)
+ return -ENOSYS;
+ return log_ret(ops->get_sw_write_prot(dev));
+}
+
/*
* TODO(sjg@chromium.org): This is an old-style function. We should remove
* it when all SPI flash drivers use dm
diff --git a/drivers/mtd/spi/sf_internal.h b/drivers/mtd/spi/sf_internal.h
index 9ceff0e..786301b 100644
--- a/drivers/mtd/spi/sf_internal.h
+++ b/drivers/mtd/spi/sf_internal.h
@@ -75,6 +75,10 @@
#define JEDEC_MFR(info) ((info)->id[0])
#define JEDEC_ID(info) (((info)->id[1]) << 8 | ((info)->id[2]))
+/* Get software write-protect value (BP bits) */
+int spi_flash_cmd_get_sw_write_prot(struct spi_flash *flash);
+
+
#if CONFIG_IS_ENABLED(SPI_FLASH_MTD)
int spi_flash_mtd_register(struct spi_flash *flash);
void spi_flash_mtd_unregister(void);
diff --git a/drivers/mtd/spi/sf_probe.c b/drivers/mtd/spi/sf_probe.c
index 6c87434..3befbe9 100644
--- a/drivers/mtd/spi/sf_probe.c
+++ b/drivers/mtd/spi/sf_probe.c
@@ -130,6 +130,13 @@
return mtd->_erase(mtd, &instr);
}
+static int spi_flash_std_get_sw_write_prot(struct udevice *dev)
+{
+ struct spi_flash *flash = dev_get_uclass_priv(dev);
+
+ return spi_flash_cmd_get_sw_write_prot(flash);
+}
+
int spi_flash_std_probe(struct udevice *dev)
{
struct spi_slave *slave = dev_get_parent_priv(dev);
@@ -153,6 +160,7 @@
.read = spi_flash_std_read,
.write = spi_flash_std_write,
.erase = spi_flash_std_erase,
+ .get_sw_write_prot = spi_flash_std_get_sw_write_prot,
};
static const struct udevice_id spi_flash_std_ids[] = {
diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c
index e0efebc..a662553 100644
--- a/drivers/mtd/spi/spi-nor-core.c
+++ b/drivers/mtd/spi/spi-nor-core.c
@@ -2647,3 +2647,14 @@
return 0;
}
+
+/* U-Boot specific functions, need to extend MTD to support these */
+int spi_flash_cmd_get_sw_write_prot(struct spi_nor *nor)
+{
+ int sr = read_sr(nor);
+
+ if (sr < 0)
+ return sr;
+
+ return (sr >> 2) & 7;
+}
diff --git a/drivers/mtd/spi/spi-nor-tiny.c b/drivers/mtd/spi/spi-nor-tiny.c
index 07c8c7b..1d5861d 100644
--- a/drivers/mtd/spi/spi-nor-tiny.c
+++ b/drivers/mtd/spi/spi-nor-tiny.c
@@ -809,3 +809,9 @@
return 0;
}
+
+/* U-Boot specific functions, need to extend MTD to support these */
+int spi_flash_cmd_get_sw_write_prot(struct spi_nor *nor)
+{
+ return -ENOTSUPP;
+}