sf: Add a method to obtain the block-protect setting

It is useful to obtain the block-protect setting of the SPI flash, so we
know whether it is fully open or (perhaps partially) write-protected. Add
a method for this. Update the sandbox driver to process this operation and
add a test.

Signed-off-by: Simon Glass <sjg@chromium.org>

5 files changed, 42 insertions, 0 deletions

diff --git a/drivers/mtd/spi/sandbox.c b/drivers/mtd/spi/sandbox.c
index 7fef754c634..7b9891cb981 100644
--- a/drivers/mtd/spi/sandbox.c
+++ b/drivers/mtd/spi/sandbox.c
@@ -57,6 +57,8 @@ static const char *sandbox_sf_state_name(enum sandbox_sf_state state)
 /* Bits for the status register */
 #define STAT_WIP	(1 << 0)
 #define STAT_WEL	(1 << 1)
+#define STAT_BP_SHIFT	2
+#define STAT_BP_MASK	(7 << STAT_BP_SHIFT)
 
 /* Assume all SPI flashes have 3 byte addresses since they do atm */
 #define SF_ADDR_LEN	3
@@ -102,6 +104,14 @@ struct sandbox_spi_flash_plat_data {
 	int cs;
 };
 
+void sandbox_sf_set_block_protect(struct udevice *dev, int bp_mask)
+{
+	struct sandbox_spi_flash *sbsf = dev_get_priv(dev);
+
+	sbsf->status &= ~STAT_BP_MASK;
+	sbsf->status |= bp_mask << STAT_BP_SHIFT;
+}
+
 /**
  * This is a very strange probe function. If it has platform data (which may
  * have come from the device tree) then this function gets the filename and
diff --git a/drivers/mtd/spi/sf-uclass.c b/drivers/mtd/spi/sf-uclass.c
index 662525f016f..719a2fd23ae 100644
--- a/drivers/mtd/spi/sf-uclass.c
+++ b/drivers/mtd/spi/sf-uclass.c
@@ -28,6 +28,15 @@ int spi_flash_erase_dm(struct udevice *dev, u32 offset, size_t len)
 	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 26f5c7c995e..46a50444175 100644
--- a/drivers/mtd/spi/sf_internal.h
+++ b/drivers/mtd/spi/sf_internal.h
@@ -170,6 +170,9 @@ int spi_flash_cmd_write(struct spi_slave *spi, const u8 *cmd, size_t cmd_len,
 /* Flash erase(sectors) operation, support all possible erase commands */
 int spi_flash_cmd_erase_ops(struct spi_flash *flash, u32 offset, size_t len);
 
+/* Get software write-protect value (BP bits) */
+int spi_flash_cmd_get_sw_write_prot(struct spi_flash *flash);
+
 /* Lock stmicro spi flash region */
 int stm_lock(struct spi_flash *flash, u32 ofs, size_t len);
 
diff --git a/drivers/mtd/spi/sf_probe.c b/drivers/mtd/spi/sf_probe.c
index 94fde2ae7a3..5a2e932de8f 100644
--- a/drivers/mtd/spi/sf_probe.c
+++ b/drivers/mtd/spi/sf_probe.c
@@ -124,6 +124,13 @@ static int spi_flash_std_erase(struct udevice *dev, u32 offset, size_t len)
 	return spi_flash_cmd_erase_ops(flash, offset, len);
 }
 
+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);
+}
+
 static int spi_flash_std_probe(struct udevice *dev)
 {
 	struct spi_slave *slave = dev_get_parent_priv(dev);
@@ -141,6 +148,7 @@ static const struct dm_spi_flash_ops spi_flash_std_ops = {
 	.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_flash.c b/drivers/mtd/spi/spi_flash.c
index a87bacd4ac7..0c2392f28a4 100644
--- a/drivers/mtd/spi/spi_flash.c
+++ b/drivers/mtd/spi/spi_flash.c
@@ -110,6 +110,18 @@ static int write_cr(struct spi_flash *flash, u8 wc)
 }
 #endif
 
+int spi_flash_cmd_get_sw_write_prot(struct spi_flash *flash)
+{
+	u8 status;
+	int ret;
+
+	ret = read_sr(flash, &status);
+	if (ret)
+		return ret;
+
+	return (status >> 2) & 7;
+}
+
 #ifdef CONFIG_SPI_FLASH_BAR
 /*
  * This "clean_bar" is necessary in a situation when one was accessing