mtd: spi-nor: atmel: fix unlock_all() for AT25FS010/040
These flashes have some weird BP bits mapping which aren't supported in
the current locking code. Just add a simple unlock op to unprotect the
entire flash array which is needed for legacy behavior.
Fixes: 3e0930f109e7 ("mtd: spi-nor: Rework the disabling of block write protection")
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20201203162959.29589-7-michael@walle.cc
diff --git a/drivers/mtd/spi-nor/atmel.c b/drivers/mtd/spi-nor/atmel.c
index 49d392c..deacf87 100644
--- a/drivers/mtd/spi-nor/atmel.c
+++ b/drivers/mtd/spi-nor/atmel.c
@@ -8,10 +8,59 @@
#include "core.h"
+/*
+ * The Atmel AT25FS010/AT25FS040 parts have some weird configuration for the
+ * block protection bits. We don't support them. But legacy behavior in linux
+ * is to unlock the whole flash array on startup. Therefore, we have to support
+ * exactly this operation.
+ */
+static int atmel_at25fs_lock(struct spi_nor *nor, loff_t ofs, uint64_t len)
+{
+ return -EOPNOTSUPP;
+}
+
+static int atmel_at25fs_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len)
+{
+ int ret;
+
+ /* We only support unlocking the whole flash array */
+ if (ofs || len != nor->params->size)
+ return -EINVAL;
+
+ /* Write 0x00 to the status register to disable write protection */
+ ret = spi_nor_write_sr_and_check(nor, 0);
+ if (ret)
+ dev_dbg(nor->dev, "unable to clear BP bits, WP# asserted?\n");
+
+ return ret;
+}
+
+static int atmel_at25fs_is_locked(struct spi_nor *nor, loff_t ofs, uint64_t len)
+{
+ return -EOPNOTSUPP;
+}
+
+static const struct spi_nor_locking_ops atmel_at25fs_locking_ops = {
+ .lock = atmel_at25fs_lock,
+ .unlock = atmel_at25fs_unlock,
+ .is_locked = atmel_at25fs_is_locked,
+};
+
+static void atmel_at25fs_default_init(struct spi_nor *nor)
+{
+ nor->params->locking_ops = &atmel_at25fs_locking_ops;
+}
+
+static const struct spi_nor_fixups atmel_at25fs_fixups = {
+ .default_init = atmel_at25fs_default_init,
+};
+
static const struct flash_info atmel_parts[] = {
/* Atmel -- some are (confusingly) marketed as "DataFlash" */
- { "at25fs010", INFO(0x1f6601, 0, 32 * 1024, 4, SECT_4K | SPI_NOR_HAS_LOCK) },
- { "at25fs040", INFO(0x1f6604, 0, 64 * 1024, 8, SECT_4K | SPI_NOR_HAS_LOCK) },
+ { "at25fs010", INFO(0x1f6601, 0, 32 * 1024, 4, SECT_4K | SPI_NOR_HAS_LOCK)
+ .fixups = &atmel_at25fs_fixups },
+ { "at25fs040", INFO(0x1f6604, 0, 64 * 1024, 8, SECT_4K | SPI_NOR_HAS_LOCK)
+ .fixups = &atmel_at25fs_fixups },
{ "at25df041a", INFO(0x1f4401, 0, 64 * 1024, 8, SECT_4K | SPI_NOR_HAS_LOCK) },
{ "at25df321", INFO(0x1f4700, 0, 64 * 1024, 64, SECT_4K | SPI_NOR_HAS_LOCK) },