Merge tag 'mtd/for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux

[linux-block.git] / drivers / mtd / spi-nor / spi-nor.c

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index e3a28c0f22cb80b81cc655a60e28f0994c17b392..03cc788511d59e22935f2b03762191e24e14b663 100644 (file)
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -1636,6 +1636,95 @@ static int sr2_bit7_quad_enable(struct spi_nor *nor)
        return 0;
 }
 
+/**
+ * spi_nor_clear_sr_bp() - clear the Status Register Block Protection bits.
+ * @nor:        pointer to a 'struct spi_nor'
+ *
+ * Read-modify-write function that clears the Block Protection bits from the
+ * Status Register without affecting other bits.
+ *
+ * Return: 0 on success, -errno otherwise.
+ */
+static int spi_nor_clear_sr_bp(struct spi_nor *nor)
+{
+       int ret;
+       u8 mask = SR_BP2 | SR_BP1 | SR_BP0;
+
+       ret = read_sr(nor);
+       if (ret < 0) {
+               dev_err(nor->dev, "error while reading status register\n");
+               return ret;
+       }
+
+       write_enable(nor);
+
+       ret = write_sr(nor, ret & ~mask);
+       if (ret) {
+               dev_err(nor->dev, "write to status register failed\n");
+               return ret;
+       }
+
+       ret = spi_nor_wait_till_ready(nor);
+       if (ret)
+               dev_err(nor->dev, "timeout while writing status register\n");
+       return ret;
+}
+
+/**
+ * spi_nor_spansion_clear_sr_bp() - clear the Status Register Block Protection
+ * bits on spansion flashes.
+ * @nor:        pointer to a 'struct spi_nor'
+ *
+ * Read-modify-write function that clears the Block Protection bits from the
+ * Status Register without affecting other bits. The function is tightly
+ * coupled with the spansion_quad_enable() function. Both assume that the Write
+ * Register with 16 bits, together with the Read Configuration Register (35h)
+ * instructions are supported.
+ *
+ * Return: 0 on success, -errno otherwise.
+ */
+static int spi_nor_spansion_clear_sr_bp(struct spi_nor *nor)
+{
+       int ret;
+       u8 mask = SR_BP2 | SR_BP1 | SR_BP0;
+       u8 sr_cr[2] = {0};
+
+       /* Check current Quad Enable bit value. */
+       ret = read_cr(nor);
+       if (ret < 0) {
+               dev_err(nor->dev,
+                       "error while reading configuration register\n");
+               return ret;
+       }
+
+       /*
+        * When the configuration register Quad Enable bit is one, only the
+        * Write Status (01h) command with two data bytes may be used.
+        */
+       if (ret & CR_QUAD_EN_SPAN) {
+               sr_cr[1] = ret;
+
+               ret = read_sr(nor);
+               if (ret < 0) {
+                       dev_err(nor->dev,
+                               "error while reading status register\n");
+                       return ret;
+               }
+               sr_cr[0] = ret & ~mask;
+
+               ret = write_sr_cr(nor, sr_cr);
+               if (ret)
+                       dev_err(nor->dev, "16-bit write register failed\n");
+               return ret;
+       }
+
+       /*
+        * If the Quad Enable bit is zero, use the Write Status (01h) command
+        * with one data byte.
+        */
+       return spi_nor_clear_sr_bp(nor);
+}
+
 /* Used when the "_ext_id" is two bytes at most */
 #define INFO(_jedec_id, _ext_id, _sector_size, _n_sectors, _flags)     \
                .id = {                                                 \
@@ -3691,6 +3780,8 @@ static int spi_nor_init_params(struct spi_nor *nor,
                default:
                        /* Kept only for backward compatibility purpose. */
                        params->quad_enable = spansion_quad_enable;
+                       if (nor->clear_sr_bp)
+                               nor->clear_sr_bp = spi_nor_spansion_clear_sr_bp;
                        break;
                }
 
@@ -3943,17 +4034,13 @@ static int spi_nor_init(struct spi_nor *nor)
 {
        int err;
 
-       /*
-        * Atmel, SST, Intel/Numonyx, and others serial NOR tend to power up
-        * with the software protection bits set
-        */
-       if (JEDEC_MFR(nor->info) == SNOR_MFR_ATMEL ||
-           JEDEC_MFR(nor->info) == SNOR_MFR_INTEL ||
-           JEDEC_MFR(nor->info) == SNOR_MFR_SST ||
-           nor->info->flags & SPI_NOR_HAS_LOCK) {
-               write_enable(nor);
-               write_sr(nor, 0);
-               spi_nor_wait_till_ready(nor);
+       if (nor->clear_sr_bp) {
+               err = nor->clear_sr_bp(nor);
+               if (err) {
+                       dev_err(nor->dev,
+                               "fail to clear block protection bits\n");
+                       return err;
+               }
        }
 
        if (nor->quad_enable) {
@@ -4078,6 +4165,16 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
        if (info->flags & SPI_S3AN)
                nor->flags |=  SNOR_F_READY_XSR_RDY;
 
+       /*
+        * Atmel, SST, Intel/Numonyx, and others serial NOR tend to power up
+        * with the software protection bits set.
+        */
+       if (JEDEC_MFR(nor->info) == SNOR_MFR_ATMEL ||
+           JEDEC_MFR(nor->info) == SNOR_MFR_INTEL ||
+           JEDEC_MFR(nor->info) == SNOR_MFR_SST ||
+           nor->info->flags & SPI_NOR_HAS_LOCK)
+               nor->clear_sr_bp = spi_nor_clear_sr_bp;
+
        /* Parse the Serial Flash Discoverable Parameters table. */
        ret = spi_nor_init_params(nor, &params);
        if (ret)