mtd: spi-nor: provide default erase_sector implementation
Some spi-nor drivers perform sector erase by duplicating their
write_reg() command. Let's not require that the driver fill this out,
and provide a default instead.
Tested on m25p80.c and Medatek's MT8173 SPI NOR flash driver.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 16c9f55..a38ec01 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -38,6 +38,7 @@
#define CHIP_ERASE_2MB_READY_WAIT_JIFFIES (40UL * HZ)
#define SPI_NOR_MAX_ID_LEN 6
+#define SPI_NOR_MAX_ADDR_WIDTH 4
struct flash_info {
char *name;
@@ -313,6 +314,29 @@
}
/*
+ * Initiate the erasure of a single sector
+ */
+static int spi_nor_erase_sector(struct spi_nor *nor, u32 addr)
+{
+ u8 buf[SPI_NOR_MAX_ADDR_WIDTH];
+ int i;
+
+ if (nor->erase)
+ return nor->erase(nor, addr);
+
+ /*
+ * Default implementation, if driver doesn't have a specialized HW
+ * control
+ */
+ for (i = nor->addr_width - 1; i >= 0; i--) {
+ buf[i] = addr & 0xff;
+ addr >>= 8;
+ }
+
+ return nor->write_reg(nor, nor->erase_opcode, buf, nor->addr_width);
+}
+
+/*
* Erase an address range on the nor chip. The address range may extend
* one or more erase sectors. Return an error is there is a problem erasing.
*/
@@ -371,10 +395,9 @@
while (len) {
write_enable(nor);
- if (nor->erase(nor, addr)) {
- ret = -EIO;
+ ret = spi_nor_erase_sector(nor, addr);
+ if (ret)
goto erase_err;
- }
addr += mtd->erasesize;
len -= mtd->erasesize;
@@ -1138,7 +1161,7 @@
static int spi_nor_check(struct spi_nor *nor)
{
if (!nor->dev || !nor->read || !nor->write ||
- !nor->read_reg || !nor->write_reg || !nor->erase) {
+ !nor->read_reg || !nor->write_reg) {
pr_err("spi-nor: please fill all the necessary fields!\n");
return -EINVAL;
}
@@ -1340,6 +1363,12 @@
nor->addr_width = 3;
}
+ if (nor->addr_width > SPI_NOR_MAX_ADDR_WIDTH) {
+ dev_err(dev, "address width is too large: %u\n",
+ nor->addr_width);
+ return -EINVAL;
+ }
+
nor->read_dummy = spi_nor_read_dummy_cycles(nor);
dev_info(dev, "%s (%lld Kbytes)\n", info->name,
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index 955f268..7bed974 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -143,7 +143,8 @@
* @read: [DRIVER-SPECIFIC] read data from the SPI NOR
* @write: [DRIVER-SPECIFIC] write data to the SPI NOR
* @erase: [DRIVER-SPECIFIC] erase a sector of the SPI NOR
- * at the offset @offs
+ * at the offset @offs; if not provided by the driver,
+ * spi-nor will send the erase opcode via write_reg()
* @flash_lock: [FLASH-SPECIFIC] lock a region of the SPI NOR
* @flash_unlock: [FLASH-SPECIFIC] unlock a region of the SPI NOR
* @flash_is_locked: [FLASH-SPECIFIC] check if a region of the SPI NOR is