Commit b92c3aa6 authored by Andriy Gelman's avatar Andriy Gelman Committed by Benjamin Cabé
Browse files

drivers: flash: spi_nor: Set 4-byte addr mode via write instruction 0x17 



Some flash devices enable entering the 4-byte address mode
by setting BIT(7) in a special register via a write instruction 0x17.
The support for this method is indicated in BIT(3) of
Enter 4-Byte Addressing byte in 16th DWORD of the JEDEC Basic
Flash Parameter Table.

Infineon's S25FL512S is an example flash device with this feature.

Signed-off-by: default avatarAndriy Gelman <andriy.gelman@gmail.com>
parent 3b43cb31

drivers/flash/spi_nor.c

+19 −5
Original line number Diff line number Diff line
@@ -1139,13 +1139,26 @@ static int spi_nor_set_address_mode(const struct device *dev, 


	/* This currently only supports command 0xB7 (Enter 4-Byte

	 * Address Mode), with or without preceding WREN.

	 * Or when BIT(3) is set where the 4-byte address mode can be entered

	 * by setting BIT(7) in a register via a 0x17 write

	 * instruction. See JEDEC 216F 16th DWORD.

	 */

	if ((enter_4byte_addr & 0x03) == 0) {

	if ((enter_4byte_addr & 0x0b) == 0) {

		return -ENOTSUP;

	}



	acquire_device(dev);



	if ((enter_4byte_addr & 0x08) != 0) {

		/* Enter 4-byte address mode by setting BIT(7) in a register

		 * via a 0x17 write instruction.

		 */

		uint8_t sr = BIT(7);



		ret = spi_nor_access(dev, 0x17, NOR_ACCESS_WRITE, 0, &sr, sizeof(sr));

		goto done;

	}



	if ((enter_4byte_addr & 0x02) != 0) {

		/* Enter after WREN. */

		ret = spi_nor_cmd_write(dev, SPI_NOR_CMD_WREN);
@@ -1153,13 +1166,14 @@ static int spi_nor_set_address_mode(const struct device *dev, 


	if (ret == 0) {

		ret = spi_nor_cmd_write(dev, SPI_NOR_CMD_4BA);

	}



done:

	if (ret == 0) {

		struct spi_nor_data *data = dev->data;



		data->flag_access_32bit = true;

	}

	}



	release_device(dev);

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