mtd: spi-nor: Fix whole chip erasing for stacked chips.

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Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=2f5ad7f0f3e16772bafa692ad42b5af4dea292f6
Commit:     2f5ad7f0f3e16772bafa692ad42b5af4dea292f6
Parent:     ca1fa1a8a6dae3e10c73bc5f1da728e662ee9d8b
Author:     mar.krzeminski <mar.krzeminski at gmail.com>
AuthorDate: Fri Jan 6 18:19:00 2017 +0100
Committer:  Cyrille Pitchen <cyrille.pitchen at atmel.com>
CommitDate: Wed Mar 22 21:52:53 2017 +0100

    mtd: spi-nor: Fix whole chip erasing for stacked chips.
    
    Currently it is possible to disable chip erase for spi-nor driver.
    Some modern stacked (multi die) flash chips do not support chip
    erase opcode at all but spi-nor framework needs to cope with them too.
    This commit extends existing functionality to allow disable
    chip erase for a single flash chip.
    
    Signed-off-by: Marcin Krzeminski <mar.krzeminski at gmail.com>
    Signed-off-by: Cyrille Pitchen <cyrille.pitchen at atmel.com>
---
 drivers/mtd/spi-nor/spi-nor.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 561e46d..c29a351 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -85,6 +85,7 @@ struct flash_info {
 					 * Use dedicated 4byte address op codes
 					 * to support memory size above 128Mib.
 					 */
+#define NO_CHIP_ERASE		BIT(12) /* Chip does not support chip erase */
 };
 
 #define JEDEC_MFR(info)	((info)->id[0])
@@ -1631,6 +1632,8 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode)
 		nor->flags |= SNOR_F_USE_FSR;
 	if (info->flags & SPI_NOR_HAS_TB)
 		nor->flags |= SNOR_F_HAS_SR_TB;
+	if (info->flags & NO_CHIP_ERASE)
+		nor->flags |= SNOR_F_NO_OP_CHIP_ERASE;
 
 #ifdef CONFIG_MTD_SPI_NOR_USE_4K_SECTORS
 	/* prefer "small sector" erase if possible */