[PATCH v3 0/3] Merge m25p80 into spi-nor

[Vignesh Raghavendra <vigneshr@ti.com>]

This is repost of patch 6 and 7 split from from Boris Brezillon's X-X-X
mode support series[1]

Background from cover letter for RFC[1]:
m25p80 is just a simple SPI NOR controller driver (a wrapper around the
SPI mem API). Not only it shouldn't be named after a specific SPI NOR
chip, but it also doesn't deserve a specific driver IMO, especially if
the end goal is to get rid of SPI NOR controller drivers found in
drivers/mtd/spi-nor/ and replace them by SPI mem drivers (which would
be placed in drivers/spi/). With this solution, we declare the SPI NOR
driver as a spi_mem_driver, just like the SPI NAND layer is declared as
a spi_mem driver (patch 1/2).
This solution also allows us to check at a fined-grain level (thanks to
the spi_mem_supports_op() function) which operations are supported and
which ones are not, while the original m25p80 logic was basing this
decision on the SPI_{RX,TX}_{DUAL,QUAD,OCTO} flags only (patch 2/2).

[1] https://patchwork.ozlabs.org/cover/982926/

Tested on TI' DRA7xx EVM with TI QSPI controller (a spi-mem driver) with
DMA (s25fl256) flash. I don't see any performance regression due to
bounce buffer copy introduced by this series
Also tested with cadence-quadspi (a spi-nor driver) driver

Boris Brezillon (2):
  mtd: spi-nor: Move m25p80 code in spi-nor.c
  mtd: spi-nor: Rework hwcaps selection for the spi-mem case

Vignesh Raghavendra (1):
  mtd: spi-nor: always use bounce buffer for register read/writes

 drivers/mtd/devices/Kconfig   |  18 -
 drivers/mtd/devices/Makefile  |   1 -
 drivers/mtd/devices/m25p80.c  | 347 ---------------
 drivers/mtd/spi-nor/Kconfig   |   2 +
 drivers/mtd/spi-nor/spi-nor.c | 802 +++++++++++++++++++++++++++++++---
 include/linux/mtd/spi-nor.h   |  24 +-
 6 files changed, 769 insertions(+), 425 deletions(-)
 delete mode 100644 drivers/mtd/devices/m25p80.c

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2.22.0