Commit Graph

9 Commits

Author SHA1 Message Date
Geert Uytterhoeven 0bc448b49e mtd: maps: physmap: Add minimal Runtime PM support
Add minimal runtime PM support (enable on probe, disable on remove), to
ensure proper operation with a parent device that uses runtime PM.

This is needed on systems where the FLASH is connected to a bus
controller that is contained in a PM domain and/or has a gateable
functional clock.  In such cases, before accessing any device connected
to the external bus, the PM domain must be powered up, and/or the
functional clock must be enabled, which is typically handled through
runtime PM by the bus controller driver.

An example of this is the Renesas APE6-EVM development board, which has
an Ethernet controller and a CFI FLASH connected to the Bus State
Controller (BSC) of an R-Mobile APE6 SoC.
As long as the Ethernet driver, which had Runtime PM support since
commit 3a611e26e9 ("net/smsc911x: Add minimal runtime PM
support"), keeps the BSC powered, accessing the FLASH works.
When the ethernet node in r8a73a4-ape6evm.dts is disabled, the BSC is
never powered up, and the kernel crashes when trying to access the
FLASH:

    Unhandled fault: imprecise external abort (0x1406) at 0x00000000
    pgd = (ptrval)
    [00000000] *pgd=7fef2835
    Internal error: : 1406 [#1] SMP ARM
    CPU: 0 PID: 122 Comm: hd Tainted: G        W         5.5.0-rc1-ape6evm-00814-g38ca966db25b9dbd-dirty #136
    Hardware name: Generic R8A73A4 (Flattened Device Tree)
    PC is at chip_ready+0x12c/0x380
    LR is at chip_ready+0x10c/0x380

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
2020-01-27 16:55:31 +01:00
Linus Walleij 2aba2f2a70 mtd: physmap_of: add a hook for Intel IXP4xx flash probing
In order to support device tree probing of IXP4xx NOR flash
chips, a certain big-endian or mixed-endian memory access
pattern need to be used.

I have opted to use the pattern set by previous plug-ins
to physmap for Gemini and Versatile, just override some
functions and reuse most of the physmap core code as it
is to minimize maintenance.

Parts of drivers/mtd/ixp4xx.c are copied into this file.

After we have IXP4xx converted fully to device tree, the
drivers/mtd/ixp4xx.c file will be deleted and this will
be the only access pattern to the IXP4xx flash.

I did not keep the quirk in the flash write function
after probe, where the old code for a while checks for
access to odd addresses, fails and assigns a "faster"
write function once it has convinced probe to only use
2-byte accesses. As we mandate that this device should
be using bank-width = <2> this should not be a problem
unless misconfigured.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
2019-10-29 14:24:53 +01:00
Chris Packham 64d14c6fe0 mtd: maps: physmap: Store gpio_values correctly
When the gpio-addr-flash.c driver was merged with physmap-core.c the
code to store the current gpio_values was lost. This meant that once a
gpio was asserted it was never de-asserted. Fix this by storing the
current offset in gpio_values like the old driver used to.

Fixes: commit ba32ce95cb ("mtd: maps: Merge gpio-addr-flash.c into physmap-core.c")
Cc: <stable@vger.kernel.org>
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2019-05-06 21:46:45 +02:00
Linus Walleij b3dd93030c mtd: maps: physmap: Leave assigned complex mappings
SoC-specific drivers might provide their own map->xxx()
implementations, and calling simple_map_init() unconditionally will
override those implementations.

Make sure map->read is NULL before calling simple_map_init().

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
2018-12-06 16:57:13 +01:00
Ricardo Ribalda Delgado 99f732b3a8 mtd: maps: physmap: Invert logic on if/else branch
It is preferred to have the positive statement on an if/else. While we
are at it we replace the way we access rom_probe_types.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
2018-11-06 23:33:06 +01:00
Boris Brezillon ba32ce95cb mtd: maps: Merge gpio-addr-flash.c into physmap-core.c
Controlling some MSB address lines using GPIOs is just a small
deviation from the generic physmap logic, and merging those two drivers
allows us to share most of the probe logic, which is a good thing.

Also, the gpio-addr-flash driver is unused since the removal of
the blackfin arch in v4.17, so we can safely remove the old driver
without risking breaking existing boards.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Tested-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
2018-11-05 22:24:43 +01:00
Boris Brezillon 6ca15cfa07 mtd: maps: Rename physmap_of_{versatile, gemini} into physmap-{versatile, gemini}
Now that the physmap_of driver is gone, the gemini and versative
extensions are part of the physmap driver. Rename the source files and
the config option to reflect this.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
2018-11-05 22:24:29 +01:00
Boris Brezillon 642b1e8dbe mtd: maps: Merge physmap_of.c into physmap-core.c
There's no real reason to have two separate driver for the DT and pdata
case. Just do what we do everywhere else and handle DT and pdata
parsing in the same driver.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
2018-11-05 22:24:24 +01:00
Boris Brezillon 0c3def9b58 mtd: maps: Prepare merging of physmap and physmap_of
We want to merge the physmap and physmap_of driver, but before we can
do that we must prepare things to create physmap.o out of several .c
files. Rename physmap.c into physmap-core.c and add a new Makefile
rule to create physmap.o (right now it only contains physmap-core.o).

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
2018-11-05 22:24:20 +01:00