The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.
To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().
Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Link: https://lore.kernel.org/linux-mtd/20231008200143.196369-11-u.kleine-koenig@pengutronix.de
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.
To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().
Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Link: https://lore.kernel.org/linux-mtd/20231008200143.196369-10-u.kleine-koenig@pengutronix.de
Now the rpcif_{en,dis}able_rpm() wrappers just take a pointer to a
device structure, there is no point in keeping them. Remove them, and
update the callers to call Runtime PM directly.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/d87aa5d7e4a39b18f7e2e0649fee0a45b45d371f.1669213027.git.geert+renesas@glider.be
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Most rpcif_*() API functions do not need access to any other fields in
the rpcif structure than the device pointer. Simplify dependencies by
passing the device pointer instead.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/0460fe82ba348cedec7a9a75a8eff762c50e817b.1669213027.git.geert+renesas@glider.be
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
The only thing that could theoretically fail in that function is
mtd_device_unregister(). However it's not supposed to fail and when
used correctly it doesn't. So wail loudly if it does anyhow.
This matches how other drivers (e.g. nand/raw/nandsim.c) use
mtd_device_unregister().
This is a preparation for making platform remove callbacks return void.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220603210758.148493-2-u.kleine-koenig@pengutronix.de
The AM65x HyperBus controller is only present on Texas Instruments AM65x
SoCs. Hence add a dependency on ARCH_K3, to prevent asking the user
about this driver when configuring a kernel without support for the
Texas Instruments Inc. K3 multicore SoC architecture.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/9fd6b975adba710158f28aa603cf87a6d189a418.1646655894.git.geert+renesas@glider.be
* mtdchar: Prevent unbounded allocation in MEMWRITE ioctl
* gen_probe: Use bitmap_zalloc() when applicable
* Introduce an expert mode for forensics and debugging purposes
* Clear out unregistered devices a bit more
* Provide unique name for nvmem device
* Remove unused header file <linux/mtd/latch-addr-flash.h>
* Fixed breaking list in __mtd_del_partition.
MTD device changes:
* sst25l, mchp48l640, mchp23k256, dataflash:
- Warn about failure to unregister mtd device
Raw NAND core changes:
* Export nand_read_page_hwecc_oob_first()
GPMC memory controller for OMAP2 NAND controller changes:
* GPMC:
- Add support for AM64 SoC and allow build on K3 platforms
- Use a compatible match table when checking for NAND controller
- Use platform_get_irq() to get the interrupt
Raw NAND controller changes:
* OMAP2 NAND controller:
- Document the missing 'rb-gpios' DT property
- Drop unused variable
- Fix force_8bit flag behaviour for DMA mode
- Move to exec_op interface
- Use platform_get_irq() to get the interrupt
* Renesas:
- Add new NAND controller driver with its bindings and MAINTAINERS entry
* Onenand:
- Remove redundant variable ooblen
* MPC5121:
- Remove unused variable in ads5121_select_chip()
* GPMI:
- Add ERR007117 protection for nfc_apply_timings
- Remove explicit default gpmi clock setting for i.MX6
- Use platform_get_irq_byname() to get the interrupt
- Remove unneeded variable
* Ingenic:
- JZ4740 needs 'oob_first' read page function
* Davinci:
- Rewrite function description
- Avoid duplicated page read
- Don't calculate ECC when reading page
SPI NOR core changes:
* Add Pratyush as SPI NOR co-maintainer.
* Flash parameters initialization was done in a spaghetti way. Clean
flash parameters initialization.
* Rework the flash_info flags and clarify where one should be used.
* Initialize all flash parameters based on JESD216 SFDP where possible.
Flash parameters and settings that are SFDP discoverable should not be
duplicated via flash_info flags at flash declaration.
* Remove debugfs entries that duplicate sysfs entries.
SPI NOR manufacturer driver changes:
* Use late_init() hook in various drivers to make it clear that those
flash parameters are either not declared in the JESD216 SFDP standard,
or the SFDP tables which define those flash parameters are not defined
by the flash.
* Fix mtd size for s3an flashes.
* Write 2 bytes when disabling Octal DTR mode: 1 byte long transactions are
not allowed in 8D-8D-8D mode.
Hyperbus changes:
* Couple of fixes in Renesas hyperbus rpc-if driver to avoid crash on
module remove and for missing check for error value in probe.
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Merge tag 'mtd/for-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux
Pull MTD updates from Miquel Raynal:
"MTD core changes:
- mtdchar: Prevent unbounded allocation in MEMWRITE ioctl
- gen_probe: Use bitmap_zalloc() when applicable
- Introduce an expert mode for forensics and debugging purposes
- Clear out unregistered devices a bit more
- Provide unique name for nvmem device
- Remove unused header file <linux/mtd/latch-addr-flash.h>
- Fixed breaking list in __mtd_del_partition.
MTD device changes:
- Warn about failure to unregister mtd device in sst25l, mchp48l640,
mchp23k256, and dataflash drivers.
Raw NAND core changes:
- Export nand_read_page_hwecc_oob_first()
GPMC memory controller for OMAP2 NAND controller changes:
- Add support for AM64 SoC and allow build on K3 platforms
- Use a compatible match table when checking for NAND controller
- Use platform_get_irq() to get the interrupt
Raw NAND controller changes:
- OMAP2 NAND controller:
- Document the missing 'rb-gpios' DT property
- Drop unused variable
- Fix force_8bit flag behaviour for DMA mode
- Move to exec_op interface
- Use platform_get_irq() to get the interrupt
- Renesas:
- Add new NAND controller driver with its bindings and MAINTAINERS entry
- Onenand:
- Remove redundant variable ooblen
- MPC5121:
- Remove unused variable in ads5121_select_chip()
- GPMI:
- Add ERR007117 protection for nfc_apply_timings
- Remove explicit default gpmi clock setting for i.MX6
- Use platform_get_irq_byname() to get the interrupt
- Remove unneeded variable
- Ingenic:
- JZ4740 needs 'oob_first' read page function
- Davinci:
- Rewrite function description
- Avoid duplicated page read
- Don't calculate ECC when reading page
SPI NOR core changes:
- Add Pratyush as SPI NOR co-maintainer.
- Flash parameters initialization was done in a spaghetti way. Clean
flash parameters initialization.
- Rework the flash_info flags and clarify where one should be used.
- Initialize all flash parameters based on JESD216 SFDP where
possible. Flash parameters and settings that are SFDP discoverable
should not be duplicated via flash_info flags at flash declaration.
- Remove debugfs entries that duplicate sysfs entries.
SPI NOR manufacturer driver changes:
- Use late_init() hook in various drivers to make it clear that those
flash parameters are either not declared in the JESD216 SFDP
standard, or the SFDP tables which define those flash parameters
are not defined by the flash.
- Fix mtd size for s3an flashes.
- Write 2 bytes when disabling Octal DTR mode: 1 byte long
transactions are not allowed in 8D-8D-8D mode.
Hyperbus changes:
- Couple of fixes in Renesas hyperbus rpc-if driver to avoid crash on
module remove and for missing check for error value in probe"
* tag 'mtd/for-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux: (71 commits)
mtd: spi-nor: Remove debugfs entries that duplicate sysfs entries
mtd: spi-nor: micron-st: write 2 bytes when disabling Octal DTR mode
mtd: spi-nor: spansion: write 2 bytes when disabling Octal DTR mode
mtd: spi-nor: core: use 2 data bytes for template ops
mtd: spi-nor: Constify part specific fixup hooks
mtd: spi-nor: core: Remove reference to spi-nor.c
mtd: rawnand: gpmi: Use platform_get_irq_byname() to get the interrupt
mtd: rawnand: omap_elm: Use platform_get_irq() to get the interrupt
mtd: rawnand: omap2: Select GPMC device driver for ARCH_K3
memory: omap-gpmc: Use a compatible match table when checking for NAND controller
memory: omap-gpmc: Add support for GPMC on AM64 SoC
dt-bindings: memory-controllers: ti,gpmc: Add compatible for AM64
memory: omap-gpmc: Use platform_get_irq() to get the interrupt
MAINTAINERS: Add an entry for Renesas NAND controller
mtd: rawnand: renesas: Add new NAND controller driver
dt-bindings: mtd: renesas: Describe Renesas R-Car Gen3 & RZ/N1 NAND controller
mtd: rawnand: gpmi: remove unneeded variable
mtd: rawnand: omap2: drop unused variable
mtd: rawnand: omap2: fix force_8bit flag behaviour for DMA mode
mtd: rawnand: omap2: Add compatible for AM64 SoC
...
The following KASAN BUG is observed when testing the rpc-if driver on
rcar-gen3:
root@rcar-gen3:~# modprobe -r rpc-if
[ 101.930146] ==================================================================
[ 101.937408] BUG: KASAN: slab-out-of-bounds in __lock_acquire+0x518/0x25d0
[ 101.944240] Read of size 8 at addr ffff0004c5be2750 by task modprobe/664
[ 101.950959]
[ 101.952466] CPU: 2 PID: 664 Comm: modprobe Not tainted 5.14.0-rc1-00342-g1a1464d7aa31 #1
[ 101.960578] Hardware name: Renesas H3ULCB board based on r8a77951 (DT)
[ 101.967120] Call trace:
[ 101.969580] dump_backtrace+0x0/0x2c0
[ 101.973275] show_stack+0x1c/0x30
[ 101.976616] dump_stack_lvl+0x9c/0xd8
[ 101.980301] print_address_description.constprop.0+0x74/0x2b8
[ 101.986071] kasan_report+0x1f4/0x26c
[ 101.989757] __asan_load8+0x98/0xd4
[ 101.993266] __lock_acquire+0x518/0x25d0
[ 101.997215] lock_acquire.part.0+0x18c/0x360
[ 102.001506] lock_acquire+0x74/0x90
[ 102.005013] _raw_spin_lock_irq+0x98/0x130
[ 102.009131] __pm_runtime_disable+0x30/0x210
[ 102.013427] rpcif_hb_remove+0x5c/0x70 [rpc_if]
[ 102.018001] platform_remove+0x40/0x80
[ 102.021771] __device_release_driver+0x234/0x350
[ 102.026412] driver_detach+0x158/0x20c
[ 102.030179] bus_remove_driver+0xa0/0x140
[ 102.034212] driver_unregister+0x48/0x80
[ 102.038153] platform_driver_unregister+0x18/0x24
[ 102.042879] rpcif_platform_driver_exit+0x1c/0x34 [rpc_if]
[ 102.048400] __arm64_sys_delete_module+0x210/0x310
[ 102.053212] invoke_syscall+0x60/0x190
[ 102.056986] el0_svc_common+0x12c/0x144
[ 102.060844] do_el0_svc+0x88/0xac
[ 102.064181] el0_svc+0x24/0x3c
[ 102.067257] el0t_64_sync_handler+0x1a8/0x1b0
[ 102.071634] el0t_64_sync+0x198/0x19c
[ 102.075315]
[ 102.076815] Allocated by task 628:
[ 102.080781]
[ 102.082280] Last potentially related work creation:
[ 102.087524]
[ 102.089022] The buggy address belongs to the object at ffff0004c5be2000
[ 102.089022] which belongs to the cache kmalloc-2k of size 2048
[ 102.101555] The buggy address is located 1872 bytes inside of
[ 102.101555] 2048-byte region [ffff0004c5be2000, ffff0004c5be2800)
[ 102.113486] The buggy address belongs to the page:
[ 102.118409]
[ 102.119908] Memory state around the buggy address:
[ 102.124711] ffff0004c5be2600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 102.131947] ffff0004c5be2680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 102.139181] >ffff0004c5be2700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 102.146412] ^
[ 102.152257] ffff0004c5be2780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 102.159491] ffff0004c5be2800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 102.166723] ==================================================================
The above bug is caused by use of the wrong pointer in the
rpcif_disable_rpm() call. Fix the bug by using the correct pointer.
Fixes: 5de15b610f ("mtd: hyperbus: add Renesas RPC-IF driver")
Signed-off-by: George G. Davis <davis.george@siemens.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Link: https://lore.kernel.org/r/20210716204935.25859-1-george_davis@mentor.com
SPI Multi I/O Bus Controller on RZ/G2L SoC is almost identical to
the RPC-IF interface found on R-Car Gen3 SoC's.
This patch adds a new compatible string for the RZ/G2L family so
that the timing values on RZ/G2L can be adjusted.
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20211025205631.21151-8-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
rpcif_sw_init() can fail so make sure we check the return value
of it and on error exit rpcif_hb_probe() callback with error code.
Fixes: 5de15b610f ("mtd: hyperbus: add Renesas RPC-IF driver")
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20211025205631.21151-5-prabhakar.mahadev-lad.rj@bp.renesas.com
commit 5de15b610f ("mtd: hyperbus: add Renesas RPC-IF driver") leads
to build failure[1] with COMPILE_TEST and RPCIF_HYPERBUS enabled. This
is because driver needs functions RENESAS_RPCIF which is only buildable
for CONFIG_ARCH_RENESAS.
Fix this by dropping COMPILE_TEST from RPCIF_HYPERBUS Kconfig entry.
This ensures driver can be built only when RENESAS_RPCIF is also
selected.
[1]:
rpc-if.c:(.text+0x20): undefined reference to `rpcif_disable_rpm' ld:
drivers/mtd/hyperbus/rpc-if.o: in function `rpcif_hb_prepare_read':
rpc-if.c:(.text+0xd6): undefined reference to `rpcif_prepare' ld:
drivers/mtd/hyperbus/rpc-if.o: in function `rpcif_hb_read16':
[...]
Fixes: 5de15b610f ("mtd: hyperbus: add Renesas RPC-IF driver") leads
Reported-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Add the HyperFLash driver for the Renesas RPC-IF. It's the "front end"
driver using the "back end" APIs in the main driver to talk to the real
hardware.
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Link: https://lore.kernel.org/r/78abb851-2beb-fe7d-87e5-ce58ee877d35@gmail.com
AM654 HyperBus controller provides MMIO interface to read data from
flash. So add DMA memcpy support for reading data over MMIO interface.
This provides 5x improvement in throughput and reduces CPU usage as
well.
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Reviewed-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20200924081214.16934-5-vigneshr@ti.com
Recent genpd changes for K3 platform ensure device is ON before driver
probe is called. Therefore, drop redundant pm_runtime_* calls from
driver to simplify the code.
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Link: https://lore.kernel.org/r/20200924081214.16934-4-vigneshr@ti.com
Setting up of direct mapping should be done with flash node's IO
address space and not with controller's IO region.
Fixes: b6fe8bc67d ("mtd: hyperbus: move direct mapping setup to AM654 HBMC driver")
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Link: https://lore.kernel.org/r/20200924081214.16934-3-vigneshr@ti.com
Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.
Deterministic algorithm:
For each file:
If not .svg:
For each line:
If doesn't contain `\bxmlns\b`:
For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`:
If both the HTTP and HTTPS versions
return 200 OK and serve the same content:
Replace HTTP with HTTPS.
Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
The Hyperbus core expects that HyperFlash is always directly mapped for
both read and write, but in reality this may not always be the case, e.g.
Renesas RPC-IF has read only direct mapping. Move the code setting up the
direct mapping from the Hyperbus core to thh TI AM554 HBMC driver.
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
In case the compatible "cypress,hyperflash" is not given
output a proper error message.
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
lib/devres.c, which implements devm_ioremap_resource(), is only built
when CONFIG_HAS_IOMEM is set/enabled, so MTD_HYPERBUS should depend
on HAS_IOMEM. Fixes a build error and a Kconfig warning (as seen on
UML builds):
WARNING: unmet direct dependencies detected for MTD_COMPLEX_MAPPINGS
Depends on [n]: MTD [=m] && HAS_IOMEM [=n]
Selected by [m]:
- MTD_HYPERBUS [=m] && MTD [=m]
ERROR: "devm_ioremap_resource" [drivers/mtd/hyperbus/hyperbus-core.ko] undefined!
Fixes: dcc7d3446a ("mtd: Add support for HyperBus memory devices")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: linux-mtd@lists.infradead.org
Acked-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
The hbmc-am654 driver is for the TI AM654, which is an ARM64 SoC, so
don't propose this driver on other architectures unless
build-testing.
Fixes: b07079f164 ("mtd: hyperbus: Add driver for TI's HyperBus memory controller")
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
On x86_64, when CONFIG_OF is not disabled:
WARNING: unmet direct dependencies detected for MUX_MMIO
Depends on [n]: MULTIPLEXER [=y] && (OF [=n] || COMPILE_TEST [=n])
Selected by [y]:
- HBMC_AM654 [=y] && MTD [=y] && MTD_HYPERBUS [=y]
due to
config HBMC_AM654
tristate "HyperBus controller driver for AM65x SoC"
select MULTIPLEXER
select MUX_MMIO
Fix this by making HBMC_AM654 imply MUX_MMIO instead of select so
that dependencies are taken care of. MUX_MMIO is optional for
functioning of driver.
Fixes: b07079f164 ("mtd: hyperbus: Add driver for TI's HyperBus memory controller")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Add driver for HyperBus memory controller on TI's AM654 SoC. Programming
IP is pretty simple and provides direct memory mapped access to
connected Flash devices.
Add basic support for the IP without DMA. Second chip-select is not
supported for now.
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Cypress' HyperBus is Low Signal Count, High Performance Double Data Rate
Bus interface between a host system master and one or more slave
interfaces. HyperBus is used to connect microprocessor, microcontroller,
or ASIC devices with random access NOR flash memory (called HyperFlash)
or self refresh DRAM (called HyperRAM).
Its a 8-bit data bus (DQ[7:0]) with Read-Write Data Strobe (RWDS)
signal and either Single-ended clock(3.0V parts) or Differential clock
(1.8V parts). It uses ChipSelect lines to select b/w multiple slaves.
At bus level, it follows a separate protocol described in HyperBus
specification[1].
HyperFlash follows CFI AMD/Fujitsu Extended Command Set (0x0002) similar
to that of existing parallel NORs. Since HyperBus is x8 DDR bus,
its equivalent to x16 parallel NOR flash with respect to bits per clock
cycle. But HyperBus operates at >166MHz frequencies.
HyperRAM provides direct random read/write access to flash memory
array.
But, HyperBus memory controllers seem to abstract implementation details
and expose a simple MMIO interface to access connected flash.
Add support for registering HyperFlash devices with MTD framework. MTD
maps framework along with CFI chip support framework are used to support
communicating with flash.
Framework is modelled along the lines of spi-nor framework. HyperBus
memory controller (HBMC) drivers calls hyperbus_register_device() to
register a single HyperFlash device. HyperFlash core parses MMIO access
information from DT, sets up the map_info struct, probes CFI flash and
registers it with MTD framework.
Some HBMC masters need calibration/training sequence[3] to be carried
out, in order for DLL inside the controller to lock, by reading a known
string/pattern. This is done by repeatedly reading CFI Query
Identification String. Calibration needs to be done before trying to detect
flash as part of CFI flash probe.
HyperRAM is not supported at the moment.
HyperBus specification can be found at[1]
HyperFlash datasheet can be found at[2]
[1] https://www.cypress.com/file/213356/download
[2] https://www.cypress.com/file/213346/download
[3] http://www.ti.com/lit/ug/spruid7b/spruid7b.pdf
Table 12-5741. HyperFlash Access Sequence
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
