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>
Jean Delvare