The reg_stride field represents the address stride in bytes between
consecutive registers. The Linux kernel regmap framework validates
register accesses using IS_ALIGNED(reg, map->reg_stride) as an address
alignment check (drivers/base/regmap/regmap.c). The Linux kernel syscon
driver (drivers/mfd/syscon.c) sets reg_stride directly to reg_io_width:
syscon_config.reg_stride = reg_io_width;
The current OpenSBI code incorrectly multiplies reg_io_width by 8,
converting a byte value to bits. Fix this by using reg_io_width directly
as the stride value, consistent with the Linux kernel.
Fixes: f21d8f7d59 ("lib: utils/regmap: Add simple FDT based syscon regmap driver")
Signed-off-by: David E. Garcia Porras <david.garcia@aheadcomputing.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20260403202903.3407945-1-david.garcia@aheadcomputing.com
Signed-off-by: Anup Patel <anup@brainfault.org>
The regmap driver subsystem does not need any extra data, so it can use
`struct fdt_driver` directly. It always initializes the driver for a
specific DT node.
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
This allows the compiler to generate significantly better code, because
it does not have to maintain either the loop counter or loop limit. Plus
there are half as many symbols to relocate. This also simplifies passing
carray arrays to helper functions.
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Since the FDT is not modified during driver initialization, node offsets
are just as suitable as phandles for use as identifiers: they are stable
and unique. With this change, it is no longer necessary to pass the
phandle to the driver init functions, so these init functions now use
the same prototype as other kinds of drivers.
This matches what is already done for I2C adapters.
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
The syscon region used by OpenSBI should be marked as a shared
read-write region between M-mode and SU-mode.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com>
Let us add a simple FDT based system regmap driver which follows the
device tree bindings already defined in the Linux kernel.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Xiang W <wxjstz@126.com>
We add a simple FDT based regmap framework which is built on top of
generic regmap library. The phandle of FDT regmap DT node is treated
as unique regmap ID. The FDT based regmap drivers will be probed
on-demand from fdt_regmap_get_by_phandle() and fdt_regmap_get()
called by the regmap client drivers.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Xiang W <wxjstz@126.com>
We add generic regmap access library which is independent of
hardware description format (FDT or ACPI). The OpenSBI platform
support or regmap drivers can register regmap instances which
can be discovered by different regmap clients based on the
unique ID of regmap instances.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Xiang W <wxjstz@126.com>
David E. Garcia Porras