As we already added the quirk for lacking mtime register to MTIMER
driver, add T-Head C9xx CLINT compatible to it and wire the quirk.
Signed-off-by: Icenowy Zheng <uwu@icenowy.me>
Reviewed-by: Anup Patel <anup@brainfault.org>
T-Head developers surely have a different understanding of time CSR and
CLINT's mtime register with SiFive ones, that they did not implement
the mtime register at all -- as shown in openC906 source code, their
time CSR value is just exposed at the top of their processor IP block
and expects an external continous counter, which makes it not
overrideable, and thus mtime register is not implemented, even not for
reading. However, if CLINTEE is not enabled in T-Head's MXSTATUS
extended CSR, these systems still rely on the mtimecmp registers to
generate timer interrupts. This makes it necessary to implement T-Head
C9xx CLINT support in OpenSBI MTIMER driver, which skips implementing
reading mtime register and falls back to default code that reads time
CSR.
Add a quirk into MTIMER driver, which represents a mtime register is
lacking and time CSR value should be used instead.
Signed-off-by: Icenowy Zheng <uwu@icenowy.me>
Reviewed-by: Anup Patel <anup@brainfault.org>
The allwinner,sun20i-d1-clint compatible string is not documented in any
official binding, so it should not be used by drivers.
The MSWI in the D1 CLINT is compatible with the ACLINT specification, so
it can take advantage of generic driver support. However, that is only
possible if the MSWI and MTIMER are split into separate DT nodes. This
means the final binding for this device is likely to be incompatible
with what is implemented here.
Remove this compatible string from the driver to prevent it from
appearing in a stable version and causing future issues.
Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Anup Patel <anup@brainfault.org>
The CLINT in the Allwinner D1 SoC apparently does not support 64-bit
MMIO access. A property was added to support this quirk (and that
property was copied to the ACLINT MTIMER code). However, since this
difference in behavior makes the D1 CLINT incompatible with the SiFive
CLINT's programming interface, a better solution is to use a separate
compatible string.
Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Anup Patel <anup@brainfault.org>
Match data stores hardware attributes which do not change at runtime, so
it does not need to be mutable. Make it const.
Reviewed-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Samuel Holland <samuel@sholland.org>
Generic mdelay() and udelay() functions can be provided by the
sbi_timer framework if timer frequency is available in the timer
instance provided by the platform support or timer driver.
This patch adds timer frequency (timer_freq) member in the
struct sbi_timer_device for above purpose.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Xiang W <wxjstz@126.com>
We simplify MTIMER synchronization as follows:
1) Detect MTIMER devices with unique (or non-shared) MTIME
register at boot-time
2) Select first MTIMER device with no associated HART as our
reference MTIMER device
3) Only synchronize MTIMER devices with unique (or non-shared)
MTIME register using reference MTIMER device
4) Directly update the MTIME register at time of synchronization
because MTIME is a read/write register.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
We can have ACLINT MTIMER devices which only support 32-bit MMIO
accesses on RV64 system so this patch adds a boolean DT property
"mtimer,no-64bit-mmio" to detect this from MTIMER DT node.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
The fdt_parse_aclint_node() is used to parse DT node for SiFive
CLINT, ACLINT MTIMER, and ACLINT MSWI devices.
The ACLINT MTIMER has undergone following changes:
1) MTIMER DT node now requires separate addresses in for MTIME
register and MTIMECMPx registers in the reg DT property.
2) MTIMER DT node might have no interrupts-extended DT property
when the MTIMER device has no associated HARTs (i.e. the
MTIMER device has no MTIMECMPx registers)
This patch extends fdt_parse_aclint_node() to handle above
mentioned changes in ACLINT MTIMER DT bindings.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
We extend the ACLINT library to support separate base addresses
for MTIME and MTIMECMP registers.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
We add a new FDT based ACLINT MTIMER driver which works for
both CLINT device and standalone ACLINT MTIMER device.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Xiang W <wxjstz@126.com>
