Currently, the platform's timer device is tracked in two places: the
core SBI implementation has `timer_dev`, and the FDT timer layer has
`current_driver`. The latter is used for warm initialization of the
timer device. However, this warm init is not specific to FDT-based
platforms; other platforms call exactly the same functions from the
same point in the boot sequence.
The code is simplified and made common across platforms by treating warm
init and exit as properties of the driver, not the platform. Then the
platform's only role is to select and prepare a driver during cold boot.
For now, only add a .warm_init hook, since none of the existing drivers
need an .exit hook. It could be added in the future if needed.
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Writes to the low half CSR should not affect the high half of the value.
Make this separation explicit by writing to the delta in memory as two
adjacent XLEN-sized values.
Fixes: 1e9f88889f ("lib: Emulate HTIMEDELTA CSR for platforms not having TIME CSR")
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Motivation: Suppose a peripheral needs to be configured to transmit
data. There is an SFR bit which indicates that the peripheral is ready
to transmit. The firmware should check the bit and will only transmit
data when the peripheral is ready. When the firmware starts polling the
SFR, the peripheral could be busy transmitting/receiving other data so
the firmware must wait till that completes. Assuming that there is no
other way, the firmware shouldn't wait indefinitely.
The function sbi_timer_waitms_until() will constantly check whether a
certain condition is satisfied, or timeout occurs. It can be used for
the cases when a timeout is required.
Signed-off-by: Adnan Rahman Chowdhury <adnan.chowdhury@sifive.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
We now have frequency of the timer device provided by the platform
support so we can emulate desired delay using a loop where the number
loop iterations are based on timer frequency.
This patch provides sbi_timer_delay_loop() 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>
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>
Instead of having timer_value(), timer_event_start(), and
timer_event_stop() callbacks in platform operations, it will
be much simpler for timer driver to directly register these
operations as device to the sbi_timer implementation.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
We add sbi_timer_exit() API for OpenSBI exit path handling in
sbi_exit() implementation.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
For platforms not having TIME CSR, we trap-n-emulate TIME CSR
read/write in OpenSBI. Same rationale applies to HTIMEDELTA CSR
as well so we trap-n-emulate HTIMEDELTA CSR for platforms not
having TIME CSR.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
This patch updates copyright header in all files as follows:
1. Makes "SPDX-License-Identifier: BSD-2-Clause" as first line
2. Change copyright year to 2019 for Western Digital
Signed-off-by: Anup Patel <anup.patel@wdc.com>
The target_hart and hartid paramter of TIMER callbacks is not
required because it always current hartid which can be obtained
using sbi_current_hartid() API.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Instead of having separate timer_init() hooks for cold and
warm boot, this patch updates struct sbi_platform to have just
one timer_init() hook. The type of boot (cold or warm) is now
a boolean flag parameter for the updated timer_init() hook.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
