nuttx/arch
Marco Casaroli b00d7005b0 rp23xx: Add /dev/timer driver on the TIMER0/TIMER1 blocks.
The RP2350 has two system timer blocks (TIMER0, TIMER1), each a free-running
64-bit counter incremented once per microsecond by the TICKS block (set up in
rp23xx_clock.c).  They are independent of the ARM SysTick that drives the OS
tick, so they are free for application use, but the port had no driver for
them.

Add rp23xx_timer.c, a NuttX timer lower-half that binds a block to a
/dev/timerN device.  It uses ALARM0 of the block, which matches the low 32
bits of the microsecond counter, to implement single-shot and periodic
timeouts with 1 us resolution and a maximum interval of 2^32 - 1 us (~71.5
minutes).  Periodic reloads are scheduled relative to the previous expiry to
avoid drift, but never behind the counter (an alarm set in the past would not
match until the 32-bit counter wraps).

Enable with CONFIG_RP23XX_TIMER (which selects CONFIG_TIMER), then turn on each
block independently: CONFIG_RP23XX_TIMER0 registers /dev/timer0 and
CONFIG_RP23XX_TIMER1 registers /dev/timer1.  A block claimed by the tickless
oneshot (CONFIG_RP23XX_SYSTIMER_TICKLESS) is excluded from these choices in
Kconfig, so the two features can be enabled together without colliding on the
same block or its alarm IRQ.

Tested on Pimoroni Pico Plus 2 (RP2350B) hardware with examples/timer and a
CMSIS-DAP probe.  The device registers as /dev/timer0; the ALARM0 interrupt
fires at the programmed period (verified over SWD at the configured 1 s
interval, not a busy loop), and the full path -- alarm match, the driver ISR,
the timer notification and delivery of the SIGNO to user space -- reaches the
example's signal handler and increments its counter.

Assisted-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Signed-off-by: Marco Casaroli <marco.casaroli@gmail.com>
2026-07-25 12:58:40 -03:00
..
arm rp23xx: Add /dev/timer driver on the TIMER0/TIMER1 blocks. 2026-07-25 12:58:40 -03:00
arm64 fs/hostfs: Return ENOTTY for unsupported ioctl 2026-07-23 08:30:29 +02:00
avr arch/avr/src/avrdx/avrdx_delay: add custom up_udelay function 2026-06-12 09:55:11 -04:00
ceva arch/ceva: Replace board_app_initialize 2026-05-02 18:36:46 +08:00
dummy
hc style: fix checkpatch issues after debug.h move 2026-04-07 07:50:06 -03:00
mips arch/mips/jz4780: Add USB host and display controller drivers 2026-07-24 12:17:35 +08:00
misoc include/debug.h: Move to include/nuttx/debug.h 2026-04-07 07:50:06 -03:00
or1k include/debug.h: Move to include/nuttx/debug.h 2026-04-07 07:50:06 -03:00
renesas drivers/efuse/efuse: Drivers Registered With World Write Permissions(Part 1) 2026-07-13 12:08:01 +02:00
risc-v fs/hostfs: Return ENOTTY for unsupported ioctl 2026-07-23 08:30:29 +02:00
sim arch/sim: Add PTY mode for simulated UART 2026-07-25 15:03:56 +08:00
sparc drivers: Fix comment typos — 'Pubic' → 'Public' across drivers and headers. 2026-07-02 13:29:48 +08:00
tricore arch/tricore: Add hardware debug breakpoint and watchpoint support. 2026-05-22 15:38:36 +08:00
x86 drivers/efuse/efuse: Drivers Registered With World Write Permissions(Part 1) 2026-07-13 12:08:01 +02:00
x86_64 !include/fcntl.h: align open flags with Linux values 2026-06-30 13:43:44 +08:00
xtensa fs/hostfs: Return ENOTTY for unsupported ioctl 2026-07-23 08:30:29 +02:00
z16 include/debug.h: Move to include/nuttx/debug.h 2026-04-07 07:50:06 -03:00
z80 style: fix checkpatch issues after debug.h move 2026-04-07 07:50:06 -03:00
CMakeLists.txt arch/z80: migrate to SPDX identifier 2024-12-02 17:23:25 +08:00
Kconfig sched/clock/clock_delay: added config flag to remove weak up_udelay 2026-06-12 09:55:11 -04:00