diff options
| author | Sean Anderson <seanga2@gmail.com> | 2020-09-28 17:52:22 +0300 |
|---|---|---|
| committer | Andes <uboot@andestech.com> | 2020-09-30 03:54:45 +0300 |
| commit | 3576121687965ffe580fc44f5dd1d8e9ab434c5b (patch) | |
| tree | 7c9b33bba348375cd647da2f7f03891b34b9622e | |
| parent | c33efafaf949ef11fc525cd5be018ea48c40898c (diff) | |
| download | u-boot-3576121687965ffe580fc44f5dd1d8e9ab434c5b.tar.xz | |
timer: Add helper for drivers using timebase fallback
This function is designed to be used when a timer used to be initialized by
the cpu (e.g. RISC-V timers), but now is initialized by dm_timer_init. In
such a case, the timer may prefer to use the clocks and clock-frequency
properties, but should be able to fall back on using the cpu's
timebase-frequency.
Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Rick Chen <rick@andestech.com>
| -rw-r--r-- | drivers/timer/timer-uclass.c | 31 | ||||
| -rw-r--r-- | include/timer.h | 15 |
2 files changed, 46 insertions, 0 deletions
diff --git a/drivers/timer/timer-uclass.c b/drivers/timer/timer-uclass.c index 14dde950a1..e9802c8b43 100644 --- a/drivers/timer/timer-uclass.c +++ b/drivers/timer/timer-uclass.c @@ -4,6 +4,7 @@ */ #include <common.h> +#include <cpu.h> #include <dm.h> #include <init.h> #include <dm/lists.h> @@ -79,6 +80,36 @@ static int timer_post_probe(struct udevice *dev) return 0; } +/* + * TODO: should be CONFIG_IS_ENABLED(CPU), but the SPL config has _SUPPORT on + * the end... + */ +#if defined(CONFIG_CPU) || defined(CONFIG_SPL_CPU_SUPPORT) +int timer_timebase_fallback(struct udevice *dev) +{ + struct udevice *cpu; + struct cpu_platdata *cpu_plat; + struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev); + + /* Did we get our clock rate from the device tree? */ + if (uc_priv->clock_rate) + return 0; + + /* Fall back to timebase-frequency */ + dev_dbg(dev, "missing clocks or clock-frequency property; falling back on timebase-frequency\n"); + cpu = cpu_get_current_dev(); + if (!cpu) + return -ENODEV; + + cpu_plat = dev_get_parent_platdata(cpu); + if (!cpu_plat) + return -ENODEV; + + uc_priv->clock_rate = cpu_plat->timebase_freq; + return 0; +} +#endif + u64 timer_conv_64(u32 count) { /* increment tbh if tbl has rolled over */ diff --git a/include/timer.h b/include/timer.h index a49b500ce3..8b9fa51c53 100644 --- a/include/timer.h +++ b/include/timer.h @@ -15,6 +15,21 @@ */ int dm_timer_init(void); +/** + * timer_timebase_fallback() - Helper for timers using timebase fallback + * @dev: A timer partially-probed timer device + * + * This is a helper function designed for timers which need to fall back on the + * cpu's timebase. This function is designed to be called during the driver's + * probe(). If there is a clocks or clock-frequency property in the timer's + * binding, then it will be used. Otherwise, the timebase of the current cpu + * will be used. This is initialized by the cpu driver, and usually gotten from + * ``/cpus/timebase-frequency`` or ``/cpus/cpu@X/timebase-frequency``. + * + * Return: 0 if OK, or negative error code on failure + */ +int timer_timebase_fallback(struct udevice *dev); + /* * timer_conv_64 - convert 32-bit counter value to 64-bit * |