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Grab timer frequency from FDT.

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RISC-V timer has no dedicated DTS node and we have to get timer
frequency from cpus node.

Tested on Government Furnished Equipment (GFE) cores synthesized
on Xilinx VCU118.

Reviewed by:	markj
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D19727
This commit is contained in:
Ruslan Bukin 2019-03-27 16:26:03 +00:00
parent 77c2fe20df
commit 61fef9e860
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=345581
1 changed files with 32 additions and 4 deletions
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36
sys/riscv/riscv/timer.c
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@ -61,7 +61,10 @@ __FBSDID("$FreeBSD$");
#include <machine/trap.h>
#include <machine/sbi.h>
#define DEFAULT_FREQ 10000000
#include <dev/fdt/fdt_common.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <dev/ofw/openfirm.h>
#define TIMER_COUNTS 0x00
#define TIMER_MTIMECMP(cpu) (cpu * 8)
@ -156,6 +159,32 @@ riscv_timer_intr(void *arg)
return (FILTER_HANDLED);
}
static int
riscv_timer_get_timebase(device_t dev, uint32_t *freq)
{
phandle_t node;
int len;
node = OF_finddevice("/cpus");
if (node == -1) {
if (bootverbose)
device_printf(dev, "Can't find cpus node.\n");
return (ENXIO);
}
len = OF_getproplen(node, "timebase-frequency");
if (len != 4) {
if (bootverbose)
device_printf(dev,
"Can't find timebase-frequency property.\n");
return (ENXIO);
}
OF_getencprop(node, "timebase-frequency", freq, len);
return (0);
}
static int
riscv_timer_probe(device_t dev)
{
@ -176,10 +205,9 @@ riscv_timer_attach(device_t dev)
return (ENXIO);
if (device_get_unit(dev) != 0)
return ENXIO;
return (ENXIO);
sc->clkfreq = DEFAULT_FREQ;
if (sc->clkfreq == 0) {
if (riscv_timer_get_timebase(dev, &sc->clkfreq) != 0) {
device_printf(dev, "No clock frequency specified\n");
return (ENXIO);
}