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authorPeter Maydell <peter.maydell@linaro.org>2021-08-12 10:33:51 +0100
committerPeter Maydell <peter.maydell@linaro.org>2021-09-01 11:08:20 +0100
commit3b76e18520330e2a23c86d7c627c1cd4a3ed32f2 (patch)
treebdab5e9a7671c5496f0c2e67eb5dc4dfaed0c518
parent9bfaf3754b71b72296f24f73876da67cf43c3e10 (diff)
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hw/arm/msf2-soc: Wire up refclk
Wire up the refclk for the msf2 SoC. This SoC runs the refclk at a frequency which is programmably either /4, /8, /16 or /32 of the main CPU clock. We don't currently model the register which allows the guest to set the divisor, so implement the refclk as a fixed /32 of the CPU clock (which is the value of the divisor at reset). Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Damien Hedde <damien.hedde@greensocs.com> Message-id: 20210812093356.1946-21-peter.maydell@linaro.org
-rw-r--r--hw/arm/msf2-soc.c23
-rw-r--r--include/hw/arm/msf2-soc.h1
2 files changed, 24 insertions, 0 deletions
diff --git a/hw/arm/msf2-soc.c b/hw/arm/msf2-soc.c
index 0a1e594..dbc6d93 100644
--- a/hw/arm/msf2-soc.c
+++ b/hw/arm/msf2-soc.c
@@ -76,6 +76,7 @@ static void m2sxxx_soc_initfn(Object *obj)
object_initialize_child(obj, "emac", &s->emac, TYPE_MSS_EMAC);
s->m3clk = qdev_init_clock_in(DEVICE(obj), "m3clk", NULL, NULL, 0);
+ s->refclk = qdev_init_clock_in(DEVICE(obj), "refclk", NULL, NULL, 0);
}
static void m2sxxx_soc_realize(DeviceState *dev_soc, Error **errp)
@@ -92,6 +93,27 @@ static void m2sxxx_soc_realize(DeviceState *dev_soc, Error **errp)
return;
}
+ /*
+ * We use s->refclk internally and only define it with qdev_init_clock_in()
+ * so it is correctly parented and not leaked on an init/deinit; it is not
+ * intended as an externally exposed clock.
+ */
+ if (clock_has_source(s->refclk)) {
+ error_setg(errp, "refclk must not be wired up by the board code");
+ return;
+ }
+
+ /*
+ * TODO: ideally we should model the SoC SYSTICK_CR register at 0xe0042038,
+ * which allows the guest to program the divisor between the m3clk and
+ * the systick refclk to either /4, /8, /16 or /32, as well as setting
+ * the value the guest can read in the STCALIB register. Currently we
+ * implement the divisor as a fixed /32, which matches the reset value
+ * of SYSTICK_CR.
+ */
+ clock_set_mul_div(s->refclk, 32, 1);
+ clock_set_source(s->refclk, s->m3clk);
+
memory_region_init_rom(&s->nvm, OBJECT(dev_soc), "MSF2.eNVM", s->envm_size,
&error_fatal);
/*
@@ -115,6 +137,7 @@ static void m2sxxx_soc_realize(DeviceState *dev_soc, Error **errp)
qdev_prop_set_string(armv7m, "cpu-type", s->cpu_type);
qdev_prop_set_bit(armv7m, "enable-bitband", true);
qdev_connect_clock_in(armv7m, "cpuclk", s->m3clk);
+ qdev_connect_clock_in(armv7m, "refclk", s->refclk);
object_property_set_link(OBJECT(&s->armv7m), "memory",
OBJECT(get_system_memory()), &error_abort);
if (!sysbus_realize(SYS_BUS_DEVICE(&s->armv7m), errp)) {
diff --git a/include/hw/arm/msf2-soc.h b/include/hw/arm/msf2-soc.h
index 01f904c..ce417a6 100644
--- a/include/hw/arm/msf2-soc.h
+++ b/include/hw/arm/msf2-soc.h
@@ -59,6 +59,7 @@ struct MSF2State {
uint64_t esram_size;
Clock *m3clk;
+ Clock *refclk;
uint8_t apb0div;
uint8_t apb1div;