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authorPeter Maydell2021-09-01 18:45:38 +0200
committerPeter Maydell2021-09-01 18:45:38 +0200
commit079b1252e9de384385c9da910262312ec2e574c8 (patch)
treeb18dfec9ce1edd5412bac5bc612f0c2989eacb01 /include/hw/clock.h
parentMerge remote-tracking branch 'remotes/kraxel/tags/usb-20210901-pull-request' ... (diff)
parentarm: Remove system_clock_scale global (diff)
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Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20210901' into staging
* Refactor M-profile systick to use Clocks instead of system_clock_scale global * clock: Provide builtin multiplier/divider * Add A64FX processor model * Enable MVE emulation in Cortex-M55 * hw: Add compat machines for 6.2 * hw/intc/arm_gicv3: Replace mis-used MEMTX_* constants by booleans * hw/arm/raspi: Remove deprecated raspi2/raspi3 aliases # gpg: Signature made Wed 01 Sep 2021 11:35:57 BST # gpg: using RSA key E1A5C593CD419DE28E8315CF3C2525ED14360CDE # gpg: issuer "peter.maydell@linaro.org" # gpg: Good signature from "Peter Maydell <peter.maydell@linaro.org>" [ultimate] # gpg: aka "Peter Maydell <pmaydell@gmail.com>" [ultimate] # gpg: aka "Peter Maydell <pmaydell@chiark.greenend.org.uk>" [ultimate] # Primary key fingerprint: E1A5 C593 CD41 9DE2 8E83 15CF 3C25 25ED 1436 0CDE * remotes/pmaydell/tags/pull-target-arm-20210901: (51 commits) arm: Remove system_clock_scale global hw/timer/stellaris-gptm: Use Clock input instead of system_clock_scale hw/arm/stellaris: Split stellaris-gptm into its own file hw/arm/stellaris: Fix code style issues in GPTM code hw/timer/armv7m_systick: Use clock inputs instead of system_clock_scale hw/arm/msf2-soc: Wire up refclk hw/arm/msf2: Use Clock input to MSF2_SOC instead of m3clk property hw/arm/msf2_soc: Don't allocate separate MemoryRegions hw/arm/stellaris: Wire sysclk up to armv7m hw/arm/stellaris: split stellaris_sys_init() hw/arm/nrf51: Wire up sysclk hw/arm/stm32vldiscovery: Delete trailing blank line hw/arm/stm32f405: Wire up sysclk and refclk hw/arm/stm32f205: Wire up sysclk and refclk hw/arm/stm32f100: Wire up sysclk and refclk hw/arm: Don't allocate separate MemoryRegions in stm32 SoC realize clock: Provide builtin multiplier/divider hw/arm/mps2.c: Connect up armv7m clocks armsse: Wire up systick cpuclk clock hw/arm/armv7m: Create input clocks ... Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'include/hw/clock.h')
-rw-r--r--include/hw/clock.h29
1 files changed, 29 insertions, 0 deletions
diff --git a/include/hw/clock.h b/include/hw/clock.h
index a7187eab95..11f67fb970 100644
--- a/include/hw/clock.h
+++ b/include/hw/clock.h
@@ -81,6 +81,10 @@ struct Clock {
void *callback_opaque;
unsigned int callback_events;
+ /* Ratio of the parent clock to run the child clocks at */
+ uint32_t multiplier;
+ uint32_t divider;
+
/* Clocks are organized in a clock tree */
Clock *source;
QLIST_HEAD(, Clock) children;
@@ -350,4 +354,29 @@ static inline bool clock_is_enabled(const Clock *clk)
*/
char *clock_display_freq(Clock *clk);
+/**
+ * clock_set_mul_div: set multiplier/divider for child clocks
+ * @clk: clock
+ * @multiplier: multiplier value
+ * @divider: divider value
+ *
+ * By default, a Clock's children will all run with the same period
+ * as their parent. This function allows you to adjust the multiplier
+ * and divider used to derive the child clock frequency.
+ * For example, setting a multiplier of 2 and a divider of 3
+ * will run child clocks with a period 2/3 of the parent clock,
+ * so if the parent clock is an 8MHz clock the children will
+ * be 12MHz.
+ *
+ * Setting the multiplier to 0 will stop the child clocks.
+ * Setting the divider to 0 is a programming error (diagnosed with
+ * an assertion failure).
+ * Setting a multiplier value that results in the child period
+ * overflowing is not diagnosed.
+ *
+ * Note that this function does not call clock_propagate(); the
+ * caller should do that if necessary.
+ */
+void clock_set_mul_div(Clock *clk, uint32_t multiplier, uint32_t divider);
+
#endif /* QEMU_HW_CLOCK_H */