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From: Peter Maydell <peter.maydell@linaro.org>
To: qemu-devel@nongnu.org
Subject: [PULL 50/51] hw/timer/stellaris-gptm: Use Clock input instead of system_clock_scale
Date: Wed,  1 Sep 2021 11:36:52 +0100	[thread overview]
Message-ID: <20210901103653.13435-51-peter.maydell@linaro.org> (raw)
In-Reply-To: <20210901103653.13435-1-peter.maydell@linaro.org>

The stellaris-gptm timer currently uses system_clock_scale for one of
its timer modes where the timer runs at the CPU clock rate.  Make it
use a Clock input instead.

We don't try to make the timer handle changes in the clock frequency
while the downcounter is running.  This is not a change in behaviour
from the previous system_clock_scale implementation -- we will pick
up the new frequency only when the downcounter hits zero.  Handling
dynamic clock changes when the counter is running would require state
that the current gptm implementation doesn't have.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Damien Hedde <damien.hedde@greensocs.com>
Message-id: 20210812093356.1946-25-peter.maydell@linaro.org
---
 include/hw/timer/stellaris-gptm.h |  3 +++
 hw/arm/stellaris.c                | 12 +++++++++---
 hw/timer/stellaris-gptm.c         | 26 ++++++++++++++++++++++----
 3 files changed, 34 insertions(+), 7 deletions(-)

diff --git a/include/hw/timer/stellaris-gptm.h b/include/hw/timer/stellaris-gptm.h
index b8fa43c94bf..fde1fc6f0c7 100644
--- a/include/hw/timer/stellaris-gptm.h
+++ b/include/hw/timer/stellaris-gptm.h
@@ -13,6 +13,7 @@
 #include "qom/object.h"
 #include "hw/sysbus.h"
 #include "hw/irq.h"
+#include "hw/clock.h"
 
 #define TYPE_STELLARIS_GPTM "stellaris-gptm"
 OBJECT_DECLARE_SIMPLE_TYPE(gptm_state, STELLARIS_GPTM)
@@ -22,6 +23,7 @@ OBJECT_DECLARE_SIMPLE_TYPE(gptm_state, STELLARIS_GPTM)
  *  + sysbus MMIO region 0: register bank
  *  + sysbus IRQ 0: timer interrupt
  *  + unnamed GPIO output 0: trigger output for the ADC
+ *  + Clock input "clk": the 32-bit countdown timer runs at this speed
  */
 struct gptm_state {
     SysBusDevice parent_obj;
@@ -43,6 +45,7 @@ struct gptm_state {
     /* The timers have an alternate output used to trigger the ADC.  */
     qemu_irq trigger;
     qemu_irq irq;
+    Clock *clk;
 };
 
 #endif
diff --git a/hw/arm/stellaris.c b/hw/arm/stellaris.c
index 8c547f146a9..3e7d1dabad1 100644
--- a/hw/arm/stellaris.c
+++ b/hw/arm/stellaris.c
@@ -1090,9 +1090,15 @@ static void stellaris_init(MachineState *ms, stellaris_board_info *board)
     }
     for (i = 0; i < 4; i++) {
         if (board->dc2 & (0x10000 << i)) {
-            dev = sysbus_create_simple(TYPE_STELLARIS_GPTM,
-                                       0x40030000 + i * 0x1000,
-                                       qdev_get_gpio_in(nvic, timer_irq[i]));
+            SysBusDevice *sbd;
+
+            dev = qdev_new(TYPE_STELLARIS_GPTM);
+            sbd = SYS_BUS_DEVICE(dev);
+            qdev_connect_clock_in(dev, "clk",
+                                  qdev_get_clock_out(ssys_dev, "SYSCLK"));
+            sysbus_realize_and_unref(sbd, &error_fatal);
+            sysbus_mmio_map(sbd, 0, 0x40030000 + i * 0x1000);
+            sysbus_connect_irq(sbd, 0, qdev_get_gpio_in(nvic, timer_irq[i]));
             /* TODO: This is incorrect, but we get away with it because
                the ADC output is only ever pulsed.  */
             qdev_connect_gpio_out(dev, 0, adc);
diff --git a/hw/timer/stellaris-gptm.c b/hw/timer/stellaris-gptm.c
index 7846fe5f84e..fd71c79be48 100644
--- a/hw/timer/stellaris-gptm.c
+++ b/hw/timer/stellaris-gptm.c
@@ -10,9 +10,10 @@
 #include "qemu/osdep.h"
 #include "qemu/log.h"
 #include "qemu/timer.h"
+#include "qapi/error.h"
 #include "migration/vmstate.h"
+#include "hw/qdev-clock.h"
 #include "hw/timer/stellaris-gptm.h"
-#include "hw/timer/armv7m_systick.h" /* Needed only for system_clock_scale */
 
 static void gptm_update_irq(gptm_state *s)
 {
@@ -39,7 +40,7 @@ static void gptm_reload(gptm_state *s, int n, int reset)
         /* 32-bit CountDown.  */
         uint32_t count;
         count = s->load[0] | (s->load[1] << 16);
-        tick += (int64_t)count * system_clock_scale;
+        tick += clock_ticks_to_ns(s->clk, count);
     } else if (s->config == 1) {
         /* 32-bit RTC.  1Hz tick.  */
         tick += NANOSECONDS_PER_SECOND;
@@ -247,8 +248,8 @@ static const MemoryRegionOps gptm_ops = {
 
 static const VMStateDescription vmstate_stellaris_gptm = {
     .name = "stellaris_gptm",
-    .version_id = 1,
-    .minimum_version_id = 1,
+    .version_id = 2,
+    .minimum_version_id = 2,
     .fields = (VMStateField[]) {
         VMSTATE_UINT32(config, gptm_state),
         VMSTATE_UINT32_ARRAY(mode, gptm_state, 2),
@@ -263,6 +264,7 @@ static const VMStateDescription vmstate_stellaris_gptm = {
         VMSTATE_UINT32(rtc, gptm_state),
         VMSTATE_INT64_ARRAY(tick, gptm_state, 2),
         VMSTATE_TIMER_PTR_ARRAY(timer, gptm_state, 2),
+        VMSTATE_CLOCK(clk, gptm_state),
         VMSTATE_END_OF_LIST()
     }
 };
@@ -281,11 +283,27 @@ static void stellaris_gptm_init(Object *obj)
     sysbus_init_mmio(sbd, &s->iomem);
 
     s->opaque[0] = s->opaque[1] = s;
+
+    /*
+     * TODO: in an ideal world we would model the effects of changing
+     * the input clock frequency while the countdown timer is active.
+     * The best way to do this would be to convert the device to use
+     * ptimer instead of hand-rolling its own timer. This would also
+     * make it easy to implement reading the current count from the
+     * TAR and TBR registers.
+     */
+    s->clk = qdev_init_clock_in(dev, "clk", NULL, NULL, 0);
 }
 
 static void stellaris_gptm_realize(DeviceState *dev, Error **errp)
 {
     gptm_state *s = STELLARIS_GPTM(dev);
+
+    if (!clock_has_source(s->clk)) {
+        error_setg(errp, "stellaris-gptm: clk must be connected");
+        return;
+    }
+
     s->timer[0] = timer_new_ns(QEMU_CLOCK_VIRTUAL, gptm_tick, &s->opaque[0]);
     s->timer[1] = timer_new_ns(QEMU_CLOCK_VIRTUAL, gptm_tick, &s->opaque[1]);
 }
-- 
2.20.1



  parent reply	other threads:[~2021-09-01 11:25 UTC|newest]

Thread overview: 53+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-01 10:36 [PULL 00/51] target-arm queue Peter Maydell
2021-09-01 10:36 ` [PULL 01/51] tests: Remove uses of deprecated raspi2/raspi3 machine names Peter Maydell
2021-09-01 10:36 ` [PULL 02/51] hw/arm/raspi: Remove deprecated raspi2/raspi3 aliases Peter Maydell
2021-09-01 10:36 ` [PULL 03/51] hw/intc/arm_gicv3_dist: Rename 64-bit accessors with 'q' suffix Peter Maydell
2021-09-01 10:36 ` [PULL 04/51] hw/intc/arm_gicv3: Replace mis-used MEMTX_* constants by booleans Peter Maydell
2021-09-01 10:36 ` [PULL 05/51] hw: Add compat machines for 6.2 Peter Maydell
2021-09-01 10:36 ` [PULL 06/51] target/arm: Implement MVE VADD (floating-point) Peter Maydell
2021-09-01 10:36 ` [PULL 07/51] target/arm: Implement MVE VSUB, VMUL, VABD, VMAXNM, VMINNM Peter Maydell
2021-09-01 10:36 ` [PULL 08/51] target/arm: Implement MVE VCADD Peter Maydell
2021-09-01 10:36 ` [PULL 09/51] target/arm: Implement MVE VFMA and VFMS Peter Maydell
2021-09-01 10:36 ` [PULL 10/51] target/arm: Implement MVE VCMUL and VCMLA Peter Maydell
2021-09-01 10:36 ` [PULL 11/51] target/arm: Implement MVE VMAXNMA and VMINNMA Peter Maydell
2021-09-01 10:36 ` [PULL 12/51] target/arm: Implement MVE scalar fp insns Peter Maydell
2021-09-01 10:36 ` [PULL 13/51] target/arm: Implement MVE fp-with-scalar VFMA, VFMAS Peter Maydell
2021-09-01 10:36 ` [PULL 14/51] softfloat: Remove assertion preventing silencing of NaN in default-NaN mode Peter Maydell
2021-09-01 10:36 ` [PULL 15/51] target/arm: Implement MVE FP max/min across vector Peter Maydell
2021-09-01 10:36 ` [PULL 16/51] target/arm: Implement MVE fp vector comparisons Peter Maydell
2021-09-01 10:36 ` [PULL 17/51] target/arm: Implement MVE fp scalar comparisons Peter Maydell
2021-09-01 10:36 ` [PULL 18/51] target/arm: Implement MVE VCVT between floating and fixed point Peter Maydell
2021-09-01 10:36 ` [PULL 19/51] target/arm: Implement MVE VCVT between fp and integer Peter Maydell
2021-09-01 10:36 ` [PULL 20/51] target/arm: Implement MVE VCVT with specified rounding mode Peter Maydell
2021-09-01 10:36 ` [PULL 21/51] target/arm: Implement MVE VCVT between single and half precision Peter Maydell
2021-09-01 10:36 ` [PULL 22/51] target/arm: Implement MVE VRINT insns Peter Maydell
2021-09-01 10:36 ` [PULL 23/51] target/arm: Enable MVE in Cortex-M55 Peter Maydell
2021-09-01 10:36 ` [PULL 24/51] target-arm: Add support for Fujitsu A64FX Peter Maydell
2021-09-01 10:36 ` [PULL 25/51] hw/arm/virt: target-arm: Add A64FX processor support to virt machine Peter Maydell
2021-09-01 10:36 ` [PULL 26/51] tests/arm-cpu-features: Add A64FX processor related tests Peter Maydell
2021-09-01 10:36 ` [PULL 27/51] arm: Move M-profile RAS register block into its own device Peter Maydell
2021-09-01 10:36 ` [PULL 28/51] arm: Move systick device creation from NVIC to ARMv7M object Peter Maydell
2021-09-01 10:36 ` [PULL 29/51] arm: Move system PPB container handling to armv7m Peter Maydell
2021-09-01 10:36 ` [PULL 30/51] hw/timer/armv7m_systick: Add usual QEMU interface comment Peter Maydell
2021-09-01 10:36 ` [PULL 31/51] hw/timer/armv7m_systick: Add input clocks Peter Maydell
2021-09-01 10:36 ` [PULL 32/51] hw/arm/armv7m: Create " Peter Maydell
2021-09-01 10:36 ` [PULL 33/51] armsse: Wire up systick cpuclk clock Peter Maydell
2021-09-01 10:36 ` [PULL 34/51] hw/arm/mps2.c: Connect up armv7m clocks Peter Maydell
2021-09-01 10:36 ` [PULL 35/51] clock: Provide builtin multiplier/divider Peter Maydell
2021-09-01 10:36 ` [PULL 36/51] hw/arm: Don't allocate separate MemoryRegions in stm32 SoC realize Peter Maydell
2021-09-01 10:36 ` [PULL 37/51] hw/arm/stm32f100: Wire up sysclk and refclk Peter Maydell
2021-09-01 10:36 ` [PULL 38/51] hw/arm/stm32f205: " Peter Maydell
2021-09-01 10:36 ` [PULL 39/51] hw/arm/stm32f405: " Peter Maydell
2021-09-01 10:36 ` [PULL 40/51] hw/arm/stm32vldiscovery: Delete trailing blank line Peter Maydell
2021-09-01 10:36 ` [PULL 41/51] hw/arm/nrf51: Wire up sysclk Peter Maydell
2021-09-01 10:36 ` [PULL 42/51] hw/arm/stellaris: split stellaris_sys_init() Peter Maydell
2021-09-01 10:36 ` [PULL 43/51] hw/arm/stellaris: Wire sysclk up to armv7m Peter Maydell
2021-09-01 10:36 ` [PULL 44/51] hw/arm/msf2_soc: Don't allocate separate MemoryRegions Peter Maydell
2021-09-01 10:36 ` [PULL 45/51] hw/arm/msf2: Use Clock input to MSF2_SOC instead of m3clk property Peter Maydell
2021-09-01 10:36 ` [PULL 46/51] hw/arm/msf2-soc: Wire up refclk Peter Maydell
2021-09-01 10:36 ` [PULL 47/51] hw/timer/armv7m_systick: Use clock inputs instead of system_clock_scale Peter Maydell
2021-09-01 10:36 ` [PULL 48/51] hw/arm/stellaris: Fix code style issues in GPTM code Peter Maydell
2021-09-01 10:36 ` [PULL 49/51] hw/arm/stellaris: Split stellaris-gptm into its own file Peter Maydell
2021-09-01 10:36 ` Peter Maydell [this message]
2021-09-01 10:36 ` [PULL 51/51] arm: Remove system_clock_scale global Peter Maydell
2021-09-02  7:48 ` [PULL 00/51] target-arm queue Peter Maydell

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