clock: Add ClockEvent parameter to callbacks

The Clock framework allows users to specify a callback which is
called after the clock's period has been updated.  Some users need to
also have a callback which is called before the clock period is
updated.

As the first step in adding support for notifying Clock users on
pre-update events, add an argument to the ClockCallback to specify
what event is being notified, and add an argument to the various
functions for registering a callback to specify which events are
of interest to that callback.

Note that the documentation update renders correct the previously
incorrect claim in 'Adding a new clock' that callbacks "will be
explained in a following section".

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Luc Michel <luc@lmichel.fr>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210219144617.4782-2-peter.maydell@linaro.org

4 files changed, 40 insertions, 16 deletions

diff --git a/hw/misc/bcm2835_cprman.c b/hw/misc/bcm2835_cprman.c
index 7e415a017c..75e6c574d4 100644
--- a/hw/misc/bcm2835_cprman.c
+++ b/hw/misc/bcm2835_cprman.c
@@ -107,7 +107,7 @@ static void pll_update(CprmanPllState *pll)
     clock_update_hz(pll->out, freq);
 }
 
-static void pll_xosc_update(void *opaque)
+static void pll_xosc_update(void *opaque, ClockEvent event)
 {
     pll_update(CPRMAN_PLL(opaque));
 }
@@ -116,7 +116,8 @@ static void pll_init(Object *obj)
 {
     CprmanPllState *s = CPRMAN_PLL(obj);
 
-    s->xosc_in = qdev_init_clock_in(DEVICE(s), "xosc-in", pll_xosc_update, s);
+    s->xosc_in = qdev_init_clock_in(DEVICE(s), "xosc-in", pll_xosc_update,
+                                    s, ClockUpdate);
     s->out = qdev_init_clock_out(DEVICE(s), "out");
 }
 
@@ -209,7 +210,7 @@ static void pll_update_all_channels(BCM2835CprmanState *s,
     }
 }
 
-static void pll_channel_pll_in_update(void *opaque)
+static void pll_channel_pll_in_update(void *opaque, ClockEvent event)
 {
     pll_channel_update(CPRMAN_PLL_CHANNEL(opaque));
 }
@@ -219,7 +220,8 @@ static void pll_channel_init(Object *obj)
     CprmanPllChannelState *s = CPRMAN_PLL_CHANNEL(obj);
 
     s->pll_in = qdev_init_clock_in(DEVICE(s), "pll-in",
-                                   pll_channel_pll_in_update, s);
+                                   pll_channel_pll_in_update, s,
+                                   ClockUpdate);
     s->out = qdev_init_clock_out(DEVICE(s), "out");
 }
 
@@ -303,7 +305,7 @@ static void clock_mux_update(CprmanClockMuxState *mux)
     clock_update_hz(mux->out, freq);
 }
 
-static void clock_mux_src_update(void *opaque)
+static void clock_mux_src_update(void *opaque, ClockEvent event)
 {
     CprmanClockMuxState **backref = opaque;
     CprmanClockMuxState *s = *backref;
@@ -335,7 +337,8 @@ static void clock_mux_init(Object *obj)
         s->backref[i] = s;
         s->srcs[i] = qdev_init_clock_in(DEVICE(s), name,
                                         clock_mux_src_update,
-                                        &s->backref[i]);
+                                        &s->backref[i],
+                                        ClockUpdate);
         g_free(name);
     }
 
@@ -380,7 +383,7 @@ static void dsi0hsck_mux_update(CprmanDsi0HsckMuxState *s)
     clock_update(s->out, clock_get(src));
 }
 
-static void dsi0hsck_mux_in_update(void *opaque)
+static void dsi0hsck_mux_in_update(void *opaque, ClockEvent event)
 {
     dsi0hsck_mux_update(CPRMAN_DSI0HSCK_MUX(opaque));
 }
@@ -390,8 +393,10 @@ static void dsi0hsck_mux_init(Object *obj)
     CprmanDsi0HsckMuxState *s = CPRMAN_DSI0HSCK_MUX(obj);
     DeviceState *dev = DEVICE(obj);
 
-    s->plla_in = qdev_init_clock_in(dev, "plla-in", dsi0hsck_mux_in_update, s);
-    s->plld_in = qdev_init_clock_in(dev, "plld-in", dsi0hsck_mux_in_update, s);
+    s->plla_in = qdev_init_clock_in(dev, "plla-in", dsi0hsck_mux_in_update,
+                                    s, ClockUpdate);
+    s->plld_in = qdev_init_clock_in(dev, "plld-in", dsi0hsck_mux_in_update,
+                                    s, ClockUpdate);
     s->out = qdev_init_clock_out(DEVICE(s), "out");
 }
 
diff --git a/hw/misc/npcm7xx_clk.c b/hw/misc/npcm7xx_clk.c
index 0bcae9ce95..a1ee67dc9a 100644
--- a/hw/misc/npcm7xx_clk.c
+++ b/hw/misc/npcm7xx_clk.c
@@ -586,15 +586,26 @@ static const DividerInitInfo divider_init_info_list[] = {
     },
 };
 
+static void npcm7xx_clk_update_pll_cb(void *opaque, ClockEvent event)
+{
+    npcm7xx_clk_update_pll(opaque);
+}
+
 static void npcm7xx_clk_pll_init(Object *obj)
 {
     NPCM7xxClockPLLState *pll = NPCM7XX_CLOCK_PLL(obj);
 
     pll->clock_in = qdev_init_clock_in(DEVICE(pll), "clock-in",
-            npcm7xx_clk_update_pll, pll);
+                                       npcm7xx_clk_update_pll_cb, pll,
+                                       ClockUpdate);
     pll->clock_out = qdev_init_clock_out(DEVICE(pll), "clock-out");
 }
 
+static void npcm7xx_clk_update_sel_cb(void *opaque, ClockEvent event)
+{
+    npcm7xx_clk_update_sel(opaque);
+}
+
 static void npcm7xx_clk_sel_init(Object *obj)
 {
     int i;
@@ -603,16 +614,23 @@ static void npcm7xx_clk_sel_init(Object *obj)
     for (i = 0; i < NPCM7XX_CLK_SEL_MAX_INPUT; ++i) {
         sel->clock_in[i] = qdev_init_clock_in(DEVICE(sel),
                 g_strdup_printf("clock-in[%d]", i),
-                npcm7xx_clk_update_sel, sel);
+                npcm7xx_clk_update_sel_cb, sel, ClockUpdate);
     }
     sel->clock_out = qdev_init_clock_out(DEVICE(sel), "clock-out");
 }
+
+static void npcm7xx_clk_update_divider_cb(void *opaque, ClockEvent event)
+{
+    npcm7xx_clk_update_divider(opaque);
+}
+
 static void npcm7xx_clk_divider_init(Object *obj)
 {
     NPCM7xxClockDividerState *div = NPCM7XX_CLOCK_DIVIDER(obj);
 
     div->clock_in = qdev_init_clock_in(DEVICE(div), "clock-in",
-            npcm7xx_clk_update_divider, div);
+                                       npcm7xx_clk_update_divider_cb,
+                                       div, ClockUpdate);
     div->clock_out = qdev_init_clock_out(DEVICE(div), "clock-out");
 }
 
@@ -875,7 +893,7 @@ static void npcm7xx_clk_init_clock_hierarchy(NPCM7xxCLKState *s)
 {
     int i;
 
-    s->clkref = qdev_init_clock_in(DEVICE(s), "clkref", NULL, NULL);
+    s->clkref = qdev_init_clock_in(DEVICE(s), "clkref", NULL, NULL, 0);
 
     /* First pass: init all converter modules */
     QEMU_BUILD_BUG_ON(ARRAY_SIZE(pll_init_info_list) != NPCM7XX_CLOCK_NR_PLLS);
diff --git a/hw/misc/npcm7xx_pwm.c b/hw/misc/npcm7xx_pwm.c
index dabcb6c0f9..ce192bb274 100644
--- a/hw/misc/npcm7xx_pwm.c
+++ b/hw/misc/npcm7xx_pwm.c
@@ -493,7 +493,7 @@ static void npcm7xx_pwm_init(Object *obj)
     memory_region_init_io(&s->iomem, obj, &npcm7xx_pwm_ops, s,
                           TYPE_NPCM7XX_PWM, 4 * KiB);
     sysbus_init_mmio(sbd, &s->iomem);
-    s->clock = qdev_init_clock_in(DEVICE(s), "clock", NULL, NULL);
+    s->clock = qdev_init_clock_in(DEVICE(s), "clock", NULL, NULL, 0);
 
     for (i = 0; i < NPCM7XX_PWM_PER_MODULE; ++i) {
         object_property_add_uint32_ptr(obj, "freq[*]",
diff --git a/hw/misc/zynq_slcr.c b/hw/misc/zynq_slcr.c
index 66504a9d3a..c66d7db177 100644
--- a/hw/misc/zynq_slcr.c
+++ b/hw/misc/zynq_slcr.c
@@ -307,9 +307,10 @@ static void zynq_slcr_propagate_clocks(ZynqSLCRState *s)
     clock_propagate(s->uart1_ref_clk);
 }
 
-static void zynq_slcr_ps_clk_callback(void *opaque)
+static void zynq_slcr_ps_clk_callback(void *opaque, ClockEvent event)
 {
     ZynqSLCRState *s = (ZynqSLCRState *) opaque;
+
     zynq_slcr_compute_clocks(s);
     zynq_slcr_propagate_clocks(s);
 }
@@ -576,7 +577,7 @@ static const MemoryRegionOps slcr_ops = {
 };
 
 static const ClockPortInitArray zynq_slcr_clocks = {
-    QDEV_CLOCK_IN(ZynqSLCRState, ps_clk, zynq_slcr_ps_clk_callback),
+    QDEV_CLOCK_IN(ZynqSLCRState, ps_clk, zynq_slcr_ps_clk_callback, ClockUpdate),
     QDEV_CLOCK_OUT(ZynqSLCRState, uart0_ref_clk),
     QDEV_CLOCK_OUT(ZynqSLCRState, uart1_ref_clk),
     QDEV_CLOCK_END