hw/misc/bcm2835_cprman: add a PLL skeleton implementation

There are 5 PLLs in the CPRMAN, namely PLL A, C, D, H and B. All of them
take the xosc clock as input and produce a new clock.

This commit adds a skeleton implementation for the PLLs as sub-devices
of the CPRMAN. The PLLs are instantiated and connected internally to the
main oscillator.

Each PLL has 6 registers : CM, A2W_CTRL, A2W_ANA[0,1,2,3], A2W_FRAC. A
write to any of them triggers a call to the (not yet implemented)
pll_update function.

If the main oscillator changes frequency, an update is also triggered.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Luc Michel <luc@lmichel.fr>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 108 insertions, 0 deletions

diff --git a/hw/misc/bcm2835_cprman.c b/hw/misc/bcm2835_cprman.c
index 57ab991..b86f590 100644
--- a/hw/misc/bcm2835_cprman.c
+++ b/hw/misc/bcm2835_cprman.c
@@ -48,6 +48,52 @@
 #include "hw/misc/bcm2835_cprman_internals.h"
 #include "trace.h"
 
+/* PLL */
+
+static void pll_update(CprmanPllState *pll)
+{
+    clock_update(pll->out, 0);
+}
+
+static void pll_xosc_update(void *opaque)
+{
+    pll_update(CPRMAN_PLL(opaque));
+}
+
+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->out = qdev_init_clock_out(DEVICE(s), "out");
+}
+
+static const VMStateDescription pll_vmstate = {
+    .name = TYPE_CPRMAN_PLL,
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_CLOCK(xosc_in, CprmanPllState),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void pll_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->vmsd = &pll_vmstate;
+}
+
+static const TypeInfo cprman_pll_info = {
+    .name = TYPE_CPRMAN_PLL,
+    .parent = TYPE_DEVICE,
+    .instance_size = sizeof(CprmanPllState),
+    .class_init = pll_class_init,
+    .instance_init = pll_init,
+};
+
+
 /* CPRMAN "top level" model */
 
 static uint64_t cprman_read(void *opaque, hwaddr offset,
@@ -66,6 +112,15 @@ static uint64_t cprman_read(void *opaque, hwaddr offset,
     return r;
 }
 
+#define CASE_PLL_REGS(pll_)       \
+    case R_CM_ ## pll_:           \
+    case R_A2W_ ## pll_ ## _CTRL: \
+    case R_A2W_ ## pll_ ## _ANA0: \
+    case R_A2W_ ## pll_ ## _ANA1: \
+    case R_A2W_ ## pll_ ## _ANA2: \
+    case R_A2W_ ## pll_ ## _ANA3: \
+    case R_A2W_ ## pll_ ## _FRAC
+
 static void cprman_write(void *opaque, hwaddr offset,
                          uint64_t value, unsigned size)
 {
@@ -82,8 +137,31 @@ static void cprman_write(void *opaque, hwaddr offset,
     trace_bcm2835_cprman_write(offset, value);
     s->regs[idx] = value;
 
+    switch (idx) {
+    CASE_PLL_REGS(PLLA) :
+        pll_update(&s->plls[CPRMAN_PLLA]);
+        break;
+
+    CASE_PLL_REGS(PLLC) :
+        pll_update(&s->plls[CPRMAN_PLLC]);
+        break;
+
+    CASE_PLL_REGS(PLLD) :
+        pll_update(&s->plls[CPRMAN_PLLD]);
+        break;
+
+    CASE_PLL_REGS(PLLH) :
+        pll_update(&s->plls[CPRMAN_PLLH]);
+        break;
+
+    CASE_PLL_REGS(PLLB) :
+        pll_update(&s->plls[CPRMAN_PLLB]);
+        break;
+    }
 }
 
+#undef CASE_PLL_REGS
+
 static const MemoryRegionOps cprman_ops = {
     .read = cprman_read,
     .write = cprman_write,
@@ -106,15 +184,27 @@ static const MemoryRegionOps cprman_ops = {
 static void cprman_reset(DeviceState *dev)
 {
     BCM2835CprmanState *s = CPRMAN(dev);
+    size_t i;
 
     memset(s->regs, 0, sizeof(s->regs));
 
+    for (i = 0; i < CPRMAN_NUM_PLL; i++) {
+        device_cold_reset(DEVICE(&s->plls[i]));
+    }
+
     clock_update_hz(s->xosc, s->xosc_freq);
 }
 
 static void cprman_init(Object *obj)
 {
     BCM2835CprmanState *s = CPRMAN(obj);
+    size_t i;
+
+    for (i = 0; i < CPRMAN_NUM_PLL; i++) {
+        object_initialize_child(obj, PLL_INIT_INFO[i].name,
+                                &s->plls[i], TYPE_CPRMAN_PLL);
+        set_pll_init_info(s, &s->plls[i], i);
+    }
 
     s->xosc = clock_new(obj, "xosc");
 
@@ -123,6 +213,22 @@ static void cprman_init(Object *obj)
     sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->iomem);
 }
 
+static void cprman_realize(DeviceState *dev, Error **errp)
+{
+    BCM2835CprmanState *s = CPRMAN(dev);
+    size_t i;
+
+    for (i = 0; i < CPRMAN_NUM_PLL; i++) {
+        CprmanPllState *pll = &s->plls[i];
+
+        clock_set_source(pll->xosc_in, s->xosc);
+
+        if (!qdev_realize(DEVICE(pll), NULL, errp)) {
+            return;
+        }
+    }
+}
+
 static const VMStateDescription cprman_vmstate = {
     .name = TYPE_BCM2835_CPRMAN,
     .version_id = 1,
@@ -142,6 +248,7 @@ static void cprman_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
 
+    dc->realize = cprman_realize;
     dc->reset = cprman_reset;
     dc->vmsd = &cprman_vmstate;
     device_class_set_props(dc, cprman_properties);
@@ -158,6 +265,7 @@ static const TypeInfo cprman_info = {
 static void cprman_register_types(void)
 {
     type_register_static(&cprman_info);
+    type_register_static(&cprman_pll_info);
 }
 
 type_init(cprman_register_types);