hw/misc/bcm2835_cprman: add the DSI0HSCK multiplexer

This simple mux sits between the PLL channels and the DSI0E and DSI0P
clock muxes. This mux selects between PLLA-DSI0 and PLLD-DSI0 channel
and outputs the selected signal to source number 4 of DSI0E/P clock
muxes. It is controlled by the cm_dsi0hsck register.

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>

hw/misc/bcm2835_cprman.c

@@ -339,6 +339,58 @@ static const TypeInfo cprman_clock_mux_info = {
 };
 
 
+/* DSI0HSCK mux */
+
+static void dsi0hsck_mux_update(CprmanDsi0HsckMuxState *s)
+{
+    bool src_is_plld = FIELD_EX32(*s->reg_cm, CM_DSI0HSCK, SELPLLD);
+    Clock *src = src_is_plld ? s->plld_in : s->plla_in;
+
+    clock_update(s->out, clock_get(src));
+}
+
+static void dsi0hsck_mux_in_update(void *opaque)
+{
+    dsi0hsck_mux_update(CPRMAN_DSI0HSCK_MUX(opaque));
+}
+
+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->out = qdev_init_clock_out(DEVICE(s), "out");
+}
+
+static const VMStateDescription dsi0hsck_mux_vmstate = {
+    .name = TYPE_CPRMAN_DSI0HSCK_MUX,
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_CLOCK(plla_in, CprmanDsi0HsckMuxState),
+        VMSTATE_CLOCK(plld_in, CprmanDsi0HsckMuxState),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void dsi0hsck_mux_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->vmsd = &dsi0hsck_mux_vmstate;
+}
+
+static const TypeInfo cprman_dsi0hsck_mux_info = {
+    .name = TYPE_CPRMAN_DSI0HSCK_MUX,
+    .parent = TYPE_DEVICE,
+    .instance_size = sizeof(CprmanDsi0HsckMuxState),
+    .class_init = dsi0hsck_mux_class_init,
+    .instance_init = dsi0hsck_mux_init,
+};
+
+
 /* CPRMAN "top level" model */
 
 static uint32_t get_cm_lock(const BCM2835CprmanState *s)
@@ -501,6 +553,10 @@ static void cprman_write(void *opaque, hwaddr offset,
     case R_CM_EMMC2CTL ... R_CM_EMMC2DIV:
         update_mux_from_cm(s, idx);
         break;
+
+    case R_CM_DSI0HSCK:
+        dsi0hsck_mux_update(&s->dsi0hsck_mux);
+        break;
     }
 }
 
@@ -540,6 +596,8 @@ static void cprman_reset(DeviceState *dev)
         device_cold_reset(DEVICE(&s->channels[i]));
     }
 
+    device_cold_reset(DEVICE(&s->dsi0hsck_mux));
+
     for (i = 0; i < CPRMAN_NUM_CLOCK_MUX; i++) {
         device_cold_reset(DEVICE(&s->clock_muxes[i]));
     }
@@ -565,6 +623,10 @@ static void cprman_init(Object *obj)
         set_pll_channel_init_info(s, &s->channels[i], i);
     }
 
+    object_initialize_child(obj, "dsi0hsck-mux",
+                            &s->dsi0hsck_mux, TYPE_CPRMAN_DSI0HSCK_MUX);
+    s->dsi0hsck_mux.reg_cm = &s->regs[R_CM_DSI0HSCK];
+
     for (i = 0; i < CPRMAN_NUM_CLOCK_MUX; i++) {
         char *alias;
 
@@ -612,7 +674,7 @@ static void connect_mux_sources(BCM2835CprmanState *s,
         if (mapping == CPRMAN_CLOCK_SRC_FORCE_GROUND) {
             src = s->gnd;
         } else if (mapping == CPRMAN_CLOCK_SRC_DSI0HSCK) {
-            src = s->gnd; /* TODO */
+            src = s->dsi0hsck_mux.out;
         } else if (i < CPRMAN_CLOCK_SRC_PLLA) {
             src = CLK_SRC_MAPPING[i];
         } else {
@@ -650,6 +712,15 @@ static void cprman_realize(DeviceState *dev, Error **errp)
         }
     }
 
+    clock_set_source(s->dsi0hsck_mux.plla_in,
+                     s->channels[CPRMAN_PLLA_CHANNEL_DSI0].out);
+    clock_set_source(s->dsi0hsck_mux.plld_in,
+                     s->channels[CPRMAN_PLLD_CHANNEL_DSI0].out);
+
+    if (!qdev_realize(DEVICE(&s->dsi0hsck_mux), NULL, errp)) {
+        return;
+    }
+
     for (i = 0; i < CPRMAN_NUM_CLOCK_MUX; i++) {
         CprmanClockMuxState *clock_mux = &s->clock_muxes[i];
 
@@ -700,6 +771,7 @@ static void cprman_register_types(void)
     type_register_static(&cprman_pll_info);
     type_register_static(&cprman_pll_channel_info);
     type_register_static(&cprman_clock_mux_info);
+    type_register_static(&cprman_dsi0hsck_mux_info);
 }
 
 type_init(cprman_register_types);

include/hw/misc/bcm2835_cprman.h

@@ -174,6 +174,20 @@ typedef struct CprmanClockMuxState {
     struct CprmanClockMuxState *backref[CPRMAN_NUM_CLOCK_MUX_SRC];
 } CprmanClockMuxState;
 
+typedef struct CprmanDsi0HsckMuxState {
+    /*< private >*/
+    DeviceState parent_obj;
+
+    /*< public >*/
+    CprmanClockMux id;
+
+    uint32_t *reg_cm;
+
+    Clock *plla_in;
+    Clock *plld_in;
+    Clock *out;
+} CprmanDsi0HsckMuxState;
+
 struct BCM2835CprmanState {
     /*< private >*/
     SysBusDevice parent_obj;
@@ -184,6 +198,7 @@ struct BCM2835CprmanState {
     CprmanPllState plls[CPRMAN_NUM_PLL];
     CprmanPllChannelState channels[CPRMAN_NUM_PLL_CHANNEL];
     CprmanClockMuxState clock_muxes[CPRMAN_NUM_CLOCK_MUX];
+    CprmanDsi0HsckMuxState dsi0hsck_mux;
 
     uint32_t regs[CPRMAN_NUM_REGS];
     uint32_t xosc_freq;

include/hw/misc/bcm2835_cprman_internals.h

@@ -15,6 +15,7 @@
 #define TYPE_CPRMAN_PLL "bcm2835-cprman-pll"
 #define TYPE_CPRMAN_PLL_CHANNEL "bcm2835-cprman-pll-channel"
 #define TYPE_CPRMAN_CLOCK_MUX "bcm2835-cprman-clock-mux"
+#define TYPE_CPRMAN_DSI0HSCK_MUX "bcm2835-cprman-dsi0hsck-mux"
 
 DECLARE_INSTANCE_CHECKER(CprmanPllState, CPRMAN_PLL,
                          TYPE_CPRMAN_PLL)
@@ -22,6 +23,8 @@ DECLARE_INSTANCE_CHECKER(CprmanPllChannelState, CPRMAN_PLL_CHANNEL,
                          TYPE_CPRMAN_PLL_CHANNEL)
 DECLARE_INSTANCE_CHECKER(CprmanClockMuxState, CPRMAN_CLOCK_MUX,
                          TYPE_CPRMAN_CLOCK_MUX)
+DECLARE_INSTANCE_CHECKER(CprmanDsi0HsckMuxState, CPRMAN_DSI0HSCK_MUX,
+                         TYPE_CPRMAN_DSI0HSCK_MUX)
 
 /* Register map */
 
@@ -223,6 +226,9 @@ REG32(CM_LOCK, 0x114)
     FIELD(CM_LOCK, FLOCKB, 9, 1)
     FIELD(CM_LOCK, FLOCKA, 8, 1)
 
+REG32(CM_DSI0HSCK, 0x120)
+    FIELD(CM_DSI0HSCK, SELPLLD, 0, 1)
+
 /*
  * This field is common to all registers. Each register write value must match
  * the CPRMAN_PASSWORD magic value in its 8 MSB.