From: Conor Dooley <conor.dooley@microchip.com>

On PolarFire SoC, some peripherals (eg the PCI root port) are clocked by
"Clock Conditioning Circuitry" in the FPGA. The specific clock depends
on the FPGA bitstream & can be locked to one particular {D,P}LL - in the
Icicle Kit Reference Design v2022.09 or later this is/will be the case.

Linux v6.1+ will have a driver for this peripheral and devicetrees that
previously relied on "fixed-frequency" clock nodes have been switched
over to clock-controller nodes. The IOSCB region is represented in QEMU,
but the specific region of it that the CCCs occupy has not so v6.1-rcN
kernels fail to boot in QEMU.

Add the regions as unimplemented so that the status-quo in terms of boot
is maintained.

Acked-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Message-Id: <20221117225518.4102575-2-conor@kernel.org>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 include/hw/misc/mchp_pfsoc_ioscb.h | 1 +
 hw/misc/mchp_pfsoc_ioscb.c         | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/include/hw/misc/mchp_pfsoc_ioscb.h b/include/hw/misc/mchp_pfsoc_ioscb.h
index 9235523e33..687b213742 100644
--- a/include/hw/misc/mchp_pfsoc_ioscb.h
+++ b/include/hw/misc/mchp_pfsoc_ioscb.h
@@ -30,6 +30,7 @@ typedef struct MchpPfSoCIoscbState {
     MemoryRegion lane23;
     MemoryRegion ctrl;
     MemoryRegion cfg;
+    MemoryRegion ccc;
     MemoryRegion pll_mss;
     MemoryRegion cfm_mss;
     MemoryRegion pll_ddr;
diff --git a/hw/misc/mchp_pfsoc_ioscb.c b/hw/misc/mchp_pfsoc_ioscb.c
index f4fd55a0e5..f976e42f72 100644
--- a/hw/misc/mchp_pfsoc_ioscb.c
+++ b/hw/misc/mchp_pfsoc_ioscb.c
@@ -33,6 +33,7 @@
  */
 #define IOSCB_WHOLE_REG_SIZE        0x10000000
 #define IOSCB_SUBMOD_REG_SIZE       0x1000
+#define IOSCB_CCC_REG_SIZE          0x2000000
 
 /*
  * There are many sub-modules in the IOSCB module.
@@ -45,6 +46,7 @@
 #define IOSCB_LANE23_BASE           0x06510000
 #define IOSCB_CTRL_BASE             0x07020000
 #define IOSCB_CFG_BASE              0x07080000
+#define IOSCB_CCC_BASE              0x08000000
 #define IOSCB_PLL_MSS_BASE          0x0E001000
 #define IOSCB_CFM_MSS_BASE          0x0E002000
 #define IOSCB_PLL_DDR_BASE          0x0E010000
@@ -168,6 +170,10 @@ static void mchp_pfsoc_ioscb_realize(DeviceState *dev, Error **errp)
                           "mchp.pfsoc.ioscb.cfg", IOSCB_SUBMOD_REG_SIZE);
     memory_region_add_subregion(&s->container, IOSCB_CFG_BASE, &s->cfg);
 
+    memory_region_init_io(&s->ccc, OBJECT(s), &mchp_pfsoc_dummy_ops, s,
+                          "mchp.pfsoc.ioscb.ccc", IOSCB_CCC_REG_SIZE);
+    memory_region_add_subregion(&s->container, IOSCB_CCC_BASE, &s->ccc);
+
     memory_region_init_io(&s->pll_mss, OBJECT(s), &mchp_pfsoc_pll_ops, s,
                           "mchp.pfsoc.ioscb.pll_mss", IOSCB_SUBMOD_REG_SIZE);
     memory_region_add_subregion(&s->container, IOSCB_PLL_MSS_BASE, &s->pll_mss);
-- 
2.38.1