From 43f7868da3c84c1c7eef89631ab0bf6dc194eedb Mon Sep 17 00:00:00 2001
From: Guenter Roeck <linux@roeck-us.net>
Date: Sat, 23 Jun 2018 14:18:05 -0700
Subject: [PATCH] sam460ex: Fix sam460ex device tree when booting the Linux
 kernel

sam460ex (or at least this emulation) does not support the "ibm,cpm" power
management. As a result, Linux crashes when trying to access it. Remove
its device tree node. Also, if/when we boot the Linux kernel directly,
serial port clock frequencies in the device tree file will be unset, and
serial port initialization will fail. Add valid frequency values to
the serial ports to be able to use it. Also set valid values for the other
clock nodes otherwise set by u-boot.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: BALATON Zoltan <balaton@eik.bme.hu>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 hw/ppc/sam460ex.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/hw/ppc/sam460ex.c b/hw/ppc/sam460ex.c
index bdc53d2603..33ea51816c 100644
--- a/hw/ppc/sam460ex.c
+++ b/hw/ppc/sam460ex.c
@@ -37,6 +37,8 @@
 #include "hw/i2c/smbus.h"
 #include "hw/usb/hcd-ehci.h"
 
+#include <libfdt.h>
+
 #define BINARY_DEVICE_TREE_FILE "canyonlands.dtb"
 #define UBOOT_FILENAME "u-boot-sam460-20100605.bin"
 /* to extract the official U-Boot bin from the updater: */
@@ -67,6 +69,10 @@
 */
 
 #define CPU_FREQ 1150000000
+#define PLB_FREQ 230000000
+#define OPB_FREQ 115000000
+#define EBC_FREQ 115000000
+#define UART_FREQ 11059200
 #define SDRAM_NR_BANKS 4
 
 /* FIXME: See u-boot.git 8ac41e, also fix in ppc440_uc.c */
@@ -255,6 +261,7 @@ static int sam460ex_load_device_tree(hwaddr addr,
     void *fdt;
     uint32_t tb_freq = CPU_FREQ;
     uint32_t clock_freq = CPU_FREQ;
+    int offset;
 
     filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, BINARY_DEVICE_TREE_FILE);
     if (!filename) {
@@ -308,6 +315,27 @@ static int sam460ex_load_device_tree(hwaddr addr,
     qemu_fdt_setprop_cell(fdt, "/cpus/cpu@0", "timebase-frequency",
                               tb_freq);
 
+    /* Remove cpm node if it exists (it is not emulated) */
+    offset = fdt_path_offset(fdt, "/cpm");
+    if (offset >= 0) {
+        fdt_nop_node(fdt, offset);
+    }
+
+    /* set serial port clocks */
+    offset = fdt_node_offset_by_compatible(fdt, -1, "ns16550");
+    while (offset >= 0) {
+        fdt_setprop_cell(fdt, offset, "clock-frequency", UART_FREQ);
+        offset = fdt_node_offset_by_compatible(fdt, offset, "ns16550");
+    }
+
+    /* some more clocks */
+    qemu_fdt_setprop_cell(fdt, "/plb", "clock-frequency",
+                              PLB_FREQ);
+    qemu_fdt_setprop_cell(fdt, "/plb/opb", "clock-frequency",
+                              OPB_FREQ);
+    qemu_fdt_setprop_cell(fdt, "/plb/opb/ebc", "clock-frequency",
+                              EBC_FREQ);
+
     rom_add_blob_fixed(BINARY_DEVICE_TREE_FILE, fdt, fdt_size, addr);
     g_free(fdt);
     ret = fdt_size;