[Qemu-devel] [RFC v2 2/4] Add AMBA devices support to VFIO

[Alvise Rigo <a.rigo@virtualopensystems.com>]

The impossibility to add more then one compatibility property to the
device tree node was not permitting to bind AMBA devices.
Now we can add an arbitrary number of compatibility property values divided by
the character ";".

If the compatibility string contains the substring "arm,primecell", a
clock property will be added to the device tree node in order to allow the AMBA
bus code to probe the device.

Signed-off-by: Alvise Rigo <a.rigo@virtualopensystems.com>
---
 hw/arm/virt.c | 39 ++++++++++++++++++++++++++++++++++-----
 1 file changed, 34 insertions(+), 5 deletions(-)

diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 1fb66ef..dadf5f0 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -344,6 +344,8 @@ static int vfio_init_func(QemuOpts *opts, void *opaque)
     size_t size;
     int i;
     uint32_t *irq_attr;
+    bool is_amba = false;
+    int compat_str_len;
 
     if (!driver) {
         qerror_report(QERR_MISSING_PARAMETER, "driver");
@@ -369,12 +371,31 @@ static int vfio_init_func(QemuOpts *opts, void *opaque)
 
         /*
          * process compatibility property string passed by end-user
-         * replaces / by ,
-         * currently a single property compatibility value is supported!
+         * replaces / by , and ; by NUL character
          */
         corrected_compat = g_strdup(*pcompat);
-        char *slash = strchr(corrected_compat, '/');
-        *slash = ',';
+        /*
+         * the total length of the string has to include also the last
+         * NUL char.
+         */
+        compat_str_len = strlen(corrected_compat) + 1;
+
+        char *str_ptr = corrected_compat;
+        while ((str_ptr = strchr(str_ptr, '/')) != NULL) {
+            *str_ptr = ',';
+        }
+
+        /* check if is an AMBA device */
+        str_ptr = corrected_compat;
+        if (strstr(str_ptr, "arm,primecell") != NULL) {
+            is_amba = true;
+        }
+
+        /* substitute ";" with the NUL char */
+        str_ptr = corrected_compat;
+        while ((str_ptr = strchr(str_ptr, ';')) != NULL) {
+            *str_ptr = '\0';
+        }
 
         sysbus_mmio_map(s, 0, vbi->avail_vfio_base);
 
@@ -383,11 +404,19 @@ static int vfio_init_func(QemuOpts *opts, void *opaque)
         qemu_fdt_add_subnode(vbi->fdt, nodename);
 
         qemu_fdt_setprop(vbi->fdt, nodename, "compatible",
-                             corrected_compat, strlen(corrected_compat));
+                             corrected_compat, compat_str_len);
 
         qemu_fdt_setprop_sized_cells(vbi->fdt, nodename,
                              "reg", 2, vbi->avail_vfio_base, 2, size);
 
+        if (is_amba) {
+            qemu_fdt_setprop_cells(vbi->fdt, nodename, "clocks",
+                                   vbi->clock_phandle);
+            char clock_names[] = "apb_pclk";
+            qemu_fdt_setprop(vbi->fdt, nodename, "clock-names", clock_names,
+                                                       sizeof(clock_names));
+        }
+
         irq_attr = g_malloc0(num_irqs*3*sizeof(uint32_t));
         for (i = 0; i < num_irqs; i++) {
             sysbus_connect_irq(s, i, vbi->pic[irq_start+i]);
-- 
1.9.1