[Qemu-devel] [PATCH/RFC 5/5] hw/arm/sysbus-fdt: Enable rcar-gen3-gpio dynamic instantiation

[Geert Uytterhoeven <geert+renesas@glider.be>]

Allow the instantiation of a Renesas R-Car Gen3 GPIO controller device
from the QEMU command line:

-device vfio-platform,host=<device>,manufacturer=renesas,model=rcar-gen3-gpio
-device vfio-platform,sysfsdev=<path>,manufacturer=renesas,model=rcar-gen3-gpio

A specialized device tree node is created for the guest, containing
compatible, reg, gpio-controller, and #gpio-cells properties.

Not-Yet-Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
Question:
  - Why do we need the manufacturer=foo,model=bar syntax? Can't this
    just be extracted from the host DT?

TODO:
  - Copy properties from the host DT, as add_amd_xgbe_fdt_node() does,
  - Make this more generic?
---
 hw/arm/sysbus-fdt.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

diff --git a/hw/arm/sysbus-fdt.c b/hw/arm/sysbus-fdt.c
index c5d4fd5604c28118..428175f343d9f3b9 100644
--- a/hw/arm/sysbus-fdt.c
+++ b/hw/arm/sysbus-fdt.c
@@ -416,6 +416,52 @@ static int add_amd_xgbe_fdt_node(SysBusDevice *sbdev, void *opaque)
     return 0;
 }
 
+/**
+ * add_rcar_gpio_fdt_node
+ *
+ * Generates a simple node with following properties:
+ * compatible string, regs, #gpio-cells, gpio-controller
+ */
+static int add_rcar_gpio_fdt_node(SysBusDevice *sbdev, void *opaque)
+{
+    PlatformBusFDTData *data = opaque;
+    PlatformBusDevice *pbus = data->pbus;
+    void *fdt = data->fdt;
+    const char *parent_node = data->pbus_node_name;
+    int compat_str_len, i;
+    char *nodename;
+    uint32_t *reg_attr;
+    uint64_t mmio_base;
+    VFIOPlatformDevice *vdev = VFIO_PLATFORM_DEVICE(sbdev);
+    VFIODevice *vbasedev = &vdev->vbasedev;
+
+    mmio_base = platform_bus_get_mmio_addr(pbus, sbdev, 0);
+    nodename = g_strdup_printf("%s/%s@%" PRIx64, parent_node,
+                               vbasedev->name, mmio_base);
+    qemu_fdt_add_subnode(fdt, nodename);
+
+    compat_str_len = strlen(vdev->compat) + 1;
+    qemu_fdt_setprop(fdt, nodename, "compatible",
+                          vdev->compat, compat_str_len);
+
+    qemu_fdt_setprop(fdt, nodename, "gpio-controller", NULL, 0);
+    qemu_fdt_setprop_cells(fdt, nodename, "#gpio-cells", 2);
+
+    reg_attr = g_new(uint32_t, vbasedev->num_regions * 2);
+    for (i = 0; i < vbasedev->num_regions; i++) {
+        mmio_base = platform_bus_get_mmio_addr(pbus, sbdev, i);
+        reg_attr[2 * i] = cpu_to_be32(mmio_base);
+        reg_attr[2 * i + 1] = cpu_to_be32(
+                                memory_region_size(vdev->regions[i]->mem));
+    }
+    qemu_fdt_setprop(fdt, nodename, "reg", reg_attr,
+                     vbasedev->num_regions * 2 * sizeof(uint32_t));
+
+    g_free(reg_attr);
+    g_free(nodename);
+    return 0;
+}
+
 /* manufacturer/model matching */
 static bool vfio_platform_match(SysBusDevice *sbdev,
                                 const BindingEntry *entry)
@@ -454,6 +500,7 @@ static const BindingEntry bindings[] = {
     TYPE_BINDING(TYPE_VFIO_CALXEDA_XGMAC, add_calxeda_midway_xgmac_fdt_node),
     TYPE_BINDING(TYPE_VFIO_AMD_XGBE, add_amd_xgbe_fdt_node),
     VFIO_PLATFORM_BINDING("amd", "xgbe-seattle-v1a", add_amd_xgbe_fdt_node),
+    VFIO_PLATFORM_BINDING("renesas", "rcar-gen3-gpio", add_rcar_gpio_fdt_node),
 #endif
     TYPE_BINDING("", NULL), /* last element */
 };
-- 
2.7.4