[Qemu-devel] [PATCH 06/13] mxs/imx23: Add digctl driver

[Michel Pollet <buserror@gmail.com>]

This implements just enough of the digctl IO block to allow
linux to believe it's running on (currently only) an imx23.

Signed-off-by: Michel Pollet <buserror@gmail.com>
---
 hw/arm/Makefile.objs  |   1 +
 hw/arm/imx23_digctl.c | 110 ++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 111 insertions(+)
 create mode 100644 hw/arm/imx23_digctl.c

diff --git a/hw/arm/Makefile.objs b/hw/arm/Makefile.objs
index 78b5614..9adcb96 100644
--- a/hw/arm/Makefile.objs
+++ b/hw/arm/Makefile.objs
@@ -5,3 +5,4 @@ obj-y += tosa.o versatilepb.o vexpress.o virt.o xilinx_zynq.o z2.o
 
 obj-y += armv7m.o exynos4210.o pxa2xx.o pxa2xx_gpio.o pxa2xx_pic.o
 obj-y += omap1.o omap2.o strongarm.o
+obj-$(CONFIG_MXS) += imx23_digctl.o
diff --git a/hw/arm/imx23_digctl.c b/hw/arm/imx23_digctl.c
new file mode 100644
index 0000000..b7cd1ff
--- /dev/null
+++ b/hw/arm/imx23_digctl.c
@@ -0,0 +1,110 @@
+/*
+ * imx23_digctl.c
+ *
+ * Copyright: Michel Pollet <buserror@gmail.com>
+ *
+ * QEMU Licence
+ */
+
+/*
+ * This module implements a very basic IO block for the digctl of the imx23
+ * Basically there is no real logic, just constant registers return, the most
+ * used one bing the "chip id" that is used by the various linux drivers
+ * to differentiate between imx23 and 28.
+ *
+ * The module consists mostly of read/write registers that the bootloader and
+ * kernel are quite happy to 'set' to whatever value they believe they set...
+ */
+
+#include "hw/sysbus.h"
+#include "hw/arm/mxs.h"
+
+enum {
+    HW_DIGCTL_RAMCTL = 0x3,
+    HW_DIGCTL_CHIPID = 0x31,
+};
+
+typedef struct imx23_digctl_state {
+    SysBusDevice busdev;
+    MemoryRegion iomem;
+
+    uint32_t	reg[0x2000 / 4];
+} imx23_digctl_state;
+
+static uint64_t imx23_digctl_read(
+        void *opaque, hwaddr offset, unsigned size)
+{
+    imx23_digctl_state *s = (imx23_digctl_state *)opaque;
+    uint32_t res = 0;
+
+    switch (offset >> 4) {
+    	case 0 ... 0x2000/4:
+    		res = s->reg[offset >> 4];
+    		break;
+        default:
+	        qemu_log_mask(LOG_GUEST_ERROR,
+	        		"%s: bad offset 0x%x\n", __func__, (int)offset);
+        	return 0;
+    }
+    return res;
+}
+
+static void imx23_digctl_write(
+        void *opaque, hwaddr offset, uint64_t value, unsigned size)
+{
+    imx23_digctl_state *s = (imx23_digctl_state *) opaque;
+    uint32_t * dst = NULL;
+
+    switch (offset >> 4) {
+        case 0 ... 0x2000 / 4:
+            dst = &s->reg[(offset >> 4)];
+            break;
+        default:
+            qemu_log_mask(LOG_GUEST_ERROR,
+                    "%s: bad offset 0x%x\n", __func__, (int) offset);
+            return;
+    }
+    if (!dst) {
+        return;
+    }
+    mxs_write(dst, offset, value, size);
+}
+
+static const MemoryRegionOps imx23_digctl_ops = {
+    .read = imx23_digctl_read,
+    .write = imx23_digctl_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+};
+
+static int imx23_digctl_init(SysBusDevice *dev)
+{
+    imx23_digctl_state *s = OBJECT_CHECK(imx23_digctl_state, dev, "imx23_digctl");
+
+    memory_region_init_io(&s->iomem, OBJECT(s), &imx23_digctl_ops, s,
+            "imx23_digctl", 0x2000);
+    sysbus_init_mmio(dev, &s->iomem);
+    s->reg[HW_DIGCTL_RAMCTL] = 0x6d676953;  /* default reset value */
+    s->reg[HW_DIGCTL_CHIPID] = 0x37800000;  /* i.mX233 */
+    return 0;
+}
+
+static void imx23_digctl_class_init(ObjectClass *klass, void *data)
+{
+    SysBusDeviceClass *sdc = SYS_BUS_DEVICE_CLASS(klass);
+
+    sdc->init = imx23_digctl_init;
+}
+
+static TypeInfo digctl_info = {
+    .name          = "imx23_digctl",
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(imx23_digctl_state),
+    .class_init    = imx23_digctl_class_init,
+};
+
+static void imx23_digctl_register(void)
+{
+    type_register_static(&digctl_info);
+}
+
+type_init(imx23_digctl_register)
-- 
1.8.5.1