lm32: add Milkymist VGAFB support

This patch adds support for Milkymist's VGA framebuffer.

Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>

4 files changed, 398 insertions, 0 deletions

diff --git a/Makefile.target b/Makefile.target
index c009117e47..2a65e15be9 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -276,6 +276,8 @@ obj-lm32-y += milkymist-softusb.o
 obj-lm32-y += milkymist-sysctl.o
 obj-lm32-$(CONFIG_OPENGL) += milkymist-tmu2.o
 obj-lm32-y += milkymist-uart.o
+obj-lm32-y += milkymist-vgafb.o
+obj-lm32-y += framebuffer.o
 
 obj-mips-y = mips_r4k.o mips_jazz.o mips_malta.o mips_mipssim.o
 obj-mips-y += mips_addr.o mips_timer.o mips_int.o
diff --git a/hw/milkymist-vgafb.c b/hw/milkymist-vgafb.c
new file mode 100644
index 0000000000..8922731511
--- /dev/null
+++ b/hw/milkymist-vgafb.c
@@ -0,0 +1,318 @@
+
+/*
+ *  QEMU model of the Milkymist VGA framebuffer.
+ *
+ *  Copyright (c) 2010 Michael Walle <michael@walle.cc>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ *
+ * Specification available at:
+ *   http://www.milkymist.org/socdoc/vgafb.pdf
+ */
+
+#include "hw.h"
+#include "sysbus.h"
+#include "trace.h"
+#include "console.h"
+#include "framebuffer.h"
+#include "pixel_ops.h"
+#include "qemu-error.h"
+
+#define BITS 8
+#include "milkymist-vgafb_template.h"
+#define BITS 15
+#include "milkymist-vgafb_template.h"
+#define BITS 16
+#include "milkymist-vgafb_template.h"
+#define BITS 24
+#include "milkymist-vgafb_template.h"
+#define BITS 32
+#include "milkymist-vgafb_template.h"
+
+enum {
+    R_CTRL = 0,
+    R_HRES,
+    R_HSYNC_START,
+    R_HSYNC_END,
+    R_HSCAN,
+    R_VRES,
+    R_VSYNC_START,
+    R_VSYNC_END,
+    R_VSCAN,
+    R_BASEADDRESS,
+    R_BASEADDRESS_ACT,
+    R_BURST_COUNT,
+    R_SOURCE_CLOCK,
+    R_MAX
+};
+
+enum {
+    CTRL_RESET = (1<<0),
+};
+
+struct MilkymistVgafbState {
+    SysBusDevice busdev;
+    DisplayState *ds;
+
+    int invalidate;
+    uint32_t fb_offset;
+    uint32_t fb_mask;
+
+    uint32_t regs[R_MAX];
+};
+typedef struct MilkymistVgafbState MilkymistVgafbState;
+
+static int vgafb_enabled(MilkymistVgafbState *s)
+{
+    return !(s->regs[R_CTRL] & CTRL_RESET);
+}
+
+static void vgafb_update_display(void *opaque)
+{
+    MilkymistVgafbState *s = opaque;
+    int first = 0;
+    int last = 0;
+    drawfn fn;
+
+    if (!vgafb_enabled(s)) {
+        return;
+    }
+
+    int dest_width = s->regs[R_HRES];
+
+    switch (ds_get_bits_per_pixel(s->ds)) {
+    case 0:
+        return;
+    case 8:
+        fn = draw_line_8;
+        break;
+    case 15:
+        fn = draw_line_15;
+        dest_width *= 2;
+        break;
+    case 16:
+        fn = draw_line_16;
+        dest_width *= 2;
+        break;
+    case 24:
+        fn = draw_line_24;
+        dest_width *= 3;
+        break;
+    case 32:
+        fn = draw_line_32;
+        dest_width *= 4;
+        break;
+    default:
+        hw_error("milkymist_vgafb: bad color depth\n");
+        break;
+    }
+
+    framebuffer_update_display(s->ds,
+                               s->regs[R_BASEADDRESS] + s->fb_offset,
+                               s->regs[R_HRES],
+                               s->regs[R_VRES],
+                               s->regs[R_HRES] * 2,
+                               dest_width,
+                               0,
+                               s->invalidate,
+                               fn,
+                               NULL,
+                               &first, &last);
+
+    if (first >= 0) {
+        dpy_update(s->ds, 0, first, s->regs[R_HRES], last - first + 1);
+    }
+    s->invalidate = 0;
+}
+
+static void vgafb_invalidate_display(void *opaque)
+{
+    MilkymistVgafbState *s = opaque;
+    s->invalidate = 1;
+}
+
+static void vgafb_resize(MilkymistVgafbState *s)
+{
+    if (!vgafb_enabled(s)) {
+        return;
+    }
+
+    qemu_console_resize(s->ds, s->regs[R_HRES], s->regs[R_VRES]);
+    s->invalidate = 1;
+}
+
+static uint32_t vgafb_read(void *opaque, target_phys_addr_t addr)
+{
+    MilkymistVgafbState *s = opaque;
+    uint32_t r = 0;
+
+    addr >>= 2;
+    switch (addr) {
+    case R_CTRL:
+    case R_HRES:
+    case R_HSYNC_START:
+    case R_HSYNC_END:
+    case R_HSCAN:
+    case R_VRES:
+    case R_VSYNC_START:
+    case R_VSYNC_END:
+    case R_VSCAN:
+    case R_BASEADDRESS:
+    case R_BURST_COUNT:
+    case R_SOURCE_CLOCK:
+        r = s->regs[addr];
+    break;
+    case R_BASEADDRESS_ACT:
+        r = s->regs[R_BASEADDRESS];
+    break;
+
+    default:
+        error_report("milkymist_vgafb: read access to unknown register 0x"
+                TARGET_FMT_plx, addr << 2);
+        break;
+    }
+
+    trace_milkymist_vgafb_memory_read(addr << 2, r);
+
+    return r;
+}
+
+static void
+vgafb_write(void *opaque, target_phys_addr_t addr, uint32_t value)
+{
+    MilkymistVgafbState *s = opaque;
+
+    trace_milkymist_vgafb_memory_write(addr, value);
+
+    addr >>= 2;
+    switch (addr) {
+    case R_CTRL:
+    case R_HSYNC_START:
+    case R_HSYNC_END:
+    case R_HSCAN:
+    case R_VSYNC_START:
+    case R_VSYNC_END:
+    case R_VSCAN:
+    case R_BURST_COUNT:
+    case R_SOURCE_CLOCK:
+        s->regs[addr] = value;
+        break;
+    case R_BASEADDRESS:
+        if (value & 0x1f) {
+            error_report("milkymist_vgafb: framebuffer base address have to "
+                     "be 32 byte aligned");
+            break;
+        }
+        s->regs[addr] = value & s->fb_mask;
+        s->invalidate = 1;
+        break;
+    case R_HRES:
+    case R_VRES:
+        s->regs[addr] = value;
+        vgafb_resize(s);
+        break;
+    case R_BASEADDRESS_ACT:
+        error_report("milkymist_vgafb: write to read-only register 0x"
+                TARGET_FMT_plx, addr << 2);
+        break;
+
+    default:
+        error_report("milkymist_vgafb: write access to unknown register 0x"
+                TARGET_FMT_plx, addr << 2);
+        break;
+    }
+}
+
+static CPUReadMemoryFunc * const vgafb_read_fn[] = {
+   NULL,
+   NULL,
+   &vgafb_read
+};
+
+static CPUWriteMemoryFunc * const vgafb_write_fn[] = {
+   NULL,
+   NULL,
+   &vgafb_write
+};
+
+static void milkymist_vgafb_reset(DeviceState *d)
+{
+    MilkymistVgafbState *s = container_of(d, MilkymistVgafbState, busdev.qdev);
+    int i;
+
+    for (i = 0; i < R_MAX; i++) {
+        s->regs[i] = 0;
+    }
+
+    /* defaults */
+    s->regs[R_CTRL] = CTRL_RESET;
+    s->regs[R_HRES] = 640;
+    s->regs[R_VRES] = 480;
+    s->regs[R_BASEADDRESS] = 0;
+}
+
+static int milkymist_vgafb_init(SysBusDevice *dev)
+{
+    MilkymistVgafbState *s = FROM_SYSBUS(typeof(*s), dev);
+    int vgafb_regs;
+
+    vgafb_regs = cpu_register_io_memory(vgafb_read_fn, vgafb_write_fn, s,
+            DEVICE_NATIVE_ENDIAN);
+    sysbus_init_mmio(dev, R_MAX * 4, vgafb_regs);
+
+    s->ds = graphic_console_init(vgafb_update_display,
+                                 vgafb_invalidate_display,
+                                 NULL, NULL, s);
+
+    return 0;
+}
+
+static int vgafb_post_load(void *opaque, int version_id)
+{
+    vgafb_invalidate_display(opaque);
+    return 0;
+}
+
+static const VMStateDescription vmstate_milkymist_vgafb = {
+    .name = "milkymist-vgafb",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .minimum_version_id_old = 1,
+    .post_load = vgafb_post_load,
+    .fields      = (VMStateField[]) {
+        VMSTATE_UINT32_ARRAY(regs, MilkymistVgafbState, R_MAX),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static SysBusDeviceInfo milkymist_vgafb_info = {
+    .init = milkymist_vgafb_init,
+    .qdev.name  = "milkymist-vgafb",
+    .qdev.size  = sizeof(MilkymistVgafbState),
+    .qdev.vmsd  = &vmstate_milkymist_vgafb,
+    .qdev.reset = milkymist_vgafb_reset,
+    .qdev.props = (Property[]) {
+        DEFINE_PROP_UINT32("fb_offset", MilkymistVgafbState, fb_offset, 0x0),
+        DEFINE_PROP_UINT32("fb_mask", MilkymistVgafbState, fb_mask, 0xffffffff),
+        DEFINE_PROP_END_OF_LIST(),
+    }
+};
+
+static void milkymist_vgafb_register(void)
+{
+    sysbus_register_withprop(&milkymist_vgafb_info);
+}
+
+device_init(milkymist_vgafb_register)
diff --git a/hw/milkymist-vgafb_template.h b/hw/milkymist-vgafb_template.h
new file mode 100644
index 0000000000..69af9ef3f6
--- /dev/null
+++ b/hw/milkymist-vgafb_template.h
@@ -0,0 +1,74 @@
+/*
+ *  QEMU model of the Milkymist VGA framebuffer.
+ *
+ *  Copyright (c) 2010 Michael Walle <michael@walle.cc>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#if BITS == 8
+#define COPY_PIXEL(to, r, g, b)                    \
+    do {                                           \
+        *to = rgb_to_pixel8(r, g, b);              \
+        to += 1;                                   \
+    } while (0)
+#elif BITS == 15
+#define COPY_PIXEL(to, r, g, b)                    \
+    do {                                           \
+        *(uint16_t *)to = rgb_to_pixel15(r, g, b); \
+        to += 2;                                   \
+    } while (0)
+#elif BITS == 16
+#define COPY_PIXEL(to, r, g, b)                    \
+    do {                                           \
+        *(uint16_t *)to = rgb_to_pixel16(r, g, b); \
+        to += 2;                                   \
+    } while (0)
+#elif BITS == 24
+#define COPY_PIXEL(to, r, g, b)                    \
+    do {                                           \
+        uint32 tmp = rgb_to_pixel24(r, g, b);      \
+        *(to++) =         tmp & 0xff;              \
+        *(to++) =  (tmp >> 8) & 0xff;              \
+        *(to++) = (tmp >> 16) & 0xff;              \
+    } while (0)
+#elif BITS == 32
+#define COPY_PIXEL(to, r, g, b)                    \
+    do {                                           \
+        *(uint32_t *)to = rgb_to_pixel32(r, g, b); \
+        to += 4;                                   \
+    } while (0)
+#else
+#error unknown bit depth
+#endif
+
+static void glue(draw_line_, BITS)(void *opaque, uint8_t *d, const uint8_t *s,
+        int width, int deststep)
+{
+    uint16_t rgb565;
+    uint8_t r, g, b;
+
+    while (width--) {
+        rgb565 = lduw_raw(s);
+        r = ((rgb565 >> 11) & 0x1f) << 3;
+        g = ((rgb565 >>  5) & 0x3f) << 2;
+        b = ((rgb565 >>  0) & 0x1f) << 3;
+        COPY_PIXEL(d, r, g, b);
+        s += 2;
+    }
+}
+
+#undef BITS
+#undef COPY_PIXEL
diff --git a/trace-events b/trace-events
index 55f3de532a..06efdb7753 100644
--- a/trace-events
+++ b/trace-events
@@ -355,3 +355,7 @@ disable milkymist_uart_memory_read(uint32_t addr, uint32_t value) "addr %08x val
 disable milkymist_uart_memory_write(uint32_t addr, uint32_t value) "addr %08x value %08x"
 disable milkymist_uart_pulse_irq_rx(void) "Pulse IRQ RX"
 disable milkymist_uart_pulse_irq_tx(void) "Pulse IRQ TX"
+
+# hw/milkymist-vgafb.c
+disable milkymist_vgafb_memory_read(uint32_t addr, uint32_t value) "addr %08x value %08x"
+disable milkymist_vgafb_memory_write(uint32_t addr, uint32_t value) "addr %08x value %08x"