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-rw-r--r--qemu/hw/misc/max111x.c214
1 files changed, 214 insertions, 0 deletions
diff --git a/qemu/hw/misc/max111x.c b/qemu/hw/misc/max111x.c
new file mode 100644
index 000000000..bef3651d6
--- /dev/null
+++ b/qemu/hw/misc/max111x.c
@@ -0,0 +1,214 @@
+/*
+ * Maxim MAX1110/1111 ADC chip emulation.
+ *
+ * Copyright (c) 2006 Openedhand Ltd.
+ * Written by Andrzej Zaborowski <balrog@zabor.org>
+ *
+ * This code is licensed under the GNU GPLv2.
+ *
+ * Contributions after 2012-01-13 are licensed under the terms of the
+ * GNU GPL, version 2 or (at your option) any later version.
+ */
+
+#include "hw/ssi.h"
+
+typedef struct {
+ SSISlave parent_obj;
+
+ qemu_irq interrupt;
+ uint8_t tb1, rb2, rb3;
+ int cycle;
+
+ uint8_t input[8];
+ int inputs, com;
+} MAX111xState;
+
+#define TYPE_MAX_111X "max111x"
+
+#define MAX_111X(obj) \
+ OBJECT_CHECK(MAX111xState, (obj), TYPE_MAX_111X)
+
+#define TYPE_MAX_1110 "max1110"
+#define TYPE_MAX_1111 "max1111"
+
+/* Control-byte bitfields */
+#define CB_PD0 (1 << 0)
+#define CB_PD1 (1 << 1)
+#define CB_SGL (1 << 2)
+#define CB_UNI (1 << 3)
+#define CB_SEL0 (1 << 4)
+#define CB_SEL1 (1 << 5)
+#define CB_SEL2 (1 << 6)
+#define CB_START (1 << 7)
+
+#define CHANNEL_NUM(v, b0, b1, b2) \
+ ((((v) >> (2 + (b0))) & 4) | \
+ (((v) >> (3 + (b1))) & 2) | \
+ (((v) >> (4 + (b2))) & 1))
+
+static uint32_t max111x_read(MAX111xState *s)
+{
+ if (!s->tb1)
+ return 0;
+
+ switch (s->cycle ++) {
+ case 1:
+ return s->rb2;
+ case 2:
+ return s->rb3;
+ }
+
+ return 0;
+}
+
+/* Interpret a control-byte */
+static void max111x_write(MAX111xState *s, uint32_t value)
+{
+ int measure, chan;
+
+ /* Ignore the value if START bit is zero */
+ if (!(value & CB_START))
+ return;
+
+ s->cycle = 0;
+
+ if (!(value & CB_PD1)) {
+ s->tb1 = 0;
+ return;
+ }
+
+ s->tb1 = value;
+
+ if (s->inputs == 8)
+ chan = CHANNEL_NUM(value, 1, 0, 2);
+ else
+ chan = CHANNEL_NUM(value & ~CB_SEL0, 0, 1, 2);
+
+ if (value & CB_SGL)
+ measure = s->input[chan] - s->com;
+ else
+ measure = s->input[chan] - s->input[chan ^ 1];
+
+ if (!(value & CB_UNI))
+ measure ^= 0x80;
+
+ s->rb2 = (measure >> 2) & 0x3f;
+ s->rb3 = (measure << 6) & 0xc0;
+
+ /* FIXME: When should the IRQ be lowered? */
+ qemu_irq_raise(s->interrupt);
+}
+
+static uint32_t max111x_transfer(SSISlave *dev, uint32_t value)
+{
+ MAX111xState *s = MAX_111X(dev);
+ max111x_write(s, value);
+ return max111x_read(s);
+}
+
+static const VMStateDescription vmstate_max111x = {
+ .name = "max111x",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .fields = (VMStateField[]) {
+ VMSTATE_SSI_SLAVE(parent_obj, MAX111xState),
+ VMSTATE_UINT8(tb1, MAX111xState),
+ VMSTATE_UINT8(rb2, MAX111xState),
+ VMSTATE_UINT8(rb3, MAX111xState),
+ VMSTATE_INT32_EQUAL(inputs, MAX111xState),
+ VMSTATE_INT32(com, MAX111xState),
+ VMSTATE_ARRAY_INT32_UNSAFE(input, MAX111xState, inputs,
+ vmstate_info_uint8, uint8_t),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
+static int max111x_init(SSISlave *d, int inputs)
+{
+ DeviceState *dev = DEVICE(d);
+ MAX111xState *s = MAX_111X(dev);
+
+ qdev_init_gpio_out(dev, &s->interrupt, 1);
+
+ s->inputs = inputs;
+ /* TODO: add a user interface for setting these */
+ s->input[0] = 0xf0;
+ s->input[1] = 0xe0;
+ s->input[2] = 0xd0;
+ s->input[3] = 0xc0;
+ s->input[4] = 0xb0;
+ s->input[5] = 0xa0;
+ s->input[6] = 0x90;
+ s->input[7] = 0x80;
+ s->com = 0;
+
+ vmstate_register(dev, -1, &vmstate_max111x, s);
+ return 0;
+}
+
+static int max1110_init(SSISlave *dev)
+{
+ return max111x_init(dev, 8);
+}
+
+static int max1111_init(SSISlave *dev)
+{
+ return max111x_init(dev, 4);
+}
+
+void max111x_set_input(DeviceState *dev, int line, uint8_t value)
+{
+ MAX111xState *s = MAX_111X(dev);
+ assert(line >= 0 && line < s->inputs);
+ s->input[line] = value;
+}
+
+static void max111x_class_init(ObjectClass *klass, void *data)
+{
+ SSISlaveClass *k = SSI_SLAVE_CLASS(klass);
+
+ k->transfer = max111x_transfer;
+}
+
+static const TypeInfo max111x_info = {
+ .name = TYPE_MAX_111X,
+ .parent = TYPE_SSI_SLAVE,
+ .instance_size = sizeof(MAX111xState),
+ .class_init = max111x_class_init,
+ .abstract = true,
+};
+
+static void max1110_class_init(ObjectClass *klass, void *data)
+{
+ SSISlaveClass *k = SSI_SLAVE_CLASS(klass);
+
+ k->init = max1110_init;
+}
+
+static const TypeInfo max1110_info = {
+ .name = TYPE_MAX_1110,
+ .parent = TYPE_MAX_111X,
+ .class_init = max1110_class_init,
+};
+
+static void max1111_class_init(ObjectClass *klass, void *data)
+{
+ SSISlaveClass *k = SSI_SLAVE_CLASS(klass);
+
+ k->init = max1111_init;
+}
+
+static const TypeInfo max1111_info = {
+ .name = TYPE_MAX_1111,
+ .parent = TYPE_MAX_111X,
+ .class_init = max1111_class_init,
+};
+
+static void max111x_register_types(void)
+{
+ type_register_static(&max111x_info);
+ type_register_static(&max1110_info);
+ type_register_static(&max1111_info);
+}
+
+type_init(max111x_register_types)