diff options
Diffstat (limited to 'src/hw/misc/max111x.c')
| -rw-r--r-- | src/hw/misc/max111x.c | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/src/hw/misc/max111x.c b/src/hw/misc/max111x.c new file mode 100644 index 0000000..bef3651 --- /dev/null +++ b/src/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) |
