/* * 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. */ #include "ssi.h" typedef struct { SSISlave ssidev; qemu_irq interrupt; uint8_t tb1, rb2, rb3; int cycle; uint8_t input[8]; int inputs, com; } MAX111xState; /* 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 = FROM_SSI_SLAVE(MAX111xState, dev); max111x_write(s, value); return max111x_read(s); } static const VMStateDescription vmstate_max111x = { .name = "max111x", .version_id = 0, .minimum_version_id = 0, .minimum_version_id_old = 0, .fields = (VMStateField[]) { 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 *dev, int inputs) { MAX111xState *s = FROM_SSI_SLAVE(MAX111xState, dev); qdev_init_gpio_out(&dev->qdev, &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->qdev, -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 = FROM_SSI_SLAVE(MAX111xState, SSI_SLAVE_FROM_QDEV(dev)); assert(line >= 0 && line < s->inputs); s->input[line] = value; } static SSISlaveInfo max1110_info = { .qdev.name = "max1110", .qdev.size = sizeof(MAX111xState), .init = max1110_init, .transfer = max111x_transfer }; static SSISlaveInfo max1111_info = { .qdev.name = "max1111", .qdev.size = sizeof(MAX111xState), .init = max1111_init, .transfer = max111x_transfer }; static void max111x_register_devices(void) { ssi_register_slave(&max1110_info); ssi_register_slave(&max1111_info); } device_init(max111x_register_devices)