hw/char/mcf_uart.c - qemu - Git at Google

 /*
  * ColdFire UART emulation.
  *
  * Copyright (c) 2007 CodeSourcery.
  *
  * This code is licensed under the GPL
  */

 #include "qemu/osdep.h"
 #include "hw/irq.h"
 #include "hw/sysbus.h"
 #include "qemu/module.h"
 #include "qapi/error.h"
 #include "hw/m68k/mcf.h"
 #include "hw/qdev-properties.h"
 #include "hw/qdev-properties-system.h"
 #include "chardev/char-fe.h"
 #include "qom/object.h"

 #define FIFO_DEPTH 4

 struct mcf_uart_state {
     SysBusDevice parent_obj;

     MemoryRegion iomem;
     uint8_t mr[2];
     uint8_t sr;
     uint8_t isr;
     uint8_t imr;
     uint8_t bg1;
     uint8_t bg2;
     uint8_t fifo[FIFO_DEPTH];
     uint8_t tb;
     int current_mr;
     int fifo_len;
     int tx_enabled;
     int rx_enabled;
     qemu_irq irq;
     CharBackend chr;
 };

 #define TYPE_MCF_UART "mcf-uart"
 OBJECT_DECLARE_SIMPLE_TYPE(mcf_uart_state, MCF_UART)

 /* UART Status Register bits.  */
 #define MCF_UART_RxRDY  0x01
 #define MCF_UART_FFULL  0x02
 #define MCF_UART_TxRDY  0x04
 #define MCF_UART_TxEMP  0x08
 #define MCF_UART_OE     0x10
 #define MCF_UART_PE     0x20
 #define MCF_UART_FE     0x40
 #define MCF_UART_RB     0x80

 /* Interrupt flags.  */
 #define MCF_UART_TxINT  0x01
 #define MCF_UART_RxINT  0x02
 #define MCF_UART_DBINT  0x04
 #define MCF_UART_COSINT 0x80

 /* UMR1 flags.  */
 #define MCF_UART_BC0    0x01
 #define MCF_UART_BC1    0x02
 #define MCF_UART_PT     0x04
 #define MCF_UART_PM0    0x08
 #define MCF_UART_PM1    0x10
 #define MCF_UART_ERR    0x20
 #define MCF_UART_RxIRQ  0x40
 #define MCF_UART_RxRTS  0x80

 static void mcf_uart_update(mcf_uart_state *s)
 {
     s->isr &= ~(MCF_UART_TxINT | MCF_UART_RxINT);
     if (s->sr & MCF_UART_TxRDY)
         s->isr |= MCF_UART_TxINT;
     if ((s->sr & ((s->mr[0] & MCF_UART_RxIRQ)
                   ? MCF_UART_FFULL : MCF_UART_RxRDY)) != 0)
         s->isr |= MCF_UART_RxINT;

     qemu_set_irq(s->irq, (s->isr & s->imr) != 0);
 }

 uint64_t mcf_uart_read(void *opaque, hwaddr addr,
                        unsigned size)
 {
     mcf_uart_state *s = (mcf_uart_state *)opaque;
     switch (addr & 0x3f) {
     case 0x00:
         return s->mr[s->current_mr];
     case 0x04:
         return s->sr;
     case 0x0c:
         {
             uint8_t val;
             int i;

             if (s->fifo_len == 0)
                 return 0;

             val = s->fifo[0];
             s->fifo_len--;
             for (i = 0; i < s->fifo_len; i++)
                 s->fifo[i] = s->fifo[i + 1];
             s->sr &= ~MCF_UART_FFULL;
             if (s->fifo_len == 0)
                 s->sr &= ~MCF_UART_RxRDY;
             mcf_uart_update(s);
             qemu_chr_fe_accept_input(&s->chr);
             return val;
         }
     case 0x10:
         /* TODO: Implement IPCR.  */
         return 0;
     case 0x14:
         return s->isr;
     case 0x18:
         return s->bg1;
     case 0x1c:
         return s->bg2;
     default:
         return 0;
     }
 }

 /* Update TxRDY flag and set data if present and enabled.  */
 static void mcf_uart_do_tx(mcf_uart_state *s)
 {
     if (s->tx_enabled && (s->sr & MCF_UART_TxEMP) == 0) {
         /* XXX this blocks entire thread. Rewrite to use
          * qemu_chr_fe_write and background I/O callbacks */
         qemu_chr_fe_write_all(&s->chr, (unsigned char *)&s->tb, 1);
         s->sr |= MCF_UART_TxEMP;
     }
     if (s->tx_enabled) {
         s->sr |= MCF_UART_TxRDY;
     } else {
         s->sr &= ~MCF_UART_TxRDY;
     }
 }

 static void mcf_do_command(mcf_uart_state *s, uint8_t cmd)
 {
     /* Misc command.  */
     switch ((cmd >> 4) & 7) {
     case 0: /* No-op.  */
         break;
     case 1: /* Reset mode register pointer.  */
         s->current_mr = 0;
         break;
     case 2: /* Reset receiver.  */
         s->rx_enabled = 0;
         s->fifo_len = 0;
         s->sr &= ~(MCF_UART_RxRDY | MCF_UART_FFULL);
         break;
     case 3: /* Reset transmitter.  */
         s->tx_enabled = 0;
         s->sr |= MCF_UART_TxEMP;
         s->sr &= ~MCF_UART_TxRDY;
         break;
     case 4: /* Reset error status.  */
         break;
     case 5: /* Reset break-change interrupt.  */
         s->isr &= ~MCF_UART_DBINT;
         break;
     case 6: /* Start break.  */
     case 7: /* Stop break.  */
         break;
     }

     /* Transmitter command.  */
     switch ((cmd >> 2) & 3) {
     case 0: /* No-op.  */
         break;
     case 1: /* Enable.  */
         s->tx_enabled = 1;
         mcf_uart_do_tx(s);
         break;
     case 2: /* Disable.  */
         s->tx_enabled = 0;
         mcf_uart_do_tx(s);
         break;
     case 3: /* Reserved.  */
         fprintf(stderr, "mcf_uart: Bad TX command\n");
         break;
     }

     /* Receiver command.  */
     switch (cmd & 3) {
     case 0: /* No-op.  */
         break;
     case 1: /* Enable.  */
         s->rx_enabled = 1;
         break;
     case 2:
         s->rx_enabled = 0;
         break;
     case 3: /* Reserved.  */
         fprintf(stderr, "mcf_uart: Bad RX command\n");
         break;
     }
 }

 void mcf_uart_write(void *opaque, hwaddr addr,
                     uint64_t val, unsigned size)
 {
     mcf_uart_state *s = (mcf_uart_state *)opaque;
     switch (addr & 0x3f) {
     case 0x00:
         s->mr[s->current_mr] = val;
         s->current_mr = 1;
         break;
     case 0x04:
         /* CSR is ignored.  */
         break;
     case 0x08: /* Command Register.  */
         mcf_do_command(s, val);
         break;
     case 0x0c: /* Transmit Buffer.  */
         s->sr &= ~MCF_UART_TxEMP;
         s->tb = val;
         mcf_uart_do_tx(s);
         break;
     case 0x10:
         /* ACR is ignored.  */
         break;
     case 0x14:
         s->imr = val;
         break;
     default:
         break;
     }
     mcf_uart_update(s);
 }

 static void mcf_uart_reset(DeviceState *dev)
 {
     mcf_uart_state *s = MCF_UART(dev);

     s->fifo_len = 0;
     s->mr[0] = 0;
     s->mr[1] = 0;
     s->sr = MCF_UART_TxEMP;
     s->tx_enabled = 0;
     s->rx_enabled = 0;
     s->isr = 0;
     s->imr = 0;
 }

 static void mcf_uart_push_byte(mcf_uart_state *s, uint8_t data)
 {
     /* Break events overwrite the last byte if the fifo is full.  */
     if (s->fifo_len == FIFO_DEPTH) {
         s->fifo_len--;
     }

     s->fifo[s->fifo_len] = data;
     s->fifo_len++;
     s->sr |= MCF_UART_RxRDY;
     if (s->fifo_len == FIFO_DEPTH) {
         s->sr |= MCF_UART_FFULL;
     }

     mcf_uart_update(s);
 }

 static void mcf_uart_event(void *opaque, QEMUChrEvent event)
 {
     mcf_uart_state *s = (mcf_uart_state *)opaque;

     switch (event) {
     case CHR_EVENT_BREAK:
         s->isr |= MCF_UART_DBINT;
         mcf_uart_push_byte(s, 0);
         break;
     default:
         break;
     }
 }

 static int mcf_uart_can_receive(void *opaque)
 {
     mcf_uart_state *s = (mcf_uart_state *)opaque;

     return s->rx_enabled ? FIFO_DEPTH - s->fifo_len : 0;
 }

 static void mcf_uart_receive(void *opaque, const uint8_t *buf, int size)
 {
     mcf_uart_state *s = (mcf_uart_state *)opaque;

     for (int i = 0; i < size; i++) {
         mcf_uart_push_byte(s, buf[i]);
     }
 }

 static const MemoryRegionOps mcf_uart_ops = {
     .read = mcf_uart_read,
     .write = mcf_uart_write,
     .endianness = DEVICE_NATIVE_ENDIAN,
 };

 static void mcf_uart_instance_init(Object *obj)
 {
     SysBusDevice *dev = SYS_BUS_DEVICE(obj);
     mcf_uart_state *s = MCF_UART(dev);

     memory_region_init_io(&s->iomem, obj, &mcf_uart_ops, s, "uart", 0x40);
     sysbus_init_mmio(dev, &s->iomem);

     sysbus_init_irq(dev, &s->irq);
 }

 static void mcf_uart_realize(DeviceState *dev, Error **errp)
 {
     mcf_uart_state *s = MCF_UART(dev);

     qemu_chr_fe_set_handlers(&s->chr, mcf_uart_can_receive, mcf_uart_receive,
                              mcf_uart_event, NULL, s, NULL, true);
 }

 static const Property mcf_uart_properties[] = {
     DEFINE_PROP_CHR("chardev", mcf_uart_state, chr),
 };

 static void mcf_uart_class_init(ObjectClass *oc, const void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(oc);

     dc->realize = mcf_uart_realize;
     device_class_set_legacy_reset(dc, mcf_uart_reset);
     device_class_set_props(dc, mcf_uart_properties);
     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
 }

 static const TypeInfo mcf_uart_info = {
     .name          = TYPE_MCF_UART,
     .parent        = TYPE_SYS_BUS_DEVICE,
     .instance_size = sizeof(mcf_uart_state),
     .instance_init = mcf_uart_instance_init,
     .class_init    = mcf_uart_class_init,
 };

 static void mcf_uart_register(void)
 {
     type_register_static(&mcf_uart_info);
 }

 type_init(mcf_uart_register)

 DeviceState *mcf_uart_create(qemu_irq irq, Chardev *chrdrv)
 {
     DeviceState *dev;

     dev = qdev_new(TYPE_MCF_UART);
     if (chrdrv) {
         qdev_prop_set_chr(dev, "chardev", chrdrv);
     }
     sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal);
     sysbus_connect_irq(SYS_BUS_DEVICE(dev), 0, irq);

     return dev;
 }

 DeviceState *mcf_uart_create_mmap(hwaddr base, qemu_irq irq, Chardev *chrdrv)
 {
     DeviceState *dev;

     dev = mcf_uart_create(irq, chrdrv);
     sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0, base);

     return dev;
 }
	/*
	* ColdFire UART emulation.
	*
	* Copyright (c) 2007 CodeSourcery.
	*
	* This code is licensed under the GPL
	*/

	#include "qemu/osdep.h"
	#include "hw/irq.h"
	#include "hw/sysbus.h"
	#include "qemu/module.h"
	#include "qapi/error.h"
	#include "hw/m68k/mcf.h"
	#include "hw/qdev-properties.h"
	#include "hw/qdev-properties-system.h"
	#include "chardev/char-fe.h"
	#include "qom/object.h"

	#define FIFO_DEPTH 4

	struct mcf_uart_state {
	SysBusDevice parent_obj;

	MemoryRegion iomem;
	uint8_t mr[2];
	uint8_t sr;
	uint8_t isr;
	uint8_t imr;
	uint8_t bg1;
	uint8_t bg2;
	uint8_t fifo[FIFO_DEPTH];
	uint8_t tb;
	int current_mr;
	int fifo_len;
	int tx_enabled;
	int rx_enabled;
	qemu_irq irq;
	CharBackend chr;
	};

	#define TYPE_MCF_UART "mcf-uart"
	OBJECT_DECLARE_SIMPLE_TYPE(mcf_uart_state, MCF_UART)

	/* UART Status Register bits. */
	#define MCF_UART_RxRDY 0x01
	#define MCF_UART_FFULL 0x02
	#define MCF_UART_TxRDY 0x04
	#define MCF_UART_TxEMP 0x08
	#define MCF_UART_OE 0x10
	#define MCF_UART_PE 0x20
	#define MCF_UART_FE 0x40
	#define MCF_UART_RB 0x80

	/* Interrupt flags. */
	#define MCF_UART_TxINT 0x01
	#define MCF_UART_RxINT 0x02
	#define MCF_UART_DBINT 0x04
	#define MCF_UART_COSINT 0x80

	/* UMR1 flags. */
	#define MCF_UART_BC0 0x01
	#define MCF_UART_BC1 0x02
	#define MCF_UART_PT 0x04
	#define MCF_UART_PM0 0x08
	#define MCF_UART_PM1 0x10
	#define MCF_UART_ERR 0x20
	#define MCF_UART_RxIRQ 0x40
	#define MCF_UART_RxRTS 0x80

	static void mcf_uart_update(mcf_uart_state *s)
	{
	s->isr &= ~(MCF_UART_TxINT \| MCF_UART_RxINT);
	if (s->sr & MCF_UART_TxRDY)
	s->isr \|= MCF_UART_TxINT;
	if ((s->sr & ((s->mr[0] & MCF_UART_RxIRQ)
	? MCF_UART_FFULL : MCF_UART_RxRDY)) != 0)
	s->isr \|= MCF_UART_RxINT;

	qemu_set_irq(s->irq, (s->isr & s->imr) != 0);
	}

	uint64_t mcf_uart_read(void *opaque, hwaddr addr,
	unsigned size)
	{
	mcf_uart_state s = (mcf_uart_state )opaque;
	switch (addr & 0x3f) {
	case 0x00:
	return s->mr[s->current_mr];
	case 0x04:
	return s->sr;
	case 0x0c:
	{
	uint8_t val;
	int i;

	if (s->fifo_len == 0)
	return 0;

	val = s->fifo[0];
	s->fifo_len--;
	for (i = 0; i < s->fifo_len; i++)
	s->fifo[i] = s->fifo[i + 1];
	s->sr &= ~MCF_UART_FFULL;
	if (s->fifo_len == 0)
	s->sr &= ~MCF_UART_RxRDY;
	mcf_uart_update(s);
	qemu_chr_fe_accept_input(&s->chr);
	return val;
	}
	case 0x10:
	/* TODO: Implement IPCR. */
	return 0;
	case 0x14:
	return s->isr;
	case 0x18:
	return s->bg1;
	case 0x1c:
	return s->bg2;
	default:
	return 0;
	}
	}

	/* Update TxRDY flag and set data if present and enabled. */
	static void mcf_uart_do_tx(mcf_uart_state *s)
	{
	if (s->tx_enabled && (s->sr & MCF_UART_TxEMP) == 0) {
	/* XXX this blocks entire thread. Rewrite to use
	* qemu_chr_fe_write and background I/O callbacks */
	qemu_chr_fe_write_all(&s->chr, (unsigned char *)&s->tb, 1);
	s->sr \|= MCF_UART_TxEMP;
	}
	if (s->tx_enabled) {
	s->sr \|= MCF_UART_TxRDY;
	} else {
	s->sr &= ~MCF_UART_TxRDY;
	}
	}

	static void mcf_do_command(mcf_uart_state *s, uint8_t cmd)
	{
	/* Misc command. */
	switch ((cmd >> 4) & 7) {
	case 0: /* No-op. */
	break;
	case 1: /* Reset mode register pointer. */
	s->current_mr = 0;
	break;
	case 2: /* Reset receiver. */
	s->rx_enabled = 0;
	s->fifo_len = 0;
	s->sr &= ~(MCF_UART_RxRDY \| MCF_UART_FFULL);
	break;
	case 3: /* Reset transmitter. */
	s->tx_enabled = 0;
	s->sr \|= MCF_UART_TxEMP;
	s->sr &= ~MCF_UART_TxRDY;
	break;
	case 4: /* Reset error status. */
	break;
	case 5: /* Reset break-change interrupt. */
	s->isr &= ~MCF_UART_DBINT;
	break;
	case 6: /* Start break. */
	case 7: /* Stop break. */
	break;
	}

	/* Transmitter command. */
	switch ((cmd >> 2) & 3) {
	case 0: /* No-op. */
	break;
	case 1: /* Enable. */
	s->tx_enabled = 1;
	mcf_uart_do_tx(s);
	break;
	case 2: /* Disable. */
	s->tx_enabled = 0;
	mcf_uart_do_tx(s);
	break;
	case 3: /* Reserved. */
	fprintf(stderr, "mcf_uart: Bad TX command\n");
	break;
	}

	/* Receiver command. */
	switch (cmd & 3) {
	case 0: /* No-op. */
	break;
	case 1: /* Enable. */
	s->rx_enabled = 1;
	break;
	case 2:
	s->rx_enabled = 0;
	break;
	case 3: /* Reserved. */
	fprintf(stderr, "mcf_uart: Bad RX command\n");
	break;
	}
	}

	void mcf_uart_write(void *opaque, hwaddr addr,
	uint64_t val, unsigned size)
	{
	mcf_uart_state s = (mcf_uart_state )opaque;
	switch (addr & 0x3f) {
	case 0x00:
	s->mr[s->current_mr] = val;
	s->current_mr = 1;
	break;
	case 0x04:
	/* CSR is ignored. */
	break;
	case 0x08: /* Command Register. */
	mcf_do_command(s, val);
	break;
	case 0x0c: /* Transmit Buffer. */
	s->sr &= ~MCF_UART_TxEMP;
	s->tb = val;
	mcf_uart_do_tx(s);
	break;
	case 0x10:
	/* ACR is ignored. */
	break;
	case 0x14:
	s->imr = val;
	break;
	default:
	break;
	}
	mcf_uart_update(s);
	}

	static void mcf_uart_reset(DeviceState *dev)
	{
	mcf_uart_state *s = MCF_UART(dev);

	s->fifo_len = 0;
	s->mr[0] = 0;
	s->mr[1] = 0;
	s->sr = MCF_UART_TxEMP;
	s->tx_enabled = 0;
	s->rx_enabled = 0;
	s->isr = 0;
	s->imr = 0;
	}

	static void mcf_uart_push_byte(mcf_uart_state *s, uint8_t data)
	{
	/* Break events overwrite the last byte if the fifo is full. */
	if (s->fifo_len == FIFO_DEPTH) {
	s->fifo_len--;
	}

	s->fifo[s->fifo_len] = data;
	s->fifo_len++;
	s->sr \|= MCF_UART_RxRDY;
	if (s->fifo_len == FIFO_DEPTH) {
	s->sr \|= MCF_UART_FFULL;
	}

	mcf_uart_update(s);
	}

	static void mcf_uart_event(void *opaque, QEMUChrEvent event)
	{
	mcf_uart_state s = (mcf_uart_state )opaque;

	switch (event) {
	case CHR_EVENT_BREAK:
	s->isr \|= MCF_UART_DBINT;
	mcf_uart_push_byte(s, 0);
	break;
	default:
	break;
	}
	}

	static int mcf_uart_can_receive(void *opaque)
	{
	mcf_uart_state s = (mcf_uart_state )opaque;

	return s->rx_enabled ? FIFO_DEPTH - s->fifo_len : 0;
	}

	static void mcf_uart_receive(void opaque, const uint8_t buf, int size)
	{
	mcf_uart_state s = (mcf_uart_state )opaque;

	for (int i = 0; i < size; i++) {
	mcf_uart_push_byte(s, buf[i]);
	}
	}

	static const MemoryRegionOps mcf_uart_ops = {
	.read = mcf_uart_read,
	.write = mcf_uart_write,
	.endianness = DEVICE_NATIVE_ENDIAN,
	};

	static void mcf_uart_instance_init(Object *obj)
	{
	SysBusDevice *dev = SYS_BUS_DEVICE(obj);
	mcf_uart_state *s = MCF_UART(dev);

	memory_region_init_io(&s->iomem, obj, &mcf_uart_ops, s, "uart", 0x40);
	sysbus_init_mmio(dev, &s->iomem);

	sysbus_init_irq(dev, &s->irq);
	}

	static void mcf_uart_realize(DeviceState dev, Error *errp)
	{
	mcf_uart_state *s = MCF_UART(dev);

	qemu_chr_fe_set_handlers(&s->chr, mcf_uart_can_receive, mcf_uart_receive,
	mcf_uart_event, NULL, s, NULL, true);
	}

	static const Property mcf_uart_properties[] = {
	DEFINE_PROP_CHR("chardev", mcf_uart_state, chr),
	};

	static void mcf_uart_class_init(ObjectClass oc, const void data)
	{
	DeviceClass *dc = DEVICE_CLASS(oc);

	dc->realize = mcf_uart_realize;
	device_class_set_legacy_reset(dc, mcf_uart_reset);
	device_class_set_props(dc, mcf_uart_properties);
	set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
	}

	static const TypeInfo mcf_uart_info = {
	.name = TYPE_MCF_UART,
	.parent = TYPE_SYS_BUS_DEVICE,
	.instance_size = sizeof(mcf_uart_state),
	.instance_init = mcf_uart_instance_init,
	.class_init = mcf_uart_class_init,
	};

	static void mcf_uart_register(void)
	{
	type_register_static(&mcf_uart_info);
	}

	type_init(mcf_uart_register)

	DeviceState mcf_uart_create(qemu_irq irq, Chardev chrdrv)
	{
	DeviceState *dev;

	dev = qdev_new(TYPE_MCF_UART);
	if (chrdrv) {
	qdev_prop_set_chr(dev, "chardev", chrdrv);
	}
	sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal);
	sysbus_connect_irq(SYS_BUS_DEVICE(dev), 0, irq);

	return dev;
	}

	DeviceState mcf_uart_create_mmap(hwaddr base, qemu_irq irq, Chardev chrdrv)
	{
	DeviceState *dev;

	dev = mcf_uart_create(irq, chrdrv);
	sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0, base);

	return dev;
	}