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

 /*
  * QEMU ETRAX System Emulator
  *
  * Copyright (c) 2007 Edgar E. Iglesias, Axis Communications AB.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */

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

 #define D(x)

 #define RW_TR_CTRL     (0x00 / 4)
 #define RW_TR_DMA_EN   (0x04 / 4)
 #define RW_REC_CTRL    (0x08 / 4)
 #define RW_DOUT        (0x1c / 4)
 #define RS_STAT_DIN    (0x20 / 4)
 #define R_STAT_DIN     (0x24 / 4)
 #define RW_INTR_MASK   (0x2c / 4)
 #define RW_ACK_INTR    (0x30 / 4)
 #define R_INTR         (0x34 / 4)
 #define R_MASKED_INTR  (0x38 / 4)
 #define R_MAX          (0x3c / 4)

 #define STAT_DAV     16
 #define STAT_TR_IDLE 22
 #define STAT_TR_RDY  24

 #define TYPE_ETRAX_FS_SERIAL "etraxfs,serial"
 typedef struct ETRAXSerial ETRAXSerial;
 DECLARE_INSTANCE_CHECKER(ETRAXSerial, ETRAX_SERIAL,
                          TYPE_ETRAX_FS_SERIAL)

 struct ETRAXSerial {
     SysBusDevice parent_obj;

     MemoryRegion mmio;
     CharBackend chr;
     qemu_irq irq;

     int pending_tx;

     uint8_t rx_fifo[16];
     unsigned int rx_fifo_pos;
     unsigned int rx_fifo_len;

     /* Control registers.  */
     uint32_t regs[R_MAX];
 };

 static void ser_update_irq(ETRAXSerial *s)
 {

     if (s->rx_fifo_len) {
         s->regs[R_INTR] |= 8;
     } else {
         s->regs[R_INTR] &= ~8;
     }

     s->regs[R_MASKED_INTR] = s->regs[R_INTR] & s->regs[RW_INTR_MASK];
     qemu_set_irq(s->irq, !!s->regs[R_MASKED_INTR]);
 }

 static uint64_t
 ser_read(void *opaque, hwaddr addr, unsigned int size)
 {
     ETRAXSerial *s = opaque;
     uint32_t r = 0;

     addr >>= 2;
     switch (addr)
     {
         case R_STAT_DIN:
             r = s->rx_fifo[(s->rx_fifo_pos - s->rx_fifo_len) & 15];
             if (s->rx_fifo_len) {
                 r |= 1 << STAT_DAV;
             }
             r |= 1 << STAT_TR_RDY;
             r |= 1 << STAT_TR_IDLE;
             break;
         case RS_STAT_DIN:
             r = s->rx_fifo[(s->rx_fifo_pos - s->rx_fifo_len) & 15];
             if (s->rx_fifo_len) {
                 r |= 1 << STAT_DAV;
                 s->rx_fifo_len--;
             }
             r |= 1 << STAT_TR_RDY;
             r |= 1 << STAT_TR_IDLE;
             break;
         default:
             r = s->regs[addr];
             D(qemu_log("%s " TARGET_FMT_plx "=%x\n", __func__, addr, r));
             break;
     }
     return r;
 }

 static void
 ser_write(void *opaque, hwaddr addr,
           uint64_t val64, unsigned int size)
 {
     ETRAXSerial *s = opaque;
     uint32_t value = val64;
     unsigned char ch = val64;

     D(qemu_log("%s " TARGET_FMT_plx "=%x\n",  __func__, addr, value));
     addr >>= 2;
     switch (addr)
     {
         case RW_DOUT:
             /* XXX this blocks entire thread. Rewrite to use
              * qemu_chr_fe_write and background I/O callbacks */
             qemu_chr_fe_write_all(&s->chr, &ch, 1);
             s->regs[R_INTR] |= 3;
             s->pending_tx = 1;
             s->regs[addr] = value;
             break;
         case RW_ACK_INTR:
             if (s->pending_tx) {
                 value &= ~1;
                 s->pending_tx = 0;
                 D(qemu_log("fixedup value=%x r_intr=%x\n",
                            value, s->regs[R_INTR]));
             }
             s->regs[addr] = value;
             s->regs[R_INTR] &= ~value;
             D(printf("r_intr=%x\n", s->regs[R_INTR]));
             break;
         default:
             s->regs[addr] = value;
             break;
     }
     ser_update_irq(s);
 }

 static const MemoryRegionOps ser_ops = {
     .read = ser_read,
     .write = ser_write,
     .endianness = DEVICE_NATIVE_ENDIAN,
     .valid = {
         .min_access_size = 4,
         .max_access_size = 4
     }
 };

 static Property etraxfs_ser_properties[] = {
     DEFINE_PROP_CHR("chardev", ETRAXSerial, chr),
     DEFINE_PROP_END_OF_LIST(),
 };

 static void serial_receive(void *opaque, const uint8_t *buf, int size)
 {
     ETRAXSerial *s = opaque;
     int i;

     /* Got a byte.  */
     if (s->rx_fifo_len >= 16) {
         D(qemu_log("WARNING: UART dropped char.\n"));
         return;
     }

     for (i = 0; i < size; i++) {
         s->rx_fifo[s->rx_fifo_pos] = buf[i];
         s->rx_fifo_pos++;
         s->rx_fifo_pos &= 15;
         s->rx_fifo_len++;
     }

     ser_update_irq(s);
 }

 static int serial_can_receive(void *opaque)
 {
     ETRAXSerial *s = opaque;

     /* Is the receiver enabled?  */
     if (!(s->regs[RW_REC_CTRL] & (1 << 3))) {
         return 0;
     }

     return sizeof(s->rx_fifo) - s->rx_fifo_len;
 }

 static void serial_event(void *opaque, QEMUChrEvent event)
 {

 }

 static void etraxfs_ser_reset(DeviceState *d)
 {
     ETRAXSerial *s = ETRAX_SERIAL(d);

     /* transmitter begins ready and idle.  */
     s->regs[RS_STAT_DIN] |= (1 << STAT_TR_RDY);
     s->regs[RS_STAT_DIN] |= (1 << STAT_TR_IDLE);

     s->regs[RW_REC_CTRL] = 0x10000;

 }

 static void etraxfs_ser_init(Object *obj)
 {
     ETRAXSerial *s = ETRAX_SERIAL(obj);
     SysBusDevice *dev = SYS_BUS_DEVICE(obj);

     sysbus_init_irq(dev, &s->irq);
     memory_region_init_io(&s->mmio, obj, &ser_ops, s,
                           "etraxfs-serial", R_MAX * 4);
     sysbus_init_mmio(dev, &s->mmio);
 }

 static void etraxfs_ser_realize(DeviceState *dev, Error **errp)
 {
     ETRAXSerial *s = ETRAX_SERIAL(dev);

     qemu_chr_fe_set_handlers(&s->chr,
                              serial_can_receive, serial_receive,
                              serial_event, NULL, s, NULL, true);
 }

 static void etraxfs_ser_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);

     dc->reset = etraxfs_ser_reset;
     device_class_set_props(dc, etraxfs_ser_properties);
     dc->realize = etraxfs_ser_realize;
 }

 static const TypeInfo etraxfs_ser_info = {
     .name          = TYPE_ETRAX_FS_SERIAL,
     .parent        = TYPE_SYS_BUS_DEVICE,
     .instance_size = sizeof(ETRAXSerial),
     .instance_init = etraxfs_ser_init,
     .class_init    = etraxfs_ser_class_init,
 };

 static void etraxfs_serial_register_types(void)
 {
     type_register_static(&etraxfs_ser_info);
 }

 type_init(etraxfs_serial_register_types)
	/*
	* QEMU ETRAX System Emulator
	*
	* Copyright (c) 2007 Edgar E. Iglesias, Axis Communications AB.
	*
	* Permission is hereby granted, free of charge, to any person obtaining a copy
	* of this software and associated documentation files (the "Software"), to deal
	* in the Software without restriction, including without limitation the rights
	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	* copies of the Software, and to permit persons to whom the Software is
	* furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in
	* all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	* THE SOFTWARE.
	*/

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

	#define D(x)

	#define RW_TR_CTRL (0x00 / 4)
	#define RW_TR_DMA_EN (0x04 / 4)
	#define RW_REC_CTRL (0x08 / 4)
	#define RW_DOUT (0x1c / 4)
	#define RS_STAT_DIN (0x20 / 4)
	#define R_STAT_DIN (0x24 / 4)
	#define RW_INTR_MASK (0x2c / 4)
	#define RW_ACK_INTR (0x30 / 4)
	#define R_INTR (0x34 / 4)
	#define R_MASKED_INTR (0x38 / 4)
	#define R_MAX (0x3c / 4)

	#define STAT_DAV 16
	#define STAT_TR_IDLE 22
	#define STAT_TR_RDY 24

	#define TYPE_ETRAX_FS_SERIAL "etraxfs,serial"
	typedef struct ETRAXSerial ETRAXSerial;
	DECLARE_INSTANCE_CHECKER(ETRAXSerial, ETRAX_SERIAL,
	TYPE_ETRAX_FS_SERIAL)

	struct ETRAXSerial {
	SysBusDevice parent_obj;

	MemoryRegion mmio;
	CharBackend chr;
	qemu_irq irq;

	int pending_tx;

	uint8_t rx_fifo[16];
	unsigned int rx_fifo_pos;
	unsigned int rx_fifo_len;

	/* Control registers. */
	uint32_t regs[R_MAX];
	};

	static void ser_update_irq(ETRAXSerial *s)
	{

	if (s->rx_fifo_len) {
	s->regs[R_INTR] \|= 8;
	} else {
	s->regs[R_INTR] &= ~8;
	}

	s->regs[R_MASKED_INTR] = s->regs[R_INTR] & s->regs[RW_INTR_MASK];
	qemu_set_irq(s->irq, !!s->regs[R_MASKED_INTR]);
	}

	static uint64_t
	ser_read(void *opaque, hwaddr addr, unsigned int size)
	{
	ETRAXSerial *s = opaque;
	uint32_t r = 0;

	addr >>= 2;
	switch (addr)
	{
	case R_STAT_DIN:
	r = s->rx_fifo[(s->rx_fifo_pos - s->rx_fifo_len) & 15];
	if (s->rx_fifo_len) {
	r \|= 1 << STAT_DAV;
	}
	r \|= 1 << STAT_TR_RDY;
	r \|= 1 << STAT_TR_IDLE;
	break;
	case RS_STAT_DIN:
	r = s->rx_fifo[(s->rx_fifo_pos - s->rx_fifo_len) & 15];
	if (s->rx_fifo_len) {
	r \|= 1 << STAT_DAV;
	s->rx_fifo_len--;
	}
	r \|= 1 << STAT_TR_RDY;
	r \|= 1 << STAT_TR_IDLE;
	break;
	default:
	r = s->regs[addr];
	D(qemu_log("%s " TARGET_FMT_plx "=%x\n", __func__, addr, r));
	break;
	}
	return r;
	}

	static void
	ser_write(void *opaque, hwaddr addr,
	uint64_t val64, unsigned int size)
	{
	ETRAXSerial *s = opaque;
	uint32_t value = val64;
	unsigned char ch = val64;

	D(qemu_log("%s " TARGET_FMT_plx "=%x\n", __func__, addr, value));
	addr >>= 2;
	switch (addr)
	{
	case RW_DOUT:
	/* XXX this blocks entire thread. Rewrite to use
	* qemu_chr_fe_write and background I/O callbacks */
	qemu_chr_fe_write_all(&s->chr, &ch, 1);
	s->regs[R_INTR] \|= 3;
	s->pending_tx = 1;
	s->regs[addr] = value;
	break;
	case RW_ACK_INTR:
	if (s->pending_tx) {
	value &= ~1;
	s->pending_tx = 0;
	D(qemu_log("fixedup value=%x r_intr=%x\n",
	value, s->regs[R_INTR]));
	}
	s->regs[addr] = value;
	s->regs[R_INTR] &= ~value;
	D(printf("r_intr=%x\n", s->regs[R_INTR]));
	break;
	default:
	s->regs[addr] = value;
	break;
	}
	ser_update_irq(s);
	}

	static const MemoryRegionOps ser_ops = {
	.read = ser_read,
	.write = ser_write,
	.endianness = DEVICE_NATIVE_ENDIAN,
	.valid = {
	.min_access_size = 4,
	.max_access_size = 4
	}
	};

	static Property etraxfs_ser_properties[] = {
	DEFINE_PROP_CHR("chardev", ETRAXSerial, chr),
	DEFINE_PROP_END_OF_LIST(),
	};

	static void serial_receive(void opaque, const uint8_t buf, int size)
	{
	ETRAXSerial *s = opaque;
	int i;

	/* Got a byte. */
	if (s->rx_fifo_len >= 16) {
	D(qemu_log("WARNING: UART dropped char.\n"));
	return;
	}

	for (i = 0; i < size; i++) {
	s->rx_fifo[s->rx_fifo_pos] = buf[i];
	s->rx_fifo_pos++;
	s->rx_fifo_pos &= 15;
	s->rx_fifo_len++;
	}

	ser_update_irq(s);
	}

	static int serial_can_receive(void *opaque)
	{
	ETRAXSerial *s = opaque;

	/* Is the receiver enabled? */
	if (!(s->regs[RW_REC_CTRL] & (1 << 3))) {
	return 0;
	}

	return sizeof(s->rx_fifo) - s->rx_fifo_len;
	}

	static void serial_event(void *opaque, QEMUChrEvent event)
	{

	}

	static void etraxfs_ser_reset(DeviceState *d)
	{
	ETRAXSerial *s = ETRAX_SERIAL(d);

	/* transmitter begins ready and idle. */
	s->regs[RS_STAT_DIN] \|= (1 << STAT_TR_RDY);
	s->regs[RS_STAT_DIN] \|= (1 << STAT_TR_IDLE);

	s->regs[RW_REC_CTRL] = 0x10000;

	}

	static void etraxfs_ser_init(Object *obj)
	{
	ETRAXSerial *s = ETRAX_SERIAL(obj);
	SysBusDevice *dev = SYS_BUS_DEVICE(obj);

	sysbus_init_irq(dev, &s->irq);
	memory_region_init_io(&s->mmio, obj, &ser_ops, s,
	"etraxfs-serial", R_MAX * 4);
	sysbus_init_mmio(dev, &s->mmio);
	}

	static void etraxfs_ser_realize(DeviceState dev, Error *errp)
	{
	ETRAXSerial *s = ETRAX_SERIAL(dev);

	qemu_chr_fe_set_handlers(&s->chr,
	serial_can_receive, serial_receive,
	serial_event, NULL, s, NULL, true);
	}

	static void etraxfs_ser_class_init(ObjectClass klass, void data)
	{
	DeviceClass *dc = DEVICE_CLASS(klass);

	dc->reset = etraxfs_ser_reset;
	device_class_set_props(dc, etraxfs_ser_properties);
	dc->realize = etraxfs_ser_realize;
	}

	static const TypeInfo etraxfs_ser_info = {
	.name = TYPE_ETRAX_FS_SERIAL,
	.parent = TYPE_SYS_BUS_DEVICE,
	.instance_size = sizeof(ETRAXSerial),
	.instance_init = etraxfs_ser_init,
	.class_init = etraxfs_ser_class_init,
	};

	static void etraxfs_serial_register_types(void)
	{
	type_register_static(&etraxfs_ser_info);
	}

	type_init(etraxfs_serial_register_types)