hw/adc/zynq-xadc.c - qemu - Git at Google

 /*
  * ADC registers for Xilinx Zynq Platform
  *
  * Copyright (c) 2015 Guenter Roeck
  * Based on hw/misc/zynq_slcr.c, written by Michal Simek
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
  * as published by the Free Software Foundation; either version
  * 2 of the License, or (at your option) any later version.
  *
  * You should have received a copy of the GNU General Public License along
  * with this program; if not, see <http://www.gnu.org/licenses/>.
  */

 #include "qemu/osdep.h"
 #include "hw/irq.h"
 #include "hw/adc/zynq-xadc.h"
 #include "migration/vmstate.h"
 #include "qemu/timer.h"
 #include "qemu/log.h"
 #include "qemu/module.h"

 enum {
     CFG                = 0x000 / 4,
     INT_STS,
     INT_MASK,
     MSTS,
     CMDFIFO,
     RDFIFO,
     MCTL,
 };

 #define CFG_ENABLE              BIT(31)
 #define CFG_CFIFOTH_SHIFT       20
 #define CFG_CFIFOTH_LENGTH      4
 #define CFG_DFIFOTH_SHIFT       16
 #define CFG_DFIFOTH_LENGTH      4
 #define CFG_WEDGE               BIT(13)
 #define CFG_REDGE               BIT(12)
 #define CFG_TCKRATE_SHIFT       8
 #define CFG_TCKRATE_LENGTH      2

 #define CFG_TCKRATE_DIV(x)      (0x1 << (x - 1))

 #define CFG_IGAP_SHIFT          0
 #define CFG_IGAP_LENGTH         5

 #define INT_CFIFO_LTH           BIT(9)
 #define INT_DFIFO_GTH           BIT(8)
 #define INT_OT                  BIT(7)
 #define INT_ALM_SHIFT           0
 #define INT_ALM_LENGTH          7
 #define INT_ALM_MASK            (((1 << INT_ALM_LENGTH) - 1) << INT_ALM_SHIFT)

 #define INT_ALL (INT_CFIFO_LTH | INT_DFIFO_GTH | INT_OT | INT_ALM_MASK)

 #define MSTS_CFIFO_LVL_SHIFT    16
 #define MSTS_CFIFO_LVL_LENGTH   4
 #define MSTS_DFIFO_LVL_SHIFT    12
 #define MSTS_DFIFO_LVL_LENGTH   4
 #define MSTS_CFIFOF             BIT(11)
 #define MSTS_CFIFOE             BIT(10)
 #define MSTS_DFIFOF             BIT(9)
 #define MSTS_DFIFOE             BIT(8)
 #define MSTS_OT                 BIT(7)
 #define MSTS_ALM_SHIFT          0
 #define MSTS_ALM_LENGTH         7

 #define MCTL_RESET              BIT(4)

 #define CMD_NOP                 0x00
 #define CMD_READ                0x01
 #define CMD_WRITE               0x02

 static void zynq_xadc_update_ints(ZynqXADCState *s)
 {

     /* We are fast, commands are actioned instantly so the CFIFO is always
      * empty (and below threshold).
      */
     s->regs[INT_STS] |= INT_CFIFO_LTH;

     if (s->xadc_dfifo_entries >
         extract32(s->regs[CFG], CFG_DFIFOTH_SHIFT, CFG_DFIFOTH_LENGTH)) {
         s->regs[INT_STS] |= INT_DFIFO_GTH;
     }

     qemu_set_irq(s->irq, !!(s->regs[INT_STS] & ~s->regs[INT_MASK]));
 }

 static void zynq_xadc_reset(DeviceState *d)
 {
     ZynqXADCState *s = ZYNQ_XADC(d);

     s->regs[CFG] = 0x14 << CFG_IGAP_SHIFT |
                    CFG_TCKRATE_DIV(4) << CFG_TCKRATE_SHIFT | CFG_REDGE;
     s->regs[INT_STS] = INT_CFIFO_LTH;
     s->regs[INT_MASK] = 0xffffffff;
     s->regs[CMDFIFO] = 0;
     s->regs[RDFIFO] = 0;
     s->regs[MCTL] = MCTL_RESET;

     memset(s->xadc_regs, 0, sizeof(s->xadc_regs));
     memset(s->xadc_dfifo, 0, sizeof(s->xadc_dfifo));
     s->xadc_dfifo_entries = 0;

     zynq_xadc_update_ints(s);
 }

 static uint16_t xadc_pop_dfifo(ZynqXADCState *s)
 {
     uint16_t rv = s->xadc_dfifo[0];
     int i;

     if (s->xadc_dfifo_entries > 0) {
         s->xadc_dfifo_entries--;
     }
     for (i = 0; i < s->xadc_dfifo_entries; i++) {
         s->xadc_dfifo[i] = s->xadc_dfifo[i + 1];
     }
     s->xadc_dfifo[s->xadc_dfifo_entries] = 0;
     zynq_xadc_update_ints(s);
     return rv;
 }

 static void xadc_push_dfifo(ZynqXADCState *s, uint16_t regval)
 {
     if (s->xadc_dfifo_entries < ZYNQ_XADC_FIFO_DEPTH) {
         s->xadc_dfifo[s->xadc_dfifo_entries++] = s->xadc_read_reg_previous;
     }
     s->xadc_read_reg_previous = regval;
     zynq_xadc_update_ints(s);
 }

 static bool zynq_xadc_check_offset(hwaddr offset, bool rnw)
 {
     switch (offset) {
     case CFG:
     case INT_MASK:
     case INT_STS:
     case MCTL:
         return true;
     case RDFIFO:
     case MSTS:
         return rnw;     /* read only */
     case CMDFIFO:
         return !rnw;    /* write only */
     default:
         return false;
     }
 }

 static uint64_t zynq_xadc_read(void *opaque, hwaddr offset, unsigned size)
 {
     ZynqXADCState *s = opaque;
     int reg = offset / 4;
     uint32_t rv = 0;

     if (!zynq_xadc_check_offset(reg, true)) {
         qemu_log_mask(LOG_GUEST_ERROR, "zynq_xadc: Invalid read access to "
                       "addr %" HWADDR_PRIx "\n", offset);
         return 0;
     }

     switch (reg) {
     case CFG:
     case INT_MASK:
     case INT_STS:
     case MCTL:
         rv = s->regs[reg];
         break;
     case MSTS:
         rv = MSTS_CFIFOE;
         rv |= s->xadc_dfifo_entries << MSTS_DFIFO_LVL_SHIFT;
         if (!s->xadc_dfifo_entries) {
             rv |= MSTS_DFIFOE;
         } else if (s->xadc_dfifo_entries == ZYNQ_XADC_FIFO_DEPTH) {
             rv |= MSTS_DFIFOF;
         }
         break;
     case RDFIFO:
         rv = xadc_pop_dfifo(s);
         break;
     }
     return rv;
 }

 static void zynq_xadc_write(void *opaque, hwaddr offset, uint64_t val,
                             unsigned size)
 {
     ZynqXADCState *s = (ZynqXADCState *)opaque;
     int reg = offset / 4;
     int xadc_reg;
     int xadc_cmd;
     int xadc_data;

     if (!zynq_xadc_check_offset(reg, false)) {
         qemu_log_mask(LOG_GUEST_ERROR, "zynq_xadc: Invalid write access "
                       "to addr %" HWADDR_PRIx "\n", offset);
         return;
     }

     switch (reg) {
     case CFG:
         s->regs[CFG] = val;
         break;
     case INT_STS:
         s->regs[INT_STS] &= ~val;
         break;
     case INT_MASK:
         s->regs[INT_MASK] = val & INT_ALL;
         break;
     case CMDFIFO:
         xadc_cmd  = extract32(val, 26,  4);
         xadc_reg  = extract32(val, 16, 10);
         xadc_data = extract32(val,  0, 16);

         if (s->regs[MCTL] & MCTL_RESET) {
             qemu_log_mask(LOG_GUEST_ERROR, "zynq_xadc: Sending command "
                           "while comm channel held in reset: %" PRIx32 "\n",
                           (uint32_t) val);
             break;
         }

         if (xadc_reg >= ZYNQ_XADC_NUM_ADC_REGS && xadc_cmd != CMD_NOP) {
             qemu_log_mask(LOG_GUEST_ERROR, "read/write op to invalid xadc "
                           "reg 0x%x\n", xadc_reg);
             break;
         }

         switch (xadc_cmd) {
         case CMD_READ:
             xadc_push_dfifo(s, s->xadc_regs[xadc_reg]);
             break;
         case CMD_WRITE:
             s->xadc_regs[xadc_reg] = xadc_data;
             /* fallthrough */
         case CMD_NOP:
             xadc_push_dfifo(s, 0);
             break;
         }
         break;
     case MCTL:
         s->regs[MCTL] = val & 0x00fffeff;
         break;
     }
     zynq_xadc_update_ints(s);
 }

 static const MemoryRegionOps xadc_ops = {
     .read = zynq_xadc_read,
     .write = zynq_xadc_write,
     .endianness = DEVICE_NATIVE_ENDIAN,
 };

 static void zynq_xadc_init(Object *obj)
 {
     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
     ZynqXADCState *s = ZYNQ_XADC(obj);

     memory_region_init_io(&s->iomem, obj, &xadc_ops, s, "zynq-xadc",
                           ZYNQ_XADC_MMIO_SIZE);
     sysbus_init_mmio(sbd, &s->iomem);
     sysbus_init_irq(sbd, &s->irq);
 }

 static const VMStateDescription vmstate_zynq_xadc = {
     .name = "zynq-xadc",
     .version_id = 1,
     .minimum_version_id = 1,
     .fields = (const VMStateField[]) {
         VMSTATE_UINT32_ARRAY(regs, ZynqXADCState, ZYNQ_XADC_NUM_IO_REGS),
         VMSTATE_UINT16_ARRAY(xadc_regs, ZynqXADCState,
                              ZYNQ_XADC_NUM_ADC_REGS),
         VMSTATE_UINT16_ARRAY(xadc_dfifo, ZynqXADCState,
                              ZYNQ_XADC_FIFO_DEPTH),
         VMSTATE_UINT16(xadc_read_reg_previous, ZynqXADCState),
         VMSTATE_UINT16(xadc_dfifo_entries, ZynqXADCState),
         VMSTATE_END_OF_LIST()
     }
 };

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

     dc->vmsd = &vmstate_zynq_xadc;
     dc->reset = zynq_xadc_reset;
 }

 static const TypeInfo zynq_xadc_info = {
     .class_init = zynq_xadc_class_init,
     .name  = TYPE_ZYNQ_XADC,
     .parent = TYPE_SYS_BUS_DEVICE,
     .instance_size  = sizeof(ZynqXADCState),
     .instance_init = zynq_xadc_init,
 };

 static void zynq_xadc_register_types(void)
 {
     type_register_static(&zynq_xadc_info);
 }

 type_init(zynq_xadc_register_types)
	/*
	* ADC registers for Xilinx Zynq Platform
	*
	* Copyright (c) 2015 Guenter Roeck
	* Based on hw/misc/zynq_slcr.c, written by Michal Simek
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License
	* as published by the Free Software Foundation; either version
	* 2 of the License, or (at your option) any later version.
	*
	* You should have received a copy of the GNU General Public License along
	* with this program; if not, see <http://www.gnu.org/licenses/>.
	*/

	#include "qemu/osdep.h"
	#include "hw/irq.h"
	#include "hw/adc/zynq-xadc.h"
	#include "migration/vmstate.h"
	#include "qemu/timer.h"
	#include "qemu/log.h"
	#include "qemu/module.h"

	enum {
	CFG = 0x000 / 4,
	INT_STS,
	INT_MASK,
	MSTS,
	CMDFIFO,
	RDFIFO,
	MCTL,
	};

	#define CFG_ENABLE BIT(31)
	#define CFG_CFIFOTH_SHIFT 20
	#define CFG_CFIFOTH_LENGTH 4
	#define CFG_DFIFOTH_SHIFT 16
	#define CFG_DFIFOTH_LENGTH 4
	#define CFG_WEDGE BIT(13)
	#define CFG_REDGE BIT(12)
	#define CFG_TCKRATE_SHIFT 8
	#define CFG_TCKRATE_LENGTH 2

	#define CFG_TCKRATE_DIV(x) (0x1 << (x - 1))

	#define CFG_IGAP_SHIFT 0
	#define CFG_IGAP_LENGTH 5

	#define INT_CFIFO_LTH BIT(9)
	#define INT_DFIFO_GTH BIT(8)
	#define INT_OT BIT(7)
	#define INT_ALM_SHIFT 0
	#define INT_ALM_LENGTH 7
	#define INT_ALM_MASK (((1 << INT_ALM_LENGTH) - 1) << INT_ALM_SHIFT)

	#define INT_ALL (INT_CFIFO_LTH \| INT_DFIFO_GTH \| INT_OT \| INT_ALM_MASK)

	#define MSTS_CFIFO_LVL_SHIFT 16
	#define MSTS_CFIFO_LVL_LENGTH 4
	#define MSTS_DFIFO_LVL_SHIFT 12
	#define MSTS_DFIFO_LVL_LENGTH 4
	#define MSTS_CFIFOF BIT(11)
	#define MSTS_CFIFOE BIT(10)
	#define MSTS_DFIFOF BIT(9)
	#define MSTS_DFIFOE BIT(8)
	#define MSTS_OT BIT(7)
	#define MSTS_ALM_SHIFT 0
	#define MSTS_ALM_LENGTH 7

	#define MCTL_RESET BIT(4)

	#define CMD_NOP 0x00
	#define CMD_READ 0x01
	#define CMD_WRITE 0x02

	static void zynq_xadc_update_ints(ZynqXADCState *s)
	{

	/* We are fast, commands are actioned instantly so the CFIFO is always
	* empty (and below threshold).
	*/
	s->regs[INT_STS] \|= INT_CFIFO_LTH;

	if (s->xadc_dfifo_entries >
	extract32(s->regs[CFG], CFG_DFIFOTH_SHIFT, CFG_DFIFOTH_LENGTH)) {
	s->regs[INT_STS] \|= INT_DFIFO_GTH;
	}

	qemu_set_irq(s->irq, !!(s->regs[INT_STS] & ~s->regs[INT_MASK]));
	}

	static void zynq_xadc_reset(DeviceState *d)
	{
	ZynqXADCState *s = ZYNQ_XADC(d);

	s->regs[CFG] = 0x14 << CFG_IGAP_SHIFT \|
	CFG_TCKRATE_DIV(4) << CFG_TCKRATE_SHIFT \| CFG_REDGE;
	s->regs[INT_STS] = INT_CFIFO_LTH;
	s->regs[INT_MASK] = 0xffffffff;
	s->regs[CMDFIFO] = 0;
	s->regs[RDFIFO] = 0;
	s->regs[MCTL] = MCTL_RESET;

	memset(s->xadc_regs, 0, sizeof(s->xadc_regs));
	memset(s->xadc_dfifo, 0, sizeof(s->xadc_dfifo));
	s->xadc_dfifo_entries = 0;

	zynq_xadc_update_ints(s);
	}

	static uint16_t xadc_pop_dfifo(ZynqXADCState *s)
	{
	uint16_t rv = s->xadc_dfifo[0];
	int i;

	if (s->xadc_dfifo_entries > 0) {
	s->xadc_dfifo_entries--;
	}
	for (i = 0; i < s->xadc_dfifo_entries; i++) {
	s->xadc_dfifo[i] = s->xadc_dfifo[i + 1];
	}
	s->xadc_dfifo[s->xadc_dfifo_entries] = 0;
	zynq_xadc_update_ints(s);
	return rv;
	}

	static void xadc_push_dfifo(ZynqXADCState *s, uint16_t regval)
	{
	if (s->xadc_dfifo_entries < ZYNQ_XADC_FIFO_DEPTH) {
	s->xadc_dfifo[s->xadc_dfifo_entries++] = s->xadc_read_reg_previous;
	}
	s->xadc_read_reg_previous = regval;
	zynq_xadc_update_ints(s);
	}

	static bool zynq_xadc_check_offset(hwaddr offset, bool rnw)
	{
	switch (offset) {
	case CFG:
	case INT_MASK:
	case INT_STS:
	case MCTL:
	return true;
	case RDFIFO:
	case MSTS:
	return rnw; /* read only */
	case CMDFIFO:
	return !rnw; /* write only */
	default:
	return false;
	}
	}

	static uint64_t zynq_xadc_read(void *opaque, hwaddr offset, unsigned size)
	{
	ZynqXADCState *s = opaque;
	int reg = offset / 4;
	uint32_t rv = 0;

	if (!zynq_xadc_check_offset(reg, true)) {
	qemu_log_mask(LOG_GUEST_ERROR, "zynq_xadc: Invalid read access to "
	"addr %" HWADDR_PRIx "\n", offset);
	return 0;
	}

	switch (reg) {
	case CFG:
	case INT_MASK:
	case INT_STS:
	case MCTL:
	rv = s->regs[reg];
	break;
	case MSTS:
	rv = MSTS_CFIFOE;
	rv \|= s->xadc_dfifo_entries << MSTS_DFIFO_LVL_SHIFT;
	if (!s->xadc_dfifo_entries) {
	rv \|= MSTS_DFIFOE;
	} else if (s->xadc_dfifo_entries == ZYNQ_XADC_FIFO_DEPTH) {
	rv \|= MSTS_DFIFOF;
	}
	break;
	case RDFIFO:
	rv = xadc_pop_dfifo(s);
	break;
	}
	return rv;
	}

	static void zynq_xadc_write(void *opaque, hwaddr offset, uint64_t val,
	unsigned size)
	{
	ZynqXADCState s = (ZynqXADCState )opaque;
	int reg = offset / 4;
	int xadc_reg;
	int xadc_cmd;
	int xadc_data;

	if (!zynq_xadc_check_offset(reg, false)) {
	qemu_log_mask(LOG_GUEST_ERROR, "zynq_xadc: Invalid write access "
	"to addr %" HWADDR_PRIx "\n", offset);
	return;
	}

	switch (reg) {
	case CFG:
	s->regs[CFG] = val;
	break;
	case INT_STS:
	s->regs[INT_STS] &= ~val;
	break;
	case INT_MASK:
	s->regs[INT_MASK] = val & INT_ALL;
	break;
	case CMDFIFO:
	xadc_cmd = extract32(val, 26, 4);
	xadc_reg = extract32(val, 16, 10);
	xadc_data = extract32(val, 0, 16);

	if (s->regs[MCTL] & MCTL_RESET) {
	qemu_log_mask(LOG_GUEST_ERROR, "zynq_xadc: Sending command "
	"while comm channel held in reset: %" PRIx32 "\n",
	(uint32_t) val);
	break;
	}

	if (xadc_reg >= ZYNQ_XADC_NUM_ADC_REGS && xadc_cmd != CMD_NOP) {
	qemu_log_mask(LOG_GUEST_ERROR, "read/write op to invalid xadc "
	"reg 0x%x\n", xadc_reg);
	break;
	}

	switch (xadc_cmd) {
	case CMD_READ:
	xadc_push_dfifo(s, s->xadc_regs[xadc_reg]);
	break;
	case CMD_WRITE:
	s->xadc_regs[xadc_reg] = xadc_data;
	/* fallthrough */
	case CMD_NOP:
	xadc_push_dfifo(s, 0);
	break;
	}
	break;
	case MCTL:
	s->regs[MCTL] = val & 0x00fffeff;
	break;
	}
	zynq_xadc_update_ints(s);
	}

	static const MemoryRegionOps xadc_ops = {
	.read = zynq_xadc_read,
	.write = zynq_xadc_write,
	.endianness = DEVICE_NATIVE_ENDIAN,
	};

	static void zynq_xadc_init(Object *obj)
	{
	SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
	ZynqXADCState *s = ZYNQ_XADC(obj);

	memory_region_init_io(&s->iomem, obj, &xadc_ops, s, "zynq-xadc",
	ZYNQ_XADC_MMIO_SIZE);
	sysbus_init_mmio(sbd, &s->iomem);
	sysbus_init_irq(sbd, &s->irq);
	}

	static const VMStateDescription vmstate_zynq_xadc = {
	.name = "zynq-xadc",
	.version_id = 1,
	.minimum_version_id = 1,
	.fields = (const VMStateField[]) {
	VMSTATE_UINT32_ARRAY(regs, ZynqXADCState, ZYNQ_XADC_NUM_IO_REGS),
	VMSTATE_UINT16_ARRAY(xadc_regs, ZynqXADCState,
	ZYNQ_XADC_NUM_ADC_REGS),
	VMSTATE_UINT16_ARRAY(xadc_dfifo, ZynqXADCState,
	ZYNQ_XADC_FIFO_DEPTH),
	VMSTATE_UINT16(xadc_read_reg_previous, ZynqXADCState),
	VMSTATE_UINT16(xadc_dfifo_entries, ZynqXADCState),
	VMSTATE_END_OF_LIST()
	}
	};

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

	dc->vmsd = &vmstate_zynq_xadc;
	dc->reset = zynq_xadc_reset;
	}

	static const TypeInfo zynq_xadc_info = {
	.class_init = zynq_xadc_class_init,
	.name = TYPE_ZYNQ_XADC,
	.parent = TYPE_SYS_BUS_DEVICE,
	.instance_size = sizeof(ZynqXADCState),
	.instance_init = zynq_xadc_init,
	};

	static void zynq_xadc_register_types(void)
	{
	type_register_static(&zynq_xadc_info);
	}

	type_init(zynq_xadc_register_types)