hw/i2c/smbus_eeprom.c - qemu - Git at Google

 /*
  * QEMU SMBus EEPROM device
  *
  * Copyright (c) 2007 Arastra, Inc.
  *
  * 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 "qemu/units.h"
 #include "qapi/error.h"
 #include "hw/boards.h"
 #include "hw/i2c/i2c.h"
 #include "hw/i2c/smbus_slave.h"
 #include "hw/qdev-properties.h"
 #include "migration/vmstate.h"
 #include "hw/i2c/smbus_eeprom.h"
 #include "qom/object.h"

 //#define DEBUG

 #define TYPE_SMBUS_EEPROM "smbus-eeprom"

 OBJECT_DECLARE_SIMPLE_TYPE(SMBusEEPROMDevice, SMBUS_EEPROM)

 #define SMBUS_EEPROM_SIZE 256

 struct SMBusEEPROMDevice {
     SMBusDevice smbusdev;
     uint8_t data[SMBUS_EEPROM_SIZE];
     uint8_t *init_data;
     uint8_t offset;
     bool accessed;
 };

 static uint8_t eeprom_receive_byte(SMBusDevice *dev)
 {
     SMBusEEPROMDevice *eeprom = SMBUS_EEPROM(dev);
     uint8_t *data = eeprom->data;
     uint8_t val = data[eeprom->offset++];

     eeprom->accessed = true;
 #ifdef DEBUG
     printf("eeprom_receive_byte: addr=0x%02x val=0x%02x\n",
            dev->i2c.address, val);
 #endif
     return val;
 }

 static int eeprom_write_data(SMBusDevice *dev, uint8_t *buf, uint8_t len)
 {
     SMBusEEPROMDevice *eeprom = SMBUS_EEPROM(dev);
     uint8_t *data = eeprom->data;

     eeprom->accessed = true;
 #ifdef DEBUG
     printf("eeprom_write_byte: addr=0x%02x cmd=0x%02x val=0x%02x\n",
            dev->i2c.address, buf[0], buf[1]);
 #endif
     /* len is guaranteed to be > 0 */
     eeprom->offset = buf[0];
     buf++;
     len--;

     for (; len > 0; len--) {
         data[eeprom->offset] = *buf++;
         eeprom->offset = (eeprom->offset + 1) % SMBUS_EEPROM_SIZE;
     }

     return 0;
 }

 static bool smbus_eeprom_vmstate_needed(void *opaque)
 {
     MachineClass *mc = MACHINE_GET_CLASS(qdev_get_machine());
     SMBusEEPROMDevice *eeprom = opaque;

     return (eeprom->accessed || smbus_vmstate_needed(&eeprom->smbusdev)) &&
         !mc->smbus_no_migration_support;
 }

 static const VMStateDescription vmstate_smbus_eeprom = {
     .name = "smbus-eeprom",
     .version_id = 1,
     .minimum_version_id = 1,
     .needed = smbus_eeprom_vmstate_needed,
     .fields = (const VMStateField[]) {
         VMSTATE_SMBUS_DEVICE(smbusdev, SMBusEEPROMDevice),
         VMSTATE_UINT8_ARRAY(data, SMBusEEPROMDevice, SMBUS_EEPROM_SIZE),
         VMSTATE_UINT8(offset, SMBusEEPROMDevice),
         VMSTATE_BOOL(accessed, SMBusEEPROMDevice),
         VMSTATE_END_OF_LIST()
     }
 };

 /*
  * Reset the EEPROM contents to the initial state on a reset.  This
  * isn't really how an EEPROM works, of course, but the general
  * principle of QEMU is to restore function on reset to what it would
  * be if QEMU was stopped and started.
  *
  * The proper thing to do would be to have a backing blockdev to hold
  * the contents and restore that on startup, and not do this on reset.
  * But until that time, act as if we had been stopped and restarted.
  */
 static void smbus_eeprom_reset(DeviceState *dev)
 {
     SMBusEEPROMDevice *eeprom = SMBUS_EEPROM(dev);

     memcpy(eeprom->data, eeprom->init_data, SMBUS_EEPROM_SIZE);
     eeprom->offset = 0;
 }

 static void smbus_eeprom_realize(DeviceState *dev, Error **errp)
 {
     SMBusEEPROMDevice *eeprom = SMBUS_EEPROM(dev);

     smbus_eeprom_reset(dev);
     if (eeprom->init_data == NULL) {
         error_setg(errp, "init_data cannot be NULL");
     }
 }

 static void smbus_eeprom_class_initfn(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     SMBusDeviceClass *sc = SMBUS_DEVICE_CLASS(klass);

     dc->realize = smbus_eeprom_realize;
     device_class_set_legacy_reset(dc, smbus_eeprom_reset);
     sc->receive_byte = eeprom_receive_byte;
     sc->write_data = eeprom_write_data;
     dc->vmsd = &vmstate_smbus_eeprom;
     /* Reason: init_data */
     dc->user_creatable = false;
 }

 static const TypeInfo smbus_eeprom_info = {
     .name          = TYPE_SMBUS_EEPROM,
     .parent        = TYPE_SMBUS_DEVICE,
     .instance_size = sizeof(SMBusEEPROMDevice),
     .class_init    = smbus_eeprom_class_initfn,
 };

 static void smbus_eeprom_register_types(void)
 {
     type_register_static(&smbus_eeprom_info);
 }

 type_init(smbus_eeprom_register_types)

 void smbus_eeprom_init_one(I2CBus *smbus, uint8_t address, uint8_t *eeprom_buf)
 {
     DeviceState *dev;

     dev = qdev_new(TYPE_SMBUS_EEPROM);
     qdev_prop_set_uint8(dev, "address", address);
     /* FIXME: use an array of byte or block backend property? */
     SMBUS_EEPROM(dev)->init_data = eeprom_buf;
     qdev_realize_and_unref(dev, (BusState *)smbus, &error_fatal);
 }

 void smbus_eeprom_init(I2CBus *smbus, int nb_eeprom,
                        const uint8_t *eeprom_spd, int eeprom_spd_size)
 {
     int i;
      /* XXX: make this persistent */

     assert(nb_eeprom <= 8);
     uint8_t *eeprom_buf = g_malloc0(8 * SMBUS_EEPROM_SIZE);
     if (eeprom_spd_size > 0) {
         memcpy(eeprom_buf, eeprom_spd, eeprom_spd_size);
     }

     for (i = 0; i < nb_eeprom; i++) {
         smbus_eeprom_init_one(smbus, 0x50 + i,
                               eeprom_buf + (i * SMBUS_EEPROM_SIZE));
     }
 }

 /* Generate SDRAM SPD EEPROM data describing a module of type and size */
 uint8_t *spd_data_generate(enum sdram_type type, ram_addr_t ram_size)
 {
     uint8_t *spd;
     uint8_t nbanks;
     uint16_t density;
     uint32_t size;
     int min_log2, max_log2, sz_log2;
     int i;

     switch (type) {
     case SDR:
         min_log2 = 2;
         max_log2 = 9;
         break;
     case DDR:
         min_log2 = 5;
         max_log2 = 12;
         break;
     case DDR2:
         min_log2 = 7;
         max_log2 = 14;
         break;
     default:
         g_assert_not_reached();
     }
     size = ram_size >> 20; /* work in terms of megabytes */
     sz_log2 = 31 - clz32(size);
     size = 1U << sz_log2;
     assert(ram_size == size * MiB);
     assert(sz_log2 >= min_log2);

     nbanks = 1;
     while (sz_log2 > max_log2 && nbanks < 8) {
         sz_log2--;
         nbanks *= 2;
     }

     assert(size == (1ULL << sz_log2) * nbanks);

     /* split to 2 banks if possible to avoid a bug in MIPS Malta firmware */
     if (nbanks == 1 && sz_log2 > min_log2) {
         sz_log2--;
         nbanks++;
     }

     density = 1ULL << (sz_log2 - 2);
     switch (type) {
     case DDR2:
         density = (density & 0xe0) | (density >> 8 & 0x1f);
         break;
     case DDR:
         density = (density & 0xf8) | (density >> 8 & 0x07);
         break;
     case SDR:
     default:
         density &= 0xff;
         break;
     }

     spd = g_malloc0(256);
     spd[0] = 128;   /* data bytes in EEPROM */
     spd[1] = 8;     /* log2 size of EEPROM */
     spd[2] = type;
     spd[3] = 13;    /* row address bits */
     spd[4] = 10;    /* column address bits */
     spd[5] = (type == DDR2 ? nbanks - 1 : nbanks);
     spd[6] = 64;    /* module data width */
                     /* reserved / data width high */
     spd[8] = 4;     /* interface voltage level */
     spd[9] = 0x25;  /* highest CAS latency */
     spd[10] = 1;    /* access time */
                     /* DIMM configuration 0 = non-ECC */
     spd[12] = 0x82; /* refresh requirements */
     spd[13] = 8;    /* primary SDRAM width */
                     /* ECC SDRAM width */
     spd[15] = (type == DDR2 ? 0 : 1); /* reserved / delay for random col rd */
     spd[16] = 12;   /* burst lengths supported */
     spd[17] = 4;    /* banks per SDRAM device */
     spd[18] = 12;   /* ~CAS latencies supported */
     spd[19] = (type == DDR2 ? 0 : 1); /* reserved / ~CS latencies supported */
     spd[20] = 2;    /* DIMM type / ~WE latencies */
     spd[21] = (type < DDR2 ? 0x20 : 0); /* module features */
                     /* memory chip features */
     spd[23] = 0x12; /* clock cycle time @ medium CAS latency */
                     /* data access time */
                     /* clock cycle time @ short CAS latency */
                     /* data access time */
     spd[27] = 20;   /* min. row precharge time */
     spd[28] = 15;   /* min. row active row delay */
     spd[29] = 20;   /* min. ~RAS to ~CAS delay */
     spd[30] = 45;   /* min. active to precharge time */
     spd[31] = density;
     spd[32] = 20;   /* addr/cmd setup time */
     spd[33] = 8;    /* addr/cmd hold time */
     spd[34] = 20;   /* data input setup time */
     spd[35] = 8;    /* data input hold time */

     /* checksum */
     for (i = 0; i < 63; i++) {
         spd[63] += spd[i];
     }
     return spd;
 }
	/*
	* QEMU SMBus EEPROM device
	*
	* Copyright (c) 2007 Arastra, Inc.
	*
	* 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 "qemu/units.h"
	#include "qapi/error.h"
	#include "hw/boards.h"
	#include "hw/i2c/i2c.h"
	#include "hw/i2c/smbus_slave.h"
	#include "hw/qdev-properties.h"
	#include "migration/vmstate.h"
	#include "hw/i2c/smbus_eeprom.h"
	#include "qom/object.h"

	//#define DEBUG

	#define TYPE_SMBUS_EEPROM "smbus-eeprom"

	OBJECT_DECLARE_SIMPLE_TYPE(SMBusEEPROMDevice, SMBUS_EEPROM)

	#define SMBUS_EEPROM_SIZE 256

	struct SMBusEEPROMDevice {
	SMBusDevice smbusdev;
	uint8_t data[SMBUS_EEPROM_SIZE];
	uint8_t *init_data;
	uint8_t offset;
	bool accessed;
	};

	static uint8_t eeprom_receive_byte(SMBusDevice *dev)
	{
	SMBusEEPROMDevice *eeprom = SMBUS_EEPROM(dev);
	uint8_t *data = eeprom->data;
	uint8_t val = data[eeprom->offset++];

	eeprom->accessed = true;
	#ifdef DEBUG
	printf("eeprom_receive_byte: addr=0x%02x val=0x%02x\n",
	dev->i2c.address, val);
	#endif
	return val;
	}

	static int eeprom_write_data(SMBusDevice dev, uint8_t buf, uint8_t len)
	{
	SMBusEEPROMDevice *eeprom = SMBUS_EEPROM(dev);
	uint8_t *data = eeprom->data;

	eeprom->accessed = true;
	#ifdef DEBUG
	printf("eeprom_write_byte: addr=0x%02x cmd=0x%02x val=0x%02x\n",
	dev->i2c.address, buf[0], buf[1]);
	#endif
	/* len is guaranteed to be > 0 */
	eeprom->offset = buf[0];
	buf++;
	len--;

	for (; len > 0; len--) {
	data[eeprom->offset] = *buf++;
	eeprom->offset = (eeprom->offset + 1) % SMBUS_EEPROM_SIZE;
	}

	return 0;
	}

	static bool smbus_eeprom_vmstate_needed(void *opaque)
	{
	MachineClass *mc = MACHINE_GET_CLASS(qdev_get_machine());
	SMBusEEPROMDevice *eeprom = opaque;

	return (eeprom->accessed \|\| smbus_vmstate_needed(&eeprom->smbusdev)) &&
	!mc->smbus_no_migration_support;
	}

	static const VMStateDescription vmstate_smbus_eeprom = {
	.name = "smbus-eeprom",
	.version_id = 1,
	.minimum_version_id = 1,
	.needed = smbus_eeprom_vmstate_needed,
	.fields = (const VMStateField[]) {
	VMSTATE_SMBUS_DEVICE(smbusdev, SMBusEEPROMDevice),
	VMSTATE_UINT8_ARRAY(data, SMBusEEPROMDevice, SMBUS_EEPROM_SIZE),
	VMSTATE_UINT8(offset, SMBusEEPROMDevice),
	VMSTATE_BOOL(accessed, SMBusEEPROMDevice),
	VMSTATE_END_OF_LIST()
	}
	};

	/*
	* Reset the EEPROM contents to the initial state on a reset. This
	* isn't really how an EEPROM works, of course, but the general
	* principle of QEMU is to restore function on reset to what it would
	* be if QEMU was stopped and started.
	*
	* The proper thing to do would be to have a backing blockdev to hold
	* the contents and restore that on startup, and not do this on reset.
	* But until that time, act as if we had been stopped and restarted.
	*/
	static void smbus_eeprom_reset(DeviceState *dev)
	{
	SMBusEEPROMDevice *eeprom = SMBUS_EEPROM(dev);

	memcpy(eeprom->data, eeprom->init_data, SMBUS_EEPROM_SIZE);
	eeprom->offset = 0;
	}

	static void smbus_eeprom_realize(DeviceState dev, Error *errp)
	{
	SMBusEEPROMDevice *eeprom = SMBUS_EEPROM(dev);

	smbus_eeprom_reset(dev);
	if (eeprom->init_data == NULL) {
	error_setg(errp, "init_data cannot be NULL");
	}
	}

	static void smbus_eeprom_class_initfn(ObjectClass klass, void data)
	{
	DeviceClass *dc = DEVICE_CLASS(klass);
	SMBusDeviceClass *sc = SMBUS_DEVICE_CLASS(klass);

	dc->realize = smbus_eeprom_realize;
	device_class_set_legacy_reset(dc, smbus_eeprom_reset);
	sc->receive_byte = eeprom_receive_byte;
	sc->write_data = eeprom_write_data;
	dc->vmsd = &vmstate_smbus_eeprom;
	/* Reason: init_data */
	dc->user_creatable = false;
	}

	static const TypeInfo smbus_eeprom_info = {
	.name = TYPE_SMBUS_EEPROM,
	.parent = TYPE_SMBUS_DEVICE,
	.instance_size = sizeof(SMBusEEPROMDevice),
	.class_init = smbus_eeprom_class_initfn,
	};

	static void smbus_eeprom_register_types(void)
	{
	type_register_static(&smbus_eeprom_info);
	}

	type_init(smbus_eeprom_register_types)

	void smbus_eeprom_init_one(I2CBus smbus, uint8_t address, uint8_t eeprom_buf)
	{
	DeviceState *dev;

	dev = qdev_new(TYPE_SMBUS_EEPROM);
	qdev_prop_set_uint8(dev, "address", address);
	/* FIXME: use an array of byte or block backend property? */
	SMBUS_EEPROM(dev)->init_data = eeprom_buf;
	qdev_realize_and_unref(dev, (BusState *)smbus, &error_fatal);
	}

	void smbus_eeprom_init(I2CBus *smbus, int nb_eeprom,
	const uint8_t *eeprom_spd, int eeprom_spd_size)
	{
	int i;
	/* XXX: make this persistent */

	assert(nb_eeprom <= 8);
	uint8_t eeprom_buf = g_malloc0(8 SMBUS_EEPROM_SIZE);
	if (eeprom_spd_size > 0) {
	memcpy(eeprom_buf, eeprom_spd, eeprom_spd_size);
	}

	for (i = 0; i < nb_eeprom; i++) {
	smbus_eeprom_init_one(smbus, 0x50 + i,
	eeprom_buf + (i * SMBUS_EEPROM_SIZE));
	}
	}

	/* Generate SDRAM SPD EEPROM data describing a module of type and size */
	uint8_t *spd_data_generate(enum sdram_type type, ram_addr_t ram_size)
	{
	uint8_t *spd;
	uint8_t nbanks;
	uint16_t density;
	uint32_t size;
	int min_log2, max_log2, sz_log2;
	int i;

	switch (type) {
	case SDR:
	min_log2 = 2;
	max_log2 = 9;
	break;
	case DDR:
	min_log2 = 5;
	max_log2 = 12;
	break;
	case DDR2:
	min_log2 = 7;
	max_log2 = 14;
	break;
	default:
	g_assert_not_reached();
	}
	size = ram_size >> 20; /* work in terms of megabytes */
	sz_log2 = 31 - clz32(size);
	size = 1U << sz_log2;
	assert(ram_size == size * MiB);
	assert(sz_log2 >= min_log2);

	nbanks = 1;
	while (sz_log2 > max_log2 && nbanks < 8) {
	sz_log2--;
	nbanks *= 2;
	}

	assert(size == (1ULL << sz_log2) * nbanks);

	/* split to 2 banks if possible to avoid a bug in MIPS Malta firmware */
	if (nbanks == 1 && sz_log2 > min_log2) {
	sz_log2--;
	nbanks++;
	}

	density = 1ULL << (sz_log2 - 2);
	switch (type) {
	case DDR2:
	density = (density & 0xe0) \| (density >> 8 & 0x1f);
	break;
	case DDR:
	density = (density & 0xf8) \| (density >> 8 & 0x07);
	break;
	case SDR:
	default:
	density &= 0xff;
	break;
	}

	spd = g_malloc0(256);
	spd[0] = 128; /* data bytes in EEPROM */
	spd[1] = 8; /* log2 size of EEPROM */
	spd[2] = type;
	spd[3] = 13; /* row address bits */
	spd[4] = 10; /* column address bits */
	spd[5] = (type == DDR2 ? nbanks - 1 : nbanks);
	spd[6] = 64; /* module data width */
	/* reserved / data width high */
	spd[8] = 4; /* interface voltage level */
	spd[9] = 0x25; /* highest CAS latency */
	spd[10] = 1; /* access time */
	/* DIMM configuration 0 = non-ECC */
	spd[12] = 0x82; /* refresh requirements */
	spd[13] = 8; /* primary SDRAM width */
	/* ECC SDRAM width */
	spd[15] = (type == DDR2 ? 0 : 1); /* reserved / delay for random col rd */
	spd[16] = 12; /* burst lengths supported */
	spd[17] = 4; /* banks per SDRAM device */
	spd[18] = 12; /* ~CAS latencies supported */
	spd[19] = (type == DDR2 ? 0 : 1); /* reserved / ~CS latencies supported */
	spd[20] = 2; /* DIMM type / ~WE latencies */
	spd[21] = (type < DDR2 ? 0x20 : 0); /* module features */
	/* memory chip features */
	spd[23] = 0x12; /* clock cycle time @ medium CAS latency */
	/* data access time */
	/* clock cycle time @ short CAS latency */
	/* data access time */
	spd[27] = 20; /* min. row precharge time */
	spd[28] = 15; /* min. row active row delay */
	spd[29] = 20; /* min. ~RAS to ~CAS delay */
	spd[30] = 45; /* min. active to precharge time */
	spd[31] = density;
	spd[32] = 20; /* addr/cmd setup time */
	spd[33] = 8; /* addr/cmd hold time */
	spd[34] = 20; /* data input setup time */
	spd[35] = 8; /* data input hold time */

	/* checksum */
	for (i = 0; i < 63; i++) {
	spd[63] += spd[i];
	}
	return spd;
	}