cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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i2c-sis5595.c (11200B)


      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3    Copyright (c) 1998, 1999  Frodo Looijaard <frodol@dds.nl> and
      4    Philip Edelbrock <phil@netroedge.com>
      5
      6*/
      7
      8/* Note: we assume there can only be one SIS5595 with one SMBus interface */
      9
     10/*
     11   Note: all have mfr. ID 0x1039.
     12   SUPPORTED		PCI ID		
     13	5595		0008
     14
     15   Note: these chips contain a 0008 device which is incompatible with the
     16         5595. We recognize these by the presence of the listed
     17         "blacklist" PCI ID and refuse to load.
     18
     19   NOT SUPPORTED	PCI ID		BLACKLIST PCI ID	
     20	 540		0008		0540
     21	 550		0008		0550
     22	5513		0008		5511
     23	5581		0008		5597
     24	5582		0008		5597
     25	5597		0008		5597
     26	5598		0008		5597/5598
     27	 630		0008		0630
     28	 645		0008		0645
     29	 646		0008		0646
     30	 648		0008		0648
     31	 650		0008		0650
     32	 651		0008		0651
     33	 730		0008		0730
     34	 735		0008		0735
     35	 745		0008		0745
     36	 746		0008		0746
     37*/
     38
     39/* TO DO: 
     40 * Add Block Transfers (ugly, but supported by the adapter)
     41 * Add adapter resets
     42 */
     43
     44#include <linux/kernel.h>
     45#include <linux/module.h>
     46#include <linux/delay.h>
     47#include <linux/pci.h>
     48#include <linux/ioport.h>
     49#include <linux/init.h>
     50#include <linux/i2c.h>
     51#include <linux/acpi.h>
     52#include <linux/io.h>
     53
     54static int blacklist[] = {
     55	PCI_DEVICE_ID_SI_540,
     56	PCI_DEVICE_ID_SI_550,
     57	PCI_DEVICE_ID_SI_630,
     58	PCI_DEVICE_ID_SI_645,
     59	PCI_DEVICE_ID_SI_646,
     60	PCI_DEVICE_ID_SI_648,
     61	PCI_DEVICE_ID_SI_650,
     62	PCI_DEVICE_ID_SI_651,
     63	PCI_DEVICE_ID_SI_730,
     64	PCI_DEVICE_ID_SI_735,
     65	PCI_DEVICE_ID_SI_745,
     66	PCI_DEVICE_ID_SI_746,
     67	PCI_DEVICE_ID_SI_5511,	/* 5513 chip has the 0008 device but that ID
     68				   shows up in other chips so we use the 5511
     69				   ID for recognition */
     70	PCI_DEVICE_ID_SI_5597,
     71	PCI_DEVICE_ID_SI_5598,
     72	0,			/* terminates the list */
     73};
     74
     75/* Length of ISA address segment */
     76#define SIS5595_EXTENT		8
     77/* SIS5595 SMBus registers */
     78#define SMB_STS_LO		0x00
     79#define SMB_STS_HI		0x01
     80#define SMB_CTL_LO		0x02
     81#define SMB_CTL_HI		0x03
     82#define SMB_ADDR		0x04
     83#define SMB_CMD			0x05
     84#define SMB_PCNT		0x06
     85#define SMB_CNT			0x07
     86#define SMB_BYTE		0x08
     87#define SMB_DEV			0x10
     88#define SMB_DB0			0x11
     89#define SMB_DB1			0x12
     90#define SMB_HAA			0x13
     91
     92/* PCI Address Constants */
     93#define SMB_INDEX		0x38
     94#define SMB_DAT			0x39
     95#define SIS5595_ENABLE_REG	0x40
     96#define ACPI_BASE		0x90
     97
     98/* Other settings */
     99#define MAX_TIMEOUT		500
    100
    101/* SIS5595 constants */
    102#define SIS5595_QUICK		0x00
    103#define SIS5595_BYTE		0x02
    104#define SIS5595_BYTE_DATA	0x04
    105#define SIS5595_WORD_DATA	0x06
    106#define SIS5595_PROC_CALL	0x08
    107#define SIS5595_BLOCK_DATA	0x0A
    108
    109/* insmod parameters */
    110
    111/* If force_addr is set to anything different from 0, we forcibly enable
    112   the device at the given address. */
    113static u16 force_addr;
    114module_param_hw(force_addr, ushort, ioport, 0);
    115MODULE_PARM_DESC(force_addr, "Initialize the base address of the i2c controller");
    116
    117static struct pci_driver sis5595_driver;
    118static unsigned short sis5595_base;
    119static struct pci_dev *sis5595_pdev;
    120
    121static u8 sis5595_read(u8 reg)
    122{
    123	outb(reg, sis5595_base + SMB_INDEX);
    124	return inb(sis5595_base + SMB_DAT);
    125}
    126
    127static void sis5595_write(u8 reg, u8 data)
    128{
    129	outb(reg, sis5595_base + SMB_INDEX);
    130	outb(data, sis5595_base + SMB_DAT);
    131}
    132
    133static int sis5595_setup(struct pci_dev *SIS5595_dev)
    134{
    135	u16 a;
    136	u8 val;
    137	int *i;
    138	int retval;
    139
    140	/* Look for imposters */
    141	for (i = blacklist; *i != 0; i++) {
    142		struct pci_dev *dev;
    143		dev = pci_get_device(PCI_VENDOR_ID_SI, *i, NULL);
    144		if (dev) {
    145			dev_err(&SIS5595_dev->dev, "Looked for SIS5595 but found unsupported device %.4x\n", *i);
    146			pci_dev_put(dev);
    147			return -ENODEV;
    148		}
    149	}
    150
    151	/* Determine the address of the SMBus areas */
    152	pci_read_config_word(SIS5595_dev, ACPI_BASE, &sis5595_base);
    153	if (sis5595_base == 0 && force_addr == 0) {
    154		dev_err(&SIS5595_dev->dev, "ACPI base address uninitialized - upgrade BIOS or use force_addr=0xaddr\n");
    155		return -ENODEV;
    156	}
    157
    158	if (force_addr)
    159		sis5595_base = force_addr & ~(SIS5595_EXTENT - 1);
    160	dev_dbg(&SIS5595_dev->dev, "ACPI Base address: %04x\n", sis5595_base);
    161
    162	/* NB: We grab just the two SMBus registers here, but this may still
    163	 * interfere with ACPI :-(  */
    164	retval = acpi_check_region(sis5595_base + SMB_INDEX, 2,
    165				   sis5595_driver.name);
    166	if (retval)
    167		return retval;
    168
    169	if (!request_region(sis5595_base + SMB_INDEX, 2,
    170			    sis5595_driver.name)) {
    171		dev_err(&SIS5595_dev->dev, "SMBus registers 0x%04x-0x%04x already in use!\n",
    172			sis5595_base + SMB_INDEX, sis5595_base + SMB_INDEX + 1);
    173		return -ENODEV;
    174	}
    175
    176	if (force_addr) {
    177		dev_info(&SIS5595_dev->dev, "forcing ISA address 0x%04X\n", sis5595_base);
    178		if (pci_write_config_word(SIS5595_dev, ACPI_BASE, sis5595_base)
    179		    != PCIBIOS_SUCCESSFUL)
    180			goto error;
    181		if (pci_read_config_word(SIS5595_dev, ACPI_BASE, &a)
    182		    != PCIBIOS_SUCCESSFUL)
    183			goto error;
    184		if ((a & ~(SIS5595_EXTENT - 1)) != sis5595_base) {
    185			/* doesn't work for some chips! */
    186			dev_err(&SIS5595_dev->dev, "force address failed - not supported?\n");
    187			goto error;
    188		}
    189	}
    190
    191	if (pci_read_config_byte(SIS5595_dev, SIS5595_ENABLE_REG, &val)
    192	    != PCIBIOS_SUCCESSFUL)
    193		goto error;
    194	if ((val & 0x80) == 0) {
    195		dev_info(&SIS5595_dev->dev, "enabling ACPI\n");
    196		if (pci_write_config_byte(SIS5595_dev, SIS5595_ENABLE_REG, val | 0x80)
    197		    != PCIBIOS_SUCCESSFUL)
    198			goto error;
    199		if (pci_read_config_byte(SIS5595_dev, SIS5595_ENABLE_REG, &val)
    200		    != PCIBIOS_SUCCESSFUL)
    201			goto error;
    202		if ((val & 0x80) == 0) {
    203			/* doesn't work for some chips? */
    204			dev_err(&SIS5595_dev->dev, "ACPI enable failed - not supported?\n");
    205			goto error;
    206		}
    207	}
    208
    209	/* Everything is happy */
    210	return 0;
    211
    212error:
    213	release_region(sis5595_base + SMB_INDEX, 2);
    214	return -ENODEV;
    215}
    216
    217static int sis5595_transaction(struct i2c_adapter *adap)
    218{
    219	int temp;
    220	int result = 0;
    221	int timeout = 0;
    222
    223	/* Make sure the SMBus host is ready to start transmitting */
    224	temp = sis5595_read(SMB_STS_LO) + (sis5595_read(SMB_STS_HI) << 8);
    225	if (temp != 0x00) {
    226		dev_dbg(&adap->dev, "SMBus busy (%04x). Resetting...\n", temp);
    227		sis5595_write(SMB_STS_LO, temp & 0xff);
    228		sis5595_write(SMB_STS_HI, temp >> 8);
    229		if ((temp = sis5595_read(SMB_STS_LO) + (sis5595_read(SMB_STS_HI) << 8)) != 0x00) {
    230			dev_dbg(&adap->dev, "Failed! (%02x)\n", temp);
    231			return -EBUSY;
    232		} else {
    233			dev_dbg(&adap->dev, "Successful!\n");
    234		}
    235	}
    236
    237	/* start the transaction by setting bit 4 */
    238	sis5595_write(SMB_CTL_LO, sis5595_read(SMB_CTL_LO) | 0x10);
    239
    240	/* We will always wait for a fraction of a second! */
    241	do {
    242		msleep(1);
    243		temp = sis5595_read(SMB_STS_LO);
    244	} while (!(temp & 0x40) && (timeout++ < MAX_TIMEOUT));
    245
    246	/* If the SMBus is still busy, we give up */
    247	if (timeout > MAX_TIMEOUT) {
    248		dev_dbg(&adap->dev, "SMBus Timeout!\n");
    249		result = -ETIMEDOUT;
    250	}
    251
    252	if (temp & 0x10) {
    253		dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
    254		result = -ENXIO;
    255	}
    256
    257	if (temp & 0x20) {
    258		dev_err(&adap->dev, "Bus collision! SMBus may be locked until "
    259			"next hard reset (or not...)\n");
    260		/* Clock stops and slave is stuck in mid-transmission */
    261		result = -EIO;
    262	}
    263
    264	temp = sis5595_read(SMB_STS_LO) + (sis5595_read(SMB_STS_HI) << 8);
    265	if (temp != 0x00) {
    266		sis5595_write(SMB_STS_LO, temp & 0xff);
    267		sis5595_write(SMB_STS_HI, temp >> 8);
    268	}
    269
    270	temp = sis5595_read(SMB_STS_LO) + (sis5595_read(SMB_STS_HI) << 8);
    271	if (temp != 0x00)
    272		dev_dbg(&adap->dev, "Failed reset at end of transaction (%02x)\n", temp);
    273
    274	return result;
    275}
    276
    277/* Return negative errno on error. */
    278static s32 sis5595_access(struct i2c_adapter *adap, u16 addr,
    279			  unsigned short flags, char read_write,
    280			  u8 command, int size, union i2c_smbus_data *data)
    281{
    282	int status;
    283
    284	switch (size) {
    285	case I2C_SMBUS_QUICK:
    286		sis5595_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
    287		size = SIS5595_QUICK;
    288		break;
    289	case I2C_SMBUS_BYTE:
    290		sis5595_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
    291		if (read_write == I2C_SMBUS_WRITE)
    292			sis5595_write(SMB_CMD, command);
    293		size = SIS5595_BYTE;
    294		break;
    295	case I2C_SMBUS_BYTE_DATA:
    296		sis5595_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
    297		sis5595_write(SMB_CMD, command);
    298		if (read_write == I2C_SMBUS_WRITE)
    299			sis5595_write(SMB_BYTE, data->byte);
    300		size = SIS5595_BYTE_DATA;
    301		break;
    302	case I2C_SMBUS_PROC_CALL:
    303	case I2C_SMBUS_WORD_DATA:
    304		sis5595_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
    305		sis5595_write(SMB_CMD, command);
    306		if (read_write == I2C_SMBUS_WRITE) {
    307			sis5595_write(SMB_BYTE, data->word & 0xff);
    308			sis5595_write(SMB_BYTE + 1,
    309				      (data->word & 0xff00) >> 8);
    310		}
    311		size = (size == I2C_SMBUS_PROC_CALL) ? SIS5595_PROC_CALL : SIS5595_WORD_DATA;
    312		break;
    313	default:
    314		dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
    315		return -EOPNOTSUPP;
    316	}
    317
    318	sis5595_write(SMB_CTL_LO, ((size & 0x0E)));
    319
    320	status = sis5595_transaction(adap);
    321	if (status)
    322		return status;
    323
    324	if ((size != SIS5595_PROC_CALL) &&
    325	    ((read_write == I2C_SMBUS_WRITE) || (size == SIS5595_QUICK)))
    326		return 0;
    327
    328
    329	switch (size) {
    330	case SIS5595_BYTE:
    331	case SIS5595_BYTE_DATA:
    332		data->byte = sis5595_read(SMB_BYTE);
    333		break;
    334	case SIS5595_WORD_DATA:
    335	case SIS5595_PROC_CALL:
    336		data->word = sis5595_read(SMB_BYTE) + (sis5595_read(SMB_BYTE + 1) << 8);
    337		break;
    338	}
    339	return 0;
    340}
    341
    342static u32 sis5595_func(struct i2c_adapter *adapter)
    343{
    344	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
    345	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
    346	    I2C_FUNC_SMBUS_PROC_CALL;
    347}
    348
    349static const struct i2c_algorithm smbus_algorithm = {
    350	.smbus_xfer	= sis5595_access,
    351	.functionality	= sis5595_func,
    352};
    353
    354static struct i2c_adapter sis5595_adapter = {
    355	.owner		= THIS_MODULE,
    356	.class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
    357	.algo		= &smbus_algorithm,
    358};
    359
    360static const struct pci_device_id sis5595_ids[] = {
    361	{ PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_503) }, 
    362	{ 0, }
    363};
    364
    365MODULE_DEVICE_TABLE (pci, sis5595_ids);
    366
    367static int sis5595_probe(struct pci_dev *dev, const struct pci_device_id *id)
    368{
    369	int err;
    370
    371	if (sis5595_setup(dev)) {
    372		dev_err(&dev->dev, "SIS5595 not detected, module not inserted.\n");
    373		return -ENODEV;
    374	}
    375
    376	/* set up the sysfs linkage to our parent device */
    377	sis5595_adapter.dev.parent = &dev->dev;
    378
    379	snprintf(sis5595_adapter.name, sizeof(sis5595_adapter.name),
    380		 "SMBus SIS5595 adapter at %04x", sis5595_base + SMB_INDEX);
    381	err = i2c_add_adapter(&sis5595_adapter);
    382	if (err) {
    383		release_region(sis5595_base + SMB_INDEX, 2);
    384		return err;
    385	}
    386
    387	/* Always return failure here.  This is to allow other drivers to bind
    388	 * to this pci device.  We don't really want to have control over the
    389	 * pci device, we only wanted to read as few register values from it.
    390	 */
    391	sis5595_pdev =  pci_dev_get(dev);
    392	return -ENODEV;
    393}
    394
    395static struct pci_driver sis5595_driver = {
    396	.name		= "sis5595_smbus",
    397	.id_table	= sis5595_ids,
    398	.probe		= sis5595_probe,
    399};
    400
    401static int __init i2c_sis5595_init(void)
    402{
    403	return pci_register_driver(&sis5595_driver);
    404}
    405
    406static void __exit i2c_sis5595_exit(void)
    407{
    408	pci_unregister_driver(&sis5595_driver);
    409	if (sis5595_pdev) {
    410		i2c_del_adapter(&sis5595_adapter);
    411		release_region(sis5595_base + SMB_INDEX, 2);
    412		pci_dev_put(sis5595_pdev);
    413		sis5595_pdev = NULL;
    414	}
    415}
    416
    417MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
    418MODULE_DESCRIPTION("SIS5595 SMBus driver");
    419MODULE_LICENSE("GPL");
    420
    421module_init(i2c_sis5595_init);
    422module_exit(i2c_sis5595_exit);