11802d0beSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only
25bc12008SAlek Du /*
35bc12008SAlek Du i2c-isch.c - Linux kernel driver for Intel SCH chipset SMBus
45bc12008SAlek Du - Based on i2c-piix4.c
55bc12008SAlek Du Copyright (c) 1998 - 2002 Frodo Looijaard <frodol@dds.nl> and
65bc12008SAlek Du Philip Edelbrock <phil@netroedge.com>
75bc12008SAlek Du - Intel SCH support
85bc12008SAlek Du Copyright (c) 2007 - 2008 Jacob Jun Pan <jacob.jun.pan@intel.com>
95bc12008SAlek Du
105bc12008SAlek Du */
115bc12008SAlek Du
125bc12008SAlek Du /*
135bc12008SAlek Du Supports:
145bc12008SAlek Du Intel SCH chipsets (AF82US15W, AF82US15L, AF82UL11L)
155bc12008SAlek Du Note: we assume there can only be one device, with one SMBus interface.
165bc12008SAlek Du */
175bc12008SAlek Du
185bc12008SAlek Du #include <linux/module.h>
19fd46a006SDenis Turischev #include <linux/platform_device.h>
205bc12008SAlek Du #include <linux/kernel.h>
215bc12008SAlek Du #include <linux/delay.h>
225bc12008SAlek Du #include <linux/stddef.h>
235bc12008SAlek Du #include <linux/ioport.h>
245bc12008SAlek Du #include <linux/i2c.h>
255bc12008SAlek Du #include <linux/io.h>
265bc12008SAlek Du
275bc12008SAlek Du /* SCH SMBus address offsets */
285bc12008SAlek Du #define SMBHSTCNT (0 + sch_smba)
295bc12008SAlek Du #define SMBHSTSTS (1 + sch_smba)
30b08369a1SAlexander Stein #define SMBHSTCLK (2 + sch_smba)
315bc12008SAlek Du #define SMBHSTADD (4 + sch_smba) /* TSA */
325bc12008SAlek Du #define SMBHSTCMD (5 + sch_smba)
335bc12008SAlek Du #define SMBHSTDAT0 (6 + sch_smba)
345bc12008SAlek Du #define SMBHSTDAT1 (7 + sch_smba)
355bc12008SAlek Du #define SMBBLKDAT (0x20 + sch_smba)
365bc12008SAlek Du
375bc12008SAlek Du /* Other settings */
38b3240e68SOlivier Sobrie #define MAX_RETRIES 5000
395bc12008SAlek Du
405bc12008SAlek Du /* I2C constants */
415bc12008SAlek Du #define SCH_QUICK 0x00
425bc12008SAlek Du #define SCH_BYTE 0x01
435bc12008SAlek Du #define SCH_BYTE_DATA 0x02
445bc12008SAlek Du #define SCH_WORD_DATA 0x03
455bc12008SAlek Du #define SCH_BLOCK_DATA 0x05
465bc12008SAlek Du
475bc12008SAlek Du static unsigned short sch_smba;
485bc12008SAlek Du static struct i2c_adapter sch_adapter;
49b08369a1SAlexander Stein static int backbone_speed = 33000; /* backbone speed in kHz */
50b08369a1SAlexander Stein module_param(backbone_speed, int, S_IRUSR | S_IWUSR);
51b08369a1SAlexander Stein MODULE_PARM_DESC(backbone_speed, "Backbone speed in kHz, (default = 33000)");
525bc12008SAlek Du
535bc12008SAlek Du /*
545bc12008SAlek Du * Start the i2c transaction -- the i2c_access will prepare the transaction
555bc12008SAlek Du * and this function will execute it.
565bc12008SAlek Du * return 0 for success and others for failure.
575bc12008SAlek Du */
sch_transaction(void)585bc12008SAlek Du static int sch_transaction(void)
595bc12008SAlek Du {
605bc12008SAlek Du int temp;
615bc12008SAlek Du int result = 0;
62b3240e68SOlivier Sobrie int retries = 0;
635bc12008SAlek Du
645bc12008SAlek Du dev_dbg(&sch_adapter.dev, "Transaction (pre): CNT=%02x, CMD=%02x, "
655bc12008SAlek Du "ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb(SMBHSTCNT),
665bc12008SAlek Du inb(SMBHSTCMD), inb(SMBHSTADD), inb(SMBHSTDAT0),
675bc12008SAlek Du inb(SMBHSTDAT1));
685bc12008SAlek Du
695bc12008SAlek Du /* Make sure the SMBus host is ready to start transmitting */
705bc12008SAlek Du temp = inb(SMBHSTSTS) & 0x0f;
715bc12008SAlek Du if (temp) {
725bc12008SAlek Du /* Can not be busy since we checked it in sch_access */
735bc12008SAlek Du if (temp & 0x01) {
745bc12008SAlek Du dev_dbg(&sch_adapter.dev, "Completion (%02x). "
755bc12008SAlek Du "Clear...\n", temp);
765bc12008SAlek Du }
775bc12008SAlek Du if (temp & 0x06) {
785bc12008SAlek Du dev_dbg(&sch_adapter.dev, "SMBus error (%02x). "
795bc12008SAlek Du "Resetting...\n", temp);
805bc12008SAlek Du }
815bc12008SAlek Du outb(temp, SMBHSTSTS);
825bc12008SAlek Du temp = inb(SMBHSTSTS) & 0x0f;
835bc12008SAlek Du if (temp) {
845bc12008SAlek Du dev_err(&sch_adapter.dev,
855bc12008SAlek Du "SMBus is not ready: (%02x)\n", temp);
865bc12008SAlek Du return -EAGAIN;
875bc12008SAlek Du }
885bc12008SAlek Du }
895bc12008SAlek Du
905bc12008SAlek Du /* start the transaction by setting bit 4 */
915bc12008SAlek Du outb(inb(SMBHSTCNT) | 0x10, SMBHSTCNT);
925bc12008SAlek Du
935bc12008SAlek Du do {
94b3240e68SOlivier Sobrie usleep_range(100, 200);
955bc12008SAlek Du temp = inb(SMBHSTSTS) & 0x0f;
96b3240e68SOlivier Sobrie } while ((temp & 0x08) && (retries++ < MAX_RETRIES));
975bc12008SAlek Du
985bc12008SAlek Du /* If the SMBus is still busy, we give up */
99b3240e68SOlivier Sobrie if (retries > MAX_RETRIES) {
1005bc12008SAlek Du dev_err(&sch_adapter.dev, "SMBus Timeout!\n");
1015bc12008SAlek Du result = -ETIMEDOUT;
1025bc12008SAlek Du }
1035bc12008SAlek Du if (temp & 0x04) {
1045bc12008SAlek Du result = -EIO;
1055bc12008SAlek Du dev_dbg(&sch_adapter.dev, "Bus collision! SMBus may be "
1065bc12008SAlek Du "locked until next hard reset. (sorry!)\n");
1075bc12008SAlek Du /* Clock stops and slave is stuck in mid-transmission */
1085bc12008SAlek Du } else if (temp & 0x02) {
1095bc12008SAlek Du result = -EIO;
1105bc12008SAlek Du dev_err(&sch_adapter.dev, "Error: no response!\n");
1115bc12008SAlek Du } else if (temp & 0x01) {
1125bc12008SAlek Du dev_dbg(&sch_adapter.dev, "Post complete!\n");
1135bc12008SAlek Du outb(temp, SMBHSTSTS);
1145bc12008SAlek Du temp = inb(SMBHSTSTS) & 0x07;
1155bc12008SAlek Du if (temp & 0x06) {
1165bc12008SAlek Du /* Completion clear failed */
1175bc12008SAlek Du dev_dbg(&sch_adapter.dev, "Failed reset at end of "
1185bc12008SAlek Du "transaction (%02x), Bus error!\n", temp);
1195bc12008SAlek Du }
1205bc12008SAlek Du } else {
1215bc12008SAlek Du result = -ENXIO;
1225bc12008SAlek Du dev_dbg(&sch_adapter.dev, "No such address.\n");
1235bc12008SAlek Du }
1245bc12008SAlek Du dev_dbg(&sch_adapter.dev, "Transaction (post): CNT=%02x, CMD=%02x, "
1255bc12008SAlek Du "ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb(SMBHSTCNT),
1265bc12008SAlek Du inb(SMBHSTCMD), inb(SMBHSTADD), inb(SMBHSTDAT0),
1275bc12008SAlek Du inb(SMBHSTDAT1));
1285bc12008SAlek Du return result;
1295bc12008SAlek Du }
1305bc12008SAlek Du
1315bc12008SAlek Du /*
1325bc12008SAlek Du * This is the main access entry for i2c-sch access
1335bc12008SAlek Du * adap is i2c_adapter pointer, addr is the i2c device bus address, read_write
1345bc12008SAlek Du * (0 for read and 1 for write), size is i2c transaction type and data is the
13525985edcSLucas De Marchi * union of transaction for data to be transferred or data read from bus.
1365bc12008SAlek Du * return 0 for success and others for failure.
1375bc12008SAlek Du */
sch_access(struct i2c_adapter * adap,u16 addr,unsigned short flags,char read_write,u8 command,int size,union i2c_smbus_data * data)1385bc12008SAlek Du static s32 sch_access(struct i2c_adapter *adap, u16 addr,
1395bc12008SAlek Du unsigned short flags, char read_write,
1405bc12008SAlek Du u8 command, int size, union i2c_smbus_data *data)
1415bc12008SAlek Du {
1425bc12008SAlek Du int i, len, temp, rc;
1435bc12008SAlek Du
1445bc12008SAlek Du /* Make sure the SMBus host is not busy */
1455bc12008SAlek Du temp = inb(SMBHSTSTS) & 0x0f;
1465bc12008SAlek Du if (temp & 0x08) {
1475bc12008SAlek Du dev_dbg(&sch_adapter.dev, "SMBus busy (%02x)\n", temp);
1485bc12008SAlek Du return -EAGAIN;
1495bc12008SAlek Du }
150b08369a1SAlexander Stein temp = inw(SMBHSTCLK);
151b08369a1SAlexander Stein if (!temp) {
152b08369a1SAlexander Stein /*
153b08369a1SAlexander Stein * We can't determine if we have 33 or 25 MHz clock for
154b08369a1SAlexander Stein * SMBus, so expect 33 MHz and calculate a bus clock of
155b08369a1SAlexander Stein * 100 kHz. If we actually run at 25 MHz the bus will be
156b08369a1SAlexander Stein * run ~75 kHz instead which should do no harm.
157b08369a1SAlexander Stein */
158b08369a1SAlexander Stein dev_notice(&sch_adapter.dev,
159ea51e17bSColin Ian King "Clock divider uninitialized. Setting defaults\n");
160b08369a1SAlexander Stein outw(backbone_speed / (4 * 100), SMBHSTCLK);
161b08369a1SAlexander Stein }
162b08369a1SAlexander Stein
1635bc12008SAlek Du dev_dbg(&sch_adapter.dev, "access size: %d %s\n", size,
1645bc12008SAlek Du (read_write)?"READ":"WRITE");
1655bc12008SAlek Du switch (size) {
1665bc12008SAlek Du case I2C_SMBUS_QUICK:
1675bc12008SAlek Du outb((addr << 1) | read_write, SMBHSTADD);
1685bc12008SAlek Du size = SCH_QUICK;
1695bc12008SAlek Du break;
1705bc12008SAlek Du case I2C_SMBUS_BYTE:
1715bc12008SAlek Du outb((addr << 1) | read_write, SMBHSTADD);
1725bc12008SAlek Du if (read_write == I2C_SMBUS_WRITE)
1735bc12008SAlek Du outb(command, SMBHSTCMD);
1745bc12008SAlek Du size = SCH_BYTE;
1755bc12008SAlek Du break;
1765bc12008SAlek Du case I2C_SMBUS_BYTE_DATA:
1775bc12008SAlek Du outb((addr << 1) | read_write, SMBHSTADD);
1785bc12008SAlek Du outb(command, SMBHSTCMD);
1795bc12008SAlek Du if (read_write == I2C_SMBUS_WRITE)
1805bc12008SAlek Du outb(data->byte, SMBHSTDAT0);
1815bc12008SAlek Du size = SCH_BYTE_DATA;
1825bc12008SAlek Du break;
1835bc12008SAlek Du case I2C_SMBUS_WORD_DATA:
1845bc12008SAlek Du outb((addr << 1) | read_write, SMBHSTADD);
1855bc12008SAlek Du outb(command, SMBHSTCMD);
1865bc12008SAlek Du if (read_write == I2C_SMBUS_WRITE) {
1875bc12008SAlek Du outb(data->word & 0xff, SMBHSTDAT0);
1885bc12008SAlek Du outb((data->word & 0xff00) >> 8, SMBHSTDAT1);
1895bc12008SAlek Du }
1905bc12008SAlek Du size = SCH_WORD_DATA;
1915bc12008SAlek Du break;
1925bc12008SAlek Du case I2C_SMBUS_BLOCK_DATA:
1935bc12008SAlek Du outb((addr << 1) | read_write, SMBHSTADD);
1945bc12008SAlek Du outb(command, SMBHSTCMD);
1955bc12008SAlek Du if (read_write == I2C_SMBUS_WRITE) {
1965bc12008SAlek Du len = data->block[0];
1975bc12008SAlek Du if (len == 0 || len > I2C_SMBUS_BLOCK_MAX)
1985bc12008SAlek Du return -EINVAL;
1995bc12008SAlek Du outb(len, SMBHSTDAT0);
2005bc12008SAlek Du for (i = 1; i <= len; i++)
2015bc12008SAlek Du outb(data->block[i], SMBBLKDAT+i-1);
2025bc12008SAlek Du }
2035bc12008SAlek Du size = SCH_BLOCK_DATA;
2045bc12008SAlek Du break;
2055bc12008SAlek Du default:
2065bc12008SAlek Du dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
2075bc12008SAlek Du return -EOPNOTSUPP;
2085bc12008SAlek Du }
2095bc12008SAlek Du dev_dbg(&sch_adapter.dev, "write size %d to 0x%04x\n", size, SMBHSTCNT);
2105bc12008SAlek Du outb((inb(SMBHSTCNT) & 0xb0) | (size & 0x7), SMBHSTCNT);
2115bc12008SAlek Du
2125bc12008SAlek Du rc = sch_transaction();
2135bc12008SAlek Du if (rc) /* Error in transaction */
2145bc12008SAlek Du return rc;
2155bc12008SAlek Du
2165bc12008SAlek Du if ((read_write == I2C_SMBUS_WRITE) || (size == SCH_QUICK))
2175bc12008SAlek Du return 0;
2185bc12008SAlek Du
2195bc12008SAlek Du switch (size) {
2205bc12008SAlek Du case SCH_BYTE:
2215bc12008SAlek Du case SCH_BYTE_DATA:
2225bc12008SAlek Du data->byte = inb(SMBHSTDAT0);
2235bc12008SAlek Du break;
2245bc12008SAlek Du case SCH_WORD_DATA:
2255bc12008SAlek Du data->word = inb(SMBHSTDAT0) + (inb(SMBHSTDAT1) << 8);
2265bc12008SAlek Du break;
2275bc12008SAlek Du case SCH_BLOCK_DATA:
2285bc12008SAlek Du data->block[0] = inb(SMBHSTDAT0);
2295bc12008SAlek Du if (data->block[0] == 0 || data->block[0] > I2C_SMBUS_BLOCK_MAX)
2305bc12008SAlek Du return -EPROTO;
2315bc12008SAlek Du for (i = 1; i <= data->block[0]; i++)
2325bc12008SAlek Du data->block[i] = inb(SMBBLKDAT+i-1);
2335bc12008SAlek Du break;
2345bc12008SAlek Du }
2355bc12008SAlek Du return 0;
2365bc12008SAlek Du }
2375bc12008SAlek Du
sch_func(struct i2c_adapter * adapter)2385bc12008SAlek Du static u32 sch_func(struct i2c_adapter *adapter)
2395bc12008SAlek Du {
2405bc12008SAlek Du return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
2415bc12008SAlek Du I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
2425bc12008SAlek Du I2C_FUNC_SMBUS_BLOCK_DATA;
2435bc12008SAlek Du }
2445bc12008SAlek Du
2455bc12008SAlek Du static const struct i2c_algorithm smbus_algorithm = {
2465bc12008SAlek Du .smbus_xfer = sch_access,
2475bc12008SAlek Du .functionality = sch_func,
2485bc12008SAlek Du };
2495bc12008SAlek Du
2505bc12008SAlek Du static struct i2c_adapter sch_adapter = {
2515bc12008SAlek Du .owner = THIS_MODULE,
2523401b2ffSJean Delvare .class = I2C_CLASS_HWMON | I2C_CLASS_SPD,
2535bc12008SAlek Du .algo = &smbus_algorithm,
2545bc12008SAlek Du };
2555bc12008SAlek Du
smbus_sch_probe(struct platform_device * dev)2560b255e92SBill Pemberton static int smbus_sch_probe(struct platform_device *dev)
2575bc12008SAlek Du {
258fd46a006SDenis Turischev struct resource *res;
2595bc12008SAlek Du int retval;
2605bc12008SAlek Du
261fd46a006SDenis Turischev res = platform_get_resource(dev, IORESOURCE_IO, 0);
262fd46a006SDenis Turischev if (!res)
263fd46a006SDenis Turischev return -EBUSY;
2645bc12008SAlek Du
26534d7ffa0SJingoo Han if (!devm_request_region(&dev->dev, res->start, resource_size(res),
26634d7ffa0SJingoo Han dev->name)) {
2675bc12008SAlek Du dev_err(&dev->dev, "SMBus region 0x%x already in use!\n",
2685bc12008SAlek Du sch_smba);
2695bc12008SAlek Du return -EBUSY;
2705bc12008SAlek Du }
271fd46a006SDenis Turischev
272fd46a006SDenis Turischev sch_smba = res->start;
273fd46a006SDenis Turischev
2745bc12008SAlek Du dev_dbg(&dev->dev, "SMBA = 0x%X\n", sch_smba);
2755bc12008SAlek Du
2765bc12008SAlek Du /* set up the sysfs linkage to our parent device */
2775bc12008SAlek Du sch_adapter.dev.parent = &dev->dev;
2785bc12008SAlek Du
2795bc12008SAlek Du snprintf(sch_adapter.name, sizeof(sch_adapter.name),
2805bc12008SAlek Du "SMBus SCH adapter at %04x", sch_smba);
2815bc12008SAlek Du
2825bc12008SAlek Du retval = i2c_add_adapter(&sch_adapter);
283ea734404SWolfram Sang if (retval)
2845bc12008SAlek Du sch_smba = 0;
2855bc12008SAlek Du
2865bc12008SAlek Du return retval;
2875bc12008SAlek Du }
2885bc12008SAlek Du
smbus_sch_remove(struct platform_device * pdev)289*e190a0c3SUwe Kleine-König static void smbus_sch_remove(struct platform_device *pdev)
2905bc12008SAlek Du {
2915bc12008SAlek Du if (sch_smba) {
2925bc12008SAlek Du i2c_del_adapter(&sch_adapter);
2935bc12008SAlek Du sch_smba = 0;
2945bc12008SAlek Du }
2955bc12008SAlek Du }
2965bc12008SAlek Du
297fd46a006SDenis Turischev static struct platform_driver smbus_sch_driver = {
298fd46a006SDenis Turischev .driver = {
2995bc12008SAlek Du .name = "isch_smbus",
300fd46a006SDenis Turischev },
301fd46a006SDenis Turischev .probe = smbus_sch_probe,
302*e190a0c3SUwe Kleine-König .remove_new = smbus_sch_remove,
3035bc12008SAlek Du };
3045bc12008SAlek Du
305a3664b51SAxel Lin module_platform_driver(smbus_sch_driver);
3065bc12008SAlek Du
3075bc12008SAlek Du MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@intel.com>");
3085bc12008SAlek Du MODULE_DESCRIPTION("Intel SCH SMBus driver");
3095bc12008SAlek Du MODULE_LICENSE("GPL");
310fd46a006SDenis Turischev MODULE_ALIAS("platform:isch_smbus");
311