1 // SPDX-License-Identifier: GPL-2.0-only
4  *  - Based on i2c-piix4.c
5  *  Copyright (c) 1998 - 2002 Frodo Looijaard <[email protected]> and
7  *  - Intel SCH support
8  *  Copyright (c) 2007 - 2008 Jacob Jun Pan <[email protected]>
50 static int backbone_speed = 33000; /* backbone speed in kHz */
52 MODULE_PARM_DESC(backbone_speed, "Backbone speed in kHz, (default = 33000)");
56 	return ioread8(priv->smba + offset);  in sch_io_rd8()
61 	iowrite8(value, priv->smba + offset);  in sch_io_wr8()
66 	return ioread16(priv->smba + offset);  in sch_io_rd16()
71 	iowrite16(value, priv->smba + offset);  in sch_io_wr16()
75  * sch_transaction - Start the i2c transaction
89 	dev_dbg(&adap->dev,  in sch_transaction()
100 			dev_dbg(&adap->dev, "Completion (%02x). Clear...\n", temp);  in sch_transaction()
102 			dev_dbg(&adap->dev, "SMBus error (%02x). Resetting...\n", temp);  in sch_transaction()
106 			dev_err(&adap->dev, "SMBus is not ready: (%02x)\n", temp);  in sch_transaction()
107 			return -EAGAIN;  in sch_transaction()
119 		dev_err(&adap->dev, "SMBus Timeout!\n");  in sch_transaction()
121 		rc = -EIO;  in sch_transaction()
122 		dev_dbg(&adap->dev, "Bus collision! SMBus may be locked until next hard reset. (sorry!)\n");  in sch_transaction()
123 		/* Clock stops and target is stuck in mid-transmission */  in sch_transaction()
125 		rc = -EIO;  in sch_transaction()
126 		dev_err(&adap->dev, "Error: no response!\n");  in sch_transaction()
128 		dev_dbg(&adap->dev, "Post complete!\n");  in sch_transaction()
133 			dev_dbg(&adap->dev,  in sch_transaction()
137 		rc = -ENXIO;  in sch_transaction()
138 		dev_dbg(&adap->dev, "No such address.\n");  in sch_transaction()
140 	dev_dbg(&adap->dev, "Transaction (post): CNT=%02x, CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",  in sch_transaction()
148  * sch_access - the main access entry for i2c-sch access
169 		dev_dbg(&adap->dev, "SMBus busy (%02x)\n", temp);  in sch_access()
170 		return -EAGAIN;  in sch_access()
180 		dev_notice(&adap->dev, "Clock divider uninitialized. Setting defaults\n");  in sch_access()
184 	dev_dbg(&adap->dev, "access size: %d %s\n", size, str_read_write(read_write));  in sch_access()
200 			sch_io_wr8(priv, SMBHSTDAT0, data->byte);  in sch_access()
207 			sch_io_wr8(priv, SMBHSTDAT0, data->word >> 0);  in sch_access()
208 			sch_io_wr8(priv, SMBHSTDAT1, data->word >> 8);  in sch_access()
216 			len = data->block[0];  in sch_access()
218 				return -EINVAL;  in sch_access()
221 				sch_io_wr8(priv, SMBBLKDAT + i - 1, data->block[i]);  in sch_access()
226 		dev_warn(&adap->dev, "Unsupported transaction %d\n", size);  in sch_access()
227 		return -EOPNOTSUPP;  in sch_access()
229 	dev_dbg(&adap->dev, "write size %d to 0x%04x\n", size, SMBHSTCNT);  in sch_access()
245 		data->byte = sch_io_rd8(priv, SMBHSTDAT0);  in sch_access()
248 		data->word = (sch_io_rd8(priv, SMBHSTDAT0) << 0) +  in sch_access()
252 		data->block[0] = sch_io_rd8(priv, SMBHSTDAT0);  in sch_access()
253 		if (data->block[0] == 0 || data->block[0] > I2C_SMBUS_BLOCK_MAX)  in sch_access()
254 			return -EPROTO;  in sch_access()
255 		for (i = 1; i <= data->block[0]; i++)  in sch_access()
256 			data->block[i] = sch_io_rd8(priv, SMBBLKDAT + i - 1);  in sch_access()
276 	struct device *dev = &pdev->dev;  in smbus_sch_probe()
282 		return -ENOMEM;  in smbus_sch_probe()
286 		return -EBUSY;  in smbus_sch_probe()
288 	priv->smba = devm_ioport_map(dev, res->start, resource_size(res));  in smbus_sch_probe()
289 	if (!priv->smba)  in smbus_sch_probe()
290 		return dev_err_probe(dev, -EBUSY, "SMBus region %pR already in use!\n", res);  in smbus_sch_probe()
293 	priv->adapter.dev.parent = dev;  in smbus_sch_probe()
294 	priv->adapter.owner = THIS_MODULE;  in smbus_sch_probe()
295 	priv->adapter.class = I2C_CLASS_HWMON;  in smbus_sch_probe()
296 	priv->adapter.algo = &smbus_algorithm;  in smbus_sch_probe()
298 	snprintf(priv->adapter.name, sizeof(priv->adapter.name),  in smbus_sch_probe()
299 		 "SMBus SCH adapter at %04x", (unsigned short)res->start);  in smbus_sch_probe()
301 	return devm_i2c_add_adapter(dev, &priv->adapter);  in smbus_sch_probe()