1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * Congatec Board Controller I2C busses driver
9 #include <linux/i2c.h>
15 #define CGBC_I2C_PRIMARY_BUS_ID	0
18 #define CGBC_I2C_CMD_START	0x40
19 #define CGBC_I2C_CMD_STAT	0x48
20 #define CGBC_I2C_CMD_DATA	0x50
21 #define CGBC_I2C_CMD_SPEED	0x58
23 #define CGBC_I2C_STAT_IDL	0x00
24 #define CGBC_I2C_STAT_DAT	0x01
25 #define CGBC_I2C_STAT_BUSY	0x02
27 #define CGBC_I2C_START	0x80
28 #define CGBC_I2C_STOP	0x40
30 #define CGBC_I2C_LAST_ACK  0x80    /* send ACK on last read byte */
41 #define CGBC_I2C_FREQ_UNIT_1KHZ		0x40
42 #define CGBC_I2C_FREQ_UNIT_10KHZ	0x80
43 #define CGBC_I2C_FREQ_UNIT_100KHZ	0xC0
45 #define CGBC_I2C_FREQ_UNIT_MASK		0xC0
46 #define CGBC_I2C_FREQ_VALUE_MASK	0x3F
55 	CGBC_I2C_STATE_DONE = 0,
118 	struct i2c_algo_cgbc_data *algo_data = adap->algo_data;  in cgbc_i2c_get_status()
119 	struct cgbc_i2c_data *i2c = i2c_get_adapdata(adap);  in cgbc_i2c_get_status()  local
120 	struct cgbc_device_data *cgbc = i2c->cgbc;  in cgbc_i2c_get_status()
121 	u8 cmd = CGBC_I2C_CMD_STAT | algo_data->bus_id;  in cgbc_i2c_get_status()
125 	ret = cgbc_command(cgbc, &cmd, sizeof(cmd), NULL, 0, &status);  in cgbc_i2c_get_status()
135 	struct i2c_algo_cgbc_data *algo_data = adap->algo_data;  in cgbc_i2c_set_frequency()
136 	struct cgbc_i2c_data *i2c = i2c_get_adapdata(adap);  in cgbc_i2c_set_frequency()  local
137 	struct cgbc_device_data *cgbc = i2c->cgbc;  in cgbc_i2c_set_frequency()
143 		dev_info(i2c->dev, "invalid frequency %u, using default\n", bus_frequency);  in cgbc_i2c_set_frequency()
147 	cmd[0] = CGBC_I2C_CMD_SPEED | algo_data->bus_id;  in cgbc_i2c_set_frequency()
152 		return dev_err_probe(i2c->dev, ret,  in cgbc_i2c_set_frequency()
153 				     "Failed to initialize I2C bus %s",  in cgbc_i2c_set_frequency()
154 				     adap->name);  in cgbc_i2c_set_frequency()
156 	cmd[1] = 0x00;  in cgbc_i2c_set_frequency()
160 		return dev_err_probe(i2c->dev, ret,  in cgbc_i2c_set_frequency()
161 				     "Failed to get I2C bus frequency");  in cgbc_i2c_set_frequency()
165 	dev_dbg(i2c->dev, "%s is running at %d Hz\n", adap->name, bus_frequency);  in cgbc_i2c_set_frequency()
173 	algo_data->read_maxtime_us = (BITS_PER_BYTE + 1) * CGBC_I2C_READ_MAX_LEN  in cgbc_i2c_set_frequency()
176 	return 0;  in cgbc_i2c_set_frequency()
181 	int i = 0;  in cgbc_i2c_xfer_to_cmd()
185 	cmd[i] = (xfer.start) ? CGBC_I2C_START : 0x00;  in cgbc_i2c_xfer_to_cmd()
195 	if (xfer.write > 0)  in cgbc_i2c_xfer_to_cmd()
203 	struct i2c_algo_cgbc_data *algo_data = adap->algo_data;  in cgbc_i2c_xfer_msg()
204 	struct cgbc_i2c_data *i2c = i2c_get_adapdata(adap);  in cgbc_i2c_xfer_msg()  local
205 	struct cgbc_device_data *cgbc = i2c->cgbc;  in cgbc_i2c_xfer_msg()
206 	struct i2c_msg *msg = i2c->msg;  in cgbc_i2c_xfer_msg()
213 		.bus_id = algo_data->bus_id,  in cgbc_i2c_xfer_msg()
217 	if (i2c->state == CGBC_I2C_STATE_DONE)  in cgbc_i2c_xfer_msg()
218 		return 0;  in cgbc_i2c_xfer_msg()
223 		return -EBUSY;  in cgbc_i2c_xfer_msg()
224 	else if (ret < 0)  in cgbc_i2c_xfer_msg()
227 	if (i2c->state == CGBC_I2C_STATE_INIT ||  in cgbc_i2c_xfer_msg()
228 	    (i2c->state == CGBC_I2C_STATE_WRITE && msg->flags & I2C_M_RD))  in cgbc_i2c_xfer_msg()
231 	i2c->state = (msg->flags & I2C_M_RD) ? CGBC_I2C_STATE_READ : CGBC_I2C_STATE_WRITE;  in cgbc_i2c_xfer_msg()
233 	max_len = (i2c->state == CGBC_I2C_STATE_READ) ?  in cgbc_i2c_xfer_msg()
236 	if (msg->len - i2c->pos > max_len) {  in cgbc_i2c_xfer_msg()
239 		len = msg->len - i2c->pos;  in cgbc_i2c_xfer_msg()
241 		if (i2c->nmsgs == 1)  in cgbc_i2c_xfer_msg()
245 	if (i2c->state == CGBC_I2C_STATE_WRITE) {  in cgbc_i2c_xfer_msg()
247 		xfer.read = 0;  in cgbc_i2c_xfer_msg()
249 		for (i = 0; i < len; i++)  in cgbc_i2c_xfer_msg()
250 			xfer.data[i] = msg->buf[i2c->pos + i];  in cgbc_i2c_xfer_msg()
252 		cmd_len = cgbc_i2c_xfer_to_cmd(xfer, &cmd[0]);  in cgbc_i2c_xfer_msg()
254 		ret = cgbc_command(cgbc, &cmd, cmd_len, NULL, 0, NULL);  in cgbc_i2c_xfer_msg()
257 	} else if (i2c->state == CGBC_I2C_STATE_READ) {  in cgbc_i2c_xfer_msg()
258 		xfer.write = 0;  in cgbc_i2c_xfer_msg()
261 		if (i2c->nmsgs > 1 || msg->len - i2c->pos > max_len)  in cgbc_i2c_xfer_msg()
264 		cmd_len = cgbc_i2c_xfer_to_cmd(xfer, &cmd[0]);  in cgbc_i2c_xfer_msg()
265 		ret = cgbc_command(cgbc, &cmd, cmd_len, NULL, 0, NULL);  in cgbc_i2c_xfer_msg()
270 					ret != CGBC_I2C_STAT_BUSY, 0,  in cgbc_i2c_xfer_msg()
271 					2 * algo_data->read_maxtime_us, false, adap);  in cgbc_i2c_xfer_msg()
272 		if (ret < 0)  in cgbc_i2c_xfer_msg()
275 		cmd_data = CGBC_I2C_CMD_DATA | algo_data->bus_id;  in cgbc_i2c_xfer_msg()
277 				   msg->buf + i2c->pos, len, NULL);  in cgbc_i2c_xfer_msg()
282 	if (len == (msg->len - i2c->pos)) {  in cgbc_i2c_xfer_msg()
283 		i2c->msg++;  in cgbc_i2c_xfer_msg()
284 		i2c->nmsgs--;  in cgbc_i2c_xfer_msg()
285 		i2c->pos = 0;  in cgbc_i2c_xfer_msg()
287 		i2c->pos += len;  in cgbc_i2c_xfer_msg()
290 	if (i2c->nmsgs == 0)  in cgbc_i2c_xfer_msg()
291 		i2c->state = CGBC_I2C_STATE_DONE;  in cgbc_i2c_xfer_msg()
293 	return 0;  in cgbc_i2c_xfer_msg()
296 	i2c->state = CGBC_I2C_STATE_ERROR;  in cgbc_i2c_xfer_msg()
303 	struct cgbc_i2c_data *i2c = i2c_get_adapdata(adap);  in cgbc_i2c_xfer()  local
307 	i2c->state = CGBC_I2C_STATE_INIT;  in cgbc_i2c_xfer()
308 	i2c->msg = msgs;  in cgbc_i2c_xfer()
309 	i2c->nmsgs = num;  in cgbc_i2c_xfer()
310 	i2c->pos = 0;  in cgbc_i2c_xfer()
314 		if (i2c->state == CGBC_I2C_STATE_DONE)  in cgbc_i2c_xfer()
317 		if (i2c->state == CGBC_I2C_STATE_ERROR)  in cgbc_i2c_xfer()
320 		if (ret == 0)  in cgbc_i2c_xfer()
324 	i2c->state = CGBC_I2C_STATE_ERROR;  in cgbc_i2c_xfer()
325 	return -ETIMEDOUT;  in cgbc_i2c_xfer()
346 		.name		= "Congatec General Purpose I2C adapter",
349 		.algo_data	= &cgbc_i2c_algo_data[0],
350 		.nr		= -1,
354 		.name		= "Congatec Power Management I2C adapter",
358 		.nr		= -1,
364 	struct cgbc_device_data *cgbc = dev_get_drvdata(pdev->dev.parent);  in cgbc_i2c_probe()
365 	struct cgbc_i2c_data *i2c;  in cgbc_i2c_probe()  local
368 	i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);  in cgbc_i2c_probe()
369 	if (!i2c)  in cgbc_i2c_probe()
370 		return -ENOMEM;  in cgbc_i2c_probe()
372 	i2c->cgbc = cgbc;  in cgbc_i2c_probe()
373 	i2c->dev = &pdev->dev;  in cgbc_i2c_probe()
374 	i2c->adap = cgbc_i2c_adapter[pdev->id];  in cgbc_i2c_probe()
375 	i2c->adap.dev.parent = i2c->dev;  in cgbc_i2c_probe()
376 	i2c_set_adapdata(&i2c->adap, i2c);  in cgbc_i2c_probe()
377 	platform_set_drvdata(pdev, i2c);  in cgbc_i2c_probe()
379 	ret = cgbc_i2c_set_frequency(&i2c->adap, I2C_MAX_STANDARD_MODE_FREQ);  in cgbc_i2c_probe()
383 	return i2c_add_numbered_adapter(&i2c->adap);  in cgbc_i2c_probe()
388 	struct cgbc_i2c_data *i2c = platform_get_drvdata(pdev);  in cgbc_i2c_remove()  local
390 	i2c_del_adapter(&i2c->adap);  in cgbc_i2c_remove()
395 		.name = "cgbc-i2c",
403 MODULE_DESCRIPTION("Congatec Board Controller I2C Driver");