mp2925.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Hardware monitoring driver for MPS Multi-phase Digital VR Controllers(MP2925)
  4 */
  5
  6#include <linux/bitfield.h>
  7#include <linux/i2c.h>
  8#include <linux/module.h>
  9#include <linux/of_device.h>
 10#include "pmbus.h"
 11
 12/*
 13 * Vender specific register MFR_VR_MULTI_CONFIG(0x08).
 14 * This register is used to obtain vid scale.
 15 */
 16#define MFR_VR_MULTI_CONFIG	0x08
 17
 18#define MP2925_VOUT_DIV	512
 19#define MP2925_VOUT_OVUV_UINT	195
 20#define MP2925_VOUT_OVUV_DIV	100
 21
 22#define MP2925_PAGE_NUM	2
 23
 24#define MP2925_RAIL1_FUNC	(PMBUS_HAVE_VIN | PMBUS_HAVE_PIN | \
 25							 PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT | \
 26							 PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP | \
 27							 PMBUS_HAVE_STATUS_VOUT | \
 28							 PMBUS_HAVE_STATUS_IOUT | \
 29							 PMBUS_HAVE_STATUS_TEMP | \
 30							 PMBUS_HAVE_STATUS_INPUT)
 31
 32#define MP2925_RAIL2_FUNC	(PMBUS_HAVE_PIN | PMBUS_HAVE_VOUT | \
 33							 PMBUS_HAVE_IOUT | PMBUS_HAVE_POUT | \
 34							 PMBUS_HAVE_TEMP | PMBUS_HAVE_IIN | \
 35							 PMBUS_HAVE_STATUS_VOUT | \
 36							 PMBUS_HAVE_STATUS_IOUT | \
 37							 PMBUS_HAVE_STATUS_TEMP | \
 38							 PMBUS_HAVE_STATUS_INPUT)
 39
 40struct mp2925_data {
 41	struct pmbus_driver_info info;
 42	int vout_scale[MP2925_PAGE_NUM];
 43};
 44
 45#define to_mp2925_data(x) container_of(x, struct mp2925_data, info)
 46
 47static u16 mp2925_linear_exp_transfer(u16 word, u16 expect_exponent)
 48{
 49	s16 exponent, mantissa, target_exponent;
 50
 51	exponent = ((s16)word) >> 11;
 52	mantissa = ((s16)((word & 0x7ff) << 5)) >> 5;
 53	target_exponent = (s16)((expect_exponent & 0x1f) << 11) >> 11;
 54
 55	if (exponent > target_exponent)
 56		mantissa = mantissa << (exponent - target_exponent);
 57	else
 58		mantissa = mantissa >> (target_exponent - exponent);
 59
 60	return (mantissa & 0x7ff) | ((expect_exponent << 11) & 0xf800);
 61}
 62
 63static int mp2925_read_byte_data(struct i2c_client *client, int page, int reg)
 64{
 65	int ret;
 66
 67	switch (reg) {
 68	case PMBUS_VOUT_MODE:
 69		/*
 70		 * The MP2925 does not follow standard PMBus protocol completely,
 71		 * and the calculation of vout in this driver is based on direct
 72		 * format. As a result, the format of vout is enforced to direct.
 73		 */
 74		ret = PB_VOUT_MODE_DIRECT;
 75		break;
 76	default:
 77		ret = -ENODATA;
 78		break;
 79	}
 80
 81	return ret;
 82}
 83
 84static int mp2925_read_word_data(struct i2c_client *client, int page, int phase,
 85				 int reg)
 86{
 87	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 88	struct mp2925_data *data = to_mp2925_data(info);
 89	int ret;
 90
 91	switch (reg) {
 92	case PMBUS_READ_VOUT:
 93		ret = pmbus_read_word_data(client, page, phase, reg);
 94		if (ret < 0)
 95			return ret;
 96
 97		ret = DIV_ROUND_CLOSEST((ret & GENMASK(11, 0)) * data->vout_scale[page],
 98					MP2925_VOUT_DIV);
 99		break;
100	case PMBUS_VOUT_OV_FAULT_LIMIT:
101	case PMBUS_VOUT_UV_FAULT_LIMIT:
102		ret = pmbus_read_word_data(client, page, phase, reg);
103		if (ret < 0)
104			return ret;
105
106		ret = DIV_ROUND_CLOSEST((ret & GENMASK(11, 0)) * MP2925_VOUT_OVUV_UINT,
107					MP2925_VOUT_OVUV_DIV);
108		break;
109	case PMBUS_STATUS_WORD:
110	case PMBUS_READ_VIN:
111	case PMBUS_READ_IOUT:
112	case PMBUS_READ_POUT:
113	case PMBUS_READ_PIN:
114	case PMBUS_READ_IIN:
115	case PMBUS_READ_TEMPERATURE_1:
116	case PMBUS_VIN_OV_FAULT_LIMIT:
117	case PMBUS_VIN_OV_WARN_LIMIT:
118	case PMBUS_VIN_UV_WARN_LIMIT:
119	case PMBUS_VIN_UV_FAULT_LIMIT:
120	case PMBUS_IOUT_OC_FAULT_LIMIT:
121	case PMBUS_IOUT_OC_WARN_LIMIT:
122	case PMBUS_OT_FAULT_LIMIT:
123	case PMBUS_OT_WARN_LIMIT:
124		ret = -ENODATA;
125		break;
126	default:
127		ret = -EINVAL;
128		break;
129	}
130
131	return ret;
132}
133
134static int mp2925_write_word_data(struct i2c_client *client, int page, int reg,
135				  u16 word)
136{
137	int ret;
138
139	switch (reg) {
140	case PMBUS_VIN_OV_FAULT_LIMIT:
141	case PMBUS_VIN_OV_WARN_LIMIT:
142	case PMBUS_VIN_UV_WARN_LIMIT:
143	case PMBUS_VIN_UV_FAULT_LIMIT:
144		/*
145		 * The PMBUS_VIN_OV_FAULT_LIMIT, PMBUS_VIN_OV_WARN_LIMIT,
146		 * PMBUS_VIN_UV_WARN_LIMIT and PMBUS_VIN_UV_FAULT_LIMIT
147		 * of MP2925 is linear11 format, and the exponent is a
148		 * constant value(5'b11100)， so the exponent of word
149		 * parameter should be converted to 5'b11100(0x1C).
150		 */
151		ret = pmbus_write_word_data(client, page, reg,
152					    mp2925_linear_exp_transfer(word, 0x1C));
153		break;
154	case PMBUS_VOUT_OV_FAULT_LIMIT:
155	case PMBUS_VOUT_UV_FAULT_LIMIT:
156		/*
157		 * The bit0-bit11 is the limit value, and bit12-bit15
158		 * should not be changed.
159		 */
160		ret = pmbus_read_word_data(client, page, 0xff, reg);
161		if (ret < 0)
162			return ret;
163
164		ret = pmbus_write_word_data(client, page, reg,
165					    (ret & ~GENMASK(11, 0)) |
166				FIELD_PREP(GENMASK(11, 0),
167					   DIV_ROUND_CLOSEST(word * MP2925_VOUT_OVUV_DIV,
168							     MP2925_VOUT_OVUV_UINT)));
169		break;
170	case PMBUS_OT_FAULT_LIMIT:
171	case PMBUS_OT_WARN_LIMIT:
172		/*
173		 * The PMBUS_OT_FAULT_LIMIT and PMBUS_OT_WARN_LIMIT of
174		 * MP2925 is linear11 format, and the exponent is a
175		 * constant value(5'b00000), so the exponent of word
176		 * parameter should be converted to 5'b00000.
177		 */
178		ret = pmbus_write_word_data(client, page, reg,
179					    mp2925_linear_exp_transfer(word, 0x00));
180		break;
181	case PMBUS_IOUT_OC_FAULT_LIMIT:
182	case PMBUS_IOUT_OC_WARN_LIMIT:
183		/*
184		 * The PMBUS_IOUT_OC_FAULT_LIMIT and PMBUS_IOUT_OC_WARN_LIMIT
185		 * of MP2925 is linear11 format, and the exponent can not be
186		 * changed.
187		 */
188		ret = pmbus_read_word_data(client, page, 0xff, reg);
189		if (ret < 0)
190			return ret;
191
192		ret = pmbus_write_word_data(client, page, reg,
193					    mp2925_linear_exp_transfer(word,
194								       FIELD_GET(GENMASK(15, 11),
195										 ret)));
196		break;
197	default:
198		ret = -EINVAL;
199		break;
200	}
201
202	return ret;
203}
204
205static int
206mp2925_identify_vout_scale(struct i2c_client *client, struct pmbus_driver_info *info,
207			   int page)
208{
209	struct mp2925_data *data = to_mp2925_data(info);
210	int ret;
211
212	ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, page);
213	if (ret < 0)
214		return ret;
215
216	ret = i2c_smbus_read_byte_data(client, PMBUS_VOUT_MODE);
217	if (ret < 0)
218		return ret;
219
220	if (FIELD_GET(GENMASK(5, 5), ret)) {
221		ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE,
222						page == 0 ? 3 : 4);
223		if (ret < 0)
224			return ret;
225
226		ret = i2c_smbus_read_word_data(client, MFR_VR_MULTI_CONFIG);
227		if (ret < 0)
228			return ret;
229
230		if (FIELD_GET(GENMASK(5, 5), ret))
231			data->vout_scale[page] = 2560;
232		else
233			data->vout_scale[page] = 5120;
234	} else if (FIELD_GET(GENMASK(4, 4), ret)) {
235		data->vout_scale[page] = 1;
236	} else {
237		data->vout_scale[page] = 512;
238	}
239
240	return 0;
241}
242
243static int mp2925_identify(struct i2c_client *client, struct pmbus_driver_info *info)
244{
245	int ret;
246
247	ret = mp2925_identify_vout_scale(client, info, 0);
248	if (ret < 0)
249		return ret;
250
251	return mp2925_identify_vout_scale(client, info, 1);
252}
253
254static const struct pmbus_driver_info mp2925_info = {
255	.pages = MP2925_PAGE_NUM,
256	.format[PSC_VOLTAGE_IN] = linear,
257	.format[PSC_CURRENT_IN] = linear,
258	.format[PSC_CURRENT_OUT] = linear,
259	.format[PSC_POWER] = linear,
260	.format[PSC_TEMPERATURE] = linear,
261	.format[PSC_VOLTAGE_OUT] = direct,
262
263	.m[PSC_VOLTAGE_OUT] = 1,
264	.R[PSC_VOLTAGE_OUT] = 3,
265	.b[PSC_VOLTAGE_OUT] = 0,
266
267	.func[0] = MP2925_RAIL1_FUNC,
268	.func[1] = MP2925_RAIL2_FUNC,
269	.read_word_data = mp2925_read_word_data,
270	.read_byte_data = mp2925_read_byte_data,
271	.write_word_data = mp2925_write_word_data,
272	.identify = mp2925_identify,
273};
274
275static int mp2925_probe(struct i2c_client *client)
276{
277	struct mp2925_data *data;
278
279	data = devm_kzalloc(&client->dev, sizeof(struct mp2925_data), GFP_KERNEL);
280	if (!data)
281		return -ENOMEM;
282
283	memcpy(&data->info, &mp2925_info, sizeof(mp2925_info));
284
285	return pmbus_do_probe(client, &data->info);
286}
287
288static const struct i2c_device_id mp2925_id[] = {
289	{"mp2925"},
290	{"mp2929"},
291	{}
292};
293MODULE_DEVICE_TABLE(i2c, mp2925_id);
294
295static const struct of_device_id __maybe_unused mp2925_of_match[] = {
296	{.compatible = "mps,mp2925"},
297	{.compatible = "mps,mp2929"},
298	{}
299};
300MODULE_DEVICE_TABLE(of, mp2925_of_match);
301
302static struct i2c_driver mp2925_driver = {
303	.driver = {
304		.name = "mp2925",
305		.of_match_table = mp2925_of_match,
306	},
307	.probe = mp2925_probe,
308	.id_table = mp2925_id,
309};
310
311module_i2c_driver(mp2925_driver);
312
313MODULE_AUTHOR("Wensheng Wang <wenswang@yeah.net>");
314MODULE_DESCRIPTION("PMBus driver for MPS MP2925");
315MODULE_LICENSE("GPL");
316MODULE_IMPORT_NS("PMBUS");