summaryrefslogtreecommitdiffstats
path: root/drivers/hwmon/pmbus/tda38640.c
blob: c31889a036f01eefac6621796efb8e4bbcbecf13 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
// SPDX-License-Identifier: GPL-2.0+
/*
 * Hardware monitoring driver for Infineon TDA38640
 *
 * Copyright (c) 2023 9elements GmbH
 *
 */

#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/regulator/driver.h>
#include "pmbus.h"

static const struct regulator_desc __maybe_unused tda38640_reg_desc[] = {
	PMBUS_REGULATOR_ONE("vout"),
};

struct tda38640_data {
	struct pmbus_driver_info info;
	u32 en_pin_lvl;
};

#define to_tda38640_data(x)  container_of(x, struct tda38640_data, info)

/*
 * Map PB_ON_OFF_CONFIG_POLARITY_HIGH to PB_OPERATION_CONTROL_ON.
 */
static int tda38640_read_byte_data(struct i2c_client *client, int page, int reg)
{
	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
	struct tda38640_data *data = to_tda38640_data(info);
	int ret, on_off_config, enabled;

	if (reg != PMBUS_OPERATION)
		return -ENODATA;

	ret = pmbus_read_byte_data(client, page, reg);
	if (ret < 0)
		return ret;

	on_off_config = pmbus_read_byte_data(client, page,
					     PMBUS_ON_OFF_CONFIG);
	if (on_off_config < 0)
		return on_off_config;

	enabled = !!(on_off_config & PB_ON_OFF_CONFIG_POLARITY_HIGH);

	enabled ^= data->en_pin_lvl;
	if (enabled)
		ret &= ~PB_OPERATION_CONTROL_ON;
	else
		ret |= PB_OPERATION_CONTROL_ON;

	return ret;
}

/*
 * Map PB_OPERATION_CONTROL_ON to PB_ON_OFF_CONFIG_POLARITY_HIGH.
 */
static int tda38640_write_byte_data(struct i2c_client *client, int page,
				    int reg, u8 byte)
{
	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
	struct tda38640_data *data = to_tda38640_data(info);
	int enable, ret;

	if (reg != PMBUS_OPERATION)
		return -ENODATA;

	enable = !!(byte & PB_OPERATION_CONTROL_ON);

	byte &= ~PB_OPERATION_CONTROL_ON;
	ret = pmbus_write_byte_data(client, page, reg, byte);
	if (ret < 0)
		return ret;

	enable ^= data->en_pin_lvl;

	return pmbus_update_byte_data(client, page, PMBUS_ON_OFF_CONFIG,
				      PB_ON_OFF_CONFIG_POLARITY_HIGH,
				      enable ? 0 : PB_ON_OFF_CONFIG_POLARITY_HIGH);
}

static int svid_mode(struct i2c_client *client, struct tda38640_data *data)
{
	/* PMBUS_MFR_READ(0xD0) + MTP Address offset */
	u8 write_buf[] = {0xd0, 0x44, 0x00};
	u8 read_buf[2];
	int ret, svid;
	bool off, reg_en_pin_pol;

	struct i2c_msg msgs[2] = {
		{
			.addr = client->addr,
			.flags = 0,
			.buf = write_buf,
			.len = sizeof(write_buf),
		},
		{
			.addr = client->addr,
			.flags = I2C_M_RD,
			.buf = read_buf,
			.len = sizeof(read_buf),
		}
	};

	ret = i2c_transfer(client->adapter, msgs, 2);
	if (ret < 0) {
		dev_err(&client->dev, "i2c_transfer failed. %d", ret);
		return ret;
	}

	/*
	 * 0x44[15] determines PMBus Operating Mode
	 * If bit is set then it is SVID mode.
	 */
	svid = !!(read_buf[1] & BIT(7));

	/*
	 * Determine EN pin level for use in SVID mode.
	 * This is done with help of STATUS_BYTE bit 6(OFF) & ON_OFF_CONFIG bit 2(EN pin polarity).
	 */
	if (svid) {
		ret = i2c_smbus_read_byte_data(client, PMBUS_STATUS_BYTE);
		if (ret < 0)
			return ret;
		off = !!(ret & PB_STATUS_OFF);

		ret = i2c_smbus_read_byte_data(client, PMBUS_ON_OFF_CONFIG);
		if (ret < 0)
			return ret;
		reg_en_pin_pol = !!(ret & PB_ON_OFF_CONFIG_POLARITY_HIGH);
		data->en_pin_lvl = off ^ reg_en_pin_pol;
	}

	return svid;
}

static struct pmbus_driver_info tda38640_info = {
	.pages = 1,
	.format[PSC_VOLTAGE_IN] = linear,
	.format[PSC_VOLTAGE_OUT] = linear,
	.format[PSC_CURRENT_OUT] = linear,
	.format[PSC_CURRENT_IN] = linear,
	.format[PSC_POWER] = linear,
	.format[PSC_TEMPERATURE] = linear,
	.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
	    | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP
	    | PMBUS_HAVE_IIN
	    | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
	    | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
	    | PMBUS_HAVE_POUT | PMBUS_HAVE_PIN,
#if IS_ENABLED(CONFIG_SENSORS_TDA38640_REGULATOR)
	.num_regulators = 1,
	.reg_desc = tda38640_reg_desc,
#endif
};

static int tda38640_probe(struct i2c_client *client)
{
	struct tda38640_data *data;
	int svid;

	data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;
	memcpy(&data->info, &tda38640_info, sizeof(tda38640_info));

	if (IS_ENABLED(CONFIG_SENSORS_TDA38640_REGULATOR) &&
	    of_property_read_bool(client->dev.of_node, "infineon,en-pin-fixed-level")) {
		svid = svid_mode(client, data);
		if (svid < 0) {
			dev_err_probe(&client->dev, svid, "Could not determine operating mode.");
			return svid;
		}

		/*
		 * Apply ON_OFF_CONFIG workaround as enabling the regulator using the
		 * OPERATION register doesn't work in SVID mode.
		 *
		 * One should configure PMBUS_ON_OFF_CONFIG here, but
		 * PB_ON_OFF_CONFIG_POWERUP_CONTROL and PB_ON_OFF_CONFIG_EN_PIN_REQ
		 * are ignored by the device.
		 * Only PB_ON_OFF_CONFIG_POLARITY_HIGH has an effect.
		 */
		if (svid) {
			data->info.read_byte_data = tda38640_read_byte_data;
			data->info.write_byte_data = tda38640_write_byte_data;
		}
	}
	return pmbus_do_probe(client, &data->info);
}

static const struct i2c_device_id tda38640_id[] = {
	{"tda38640", 0},
	{}
};
MODULE_DEVICE_TABLE(i2c, tda38640_id);

static const struct of_device_id __maybe_unused tda38640_of_match[] = {
	{ .compatible = "infineon,tda38640"},
	{ },
};
MODULE_DEVICE_TABLE(of, tda38640_of_match);

/* This is the driver that will be inserted */
static struct i2c_driver tda38640_driver = {
	.driver = {
		.name = "tda38640",
		.of_match_table = of_match_ptr(tda38640_of_match),
	},
	.probe = tda38640_probe,
	.id_table = tda38640_id,
};

module_i2c_driver(tda38640_driver);

MODULE_AUTHOR("Patrick Rudolph <patrick.rudolph@9elements.com>");
MODULE_DESCRIPTION("PMBus driver for Infineon TDA38640");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS(PMBUS);