1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Hardware monitoring driver for Infineon TDA38640
4 *
5 * Copyright (c) 2023 9elements GmbH
6 *
7 */
8
9 #include <linux/err.h>
10 #include <linux/i2c.h>
11 #include <linux/init.h>
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/regulator/driver.h>
15 #include "pmbus.h"
16
17 static const struct regulator_desc __maybe_unused tda38640_reg_desc[] = {
18 PMBUS_REGULATOR_ONE("vout"),
19 };
20
21 struct tda38640_data {
22 struct pmbus_driver_info info;
23 u32 en_pin_lvl;
24 };
25
26 #define to_tda38640_data(x) container_of(x, struct tda38640_data, info)
27
28 /*
29 * Map PB_ON_OFF_CONFIG_POLARITY_HIGH to PB_OPERATION_CONTROL_ON.
30 */
tda38640_read_byte_data(struct i2c_client * client,int page,int reg)31 static int tda38640_read_byte_data(struct i2c_client *client, int page, int reg)
32 {
33 const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
34 struct tda38640_data *data = to_tda38640_data(info);
35 int ret, on_off_config, enabled;
36
37 if (reg != PMBUS_OPERATION)
38 return -ENODATA;
39
40 ret = pmbus_read_byte_data(client, page, reg);
41 if (ret < 0)
42 return ret;
43
44 on_off_config = pmbus_read_byte_data(client, page,
45 PMBUS_ON_OFF_CONFIG);
46 if (on_off_config < 0)
47 return on_off_config;
48
49 enabled = !!(on_off_config & PB_ON_OFF_CONFIG_POLARITY_HIGH);
50
51 enabled ^= data->en_pin_lvl;
52 if (enabled)
53 ret &= ~PB_OPERATION_CONTROL_ON;
54 else
55 ret |= PB_OPERATION_CONTROL_ON;
56
57 return ret;
58 }
59
60 /*
61 * Map PB_OPERATION_CONTROL_ON to PB_ON_OFF_CONFIG_POLARITY_HIGH.
62 */
tda38640_write_byte_data(struct i2c_client * client,int page,int reg,u8 byte)63 static int tda38640_write_byte_data(struct i2c_client *client, int page,
64 int reg, u8 byte)
65 {
66 const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
67 struct tda38640_data *data = to_tda38640_data(info);
68 int enable, ret;
69
70 if (reg != PMBUS_OPERATION)
71 return -ENODATA;
72
73 enable = !!(byte & PB_OPERATION_CONTROL_ON);
74
75 byte &= ~PB_OPERATION_CONTROL_ON;
76 ret = pmbus_write_byte_data(client, page, reg, byte);
77 if (ret < 0)
78 return ret;
79
80 enable ^= data->en_pin_lvl;
81
82 return pmbus_update_byte_data(client, page, PMBUS_ON_OFF_CONFIG,
83 PB_ON_OFF_CONFIG_POLARITY_HIGH,
84 enable ? 0 : PB_ON_OFF_CONFIG_POLARITY_HIGH);
85 }
86
svid_mode(struct i2c_client * client,struct tda38640_data * data)87 static int svid_mode(struct i2c_client *client, struct tda38640_data *data)
88 {
89 /* PMBUS_MFR_READ(0xD0) + MTP Address offset */
90 u8 write_buf[] = {0xd0, 0x44, 0x00};
91 u8 read_buf[2];
92 int ret, svid;
93 bool off, reg_en_pin_pol;
94
95 struct i2c_msg msgs[2] = {
96 {
97 .addr = client->addr,
98 .flags = 0,
99 .buf = write_buf,
100 .len = sizeof(write_buf),
101 },
102 {
103 .addr = client->addr,
104 .flags = I2C_M_RD,
105 .buf = read_buf,
106 .len = sizeof(read_buf),
107 }
108 };
109
110 ret = i2c_transfer(client->adapter, msgs, 2);
111 if (ret < 0) {
112 dev_err(&client->dev, "i2c_transfer failed. %d", ret);
113 return ret;
114 }
115
116 /*
117 * 0x44[15] determines PMBus Operating Mode
118 * If bit is set then it is SVID mode.
119 */
120 svid = !!(read_buf[1] & BIT(7));
121
122 /*
123 * Determine EN pin level for use in SVID mode.
124 * This is done with help of STATUS_BYTE bit 6(OFF) & ON_OFF_CONFIG bit 2(EN pin polarity).
125 */
126 if (svid) {
127 ret = i2c_smbus_read_byte_data(client, PMBUS_STATUS_BYTE);
128 if (ret < 0)
129 return ret;
130 off = !!(ret & PB_STATUS_OFF);
131
132 ret = i2c_smbus_read_byte_data(client, PMBUS_ON_OFF_CONFIG);
133 if (ret < 0)
134 return ret;
135 reg_en_pin_pol = !!(ret & PB_ON_OFF_CONFIG_POLARITY_HIGH);
136 data->en_pin_lvl = off ^ reg_en_pin_pol;
137 }
138
139 return svid;
140 }
141
142 static struct pmbus_driver_info tda38640_info = {
143 .pages = 1,
144 .format[PSC_VOLTAGE_IN] = linear,
145 .format[PSC_VOLTAGE_OUT] = linear,
146 .format[PSC_CURRENT_OUT] = linear,
147 .format[PSC_CURRENT_IN] = linear,
148 .format[PSC_POWER] = linear,
149 .format[PSC_TEMPERATURE] = linear,
150 .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
151 | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP
152 | PMBUS_HAVE_IIN
153 | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
154 | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
155 | PMBUS_HAVE_POUT | PMBUS_HAVE_PIN,
156 #if IS_ENABLED(CONFIG_SENSORS_TDA38640_REGULATOR)
157 .num_regulators = 1,
158 .reg_desc = tda38640_reg_desc,
159 #endif
160 };
161
tda38640_probe(struct i2c_client * client)162 static int tda38640_probe(struct i2c_client *client)
163 {
164 struct tda38640_data *data;
165 int svid;
166
167 data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
168 if (!data)
169 return -ENOMEM;
170 memcpy(&data->info, &tda38640_info, sizeof(tda38640_info));
171
172 if (IS_ENABLED(CONFIG_SENSORS_TDA38640_REGULATOR) &&
173 of_property_read_bool(client->dev.of_node, "infineon,en-pin-fixed-level")) {
174 svid = svid_mode(client, data);
175 if (svid < 0) {
176 dev_err_probe(&client->dev, svid, "Could not determine operating mode.");
177 return svid;
178 }
179
180 /*
181 * Apply ON_OFF_CONFIG workaround as enabling the regulator using the
182 * OPERATION register doesn't work in SVID mode.
183 *
184 * One should configure PMBUS_ON_OFF_CONFIG here, but
185 * PB_ON_OFF_CONFIG_POWERUP_CONTROL and PB_ON_OFF_CONFIG_EN_PIN_REQ
186 * are ignored by the device.
187 * Only PB_ON_OFF_CONFIG_POLARITY_HIGH has an effect.
188 */
189 if (svid) {
190 data->info.read_byte_data = tda38640_read_byte_data;
191 data->info.write_byte_data = tda38640_write_byte_data;
192 }
193 }
194 return pmbus_do_probe(client, &data->info);
195 }
196
197 static const struct i2c_device_id tda38640_id[] = {
198 {"tda38640"},
199 {}
200 };
201 MODULE_DEVICE_TABLE(i2c, tda38640_id);
202
203 static const struct of_device_id __maybe_unused tda38640_of_match[] = {
204 { .compatible = "infineon,tda38640"},
205 { },
206 };
207 MODULE_DEVICE_TABLE(of, tda38640_of_match);
208
209 /* This is the driver that will be inserted */
210 static struct i2c_driver tda38640_driver = {
211 .driver = {
212 .name = "tda38640",
213 .of_match_table = of_match_ptr(tda38640_of_match),
214 },
215 .probe = tda38640_probe,
216 .id_table = tda38640_id,
217 };
218
219 module_i2c_driver(tda38640_driver);
220
221 MODULE_AUTHOR("Patrick Rudolph <patrick.rudolph@9elements.com>");
222 MODULE_DESCRIPTION("PMBus driver for Infineon TDA38640");
223 MODULE_LICENSE("GPL");
224 MODULE_IMPORT_NS(PMBUS);
225