1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * ADM1177 Hot Swap Controller and Digital Power Monitor with Soft Start Pin |
4 | * |
5 | * Copyright 2015-2019 Analog Devices Inc. |
6 | */ |
7 | |
8 | #include <linux/bits.h> |
9 | #include <linux/device.h> |
10 | #include <linux/hwmon.h> |
11 | #include <linux/i2c.h> |
12 | #include <linux/init.h> |
13 | #include <linux/module.h> |
14 | #include <linux/regulator/consumer.h> |
15 | |
16 | /* Command Byte Operations */ |
17 | #define ADM1177_CMD_V_CONT BIT(0) |
18 | #define ADM1177_CMD_I_CONT BIT(2) |
19 | #define ADM1177_CMD_VRANGE BIT(4) |
20 | |
21 | /* Extended Register */ |
22 | #define ADM1177_REG_ALERT_TH 2 |
23 | |
24 | #define ADM1177_BITS 12 |
25 | |
26 | /** |
27 | * struct adm1177_state - driver instance specific data |
28 | * @client: pointer to i2c client |
29 | * @r_sense_uohm: current sense resistor value |
30 | * @alert_threshold_ua: current limit for shutdown |
31 | * @vrange_high: internal voltage divider |
32 | */ |
33 | struct adm1177_state { |
34 | struct i2c_client *client; |
35 | u32 r_sense_uohm; |
36 | u32 alert_threshold_ua; |
37 | bool vrange_high; |
38 | }; |
39 | |
40 | static int adm1177_read_raw(struct adm1177_state *st, u8 num, u8 *data) |
41 | { |
42 | return i2c_master_recv(client: st->client, buf: data, count: num); |
43 | } |
44 | |
45 | static int adm1177_write_cmd(struct adm1177_state *st, u8 cmd) |
46 | { |
47 | return i2c_smbus_write_byte(client: st->client, value: cmd); |
48 | } |
49 | |
50 | static int adm1177_write_alert_thr(struct adm1177_state *st, |
51 | u32 alert_threshold_ua) |
52 | { |
53 | u64 val; |
54 | int ret; |
55 | |
56 | val = 0xFFULL * alert_threshold_ua * st->r_sense_uohm; |
57 | val = div_u64(dividend: val, divisor: 105840000U); |
58 | val = div_u64(dividend: val, divisor: 1000U); |
59 | if (val > 0xFF) |
60 | val = 0xFF; |
61 | |
62 | ret = i2c_smbus_write_byte_data(client: st->client, ADM1177_REG_ALERT_TH, |
63 | value: val); |
64 | if (ret) |
65 | return ret; |
66 | |
67 | st->alert_threshold_ua = alert_threshold_ua; |
68 | return 0; |
69 | } |
70 | |
71 | static int adm1177_read(struct device *dev, enum hwmon_sensor_types type, |
72 | u32 attr, int channel, long *val) |
73 | { |
74 | struct adm1177_state *st = dev_get_drvdata(dev); |
75 | u8 data[3]; |
76 | long dummy; |
77 | int ret; |
78 | |
79 | switch (type) { |
80 | case hwmon_curr: |
81 | switch (attr) { |
82 | case hwmon_curr_input: |
83 | ret = adm1177_read_raw(st, num: 3, data); |
84 | if (ret < 0) |
85 | return ret; |
86 | dummy = (data[1] << 4) | (data[2] & 0xF); |
87 | /* |
88 | * convert to milliamperes |
89 | * ((105.84mV / 4096) x raw) / senseResistor(ohm) |
90 | */ |
91 | *val = div_u64(dividend: (105840000ull * dummy), |
92 | divisor: 4096 * st->r_sense_uohm); |
93 | return 0; |
94 | case hwmon_curr_max_alarm: |
95 | *val = st->alert_threshold_ua; |
96 | return 0; |
97 | default: |
98 | return -EOPNOTSUPP; |
99 | } |
100 | case hwmon_in: |
101 | ret = adm1177_read_raw(st, num: 3, data); |
102 | if (ret < 0) |
103 | return ret; |
104 | dummy = (data[0] << 4) | (data[2] >> 4); |
105 | /* |
106 | * convert to millivolts based on resistor devision |
107 | * (V_fullscale / 4096) * raw |
108 | */ |
109 | if (st->vrange_high) |
110 | dummy *= 26350; |
111 | else |
112 | dummy *= 6650; |
113 | |
114 | *val = DIV_ROUND_CLOSEST(dummy, 4096); |
115 | return 0; |
116 | default: |
117 | return -EOPNOTSUPP; |
118 | } |
119 | } |
120 | |
121 | static int adm1177_write(struct device *dev, enum hwmon_sensor_types type, |
122 | u32 attr, int channel, long val) |
123 | { |
124 | struct adm1177_state *st = dev_get_drvdata(dev); |
125 | |
126 | switch (type) { |
127 | case hwmon_curr: |
128 | switch (attr) { |
129 | case hwmon_curr_max_alarm: |
130 | adm1177_write_alert_thr(st, alert_threshold_ua: val); |
131 | return 0; |
132 | default: |
133 | return -EOPNOTSUPP; |
134 | } |
135 | default: |
136 | return -EOPNOTSUPP; |
137 | } |
138 | } |
139 | |
140 | static umode_t adm1177_is_visible(const void *data, |
141 | enum hwmon_sensor_types type, |
142 | u32 attr, int channel) |
143 | { |
144 | const struct adm1177_state *st = data; |
145 | |
146 | switch (type) { |
147 | case hwmon_in: |
148 | switch (attr) { |
149 | case hwmon_in_input: |
150 | return 0444; |
151 | } |
152 | break; |
153 | case hwmon_curr: |
154 | switch (attr) { |
155 | case hwmon_curr_input: |
156 | if (st->r_sense_uohm) |
157 | return 0444; |
158 | return 0; |
159 | case hwmon_curr_max_alarm: |
160 | if (st->r_sense_uohm) |
161 | return 0644; |
162 | return 0; |
163 | } |
164 | break; |
165 | default: |
166 | break; |
167 | } |
168 | return 0; |
169 | } |
170 | |
171 | static const struct hwmon_channel_info * const adm1177_info[] = { |
172 | HWMON_CHANNEL_INFO(curr, |
173 | HWMON_C_INPUT | HWMON_C_MAX_ALARM), |
174 | HWMON_CHANNEL_INFO(in, |
175 | HWMON_I_INPUT), |
176 | NULL |
177 | }; |
178 | |
179 | static const struct hwmon_ops adm1177_hwmon_ops = { |
180 | .is_visible = adm1177_is_visible, |
181 | .read = adm1177_read, |
182 | .write = adm1177_write, |
183 | }; |
184 | |
185 | static const struct hwmon_chip_info adm1177_chip_info = { |
186 | .ops = &adm1177_hwmon_ops, |
187 | .info = adm1177_info, |
188 | }; |
189 | |
190 | static int adm1177_probe(struct i2c_client *client) |
191 | { |
192 | struct device *dev = &client->dev; |
193 | struct device *hwmon_dev; |
194 | struct adm1177_state *st; |
195 | u32 alert_threshold_ua; |
196 | int ret; |
197 | |
198 | st = devm_kzalloc(dev, size: sizeof(*st), GFP_KERNEL); |
199 | if (!st) |
200 | return -ENOMEM; |
201 | |
202 | st->client = client; |
203 | |
204 | ret = devm_regulator_get_enable_optional(dev: &client->dev, id: "vref" ); |
205 | if (ret == -EPROBE_DEFER) |
206 | return -EPROBE_DEFER; |
207 | |
208 | if (device_property_read_u32(dev, propname: "shunt-resistor-micro-ohms" , |
209 | val: &st->r_sense_uohm)) |
210 | st->r_sense_uohm = 0; |
211 | if (device_property_read_u32(dev, propname: "adi,shutdown-threshold-microamp" , |
212 | val: &alert_threshold_ua)) { |
213 | if (st->r_sense_uohm) |
214 | /* |
215 | * set maximum default value from datasheet based on |
216 | * shunt-resistor |
217 | */ |
218 | alert_threshold_ua = div_u64(dividend: 105840000000, |
219 | divisor: st->r_sense_uohm); |
220 | else |
221 | alert_threshold_ua = 0; |
222 | } |
223 | st->vrange_high = device_property_read_bool(dev, |
224 | propname: "adi,vrange-high-enable" ); |
225 | if (alert_threshold_ua && st->r_sense_uohm) |
226 | adm1177_write_alert_thr(st, alert_threshold_ua); |
227 | |
228 | ret = adm1177_write_cmd(st, ADM1177_CMD_V_CONT | |
229 | ADM1177_CMD_I_CONT | |
230 | (st->vrange_high ? 0 : ADM1177_CMD_VRANGE)); |
231 | if (ret) |
232 | return ret; |
233 | |
234 | hwmon_dev = |
235 | devm_hwmon_device_register_with_info(dev, name: client->name, drvdata: st, |
236 | info: &adm1177_chip_info, NULL); |
237 | return PTR_ERR_OR_ZERO(ptr: hwmon_dev); |
238 | } |
239 | |
240 | static const struct i2c_device_id adm1177_id[] = { |
241 | {"adm1177" , 0}, |
242 | {} |
243 | }; |
244 | MODULE_DEVICE_TABLE(i2c, adm1177_id); |
245 | |
246 | static const struct of_device_id adm1177_dt_ids[] = { |
247 | { .compatible = "adi,adm1177" }, |
248 | {}, |
249 | }; |
250 | MODULE_DEVICE_TABLE(of, adm1177_dt_ids); |
251 | |
252 | static struct i2c_driver adm1177_driver = { |
253 | .driver = { |
254 | .name = "adm1177" , |
255 | .of_match_table = adm1177_dt_ids, |
256 | }, |
257 | .probe = adm1177_probe, |
258 | .id_table = adm1177_id, |
259 | }; |
260 | module_i2c_driver(adm1177_driver); |
261 | |
262 | MODULE_AUTHOR("Beniamin Bia <beniamin.bia@analog.com>" ); |
263 | MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>" ); |
264 | MODULE_DESCRIPTION("Analog Devices ADM1177 ADC driver" ); |
265 | MODULE_LICENSE("GPL v2" ); |
266 | |