1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // Copyright (c) 2010-2024 Analog Devices Inc.
4 // Copyright (c) 2024 Baylibre, SAS
5
6 #include <linux/bitfield.h>
7 #include <linux/device.h>
8 #include <linux/module.h>
9 #include <linux/property.h>
10 #include <linux/regulator/consumer.h>
11
12 #include "ad3552r.h"
13
14 const s32 ad3552r_ch_ranges[AD3552R_MAX_RANGES][2] = {
15 [AD3552R_CH_OUTPUT_RANGE_0__2P5V] = { 0, 2500 },
16 [AD3552R_CH_OUTPUT_RANGE_0__5V] = { 0, 5000 },
17 [AD3552R_CH_OUTPUT_RANGE_0__10V] = { 0, 10000 },
18 [AD3552R_CH_OUTPUT_RANGE_NEG_5__5V] = { -5000, 5000 },
19 [AD3552R_CH_OUTPUT_RANGE_NEG_10__10V] = { -10000, 10000 }
20 };
21 EXPORT_SYMBOL_NS_GPL(ad3552r_ch_ranges, "IIO_AD3552R");
22
23 const s32 ad3542r_ch_ranges[AD3542R_MAX_RANGES][2] = {
24 [AD3542R_CH_OUTPUT_RANGE_0__2P5V] = { 0, 2500 },
25 [AD3542R_CH_OUTPUT_RANGE_0__3V] = { 0, 3000 },
26 [AD3542R_CH_OUTPUT_RANGE_0__5V] = { 0, 5000 },
27 [AD3542R_CH_OUTPUT_RANGE_0__10V] = { 0, 10000 },
28 [AD3542R_CH_OUTPUT_RANGE_NEG_2P5__7P5V] = { -2500, 7500 },
29 [AD3542R_CH_OUTPUT_RANGE_NEG_5__5V] = { -5000, 5000 }
30 };
31 EXPORT_SYMBOL_NS_GPL(ad3542r_ch_ranges, "IIO_AD3552R");
32
33 /* Gain * AD3552R_GAIN_SCALE */
34 static const s32 gains_scaling_table[] = {
35 [AD3552R_CH_GAIN_SCALING_1] = 1000,
36 [AD3552R_CH_GAIN_SCALING_0_5] = 500,
37 [AD3552R_CH_GAIN_SCALING_0_25] = 250,
38 [AD3552R_CH_GAIN_SCALING_0_125] = 125
39 };
40
ad3552r_calc_custom_gain(u8 p,u8 n,s16 goffs)41 u16 ad3552r_calc_custom_gain(u8 p, u8 n, s16 goffs)
42 {
43 return FIELD_PREP(AD3552R_MASK_CH_RANGE_OVERRIDE, 1) |
44 FIELD_PREP(AD3552R_MASK_CH_GAIN_SCALING_P, p) |
45 FIELD_PREP(AD3552R_MASK_CH_GAIN_SCALING_N, n) |
46 FIELD_PREP(AD3552R_MASK_CH_OFFSET_BIT_8, abs(goffs)) |
47 FIELD_PREP(AD3552R_MASK_CH_OFFSET_POLARITY, goffs < 0);
48 }
49 EXPORT_SYMBOL_NS_GPL(ad3552r_calc_custom_gain, "IIO_AD3552R");
50
ad3552r_get_custom_range(struct ad3552r_ch_data * ch_data,s32 * v_min,s32 * v_max)51 static void ad3552r_get_custom_range(struct ad3552r_ch_data *ch_data,
52 s32 *v_min, s32 *v_max)
53 {
54 s64 vref, tmp, common, offset, gn, gp;
55 /*
56 * From datasheet formula (In Volts):
57 * Vmin = 2.5 + [(GainN + Offset / 1024) * 2.5 * Rfb * 1.03]
58 * Vmax = 2.5 - [(GainP + Offset / 1024) * 2.5 * Rfb * 1.03]
59 * Calculus are converted to milivolts
60 */
61 vref = 2500;
62 /* 2.5 * 1.03 * 1000 (To mV) */
63 common = 2575 * ch_data->rfb;
64 offset = ch_data->gain_offset;
65
66 gn = gains_scaling_table[ch_data->n];
67 tmp = (1024 * gn + AD3552R_GAIN_SCALE * offset) * common;
68 tmp = div_s64(tmp, 1024 * AD3552R_GAIN_SCALE);
69 *v_max = vref + tmp;
70
71 gp = gains_scaling_table[ch_data->p];
72 tmp = (1024 * gp - AD3552R_GAIN_SCALE * offset) * common;
73 tmp = div_s64(tmp, 1024 * AD3552R_GAIN_SCALE);
74 *v_min = vref - tmp;
75 }
76
ad3552r_calc_gain_and_offset(struct ad3552r_ch_data * ch_data,const struct ad3552r_model_data * model_data)77 void ad3552r_calc_gain_and_offset(struct ad3552r_ch_data *ch_data,
78 const struct ad3552r_model_data *model_data)
79 {
80 s32 idx, v_max, v_min, span, rem;
81 s64 tmp;
82
83 if (ch_data->range_override) {
84 ad3552r_get_custom_range(ch_data, &v_min, &v_max);
85 } else {
86 /* Normal range */
87 idx = ch_data->range;
88 v_min = model_data->ranges_table[idx][0];
89 v_max = model_data->ranges_table[idx][1];
90 }
91
92 /*
93 * From datasheet formula:
94 * Vout = Span * (D / 65536) + Vmin
95 * Converted to scale and offset:
96 * Scale = Span / 65536
97 * Offset = 65536 * Vmin / Span
98 *
99 * Reminders are in micros in order to be printed as
100 * IIO_VAL_INT_PLUS_MICRO
101 */
102 span = v_max - v_min;
103 ch_data->scale_int = div_s64_rem(span, 65536, &rem);
104 /* Do operations in microvolts */
105 ch_data->scale_dec = DIV_ROUND_CLOSEST((s64)rem * 1000000, 65536);
106
107 ch_data->offset_int = div_s64_rem(v_min * 65536, span, &rem);
108 tmp = (s64)rem * 1000000;
109 ch_data->offset_dec = div_s64(tmp, span);
110 }
111 EXPORT_SYMBOL_NS_GPL(ad3552r_calc_gain_and_offset, "IIO_AD3552R");
112
ad3552r_get_ref_voltage(struct device * dev,u32 * val)113 int ad3552r_get_ref_voltage(struct device *dev, u32 *val)
114 {
115 int voltage;
116 int delta = 100000;
117
118 voltage = devm_regulator_get_enable_read_voltage(dev, "vref");
119 if (voltage < 0 && voltage != -ENODEV)
120 return dev_err_probe(dev, voltage,
121 "Error getting vref voltage\n");
122
123 if (voltage == -ENODEV) {
124 if (device_property_read_bool(dev, "adi,vref-out-en"))
125 *val = AD3552R_INTERNAL_VREF_PIN_2P5V;
126 else
127 *val = AD3552R_INTERNAL_VREF_PIN_FLOATING;
128
129 return 0;
130 }
131
132 if (voltage > 2500000 + delta || voltage < 2500000 - delta) {
133 dev_warn(dev, "vref-supply must be 2.5V");
134 return -EINVAL;
135 }
136
137 *val = AD3552R_EXTERNAL_VREF_PIN_INPUT;
138
139 return 0;
140 }
141 EXPORT_SYMBOL_NS_GPL(ad3552r_get_ref_voltage, "IIO_AD3552R");
142
ad3552r_get_drive_strength(struct device * dev,u32 * val)143 int ad3552r_get_drive_strength(struct device *dev, u32 *val)
144 {
145 int err;
146 u32 drive_strength;
147
148 err = device_property_read_u32(dev, "adi,sdo-drive-strength",
149 &drive_strength);
150 if (err)
151 return err;
152
153 if (drive_strength > 3) {
154 dev_err_probe(dev, -EINVAL,
155 "adi,sdo-drive-strength must be less than 4\n");
156 return -EINVAL;
157 }
158
159 *val = drive_strength;
160
161 return 0;
162 }
163 EXPORT_SYMBOL_NS_GPL(ad3552r_get_drive_strength, "IIO_AD3552R");
164
ad3552r_get_custom_gain(struct device * dev,struct fwnode_handle * child,u8 * gs_p,u8 * gs_n,u16 * rfb,s16 * goffs)165 int ad3552r_get_custom_gain(struct device *dev, struct fwnode_handle *child,
166 u8 *gs_p, u8 *gs_n, u16 *rfb, s16 *goffs)
167 {
168 int err;
169 u32 val;
170 struct fwnode_handle *gain_child __free(fwnode_handle) =
171 fwnode_get_named_child_node(child,
172 "custom-output-range-config");
173
174 if (!gain_child)
175 return dev_err_probe(dev, -EINVAL,
176 "custom-output-range-config mandatory\n");
177
178 err = fwnode_property_read_u32(gain_child, "adi,gain-scaling-p", &val);
179 if (err)
180 return dev_err_probe(dev, err,
181 "adi,gain-scaling-p mandatory\n");
182 *gs_p = val;
183
184 err = fwnode_property_read_u32(gain_child, "adi,gain-scaling-n", &val);
185 if (err)
186 return dev_err_probe(dev, err,
187 "adi,gain-scaling-n property mandatory\n");
188 *gs_n = val;
189
190 err = fwnode_property_read_u32(gain_child, "adi,rfb-ohms", &val);
191 if (err)
192 return dev_err_probe(dev, err,
193 "adi,rfb-ohms mandatory\n");
194 *rfb = val;
195
196 err = fwnode_property_read_u32(gain_child, "adi,gain-offset", &val);
197 if (err)
198 return dev_err_probe(dev, err,
199 "adi,gain-offset mandatory\n");
200 *goffs = val;
201
202 return 0;
203 }
204 EXPORT_SYMBOL_NS_GPL(ad3552r_get_custom_gain, "IIO_AD3552R");
205
ad3552r_find_range(const struct ad3552r_model_data * model_info,s32 * vals)206 static int ad3552r_find_range(const struct ad3552r_model_data *model_info,
207 s32 *vals)
208 {
209 int i;
210
211 for (i = 0; i < model_info->num_ranges; i++)
212 if (vals[0] == model_info->ranges_table[i][0] * 1000 &&
213 vals[1] == model_info->ranges_table[i][1] * 1000)
214 return i;
215
216 return -EINVAL;
217 }
218
ad3552r_get_output_range(struct device * dev,const struct ad3552r_model_data * model_info,struct fwnode_handle * child,u32 * val)219 int ad3552r_get_output_range(struct device *dev,
220 const struct ad3552r_model_data *model_info,
221 struct fwnode_handle *child, u32 *val)
222 {
223 int ret;
224 s32 vals[2];
225
226 /* This property is optional, so returning -ENOENT if missing */
227 if (!fwnode_property_present(child, "adi,output-range-microvolt"))
228 return -ENOENT;
229
230 ret = fwnode_property_read_u32_array(child,
231 "adi,output-range-microvolt",
232 vals, 2);
233 if (ret)
234 return dev_err_probe(dev, ret,
235 "invalid adi,output-range-microvolt\n");
236
237 ret = ad3552r_find_range(model_info, vals);
238 if (ret < 0)
239 return dev_err_probe(dev, ret,
240 "invalid adi,output-range-microvolt value\n");
241
242 *val = ret;
243
244 return 0;
245 }
246 EXPORT_SYMBOL_NS_GPL(ad3552r_get_output_range, "IIO_AD3552R");
247
248 MODULE_DESCRIPTION("ad3552r common functions");
249 MODULE_LICENSE("GPL");
250