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__5V] = { 0, 5000 },
26 [AD3542R_CH_OUTPUT_RANGE_0__10V] = { 0, 10000 },
27 [AD3542R_CH_OUTPUT_RANGE_NEG_5__5V] = { -5000, 5000 },
28 [AD3542R_CH_OUTPUT_RANGE_NEG_2P5__7P5V] = { -2500, 7500 }
29 };
30 EXPORT_SYMBOL_NS_GPL(ad3542r_ch_ranges, "IIO_AD3552R");
31
32 /* Gain * AD3552R_GAIN_SCALE */
33 static const s32 gains_scaling_table[] = {
34 [AD3552R_CH_GAIN_SCALING_1] = 1000,
35 [AD3552R_CH_GAIN_SCALING_0_5] = 500,
36 [AD3552R_CH_GAIN_SCALING_0_25] = 250,
37 [AD3552R_CH_GAIN_SCALING_0_125] = 125
38 };
39
ad3552r_calc_custom_gain(u8 p,u8 n,s16 goffs)40 u16 ad3552r_calc_custom_gain(u8 p, u8 n, s16 goffs)
41 {
42 return FIELD_PREP(AD3552R_MASK_CH_RANGE_OVERRIDE, 1) |
43 FIELD_PREP(AD3552R_MASK_CH_GAIN_SCALING_P, p) |
44 FIELD_PREP(AD3552R_MASK_CH_GAIN_SCALING_N, n) |
45 FIELD_PREP(AD3552R_MASK_CH_OFFSET_BIT_8, abs(goffs)) |
46 FIELD_PREP(AD3552R_MASK_CH_OFFSET_POLARITY, goffs < 0);
47 }
48 EXPORT_SYMBOL_NS_GPL(ad3552r_calc_custom_gain, "IIO_AD3552R");
49
ad3552r_get_custom_range(struct ad3552r_ch_data * ch_data,s32 * v_min,s32 * v_max)50 static void ad3552r_get_custom_range(struct ad3552r_ch_data *ch_data,
51 s32 *v_min, s32 *v_max)
52 {
53 s64 vref, tmp, common, offset, gn, gp;
54 /*
55 * From datasheet formula (In Volts):
56 * Vmin = 2.5 + [(GainN + Offset / 1024) * 2.5 * Rfb * 1.03]
57 * Vmax = 2.5 - [(GainP + Offset / 1024) * 2.5 * Rfb * 1.03]
58 * Calculus are converted to milivolts
59 */
60 vref = 2500;
61 /* 2.5 * 1.03 * 1000 (To mV) */
62 common = 2575 * ch_data->rfb;
63 offset = ch_data->gain_offset;
64
65 gn = gains_scaling_table[ch_data->n];
66 tmp = (1024 * gn + AD3552R_GAIN_SCALE * offset) * common;
67 tmp = div_s64(tmp, 1024 * AD3552R_GAIN_SCALE);
68 *v_max = vref + tmp;
69
70 gp = gains_scaling_table[ch_data->p];
71 tmp = (1024 * gp - AD3552R_GAIN_SCALE * offset) * common;
72 tmp = div_s64(tmp, 1024 * AD3552R_GAIN_SCALE);
73 *v_min = vref - tmp;
74 }
75
ad3552r_calc_gain_and_offset(struct ad3552r_ch_data * ch_data,const struct ad3552r_model_data * model_data)76 void ad3552r_calc_gain_and_offset(struct ad3552r_ch_data *ch_data,
77 const struct ad3552r_model_data *model_data)
78 {
79 s32 idx, v_max, v_min, span, rem;
80 s64 tmp;
81
82 if (ch_data->range_override) {
83 ad3552r_get_custom_range(ch_data, &v_min, &v_max);
84 } else {
85 /* Normal range */
86 idx = ch_data->range;
87 v_min = model_data->ranges_table[idx][0];
88 v_max = model_data->ranges_table[idx][1];
89 }
90
91 /*
92 * From datasheet formula:
93 * Vout = Span * (D / 65536) + Vmin
94 * Converted to scale and offset:
95 * Scale = Span / 65536
96 * Offset = 65536 * Vmin / Span
97 *
98 * Reminders are in micros in order to be printed as
99 * IIO_VAL_INT_PLUS_MICRO
100 */
101 span = v_max - v_min;
102 ch_data->scale_int = div_s64_rem(span, 65536, &rem);
103 /* Do operations in microvolts */
104 ch_data->scale_dec = DIV_ROUND_CLOSEST((s64)rem * 1000000, 65536);
105
106 ch_data->offset_int = div_s64_rem(v_min * 65536, span, &rem);
107 tmp = (s64)rem * 1000000;
108 ch_data->offset_dec = div_s64(tmp, span);
109 }
110 EXPORT_SYMBOL_NS_GPL(ad3552r_calc_gain_and_offset, "IIO_AD3552R");
111
ad3552r_get_ref_voltage(struct device * dev,u32 * val)112 int ad3552r_get_ref_voltage(struct device *dev, u32 *val)
113 {
114 int voltage;
115 int delta = 100000;
116
117 voltage = devm_regulator_get_enable_read_voltage(dev, "vref");
118 if (voltage < 0 && voltage != -ENODEV)
119 return dev_err_probe(dev, voltage,
120 "Error getting vref voltage\n");
121
122 if (voltage == -ENODEV) {
123 if (device_property_read_bool(dev, "adi,vref-out-en"))
124 *val = AD3552R_INTERNAL_VREF_PIN_2P5V;
125 else
126 *val = AD3552R_INTERNAL_VREF_PIN_FLOATING;
127
128 return 0;
129 }
130
131 if (voltage > 2500000 + delta || voltage < 2500000 - delta) {
132 dev_warn(dev, "vref-supply must be 2.5V");
133 return -EINVAL;
134 }
135
136 *val = AD3552R_EXTERNAL_VREF_PIN_INPUT;
137
138 return 0;
139 }
140 EXPORT_SYMBOL_NS_GPL(ad3552r_get_ref_voltage, "IIO_AD3552R");
141
ad3552r_get_drive_strength(struct device * dev,u32 * val)142 int ad3552r_get_drive_strength(struct device *dev, u32 *val)
143 {
144 int err;
145 u32 drive_strength;
146
147 err = device_property_read_u32(dev, "adi,sdo-drive-strength",
148 &drive_strength);
149 if (err)
150 return err;
151
152 if (drive_strength > 3) {
153 dev_err_probe(dev, -EINVAL,
154 "adi,sdo-drive-strength must be less than 4\n");
155 return -EINVAL;
156 }
157
158 *val = drive_strength;
159
160 return 0;
161 }
162 EXPORT_SYMBOL_NS_GPL(ad3552r_get_drive_strength, "IIO_AD3552R");
163
ad3552r_get_custom_gain(struct device * dev,struct fwnode_handle * child,u8 * gs_p,u8 * gs_n,u16 * rfb,s16 * goffs)164 int ad3552r_get_custom_gain(struct device *dev, struct fwnode_handle *child,
165 u8 *gs_p, u8 *gs_n, u16 *rfb, s16 *goffs)
166 {
167 int err;
168 u32 val;
169 struct fwnode_handle *gain_child __free(fwnode_handle) =
170 fwnode_get_named_child_node(child,
171 "custom-output-range-config");
172
173 if (!gain_child)
174 return dev_err_probe(dev, -EINVAL,
175 "custom-output-range-config mandatory\n");
176
177 err = fwnode_property_read_u32(gain_child, "adi,gain-scaling-p", &val);
178 if (err)
179 return dev_err_probe(dev, err,
180 "adi,gain-scaling-p mandatory\n");
181 *gs_p = val;
182
183 err = fwnode_property_read_u32(gain_child, "adi,gain-scaling-n", &val);
184 if (err)
185 return dev_err_probe(dev, err,
186 "adi,gain-scaling-n property mandatory\n");
187 *gs_n = val;
188
189 err = fwnode_property_read_u32(gain_child, "adi,rfb-ohms", &val);
190 if (err)
191 return dev_err_probe(dev, err,
192 "adi,rfb-ohms mandatory\n");
193 *rfb = val;
194
195 err = fwnode_property_read_u32(gain_child, "adi,gain-offset", &val);
196 if (err)
197 return dev_err_probe(dev, err,
198 "adi,gain-offset mandatory\n");
199 *goffs = val;
200
201 return 0;
202 }
203 EXPORT_SYMBOL_NS_GPL(ad3552r_get_custom_gain, "IIO_AD3552R");
204
ad3552r_find_range(const struct ad3552r_model_data * model_info,s32 * vals)205 static int ad3552r_find_range(const struct ad3552r_model_data *model_info,
206 s32 *vals)
207 {
208 int i;
209
210 for (i = 0; i < model_info->num_ranges; i++)
211 if (vals[0] == model_info->ranges_table[i][0] * 1000 &&
212 vals[1] == model_info->ranges_table[i][1] * 1000)
213 return i;
214
215 return -EINVAL;
216 }
217
ad3552r_get_output_range(struct device * dev,const struct ad3552r_model_data * model_info,struct fwnode_handle * child,u32 * val)218 int ad3552r_get_output_range(struct device *dev,
219 const struct ad3552r_model_data *model_info,
220 struct fwnode_handle *child, u32 *val)
221 {
222 int ret;
223 s32 vals[2];
224
225 /* This property is optional, so returning -ENOENT if missing */
226 if (!fwnode_property_present(child, "adi,output-range-microvolt"))
227 return -ENOENT;
228
229 ret = fwnode_property_read_u32_array(child,
230 "adi,output-range-microvolt",
231 vals, 2);
232 if (ret)
233 return dev_err_probe(dev, ret,
234 "invalid adi,output-range-microvolt\n");
235
236 ret = ad3552r_find_range(model_info, vals);
237 if (ret < 0)
238 return dev_err_probe(dev, ret,
239 "invalid adi,output-range-microvolt value\n");
240
241 *val = ret;
242
243 return 0;
244 }
245 EXPORT_SYMBOL_NS_GPL(ad3552r_get_output_range, "IIO_AD3552R");
246
247 MODULE_DESCRIPTION("ad3552r common functions");
248 MODULE_LICENSE("GPL");
249