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1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* | |
3 | * ADC driver for the RICOH RN5T618 power management chip family | |
4 | * | |
5 | * Copyright (C) 2019 Andreas Kemnade | |
6 | */ | |
7 | ||
8 | #include <linux/kernel.h> | |
9 | #include <linux/device.h> | |
10 | #include <linux/errno.h> | |
11 | #include <linux/interrupt.h> | |
12 | #include <linux/init.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/mfd/rn5t618.h> | |
15 | #include <linux/platform_device.h> | |
16 | #include <linux/completion.h> | |
17 | #include <linux/regmap.h> | |
18 | #include <linux/iio/iio.h> | |
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19 | #include <linux/iio/driver.h> |
20 | #include <linux/iio/machine.h> | |
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21 | #include <linux/slab.h> |
22 | ||
23 | #define RN5T618_ADC_CONVERSION_TIMEOUT (msecs_to_jiffies(500)) | |
24 | #define RN5T618_REFERENCE_VOLT 2500 | |
25 | ||
26 | /* mask for selecting channels for single conversion */ | |
27 | #define RN5T618_ADCCNT3_CHANNEL_MASK 0x7 | |
28 | /* average 4-time conversion mode */ | |
29 | #define RN5T618_ADCCNT3_AVG BIT(3) | |
30 | /* set for starting a single conversion, gets cleared by hw when done */ | |
31 | #define RN5T618_ADCCNT3_GODONE BIT(4) | |
32 | /* automatic conversion, period is in ADCCNT2, selected channels are | |
33 | * in ADCCNT1 | |
34 | */ | |
35 | #define RN5T618_ADCCNT3_AUTO BIT(5) | |
36 | #define RN5T618_ADCEND_IRQ BIT(0) | |
37 | ||
38 | struct rn5t618_adc_data { | |
39 | struct device *dev; | |
40 | struct rn5t618 *rn5t618; | |
41 | struct completion conv_completion; | |
42 | int irq; | |
43 | }; | |
44 | ||
87a25333 AK |
45 | enum rn5t618_channels { |
46 | LIMMON = 0, | |
47 | VBAT, | |
48 | VADP, | |
49 | VUSB, | |
50 | VSYS, | |
51 | VTHM, | |
52 | AIN1, | |
53 | AIN0 | |
54 | }; | |
55 | ||
84cd574e | 56 | static const struct u16_fract rn5t618_ratios[8] = { |
87a25333 AK |
57 | [LIMMON] = {50, 32}, /* measured across 20mOhm, amplified by 32 */ |
58 | [VBAT] = {2, 1}, | |
59 | [VADP] = {3, 1}, | |
60 | [VUSB] = {3, 1}, | |
61 | [VSYS] = {3, 1}, | |
62 | [VTHM] = {1, 1}, | |
63 | [AIN1] = {1, 1}, | |
64 | [AIN0] = {1, 1}, | |
65 | }; | |
66 | ||
67 | static int rn5t618_read_adc_reg(struct rn5t618 *rn5t618, int reg, u16 *val) | |
68 | { | |
69 | u8 data[2]; | |
70 | int ret; | |
71 | ||
72 | ret = regmap_bulk_read(rn5t618->regmap, reg, data, sizeof(data)); | |
73 | if (ret < 0) | |
74 | return ret; | |
75 | ||
76 | *val = (data[0] << 4) | (data[1] & 0xF); | |
77 | ||
78 | return 0; | |
79 | } | |
80 | ||
81 | static irqreturn_t rn5t618_adc_irq(int irq, void *data) | |
82 | { | |
83 | struct rn5t618_adc_data *adc = data; | |
84 | unsigned int r = 0; | |
85 | int ret; | |
86 | ||
87 | /* clear low & high threshold irqs */ | |
88 | regmap_write(adc->rn5t618->regmap, RN5T618_IR_ADC1, 0); | |
89 | regmap_write(adc->rn5t618->regmap, RN5T618_IR_ADC2, 0); | |
90 | ||
91 | ret = regmap_read(adc->rn5t618->regmap, RN5T618_IR_ADC3, &r); | |
92 | if (ret < 0) | |
93 | dev_err(adc->dev, "failed to read IRQ status: %d\n", ret); | |
94 | ||
95 | regmap_write(adc->rn5t618->regmap, RN5T618_IR_ADC3, 0); | |
96 | ||
97 | if (r & RN5T618_ADCEND_IRQ) | |
98 | complete(&adc->conv_completion); | |
99 | ||
100 | return IRQ_HANDLED; | |
101 | } | |
102 | ||
103 | static int rn5t618_adc_read(struct iio_dev *iio_dev, | |
104 | const struct iio_chan_spec *chan, | |
105 | int *val, int *val2, long mask) | |
106 | { | |
107 | struct rn5t618_adc_data *adc = iio_priv(iio_dev); | |
108 | u16 raw; | |
109 | int ret; | |
110 | ||
111 | if (mask == IIO_CHAN_INFO_SCALE) { | |
112 | *val = RN5T618_REFERENCE_VOLT * | |
113 | rn5t618_ratios[chan->channel].numerator; | |
114 | *val2 = rn5t618_ratios[chan->channel].denominator * 4095; | |
115 | ||
116 | return IIO_VAL_FRACTIONAL; | |
117 | } | |
118 | ||
119 | /* select channel */ | |
120 | ret = regmap_update_bits(adc->rn5t618->regmap, RN5T618_ADCCNT3, | |
121 | RN5T618_ADCCNT3_CHANNEL_MASK, | |
122 | chan->channel); | |
123 | if (ret < 0) | |
124 | return ret; | |
125 | ||
126 | ret = regmap_write(adc->rn5t618->regmap, RN5T618_EN_ADCIR3, | |
127 | RN5T618_ADCEND_IRQ); | |
128 | if (ret < 0) | |
129 | return ret; | |
130 | ||
131 | ret = regmap_update_bits(adc->rn5t618->regmap, RN5T618_ADCCNT3, | |
132 | RN5T618_ADCCNT3_AVG, | |
133 | mask == IIO_CHAN_INFO_AVERAGE_RAW ? | |
134 | RN5T618_ADCCNT3_AVG : 0); | |
135 | if (ret < 0) | |
136 | return ret; | |
137 | ||
138 | init_completion(&adc->conv_completion); | |
139 | /* single conversion */ | |
140 | ret = regmap_update_bits(adc->rn5t618->regmap, RN5T618_ADCCNT3, | |
141 | RN5T618_ADCCNT3_GODONE, | |
142 | RN5T618_ADCCNT3_GODONE); | |
143 | if (ret < 0) | |
144 | return ret; | |
145 | ||
146 | ret = wait_for_completion_timeout(&adc->conv_completion, | |
147 | RN5T618_ADC_CONVERSION_TIMEOUT); | |
148 | if (ret == 0) { | |
149 | dev_warn(adc->dev, "timeout waiting for adc result\n"); | |
150 | return -ETIMEDOUT; | |
151 | } | |
152 | ||
153 | ret = rn5t618_read_adc_reg(adc->rn5t618, | |
154 | RN5T618_ILIMDATAH + 2 * chan->channel, | |
155 | &raw); | |
156 | if (ret < 0) | |
157 | return ret; | |
158 | ||
159 | *val = raw; | |
160 | ||
161 | return IIO_VAL_INT; | |
162 | } | |
163 | ||
164 | static const struct iio_info rn5t618_adc_iio_info = { | |
165 | .read_raw = &rn5t618_adc_read, | |
166 | }; | |
167 | ||
168 | #define RN5T618_ADC_CHANNEL(_channel, _type, _name) { \ | |
169 | .type = _type, \ | |
170 | .channel = _channel, \ | |
171 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ | |
172 | BIT(IIO_CHAN_INFO_AVERAGE_RAW) | \ | |
173 | BIT(IIO_CHAN_INFO_SCALE), \ | |
174 | .datasheet_name = _name, \ | |
175 | .indexed = 1. \ | |
176 | } | |
177 | ||
178 | static const struct iio_chan_spec rn5t618_adc_iio_channels[] = { | |
179 | RN5T618_ADC_CHANNEL(LIMMON, IIO_CURRENT, "LIMMON"), | |
180 | RN5T618_ADC_CHANNEL(VBAT, IIO_VOLTAGE, "VBAT"), | |
181 | RN5T618_ADC_CHANNEL(VADP, IIO_VOLTAGE, "VADP"), | |
182 | RN5T618_ADC_CHANNEL(VUSB, IIO_VOLTAGE, "VUSB"), | |
183 | RN5T618_ADC_CHANNEL(VSYS, IIO_VOLTAGE, "VSYS"), | |
184 | RN5T618_ADC_CHANNEL(VTHM, IIO_VOLTAGE, "VTHM"), | |
185 | RN5T618_ADC_CHANNEL(AIN1, IIO_VOLTAGE, "AIN1"), | |
186 | RN5T618_ADC_CHANNEL(AIN0, IIO_VOLTAGE, "AIN0") | |
187 | }; | |
188 | ||
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189 | static struct iio_map rn5t618_maps[] = { |
190 | IIO_MAP("VADP", "rn5t618-power", "vadp"), | |
191 | IIO_MAP("VUSB", "rn5t618-power", "vusb"), | |
192 | { /* sentinel */ } | |
193 | }; | |
194 | ||
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195 | static int rn5t618_adc_probe(struct platform_device *pdev) |
196 | { | |
197 | int ret; | |
198 | struct iio_dev *iio_dev; | |
199 | struct rn5t618_adc_data *adc; | |
200 | struct rn5t618 *rn5t618 = dev_get_drvdata(pdev->dev.parent); | |
201 | ||
202 | iio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc)); | |
203 | if (!iio_dev) { | |
204 | dev_err(&pdev->dev, "failed allocating iio device\n"); | |
205 | return -ENOMEM; | |
206 | } | |
207 | ||
208 | adc = iio_priv(iio_dev); | |
209 | adc->dev = &pdev->dev; | |
210 | adc->rn5t618 = rn5t618; | |
211 | ||
212 | if (rn5t618->irq_data) | |
213 | adc->irq = regmap_irq_get_virq(rn5t618->irq_data, | |
214 | RN5T618_IRQ_ADC); | |
215 | ||
216 | if (adc->irq <= 0) { | |
217 | dev_err(&pdev->dev, "get virq failed\n"); | |
218 | return -EINVAL; | |
219 | } | |
220 | ||
221 | init_completion(&adc->conv_completion); | |
222 | ||
223 | iio_dev->name = dev_name(&pdev->dev); | |
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224 | iio_dev->info = &rn5t618_adc_iio_info; |
225 | iio_dev->modes = INDIO_DIRECT_MODE; | |
226 | iio_dev->channels = rn5t618_adc_iio_channels; | |
227 | iio_dev->num_channels = ARRAY_SIZE(rn5t618_adc_iio_channels); | |
228 | ||
229 | /* stop any auto-conversion */ | |
230 | ret = regmap_write(rn5t618->regmap, RN5T618_ADCCNT3, 0); | |
231 | if (ret < 0) | |
232 | return ret; | |
233 | ||
234 | platform_set_drvdata(pdev, iio_dev); | |
235 | ||
236 | ret = devm_request_threaded_irq(adc->dev, adc->irq, NULL, | |
237 | rn5t618_adc_irq, | |
238 | IRQF_ONESHOT, dev_name(adc->dev), | |
239 | adc); | |
240 | if (ret < 0) { | |
241 | dev_err(adc->dev, "request irq %d failed: %d\n", adc->irq, ret); | |
242 | return ret; | |
243 | } | |
244 | ||
bdf48481 | 245 | ret = devm_iio_map_array_register(adc->dev, iio_dev, rn5t618_maps); |
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246 | if (ret < 0) |
247 | return ret; | |
248 | ||
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249 | return devm_iio_device_register(adc->dev, iio_dev); |
250 | } | |
251 | ||
252 | static struct platform_driver rn5t618_adc_driver = { | |
253 | .driver = { | |
254 | .name = "rn5t618-adc", | |
255 | }, | |
256 | .probe = rn5t618_adc_probe, | |
257 | }; | |
258 | ||
259 | module_platform_driver(rn5t618_adc_driver); | |
260 | MODULE_ALIAS("platform:rn5t618-adc"); | |
261 | MODULE_DESCRIPTION("RICOH RN5T618 ADC driver"); | |
262 | MODULE_LICENSE("GPL"); |