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> |
19 | #include <linux/iio/driver.h> |
20 | #include <linux/iio/machine.h> |
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 | |
45 | enum rn5t618_channels { |
46 | LIMMON = 0, |
47 | VBAT, |
48 | VADP, |
49 | VUSB, |
50 | VSYS, |
51 | VTHM, |
52 | AIN1, |
53 | AIN0 |
54 | }; |
55 | |
56 | static const struct u16_fract rn5t618_ratios[8] = { |
57 | [LIMMON] = {50, 32}, /* measured across 20mOhm, amplified by 32 */ |
58 | [VBAT] = {.numerator: 2, .denominator: 1}, |
59 | [VADP] = {.numerator: 3, .denominator: 1}, |
60 | [VUSB] = {.numerator: 3, .denominator: 1}, |
61 | [VSYS] = {.numerator: 3, .denominator: 1}, |
62 | [VTHM] = {.numerator: 1, .denominator: 1}, |
63 | [AIN1] = {.numerator: 1, .denominator: 1}, |
64 | [AIN0] = {.numerator: 1, .denominator: 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(map: rn5t618->regmap, reg, val: data, val_count: 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(map: adc->rn5t618->regmap, RN5T618_IR_ADC1, val: 0); |
89 | regmap_write(map: adc->rn5t618->regmap, RN5T618_IR_ADC2, val: 0); |
90 | |
91 | ret = regmap_read(map: adc->rn5t618->regmap, RN5T618_IR_ADC3, val: &r); |
92 | if (ret < 0) |
93 | dev_err(adc->dev, "failed to read IRQ status: %d\n" , ret); |
94 | |
95 | regmap_write(map: adc->rn5t618->regmap, RN5T618_IR_ADC3, val: 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(indio_dev: 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(map: adc->rn5t618->regmap, RN5T618_ADCCNT3, |
121 | RN5T618_ADCCNT3_CHANNEL_MASK, |
122 | val: chan->channel); |
123 | if (ret < 0) |
124 | return ret; |
125 | |
126 | ret = regmap_write(map: adc->rn5t618->regmap, RN5T618_EN_ADCIR3, |
127 | RN5T618_ADCEND_IRQ); |
128 | if (ret < 0) |
129 | return ret; |
130 | |
131 | ret = regmap_update_bits(map: adc->rn5t618->regmap, RN5T618_ADCCNT3, |
132 | RN5T618_ADCCNT3_AVG, |
133 | val: mask == IIO_CHAN_INFO_AVERAGE_RAW ? |
134 | RN5T618_ADCCNT3_AVG : 0); |
135 | if (ret < 0) |
136 | return ret; |
137 | |
138 | init_completion(x: &adc->conv_completion); |
139 | /* single conversion */ |
140 | ret = regmap_update_bits(map: 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(x: &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(rn5t618: adc->rn5t618, |
154 | RN5T618_ILIMDATAH + 2 * chan->channel, |
155 | val: &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 | |
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 | |
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(dev: pdev->dev.parent); |
201 | |
202 | iio_dev = devm_iio_device_alloc(parent: &pdev->dev, sizeof_priv: 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(indio_dev: iio_dev); |
209 | adc->dev = &pdev->dev; |
210 | adc->rn5t618 = rn5t618; |
211 | |
212 | if (rn5t618->irq_data) |
213 | adc->irq = regmap_irq_get_virq(data: rn5t618->irq_data, |
214 | irq: 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(x: &adc->conv_completion); |
222 | |
223 | iio_dev->name = dev_name(dev: &pdev->dev); |
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(map: rn5t618->regmap, RN5T618_ADCCNT3, val: 0); |
231 | if (ret < 0) |
232 | return ret; |
233 | |
234 | platform_set_drvdata(pdev, data: iio_dev); |
235 | |
236 | ret = devm_request_threaded_irq(dev: adc->dev, irq: adc->irq, NULL, |
237 | thread_fn: rn5t618_adc_irq, |
238 | IRQF_ONESHOT, devname: dev_name(dev: adc->dev), |
239 | dev_id: adc); |
240 | if (ret < 0) { |
241 | dev_err(adc->dev, "request irq %d failed: %d\n" , adc->irq, ret); |
242 | return ret; |
243 | } |
244 | |
245 | ret = devm_iio_map_array_register(dev: adc->dev, indio_dev: iio_dev, maps: rn5t618_maps); |
246 | if (ret < 0) |
247 | return ret; |
248 | |
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" ); |
263 | |