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Heiko Stübner44d6f2e2014-07-23 22:24:00 +01001/*
2 * Rockchip Successive Approximation Register (SAR) A/D Converter
3 * Copyright (C) 2014 ROCKCHIP, Inc.
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 */
15
16#include <linux/module.h>
17#include <linux/platform_device.h>
18#include <linux/interrupt.h>
19#include <linux/io.h>
20#include <linux/of.h>
Heiko Stübner4c21bbb2014-09-15 22:47:00 +010021#include <linux/of_device.h>
Heiko Stübner44d6f2e2014-07-23 22:24:00 +010022#include <linux/clk.h>
23#include <linux/completion.h>
24#include <linux/regulator/consumer.h>
25#include <linux/iio/iio.h>
26
27#define SARADC_DATA 0x00
Heiko Stübner44d6f2e2014-07-23 22:24:00 +010028
29#define SARADC_STAS 0x04
30#define SARADC_STAS_BUSY BIT(0)
31
32#define SARADC_CTRL 0x08
33#define SARADC_CTRL_IRQ_STATUS BIT(6)
34#define SARADC_CTRL_IRQ_ENABLE BIT(5)
35#define SARADC_CTRL_POWER_CTRL BIT(3)
36#define SARADC_CTRL_CHN_MASK 0x7
37
38#define SARADC_DLY_PU_SOC 0x0c
39#define SARADC_DLY_PU_SOC_MASK 0x3f
40
Heiko Stübner44d6f2e2014-07-23 22:24:00 +010041#define SARADC_TIMEOUT msecs_to_jiffies(100)
42
Heiko Stübner4c21bbb2014-09-15 22:47:00 +010043struct rockchip_saradc_data {
44 int num_bits;
45 const struct iio_chan_spec *channels;
46 int num_channels;
47 unsigned long clk_rate;
48};
49
Heiko Stübner44d6f2e2014-07-23 22:24:00 +010050struct rockchip_saradc {
51 void __iomem *regs;
52 struct clk *pclk;
53 struct clk *clk;
54 struct completion completion;
55 struct regulator *vref;
Heiko Stübner4c21bbb2014-09-15 22:47:00 +010056 const struct rockchip_saradc_data *data;
Heiko Stübner44d6f2e2014-07-23 22:24:00 +010057 u16 last_val;
58};
59
60static int rockchip_saradc_read_raw(struct iio_dev *indio_dev,
61 struct iio_chan_spec const *chan,
62 int *val, int *val2, long mask)
63{
64 struct rockchip_saradc *info = iio_priv(indio_dev);
65 int ret;
66
67 switch (mask) {
68 case IIO_CHAN_INFO_RAW:
69 mutex_lock(&indio_dev->mlock);
70
71 reinit_completion(&info->completion);
72
73 /* 8 clock periods as delay between power up and start cmd */
74 writel_relaxed(8, info->regs + SARADC_DLY_PU_SOC);
75
76 /* Select the channel to be used and trigger conversion */
77 writel(SARADC_CTRL_POWER_CTRL
78 | (chan->channel & SARADC_CTRL_CHN_MASK)
79 | SARADC_CTRL_IRQ_ENABLE,
80 info->regs + SARADC_CTRL);
81
82 if (!wait_for_completion_timeout(&info->completion,
83 SARADC_TIMEOUT)) {
84 writel_relaxed(0, info->regs + SARADC_CTRL);
85 mutex_unlock(&indio_dev->mlock);
86 return -ETIMEDOUT;
87 }
88
89 *val = info->last_val;
90 mutex_unlock(&indio_dev->mlock);
91 return IIO_VAL_INT;
92 case IIO_CHAN_INFO_SCALE:
93 ret = regulator_get_voltage(info->vref);
94 if (ret < 0) {
95 dev_err(&indio_dev->dev, "failed to get voltage\n");
96 return ret;
97 }
98
99 *val = ret / 1000;
Heiko Stübner4c21bbb2014-09-15 22:47:00 +0100100 *val2 = info->data->num_bits;
Heiko Stübner44d6f2e2014-07-23 22:24:00 +0100101 return IIO_VAL_FRACTIONAL_LOG2;
102 default:
103 return -EINVAL;
104 }
105}
106
107static irqreturn_t rockchip_saradc_isr(int irq, void *dev_id)
108{
109 struct rockchip_saradc *info = (struct rockchip_saradc *)dev_id;
110
111 /* Read value */
112 info->last_val = readl_relaxed(info->regs + SARADC_DATA);
Heiko Stübner4c21bbb2014-09-15 22:47:00 +0100113 info->last_val &= GENMASK(info->data->num_bits - 1, 0);
Heiko Stübner44d6f2e2014-07-23 22:24:00 +0100114
115 /* Clear irq & power down adc */
116 writel_relaxed(0, info->regs + SARADC_CTRL);
117
118 complete(&info->completion);
119
120 return IRQ_HANDLED;
121}
122
123static const struct iio_info rockchip_saradc_iio_info = {
124 .read_raw = rockchip_saradc_read_raw,
125 .driver_module = THIS_MODULE,
126};
127
128#define ADC_CHANNEL(_index, _id) { \
129 .type = IIO_VOLTAGE, \
130 .indexed = 1, \
131 .channel = _index, \
132 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
133 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
134 .datasheet_name = _id, \
135}
136
137static const struct iio_chan_spec rockchip_saradc_iio_channels[] = {
138 ADC_CHANNEL(0, "adc0"),
139 ADC_CHANNEL(1, "adc1"),
140 ADC_CHANNEL(2, "adc2"),
141};
142
Heiko Stübner4c21bbb2014-09-15 22:47:00 +0100143static const struct rockchip_saradc_data saradc_data = {
144 .num_bits = 10,
145 .channels = rockchip_saradc_iio_channels,
146 .num_channels = ARRAY_SIZE(rockchip_saradc_iio_channels),
147 .clk_rate = 1000000,
148};
149
150static const struct iio_chan_spec rockchip_rk3066_tsadc_iio_channels[] = {
151 ADC_CHANNEL(0, "adc0"),
152 ADC_CHANNEL(1, "adc1"),
153};
154
155static const struct rockchip_saradc_data rk3066_tsadc_data = {
156 .num_bits = 12,
157 .channels = rockchip_rk3066_tsadc_iio_channels,
158 .num_channels = ARRAY_SIZE(rockchip_rk3066_tsadc_iio_channels),
159 .clk_rate = 50000,
160};
161
162static const struct of_device_id rockchip_saradc_match[] = {
163 {
164 .compatible = "rockchip,saradc",
165 .data = &saradc_data,
166 }, {
167 .compatible = "rockchip,rk3066-tsadc",
168 .data = &rk3066_tsadc_data,
169 },
170 {},
171};
172MODULE_DEVICE_TABLE(of, rockchip_saradc_match);
173
Heiko Stübner44d6f2e2014-07-23 22:24:00 +0100174static int rockchip_saradc_probe(struct platform_device *pdev)
175{
176 struct rockchip_saradc *info = NULL;
177 struct device_node *np = pdev->dev.of_node;
178 struct iio_dev *indio_dev = NULL;
179 struct resource *mem;
Heiko Stübner4c21bbb2014-09-15 22:47:00 +0100180 const struct of_device_id *match;
Heiko Stübner44d6f2e2014-07-23 22:24:00 +0100181 int ret;
182 int irq;
Heiko Stübner44d6f2e2014-07-23 22:24:00 +0100183
184 if (!np)
185 return -ENODEV;
186
187 indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info));
188 if (!indio_dev) {
189 dev_err(&pdev->dev, "failed allocating iio device\n");
190 return -ENOMEM;
191 }
192 info = iio_priv(indio_dev);
193
Heiko Stübner4c21bbb2014-09-15 22:47:00 +0100194 match = of_match_device(rockchip_saradc_match, &pdev->dev);
195 info->data = match->data;
196
Heiko Stübner44d6f2e2014-07-23 22:24:00 +0100197 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
198 info->regs = devm_ioremap_resource(&pdev->dev, mem);
199 if (IS_ERR(info->regs))
200 return PTR_ERR(info->regs);
201
202 init_completion(&info->completion);
203
204 irq = platform_get_irq(pdev, 0);
205 if (irq < 0) {
206 dev_err(&pdev->dev, "no irq resource?\n");
207 return irq;
208 }
209
210 ret = devm_request_irq(&pdev->dev, irq, rockchip_saradc_isr,
211 0, dev_name(&pdev->dev), info);
212 if (ret < 0) {
213 dev_err(&pdev->dev, "failed requesting irq %d\n", irq);
214 return ret;
215 }
216
217 info->pclk = devm_clk_get(&pdev->dev, "apb_pclk");
218 if (IS_ERR(info->pclk)) {
219 dev_err(&pdev->dev, "failed to get pclk\n");
220 return PTR_ERR(info->pclk);
221 }
222
223 info->clk = devm_clk_get(&pdev->dev, "saradc");
224 if (IS_ERR(info->clk)) {
225 dev_err(&pdev->dev, "failed to get adc clock\n");
226 return PTR_ERR(info->clk);
227 }
228
229 info->vref = devm_regulator_get(&pdev->dev, "vref");
230 if (IS_ERR(info->vref)) {
231 dev_err(&pdev->dev, "failed to get regulator, %ld\n",
232 PTR_ERR(info->vref));
233 return PTR_ERR(info->vref);
234 }
235
236 /*
Heiko Stübner4c21bbb2014-09-15 22:47:00 +0100237 * Use a default value for the converter clock.
Heiko Stübner44d6f2e2014-07-23 22:24:00 +0100238 * This may become user-configurable in the future.
239 */
Heiko Stübner4c21bbb2014-09-15 22:47:00 +0100240 ret = clk_set_rate(info->clk, info->data->clk_rate);
Heiko Stübner44d6f2e2014-07-23 22:24:00 +0100241 if (ret < 0) {
242 dev_err(&pdev->dev, "failed to set adc clk rate, %d\n", ret);
243 return ret;
244 }
245
246 ret = regulator_enable(info->vref);
247 if (ret < 0) {
248 dev_err(&pdev->dev, "failed to enable vref regulator\n");
249 return ret;
250 }
251
252 ret = clk_prepare_enable(info->pclk);
253 if (ret < 0) {
254 dev_err(&pdev->dev, "failed to enable pclk\n");
255 goto err_reg_voltage;
256 }
257
258 ret = clk_prepare_enable(info->clk);
259 if (ret < 0) {
260 dev_err(&pdev->dev, "failed to enable converter clock\n");
261 goto err_pclk;
262 }
263
264 platform_set_drvdata(pdev, indio_dev);
265
266 indio_dev->name = dev_name(&pdev->dev);
267 indio_dev->dev.parent = &pdev->dev;
268 indio_dev->dev.of_node = pdev->dev.of_node;
269 indio_dev->info = &rockchip_saradc_iio_info;
270 indio_dev->modes = INDIO_DIRECT_MODE;
271
Heiko Stübner4c21bbb2014-09-15 22:47:00 +0100272 indio_dev->channels = info->data->channels;
273 indio_dev->num_channels = info->data->num_channels;
Heiko Stübner44d6f2e2014-07-23 22:24:00 +0100274
275 ret = iio_device_register(indio_dev);
276 if (ret)
277 goto err_clk;
278
279 return 0;
280
281err_clk:
282 clk_disable_unprepare(info->clk);
283err_pclk:
284 clk_disable_unprepare(info->pclk);
285err_reg_voltage:
286 regulator_disable(info->vref);
287 return ret;
288}
289
290static int rockchip_saradc_remove(struct platform_device *pdev)
291{
292 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
293 struct rockchip_saradc *info = iio_priv(indio_dev);
294
295 iio_device_unregister(indio_dev);
296 clk_disable_unprepare(info->clk);
297 clk_disable_unprepare(info->pclk);
298 regulator_disable(info->vref);
299
300 return 0;
301}
302
303#ifdef CONFIG_PM_SLEEP
304static int rockchip_saradc_suspend(struct device *dev)
305{
306 struct iio_dev *indio_dev = dev_get_drvdata(dev);
307 struct rockchip_saradc *info = iio_priv(indio_dev);
308
309 clk_disable_unprepare(info->clk);
310 clk_disable_unprepare(info->pclk);
311 regulator_disable(info->vref);
312
313 return 0;
314}
315
316static int rockchip_saradc_resume(struct device *dev)
317{
318 struct iio_dev *indio_dev = dev_get_drvdata(dev);
319 struct rockchip_saradc *info = iio_priv(indio_dev);
320 int ret;
321
322 ret = regulator_enable(info->vref);
323 if (ret)
324 return ret;
325
326 ret = clk_prepare_enable(info->pclk);
327 if (ret)
328 return ret;
329
330 ret = clk_prepare_enable(info->clk);
331 if (ret)
332 return ret;
333
334 return ret;
335}
336#endif
337
338static SIMPLE_DEV_PM_OPS(rockchip_saradc_pm_ops,
339 rockchip_saradc_suspend, rockchip_saradc_resume);
340
Heiko Stübner44d6f2e2014-07-23 22:24:00 +0100341static struct platform_driver rockchip_saradc_driver = {
342 .probe = rockchip_saradc_probe,
343 .remove = rockchip_saradc_remove,
344 .driver = {
345 .name = "rockchip-saradc",
Heiko Stübner44d6f2e2014-07-23 22:24:00 +0100346 .of_match_table = rockchip_saradc_match,
347 .pm = &rockchip_saradc_pm_ops,
348 },
349};
350
351module_platform_driver(rockchip_saradc_driver);
Heiko Stuebnerdc7b8d92015-05-25 22:36:58 +0200352
353MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
354MODULE_DESCRIPTION("Rockchip SARADC driver");
355MODULE_LICENSE("GPL v2");