2 * Rockchip Successive Approximation Register (SAR) A/D Converter
3 * Copyright (C) 2014 ROCKCHIP, Inc.
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.
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.
16 #include <linux/module.h>
17 #include <linux/platform_device.h>
18 #include <linux/interrupt.h>
21 #include <linux/of_device.h>
22 #include <linux/clk.h>
23 #include <linux/completion.h>
24 #include <linux/delay.h>
25 #include <linux/reset.h>
26 #include <linux/regulator/consumer.h>
27 #include <linux/iio/iio.h>
29 #define SARADC_DATA 0x00
31 #define SARADC_STAS 0x04
32 #define SARADC_STAS_BUSY BIT(0)
34 #define SARADC_CTRL 0x08
35 #define SARADC_CTRL_IRQ_STATUS BIT(6)
36 #define SARADC_CTRL_IRQ_ENABLE BIT(5)
37 #define SARADC_CTRL_POWER_CTRL BIT(3)
38 #define SARADC_CTRL_CHN_MASK 0x7
40 #define SARADC_DLY_PU_SOC 0x0c
41 #define SARADC_DLY_PU_SOC_MASK 0x3f
43 #define SARADC_TIMEOUT msecs_to_jiffies(100)
45 struct rockchip_saradc_data {
47 const struct iio_chan_spec *channels;
49 unsigned long clk_rate;
52 struct rockchip_saradc {
56 struct completion completion;
57 struct regulator *vref;
58 struct reset_control *reset;
59 const struct rockchip_saradc_data *data;
63 static int rockchip_saradc_read_raw(struct iio_dev *indio_dev,
64 struct iio_chan_spec const *chan,
65 int *val, int *val2, long mask)
67 struct rockchip_saradc *info = iio_priv(indio_dev);
71 case IIO_CHAN_INFO_RAW:
72 mutex_lock(&indio_dev->mlock);
74 reinit_completion(&info->completion);
76 /* 8 clock periods as delay between power up and start cmd */
77 writel_relaxed(8, info->regs + SARADC_DLY_PU_SOC);
79 /* Select the channel to be used and trigger conversion */
80 writel(SARADC_CTRL_POWER_CTRL
81 | (chan->channel & SARADC_CTRL_CHN_MASK)
82 | SARADC_CTRL_IRQ_ENABLE,
83 info->regs + SARADC_CTRL);
85 if (!wait_for_completion_timeout(&info->completion,
87 writel_relaxed(0, info->regs + SARADC_CTRL);
88 mutex_unlock(&indio_dev->mlock);
92 *val = info->last_val;
93 mutex_unlock(&indio_dev->mlock);
95 case IIO_CHAN_INFO_SCALE:
96 ret = regulator_get_voltage(info->vref);
98 dev_err(&indio_dev->dev, "failed to get voltage\n");
103 *val2 = info->data->num_bits;
104 return IIO_VAL_FRACTIONAL_LOG2;
110 static irqreturn_t rockchip_saradc_isr(int irq, void *dev_id)
112 struct rockchip_saradc *info = (struct rockchip_saradc *)dev_id;
115 info->last_val = readl_relaxed(info->regs + SARADC_DATA);
116 info->last_val &= GENMASK(info->data->num_bits - 1, 0);
118 /* Clear irq & power down adc */
119 writel_relaxed(0, info->regs + SARADC_CTRL);
121 complete(&info->completion);
126 static const struct iio_info rockchip_saradc_iio_info = {
127 .read_raw = rockchip_saradc_read_raw,
128 .driver_module = THIS_MODULE,
131 #define ADC_CHANNEL(_index, _id) { \
132 .type = IIO_VOLTAGE, \
135 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
136 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
137 .datasheet_name = _id, \
140 static const struct iio_chan_spec rockchip_saradc_iio_channels[] = {
141 ADC_CHANNEL(0, "adc0"),
142 ADC_CHANNEL(1, "adc1"),
143 ADC_CHANNEL(2, "adc2"),
146 static const struct rockchip_saradc_data saradc_data = {
148 .channels = rockchip_saradc_iio_channels,
149 .num_channels = ARRAY_SIZE(rockchip_saradc_iio_channels),
153 static const struct iio_chan_spec rockchip_rk3066_tsadc_iio_channels[] = {
154 ADC_CHANNEL(0, "adc0"),
155 ADC_CHANNEL(1, "adc1"),
158 static const struct rockchip_saradc_data rk3066_tsadc_data = {
160 .channels = rockchip_rk3066_tsadc_iio_channels,
161 .num_channels = ARRAY_SIZE(rockchip_rk3066_tsadc_iio_channels),
165 static const struct of_device_id rockchip_saradc_match[] = {
167 .compatible = "rockchip,saradc",
168 .data = &saradc_data,
170 .compatible = "rockchip,rk3066-tsadc",
171 .data = &rk3066_tsadc_data,
175 MODULE_DEVICE_TABLE(of, rockchip_saradc_match);
178 * Reset SARADC Controller.
180 static void rockchip_saradc_reset_controller(struct reset_control *reset)
182 reset_control_assert(reset);
183 usleep_range(10, 20);
184 reset_control_deassert(reset);
187 static int rockchip_saradc_probe(struct platform_device *pdev)
189 struct rockchip_saradc *info = NULL;
190 struct device_node *np = pdev->dev.of_node;
191 struct iio_dev *indio_dev = NULL;
192 struct resource *mem;
193 const struct of_device_id *match;
200 indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info));
202 dev_err(&pdev->dev, "failed allocating iio device\n");
205 info = iio_priv(indio_dev);
207 match = of_match_device(rockchip_saradc_match, &pdev->dev);
208 info->data = match->data;
210 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
211 info->regs = devm_ioremap_resource(&pdev->dev, mem);
212 if (IS_ERR(info->regs))
213 return PTR_ERR(info->regs);
216 * The reset should be an optional property, as it should work
217 * with old devicetrees as well
219 info->reset = devm_reset_control_get(&pdev->dev, "saradc-apb");
220 if (IS_ERR(info->reset)) {
221 ret = PTR_ERR(info->reset);
225 dev_dbg(&pdev->dev, "no reset control found\n");
229 init_completion(&info->completion);
231 irq = platform_get_irq(pdev, 0);
233 dev_err(&pdev->dev, "no irq resource?\n");
237 ret = devm_request_irq(&pdev->dev, irq, rockchip_saradc_isr,
238 0, dev_name(&pdev->dev), info);
240 dev_err(&pdev->dev, "failed requesting irq %d\n", irq);
244 info->pclk = devm_clk_get(&pdev->dev, "apb_pclk");
245 if (IS_ERR(info->pclk)) {
246 dev_err(&pdev->dev, "failed to get pclk\n");
247 return PTR_ERR(info->pclk);
250 info->clk = devm_clk_get(&pdev->dev, "saradc");
251 if (IS_ERR(info->clk)) {
252 dev_err(&pdev->dev, "failed to get adc clock\n");
253 return PTR_ERR(info->clk);
256 info->vref = devm_regulator_get(&pdev->dev, "vref");
257 if (IS_ERR(info->vref)) {
258 dev_err(&pdev->dev, "failed to get regulator, %ld\n",
259 PTR_ERR(info->vref));
260 return PTR_ERR(info->vref);
264 rockchip_saradc_reset_controller(info->reset);
267 * Use a default value for the converter clock.
268 * This may become user-configurable in the future.
270 ret = clk_set_rate(info->clk, info->data->clk_rate);
272 dev_err(&pdev->dev, "failed to set adc clk rate, %d\n", ret);
276 ret = regulator_enable(info->vref);
278 dev_err(&pdev->dev, "failed to enable vref regulator\n");
282 ret = clk_prepare_enable(info->pclk);
284 dev_err(&pdev->dev, "failed to enable pclk\n");
285 goto err_reg_voltage;
288 ret = clk_prepare_enable(info->clk);
290 dev_err(&pdev->dev, "failed to enable converter clock\n");
294 platform_set_drvdata(pdev, indio_dev);
296 indio_dev->name = dev_name(&pdev->dev);
297 indio_dev->dev.parent = &pdev->dev;
298 indio_dev->dev.of_node = pdev->dev.of_node;
299 indio_dev->info = &rockchip_saradc_iio_info;
300 indio_dev->modes = INDIO_DIRECT_MODE;
302 indio_dev->channels = info->data->channels;
303 indio_dev->num_channels = info->data->num_channels;
305 ret = iio_device_register(indio_dev);
312 clk_disable_unprepare(info->clk);
314 clk_disable_unprepare(info->pclk);
316 regulator_disable(info->vref);
320 static int rockchip_saradc_remove(struct platform_device *pdev)
322 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
323 struct rockchip_saradc *info = iio_priv(indio_dev);
325 iio_device_unregister(indio_dev);
326 clk_disable_unprepare(info->clk);
327 clk_disable_unprepare(info->pclk);
328 regulator_disable(info->vref);
333 #ifdef CONFIG_PM_SLEEP
334 static int rockchip_saradc_suspend(struct device *dev)
336 struct iio_dev *indio_dev = dev_get_drvdata(dev);
337 struct rockchip_saradc *info = iio_priv(indio_dev);
339 clk_disable_unprepare(info->clk);
340 clk_disable_unprepare(info->pclk);
341 regulator_disable(info->vref);
346 static int rockchip_saradc_resume(struct device *dev)
348 struct iio_dev *indio_dev = dev_get_drvdata(dev);
349 struct rockchip_saradc *info = iio_priv(indio_dev);
352 ret = regulator_enable(info->vref);
356 ret = clk_prepare_enable(info->pclk);
360 ret = clk_prepare_enable(info->clk);
368 static SIMPLE_DEV_PM_OPS(rockchip_saradc_pm_ops,
369 rockchip_saradc_suspend, rockchip_saradc_resume);
371 static struct platform_driver rockchip_saradc_driver = {
372 .probe = rockchip_saradc_probe,
373 .remove = rockchip_saradc_remove,
375 .name = "rockchip-saradc",
376 .of_match_table = rockchip_saradc_match,
377 .pm = &rockchip_saradc_pm_ops,
381 module_platform_driver(rockchip_saradc_driver);
383 MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
384 MODULE_DESCRIPTION("Rockchip SARADC driver");
385 MODULE_LICENSE("GPL v2");