1 // SPDX-License-Identifier: GPL-2.0
2 /* ADC driver for sunxi platforms' (A10, A13 and A31) GPADC
4 * Copyright (c) 2016 Quentin Schulz <quentin.schulz@free-electrons.com>
6 * The Allwinner SoCs all have an ADC that can also act as a touchscreen
7 * controller and a thermal sensor.
8 * The thermal sensor works only when the ADC acts as a touchscreen controller
9 * and is configured to throw an interrupt every fixed periods of time (let say
11 * One would be tempted to disable the IP on the hardware side rather than
12 * disabling interrupts to save some power but that resets the internal clock of
13 * the IP, resulting in having to wait X seconds every time we want to read the
14 * value of the thermal sensor.
15 * This is also the reason of using autosuspend in pm_runtime. If there was no
16 * autosuspend, the thermal sensor would need X seconds after every
17 * pm_runtime_get_sync to get a value from the ADC. The autosuspend allows the
18 * thermal sensor to be requested again in a certain time span before it gets
19 * shutdown for not being used.
22 #include <linux/completion.h>
23 #include <linux/interrupt.h>
25 #include <linux/module.h>
27 #include <linux/platform_device.h>
28 #include <linux/pm_runtime.h>
29 #include <linux/regmap.h>
30 #include <linux/thermal.h>
31 #include <linux/delay.h>
33 #include <linux/iio/iio.h>
34 #include <linux/iio/driver.h>
35 #include <linux/iio/machine.h>
36 #include <linux/mfd/sun4i-gpadc.h>
38 static unsigned int sun4i_gpadc_chan_select(unsigned int chan)
40 return SUN4I_GPADC_CTRL1_ADC_CHAN_SELECT(chan);
43 static unsigned int sun6i_gpadc_chan_select(unsigned int chan)
45 return SUN6I_GPADC_CTRL1_ADC_CHAN_SELECT(chan);
51 unsigned int tp_mode_en;
52 unsigned int tp_adc_select;
53 unsigned int (*adc_chan_select)(unsigned int chan);
54 unsigned int adc_chan_mask;
57 static const struct gpadc_data sun4i_gpadc_data = {
60 .tp_mode_en = SUN4I_GPADC_CTRL1_TP_MODE_EN,
61 .tp_adc_select = SUN4I_GPADC_CTRL1_TP_ADC_SELECT,
62 .adc_chan_select = &sun4i_gpadc_chan_select,
63 .adc_chan_mask = SUN4I_GPADC_CTRL1_ADC_CHAN_MASK,
66 static const struct gpadc_data sun5i_gpadc_data = {
69 .tp_mode_en = SUN4I_GPADC_CTRL1_TP_MODE_EN,
70 .tp_adc_select = SUN4I_GPADC_CTRL1_TP_ADC_SELECT,
71 .adc_chan_select = &sun4i_gpadc_chan_select,
72 .adc_chan_mask = SUN4I_GPADC_CTRL1_ADC_CHAN_MASK,
75 static const struct gpadc_data sun6i_gpadc_data = {
78 .tp_mode_en = SUN6I_GPADC_CTRL1_TP_MODE_EN,
79 .tp_adc_select = SUN6I_GPADC_CTRL1_TP_ADC_SELECT,
80 .adc_chan_select = &sun6i_gpadc_chan_select,
81 .adc_chan_mask = SUN6I_GPADC_CTRL1_ADC_CHAN_MASK,
84 static const struct gpadc_data sun8i_a33_gpadc_data = {
87 .tp_mode_en = SUN8I_GPADC_CTRL1_CHOP_TEMP_EN,
90 struct sun4i_gpadc_iio {
91 struct iio_dev *indio_dev;
92 struct completion completion;
95 struct regmap *regmap;
96 unsigned int fifo_data_irq;
97 atomic_t ignore_fifo_data_irq;
98 unsigned int temp_data_irq;
99 atomic_t ignore_temp_data_irq;
100 const struct gpadc_data *data;
102 /* prevents concurrent reads of temperature and ADC */
104 struct thermal_zone_device *tzd;
105 struct device *sensor_device;
108 #define SUN4I_GPADC_ADC_CHANNEL(_channel, _name) { \
109 .type = IIO_VOLTAGE, \
111 .channel = _channel, \
112 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
113 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
114 .datasheet_name = _name, \
117 static struct iio_map sun4i_gpadc_hwmon_maps[] = {
119 .adc_channel_label = "temp_adc",
120 .consumer_dev_name = "iio_hwmon.0",
125 static const struct iio_chan_spec sun4i_gpadc_channels[] = {
126 SUN4I_GPADC_ADC_CHANNEL(0, "adc_chan0"),
127 SUN4I_GPADC_ADC_CHANNEL(1, "adc_chan1"),
128 SUN4I_GPADC_ADC_CHANNEL(2, "adc_chan2"),
129 SUN4I_GPADC_ADC_CHANNEL(3, "adc_chan3"),
132 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
133 BIT(IIO_CHAN_INFO_SCALE) |
134 BIT(IIO_CHAN_INFO_OFFSET),
135 .datasheet_name = "temp_adc",
139 static const struct iio_chan_spec sun4i_gpadc_channels_no_temp[] = {
140 SUN4I_GPADC_ADC_CHANNEL(0, "adc_chan0"),
141 SUN4I_GPADC_ADC_CHANNEL(1, "adc_chan1"),
142 SUN4I_GPADC_ADC_CHANNEL(2, "adc_chan2"),
143 SUN4I_GPADC_ADC_CHANNEL(3, "adc_chan3"),
146 static const struct iio_chan_spec sun8i_a33_gpadc_channels[] = {
149 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
150 BIT(IIO_CHAN_INFO_SCALE) |
151 BIT(IIO_CHAN_INFO_OFFSET),
152 .datasheet_name = "temp_adc",
156 static const struct regmap_config sun4i_gpadc_regmap_config = {
163 static int sun4i_prepare_for_irq(struct iio_dev *indio_dev, int channel,
166 struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
170 pm_runtime_get_sync(indio_dev->dev.parent);
172 reinit_completion(&info->completion);
174 ret = regmap_write(info->regmap, SUN4I_GPADC_INT_FIFOC,
175 SUN4I_GPADC_INT_FIFOC_TP_FIFO_TRIG_LEVEL(1) |
176 SUN4I_GPADC_INT_FIFOC_TP_FIFO_FLUSH);
180 ret = regmap_read(info->regmap, SUN4I_GPADC_CTRL1, ®);
184 if (irq == info->fifo_data_irq) {
185 ret = regmap_write(info->regmap, SUN4I_GPADC_CTRL1,
186 info->data->tp_mode_en |
187 info->data->tp_adc_select |
188 info->data->adc_chan_select(channel));
190 * When the IP changes channel, it needs a bit of time to get
193 if ((reg & info->data->adc_chan_mask) !=
194 info->data->adc_chan_select(channel))
199 * The temperature sensor returns valid data only when the ADC
200 * operates in touchscreen mode.
202 ret = regmap_write(info->regmap, SUN4I_GPADC_CTRL1,
203 info->data->tp_mode_en);
210 * When the IP changes mode between ADC or touchscreen, it
211 * needs a bit of time to get correct values.
213 if ((reg & info->data->tp_adc_select) != info->data->tp_adc_select)
219 static int sun4i_gpadc_read(struct iio_dev *indio_dev, int channel, int *val,
222 struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
225 mutex_lock(&info->mutex);
227 ret = sun4i_prepare_for_irq(indio_dev, channel, irq);
234 * The temperature sensor throws an interruption periodically (currently
235 * set at periods of ~0.6s in sun4i_gpadc_runtime_resume). A 1s delay
236 * makes sure an interruption occurs in normal conditions. If it doesn't
237 * occur, then there is a timeout.
239 if (!wait_for_completion_timeout(&info->completion,
240 msecs_to_jiffies(1000))) {
245 if (irq == info->fifo_data_irq)
246 *val = info->adc_data;
248 *val = info->temp_data;
251 pm_runtime_mark_last_busy(indio_dev->dev.parent);
254 pm_runtime_put_autosuspend(indio_dev->dev.parent);
256 mutex_unlock(&info->mutex);
261 static int sun4i_gpadc_adc_read(struct iio_dev *indio_dev, int channel,
264 struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
266 return sun4i_gpadc_read(indio_dev, channel, val, info->fifo_data_irq);
269 static int sun4i_gpadc_temp_read(struct iio_dev *indio_dev, int *val)
271 struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
274 pm_runtime_get_sync(indio_dev->dev.parent);
276 regmap_read(info->regmap, SUN4I_GPADC_TEMP_DATA, val);
278 pm_runtime_mark_last_busy(indio_dev->dev.parent);
279 pm_runtime_put_autosuspend(indio_dev->dev.parent);
284 return sun4i_gpadc_read(indio_dev, 0, val, info->temp_data_irq);
287 static int sun4i_gpadc_temp_offset(struct iio_dev *indio_dev, int *val)
289 struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
291 *val = info->data->temp_offset;
296 static int sun4i_gpadc_temp_scale(struct iio_dev *indio_dev, int *val)
298 struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
300 *val = info->data->temp_scale;
305 static int sun4i_gpadc_read_raw(struct iio_dev *indio_dev,
306 struct iio_chan_spec const *chan, int *val,
307 int *val2, long mask)
312 case IIO_CHAN_INFO_OFFSET:
313 ret = sun4i_gpadc_temp_offset(indio_dev, val);
318 case IIO_CHAN_INFO_RAW:
319 if (chan->type == IIO_VOLTAGE)
320 ret = sun4i_gpadc_adc_read(indio_dev, chan->channel,
323 ret = sun4i_gpadc_temp_read(indio_dev, val);
329 case IIO_CHAN_INFO_SCALE:
330 if (chan->type == IIO_VOLTAGE) {
331 /* 3000mV / 4096 * raw */
334 return IIO_VAL_INT_PLUS_NANO;
337 ret = sun4i_gpadc_temp_scale(indio_dev, val);
349 static const struct iio_info sun4i_gpadc_iio_info = {
350 .read_raw = sun4i_gpadc_read_raw,
353 static irqreturn_t sun4i_gpadc_temp_data_irq_handler(int irq, void *dev_id)
355 struct sun4i_gpadc_iio *info = dev_id;
357 if (atomic_read(&info->ignore_temp_data_irq))
360 if (!regmap_read(info->regmap, SUN4I_GPADC_TEMP_DATA, &info->temp_data))
361 complete(&info->completion);
367 static irqreturn_t sun4i_gpadc_fifo_data_irq_handler(int irq, void *dev_id)
369 struct sun4i_gpadc_iio *info = dev_id;
371 if (atomic_read(&info->ignore_fifo_data_irq))
374 if (!regmap_read(info->regmap, SUN4I_GPADC_DATA, &info->adc_data))
375 complete(&info->completion);
381 static int sun4i_gpadc_runtime_suspend(struct device *dev)
383 struct sun4i_gpadc_iio *info = iio_priv(dev_get_drvdata(dev));
385 /* Disable the ADC on IP */
386 regmap_write(info->regmap, SUN4I_GPADC_CTRL1, 0);
387 /* Disable temperature sensor on IP */
388 regmap_write(info->regmap, SUN4I_GPADC_TPR, 0);
393 static int sun4i_gpadc_runtime_resume(struct device *dev)
395 struct sun4i_gpadc_iio *info = iio_priv(dev_get_drvdata(dev));
398 regmap_write(info->regmap, SUN4I_GPADC_CTRL0,
399 SUN4I_GPADC_CTRL0_ADC_CLK_DIVIDER(2) |
400 SUN4I_GPADC_CTRL0_FS_DIV(7) |
401 SUN4I_GPADC_CTRL0_T_ACQ(63));
402 regmap_write(info->regmap, SUN4I_GPADC_CTRL1, info->data->tp_mode_en);
403 regmap_write(info->regmap, SUN4I_GPADC_CTRL3,
404 SUN4I_GPADC_CTRL3_FILTER_EN |
405 SUN4I_GPADC_CTRL3_FILTER_TYPE(1));
406 /* period = SUN4I_GPADC_TPR_TEMP_PERIOD * 256 * 16 / clkin; ~0.6s */
407 regmap_write(info->regmap, SUN4I_GPADC_TPR,
408 SUN4I_GPADC_TPR_TEMP_ENABLE |
409 SUN4I_GPADC_TPR_TEMP_PERIOD(800));
414 static int sun4i_gpadc_get_temp(struct thermal_zone_device *tz, int *temp)
416 struct sun4i_gpadc_iio *info = thermal_zone_device_priv(tz);
417 int val, scale, offset;
419 if (sun4i_gpadc_temp_read(info->indio_dev, &val))
422 sun4i_gpadc_temp_scale(info->indio_dev, &scale);
423 sun4i_gpadc_temp_offset(info->indio_dev, &offset);
425 *temp = (val + offset) * scale;
430 static const struct thermal_zone_device_ops sun4i_ts_tz_ops = {
431 .get_temp = &sun4i_gpadc_get_temp,
434 static const struct dev_pm_ops sun4i_gpadc_pm_ops = {
435 .runtime_suspend = &sun4i_gpadc_runtime_suspend,
436 .runtime_resume = &sun4i_gpadc_runtime_resume,
439 static int sun4i_irq_init(struct platform_device *pdev, const char *name,
440 irq_handler_t handler, const char *devname,
441 unsigned int *irq, atomic_t *atomic)
444 struct sun4i_gpadc_dev *mfd_dev = dev_get_drvdata(pdev->dev.parent);
445 struct sun4i_gpadc_iio *info = iio_priv(dev_get_drvdata(&pdev->dev));
448 * Once the interrupt is activated, the IP continuously performs
449 * conversions thus throws interrupts. The interrupt is activated right
450 * after being requested but we want to control when these interrupts
451 * occur thus we disable it right after being requested. However, an
452 * interrupt might occur between these two instructions and we have to
453 * make sure that does not happen, by using atomic flags. We set the
454 * flag before requesting the interrupt and unset it right after
455 * disabling the interrupt. When an interrupt occurs between these two
456 * instructions, reading the atomic flag will tell us to ignore the
459 atomic_set(atomic, 1);
461 ret = platform_get_irq_byname(pdev, name);
465 ret = regmap_irq_get_virq(mfd_dev->regmap_irqc, ret);
467 dev_err(&pdev->dev, "failed to get virq for irq %s\n", name);
472 ret = devm_request_any_context_irq(&pdev->dev, *irq, handler,
476 dev_err(&pdev->dev, "could not request %s interrupt: %d\n",
481 atomic_set(atomic, 0);
486 static const struct of_device_id sun4i_gpadc_of_id[] = {
488 .compatible = "allwinner,sun8i-a33-ths",
489 .data = &sun8i_a33_gpadc_data,
494 static int sun4i_gpadc_probe_dt(struct platform_device *pdev,
495 struct iio_dev *indio_dev)
497 struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
501 info->data = of_device_get_match_data(&pdev->dev);
506 indio_dev->num_channels = ARRAY_SIZE(sun8i_a33_gpadc_channels);
507 indio_dev->channels = sun8i_a33_gpadc_channels;
509 base = devm_platform_ioremap_resource(pdev, 0);
511 return PTR_ERR(base);
513 info->regmap = devm_regmap_init_mmio(&pdev->dev, base,
514 &sun4i_gpadc_regmap_config);
515 if (IS_ERR(info->regmap)) {
516 ret = PTR_ERR(info->regmap);
517 dev_err(&pdev->dev, "failed to init regmap: %d\n", ret);
521 if (IS_ENABLED(CONFIG_THERMAL_OF))
522 info->sensor_device = &pdev->dev;
527 static int sun4i_gpadc_probe_mfd(struct platform_device *pdev,
528 struct iio_dev *indio_dev)
530 struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
531 struct sun4i_gpadc_dev *sun4i_gpadc_dev =
532 dev_get_drvdata(pdev->dev.parent);
535 info->no_irq = false;
536 info->regmap = sun4i_gpadc_dev->regmap;
538 indio_dev->num_channels = ARRAY_SIZE(sun4i_gpadc_channels);
539 indio_dev->channels = sun4i_gpadc_channels;
541 info->data = (struct gpadc_data *)platform_get_device_id(pdev)->driver_data;
544 * Since the controller needs to be in touchscreen mode for its thermal
545 * sensor to operate properly, and that switching between the two modes
546 * needs a delay, always registering in the thermal framework will
547 * significantly slow down the conversion rate of the ADCs.
549 * Therefore, instead of depending on THERMAL_OF in Kconfig, we only
550 * register the sensor if that option is enabled, eventually leaving
551 * that choice to the user.
554 if (IS_ENABLED(CONFIG_THERMAL_OF)) {
556 * This driver is a child of an MFD which has a node in the DT
557 * but not its children, because of DT backward compatibility
558 * for A10, A13 and A31 SoCs. Therefore, the resulting devices
559 * of this driver do not have an of_node variable.
560 * However, its parent (the MFD driver) has an of_node variable
561 * and since devm_thermal_zone_of_sensor_register uses its first
562 * argument to match the phandle defined in the node of the
563 * thermal driver with the of_node of the device passed as first
564 * argument and the third argument to call ops from
565 * thermal_zone_of_device_ops, the solution is to use the parent
566 * device as first argument to match the phandle with its
567 * of_node, and the device from this driver as third argument to
568 * return the temperature.
570 info->sensor_device = pdev->dev.parent;
572 indio_dev->num_channels =
573 ARRAY_SIZE(sun4i_gpadc_channels_no_temp);
574 indio_dev->channels = sun4i_gpadc_channels_no_temp;
577 if (IS_ENABLED(CONFIG_THERMAL_OF)) {
578 ret = sun4i_irq_init(pdev, "TEMP_DATA_PENDING",
579 sun4i_gpadc_temp_data_irq_handler,
580 "temp_data", &info->temp_data_irq,
581 &info->ignore_temp_data_irq);
586 ret = sun4i_irq_init(pdev, "FIFO_DATA_PENDING",
587 sun4i_gpadc_fifo_data_irq_handler, "fifo_data",
588 &info->fifo_data_irq, &info->ignore_fifo_data_irq);
592 if (IS_ENABLED(CONFIG_THERMAL_OF)) {
593 ret = iio_map_array_register(indio_dev, sun4i_gpadc_hwmon_maps);
596 "failed to register iio map array\n");
604 static int sun4i_gpadc_probe(struct platform_device *pdev)
606 struct sun4i_gpadc_iio *info;
607 struct iio_dev *indio_dev;
610 indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info));
614 info = iio_priv(indio_dev);
615 platform_set_drvdata(pdev, indio_dev);
617 mutex_init(&info->mutex);
618 info->indio_dev = indio_dev;
619 init_completion(&info->completion);
620 indio_dev->name = dev_name(&pdev->dev);
621 indio_dev->info = &sun4i_gpadc_iio_info;
622 indio_dev->modes = INDIO_DIRECT_MODE;
624 if (pdev->dev.of_node)
625 ret = sun4i_gpadc_probe_dt(pdev, indio_dev);
627 ret = sun4i_gpadc_probe_mfd(pdev, indio_dev);
632 pm_runtime_set_autosuspend_delay(&pdev->dev,
633 SUN4I_GPADC_AUTOSUSPEND_DELAY);
634 pm_runtime_use_autosuspend(&pdev->dev);
635 pm_runtime_set_suspended(&pdev->dev);
636 pm_runtime_enable(&pdev->dev);
638 if (IS_ENABLED(CONFIG_THERMAL_OF)) {
639 info->tzd = devm_thermal_of_zone_register(info->sensor_device,
643 * Do not fail driver probing when failing to register in
644 * thermal because no thermal DT node is found.
646 if (IS_ERR(info->tzd) && PTR_ERR(info->tzd) != -ENODEV) {
648 "could not register thermal sensor: %ld\n",
650 return PTR_ERR(info->tzd);
654 ret = devm_iio_device_register(&pdev->dev, indio_dev);
656 dev_err(&pdev->dev, "could not register the device\n");
663 if (!info->no_irq && IS_ENABLED(CONFIG_THERMAL_OF))
664 iio_map_array_unregister(indio_dev);
666 pm_runtime_put(&pdev->dev);
667 pm_runtime_disable(&pdev->dev);
672 static void sun4i_gpadc_remove(struct platform_device *pdev)
674 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
675 struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
677 pm_runtime_put(&pdev->dev);
678 pm_runtime_disable(&pdev->dev);
680 if (!IS_ENABLED(CONFIG_THERMAL_OF))
684 iio_map_array_unregister(indio_dev);
687 static const struct platform_device_id sun4i_gpadc_id[] = {
688 { "sun4i-a10-gpadc-iio", (kernel_ulong_t)&sun4i_gpadc_data },
689 { "sun5i-a13-gpadc-iio", (kernel_ulong_t)&sun5i_gpadc_data },
690 { "sun6i-a31-gpadc-iio", (kernel_ulong_t)&sun6i_gpadc_data },
693 MODULE_DEVICE_TABLE(platform, sun4i_gpadc_id);
695 static struct platform_driver sun4i_gpadc_driver = {
697 .name = "sun4i-gpadc-iio",
698 .of_match_table = sun4i_gpadc_of_id,
699 .pm = &sun4i_gpadc_pm_ops,
701 .id_table = sun4i_gpadc_id,
702 .probe = sun4i_gpadc_probe,
703 .remove_new = sun4i_gpadc_remove,
705 MODULE_DEVICE_TABLE(of, sun4i_gpadc_of_id);
707 module_platform_driver(sun4i_gpadc_driver);
709 MODULE_DESCRIPTION("ADC driver for sunxi platforms");
710 MODULE_AUTHOR("Quentin Schulz <quentin.schulz@free-electrons.com>");
711 MODULE_LICENSE("GPL v2");