/* ADC driver for sunxi platforms' (A10, A13 and A31) GPADC * * Copyright (c) 2016 Quentin Schulz <quentin.schulz@free-electrons.com> * * This program is free software; you can redistribute it and/or modify it under * the terms of the GNU General Public License version 2 as published by the * Free Software Foundation. * * The Allwinner SoCs all have an ADC that can also act as a touchscreen * controller and a thermal sensor. * The thermal sensor works only when the ADC acts as a touchscreen controller * and is configured to throw an interrupt every fixed periods of time (let say * every X seconds). * One would be tempted to disable the IP on the hardware side rather than * disabling interrupts to save some power but that resets the internal clock of * the IP, resulting in having to wait X seconds every time we want to read the * value of the thermal sensor. * This is also the reason of using autosuspend in pm_runtime. If there was no * autosuspend, the thermal sensor would need X seconds after every * pm_runtime_get_sync to get a value from the ADC. The autosuspend allows the * thermal sensor to be requested again in a certain time span before it gets * shutdown for not being used. */ #include <linux/completion.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/module.h> #include <linux/of.h> #include <linux/of_device.h> #include <linux/platform_device.h> #include <linux/pm_runtime.h> #include <linux/regmap.h> #include <linux/thermal.h> #include <linux/delay.h> #include <linux/iio/iio.h> #include <linux/iio/driver.h> #include <linux/iio/machine.h> #include <linux/mfd/sun4i-gpadc.h> static unsigned int sun4i_gpadc_chan_select(unsigned int chan) { return SUN4I_GPADC_CTRL1_ADC_CHAN_SELECT(chan); } static unsigned int sun6i_gpadc_chan_select(unsigned int chan) { return SUN6I_GPADC_CTRL1_ADC_CHAN_SELECT(chan); } struct gpadc_data { int temp_offset; int temp_scale; unsigned int tp_mode_en; unsigned int tp_adc_select; unsigned int (*adc_chan_select)(unsigned int chan); unsigned int adc_chan_mask; }; static const struct gpadc_data sun4i_gpadc_data = { .temp_offset = -1932, .temp_scale = 133, .tp_mode_en = SUN4I_GPADC_CTRL1_TP_MODE_EN, .tp_adc_select = SUN4I_GPADC_CTRL1_TP_ADC_SELECT, .adc_chan_select = &sun4i_gpadc_chan_select, .adc_chan_mask = SUN4I_GPADC_CTRL1_ADC_CHAN_MASK, }; static const struct gpadc_data sun5i_gpadc_data = { .temp_offset = -1447, .temp_scale = 100, .tp_mode_en = SUN4I_GPADC_CTRL1_TP_MODE_EN, .tp_adc_select = SUN4I_GPADC_CTRL1_TP_ADC_SELECT, .adc_chan_select = &sun4i_gpadc_chan_select, .adc_chan_mask = SUN4I_GPADC_CTRL1_ADC_CHAN_MASK, }; static const struct gpadc_data sun6i_gpadc_data = { .temp_offset = -1623, .temp_scale = 167, .tp_mode_en = SUN6I_GPADC_CTRL1_TP_MODE_EN, .tp_adc_select = SUN6I_GPADC_CTRL1_TP_ADC_SELECT, .adc_chan_select = &sun6i_gpadc_chan_select, .adc_chan_mask = SUN6I_GPADC_CTRL1_ADC_CHAN_MASK, }; static const struct gpadc_data sun8i_a33_gpadc_data = { .temp_offset = -1662, .temp_scale = 162, .tp_mode_en = SUN8I_GPADC_CTRL1_CHOP_TEMP_EN, }; struct sun4i_gpadc_iio { struct iio_dev *indio_dev; struct completion completion; int temp_data; u32 adc_data; struct regmap *regmap; unsigned int fifo_data_irq; atomic_t ignore_fifo_data_irq; unsigned int temp_data_irq; atomic_t ignore_temp_data_irq; const struct gpadc_data *data; bool no_irq; /* prevents concurrent reads of temperature and ADC */ struct mutex mutex; struct thermal_zone_device *tzd; struct device *sensor_device; }; #define SUN4I_GPADC_ADC_CHANNEL(_channel, _name) { \ .type = IIO_VOLTAGE, \ .indexed = 1, \ .channel = _channel, \ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ .datasheet_name = _name, \ } static struct iio_map sun4i_gpadc_hwmon_maps[] = { { .adc_channel_label = "temp_adc", .consumer_dev_name = "iio_hwmon.0", }, { /* sentinel */ }, }; static const struct iio_chan_spec sun4i_gpadc_channels[] = { SUN4I_GPADC_ADC_CHANNEL(0, "adc_chan0"), SUN4I_GPADC_ADC_CHANNEL(1, "adc_chan1"), SUN4I_GPADC_ADC_CHANNEL(2, "adc_chan2"), SUN4I_GPADC_ADC_CHANNEL(3, "adc_chan3"), { .type = IIO_TEMP, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_OFFSET), .datasheet_name = "temp_adc", }, }; static const struct iio_chan_spec sun4i_gpadc_channels_no_temp[] = { SUN4I_GPADC_ADC_CHANNEL(0, "adc_chan0"), SUN4I_GPADC_ADC_CHANNEL(1, "adc_chan1"), SUN4I_GPADC_ADC_CHANNEL(2, "adc_chan2"), SUN4I_GPADC_ADC_CHANNEL(3, "adc_chan3"), }; static const struct iio_chan_spec sun8i_a33_gpadc_channels[] = { { .type = IIO_TEMP, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_OFFSET), .datasheet_name = "temp_adc", }, }; static const struct regmap_config sun4i_gpadc_regmap_config = { .reg_bits = 32, .val_bits = 32, .reg_stride = 4, .fast_io = true, }; static int sun4i_prepare_for_irq(struct iio_dev *indio_dev, int channel, unsigned int irq) { struct sun4i_gpadc_iio *info = iio_priv(indio_dev); int ret; u32 reg; pm_runtime_get_sync(indio_dev->dev.parent); reinit_completion(&info->completion); ret = regmap_write(info->regmap, SUN4I_GPADC_INT_FIFOC, SUN4I_GPADC_INT_FIFOC_TP_FIFO_TRIG_LEVEL(1) | SUN4I_GPADC_INT_FIFOC_TP_FIFO_FLUSH); if (ret) return ret; ret = regmap_read(info->regmap, SUN4I_GPADC_CTRL1, ®); if (ret) return ret; if (irq == info->fifo_data_irq) { ret = regmap_write(info->regmap, SUN4I_GPADC_CTRL1, info->data->tp_mode_en | info->data->tp_adc_select | info->data->adc_chan_select(channel)); /* * When the IP changes channel, it needs a bit of time to get * correct values. */ if ((reg & info->data->adc_chan_mask) != info->data->adc_chan_select(channel)) mdelay(10); } else { /* * The temperature sensor returns valid data only when the ADC * operates in touchscreen mode. */ ret = regmap_write(info->regmap, SUN4I_GPADC_CTRL1, info->data->tp_mode_en); } if (ret) return ret; /* * When the IP changes mode between ADC or touchscreen, it * needs a bit of time to get correct values. */ if ((reg & info->data->tp_adc_select) != info->data->tp_adc_select) mdelay(100); return 0; } static int sun4i_gpadc_read(struct iio_dev *indio_dev, int channel, int *val, unsigned int irq) { struct sun4i_gpadc_iio *info = iio_priv(indio_dev); int ret; mutex_lock(&info->mutex); ret = sun4i_prepare_for_irq(indio_dev, channel, irq); if (ret) goto err; enable_irq(irq); /* * The temperature sensor throws an interruption periodically (currently * set at periods of ~0.6s in sun4i_gpadc_runtime_resume). A 1s delay * makes sure an interruption occurs in normal conditions. If it doesn't * occur, then there is a timeout. */ if (!wait_for_completion_timeout(&info->completion, msecs_to_jiffies(1000))) { ret = -ETIMEDOUT; goto err; } if (irq == info->fifo_data_irq) *val = info->adc_data; else *val = info->temp_data; ret = 0; pm_runtime_mark_last_busy(indio_dev->dev.parent); err: pm_runtime_put_autosuspend(indio_dev->dev.parent); disable_irq(irq); mutex_unlock(&info->mutex); return ret; } static int sun4i_gpadc_adc_read(struct iio_dev *indio_dev, int channel, int *val) { struct sun4i_gpadc_iio *info = iio_priv(indio_dev); return sun4i_gpadc_read(indio_dev, channel, val, info->fifo_data_irq); } static int sun4i_gpadc_temp_read(struct iio_dev *indio_dev, int *val) { struct sun4i_gpadc_iio *info = iio_priv(indio_dev); if (info->no_irq) { pm_runtime_get_sync(indio_dev->dev.parent); regmap_read(info->regmap, SUN4I_GPADC_TEMP_DATA, val); pm_runtime_mark_last_busy(indio_dev->dev.parent); pm_runtime_put_autosuspend(indio_dev->dev.parent); return 0; } return sun4i_gpadc_read(indio_dev, 0, val, info->temp_data_irq); } static int sun4i_gpadc_temp_offset(struct iio_dev *indio_dev, int *val) { struct sun4i_gpadc_iio *info = iio_priv(indio_dev); *val = info->data->temp_offset; return 0; } static int sun4i_gpadc_temp_scale(struct iio_dev *indio_dev, int *val) { struct sun4i_gpadc_iio *info = iio_priv(indio_dev); *val = info->data->temp_scale; return 0; } static int sun4i_gpadc_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { int ret; switch (mask) { case IIO_CHAN_INFO_OFFSET: ret = sun4i_gpadc_temp_offset(indio_dev, val); if (ret) return ret; return IIO_VAL_INT; case IIO_CHAN_INFO_RAW: if (chan->type == IIO_VOLTAGE) ret = sun4i_gpadc_adc_read(indio_dev, chan->channel, val); else ret = sun4i_gpadc_temp_read(indio_dev, val); if (ret) return ret; return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: if (chan->type == IIO_VOLTAGE) { /* 3000mV / 4096 * raw */ *val = 0; *val2 = 732421875; return IIO_VAL_INT_PLUS_NANO; } ret = sun4i_gpadc_temp_scale(indio_dev, val); if (ret) return ret; return IIO_VAL_INT; default: return -EINVAL; } return -EINVAL; } static const struct iio_info sun4i_gpadc_iio_info = { .read_raw = sun4i_gpadc_read_raw, }; static irqreturn_t sun4i_gpadc_temp_data_irq_handler(int irq, void *dev_id) { struct sun4i_gpadc_iio *info = dev_id; if (atomic_read(&info->ignore_temp_data_irq)) goto out; if (!regmap_read(info->regmap, SUN4I_GPADC_TEMP_DATA, &info->temp_data)) complete(&info->completion); out: return IRQ_HANDLED; } static irqreturn_t sun4i_gpadc_fifo_data_irq_handler(int irq, void *dev_id) { struct sun4i_gpadc_iio *info = dev_id; if (atomic_read(&info->ignore_fifo_data_irq)) goto out; if (!regmap_read(info->regmap, SUN4I_GPADC_DATA, &info->adc_data)) complete(&info->completion); out: return IRQ_HANDLED; } static int sun4i_gpadc_runtime_suspend(struct device *dev) { struct sun4i_gpadc_iio *info = iio_priv(dev_get_drvdata(dev)); /* Disable the ADC on IP */ regmap_write(info->regmap, SUN4I_GPADC_CTRL1, 0); /* Disable temperature sensor on IP */ regmap_write(info->regmap, SUN4I_GPADC_TPR, 0); return 0; } static int sun4i_gpadc_runtime_resume(struct device *dev) { struct sun4i_gpadc_iio *info = iio_priv(dev_get_drvdata(dev)); /* clkin = 6MHz */ regmap_write(info->regmap, SUN4I_GPADC_CTRL0, SUN4I_GPADC_CTRL0_ADC_CLK_DIVIDER(2) | SUN4I_GPADC_CTRL0_FS_DIV(7) | SUN4I_GPADC_CTRL0_T_ACQ(63)); regmap_write(info->regmap, SUN4I_GPADC_CTRL1, info->data->tp_mode_en); regmap_write(info->regmap, SUN4I_GPADC_CTRL3, SUN4I_GPADC_CTRL3_FILTER_EN | SUN4I_GPADC_CTRL3_FILTER_TYPE(1)); /* period = SUN4I_GPADC_TPR_TEMP_PERIOD * 256 * 16 / clkin; ~0.6s */ regmap_write(info->regmap, SUN4I_GPADC_TPR, SUN4I_GPADC_TPR_TEMP_ENABLE | SUN4I_GPADC_TPR_TEMP_PERIOD(800)); return 0; } static int sun4i_gpadc_get_temp(void *data, int *temp) { struct sun4i_gpadc_iio *info = data; int val, scale, offset; if (sun4i_gpadc_temp_read(info->indio_dev, &val)) return -ETIMEDOUT; sun4i_gpadc_temp_scale(info->indio_dev, &scale); sun4i_gpadc_temp_offset(info->indio_dev, &offset); *temp = (val + offset) * scale; return 0; } static const struct thermal_zone_of_device_ops sun4i_ts_tz_ops = { .get_temp = &sun4i_gpadc_get_temp, }; static const struct dev_pm_ops sun4i_gpadc_pm_ops = { .runtime_suspend = &sun4i_gpadc_runtime_suspend, .runtime_resume = &sun4i_gpadc_runtime_resume, }; static int sun4i_irq_init(struct platform_device *pdev, const char *name, irq_handler_t handler, const char *devname, unsigned int *irq, atomic_t *atomic) { int ret; struct sun4i_gpadc_dev *mfd_dev = dev_get_drvdata(pdev->dev.parent); struct sun4i_gpadc_iio *info = iio_priv(dev_get_drvdata(&pdev->dev)); /* * Once the interrupt is activated, the IP continuously performs * conversions thus throws interrupts. The interrupt is activated right * after being requested but we want to control when these interrupts * occur thus we disable it right after being requested. However, an * interrupt might occur between these two instructions and we have to * make sure that does not happen, by using atomic flags. We set the * flag before requesting the interrupt and unset it right after * disabling the interrupt. When an interrupt occurs between these two * instructions, reading the atomic flag will tell us to ignore the * interrupt. */ atomic_set(atomic, 1); ret = platform_get_irq_byname(pdev, name); if (ret < 0) { dev_err(&pdev->dev, "no %s interrupt registered\n", name); return ret; } ret = regmap_irq_get_virq(mfd_dev->regmap_irqc, ret); if (ret < 0) { dev_err(&pdev->dev, "failed to get virq for irq %s\n", name); return ret; } *irq = ret; ret = devm_request_any_context_irq(&pdev->dev, *irq, handler, 0, devname, info); if (ret < 0) { dev_err(&pdev->dev, "could not request %s interrupt: %d\n", name, ret); return ret; } disable_irq(*irq); atomic_set(atomic, 0); return 0; } static const struct of_device_id sun4i_gpadc_of_id[] = { { .compatible = "allwinner,sun8i-a33-ths", .data = &sun8i_a33_gpadc_data, }, { /* sentinel */ } }; static int sun4i_gpadc_probe_dt(struct platform_device *pdev, struct iio_dev *indio_dev) { struct sun4i_gpadc_iio *info = iio_priv(indio_dev); struct resource *mem; void __iomem *base; int ret; info->data = of_device_get_match_data(&pdev->dev); if (!info->data) return -ENODEV; info->no_irq = true; indio_dev->num_channels = ARRAY_SIZE(sun8i_a33_gpadc_channels); indio_dev->channels = sun8i_a33_gpadc_channels; mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); base = devm_ioremap_resource(&pdev->dev, mem); if (IS_ERR(base)) return PTR_ERR(base); info->regmap = devm_regmap_init_mmio(&pdev->dev, base, &sun4i_gpadc_regmap_config); if (IS_ERR(info->regmap)) { ret = PTR_ERR(info->regmap); dev_err(&pdev->dev, "failed to init regmap: %d\n", ret); return ret; } if (IS_ENABLED(CONFIG_THERMAL_OF)) info->sensor_device = &pdev->dev; return 0; } static int sun4i_gpadc_probe_mfd(struct platform_device *pdev, struct iio_dev *indio_dev) { struct sun4i_gpadc_iio *info = iio_priv(indio_dev); struct sun4i_gpadc_dev *sun4i_gpadc_dev = dev_get_drvdata(pdev->dev.parent); int ret; info->no_irq = false; info->regmap = sun4i_gpadc_dev->regmap; indio_dev->num_channels = ARRAY_SIZE(sun4i_gpadc_channels); indio_dev->channels = sun4i_gpadc_channels; info->data = (struct gpadc_data *)platform_get_device_id(pdev)->driver_data; /* * Since the controller needs to be in touchscreen mode for its thermal * sensor to operate properly, and that switching between the two modes * needs a delay, always registering in the thermal framework will * significantly slow down the conversion rate of the ADCs. * * Therefore, instead of depending on THERMAL_OF in Kconfig, we only * register the sensor if that option is enabled, eventually leaving * that choice to the user. */ if (IS_ENABLED(CONFIG_THERMAL_OF)) { /* * This driver is a child of an MFD which has a node in the DT * but not its children, because of DT backward compatibility * for A10, A13 and A31 SoCs. Therefore, the resulting devices * of this driver do not have an of_node variable. * However, its parent (the MFD driver) has an of_node variable * and since devm_thermal_zone_of_sensor_register uses its first * argument to match the phandle defined in the node of the * thermal driver with the of_node of the device passed as first * argument and the third argument to call ops from * thermal_zone_of_device_ops, the solution is to use the parent * device as first argument to match the phandle with its * of_node, and the device from this driver as third argument to * return the temperature. */ info->sensor_device = pdev->dev.parent; } else { indio_dev->num_channels = ARRAY_SIZE(sun4i_gpadc_channels_no_temp); indio_dev->channels = sun4i_gpadc_channels_no_temp; } if (IS_ENABLED(CONFIG_THERMAL_OF)) { ret = sun4i_irq_init(pdev, "TEMP_DATA_PENDING", sun4i_gpadc_temp_data_irq_handler, "temp_data", &info->temp_data_irq, &info->ignore_temp_data_irq); if (ret < 0) return ret; } ret = sun4i_irq_init(pdev, "FIFO_DATA_PENDING", sun4i_gpadc_fifo_data_irq_handler, "fifo_data", &info->fifo_data_irq, &info->ignore_fifo_data_irq); if (ret < 0) return ret; if (IS_ENABLED(CONFIG_THERMAL_OF)) { ret = iio_map_array_register(indio_dev, sun4i_gpadc_hwmon_maps); if (ret < 0) { dev_err(&pdev->dev, "failed to register iio map array\n"); return ret; } } return 0; } static int sun4i_gpadc_probe(struct platform_device *pdev) { struct sun4i_gpadc_iio *info; struct iio_dev *indio_dev; int ret; indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info)); if (!indio_dev) return -ENOMEM; info = iio_priv(indio_dev); platform_set_drvdata(pdev, indio_dev); mutex_init(&info->mutex); info->indio_dev = indio_dev; init_completion(&info->completion); indio_dev->name = dev_name(&pdev->dev); indio_dev->dev.parent = &pdev->dev; indio_dev->dev.of_node = pdev->dev.of_node; indio_dev->info = &sun4i_gpadc_iio_info; indio_dev->modes = INDIO_DIRECT_MODE; if (pdev->dev.of_node) ret = sun4i_gpadc_probe_dt(pdev, indio_dev); else ret = sun4i_gpadc_probe_mfd(pdev, indio_dev); if (ret) return ret; pm_runtime_set_autosuspend_delay(&pdev->dev, SUN4I_GPADC_AUTOSUSPEND_DELAY); pm_runtime_use_autosuspend(&pdev->dev); pm_runtime_set_suspended(&pdev->dev); pm_runtime_enable(&pdev->dev); if (IS_ENABLED(CONFIG_THERMAL_OF)) { info->tzd = thermal_zone_of_sensor_register(info->sensor_device, 0, info, &sun4i_ts_tz_ops); /* * Do not fail driver probing when failing to register in * thermal because no thermal DT node is found. */ if (IS_ERR(info->tzd) && PTR_ERR(info->tzd) != -ENODEV) { dev_err(&pdev->dev, "could not register thermal sensor: %ld\n", PTR_ERR(info->tzd)); return PTR_ERR(info->tzd); } } ret = devm_iio_device_register(&pdev->dev, indio_dev); if (ret < 0) { dev_err(&pdev->dev, "could not register the device\n"); goto err_map; } return 0; err_map: if (!info->no_irq && IS_ENABLED(CONFIG_THERMAL_OF)) iio_map_array_unregister(indio_dev); pm_runtime_put(&pdev->dev); pm_runtime_disable(&pdev->dev); return ret; } static int sun4i_gpadc_remove(struct platform_device *pdev) { struct iio_dev *indio_dev = platform_get_drvdata(pdev); struct sun4i_gpadc_iio *info = iio_priv(indio_dev); pm_runtime_put(&pdev->dev); pm_runtime_disable(&pdev->dev); if (!IS_ENABLED(CONFIG_THERMAL_OF)) return 0; thermal_zone_of_sensor_unregister(info->sensor_device, info->tzd); if (!info->no_irq) iio_map_array_unregister(indio_dev); return 0; } static const struct platform_device_id sun4i_gpadc_id[] = { { "sun4i-a10-gpadc-iio", (kernel_ulong_t)&sun4i_gpadc_data }, { "sun5i-a13-gpadc-iio", (kernel_ulong_t)&sun5i_gpadc_data }, { "sun6i-a31-gpadc-iio", (kernel_ulong_t)&sun6i_gpadc_data }, { /* sentinel */ }, }; MODULE_DEVICE_TABLE(platform, sun4i_gpadc_id); static struct platform_driver sun4i_gpadc_driver = { .driver = { .name = "sun4i-gpadc-iio", .of_match_table = sun4i_gpadc_of_id, .pm = &sun4i_gpadc_pm_ops, }, .id_table = sun4i_gpadc_id, .probe = sun4i_gpadc_probe, .remove = sun4i_gpadc_remove, }; MODULE_DEVICE_TABLE(of, sun4i_gpadc_of_id); module_platform_driver(sun4i_gpadc_driver); MODULE_DESCRIPTION("ADC driver for sunxi platforms"); MODULE_AUTHOR("Quentin Schulz <quentin.schulz@free-electrons.com>"); MODULE_LICENSE("GPL v2");