diff options
Diffstat (limited to 'drivers/iio/adc/mt6360-adc.c')
| -rw-r--r-- | drivers/iio/adc/mt6360-adc.c | 373 |
1 files changed, 373 insertions, 0 deletions
diff --git a/drivers/iio/adc/mt6360-adc.c b/drivers/iio/adc/mt6360-adc.c new file mode 100644 index 0000000000..3710473e52 --- /dev/null +++ b/drivers/iio/adc/mt6360-adc.c @@ -0,0 +1,373 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/bits.h> +#include <linux/delay.h> +#include <linux/irq.h> +#include <linux/kernel.h> +#include <linux/ktime.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> + +#include <linux/iio/buffer.h> +#include <linux/iio/iio.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/iio/triggered_buffer.h> + +#include <asm/unaligned.h> + +#define MT6360_REG_PMUCHGCTRL3 0x313 +#define MT6360_REG_PMUADCCFG 0x356 +#define MT6360_REG_PMUADCIDLET 0x358 +#define MT6360_REG_PMUADCRPT1 0x35A + +/* PMUCHGCTRL3 0x313 */ +#define MT6360_AICR_MASK GENMASK(7, 2) +#define MT6360_AICR_SHFT 2 +#define MT6360_AICR_400MA 0x6 +/* PMUADCCFG 0x356 */ +#define MT6360_ADCEN_MASK BIT(15) +/* PMUADCRPT1 0x35A */ +#define MT6360_PREFERCH_MASK GENMASK(7, 4) +#define MT6360_PREFERCH_SHFT 4 +#define MT6360_RPTCH_MASK GENMASK(3, 0) +#define MT6360_NO_PREFER 15 + +/* Time in ms */ +#define ADC_WAIT_TIME_MS 25 +#define ADC_CONV_TIMEOUT_MS 100 +#define ADC_LOOP_TIME_US 2000 + +enum { + MT6360_CHAN_USBID = 0, + MT6360_CHAN_VBUSDIV5, + MT6360_CHAN_VBUSDIV2, + MT6360_CHAN_VSYS, + MT6360_CHAN_VBAT, + MT6360_CHAN_IBUS, + MT6360_CHAN_IBAT, + MT6360_CHAN_CHG_VDDP, + MT6360_CHAN_TEMP_JC, + MT6360_CHAN_VREF_TS, + MT6360_CHAN_TS, + MT6360_CHAN_MAX +}; + +struct mt6360_adc_data { + struct device *dev; + struct regmap *regmap; + /* Due to only one set of ADC control, this lock is used to prevent the race condition */ + struct mutex adc_lock; + ktime_t last_off_timestamps[MT6360_CHAN_MAX]; +}; + +static int mt6360_adc_read_channel(struct mt6360_adc_data *mad, int channel, int *val) +{ + __be16 adc_enable; + u8 rpt[3]; + ktime_t predict_end_t, timeout; + unsigned int pre_wait_time; + int ret; + + mutex_lock(&mad->adc_lock); + + /* Select the preferred ADC channel */ + ret = regmap_update_bits(mad->regmap, MT6360_REG_PMUADCRPT1, MT6360_PREFERCH_MASK, + channel << MT6360_PREFERCH_SHFT); + if (ret) + goto out_adc_lock; + + adc_enable = cpu_to_be16(MT6360_ADCEN_MASK | BIT(channel)); + ret = regmap_raw_write(mad->regmap, MT6360_REG_PMUADCCFG, &adc_enable, sizeof(adc_enable)); + if (ret) + goto out_adc_lock; + + predict_end_t = ktime_add_ms(mad->last_off_timestamps[channel], 2 * ADC_WAIT_TIME_MS); + + if (ktime_after(ktime_get(), predict_end_t)) + pre_wait_time = ADC_WAIT_TIME_MS; + else + pre_wait_time = 3 * ADC_WAIT_TIME_MS; + + if (msleep_interruptible(pre_wait_time)) { + ret = -ERESTARTSYS; + goto out_adc_conv; + } + + timeout = ktime_add_ms(ktime_get(), ADC_CONV_TIMEOUT_MS); + while (true) { + ret = regmap_raw_read(mad->regmap, MT6360_REG_PMUADCRPT1, rpt, sizeof(rpt)); + if (ret) + goto out_adc_conv; + + /* + * There are two functions, ZCV and TypeC OTP, running ADC VBAT and TS in + * background, and ADC samples are taken on a fixed frequency no matter read the + * previous one or not. + * To avoid conflict, We set minimum time threshold after enable ADC and + * check report channel is the same. + * The worst case is run the same ADC twice and background function is also running, + * ADC conversion sequence is desire channel before start ADC, background ADC, + * desire channel after start ADC. + * So the minimum correct data is three times of typical conversion time. + */ + if ((rpt[0] & MT6360_RPTCH_MASK) == channel) + break; + + if (ktime_compare(ktime_get(), timeout) > 0) { + ret = -ETIMEDOUT; + goto out_adc_conv; + } + + usleep_range(ADC_LOOP_TIME_US / 2, ADC_LOOP_TIME_US); + } + + *val = rpt[1] << 8 | rpt[2]; + ret = IIO_VAL_INT; + +out_adc_conv: + /* Only keep ADC enable */ + adc_enable = cpu_to_be16(MT6360_ADCEN_MASK); + regmap_raw_write(mad->regmap, MT6360_REG_PMUADCCFG, &adc_enable, sizeof(adc_enable)); + mad->last_off_timestamps[channel] = ktime_get(); + /* Config prefer channel to NO_PREFER */ + regmap_update_bits(mad->regmap, MT6360_REG_PMUADCRPT1, MT6360_PREFERCH_MASK, + MT6360_NO_PREFER << MT6360_PREFERCH_SHFT); +out_adc_lock: + mutex_unlock(&mad->adc_lock); + + return ret; +} + +static int mt6360_adc_read_scale(struct mt6360_adc_data *mad, int channel, int *val, int *val2) +{ + unsigned int regval; + int ret; + + switch (channel) { + case MT6360_CHAN_USBID: + case MT6360_CHAN_VSYS: + case MT6360_CHAN_VBAT: + case MT6360_CHAN_CHG_VDDP: + case MT6360_CHAN_VREF_TS: + case MT6360_CHAN_TS: + *val = 1250; + return IIO_VAL_INT; + case MT6360_CHAN_VBUSDIV5: + *val = 6250; + return IIO_VAL_INT; + case MT6360_CHAN_VBUSDIV2: + case MT6360_CHAN_IBUS: + case MT6360_CHAN_IBAT: + *val = 2500; + + if (channel == MT6360_CHAN_IBUS) { + /* IBUS will be affected by input current limit for the different Ron */ + /* Check whether the config is <400mA or not */ + ret = regmap_read(mad->regmap, MT6360_REG_PMUCHGCTRL3, ®val); + if (ret) + return ret; + + regval = (regval & MT6360_AICR_MASK) >> MT6360_AICR_SHFT; + if (regval < MT6360_AICR_400MA) + *val = 1900; + } + + return IIO_VAL_INT; + case MT6360_CHAN_TEMP_JC: + *val = 105; + *val2 = 100; + return IIO_VAL_FRACTIONAL; + } + + return -EINVAL; +} + +static int mt6360_adc_read_offset(struct mt6360_adc_data *mad, int channel, int *val) +{ + *val = (channel == MT6360_CHAN_TEMP_JC) ? -80 : 0; + return IIO_VAL_INT; +} + +static int mt6360_adc_read_raw(struct iio_dev *iio_dev, const struct iio_chan_spec *chan, + int *val, int *val2, long mask) +{ + struct mt6360_adc_data *mad = iio_priv(iio_dev); + + switch (mask) { + case IIO_CHAN_INFO_RAW: + return mt6360_adc_read_channel(mad, chan->channel, val); + case IIO_CHAN_INFO_SCALE: + return mt6360_adc_read_scale(mad, chan->channel, val, val2); + case IIO_CHAN_INFO_OFFSET: + return mt6360_adc_read_offset(mad, chan->channel, val); + } + + return -EINVAL; +} + +static const char *mt6360_channel_labels[MT6360_CHAN_MAX] = { + "usbid", "vbusdiv5", "vbusdiv2", "vsys", "vbat", "ibus", "ibat", "chg_vddp", + "temp_jc", "vref_ts", "ts", +}; + +static int mt6360_adc_read_label(struct iio_dev *iio_dev, const struct iio_chan_spec *chan, + char *label) +{ + return snprintf(label, PAGE_SIZE, "%s\n", mt6360_channel_labels[chan->channel]); +} + +static const struct iio_info mt6360_adc_iio_info = { + .read_raw = mt6360_adc_read_raw, + .read_label = mt6360_adc_read_label, +}; + +#define MT6360_ADC_CHAN(_idx, _type) { \ + .type = _type, \ + .channel = MT6360_CHAN_##_idx, \ + .scan_index = MT6360_CHAN_##_idx, \ + .datasheet_name = #_idx, \ + .scan_type = { \ + .sign = 'u', \ + .realbits = 16, \ + .storagebits = 16, \ + .endianness = IIO_CPU, \ + }, \ + .indexed = 1, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_SCALE) | \ + BIT(IIO_CHAN_INFO_OFFSET), \ +} + +static const struct iio_chan_spec mt6360_adc_channels[] = { + MT6360_ADC_CHAN(USBID, IIO_VOLTAGE), + MT6360_ADC_CHAN(VBUSDIV5, IIO_VOLTAGE), + MT6360_ADC_CHAN(VBUSDIV2, IIO_VOLTAGE), + MT6360_ADC_CHAN(VSYS, IIO_VOLTAGE), + MT6360_ADC_CHAN(VBAT, IIO_VOLTAGE), + MT6360_ADC_CHAN(IBUS, IIO_CURRENT), + MT6360_ADC_CHAN(IBAT, IIO_CURRENT), + MT6360_ADC_CHAN(CHG_VDDP, IIO_VOLTAGE), + MT6360_ADC_CHAN(TEMP_JC, IIO_TEMP), + MT6360_ADC_CHAN(VREF_TS, IIO_VOLTAGE), + MT6360_ADC_CHAN(TS, IIO_VOLTAGE), + IIO_CHAN_SOFT_TIMESTAMP(MT6360_CHAN_MAX), +}; + +static irqreturn_t mt6360_adc_trigger_handler(int irq, void *p) +{ + struct iio_poll_func *pf = p; + struct iio_dev *indio_dev = pf->indio_dev; + struct mt6360_adc_data *mad = iio_priv(indio_dev); + struct { + u16 values[MT6360_CHAN_MAX]; + int64_t timestamp; + } data __aligned(8); + int i = 0, bit, val, ret; + + memset(&data, 0, sizeof(data)); + for_each_set_bit(bit, indio_dev->active_scan_mask, indio_dev->masklength) { + ret = mt6360_adc_read_channel(mad, bit, &val); + if (ret < 0) { + dev_warn(&indio_dev->dev, "Failed to get channel %d conversion val\n", bit); + goto out; + } + + data.values[i++] = val; + } + iio_push_to_buffers_with_timestamp(indio_dev, &data, iio_get_time_ns(indio_dev)); +out: + iio_trigger_notify_done(indio_dev->trig); + + return IRQ_HANDLED; +} + +static inline int mt6360_adc_reset(struct mt6360_adc_data *info) +{ + __be16 adc_enable; + ktime_t all_off_time; + int i, ret; + + /* Clear ADC idle wait time to 0 */ + ret = regmap_write(info->regmap, MT6360_REG_PMUADCIDLET, 0); + if (ret) + return ret; + + /* Only keep ADC enable, but keep all channels off */ + adc_enable = cpu_to_be16(MT6360_ADCEN_MASK); + ret = regmap_raw_write(info->regmap, MT6360_REG_PMUADCCFG, &adc_enable, sizeof(adc_enable)); + if (ret) + return ret; + + /* Reset all channel off time to the current one */ + all_off_time = ktime_get(); + for (i = 0; i < MT6360_CHAN_MAX; i++) + info->last_off_timestamps[i] = all_off_time; + + return 0; +} + +static int mt6360_adc_probe(struct platform_device *pdev) +{ + struct mt6360_adc_data *mad; + struct regmap *regmap; + struct iio_dev *indio_dev; + int ret; + + regmap = dev_get_regmap(pdev->dev.parent, NULL); + if (!regmap) { + dev_err(&pdev->dev, "Failed to get parent regmap\n"); + return -ENODEV; + } + + indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*mad)); + if (!indio_dev) + return -ENOMEM; + + mad = iio_priv(indio_dev); + mad->dev = &pdev->dev; + mad->regmap = regmap; + mutex_init(&mad->adc_lock); + + ret = mt6360_adc_reset(mad); + if (ret < 0) { + dev_err(&pdev->dev, "Failed to reset adc\n"); + return ret; + } + + indio_dev->name = dev_name(&pdev->dev); + indio_dev->info = &mt6360_adc_iio_info; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = mt6360_adc_channels; + indio_dev->num_channels = ARRAY_SIZE(mt6360_adc_channels); + + ret = devm_iio_triggered_buffer_setup(&pdev->dev, indio_dev, NULL, + mt6360_adc_trigger_handler, NULL); + if (ret) { + dev_err(&pdev->dev, "Failed to allocate iio trigger buffer\n"); + return ret; + } + + return devm_iio_device_register(&pdev->dev, indio_dev); +} + +static const struct of_device_id mt6360_adc_of_id[] = { + { .compatible = "mediatek,mt6360-adc", }, + {} +}; +MODULE_DEVICE_TABLE(of, mt6360_adc_of_id); + +static struct platform_driver mt6360_adc_driver = { + .driver = { + .name = "mt6360-adc", + .of_match_table = mt6360_adc_of_id, + }, + .probe = mt6360_adc_probe, +}; +module_platform_driver(mt6360_adc_driver); + +MODULE_AUTHOR("Gene Chen <gene_chen@richtek.com>"); +MODULE_DESCRIPTION("MT6360 ADC Driver"); +MODULE_LICENSE("GPL v2"); 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