diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/iio/adc/palmas_gpadc.c | 443 |
1 files changed, 419 insertions, 24 deletions
diff --git a/drivers/iio/adc/palmas_gpadc.c b/drivers/iio/adc/palmas_gpadc.c index da4908608a27..071795c8de1d 100644 --- a/drivers/iio/adc/palmas_gpadc.c +++ b/drivers/iio/adc/palmas_gpadc.c @@ -20,6 +20,7 @@ #include <linux/completion.h> #include <linux/of.h> #include <linux/of_device.h> +#include <linux/iio/events.h> #include <linux/iio/iio.h> #include <linux/iio/machine.h> #include <linux/iio/driver.h> @@ -79,10 +80,14 @@ static struct palmas_gpadc_info palmas_gpadc_info[] = { struct palmas_adc_event { bool enabled; int channel; - int raw_thresh; enum iio_event_direction direction; }; +struct palmas_gpadc_thresholds { + int high; + int low; +}; + /* * struct palmas_gpadc - the palmas_gpadc structure * @ch0_current: channel 0 current source setting @@ -120,10 +125,31 @@ struct palmas_gpadc { struct completion conv_completion; struct palmas_adc_event event0; struct palmas_adc_event event1; + struct palmas_gpadc_thresholds thresholds[PALMAS_ADC_CH_MAX]; int auto_conversion_period; struct mutex lock; }; +static struct palmas_adc_event *palmas_gpadc_get_event(struct palmas_gpadc *adc, + int adc_chan, + enum iio_event_direction dir) +{ + if (adc_chan == adc->event0.channel && dir == adc->event0.direction) + return &adc->event0; + + if (adc_chan == adc->event1.channel && dir == adc->event1.direction) + return &adc->event1; + + return NULL; +} + +static bool palmas_gpadc_channel_is_freerunning(struct palmas_gpadc *adc, + int adc_chan) +{ + return palmas_gpadc_get_event(adc, adc_chan, IIO_EV_DIR_RISING) || + palmas_gpadc_get_event(adc, adc_chan, IIO_EV_DIR_FALLING); +} + /* * GPADC lock issue in AUTO mode. * Impact: In AUTO mode, GPADC conversion can be locked after disabling AUTO @@ -193,11 +219,24 @@ static irqreturn_t palmas_gpadc_irq(int irq, void *data) static irqreturn_t palmas_gpadc_irq_auto(int irq, void *data) { - struct palmas_gpadc *adc = data; + struct iio_dev *indio_dev = data; + struct palmas_gpadc *adc = iio_priv(indio_dev); + struct palmas_adc_event *ev; dev_dbg(adc->dev, "Threshold interrupt %d occurs\n", irq); palmas_disable_auto_conversion(adc); + ev = (irq == adc->irq_auto_0) ? &adc->event0 : &adc->event1; + if (ev->channel != -1) { + enum iio_event_direction dir; + u64 code; + + dir = ev->direction; + code = IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE, ev->channel, + IIO_EV_TYPE_THRESH, dir); + iio_push_event(indio_dev, code, iio_get_time_ns(indio_dev)); + } + return IRQ_HANDLED; } @@ -285,6 +324,9 @@ static int palmas_gpadc_read_prepare(struct palmas_gpadc *adc, int adc_chan) { int ret; + if (palmas_gpadc_channel_is_freerunning(adc, adc_chan)) + return 0; /* ADC already running */ + ret = palmas_gpadc_enable(adc, adc_chan, true); if (ret < 0) return ret; @@ -344,28 +386,43 @@ static int palmas_gpadc_start_conversion(struct palmas_gpadc *adc, int adc_chan) unsigned int val; int ret; - init_completion(&adc->conv_completion); - ret = palmas_update_bits(adc->palmas, PALMAS_GPADC_BASE, - PALMAS_GPADC_SW_SELECT, - PALMAS_GPADC_SW_SELECT_SW_START_CONV0, - PALMAS_GPADC_SW_SELECT_SW_START_CONV0); - if (ret < 0) { - dev_err(adc->dev, "SELECT_SW_START write failed: %d\n", ret); - return ret; - } + if (palmas_gpadc_channel_is_freerunning(adc, adc_chan)) { + int event = (adc_chan == adc->event0.channel) ? 0 : 1; + unsigned int reg = (event == 0) ? + PALMAS_GPADC_AUTO_CONV0_LSB : + PALMAS_GPADC_AUTO_CONV1_LSB; - ret = wait_for_completion_timeout(&adc->conv_completion, - PALMAS_ADC_CONVERSION_TIMEOUT); - if (ret == 0) { - dev_err(adc->dev, "conversion not completed\n"); - return -ETIMEDOUT; - } + ret = palmas_bulk_read(adc->palmas, PALMAS_GPADC_BASE, + reg, &val, 2); + if (ret < 0) { + dev_err(adc->dev, "AUTO_CONV%x_LSB read failed: %d\n", + event, ret); + return ret; + } + } else { + init_completion(&adc->conv_completion); + ret = palmas_update_bits(adc->palmas, PALMAS_GPADC_BASE, + PALMAS_GPADC_SW_SELECT, + PALMAS_GPADC_SW_SELECT_SW_START_CONV0, + PALMAS_GPADC_SW_SELECT_SW_START_CONV0); + if (ret < 0) { + dev_err(adc->dev, "SELECT_SW_START write failed: %d\n", ret); + return ret; + } - ret = palmas_bulk_read(adc->palmas, PALMAS_GPADC_BASE, - PALMAS_GPADC_SW_CONV0_LSB, &val, 2); - if (ret < 0) { - dev_err(adc->dev, "SW_CONV0_LSB read failed: %d\n", ret); - return ret; + ret = wait_for_completion_timeout(&adc->conv_completion, + PALMAS_ADC_CONVERSION_TIMEOUT); + if (ret == 0) { + dev_err(adc->dev, "conversion not completed\n"); + return -ETIMEDOUT; + } + + ret = palmas_bulk_read(adc->palmas, PALMAS_GPADC_BASE, + PALMAS_GPADC_SW_CONV0_LSB, &val, 2); + if (ret < 0) { + dev_err(adc->dev, "SW_CONV0_LSB read failed: %d\n", ret); + return ret; + } } ret = val & 0xFFF; @@ -391,6 +448,98 @@ static int palmas_gpadc_get_calibrated_code(struct palmas_gpadc *adc, return val; } +/* + * The high and low threshold values are calculated based on the advice given + * in TI Application Report SLIA087A, "Guide to Using the GPADC in PS65903x, + * TPS65917-Q1, TPS65919-Q1, and TPS65916 Devices". This document recommend + * taking ADC tolerances into account and is based on the device integral non- + * linearity (INL), offset error and gain error: + * + * raw high threshold = (ideal threshold + INL) * gain error + offset error + * + * The gain error include both gain error, as specified in the datasheet, and + * the gain error drift. These paramenters vary depending on device and whether + * the the channel is calibrated (trimmed) or not. + */ +static int palmas_gpadc_threshold_with_tolerance(int val, const int INL, + const int gain_error, + const int offset_error) +{ + val = ((val + INL) * (1000 + gain_error)) / 1000 + offset_error; + + return clamp(val, 0, 0xFFF); +} + +/* + * The values below are taken from the datasheet of TWL6035, TWL6037. + * todo: get max INL, gain error, and offset error from OF. + */ +static int palmas_gpadc_get_high_threshold_raw(struct palmas_gpadc *adc, + struct palmas_adc_event *ev) +{ + const int adc_chan = ev->channel; + int val = adc->thresholds[adc_chan].high; + /* integral nonlinearity, measured in LSB */ + const int max_INL = 2; + /* measured in LSB */ + int max_offset_error; + /* 0.2% when calibrated */ + int max_gain_error = 2; + + val = (val * 1000) / adc->adc_info[adc_chan].gain; + + if (adc->adc_info[adc_chan].is_uncalibrated) { + /* 2% worse */ + max_gain_error += 20; + max_offset_error = 36; + } else { + val = (val * adc->adc_info[adc_chan].gain_error + + adc->adc_info[adc_chan].offset) / + 1000; + max_offset_error = 2; + } + + return palmas_gpadc_threshold_with_tolerance(val, + max_INL, + max_gain_error, + max_offset_error); +} + +/* + * The values below are taken from the datasheet of TWL6035, TWL6037. + * todo: get min INL, gain error, and offset error from OF. + */ +static int palmas_gpadc_get_low_threshold_raw(struct palmas_gpadc *adc, + struct palmas_adc_event *ev) +{ + const int adc_chan = ev->channel; + int val = adc->thresholds[adc_chan].low; + /* integral nonlinearity, measured in LSB */ + const int min_INL = -2; + /* measured in LSB */ + int min_offset_error; + /* -0.6% when calibrated */ + int min_gain_error = -6; + + val = (val * 1000) / adc->adc_info[adc_chan].gain; + + if (adc->adc_info[adc_chan].is_uncalibrated) { + /* 2% worse */ + min_gain_error -= 20; + min_offset_error = -36; + } else { + val = (val * adc->adc_info[adc_chan].gain_error - + adc->adc_info[adc_chan].offset) / + 1000; + min_offset_error = -2; + } + + return palmas_gpadc_threshold_with_tolerance(val, + min_INL, + min_gain_error, + min_offset_error); +} + static int palmas_gpadc_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { @@ -437,8 +586,217 @@ out: return ret; } +static int palmas_gpadc_read_event_config(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + enum iio_event_type type, + enum iio_event_direction dir) +{ + struct palmas_gpadc *adc = iio_priv(indio_dev); + int adc_chan = chan->channel; + int ret = 0; + + if (adc_chan > PALMAS_ADC_CH_MAX || type != IIO_EV_TYPE_THRESH) + return -EINVAL; + + mutex_lock(&adc->lock); + + if (palmas_gpadc_get_event(adc, adc_chan, dir)) + ret = 1; + + mutex_unlock(&adc->lock); + + return ret; +} + +static int palmas_adc_configure_events(struct palmas_gpadc *adc); +static int palmas_adc_reset_events(struct palmas_gpadc *adc); + +static int palmas_gpadc_reconfigure_event_channels(struct palmas_gpadc *adc) +{ + return (adc->event0.enabled || adc->event1.enabled) ? + palmas_adc_configure_events(adc) : + palmas_adc_reset_events(adc); +} + +static int palmas_gpadc_enable_event_config(struct palmas_gpadc *adc, + const struct iio_chan_spec *chan, + enum iio_event_direction dir) +{ + struct palmas_adc_event *ev; + int adc_chan = chan->channel; + + if (palmas_gpadc_get_event(adc, adc_chan, dir)) + /* already enabled */ + return 0; + + if (adc->event0.channel == -1) { + ev = &adc->event0; + } else if (adc->event1.channel == -1) { + /* event0 has to be the lowest channel */ + if (adc_chan < adc->event0.channel) { + adc->event1 = adc->event0; + ev = &adc->event0; + } else { + ev = &adc->event1; + } + } else { /* both AUTO channels already in use */ + dev_warn(adc->dev, "event0 - %d, event1 - %d\n", + adc->event0.channel, adc->event1.channel); + return -EBUSY; + } + + ev->enabled = true; + ev->channel = adc_chan; + ev->direction = dir; + + return palmas_gpadc_reconfigure_event_channels(adc); +} + +static int palmas_gpadc_disable_event_config(struct palmas_gpadc *adc, + const struct iio_chan_spec *chan, + enum iio_event_direction dir) +{ + int adc_chan = chan->channel; + struct palmas_adc_event *ev = palmas_gpadc_get_event(adc, adc_chan, dir); + + if (!ev) + return 0; + + if (ev == &adc->event0) { + adc->event0 = adc->event1; + ev = &adc->event1; + } + + ev->enabled = false; + ev->channel = -1; + ev->direction = IIO_EV_DIR_NONE; + + return palmas_gpadc_reconfigure_event_channels(adc); +} + +static int palmas_gpadc_write_event_config(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + enum iio_event_type type, + enum iio_event_direction dir, + int state) +{ + struct palmas_gpadc *adc = iio_priv(indio_dev); + int adc_chan = chan->channel; + int ret; + + if (adc_chan > PALMAS_ADC_CH_MAX || type != IIO_EV_TYPE_THRESH) + return -EINVAL; + + mutex_lock(&adc->lock); + + if (state) + ret = palmas_gpadc_enable_event_config(adc, chan, dir); + else + ret = palmas_gpadc_disable_event_config(adc, chan, dir); + + mutex_unlock(&adc->lock); + + return ret; +} + +static int palmas_gpadc_read_event_value(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + enum iio_event_type type, + enum iio_event_direction dir, + enum iio_event_info info, + int *val, int *val2) +{ + struct palmas_gpadc *adc = iio_priv(indio_dev); + int adc_chan = chan->channel; + int ret; + + if (adc_chan > PALMAS_ADC_CH_MAX || type != IIO_EV_TYPE_THRESH) + return -EINVAL; + + mutex_lock(&adc->lock); + + switch (info) { + case IIO_EV_INFO_VALUE: + *val = (dir == IIO_EV_DIR_RISING) ? + adc->thresholds[adc_chan].high : + adc->thresholds[adc_chan].low; + ret = IIO_VAL_INT; + break; + default: + ret = -EINVAL; + break; + } + + mutex_unlock(&adc->lock); + + return ret; +} + +static int palmas_gpadc_write_event_value(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + enum iio_event_type type, + enum iio_event_direction dir, + enum iio_event_info info, + int val, int val2) +{ + struct palmas_gpadc *adc = iio_priv(indio_dev); + int adc_chan = chan->channel; + int old; + int ret; + + if (adc_chan > PALMAS_ADC_CH_MAX || type != IIO_EV_TYPE_THRESH) + return -EINVAL; + + mutex_lock(&adc->lock); + switch (info) { + case IIO_EV_INFO_VALUE: + if (val < 0 || val > 0xFFF) { + ret = -EINVAL; + goto out_unlock; + } + if (dir == IIO_EV_DIR_RISING) { + old = adc->thresholds[adc_chan].high; + adc->thresholds[adc_chan].high = val; + } else { + old = adc->thresholds[adc_chan].low; + adc->thresholds[adc_chan].low = val; + } + ret = 0; + break; + default: + ret = -EINVAL; + goto out_unlock; + } + + if (val != old && palmas_gpadc_get_event(adc, adc_chan, dir)) + ret = palmas_gpadc_reconfigure_event_channels(adc); + +out_unlock: + mutex_unlock(&adc->lock); + + return ret; +} + static const struct iio_info palmas_gpadc_iio_info = { .read_raw = palmas_gpadc_read_raw, + .read_event_config = palmas_gpadc_read_event_config, + .write_event_config = palmas_gpadc_write_event_config, + .read_event_value = palmas_gpadc_read_event_value, + .write_event_value = palmas_gpadc_write_event_value, +}; + +static const struct iio_event_spec palmas_gpadc_events[] = { + { + .type = IIO_EV_TYPE_THRESH, + .dir = IIO_EV_DIR_RISING, + .mask_separate = BIT(IIO_EV_INFO_VALUE) | + BIT(IIO_EV_INFO_ENABLE), + }, { + .type = IIO_EV_TYPE_THRESH, + .dir = IIO_EV_DIR_FALLING, + .mask_separate = BIT(IIO_EV_INFO_VALUE) | + BIT(IIO_EV_INFO_ENABLE), + }, }; #define PALMAS_ADC_CHAN_IIO(chan, _type, chan_info) \ @@ -449,6 +807,8 @@ static const struct iio_info palmas_gpadc_iio_info = { BIT(chan_info), \ .indexed = 1, \ .channel = PALMAS_ADC_CH_##chan, \ + .event_spec = palmas_gpadc_events, \ + .num_event_specs = ARRAY_SIZE(palmas_gpadc_events) \ } static const struct iio_chan_spec palmas_gpadc_iio_channel[] = { @@ -555,6 +915,39 @@ static int palmas_gpadc_probe(struct platform_device *pdev) return dev_err_probe(adc->dev, ret, "request irq %d failed\n", adc->irq); + adc->irq_auto_0 = platform_get_irq(pdev, 1); + if (adc->irq_auto_0 < 0) + return dev_err_probe(adc->dev, adc->irq_auto_0, + "get auto0 irq failed\n"); + + ret = devm_request_threaded_irq(&pdev->dev, adc->irq_auto_0, NULL, + palmas_gpadc_irq_auto, IRQF_ONESHOT, + "palmas-adc-auto-0", indio_dev); + if (ret < 0) + return dev_err_probe(adc->dev, ret, + "request auto0 irq %d failed\n", + adc->irq_auto_0); + + adc->irq_auto_1 = platform_get_irq(pdev, 2); + if (adc->irq_auto_1 < 0) + return dev_err_probe(adc->dev, adc->irq_auto_1, + "get auto1 irq failed\n"); + + ret = devm_request_threaded_irq(&pdev->dev, adc->irq_auto_1, NULL, + palmas_gpadc_irq_auto, IRQF_ONESHOT, + "palmas-adc-auto-1", indio_dev); + if (ret < 0) + return dev_err_probe(adc->dev, ret, + "request auto1 irq %d failed\n", + adc->irq_auto_1); + + adc->event0.enabled = false; + adc->event0.channel = -1; + adc->event0.direction = IIO_EV_DIR_NONE; + adc->event1.enabled = false; + adc->event1.channel = -1; + adc->event1.direction = IIO_EV_DIR_NONE; + /* set the current source 0 (value 0/5/15/20 uA => 0..3) */ if (gpadc_pdata->ch0_current <= 1) adc->ch0_current = PALMAS_ADC_CH0_CURRENT_SRC_0; @@ -632,13 +1025,14 @@ static int palmas_adc_configure_events(struct palmas_gpadc *adc) int polarity; ch0 = ev->channel; - thres = ev->raw_thresh; conv |= PALMAS_GPADC_AUTO_CTRL_AUTO_CONV0_EN; switch (ev->direction) { case IIO_EV_DIR_RISING: + thres = palmas_gpadc_get_high_threshold_raw(adc, ev); polarity = 0; break; case IIO_EV_DIR_FALLING: + thres = palmas_gpadc_get_low_threshold_raw(adc, ev); polarity = PALMAS_GPADC_THRES_CONV0_MSB_THRES_CONV0_POL; break; default: @@ -668,13 +1062,14 @@ static int palmas_adc_configure_events(struct palmas_gpadc *adc) int polarity; ch1 = ev->channel; - thres = ev->raw_thresh; conv |= PALMAS_GPADC_AUTO_CTRL_AUTO_CONV1_EN; switch (ev->direction) { case IIO_EV_DIR_RISING: + thres = palmas_gpadc_get_high_threshold_raw(adc, ev); polarity = 0; break; case IIO_EV_DIR_FALLING: + thres = palmas_gpadc_get_low_threshold_raw(adc, ev); polarity = PALMAS_GPADC_THRES_CONV1_MSB_THRES_CONV1_POL; break; default: |