diff options
| -rw-r--r-- | drivers/iio/adc/at91-sama5d2_adc.c | 256 |
1 files changed, 249 insertions, 7 deletions
diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c index 1a72e304fc3a..0a7b1680f158 100644 --- a/drivers/iio/adc/at91-sama5d2_adc.c +++ b/drivers/iio/adc/at91-sama5d2_adc.c @@ -19,6 +19,7 @@ #include <linux/of_device.h> #include <linux/platform_device.h> #include <linux/sched.h> +#include <linux/units.h> #include <linux/wait.h> #include <linux/iio/iio.h> #include <linux/iio/sysfs.h> @@ -26,9 +27,12 @@ #include <linux/iio/trigger.h> #include <linux/iio/trigger_consumer.h> #include <linux/iio/triggered_buffer.h> +#include <linux/nvmem-consumer.h> #include <linux/pinctrl/consumer.h> #include <linux/regulator/consumer.h> +#include <dt-bindings/iio/adc/at91-sama5d2_adc.h> + struct at91_adc_reg_layout { /* Control Register */ u16 CR; @@ -73,10 +77,13 @@ struct at91_adc_reg_layout { /* Startup Time */ #define AT91_SAMA5D2_MR_STARTUP(v) ((v) << 16) #define AT91_SAMA5D2_MR_STARTUP_MASK GENMASK(19, 16) +/* Minimum startup time for temperature sensor */ +#define AT91_SAMA5D2_MR_STARTUP_TS_MIN (50) /* Analog Change */ #define AT91_SAMA5D2_MR_ANACH BIT(23) /* Tracking Time */ #define AT91_SAMA5D2_MR_TRACKTIM(v) ((v) << 24) +#define AT91_SAMA5D2_MR_TRACKTIM_TS 6 #define AT91_SAMA5D2_MR_TRACKTIM_MAX 0xf /* Transfer Time */ #define AT91_SAMA5D2_MR_TRANSFER(v) ((v) << 28) @@ -149,6 +156,9 @@ struct at91_adc_reg_layout { #define AT91_SAMA5D2_TRACKX_MASK GENMASK(23, 22) #define AT91_SAMA5D2_TRACKX(x) (((x) << 22) & \ AT91_SAMA5D2_TRACKX_MASK) +/* TRACKX for temperature sensor. */ +#define AT91_SAMA5D2_TRACKX_TS (1) + /* Extended Mode Register - Averaging on single trigger event */ #define AT91_SAMA5D2_EMR_ASTE(V) ((V) << 20) @@ -164,6 +174,8 @@ struct at91_adc_reg_layout { u16 ACR; /* Analog Control Register - Pen detect sensitivity mask */ #define AT91_SAMA5D2_ACR_PENDETSENS_MASK GENMASK(1, 0) +/* Analog Control Register - Source last channel */ +#define AT91_SAMA5D2_ACR_SRCLCH BIT(16) /* Touchscreen Mode Register */ u16 TSMR; @@ -231,6 +243,10 @@ struct at91_adc_reg_layout { u16 WPSR; /* Version Register */ u16 VERSION; +/* Temperature Sensor Mode Register */ + u16 TEMPMR; +/* Temperature Sensor Mode - Temperature sensor on */ +#define AT91_SAMA5D2_TEMPMR_TEMPON BIT(0) }; static const struct at91_adc_reg_layout sama5d2_layout = { @@ -285,6 +301,7 @@ static const struct at91_adc_reg_layout sama7g5_layout = { .EOC_IDR = 0x38, .EOC_IMR = 0x3c, .EOC_ISR = 0x40, + .TEMPMR = 0x44, .OVER = 0x4c, .EMR = 0x50, .CWR = 0x54, @@ -391,6 +408,21 @@ static const struct at91_adc_reg_layout sama7g5_layout = { .datasheet_name = name, \ } +#define AT91_SAMA5D2_CHAN_TEMP(num, name, addr) \ + { \ + .type = IIO_TEMP, \ + .channel = num, \ + .address = addr, \ + .scan_index = num, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \ + .info_mask_shared_by_all = \ + BIT(IIO_CHAN_INFO_PROCESSED) | \ + BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \ + .info_mask_shared_by_all_available = \ + BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \ + .datasheet_name = name, \ + } + #define at91_adc_readl(st, reg) \ readl_relaxed((st)->base + (st)->soc_info.platform->layout->reg) #define at91_adc_read_chan(st, reg) \ @@ -415,6 +447,8 @@ static const struct at91_adc_reg_layout sama7g5_layout = { * @oversampling_avail: available oversampling values * @oversampling_avail_no: number of available oversampling values * @chan_realbits: realbits for registered channels + * @temp_chan: temperature channel index + * @temp_sensor: temperature sensor supported */ struct at91_adc_platform { const struct at91_adc_reg_layout *layout; @@ -430,20 +464,54 @@ struct at91_adc_platform { unsigned int oversampling_avail[5]; unsigned int oversampling_avail_no; unsigned int chan_realbits; + unsigned int temp_chan; + bool temp_sensor; }; /** + * struct at91_adc_temp_sensor_clb - at91-sama5d2 temperature sensor + * calibration data structure + * @p1: P1 calibration temperature + * @p4: P4 calibration voltage + * @p6: P6 calibration voltage + */ +struct at91_adc_temp_sensor_clb { + u32 p1; + u32 p4; + u32 p6; +}; + +/** + * enum at91_adc_ts_clb_idx - calibration indexes in NVMEM buffer + * @AT91_ADC_TS_CLB_IDX_P1: index for P1 + * @AT91_ADC_TS_CLB_IDX_P4: index for P4 + * @AT91_ADC_TS_CLB_IDX_P6: index for P6 + * @AT91_ADC_TS_CLB_IDX_MAX: max index for temperature calibration packet in OTP + */ +enum at91_adc_ts_clb_idx { + AT91_ADC_TS_CLB_IDX_P1 = 2, + AT91_ADC_TS_CLB_IDX_P4 = 5, + AT91_ADC_TS_CLB_IDX_P6 = 7, + AT91_ADC_TS_CLB_IDX_MAX = 19, +}; + +/* Temperature sensor calibration - Vtemp voltage sensitivity to temperature. */ +#define AT91_ADC_TS_VTEMP_DT (2080U) + +/** * struct at91_adc_soc_info - at91-sama5d2 soc information struct * @startup_time: device startup time * @min_sample_rate: minimum sample rate in Hz * @max_sample_rate: maximum sample rate in Hz * @platform: pointer to the platform structure + * @temp_sensor_clb: temperature sensor calibration data structure */ struct at91_adc_soc_info { unsigned startup_time; unsigned min_sample_rate; unsigned max_sample_rate; const struct at91_adc_platform *platform; + struct at91_adc_temp_sensor_clb temp_sensor_clb; }; struct at91_adc_trigger { @@ -491,6 +559,18 @@ struct at91_adc_touch { struct work_struct workq; }; +/** + * struct at91_adc_temp - at91-sama5d2 temperature information structure + * @sample_period_val: sample period value + * @saved_sample_rate: saved sample rate + * @saved_oversampling: saved oversampling + */ +struct at91_adc_temp { + u16 sample_period_val; + u16 saved_sample_rate; + u16 saved_oversampling; +}; + /* * Buffer size requirements: * No channels * bytes_per_channel(2) + timestamp bytes (8) @@ -518,6 +598,7 @@ struct at91_adc_state { wait_queue_head_t wq_data_available; struct at91_adc_dma dma_st; struct at91_adc_touch touch_st; + struct at91_adc_temp temp_st; struct iio_dev *indio_dev; /* Ensure naturally aligned timestamp */ u16 buffer[AT91_BUFFER_MAX_HWORDS] __aligned(8); @@ -607,6 +688,7 @@ static const struct iio_chan_spec at91_sama7g5_adc_channels[] = { AT91_SAMA5D2_CHAN_DIFF(22, 12, 13, 0x90), AT91_SAMA5D2_CHAN_DIFF(23, 14, 15, 0x98), IIO_CHAN_SOFT_TIMESTAMP(24), + AT91_SAMA5D2_CHAN_TEMP(AT91_SAMA7G5_ADC_TEMP_CHANNEL, "temp", 0xdc), }; static const struct at91_adc_platform sama5d2_platform = { @@ -639,10 +721,13 @@ static const struct at91_adc_platform sama7g5_platform = { .adc_channels = &at91_sama7g5_adc_channels, #define AT91_SAMA7G5_SINGLE_CHAN_CNT 16 #define AT91_SAMA7G5_DIFF_CHAN_CNT 8 +#define AT91_SAMA7G5_TEMP_CHAN_CNT 1 .nr_channels = AT91_SAMA7G5_SINGLE_CHAN_CNT + - AT91_SAMA7G5_DIFF_CHAN_CNT, + AT91_SAMA7G5_DIFF_CHAN_CNT + + AT91_SAMA7G5_TEMP_CHAN_CNT, #define AT91_SAMA7G5_MAX_CHAN_IDX (AT91_SAMA7G5_SINGLE_CHAN_CNT + \ - AT91_SAMA7G5_DIFF_CHAN_CNT) + AT91_SAMA7G5_DIFF_CHAN_CNT + \ + AT91_SAMA7G5_TEMP_CHAN_CNT) .max_channels = ARRAY_SIZE(at91_sama7g5_adc_channels), .max_index = AT91_SAMA7G5_MAX_CHAN_IDX, #define AT91_SAMA7G5_HW_TRIG_CNT 3 @@ -651,6 +736,8 @@ static const struct at91_adc_platform sama7g5_platform = { .oversampling_avail = { 1, 4, 16, 64, 256, }, .oversampling_avail_no = 5, .chan_realbits = 16, + .temp_sensor = true, + .temp_chan = AT91_SAMA7G5_ADC_TEMP_CHANNEL, }; static int at91_adc_chan_xlate(struct iio_dev *indio_dev, int chan) @@ -1193,7 +1280,8 @@ static int at91_adc_buffer_prepare(struct iio_dev *indio_dev) continue; /* these channel types cannot be handled by this trigger */ if (chan->type == IIO_POSITIONRELATIVE || - chan->type == IIO_PRESSURE) + chan->type == IIO_PRESSURE || + chan->type == IIO_TEMP) continue; at91_adc_cor(st, chan); @@ -1235,7 +1323,8 @@ static int at91_adc_buffer_postdisable(struct iio_dev *indio_dev) continue; /* these channel types are virtual, no need to do anything */ if (chan->type == IIO_POSITIONRELATIVE || - chan->type == IIO_PRESSURE) + chan->type == IIO_PRESSURE || + chan->type == IIO_TEMP) continue; at91_adc_writel(st, CHDR, BIT(chan->channel)); @@ -1613,12 +1702,19 @@ static int at91_adc_read_info_raw(struct iio_dev *indio_dev, return ret; } - /* in this case we have a voltage channel */ + /* in this case we have a voltage or temperature channel */ st->chan = chan; at91_adc_cor(st, chan); at91_adc_writel(st, CHER, BIT(chan->channel)); + /* + * TEMPMR.TEMPON needs to update after CHER otherwise if none + * of the channels are enabled and TEMPMR.TEMPON = 1 will + * trigger DRDY interruption while preparing for temperature read. + */ + if (chan->type == IIO_TEMP) + at91_adc_writel(st, TEMPMR, AT91_SAMA5D2_TEMPMR_TEMPON); at91_adc_eoc_ena(st, chan->channel); at91_adc_writel(st, CR, AT91_SAMA5D2_CR_START); @@ -1638,6 +1734,8 @@ static int at91_adc_read_info_raw(struct iio_dev *indio_dev, } at91_adc_eoc_dis(st, st->chan->channel); + if (chan->type == IIO_TEMP) + at91_adc_writel(st, TEMPMR, 0U); at91_adc_writel(st, CHDR, BIT(chan->channel)); /* Needed to ACK the DRDY interruption */ @@ -1665,6 +1763,89 @@ static int at91_adc_read_info_locked(struct iio_dev *indio_dev, return ret; } +static void at91_adc_temp_sensor_configure(struct at91_adc_state *st, + bool start) +{ + u32 sample_rate, oversampling_ratio; + u32 startup_time, tracktim, trackx; + + if (start) { + /* + * Configure the sensor for best accuracy: 10MHz frequency, + * oversampling rate of 256, tracktim=0xf and trackx=1. + */ + sample_rate = 10 * MEGA; + oversampling_ratio = 256; + startup_time = AT91_SAMA5D2_MR_STARTUP_TS_MIN; + tracktim = AT91_SAMA5D2_MR_TRACKTIM_TS; + trackx = AT91_SAMA5D2_TRACKX_TS; + + st->temp_st.saved_sample_rate = st->current_sample_rate; + st->temp_st.saved_oversampling = st->oversampling_ratio; + } else { + /* Go back to previous settings. */ + sample_rate = st->temp_st.saved_sample_rate; + oversampling_ratio = st->temp_st.saved_oversampling; + startup_time = st->soc_info.startup_time; + tracktim = 0; + trackx = 0; + } + + at91_adc_setup_samp_freq(st->indio_dev, sample_rate, startup_time, + tracktim); + at91_adc_config_emr(st, oversampling_ratio, trackx); +} + +static int at91_adc_read_temp(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int *val) +{ + struct at91_adc_state *st = iio_priv(indio_dev); + struct at91_adc_temp_sensor_clb *clb = &st->soc_info.temp_sensor_clb; + u64 div1, div2; + u32 tmp; + int ret, vbg, vtemp; + + ret = iio_device_claim_direct_mode(indio_dev); + if (ret) + return ret; + mutex_lock(&st->lock); + + at91_adc_temp_sensor_configure(st, true); + + /* Read VBG. */ + tmp = at91_adc_readl(st, ACR); + tmp |= AT91_SAMA5D2_ACR_SRCLCH; + at91_adc_writel(st, ACR, tmp); + ret = at91_adc_read_info_raw(indio_dev, chan, &vbg); + if (ret < 0) + goto restore_config; + + /* Read VTEMP. */ + tmp &= ~AT91_SAMA5D2_ACR_SRCLCH; + at91_adc_writel(st, ACR, tmp); + ret = at91_adc_read_info_raw(indio_dev, chan, &vtemp); + +restore_config: + /* Revert previous settings. */ + at91_adc_temp_sensor_configure(st, false); + mutex_unlock(&st->lock); + iio_device_release_direct_mode(indio_dev); + if (ret < 0) + return ret; + + /* + * Temp[milli] = p1[milli] + (vtemp * clb->p6 - clb->p4 * vbg)/ + * (vbg * AT91_ADC_TS_VTEMP_DT) + */ + div1 = DIV_ROUND_CLOSEST_ULL(((u64)vtemp * clb->p6), vbg); + div1 = DIV_ROUND_CLOSEST_ULL((div1 * 1000), AT91_ADC_TS_VTEMP_DT); + div2 = DIV_ROUND_CLOSEST_ULL((u64)clb->p4, AT91_ADC_TS_VTEMP_DT); + div2 *= 1000; + *val = clb->p1 + (int)div1 - (int)div2; + + return ret; +} + static int at91_adc_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) @@ -1682,6 +1863,11 @@ static int at91_adc_read_raw(struct iio_dev *indio_dev, *val2 = chan->scan_type.realbits; return IIO_VAL_FRACTIONAL_LOG2; + case IIO_CHAN_INFO_PROCESSED: + if (chan->type != IIO_TEMP) + return -EINVAL; + return at91_adc_read_temp(indio_dev, chan, val); + case IIO_CHAN_INFO_SAMP_FREQ: *val = at91_adc_get_sample_freq(st); return IIO_VAL_INT; @@ -1997,12 +2183,61 @@ static int at91_adc_buffer_and_trigger_init(struct device *dev, return 0; } +static int at91_adc_temp_sensor_init(struct at91_adc_state *st, + struct device *dev) +{ + struct at91_adc_temp_sensor_clb *clb = &st->soc_info.temp_sensor_clb; + struct nvmem_cell *temp_calib; + u32 *buf; + size_t len; + int ret = 0; + + if (!st->soc_info.platform->temp_sensor) + return 0; + + /* Get the calibration data from NVMEM. */ + temp_calib = devm_nvmem_cell_get(dev, "temperature_calib"); + if (IS_ERR(temp_calib)) { + ret = PTR_ERR(temp_calib); + if (ret != -ENOENT) + dev_err(dev, "Failed to get temperature_calib cell!\n"); + return ret; + } + + buf = nvmem_cell_read(temp_calib, &len); + if (IS_ERR(buf)) { + dev_err(dev, "Failed to read calibration data!\n"); + return PTR_ERR(buf); + } + if (len < AT91_ADC_TS_CLB_IDX_MAX * 4) { + dev_err(dev, "Invalid calibration data!\n"); + ret = -EINVAL; + goto free_buf; + } + + /* Store calibration data for later use. */ + clb->p1 = buf[AT91_ADC_TS_CLB_IDX_P1]; + clb->p4 = buf[AT91_ADC_TS_CLB_IDX_P4]; + clb->p6 = buf[AT91_ADC_TS_CLB_IDX_P6]; + + /* + * We prepare here the conversion to milli and also add constant + * factor (5 degrees Celsius) to p1 here to avoid doing it on + * hotpath. + */ + clb->p1 = clb->p1 * 1000 + 5000; + +free_buf: + kfree(buf); + return ret; +} + static int at91_adc_probe(struct platform_device *pdev) { struct iio_dev *indio_dev; struct at91_adc_state *st; struct resource *res; - int ret, i; + int ret, i, num_channels; u32 edge_type = IRQ_TYPE_NONE; indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*st)); @@ -2014,11 +2249,18 @@ static int at91_adc_probe(struct platform_device *pdev) st->soc_info.platform = of_device_get_match_data(&pdev->dev); + ret = at91_adc_temp_sensor_init(st, &pdev->dev); + /* Don't register temperature channel if initialization failed. */ + if (ret) + num_channels = st->soc_info.platform->max_channels - 1; + else + num_channels = st->soc_info.platform->max_channels; + indio_dev->name = dev_name(&pdev->dev); indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE; indio_dev->info = &at91_adc_info; indio_dev->channels = *st->soc_info.platform->adc_channels; - indio_dev->num_channels = st->soc_info.platform->max_channels; + indio_dev->num_channels = num_channels; bitmap_set(&st->touch_st.channels_bitmask, st->soc_info.platform->touch_chan_x, 1); |