// SPDX-License-Identifier: GPL-2.0-or-later /* * Freescale MXS LRADC ADC driver * * Copyright (c) 2012 DENX Software Engineering, GmbH. * Copyright (c) 2017 Ksenija Stanojevic * * Authors: * Marek Vasut * Ksenija Stanojevic */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * Make this runtime configurable if necessary. Currently, if the buffered mode * is enabled, the LRADC takes LRADC_DELAY_TIMER_LOOP samples of data before * triggering IRQ. The sampling happens every (LRADC_DELAY_TIMER_PER / 2000) * seconds. The result is that the samples arrive every 500mS. */ #define LRADC_DELAY_TIMER_PER 200 #define LRADC_DELAY_TIMER_LOOP 5 #define VREF_MV_BASE 1850 static const char *mx23_lradc_adc_irq_names[] = { "mxs-lradc-channel0", "mxs-lradc-channel1", "mxs-lradc-channel2", "mxs-lradc-channel3", "mxs-lradc-channel4", "mxs-lradc-channel5", }; static const char *mx28_lradc_adc_irq_names[] = { "mxs-lradc-thresh0", "mxs-lradc-thresh1", "mxs-lradc-channel0", "mxs-lradc-channel1", "mxs-lradc-channel2", "mxs-lradc-channel3", "mxs-lradc-channel4", "mxs-lradc-channel5", "mxs-lradc-button0", "mxs-lradc-button1", }; static const u32 mxs_lradc_adc_vref_mv[][LRADC_MAX_TOTAL_CHANS] = { [IMX23_LRADC] = { VREF_MV_BASE, /* CH0 */ VREF_MV_BASE, /* CH1 */ VREF_MV_BASE, /* CH2 */ VREF_MV_BASE, /* CH3 */ VREF_MV_BASE, /* CH4 */ VREF_MV_BASE, /* CH5 */ VREF_MV_BASE * 2, /* CH6 VDDIO */ VREF_MV_BASE * 4, /* CH7 VBATT */ VREF_MV_BASE, /* CH8 Temp sense 0 */ VREF_MV_BASE, /* CH9 Temp sense 1 */ VREF_MV_BASE, /* CH10 */ VREF_MV_BASE, /* CH11 */ VREF_MV_BASE, /* CH12 USB_DP */ VREF_MV_BASE, /* CH13 USB_DN */ VREF_MV_BASE, /* CH14 VBG */ VREF_MV_BASE * 4, /* CH15 VDD5V */ }, [IMX28_LRADC] = { VREF_MV_BASE, /* CH0 */ VREF_MV_BASE, /* CH1 */ VREF_MV_BASE, /* CH2 */ VREF_MV_BASE, /* CH3 */ VREF_MV_BASE, /* CH4 */ VREF_MV_BASE, /* CH5 */ VREF_MV_BASE, /* CH6 */ VREF_MV_BASE * 4, /* CH7 VBATT */ VREF_MV_BASE, /* CH8 Temp sense 0 */ VREF_MV_BASE, /* CH9 Temp sense 1 */ VREF_MV_BASE * 2, /* CH10 VDDIO */ VREF_MV_BASE, /* CH11 VTH */ VREF_MV_BASE * 2, /* CH12 VDDA */ VREF_MV_BASE, /* CH13 VDDD */ VREF_MV_BASE, /* CH14 VBG */ VREF_MV_BASE * 4, /* CH15 VDD5V */ }, }; enum mxs_lradc_divbytwo { MXS_LRADC_DIV_DISABLED = 0, MXS_LRADC_DIV_ENABLED, }; struct mxs_lradc_scale { unsigned int integer; unsigned int nano; }; struct mxs_lradc_adc { struct mxs_lradc *lradc; struct device *dev; void __iomem *base; /* Maximum of 8 channels + 8 byte ts */ u32 buffer[10] __aligned(8); struct iio_trigger *trig; struct completion completion; spinlock_t lock; const u32 *vref_mv; struct mxs_lradc_scale scale_avail[LRADC_MAX_TOTAL_CHANS][2]; unsigned long is_divided; }; /* Raw I/O operations */ static int mxs_lradc_adc_read_single(struct iio_dev *iio_dev, int chan, int *val) { struct mxs_lradc_adc *adc = iio_priv(iio_dev); struct mxs_lradc *lradc = adc->lradc; int ret; /* * See if there is no buffered operation in progress. If there is simply * bail out. This can be improved to support both buffered and raw IO at * the same time, yet the code becomes horribly complicated. Therefore I * applied KISS principle here. */ ret = iio_device_claim_direct_mode(iio_dev); if (ret) return ret; reinit_completion(&adc->completion); /* * No buffered operation in progress, map the channel and trigger it. * Virtual channel 0 is always used here as the others are always not * used if doing raw sampling. */ if (lradc->soc == IMX28_LRADC) writel(LRADC_CTRL1_LRADC_IRQ_EN(0), adc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR); writel(0x1, adc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR); /* Enable / disable the divider per requirement */ if (test_bit(chan, &adc->is_divided)) writel(1 << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET, adc->base + LRADC_CTRL2 + STMP_OFFSET_REG_SET); else writel(1 << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET, adc->base + LRADC_CTRL2 + STMP_OFFSET_REG_CLR); /* Clean the slot's previous content, then set new one. */ writel(LRADC_CTRL4_LRADCSELECT_MASK(0), adc->base + LRADC_CTRL4 + STMP_OFFSET_REG_CLR); writel(chan, adc->base + LRADC_CTRL4 + STMP_OFFSET_REG_SET); writel(0, adc->base + LRADC_CH(0)); /* Enable the IRQ and start sampling the channel. */ writel(LRADC_CTRL1_LRADC_IRQ_EN(0), adc->base + LRADC_CTRL1 + STMP_OFFSET_REG_SET); writel(BIT(0), adc->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET); /* Wait for completion on the channel, 1 second max. */ ret = wait_for_completion_killable_timeout(&adc->completion, HZ); if (!ret) ret = -ETIMEDOUT; if (ret < 0) goto err; /* Read the data. */ *val = readl(adc->base + LRADC_CH(0)) & LRADC_CH_VALUE_MASK; ret = IIO_VAL_INT; err: writel(LRADC_CTRL1_LRADC_IRQ_EN(0), adc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR); iio_device_release_direct_mode(iio_dev); return ret; } static int mxs_lradc_adc_read_temp(struct iio_dev *iio_dev, int *val) { int ret, min, max; ret = mxs_lradc_adc_read_single(iio_dev, 8, &min); if (ret != IIO_VAL_INT) return ret; ret = mxs_lradc_adc_read_single(iio_dev, 9, &max); if (ret != IIO_VAL_INT) return ret; *val = max - min; return IIO_VAL_INT; } static int mxs_lradc_adc_read_raw(struct iio_dev *iio_dev, const struct iio_chan_spec *chan, int *val, int *val2, long m) { struct mxs_lradc_adc *adc = iio_priv(iio_dev); switch (m) { case IIO_CHAN_INFO_RAW: if (chan->type == IIO_TEMP) return mxs_lradc_adc_read_temp(iio_dev, val); return mxs_lradc_adc_read_single(iio_dev, chan->channel, val); case IIO_CHAN_INFO_SCALE: if (chan->type == IIO_TEMP) { /* * From the datasheet, we have to multiply by 1.012 and * divide by 4 */ *val = 0; *val2 = 253000; return IIO_VAL_INT_PLUS_MICRO; } *val = adc->vref_mv[chan->channel]; *val2 = chan->scan_type.realbits - test_bit(chan->channel, &adc->is_divided); return IIO_VAL_FRACTIONAL_LOG2; case IIO_CHAN_INFO_OFFSET: if (chan->type == IIO_TEMP) { /* * The calculated value from the ADC is in Kelvin, we * want Celsius for hwmon so the offset is -273.15 * The offset is applied before scaling so it is * actually -213.15 * 4 / 1.012 = -1079.644268 */ *val = -1079; *val2 = 644268; return IIO_VAL_INT_PLUS_MICRO; } return -EINVAL; default: break; } return -EINVAL; } static int mxs_lradc_adc_write_raw(struct iio_dev *iio_dev, const struct iio_chan_spec *chan, int val, int val2, long m) { struct mxs_lradc_adc *adc = iio_priv(iio_dev); struct mxs_lradc_scale *scale_avail = adc->scale_avail[chan->channel]; int ret; ret = iio_device_claim_direct_mode(iio_dev); if (ret) return ret; switch (m) { case IIO_CHAN_INFO_SCALE: ret = -EINVAL; if (val == scale_avail[MXS_LRADC_DIV_DISABLED].integer && val2 == scale_avail[MXS_LRADC_DIV_DISABLED].nano) { /* divider by two disabled */ clear_bit(chan->channel, &adc->is_divided); ret = 0; } else if (val == scale_avail[MXS_LRADC_DIV_ENABLED].integer && val2 == scale_avail[MXS_LRADC_DIV_ENABLED].nano) { /* divider by two enabled */ set_bit(chan->channel, &adc->is_divided); ret = 0; } break; default: ret = -EINVAL; break; } iio_device_release_direct_mode(iio_dev); return ret; } static int mxs_lradc_adc_write_raw_get_fmt(struct iio_dev *iio_dev, const struct iio_chan_spec *chan, long m) { return IIO_VAL_INT_PLUS_NANO; } static ssize_t mxs_lradc_adc_show_scale_avail(struct device *dev, struct device_attribute *attr, char *buf) { struct iio_dev *iio = dev_to_iio_dev(dev); struct mxs_lradc_adc *adc = iio_priv(iio); struct iio_dev_attr *iio_attr = to_iio_dev_attr(attr); int i, ch, len = 0; ch = iio_attr->address; for (i = 0; i < ARRAY_SIZE(adc->scale_avail[ch]); i++) len += sprintf(buf + len, "%u.%09u ", adc->scale_avail[ch][i].integer, adc->scale_avail[ch][i].nano); len += sprintf(buf + len, "\n"); return len; } #define SHOW_SCALE_AVAILABLE_ATTR(ch)\ IIO_DEVICE_ATTR(in_voltage##ch##_scale_available, 0444,\ mxs_lradc_adc_show_scale_avail, NULL, ch) static SHOW_SCALE_AVAILABLE_ATTR(0); static SHOW_SCALE_AVAILABLE_ATTR(1); static SHOW_SCALE_AVAILABLE_ATTR(2); static SHOW_SCALE_AVAILABLE_ATTR(3); static SHOW_SCALE_AVAILABLE_ATTR(4); static SHOW_SCALE_AVAILABLE_ATTR(5); static SHOW_SCALE_AVAILABLE_ATTR(6); static SHOW_SCALE_AVAILABLE_ATTR(7); static SHOW_SCALE_AVAILABLE_ATTR(10); static SHOW_SCALE_AVAILABLE_ATTR(11); static SHOW_SCALE_AVAILABLE_ATTR(12); static SHOW_SCALE_AVAILABLE_ATTR(13); static SHOW_SCALE_AVAILABLE_ATTR(14); static SHOW_SCALE_AVAILABLE_ATTR(15); static struct attribute *mxs_lradc_adc_attributes[] = { &iio_dev_attr_in_voltage0_scale_available.dev_attr.attr, &iio_dev_attr_in_voltage1_scale_available.dev_attr.attr, &iio_dev_attr_in_voltage2_scale_available.dev_attr.attr, &iio_dev_attr_in_voltage3_scale_available.dev_attr.attr, &iio_dev_attr_in_voltage4_scale_available.dev_attr.attr, &iio_dev_attr_in_voltage5_scale_available.dev_attr.attr, &iio_dev_attr_in_voltage6_scale_available.dev_attr.attr, &iio_dev_attr_in_voltage7_scale_available.dev_attr.attr, &iio_dev_attr_in_voltage10_scale_available.dev_attr.attr, &iio_dev_attr_in_voltage11_scale_available.dev_attr.attr, &iio_dev_attr_in_voltage12_scale_available.dev_attr.attr, &iio_dev_attr_in_voltage13_scale_available.dev_attr.attr, &iio_dev_attr_in_voltage14_scale_available.dev_attr.attr, &iio_dev_attr_in_voltage15_scale_available.dev_attr.attr, NULL }; static const struct attribute_group mxs_lradc_adc_attribute_group = { .attrs = mxs_lradc_adc_attributes, }; static const struct iio_info mxs_lradc_adc_iio_info = { .read_raw = mxs_lradc_adc_read_raw, .write_raw = mxs_lradc_adc_write_raw, .write_raw_get_fmt = mxs_lradc_adc_write_raw_get_fmt, .attrs = &mxs_lradc_adc_attribute_group, }; /* IRQ Handling */ static irqreturn_t mxs_lradc_adc_handle_irq(int irq, void *data) { struct iio_dev *iio = data; struct mxs_lradc_adc *adc = iio_priv(iio); struct mxs_lradc *lradc = adc->lradc; unsigned long reg = readl(adc->base + LRADC_CTRL1); unsigned long flags; if (!(reg & mxs_lradc_irq_mask(lradc))) return IRQ_NONE; if (iio_buffer_enabled(iio)) { if (reg & lradc->buffer_vchans) { spin_lock_irqsave(&adc->lock, flags); iio_trigger_poll(iio->trig); spin_unlock_irqrestore(&adc->lock, flags); } } else if (reg & LRADC_CTRL1_LRADC_IRQ(0)) { complete(&adc->completion); } writel(reg & mxs_lradc_irq_mask(lradc), adc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR); return IRQ_HANDLED; } /* Trigger handling */ static irqreturn_t mxs_lradc_adc_trigger_handler(int irq, void *p) { struct iio_poll_func *pf = p; struct iio_dev *iio = pf->indio_dev; struct mxs_lradc_adc *adc = iio_priv(iio); const u32 chan_value = LRADC_CH_ACCUMULATE | ((LRADC_DELAY_TIMER_LOOP - 1) << LRADC_CH_NUM_SAMPLES_OFFSET); unsigned int i, j = 0; for_each_set_bit(i, iio->active_scan_mask, LRADC_MAX_TOTAL_CHANS) { adc->buffer[j] = readl(adc->base + LRADC_CH(j)); writel(chan_value, adc->base + LRADC_CH(j)); adc->buffer[j] &= LRADC_CH_VALUE_MASK; adc->buffer[j] /= LRADC_DELAY_TIMER_LOOP; j++; } iio_push_to_buffers_with_timestamp(iio, adc->buffer, pf->timestamp); iio_trigger_notify_done(iio->trig); return IRQ_HANDLED; } static int mxs_lradc_adc_configure_trigger(struct iio_trigger *trig, bool state) { struct iio_dev *iio = iio_trigger_get_drvdata(trig); struct mxs_lradc_adc *adc = iio_priv(iio); const u32 st = state ? STMP_OFFSET_REG_SET : STMP_OFFSET_REG_CLR; writel(LRADC_DELAY_KICK, adc->base + (LRADC_DELAY(0) + st)); return 0; } static const struct iio_trigger_ops mxs_lradc_adc_trigger_ops = { .set_trigger_state = &mxs_lradc_adc_configure_trigger, }; static int mxs_lradc_adc_trigger_init(struct iio_dev *iio) { int ret; struct iio_trigger *trig; struct mxs_lradc_adc *adc = iio_priv(iio); trig = devm_iio_trigger_alloc(&iio->dev, "%s-dev%i", iio->name, iio_device_id(iio)); if (!trig) return -ENOMEM; trig->dev.parent = adc->dev; iio_trigger_set_drvdata(trig, iio); trig->ops = &mxs_lradc_adc_trigger_ops; ret = iio_trigger_register(trig); if (ret) return ret; adc->trig = trig; return 0; } static void mxs_lradc_adc_trigger_remove(struct iio_dev *iio) { struct mxs_lradc_adc *adc = iio_priv(iio); iio_trigger_unregister(adc->trig); } static int mxs_lradc_adc_buffer_preenable(struct iio_dev *iio) { struct mxs_lradc_adc *adc = iio_priv(iio); struct mxs_lradc *lradc = adc->lradc; int chan, ofs = 0; unsigned long enable = 0; u32 ctrl4_set = 0; u32 ctrl4_clr = 0; u32 ctrl1_irq = 0; const u32 chan_value = LRADC_CH_ACCUMULATE | ((LRADC_DELAY_TIMER_LOOP - 1) << LRADC_CH_NUM_SAMPLES_OFFSET); if (lradc->soc == IMX28_LRADC) writel(lradc->buffer_vchans << LRADC_CTRL1_LRADC_IRQ_EN_OFFSET, adc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR); writel(lradc->buffer_vchans, adc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR); for_each_set_bit(chan, iio->active_scan_mask, LRADC_MAX_TOTAL_CHANS) { ctrl4_set |= chan << LRADC_CTRL4_LRADCSELECT_OFFSET(ofs); ctrl4_clr |= LRADC_CTRL4_LRADCSELECT_MASK(ofs); ctrl1_irq |= LRADC_CTRL1_LRADC_IRQ_EN(ofs); writel(chan_value, adc->base + LRADC_CH(ofs)); bitmap_set(&enable, ofs, 1); ofs++; } writel(LRADC_DELAY_TRIGGER_LRADCS_MASK | LRADC_DELAY_KICK, adc->base + LRADC_DELAY(0) + STMP_OFFSET_REG_CLR); writel(ctrl4_clr, adc->base + LRADC_CTRL4 + STMP_OFFSET_REG_CLR); writel(ctrl4_set, adc->base + LRADC_CTRL4 + STMP_OFFSET_REG_SET); writel(ctrl1_irq, adc->base + LRADC_CTRL1 + STMP_OFFSET_REG_SET); writel(enable << LRADC_DELAY_TRIGGER_LRADCS_OFFSET, adc->base + LRADC_DELAY(0) + STMP_OFFSET_REG_SET); return 0; } static int mxs_lradc_adc_buffer_postdisable(struct iio_dev *iio) { struct mxs_lradc_adc *adc = iio_priv(iio); struct mxs_lradc *lradc = adc->lradc; writel(LRADC_DELAY_TRIGGER_LRADCS_MASK | LRADC_DELAY_KICK, adc->base + LRADC_DELAY(0) + STMP_OFFSET_REG_CLR); writel(lradc->buffer_vchans, adc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR); if (lradc->soc == IMX28_LRADC) writel(lradc->buffer_vchans << LRADC_CTRL1_LRADC_IRQ_EN_OFFSET, adc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR); return 0; } static bool mxs_lradc_adc_validate_scan_mask(struct iio_dev *iio, const unsigned long *mask) { struct mxs_lradc_adc *adc = iio_priv(iio); struct mxs_lradc *lradc = adc->lradc; const int map_chans = bitmap_weight(mask, LRADC_MAX_TOTAL_CHANS); int rsvd_chans = 0; unsigned long rsvd_mask = 0; if (lradc->use_touchbutton) rsvd_mask |= CHAN_MASK_TOUCHBUTTON; if (lradc->touchscreen_wire == MXS_LRADC_TOUCHSCREEN_4WIRE) rsvd_mask |= CHAN_MASK_TOUCHSCREEN_4WIRE; if (lradc->touchscreen_wire == MXS_LRADC_TOUCHSCREEN_5WIRE) rsvd_mask |= CHAN_MASK_TOUCHSCREEN_5WIRE; if (lradc->use_touchbutton) rsvd_chans++; if (lradc->touchscreen_wire) rsvd_chans += 2; /* Test for attempts to map channels with special mode of operation. */ if (bitmap_intersects(mask, &rsvd_mask, LRADC_MAX_TOTAL_CHANS)) return false; /* Test for attempts to map more channels then available slots. */ if (map_chans + rsvd_chans > LRADC_MAX_MAPPED_CHANS) return false; return true; } static const struct iio_buffer_setup_ops mxs_lradc_adc_buffer_ops = { .preenable = &mxs_lradc_adc_buffer_preenable, .postdisable = &mxs_lradc_adc_buffer_postdisable, .validate_scan_mask = &mxs_lradc_adc_validate_scan_mask, }; /* Driver initialization */ #define MXS_ADC_CHAN(idx, chan_type, name) { \ .type = (chan_type), \ .indexed = 1, \ .scan_index = (idx), \ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ BIT(IIO_CHAN_INFO_SCALE), \ .channel = (idx), \ .address = (idx), \ .scan_type = { \ .sign = 'u', \ .realbits = LRADC_RESOLUTION, \ .storagebits = 32, \ }, \ .datasheet_name = (name), \ } static const struct iio_chan_spec mx23_lradc_chan_spec[] = { MXS_ADC_CHAN(0, IIO_VOLTAGE, "LRADC0"), MXS_ADC_CHAN(1, IIO_VOLTAGE, "LRADC1"), MXS_ADC_CHAN(2, IIO_VOLTAGE, "LRADC2"), MXS_ADC_CHAN(3, IIO_VOLTAGE, "LRADC3"), MXS_ADC_CHAN(4, IIO_VOLTAGE, "LRADC4"), MXS_ADC_CHAN(5, IIO_VOLTAGE, "LRADC5"), MXS_ADC_CHAN(6, IIO_VOLTAGE, "VDDIO"), MXS_ADC_CHAN(7, IIO_VOLTAGE, "VBATT"), /* Combined Temperature sensors */ { .type = IIO_TEMP, .indexed = 1, .scan_index = 8, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_SCALE), .channel = 8, .scan_type = {.sign = 'u', .realbits = 18, .storagebits = 32,}, .datasheet_name = "TEMP_DIE", }, /* Hidden channel to keep indexes */ { .type = IIO_TEMP, .indexed = 1, .scan_index = -1, .channel = 9, }, MXS_ADC_CHAN(10, IIO_VOLTAGE, NULL), MXS_ADC_CHAN(11, IIO_VOLTAGE, NULL), MXS_ADC_CHAN(12, IIO_VOLTAGE, "USB_DP"), MXS_ADC_CHAN(13, IIO_VOLTAGE, "USB_DN"), MXS_ADC_CHAN(14, IIO_VOLTAGE, "VBG"), MXS_ADC_CHAN(15, IIO_VOLTAGE, "VDD5V"), }; static const struct iio_chan_spec mx28_lradc_chan_spec[] = { MXS_ADC_CHAN(0, IIO_VOLTAGE, "LRADC0"), MXS_ADC_CHAN(1, IIO_VOLTAGE, "LRADC1"), MXS_ADC_CHAN(2, IIO_VOLTAGE, "LRADC2"), MXS_ADC_CHAN(3, IIO_VOLTAGE, "LRADC3"), MXS_ADC_CHAN(4, IIO_VOLTAGE, "LRADC4"), MXS_ADC_CHAN(5, IIO_VOLTAGE, "LRADC5"), MXS_ADC_CHAN(6, IIO_VOLTAGE, "LRADC6"), MXS_ADC_CHAN(7, IIO_VOLTAGE, "VBATT"), /* Combined Temperature sensors */ { .type = IIO_TEMP, .indexed = 1, .scan_index = 8, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_SCALE), .channel = 8, .scan_type = {.sign = 'u', .realbits = 18, .storagebits = 32,}, .datasheet_name = "TEMP_DIE", }, /* Hidden channel to keep indexes */ { .type = IIO_TEMP, .indexed = 1, .scan_index = -1, .channel = 9, }, MXS_ADC_CHAN(10, IIO_VOLTAGE, "VDDIO"), MXS_ADC_CHAN(11, IIO_VOLTAGE, "VTH"), MXS_ADC_CHAN(12, IIO_VOLTAGE, "VDDA"), MXS_ADC_CHAN(13, IIO_VOLTAGE, "VDDD"), MXS_ADC_CHAN(14, IIO_VOLTAGE, "VBG"), MXS_ADC_CHAN(15, IIO_VOLTAGE, "VDD5V"), }; static void mxs_lradc_adc_hw_init(struct mxs_lradc_adc *adc) { /* The ADC always uses DELAY CHANNEL 0. */ const u32 adc_cfg = (1 << (LRADC_DELAY_TRIGGER_DELAYS_OFFSET + 0)) | (LRADC_DELAY_TIMER_PER << LRADC_DELAY_DELAY_OFFSET); /* Configure DELAY CHANNEL 0 for generic ADC sampling. */ writel(adc_cfg, adc->base + LRADC_DELAY(0)); /* * Start internal temperature sensing by clearing bit * HW_LRADC_CTRL2_TEMPSENSE_PWD. This bit can be left cleared * after power up. */ writel(0, adc->base + LRADC_CTRL2); } static void mxs_lradc_adc_hw_stop(struct mxs_lradc_adc *adc) { writel(0, adc->base + LRADC_DELAY(0)); } static int mxs_lradc_adc_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct mxs_lradc *lradc = dev_get_drvdata(dev->parent); struct mxs_lradc_adc *adc; struct iio_dev *iio; struct resource *iores; int ret, irq, virq, i, s, n; u64 scale_uv; const char **irq_name; /* Allocate the IIO device. */ iio = devm_iio_device_alloc(dev, sizeof(*adc)); if (!iio) { dev_err(dev, "Failed to allocate IIO device\n"); return -ENOMEM; } adc = iio_priv(iio); adc->lradc = lradc; adc->dev = dev; iores = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!iores) return -EINVAL; adc->base = devm_ioremap(dev, iores->start, resource_size(iores)); if (!adc->base) return -ENOMEM; init_completion(&adc->completion); spin_lock_init(&adc->lock); platform_set_drvdata(pdev, iio); iio->name = pdev->name; iio->dev.of_node = dev->parent->of_node; iio->info = &mxs_lradc_adc_iio_info; iio->modes = INDIO_DIRECT_MODE; if (lradc->soc == IMX23_LRADC) { iio->channels = mx23_lradc_chan_spec; iio->num_channels = ARRAY_SIZE(mx23_lradc_chan_spec); irq_name = mx23_lradc_adc_irq_names; n = ARRAY_SIZE(mx23_lradc_adc_irq_names); } else { iio->channels = mx28_lradc_chan_spec; iio->num_channels = ARRAY_SIZE(mx28_lradc_chan_spec); irq_name = mx28_lradc_adc_irq_names; n = ARRAY_SIZE(mx28_lradc_adc_irq_names); } ret = stmp_reset_block(adc->base); if (ret) return ret; for (i = 0; i < n; i++) { irq = platform_get_irq_byname(pdev, irq_name[i]); if (irq < 0) return irq; virq = irq_of_parse_and_map(dev->parent->of_node, irq); ret = devm_request_irq(dev, virq, mxs_lradc_adc_handle_irq, 0, irq_name[i], iio); if (ret) return ret; } ret = mxs_lradc_adc_trigger_init(iio); if (ret) return ret; ret = iio_triggered_buffer_setup(iio, &iio_pollfunc_store_time, &mxs_lradc_adc_trigger_handler, &mxs_lradc_adc_buffer_ops); if (ret) goto err_trig; adc->vref_mv = mxs_lradc_adc_vref_mv[lradc->soc]; /* Populate available ADC input ranges */ for (i = 0; i < LRADC_MAX_TOTAL_CHANS; i++) { for (s = 0; s < ARRAY_SIZE(adc->scale_avail[i]); s++) { /* * [s=0] = optional divider by two disabled (default) * [s=1] = optional divider by two enabled * * The scale is calculated by doing: * Vref >> (realbits - s) * which multiplies by two on the second component * of the array. */ scale_uv = ((u64)adc->vref_mv[i] * 100000000) >> (LRADC_RESOLUTION - s); adc->scale_avail[i][s].nano = do_div(scale_uv, 100000000) * 10; adc->scale_avail[i][s].integer = scale_uv; } } /* Configure the hardware. */ mxs_lradc_adc_hw_init(adc); /* Register IIO device. */ ret = iio_device_register(iio); if (ret) { dev_err(dev, "Failed to register IIO device\n"); goto err_dev; } return 0; err_dev: mxs_lradc_adc_hw_stop(adc); iio_triggered_buffer_cleanup(iio); err_trig: mxs_lradc_adc_trigger_remove(iio); return ret; } static void mxs_lradc_adc_remove(struct platform_device *pdev) { struct iio_dev *iio = platform_get_drvdata(pdev); struct mxs_lradc_adc *adc = iio_priv(iio); iio_device_unregister(iio); mxs_lradc_adc_hw_stop(adc); iio_triggered_buffer_cleanup(iio); mxs_lradc_adc_trigger_remove(iio); } static struct platform_driver mxs_lradc_adc_driver = { .driver = { .name = "mxs-lradc-adc", }, .probe = mxs_lradc_adc_probe, .remove = mxs_lradc_adc_remove, }; module_platform_driver(mxs_lradc_adc_driver); MODULE_AUTHOR("Marek Vasut "); MODULE_DESCRIPTION("Freescale MXS LRADC driver general purpose ADC driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:mxs-lradc-adc");