diff options
Diffstat (limited to 'drivers/iio/adc/mxs-lradc-adc.c')
| -rw-r--r-- | drivers/iio/adc/mxs-lradc-adc.c | 843 |
1 files changed, 843 insertions, 0 deletions
diff --git a/drivers/iio/adc/mxs-lradc-adc.c b/drivers/iio/adc/mxs-lradc-adc.c new file mode 100644 index 000000000000..b0c7d8ee5cb8 --- /dev/null +++ b/drivers/iio/adc/mxs-lradc-adc.c @@ -0,0 +1,843 @@ +/* + * Freescale MXS LRADC ADC driver + * + * Copyright (c) 2012 DENX Software Engineering, GmbH. + * Copyright (c) 2017 Ksenija Stanojevic <ksenija.stanojevic@gmail.com> + * + * Authors: + * Marek Vasut <marex@denx.de> + * Ksenija Stanojevic <ksenija.stanojevic@gmail.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/completion.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/interrupt.h> +#include <linux/mfd/core.h> +#include <linux/mfd/mxs-lradc.h> +#include <linux/module.h> +#include <linux/of_irq.h> +#include <linux/platform_device.h> +#include <linux/sysfs.h> + +#include <linux/iio/buffer.h> +#include <linux/iio/iio.h> +#include <linux/iio/trigger.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/iio/triggered_buffer.h> +#include <linux/iio/sysfs.h> + +/* + * 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 + +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", +}; + +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; + u32 buffer[10]; + 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) + +SHOW_SCALE_AVAILABLE_ATTR(0); +SHOW_SCALE_AVAILABLE_ATTR(1); +SHOW_SCALE_AVAILABLE_ATTR(2); +SHOW_SCALE_AVAILABLE_ATTR(3); +SHOW_SCALE_AVAILABLE_ATTR(4); +SHOW_SCALE_AVAILABLE_ATTR(5); +SHOW_SCALE_AVAILABLE_ATTR(6); +SHOW_SCALE_AVAILABLE_ATTR(7); +SHOW_SCALE_AVAILABLE_ATTR(10); +SHOW_SCALE_AVAILABLE_ATTR(11); +SHOW_SCALE_AVAILABLE_ATTR(12); +SHOW_SCALE_AVAILABLE_ATTR(13); +SHOW_SCALE_AVAILABLE_ATTR(14); +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 = { + .driver_module = THIS_MODULE, + .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 = { + .owner = THIS_MODULE, + .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->id); + + 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, + .postenable = &iio_triggered_buffer_postenable, + .predisable = &iio_triggered_buffer_predisable, + .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); + adc->base = devm_ioremap(dev, iores->start, resource_size(iores)); + if (IS_ERR(adc->base)) + return PTR_ERR(adc->base); + + init_completion(&adc->completion); + spin_lock_init(&adc->lock); + + platform_set_drvdata(pdev, iio); + + iio->name = pdev->name; + iio->dev.parent = dev; + iio->dev.of_node = dev->parent->of_node; + iio->info = &mxs_lradc_adc_iio_info; + iio->modes = INDIO_DIRECT_MODE; + iio->masklength = LRADC_MAX_TOTAL_CHANS; + + 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) + goto err_trig; + + ret = iio_triggered_buffer_setup(iio, &iio_pollfunc_store_time, + &mxs_lradc_adc_trigger_handler, + &mxs_lradc_adc_buffer_ops); + if (ret) + return ret; + + 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); + mxs_lradc_adc_trigger_remove(iio); +err_trig: + iio_triggered_buffer_cleanup(iio); + return ret; +} + +static int 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); + mxs_lradc_adc_trigger_remove(iio); + iio_triggered_buffer_cleanup(iio); + + return 0; +} + +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 <marex@denx.de>"); +MODULE_DESCRIPTION("Freescale MXS LRADC driver general purpose ADC driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:mxs-lradc-adc"); |