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Subject[PATCH v10 2/5] iio: adc: mxs-lradc: Add support for adc driver
Date
Add support for sixteen-channel 12-bit resolution ADC and its functions,
which include general-purpose ADC readings, battery voltage measurement,
and die temperature measurement.

Signed-off-by: Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
Reviewed-by: Jonathan Cameron <jic23@kernel.org>
---
Changes in v10:
- none

Changes in v9:
- none

Changes in v8:
- rebase onto 4.9-rc1

Changes in v7:
- none

Changes in v6:
- update copyright

Changes in v5:
- add field void __iomem *base to struct mxs_lradc_adc
- change arguments in all functions for accessing I/O memory
to follow the previous change.
- use devm_ioremap for mapping I/O memory

Changes in v4:
- update copyright
- use platform_get_irq_byname
- use irq_of_parse_and_map

Changes in v3:
- make buffer large enough for timestamps
- remove unnecessary blank lines

Changes in v2:
- improve commit message
- do not change spacing in Kconfig
- impove formating
- remove wrapper show_scale_avail
- use correct syntax for comments
- use devm_iio_trigger_alloc
- do not allocate buffer dynamically
- use iio_device_claim_*_mode helpers
- add spinlock in struct mxs_lradc_ts to enable locking in interrupt handler
- only grab irqs that are relevant to adc
- remove blank line at the end of the file
- change licence to GPL
- add copyright

drivers/iio/adc/Kconfig | 13 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/mxs-lradc-adc.c | 845 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 859 insertions(+)
create mode 100644 drivers/iio/adc/mxs-lradc-adc.c

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 57ebb99..ad6046a 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -219,6 +219,19 @@ config EXYNOS_ADC
To compile this driver as a module, choose M here: the module will be
called exynos_adc.

+config MXS_LRADC_ADC
+ tristate "Freescale i.MX23/i.MX28 LRADC ADC"
+ depends on MFD_MXS_LRADC
+ select IIO_BUFFER
+ select IIO_TRIGGERED_BUFFER
+ help
+ Say yes here to build support for the ADC functions of the
+ i.MX23/i.MX28 LRADC. This includes general-purpose ADC readings,
+ battery voltage measurement, and die temperature measurement.
+
+ This driver can also be built as a module. If so, the module will be
+ called mxs-lradc-adc.
+
config FSL_MX25_ADC
tristate "Freescale MX25 ADC driver"
depends on MFD_MX25_TSADC
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 96894b3..4b2cf9b 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -35,6 +35,7 @@ obj-$(CONFIG_MCP320X) += mcp320x.o
obj-$(CONFIG_MCP3422) += mcp3422.o
obj-$(CONFIG_MEDIATEK_MT6577_AUXADC) += mt6577_auxadc.o
obj-$(CONFIG_MEN_Z188_ADC) += men_z188_adc.o
+obj-$(CONFIG_MXS_LRADC_ADC) += mxs-lradc-adc.o
obj-$(CONFIG_MXS_LRADC) += mxs-lradc.o
obj-$(CONFIG_NAU7802) += nau7802.o
obj-$(CONFIG_PALMAS_GPADC) += palmas_gpadc.o
diff --git a/drivers/iio/adc/mxs-lradc-adc.c b/drivers/iio/adc/mxs-lradc-adc.c
new file mode 100644
index 0000000..6943220
--- /dev/null
+++ b/drivers/iio/adc/mxs-lradc-adc.c
@@ -0,0 +1,845 @@
+/*
+ * Freescale MXS LRADC ADC driver
+ *
+ * Copyright (c) 2012 DENX Software Engineering, GmbH.
+ * Copyright (c) 2016 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)
+ mxs_lradc_reg_clear(adc->base, LRADC_CTRL1_LRADC_IRQ_EN(0),
+ LRADC_CTRL1);
+ mxs_lradc_reg_clear(adc->base, 0x1, LRADC_CTRL0);
+
+ /* Enable / disable the divider per requirement */
+ if (test_bit(chan, &adc->is_divided))
+ mxs_lradc_reg_set(adc->base,
+ 1 << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET,
+ LRADC_CTRL2);
+ else
+ mxs_lradc_reg_clear(adc->base,
+ 1 << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET,
+ LRADC_CTRL2);
+
+ /* Clean the slot's previous content, then set new one. */
+ mxs_lradc_reg_clear(adc->base, LRADC_CTRL4_LRADCSELECT_MASK(0),
+ LRADC_CTRL4);
+ mxs_lradc_reg_set(adc->base, chan, LRADC_CTRL4);
+
+ mxs_lradc_reg_wrt(adc->base, 0, LRADC_CH(0));
+
+ /* Enable the IRQ and start sampling the channel. */
+ mxs_lradc_reg_set(adc->base, LRADC_CTRL1_LRADC_IRQ_EN(0), LRADC_CTRL1);
+ mxs_lradc_reg_set(adc->base, BIT(0), LRADC_CTRL0);
+
+ /* 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:
+ mxs_lradc_reg_clear(adc->base, LRADC_CTRL1_LRADC_IRQ_EN(0),
+ LRADC_CTRL1);
+
+ 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) \
+static IIO_DEVICE_ATTR(in_voltage##ch##_scale_available, S_IRUGO, \
+ 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);
+ }
+
+ mxs_lradc_reg_clear(adc->base, reg & mxs_lradc_irq_mask(lradc),
+ LRADC_CTRL1);
+
+ 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));
+ mxs_lradc_reg_wrt(adc->base, chan_value, 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;
+
+ mxs_lradc_reg_wrt(adc->base, LRADC_DELAY_KICK, 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)
+ mxs_lradc_reg_clear(adc->base,
+ lradc->buffer_vchans << LRADC_CTRL1_LRADC_IRQ_EN_OFFSET,
+ LRADC_CTRL1);
+ mxs_lradc_reg_clear(adc->base, lradc->buffer_vchans, LRADC_CTRL0);
+
+ 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);
+ mxs_lradc_reg_wrt(adc->base, chan_value, LRADC_CH(ofs));
+ bitmap_set(&enable, ofs, 1);
+ ofs++;
+ }
+
+ mxs_lradc_reg_clear(adc->base, LRADC_DELAY_TRIGGER_LRADCS_MASK |
+ LRADC_DELAY_KICK, LRADC_DELAY(0));
+ mxs_lradc_reg_clear(adc->base, ctrl4_clr, LRADC_CTRL4);
+ mxs_lradc_reg_set(adc->base, ctrl4_set, LRADC_CTRL4);
+ mxs_lradc_reg_set(adc->base, ctrl1_irq, LRADC_CTRL1);
+ mxs_lradc_reg_set(adc->base,
+ enable << LRADC_DELAY_TRIGGER_LRADCS_OFFSET,
+ LRADC_DELAY(0));
+
+ 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;
+
+ mxs_lradc_reg_clear(adc->base, LRADC_DELAY_TRIGGER_LRADCS_MASK |
+ LRADC_DELAY_KICK, LRADC_DELAY(0));
+
+ mxs_lradc_reg_clear(adc->base, lradc->buffer_vchans, LRADC_CTRL0);
+ if (lradc->soc == IMX28_LRADC)
+ mxs_lradc_reg_clear(adc->base,
+ lradc->buffer_vchans << LRADC_CTRL1_LRADC_IRQ_EN_OFFSET,
+ LRADC_CTRL1);
+
+ 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. */
+ mxs_lradc_reg_wrt(adc->base, adc_cfg, LRADC_DELAY(0));
+
+ /*
+ * Start internal temperature sensing by clearing bit
+ * HW_LRADC_CTRL2_TEMPSENSE_PWD. This bit can be left cleared
+ * after power up.
+ */
+ mxs_lradc_reg_wrt(adc->base, 0, LRADC_CTRL2);
+}
+
+static void mxs_lradc_adc_hw_stop(struct mxs_lradc_adc *adc)
+{
+ mxs_lradc_reg_wrt(adc->base, 0, LRADC_DELAY(0));
+}
+
+static int mxs_lradc_adc_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct mxs_lradc *lradc = dev_get_platdata(dev);
+ 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");
--
1.9.1
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  Last update: 2016-11-20 12:16    [W:0.085 / U:0.508 seconds]
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