[PATCH 1/3] iio: adc: hi-843x: Holt HI-8435/8436/8437 descrete ADC

From: Vladimir Barinov
Date: Mon Jun 01 2015 - 08:20:24 EST


Add Holt descrete ADC driver for HI-8435/8436/8437 chips

Signed-off-by: Vladimir Barinov <vladimir.barinov@xxxxxxxxxxxxxxxxxx>
---
drivers/iio/adc/Kconfig | 12 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/hi-843x.c | 777 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 790 insertions(+)
create mode 100644 drivers/iio/adc/hi-843x.c

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index e36a73e..71b0efc 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -164,6 +164,18 @@ config EXYNOS_ADC
of SoCs for drivers such as the touchscreen and hwmon to use to share
this resource.

+config HI_843X
+ tristate "Holt Integrated Circuits HI-8435/8436/8437"
+ select IIO_BUFFER
+ select IIO_TRIGGERED_BUFFER
+ depends on SPI
+ help
+ If you say yes here you get support for Holt Integrated Circuits
+ HI-8435/8436/8437 chip.
+
+ This driver can also be built as a module. If so, the module will be
+ called hi-843x.
+
config LP8788_ADC
tristate "LP8788 ADC driver"
depends on MFD_LP8788
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 3930e63..65f54c2 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_AXP288_ADC) += axp288_adc.o
obj-$(CONFIG_DA9150_GPADC) += da9150-gpadc.o
obj-$(CONFIG_CC10001_ADC) += cc10001_adc.o
obj-$(CONFIG_EXYNOS_ADC) += exynos_adc.o
+obj-$(CONFIG_HI_843X) += hi-843x.o
obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o
obj-$(CONFIG_MAX1027) += max1027.o
obj-$(CONFIG_MAX1363) += max1363.o
diff --git a/drivers/iio/adc/hi-843x.c b/drivers/iio/adc/hi-843x.c
new file mode 100644
index 0000000..ccc46e7
--- /dev/null
+++ b/drivers/iio/adc/hi-843x.c
@@ -0,0 +1,777 @@
+/*
+ * Holt Integrated Circuits HI-8435/8436/8437 discrete ADC driver
+ *
+ * Copyright (C) 2015 Zodiac Inflight Innovations
+ * Copyright (C) 2015 Cogent Embedded, Inc.
+ *
+ * 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.
+ */
+
+#include <linux/delay.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_gpio.h>
+#include <linux/spi/spi.h>
+#include <linux/workqueue.h>
+
+#include <linux/interrupt.h>
+
+#define DRV_NAME "hi-843x"
+
+/* Register offsets for HI-843X */
+#define HI843X_CTRL_REG 0x02
+#define HI843X_PSEN_REG 0x04
+#define HI843X_TMDATA_REG 0x1E
+#define HI843X_GOCENHYS_REG 0x3A
+#define HI843X_SOCENHYS_REG 0x3C
+#define HI843X_SO7_0_REG 0x10
+#define HI843X_SO15_8_REG 0x12
+#define HI843X_SO23_16_REG 0x14
+#define HI843X_SO31_24_REG 0x16
+#define HI843X_SO31_0_REG 0x78
+
+#define HI843X_WRITE_OPCODE 0x00
+#define HI843X_READ_OPCODE 0x80
+
+/* THRESHOLD mask */
+#define HI843X_THRESHOLD_MAX 0x3f
+#define HI843X_THRESHOLD_MASK 0xff
+
+/* CTRL register bits */
+#define HI843X_CTRL_TEST 0x01
+#define HI843X_CTRL_SRST 0x02
+
+#define HI843X_DEBOUNCE_SOFT_DELAY_MAX 1000 /* ms */
+#define HI843X_DEBOUNCE_SOFT_DELAY_DEF 100 /* ms */
+
+struct hi843x_priv {
+ struct spi_device *spi;
+ struct mutex lock;
+ struct delayed_work work;
+
+ int mr_gpio;
+ bool debounce_soft;
+ int debounce_soft_delay;
+ int debounce_soft_val;
+
+ void *iio_buffer;
+ u8 reg_buffer[4] ____cacheline_aligned;
+};
+
+static int hi843x_readb(struct hi843x_priv *priv, u8 reg, u8 *val)
+{
+ reg |= HI843X_READ_OPCODE;
+ return spi_write_then_read(priv->spi, &reg, 1, val, 1);
+}
+
+static int hi843x_readw(struct hi843x_priv *priv, u8 reg, u16 *val)
+{
+ int ret;
+
+ reg |= HI843X_READ_OPCODE;
+ ret = spi_write_then_read(priv->spi, &reg, 1, val, 2);
+ *val = swab16p(val);
+
+ return ret;
+}
+
+static int hi843x_readl(struct hi843x_priv *priv, u8 reg, u32 *val)
+{
+ int ret;
+
+ reg |= HI843X_READ_OPCODE;
+ ret = spi_write_then_read(priv->spi, &reg, 1, val, 4);
+ *val = swab32p(val);
+
+ return ret;
+}
+
+static int hi843x_writeb(struct hi843x_priv *priv, u8 reg, u8 val)
+{
+ priv->reg_buffer[0] = reg | HI843X_WRITE_OPCODE;
+ priv->reg_buffer[1] = val;
+
+ return spi_write(priv->spi, priv->reg_buffer, 2);
+}
+
+static int hi843x_writew(struct hi843x_priv *priv, u8 reg, u16 val)
+{
+ priv->reg_buffer[0] = reg | HI843X_WRITE_OPCODE;
+ priv->reg_buffer[1] = (val >> 8) & 0xff;
+ priv->reg_buffer[2] = val & 0xff;
+
+ return spi_write(priv->spi, priv->reg_buffer, 3);
+}
+
+ssize_t hi843x_debounce_soft_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct hi843x_priv *priv = iio_priv(dev_to_iio_dev(dev));
+
+ return sprintf(buf, "%d\n", priv->debounce_soft);
+}
+
+ssize_t hi843x_debounce_soft_delay_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct hi843x_priv *priv = iio_priv(dev_to_iio_dev(dev));
+
+ return sprintf(buf, "%d\n", priv->debounce_soft_delay);
+}
+
+ssize_t hi843x_sensing_mode_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct hi843x_priv *priv = iio_priv(dev_to_iio_dev(dev));
+ int ret;
+ u8 reg;
+
+ ret = hi843x_readb(priv, HI843X_PSEN_REG, &reg);
+ if (ret < 0)
+ return ret;
+
+ return sprintf(buf, "%d\n", reg);
+}
+
+ssize_t hi843x_test_enable_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct hi843x_priv *priv = iio_priv(dev_to_iio_dev(dev));
+ int ret;
+ u8 reg;
+
+ ret = hi843x_readb(priv, HI843X_CTRL_REG, &reg);
+ if (ret < 0)
+ return ret;
+
+ return sprintf(buf, "%d\n", reg & HI843X_CTRL_TEST);
+}
+
+ssize_t hi843x_test_mode_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct hi843x_priv *priv = iio_priv(dev_to_iio_dev(dev));
+ int ret;
+ u8 reg;
+
+ ret = hi843x_readb(priv, HI843X_TMDATA_REG, &reg);
+ if (ret < 0)
+ return ret;
+
+ return sprintf(buf, "%d\n", reg);
+}
+
+ssize_t hi843x_debounce_soft_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct hi843x_priv *priv = iio_priv(dev_to_iio_dev(dev));
+ unsigned int val;
+ int ret;
+
+ ret = kstrtouint(buf, 10, &val);
+ if (ret)
+ return ret;
+
+ priv->debounce_soft = !!val;
+
+ return len;
+}
+
+ssize_t hi843x_debounce_soft_delay_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct hi843x_priv *priv = iio_priv(dev_to_iio_dev(dev));
+ unsigned int val;
+ int ret;
+
+ ret = kstrtouint(buf, 10, &val);
+ if (ret)
+ return ret;
+
+ if (val > HI843X_DEBOUNCE_SOFT_DELAY_MAX)
+ val = HI843X_DEBOUNCE_SOFT_DELAY_MAX;
+
+ priv->debounce_soft_delay = val;
+
+ return len;
+}
+
+ssize_t hi843x_sensing_mode_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct hi843x_priv *priv = iio_priv(dev_to_iio_dev(dev));
+ unsigned int val;
+ int ret;
+
+ ret = kstrtouint(buf, 10, &val);
+ if (ret)
+ return ret;
+
+ hi843x_writeb(priv, HI843X_PSEN_REG, val & 0xf);
+
+ return len;
+}
+
+ssize_t hi843x_test_enable_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct hi843x_priv *priv = iio_priv(dev_to_iio_dev(dev));
+ unsigned int val;
+ int ret;
+
+ ret = kstrtouint(buf, 10, &val);
+ if (ret)
+ return ret;
+
+ hi843x_writeb(priv, HI843X_CTRL_REG, val ? HI843X_CTRL_TEST : 0);
+
+ return len;
+}
+
+ssize_t hi843x_test_mode_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct hi843x_priv *priv = iio_priv(dev_to_iio_dev(dev));
+ unsigned int val;
+ int ret;
+
+ ret = kstrtouint(buf, 10, &val);
+ if (ret)
+ return ret;
+
+ hi843x_writeb(priv, HI843X_TMDATA_REG, val & 0xf);
+
+ return len;
+}
+
+ssize_t hi843x_threshold_gohys_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct hi843x_priv *priv = iio_priv(dev_to_iio_dev(dev));
+ int ret;
+ u16 reg;
+
+ ret = hi843x_readw(priv, HI843X_GOCENHYS_REG, &reg);
+ if (ret < 0)
+ return ret;
+
+ return sprintf(buf, "%d\n", (reg >> 8) & HI843X_THRESHOLD_MASK);
+}
+
+ssize_t hi843x_threshold_gocval_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct hi843x_priv *priv = iio_priv(dev_to_iio_dev(dev));
+ int ret;
+ u16 reg;
+
+ ret = hi843x_readw(priv, HI843X_GOCENHYS_REG, &reg);
+ if (ret < 0)
+ return ret;
+
+ return sprintf(buf, "%d\n", reg & HI843X_THRESHOLD_MASK);
+}
+
+ssize_t hi843x_threshold_sohys_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct hi843x_priv *priv = iio_priv(dev_to_iio_dev(dev));
+ int ret;
+ u16 reg;
+
+ ret = hi843x_readw(priv, HI843X_SOCENHYS_REG, &reg);
+ if (ret < 0)
+ return ret;
+
+ return sprintf(buf, "%d\n", (reg >> 8) & HI843X_THRESHOLD_MASK);
+}
+
+ssize_t hi843x_threshold_socval_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct hi843x_priv *priv = iio_priv(dev_to_iio_dev(dev));
+ int ret;
+ u16 reg;
+
+ ret = hi843x_readw(priv, HI843X_SOCENHYS_REG, &reg);
+ if (ret < 0)
+ return ret;
+
+ return sprintf(buf, "%d\n", reg & HI843X_THRESHOLD_MASK);
+}
+
+ssize_t hi843x_threshold_gohys_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct hi843x_priv *priv = iio_priv(dev_to_iio_dev(dev));
+ unsigned int val, ret;
+ u16 reg;
+
+ ret = kstrtouint(buf, 10, &val);
+ if (ret)
+ return ret;
+
+ if (val > HI843X_THRESHOLD_MAX)
+ return -EINVAL;
+
+ mutex_lock(&priv->lock);
+
+ ret = hi843x_readw(priv, HI843X_GOCENHYS_REG, &reg);
+ if (ret < 0) {
+ mutex_unlock(&priv->lock);
+ return ret;
+ }
+ reg &= ~(HI843X_THRESHOLD_MASK << 8);
+ reg |= (val << 8);
+ hi843x_writew(priv, HI843X_GOCENHYS_REG, reg);
+
+ mutex_unlock(&priv->lock);
+
+ return len;
+}
+
+ssize_t hi843x_threshold_gocval_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct hi843x_priv *priv = iio_priv(dev_to_iio_dev(dev));
+ unsigned int val, ret;
+ u16 reg;
+
+ ret = kstrtouint(buf, 10, &val);
+ if (ret)
+ return ret;
+
+ if (val > HI843X_THRESHOLD_MAX)
+ return -EINVAL;
+
+ mutex_lock(&priv->lock);
+
+ ret = hi843x_readw(priv, HI843X_GOCENHYS_REG, &reg);
+ if (ret < 0) {
+ mutex_unlock(&priv->lock);
+ return ret;
+ }
+ reg &= ~HI843X_THRESHOLD_MASK;
+ reg |= val;
+ hi843x_writew(priv, HI843X_GOCENHYS_REG, reg);
+
+ mutex_unlock(&priv->lock);
+
+ return len;
+}
+
+ssize_t hi843x_threshold_sohys_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct hi843x_priv *priv = iio_priv(dev_to_iio_dev(dev));
+ unsigned int val, ret;
+ u16 reg;
+
+ ret = kstrtouint(buf, 10, &val);
+ if (ret)
+ return ret;
+
+ if (val > HI843X_THRESHOLD_MAX)
+ return -EINVAL;
+
+ mutex_lock(&priv->lock);
+
+ ret = hi843x_readw(priv, HI843X_SOCENHYS_REG, &reg);
+ if (ret < 0) {
+ mutex_unlock(&priv->lock);
+ return ret;
+ }
+ reg &= ~(HI843X_THRESHOLD_MASK << 8);
+ reg |= (val << 8);
+ hi843x_writew(priv, HI843X_SOCENHYS_REG, reg);
+
+ mutex_unlock(&priv->lock);
+
+ return len;
+}
+
+ssize_t hi843x_threshold_socval_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct hi843x_priv *priv = iio_priv(dev_to_iio_dev(dev));
+ unsigned int val, ret;
+ u16 reg;
+
+ ret = kstrtouint(buf, 10, &val);
+ if (ret)
+ return ret;
+
+ if (val > HI843X_THRESHOLD_MAX)
+ return -EINVAL;
+
+ mutex_lock(&priv->lock);
+
+ ret = hi843x_readw(priv, HI843X_SOCENHYS_REG, &reg);
+ if (ret < 0) {
+ mutex_unlock(&priv->lock);
+ return ret;
+ }
+ reg &= ~HI843X_THRESHOLD_MASK;
+ reg |= val;
+ hi843x_writew(priv, HI843X_SOCENHYS_REG, reg);
+
+ mutex_unlock(&priv->lock);
+
+ return len;
+}
+
+static IIO_DEVICE_ATTR(debounce_soft, S_IRUGO | S_IWUSR,
+ hi843x_debounce_soft_show, hi843x_debounce_soft_store, 0);
+static IIO_DEVICE_ATTR(debounce_soft_delay, S_IRUGO | S_IWUSR,
+ hi843x_debounce_soft_delay_show, hi843x_debounce_soft_delay_store, 0);
+static IIO_DEVICE_ATTR(sensing_mode, S_IRUGO | S_IWUSR,
+ hi843x_sensing_mode_show, hi843x_sensing_mode_store, 0);
+static IIO_DEVICE_ATTR(test_enable, S_IRUGO | S_IWUSR,
+ hi843x_test_enable_show, hi843x_test_enable_store, 0);
+static IIO_DEVICE_ATTR(test_mode, S_IRUGO | S_IWUSR,
+ hi843x_test_mode_show, hi843x_test_mode_store, 0);
+static IIO_DEVICE_ATTR(threshold_gohys, S_IRUGO | S_IWUSR,
+ hi843x_threshold_gohys_show, hi843x_threshold_gohys_store, 0);
+static IIO_DEVICE_ATTR(threshold_gocval, S_IRUGO | S_IWUSR,
+ hi843x_threshold_gocval_show, hi843x_threshold_gocval_store, 0);
+static IIO_DEVICE_ATTR(threshold_sohys, S_IRUGO | S_IWUSR,
+ hi843x_threshold_sohys_show, hi843x_threshold_sohys_store, 0);
+static IIO_DEVICE_ATTR(threshold_socval, S_IRUGO | S_IWUSR,
+ hi843x_threshold_socval_show, hi843x_threshold_socval_store, 0);
+
+static struct attribute *hi843x_attributes[] = {
+ &iio_dev_attr_debounce_soft.dev_attr.attr,
+ &iio_dev_attr_debounce_soft_delay.dev_attr.attr,
+ &iio_dev_attr_sensing_mode.dev_attr.attr,
+ &iio_dev_attr_test_enable.dev_attr.attr,
+ &iio_dev_attr_test_mode.dev_attr.attr,
+ &iio_dev_attr_threshold_gohys.dev_attr.attr,
+ &iio_dev_attr_threshold_gocval.dev_attr.attr,
+ &iio_dev_attr_threshold_sohys.dev_attr.attr,
+ &iio_dev_attr_threshold_socval.dev_attr.attr,
+ NULL,
+};
+
+static struct attribute_group hi843x_attribute_group = {
+ .attrs = hi843x_attributes,
+};
+
+static int hi843x_read_raw(struct iio_dev *idev,
+ struct iio_chan_spec const *channel, int *val,
+ int *val2, long mask)
+{
+ struct hi843x_priv *priv = iio_priv(idev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_PROCESSED:
+ case IIO_CHAN_INFO_RAW:
+ ret = hi843x_readl(priv, HI843X_SO31_0_REG, val);
+ if (ret < 0)
+ return ret;
+
+ if (mask == IIO_CHAN_INFO_RAW)
+ *val = !!(*val & BIT(channel->channel));
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+}
+
+#define HI843X_VOLTAGE_CHANNEL(num) \
+ { \
+ .type = IIO_VOLTAGE, \
+ .indexed = 1, \
+ .channel = num, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .scan_index = num, \
+ .scan_type = { \
+ .sign = 'u', \
+ .realbits = 1, \
+ .storagebits = 8, \
+ }, \
+ }
+
+static const struct iio_chan_spec hi843x_channels[] = {
+ HI843X_VOLTAGE_CHANNEL(0),
+ HI843X_VOLTAGE_CHANNEL(1),
+ HI843X_VOLTAGE_CHANNEL(2),
+ HI843X_VOLTAGE_CHANNEL(3),
+ HI843X_VOLTAGE_CHANNEL(4),
+ HI843X_VOLTAGE_CHANNEL(5),
+ HI843X_VOLTAGE_CHANNEL(6),
+ HI843X_VOLTAGE_CHANNEL(7),
+ HI843X_VOLTAGE_CHANNEL(8),
+ HI843X_VOLTAGE_CHANNEL(9),
+ HI843X_VOLTAGE_CHANNEL(10),
+ HI843X_VOLTAGE_CHANNEL(11),
+ HI843X_VOLTAGE_CHANNEL(12),
+ HI843X_VOLTAGE_CHANNEL(13),
+ HI843X_VOLTAGE_CHANNEL(14),
+ HI843X_VOLTAGE_CHANNEL(15),
+ HI843X_VOLTAGE_CHANNEL(16),
+ HI843X_VOLTAGE_CHANNEL(17),
+ HI843X_VOLTAGE_CHANNEL(18),
+ HI843X_VOLTAGE_CHANNEL(19),
+ HI843X_VOLTAGE_CHANNEL(20),
+ HI843X_VOLTAGE_CHANNEL(21),
+ HI843X_VOLTAGE_CHANNEL(22),
+ HI843X_VOLTAGE_CHANNEL(23),
+ HI843X_VOLTAGE_CHANNEL(24),
+ HI843X_VOLTAGE_CHANNEL(25),
+ HI843X_VOLTAGE_CHANNEL(26),
+ HI843X_VOLTAGE_CHANNEL(27),
+ HI843X_VOLTAGE_CHANNEL(28),
+ HI843X_VOLTAGE_CHANNEL(29),
+ HI843X_VOLTAGE_CHANNEL(30),
+ HI843X_VOLTAGE_CHANNEL(31),
+ {
+ .type = IIO_ALTVOLTAGE,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+ .scan_index = 32,
+ .scan_type = {
+ .sign = 'u',
+ .realbits = 32,
+ .storagebits = 32,
+ },
+ },
+ IIO_CHAN_SOFT_TIMESTAMP(33),
+};
+
+static const struct iio_info hi843x_info = {
+ .driver_module = THIS_MODULE,
+ .attrs = &hi843x_attribute_group,
+ .read_raw = hi843x_read_raw,
+};
+
+static void h843x_iio_push_to_buffers(struct iio_dev *idev, int val)
+{
+ struct hi843x_priv *priv = iio_priv(idev);
+ u8 *pbuffer = priv->iio_buffer;
+ int i;
+
+ for_each_set_bit(i, idev->active_scan_mask, idev->masklength) {
+ if (idev->channels[i].type == IIO_ALTVOLTAGE) {
+ *(u32 *)pbuffer = val;
+ pbuffer += 4;
+ } else {
+ *pbuffer = !!(val & BIT(i));
+ pbuffer++;
+ }
+ }
+ iio_push_to_buffers_with_timestamp(idev, priv->iio_buffer,
+ iio_get_time_ns());
+}
+
+static void hi843x_debounce_soft_work(struct work_struct *work)
+{
+ struct hi843x_priv *priv = container_of(work, struct hi843x_priv,
+ work.work);
+ struct iio_dev *idev = spi_get_drvdata(priv->spi);
+ int val, ret;
+
+ ret = hi843x_readl(priv, HI843X_SO31_0_REG, &val);
+ if (ret < 0)
+ return;
+
+ if (val == priv->debounce_soft_val)
+ h843x_iio_push_to_buffers(idev, val);
+ else
+ dev_warn(&priv->spi->dev, "filtered by soft debounce");
+}
+
+static irqreturn_t hi843x_trigger_handler(int irq, void *private)
+{
+ struct iio_poll_func *pf = private;
+ struct iio_dev *idev = pf->indio_dev;
+ struct hi843x_priv *priv = iio_priv(idev);
+ int val, ret;
+
+ ret = hi843x_readl(priv, HI843X_SO31_0_REG, &val);
+ if (ret < 0)
+ goto err_read;
+
+ if (priv->debounce_soft) {
+ priv->debounce_soft_val = val;
+ schedule_delayed_work(&priv->work,
+ msecs_to_jiffies(priv->debounce_soft_delay));
+ } else
+ h843x_iio_push_to_buffers(idev, val);
+
+err_read:
+ iio_trigger_notify_done(idev->trig);
+
+ return IRQ_HANDLED;
+}
+
+static int hi843x_buffer_postenable(struct iio_dev *idev)
+{
+ struct hi843x_priv *priv = iio_priv(idev);
+
+ priv->iio_buffer = kmalloc(idev->scan_bytes, GFP_KERNEL);
+ if (!priv->iio_buffer)
+ return -ENOMEM;
+
+ return iio_triggered_buffer_postenable(idev);
+}
+
+static int hi843x_buffer_predisable(struct iio_dev *idev)
+{
+ struct hi843x_priv *priv = iio_priv(idev);
+ int ret;
+
+ ret = iio_triggered_buffer_predisable(idev);
+ if (!ret)
+ kfree(priv->iio_buffer);
+
+ return ret;
+}
+
+static const struct iio_buffer_setup_ops hi843x_buffer_setup_ops = {
+ .postenable = &hi843x_buffer_postenable,
+ .predisable = &hi843x_buffer_predisable,
+};
+
+static const struct iio_trigger_ops hi843x_trigger_ops = {
+ .owner = THIS_MODULE,
+};
+
+static void hi843x_parse_dt(struct hi843x_priv *priv)
+{
+ struct device_node *np = priv->spi->dev.of_node;
+ int ret;
+
+ ret = of_get_named_gpio(np, "holt,mr-gpio", 0);
+ priv->mr_gpio = ret < 0 ? 0 : ret;
+
+ if (of_find_property(np, "holt,debounce-soft", NULL))
+ priv->debounce_soft = 1;
+
+ ret = of_property_read_u32(np, "holt,debounce-soft-delay",
+ &priv->debounce_soft_delay);
+ if (ret)
+ priv->debounce_soft_delay = HI843X_DEBOUNCE_SOFT_DELAY_DEF;
+}
+
+static int hi843x_probe(struct spi_device *spi)
+{
+ struct iio_dev *idev;
+ struct hi843x_priv *priv;
+ int ret;
+
+ idev = devm_iio_device_alloc(&spi->dev, sizeof(*priv));
+ if (!idev)
+ return -ENOMEM;
+
+ priv = iio_priv(idev);
+ priv->spi = spi;
+
+ if (spi->dev.of_node)
+ hi843x_parse_dt(priv);
+
+ spi_set_drvdata(spi, idev);
+ mutex_init(&priv->lock);
+ INIT_DELAYED_WORK(&priv->work, hi843x_debounce_soft_work);
+
+ idev->dev.parent = &spi->dev;
+ idev->name = spi_get_device_id(spi)->name;
+ idev->modes = INDIO_DIRECT_MODE;
+ idev->info = &hi843x_info;
+ idev->channels = hi843x_channels;
+ idev->num_channels = ARRAY_SIZE(hi843x_channels);
+
+ if (priv->mr_gpio) {
+ ret = devm_gpio_request(&spi->dev, priv->mr_gpio, idev->name);
+ if (!ret) {
+ /* chip hardware reset */
+ gpio_direction_output(priv->mr_gpio, 0);
+ udelay(5);
+ gpio_direction_output(priv->mr_gpio, 1);
+ }
+ } else {
+ /* chip software reset */
+ hi843x_writeb(priv, HI843X_CTRL_REG, HI843X_CTRL_SRST);
+ /* get out from reset state */
+ hi843x_writeb(priv, HI843X_CTRL_REG, 0);
+ }
+
+ ret = iio_triggered_buffer_setup(idev, NULL, hi843x_trigger_handler,
+ &hi843x_buffer_setup_ops);
+ if (ret)
+ return ret;
+
+ ret = iio_device_register(idev);
+ if (ret < 0) {
+ dev_err(&spi->dev, "unable to register device\n");
+ goto unregister_buffer;
+ }
+
+ return 0;
+
+unregister_buffer:
+ iio_triggered_buffer_cleanup(idev);
+ return ret;
+}
+
+static int hi843x_remove(struct spi_device *spi)
+{
+ struct iio_dev *idev = spi_get_drvdata(spi);
+ struct hi843x_priv *priv = iio_priv(idev);
+
+ cancel_delayed_work_sync(&priv->work);
+ iio_device_unregister(idev);
+ iio_triggered_buffer_cleanup(idev);
+
+ return 0;
+}
+
+static const struct of_device_id hi843x_dt_ids[] = {
+ { .compatible = "holt,hi-8435" },
+ { .compatible = "holt,hi-8436" },
+ { .compatible = "holt,hi-8437" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, hi843x_dt_ids);
+
+static const struct spi_device_id hi843x_id[] = {
+ { "hi-8435", 0},
+ { "hi-8436", 0},
+ { "hi-8437", 0},
+ { }
+};
+MODULE_DEVICE_TABLE(spi, hi843x_id);
+
+static struct spi_driver hi843x_driver = {
+ .driver = {
+ .name = DRV_NAME,
+ .of_match_table = of_match_ptr(hi843x_dt_ids),
+ },
+ .probe = hi843x_probe,
+ .remove = hi843x_remove,
+ .id_table = hi843x_id,
+};
+module_spi_driver(hi843x_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Vladimir Barinov");
+MODULE_DESCRIPTION("HI-8435/8436/8437 discrete ADC");
--
1.9.1

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