Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 383 insertions, 0 deletions

diff --git a/drivers/iio/adc/stx104.c b/drivers/iio/adc/stx104.c
new file mode 100644
index 000000000..0662ca199
--- /dev/null
+++ b/drivers/iio/adc/stx104.c
@@ -0,0 +1,383 @@
+/*
+ * IIO driver for the Apex Embedded Systems STX104
+ * Copyright (C) 2016 William Breathitt Gray
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * 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/bitops.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/gpio/driver.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/types.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/isa.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/spinlock.h>
+
+#define STX104_OUT_CHAN(chan) {				\
+	.type = IIO_VOLTAGE,				\
+	.channel = chan,				\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
+	.indexed = 1,					\
+	.output = 1					\
+}
+#define STX104_IN_CHAN(chan, diff) {					\
+	.type = IIO_VOLTAGE,						\
+	.channel = chan,						\
+	.channel2 = chan,						\
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_HARDWAREGAIN) |	\
+		BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_SCALE),	\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),			\
+	.indexed = 1,							\
+	.differential = diff						\
+}
+
+#define STX104_NUM_OUT_CHAN 2
+
+#define STX104_EXTENT 16
+
+static unsigned int base[max_num_isa_dev(STX104_EXTENT)];
+static unsigned int num_stx104;
+module_param_hw_array(base, uint, ioport, &num_stx104, 0);
+MODULE_PARM_DESC(base, "Apex Embedded Systems STX104 base addresses");
+
+/**
+ * struct stx104_iio - IIO device private data structure
+ * @chan_out_states:	channels' output states
+ * @base:		base port address of the IIO device
+ */
+struct stx104_iio {
+	unsigned int chan_out_states[STX104_NUM_OUT_CHAN];
+	unsigned int base;
+};
+
+/**
+ * struct stx104_gpio - GPIO device private data structure
+ * @chip:	instance of the gpio_chip
+ * @lock:	synchronization lock to prevent I/O race conditions
+ * @base:	base port address of the GPIO device
+ * @out_state:	output bits state
+ */
+struct stx104_gpio {
+	struct gpio_chip chip;
+	spinlock_t lock;
+	unsigned int base;
+	unsigned int out_state;
+};
+
+static int stx104_read_raw(struct iio_dev *indio_dev,
+	struct iio_chan_spec const *chan, int *val, int *val2, long mask)
+{
+	struct stx104_iio *const priv = iio_priv(indio_dev);
+	unsigned int adc_config;
+	int adbu;
+	int gain;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		/* get gain configuration */
+		adc_config = inb(priv->base + 11);
+		gain = adc_config & 0x3;
+
+		*val = 1 << gain;
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_RAW:
+		if (chan->output) {
+			*val = priv->chan_out_states[chan->channel];
+			return IIO_VAL_INT;
+		}
+
+		/* select ADC channel */
+		outb(chan->channel | (chan->channel << 4), priv->base + 2);
+
+		/* trigger ADC sample capture and wait for completion */
+		outb(0, priv->base);
+		while (inb(priv->base + 8) & BIT(7));
+
+		*val = inw(priv->base);
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_OFFSET:
+		/* get ADC bipolar/unipolar configuration */
+		adc_config = inb(priv->base + 11);
+		adbu = !(adc_config & BIT(2));
+
+		*val = -32768 * adbu;
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		/* get ADC bipolar/unipolar and gain configuration */
+		adc_config = inb(priv->base + 11);
+		adbu = !(adc_config & BIT(2));
+		gain = adc_config & 0x3;
+
+		*val = 5;
+		*val2 = 15 - adbu + gain;
+		return IIO_VAL_FRACTIONAL_LOG2;
+	}
+
+	return -EINVAL;
+}
+
+static int stx104_write_raw(struct iio_dev *indio_dev,
+	struct iio_chan_spec const *chan, int val, int val2, long mask)
+{
+	struct stx104_iio *const priv = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		/* Only four gain states (x1, x2, x4, x8) */
+		switch (val) {
+		case 1:
+			outb(0, priv->base + 11);
+			break;
+		case 2:
+			outb(1, priv->base + 11);
+			break;
+		case 4:
+			outb(2, priv->base + 11);
+			break;
+		case 8:
+			outb(3, priv->base + 11);
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		return 0;
+	case IIO_CHAN_INFO_RAW:
+		if (chan->output) {
+			/* DAC can only accept up to a 16-bit value */
+			if ((unsigned int)val > 65535)
+				return -EINVAL;
+
+			priv->chan_out_states[chan->channel] = val;
+			outw(val, priv->base + 4 + 2 * chan->channel);
+
+			return 0;
+		}
+		return -EINVAL;
+	}
+
+	return -EINVAL;
+}
+
+static const struct iio_info stx104_info = {
+	.read_raw = stx104_read_raw,
+	.write_raw = stx104_write_raw
+};
+
+/* single-ended input channels configuration */
+static const struct iio_chan_spec stx104_channels_sing[] = {
+	STX104_OUT_CHAN(0), STX104_OUT_CHAN(1),
+	STX104_IN_CHAN(0, 0), STX104_IN_CHAN(1, 0), STX104_IN_CHAN(2, 0),
+	STX104_IN_CHAN(3, 0), STX104_IN_CHAN(4, 0), STX104_IN_CHAN(5, 0),
+	STX104_IN_CHAN(6, 0), STX104_IN_CHAN(7, 0), STX104_IN_CHAN(8, 0),
+	STX104_IN_CHAN(9, 0), STX104_IN_CHAN(10, 0), STX104_IN_CHAN(11, 0),
+	STX104_IN_CHAN(12, 0), STX104_IN_CHAN(13, 0), STX104_IN_CHAN(14, 0),
+	STX104_IN_CHAN(15, 0)
+};
+/* differential input channels configuration */
+static const struct iio_chan_spec stx104_channels_diff[] = {
+	STX104_OUT_CHAN(0), STX104_OUT_CHAN(1),
+	STX104_IN_CHAN(0, 1), STX104_IN_CHAN(1, 1), STX104_IN_CHAN(2, 1),
+	STX104_IN_CHAN(3, 1), STX104_IN_CHAN(4, 1), STX104_IN_CHAN(5, 1),
+	STX104_IN_CHAN(6, 1), STX104_IN_CHAN(7, 1)
+};
+
+static int stx104_gpio_get_direction(struct gpio_chip *chip,
+	unsigned int offset)
+{
+	/* GPIO 0-3 are input only, while the rest are output only */
+	if (offset < 4)
+		return 1;
+
+	return 0;
+}
+
+static int stx104_gpio_direction_input(struct gpio_chip *chip,
+	unsigned int offset)
+{
+	if (offset >= 4)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int stx104_gpio_direction_output(struct gpio_chip *chip,
+	unsigned int offset, int value)
+{
+	if (offset < 4)
+		return -EINVAL;
+
+	chip->set(chip, offset, value);
+	return 0;
+}
+
+static int stx104_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+	struct stx104_gpio *const stx104gpio = gpiochip_get_data(chip);
+
+	if (offset >= 4)
+		return -EINVAL;
+
+	return !!(inb(stx104gpio->base) & BIT(offset));
+}
+
+static int stx104_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
+	unsigned long *bits)
+{
+	struct stx104_gpio *const stx104gpio = gpiochip_get_data(chip);
+
+	*bits = inb(stx104gpio->base);
+
+	return 0;
+}
+
+static void stx104_gpio_set(struct gpio_chip *chip, unsigned int offset,
+	int value)
+{
+	struct stx104_gpio *const stx104gpio = gpiochip_get_data(chip);
+	const unsigned int mask = BIT(offset) >> 4;
+	unsigned long flags;
+
+	if (offset < 4)
+		return;
+
+	spin_lock_irqsave(&stx104gpio->lock, flags);
+
+	if (value)
+		stx104gpio->out_state |= mask;
+	else
+		stx104gpio->out_state &= ~mask;
+
+	outb(stx104gpio->out_state, stx104gpio->base);
+
+	spin_unlock_irqrestore(&stx104gpio->lock, flags);
+}
+
+#define STX104_NGPIO 8
+static const char *stx104_names[STX104_NGPIO] = {
+	"DIN0", "DIN1", "DIN2", "DIN3", "DOUT0", "DOUT1", "DOUT2", "DOUT3"
+};
+
+static void stx104_gpio_set_multiple(struct gpio_chip *chip,
+	unsigned long *mask, unsigned long *bits)
+{
+	struct stx104_gpio *const stx104gpio = gpiochip_get_data(chip);
+	unsigned long flags;
+
+	/* verify masked GPIO are output */
+	if (!(*mask & 0xF0))
+		return;
+
+	*mask >>= 4;
+	*bits >>= 4;
+
+	spin_lock_irqsave(&stx104gpio->lock, flags);
+
+	stx104gpio->out_state &= ~*mask;
+	stx104gpio->out_state |= *mask & *bits;
+	outb(stx104gpio->out_state, stx104gpio->base);
+
+	spin_unlock_irqrestore(&stx104gpio->lock, flags);
+}
+
+static int stx104_probe(struct device *dev, unsigned int id)
+{
+	struct iio_dev *indio_dev;
+	struct stx104_iio *priv;
+	struct stx104_gpio *stx104gpio;
+	int err;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*priv));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	stx104gpio = devm_kzalloc(dev, sizeof(*stx104gpio), GFP_KERNEL);
+	if (!stx104gpio)
+		return -ENOMEM;
+
+	if (!devm_request_region(dev, base[id], STX104_EXTENT,
+		dev_name(dev))) {
+		dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
+			base[id], base[id] + STX104_EXTENT);
+		return -EBUSY;
+	}
+
+	indio_dev->info = &stx104_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	/* determine if differential inputs */
+	if (inb(base[id] + 8) & BIT(5)) {
+		indio_dev->num_channels = ARRAY_SIZE(stx104_channels_diff);
+		indio_dev->channels = stx104_channels_diff;
+	} else {
+		indio_dev->num_channels = ARRAY_SIZE(stx104_channels_sing);
+		indio_dev->channels = stx104_channels_sing;
+	}
+
+	indio_dev->name = dev_name(dev);
+	indio_dev->dev.parent = dev;
+
+	priv = iio_priv(indio_dev);
+	priv->base = base[id];
+
+	/* configure device for software trigger operation */
+	outb(0, base[id] + 9);
+
+	/* initialize gain setting to x1 */
+	outb(0, base[id] + 11);
+
+	/* initialize DAC output to 0V */
+	outw(0, base[id] + 4);
+	outw(0, base[id] + 6);
+
+	stx104gpio->chip.label = dev_name(dev);
+	stx104gpio->chip.parent = dev;
+	stx104gpio->chip.owner = THIS_MODULE;
+	stx104gpio->chip.base = -1;
+	stx104gpio->chip.ngpio = STX104_NGPIO;
+	stx104gpio->chip.names = stx104_names;
+	stx104gpio->chip.get_direction = stx104_gpio_get_direction;
+	stx104gpio->chip.direction_input = stx104_gpio_direction_input;
+	stx104gpio->chip.direction_output = stx104_gpio_direction_output;
+	stx104gpio->chip.get = stx104_gpio_get;
+	stx104gpio->chip.get_multiple = stx104_gpio_get_multiple;
+	stx104gpio->chip.set = stx104_gpio_set;
+	stx104gpio->chip.set_multiple = stx104_gpio_set_multiple;
+	stx104gpio->base = base[id] + 3;
+	stx104gpio->out_state = 0x0;
+
+	spin_lock_init(&stx104gpio->lock);
+
+	err = devm_gpiochip_add_data(dev, &stx104gpio->chip, stx104gpio);
+	if (err) {
+		dev_err(dev, "GPIO registering failed (%d)\n", err);
+		return err;
+	}
+
+	return devm_iio_device_register(dev, indio_dev);
+}
+
+static struct isa_driver stx104_driver = {
+	.probe = stx104_probe,
+	.driver = {
+		.name = "stx104"
+	},
+};
+
+module_isa_driver(stx104_driver, num_stx104);
+
+MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
+MODULE_DESCRIPTION("Apex Embedded Systems STX104 IIO driver");
+MODULE_LICENSE("GPL v2");