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Message-ID: <alpine.DEB.2.02.1607190026540.25263@pmeerw.net>
Date: Tue, 19 Jul 2016 00:38:21 +0200 (CEST)
From: Peter Meerwald-Stadler <pmeerw@...erw.net>
To: William Breathitt Gray <vilhelm.gray@...il.com>
cc: jic23@...nel.org, knaack.h@....de, lars@...afoo.de,
linux-iio@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/2] iio: stx104: Move the STX104 IIO driver to the ADC
directory
On Mon, 18 Jul 2016, William Breathitt Gray wrote:
> The Apex Embedded Systems STX104 is primarily an analog-to-digital
> converter device. The STX104 IIO driver was initially placed in the DAC
> directory because only the DAC portion of the STX104 was supported at
> the time. Now that ADC support has been added to the STX104 IIO driver,
> the driver should be moved to the more appropriate ADC directory.
minor comments below (the full code is easier to read, so commenting here)
> Signed-off-by: William Breathitt Gray <vilhelm.gray@...il.com>
> ---
> MAINTAINERS | 2 +-
> drivers/iio/adc/Kconfig | 9 ++
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/stx104.c | 371 +++++++++++++++++++++++++++++++++++++++++++++++
> drivers/iio/dac/Kconfig | 9 --
> drivers/iio/dac/Makefile | 1 -
> drivers/iio/dac/stx104.c | 371 -----------------------------------------------
> 7 files changed, 382 insertions(+), 382 deletions(-)
> create mode 100644 drivers/iio/adc/stx104.c
> delete mode 100644 drivers/iio/dac/stx104.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 345e757..95dd91b 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -796,7 +796,7 @@ APEX EMBEDDED SYSTEMS STX104 DAC DRIVER
> M: William Breathitt Gray <vilhelm.gray@...il.com>
> L: linux-iio@...r.kernel.org
> S: Maintained
> -F: drivers/iio/dac/stx104.c
> +F: drivers/iio/adc/stx104.c
>
> APM DRIVER
> M: Jiri Kosina <jikos@...nel.org>
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 1de31bd..62521f3 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -396,6 +396,15 @@ config ROCKCHIP_SARADC
> To compile this driver as a module, choose M here: the
> module will be called rockchip_saradc.
>
> +config STX104
> + tristate "Apex Embedded Systems STX104 driver"
> + depends on X86 && ISA_BUS_API
> + select GPIOLIB
> + help
> + Say yes here to build support for the Apex Embedded Systems STX104
> + integrated analog PC/104 card. The base port addresses for the devices
> + may be configured via the base array module parameter.
> +
> config TI_ADC081C
> tristate "Texas Instruments ADC081C/ADC101C/ADC121C family"
> depends on I2C
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index 0ba0d50..d7b4a71 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -38,6 +38,7 @@ obj-$(CONFIG_PALMAS_GPADC) += palmas_gpadc.o
> obj-$(CONFIG_QCOM_SPMI_IADC) += qcom-spmi-iadc.o
> obj-$(CONFIG_QCOM_SPMI_VADC) += qcom-spmi-vadc.o
> obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o
> +obj-$(CONFIG_STX104) += stx104.o
> obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o
> obj-$(CONFIG_TI_ADC0832) += ti-adc0832.o
> obj-$(CONFIG_TI_ADC128S052) += ti-adc128s052.o
> diff --git a/drivers/iio/adc/stx104.c b/drivers/iio/adc/stx104.c
> new file mode 100644
> index 0000000..4b59721
> --- /dev/null
> +++ b/drivers/iio/adc/stx104.c
> @@ -0,0 +1,371 @@
> +/*
> + * 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/module.h>
> +#include <linux/moduleparam.h>
> +#include <linux/spinlock.h>
> +
> +#define STX104_EXTENT 16
> +
> +#define STX104_OUT_CHAN(chan) { \
> + .type = IIO_VOLTAGE, \
> + .channel = chan, \
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
> + .indexed = 1, \
> + .output = 1 \
> +}
> +#define STX104_GAIN_CHAN { \
> + .type = IIO_VOLTAGE, \
> + .info_mask_separate = BIT(IIO_CHAN_INFO_HARDWAREGAIN), \
> + .output = 1 \
> +}
> +#define STX104_IN_CHAN(chan) { \
> + .type = IIO_VOLTAGE, \
> + .channel = chan, \
> + .info_mask_separate = BIT(IIO_CHAN_INFO_SCALE), \
shouldn't this be _RAW? I'm confused
> + .indexed = 1 \
> +}
> +
> +#define STX104_NUM_OUT_CHAN 2
> +#define STX104_NUM_GAIN_CHAN 1
> +#define STX104_NUM_IN_CHAN 16
> +#define IN_CHAN_OFFSET (STX104_NUM_OUT_CHAN + STX104_NUM_GAIN_CHAN)
prefix required
> +#define STX104_MAX_NUM_CHAN (IN_CHAN_OFFSET + STX104_NUM_IN_CHAN)
do we really need MAX_NUM_CHAN?
> +
> +static unsigned int base[max_num_isa_dev(STX104_EXTENT)];
> +static unsigned int num_stx104;
> +module_param_array(base, uint, &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);
> + long adc_sample;
> + unsigned int adc_config;
> + long adbu;
> + unsigned int gain;
> +
> + /* handle output channels */
> + if (chan->output) {
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + *val = priv->chan_out_states[chan->channel];
> + return IIO_VAL_INT;
> + case IIO_CHAN_INFO_HARDWAREGAIN:
> + *val = 1 << (inb(priv->base + 11) & 0x3);
> + return IIO_VAL_INT;
> + default:
> + return -EINVAL;
> + }
> + }
> +
> + if (mask != IIO_CHAN_INFO_SCALE)
> + return -EINVAL;
> +
> + /* select ADC channel */
> + outb(chan->channel | (chan->channel << 4), priv->base + 2);
> +
> + /* trigger ADC sample capture and wait for completion*/
add whitespace before */
> + outb(0, priv->base);
> + while (inb(priv->base + 8) & BIT(7));
> +
> + adc_sample = inw(priv->base);
> +
> + /* get ADC bipolar/unipolar and gain configuration */
> + adc_config = inb(priv->base + 11);
> + adbu = !(adc_config & BIT(2));
> + gain = adc_config & 0x3;
> +
> + /* Value conversion math:
> + * ----------------------
> + * scale = adc_sample / 65536
> + * range = 10 / (1 << gain)
> + * voltage = scale * (range + adbu * range) - adbu * range
> + *
> + * Simplified:
> + * -----------
> + * voltage = 5 * (adc_sample * (1 + adbu) - adbu * 65536) /
> + * (1 << (15 + gain))
> + *
> + * Portability Caution:
> + * --------------------
> + * *val will be set to a value between -327680 and 327675; in order to
> + * prevent integer underflow/overflow, the int data type of the
> + * implementation should be capable of representing this value range.
> + */
> + *val = 5 * (adc_sample * (1 + adbu) - adbu * 65536);
> + *val2 = 15 + gain;
> +
> + return IIO_VAL_FRACTIONAL_LOG2;
> +}
> +
> +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_RAW:
> + /* 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;
here would be clearer IMHO
> + break;
> + 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;
> + }
> +
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> +static const struct iio_info stx104_info = {
> + .driver_module = THIS_MODULE,
> + .read_raw = stx104_read_raw,
> + .write_raw = stx104_write_raw
maybe end with ,
> +};
> +
> +static struct iio_chan_spec stx104_channels[STX104_MAX_NUM_CHAN] = {
I'd put a note stating that chan_spec is modified lateron, hence NOT const
> + STX104_OUT_CHAN(0), STX104_OUT_CHAN(1),
> + STX104_GAIN_CHAN,
> + STX104_IN_CHAN(0), STX104_IN_CHAN(1), STX104_IN_CHAN(2),
> + STX104_IN_CHAN(3), STX104_IN_CHAN(4), STX104_IN_CHAN(5),
> + STX104_IN_CHAN(6), STX104_IN_CHAN(7), STX104_IN_CHAN(8),
> + STX104_IN_CHAN(9), STX104_IN_CHAN(10), STX104_IN_CHAN(11),
> + STX104_IN_CHAN(12), STX104_IN_CHAN(13), STX104_IN_CHAN(14),
> + STX104_IN_CHAN(15)
> +};
> +
> +static int stx104_gpio_get_direction(struct gpio_chip *chip,
> + unsigned int offset)
> +{
> + if (offset < 4)
what is 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 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);
> +}
> +
> +static int stx104_probe(struct device *dev, unsigned int id)
> +{
> + struct iio_dev *indio_dev;
> + struct stx104_iio *priv;
> + struct stx104_gpio *stx104gpio;
> + int i;
> + 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;
> + indio_dev->num_channels = IN_CHAN_OFFSET + STX104_NUM_IN_CHAN;
ARRAY_SIZE()
> +
> + /* determine if differential inputs */
> + if (inb(base[id] + 8) & BIT(5)) {
> + indio_dev->num_channels -= STX104_NUM_IN_CHAN / 2;
> +
> + for (i = 0; i < STX104_NUM_IN_CHAN / 2; i++) {
> + stx104_channels[i + IN_CHAN_OFFSET].differential = 1;
> + stx104_channels[i + IN_CHAN_OFFSET].channel2 = i;
> + }
> + }
> +
> + indio_dev->channels = stx104_channels;
> + indio_dev->name = dev_name(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);
> +
> + err = devm_iio_device_register(dev, indio_dev);
shouldn't use devm_ if stuff is done in _remove()
> + if (err) {
> + dev_err(dev, "IIO device registering failed (%d)\n", err);
> + return err;
> + }
> +
> + stx104gpio->chip.label = dev_name(dev);
> + stx104gpio->chip.parent = dev;
> + stx104gpio->chip.owner = THIS_MODULE;
> + stx104gpio->chip.base = -1;
> + stx104gpio->chip.ngpio = 8;
> + 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.set = stx104_gpio_set;
> + stx104gpio->base = base[id] + 3;
> + stx104gpio->out_state = 0x0;
> +
> + spin_lock_init(&stx104gpio->lock);
> +
> + dev_set_drvdata(dev, stx104gpio);
> +
> + err = gpiochip_add_data(&stx104gpio->chip, stx104gpio);
> + if (err) {
need to iio_device_unregister()
I'd move the gpio stuff BEFORE iio_device_register(), to avoid a potential
race window
> + dev_err(dev, "GPIO registering failed (%d)\n", err);
> + return err;
> + }
> +
> + return 0;
> +}
> +
> +static int stx104_remove(struct device *dev, unsigned int id)
> +{
> + struct stx104_gpio *const stx104gpio = dev_get_drvdata(dev);
> +
> + gpiochip_remove(&stx104gpio->chip);
> +
> + return 0;
> +}
> +
> +static struct isa_driver stx104_driver = {
> + .probe = stx104_probe,
> + .driver = {
> + .name = "stx104"
> + },
> + .remove = stx104_remove
> +};
> +
> +module_isa_driver(stx104_driver, num_stx104);
> +
> +MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@...il.com>");
> +MODULE_DESCRIPTION("Apex Embedded Systems STX104 IIO driver");
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
> index f7f896e..d359fef 100644
> --- a/drivers/iio/dac/Kconfig
> +++ b/drivers/iio/dac/Kconfig
> @@ -245,15 +245,6 @@ config MCP4922
> To compile this driver as a module, choose M here: the module
> will be called mcp4922.
>
> -config STX104
> - tristate "Apex Embedded Systems STX104 driver"
> - depends on X86 && ISA_BUS_API
> - select GPIOLIB
> - help
> - Say yes here to build support for the Apex Embedded Systems STX104
> - integrated analog PC/104 card. The base port addresses for the devices
> - may be configured via the base array module parameter.
> -
> config VF610_DAC
> tristate "Vybrid vf610 DAC driver"
> depends on OF
> diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
> index 8b78d5c..7acb05d 100644
> --- a/drivers/iio/dac/Makefile
> +++ b/drivers/iio/dac/Makefile
> @@ -26,5 +26,4 @@ obj-$(CONFIG_MAX517) += max517.o
> obj-$(CONFIG_MAX5821) += max5821.o
> obj-$(CONFIG_MCP4725) += mcp4725.o
> obj-$(CONFIG_MCP4922) += mcp4922.o
> -obj-$(CONFIG_STX104) += stx104.o
> obj-$(CONFIG_VF610_DAC) += vf610_dac.o
> diff --git a/drivers/iio/dac/stx104.c b/drivers/iio/dac/stx104.c
> deleted file mode 100644
> index 4986e9a..0000000
> --- a/drivers/iio/dac/stx104.c
> +++ /dev/null
> @@ -1,371 +0,0 @@
> -/*
> - * 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/module.h>
> -#include <linux/moduleparam.h>
> -#include <linux/spinlock.h>
> -
> -#define STX104_EXTENT 16
> -
> -#define STX104_OUT_CHAN(chan) { \
> - .type = IIO_VOLTAGE, \
> - .channel = chan, \
> - .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
> - .indexed = 1, \
> - .output = 1 \
> -}
> -#define STX104_GAIN_CHAN { \
> - .type = IIO_VOLTAGE, \
> - .info_mask_separate = BIT(IIO_CHAN_INFO_HARDWAREGAIN), \
> - .output = 1 \
> -}
> -#define STX104_IN_CHAN(chan) { \
> - .type = IIO_VOLTAGE, \
> - .channel = chan, \
> - .info_mask_separate = BIT(IIO_CHAN_INFO_SCALE), \
> - .indexed = 1 \
> -}
> -
> -#define STX104_NUM_OUT_CHAN 2
> -#define STX104_NUM_GAIN_CHAN 1
> -#define STX104_NUM_IN_CHAN 16
> -#define IN_CHAN_OFFSET (STX104_NUM_OUT_CHAN + STX104_NUM_GAIN_CHAN)
> -#define STX104_MAX_NUM_CHAN (IN_CHAN_OFFSET + STX104_NUM_IN_CHAN)
> -
> -static unsigned int base[max_num_isa_dev(STX104_EXTENT)];
> -static unsigned int num_stx104;
> -module_param_array(base, uint, &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 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);
> - long adc_sample;
> - unsigned int adc_config;
> - long adbu;
> - unsigned int gain;
> -
> - /* handle output channels */
> - if (chan->output) {
> - switch (mask) {
> - case IIO_CHAN_INFO_RAW:
> - *val = priv->chan_out_states[chan->channel];
> - return IIO_VAL_INT;
> - case IIO_CHAN_INFO_HARDWAREGAIN:
> - *val = 1 << (inb(priv->base + 11) & 0x3);
> - return IIO_VAL_INT;
> - default:
> - return -EINVAL;
> - }
> - }
> -
> - if (mask != IIO_CHAN_INFO_SCALE)
> - return -EINVAL;
> -
> - /* 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));
> -
> - adc_sample = inw(priv->base);
> -
> - /* get ADC bipolar/unipolar and gain configuration */
> - adc_config = inb(priv->base + 11);
> - adbu = !(adc_config & BIT(2));
> - gain = adc_config & 0x3;
> -
> - /* Value conversion math:
> - * ----------------------
> - * scale = adc_sample / 65536
> - * range = 10 / (1 << gain)
> - * voltage = scale * (range + adbu * range) - adbu * range
> - *
> - * Simplified:
> - * -----------
> - * voltage = 5 * (adc_sample * (1 + adbu) - adbu * 65536) /
> - * (1 << (15 + gain))
> - *
> - * Portability Caution:
> - * --------------------
> - * *val will be set to a value between -327680 and 327675; in order to
> - * prevent integer underflow/overflow, the int data type of the
> - * implementation should be capable of representing this value range.
> - */
> - *val = 5 * (adc_sample * (1 + adbu) - adbu * 65536);
> - *val2 = 15 + gain;
> -
> - return IIO_VAL_FRACTIONAL_LOG2;
> -}
> -
> -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_RAW:
> - /* 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);
> -
> - break;
> - 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;
> - }
> -
> - break;
> - default:
> - return -EINVAL;
> - }
> -
> - return 0;
> -}
> -
> -static const struct iio_info stx104_info = {
> - .driver_module = THIS_MODULE,
> - .read_raw = stx104_read_raw,
> - .write_raw = stx104_write_raw
> -};
> -
> -static struct iio_chan_spec stx104_channels[STX104_MAX_NUM_CHAN] = {
> - STX104_OUT_CHAN(0), STX104_OUT_CHAN(1),
> - STX104_GAIN_CHAN,
> - STX104_IN_CHAN(0), STX104_IN_CHAN(1), STX104_IN_CHAN(2),
> - STX104_IN_CHAN(3), STX104_IN_CHAN(4), STX104_IN_CHAN(5),
> - STX104_IN_CHAN(6), STX104_IN_CHAN(7), STX104_IN_CHAN(8),
> - STX104_IN_CHAN(9), STX104_IN_CHAN(10), STX104_IN_CHAN(11),
> - STX104_IN_CHAN(12), STX104_IN_CHAN(13), STX104_IN_CHAN(14),
> - STX104_IN_CHAN(15)
> -};
> -
> -static int stx104_gpio_get_direction(struct gpio_chip *chip,
> - unsigned int offset)
> -{
> - 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 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);
> -}
> -
> -static int stx104_probe(struct device *dev, unsigned int id)
> -{
> - struct iio_dev *indio_dev;
> - struct stx104_iio *priv;
> - struct stx104_gpio *stx104gpio;
> - int i;
> - 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;
> - indio_dev->num_channels = IN_CHAN_OFFSET + STX104_NUM_IN_CHAN;
> -
> - /* determine if differential inputs */
> - if (inb(base[id] + 8) & BIT(5)) {
> - indio_dev->num_channels -= STX104_NUM_IN_CHAN / 2;
> -
> - for (i = 0; i < STX104_NUM_IN_CHAN / 2; i++) {
> - stx104_channels[i + IN_CHAN_OFFSET].differential = 1;
> - stx104_channels[i + IN_CHAN_OFFSET].channel2 = i;
> - }
> - }
> -
> - indio_dev->channels = stx104_channels;
> - indio_dev->name = dev_name(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);
> -
> - err = devm_iio_device_register(dev, indio_dev);
> - if (err) {
> - dev_err(dev, "IIO device registering failed (%d)\n", err);
> - return err;
> - }
> -
> - stx104gpio->chip.label = dev_name(dev);
> - stx104gpio->chip.parent = dev;
> - stx104gpio->chip.owner = THIS_MODULE;
> - stx104gpio->chip.base = -1;
> - stx104gpio->chip.ngpio = 8;
> - 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.set = stx104_gpio_set;
> - stx104gpio->base = base[id] + 3;
> - stx104gpio->out_state = 0x0;
> -
> - spin_lock_init(&stx104gpio->lock);
> -
> - dev_set_drvdata(dev, stx104gpio);
> -
> - err = gpiochip_add_data(&stx104gpio->chip, stx104gpio);
> - if (err) {
> - dev_err(dev, "GPIO registering failed (%d)\n", err);
> - return err;
> - }
> -
> - return 0;
> -}
> -
> -static int stx104_remove(struct device *dev, unsigned int id)
> -{
> - struct stx104_gpio *const stx104gpio = dev_get_drvdata(dev);
> -
> - gpiochip_remove(&stx104gpio->chip);
> -
> - return 0;
> -}
> -
> -static struct isa_driver stx104_driver = {
> - .probe = stx104_probe,
> - .driver = {
> - .name = "stx104"
> - },
> - .remove = stx104_remove
> -};
> -
> -module_isa_driver(stx104_driver, num_stx104);
> -
> -MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@...il.com>");
> -MODULE_DESCRIPTION("Apex Embedded Systems STX104 IIO driver");
> -MODULE_LICENSE("GPL v2");
>
--
Peter Meerwald-Stadler
+43-664-2444418 (mobile)
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