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374 lines
9.3 KiB
374 lines
9.3 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* IIO driver for the Apex Embedded Systems STX104 |
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* Copyright (C) 2016 William Breathitt Gray |
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*/ |
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#include <linux/bitops.h> |
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#include <linux/device.h> |
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#include <linux/errno.h> |
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#include <linux/gpio/driver.h> |
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#include <linux/iio/iio.h> |
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#include <linux/iio/types.h> |
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#include <linux/io.h> |
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#include <linux/ioport.h> |
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#include <linux/isa.h> |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/moduleparam.h> |
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#include <linux/spinlock.h> |
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#define STX104_OUT_CHAN(chan) { \ |
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.type = IIO_VOLTAGE, \ |
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.channel = chan, \ |
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ |
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.indexed = 1, \ |
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.output = 1 \ |
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} |
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#define STX104_IN_CHAN(chan, diff) { \ |
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.type = IIO_VOLTAGE, \ |
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.channel = chan, \ |
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.channel2 = chan, \ |
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_HARDWAREGAIN) | \ |
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BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_SCALE), \ |
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ |
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.indexed = 1, \ |
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.differential = diff \ |
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} |
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#define STX104_NUM_OUT_CHAN 2 |
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#define STX104_EXTENT 16 |
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static unsigned int base[max_num_isa_dev(STX104_EXTENT)]; |
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static unsigned int num_stx104; |
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module_param_hw_array(base, uint, ioport, &num_stx104, 0); |
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MODULE_PARM_DESC(base, "Apex Embedded Systems STX104 base addresses"); |
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/** |
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* struct stx104_iio - IIO device private data structure |
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* @chan_out_states: channels' output states |
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* @base: base port address of the IIO device |
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*/ |
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struct stx104_iio { |
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unsigned int chan_out_states[STX104_NUM_OUT_CHAN]; |
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unsigned int base; |
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}; |
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/** |
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* struct stx104_gpio - GPIO device private data structure |
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* @chip: instance of the gpio_chip |
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* @lock: synchronization lock to prevent I/O race conditions |
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* @base: base port address of the GPIO device |
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* @out_state: output bits state |
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*/ |
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struct stx104_gpio { |
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struct gpio_chip chip; |
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spinlock_t lock; |
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unsigned int base; |
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unsigned int out_state; |
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}; |
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static int stx104_read_raw(struct iio_dev *indio_dev, |
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struct iio_chan_spec const *chan, int *val, int *val2, long mask) |
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{ |
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struct stx104_iio *const priv = iio_priv(indio_dev); |
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unsigned int adc_config; |
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int adbu; |
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int gain; |
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switch (mask) { |
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case IIO_CHAN_INFO_HARDWAREGAIN: |
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/* get gain configuration */ |
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adc_config = inb(priv->base + 11); |
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gain = adc_config & 0x3; |
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*val = 1 << gain; |
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return IIO_VAL_INT; |
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case IIO_CHAN_INFO_RAW: |
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if (chan->output) { |
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*val = priv->chan_out_states[chan->channel]; |
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return IIO_VAL_INT; |
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} |
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/* select ADC channel */ |
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outb(chan->channel | (chan->channel << 4), priv->base + 2); |
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/* trigger ADC sample capture and wait for completion */ |
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outb(0, priv->base); |
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while (inb(priv->base + 8) & BIT(7)); |
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*val = inw(priv->base); |
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return IIO_VAL_INT; |
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case IIO_CHAN_INFO_OFFSET: |
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/* get ADC bipolar/unipolar configuration */ |
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adc_config = inb(priv->base + 11); |
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adbu = !(adc_config & BIT(2)); |
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*val = -32768 * adbu; |
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return IIO_VAL_INT; |
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case IIO_CHAN_INFO_SCALE: |
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/* get ADC bipolar/unipolar and gain configuration */ |
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adc_config = inb(priv->base + 11); |
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adbu = !(adc_config & BIT(2)); |
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gain = adc_config & 0x3; |
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*val = 5; |
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*val2 = 15 - adbu + gain; |
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return IIO_VAL_FRACTIONAL_LOG2; |
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} |
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return -EINVAL; |
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} |
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static int stx104_write_raw(struct iio_dev *indio_dev, |
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struct iio_chan_spec const *chan, int val, int val2, long mask) |
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{ |
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struct stx104_iio *const priv = iio_priv(indio_dev); |
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switch (mask) { |
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case IIO_CHAN_INFO_HARDWAREGAIN: |
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/* Only four gain states (x1, x2, x4, x8) */ |
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switch (val) { |
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case 1: |
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outb(0, priv->base + 11); |
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break; |
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case 2: |
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outb(1, priv->base + 11); |
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break; |
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case 4: |
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outb(2, priv->base + 11); |
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break; |
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case 8: |
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outb(3, priv->base + 11); |
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break; |
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default: |
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return -EINVAL; |
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} |
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return 0; |
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case IIO_CHAN_INFO_RAW: |
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if (chan->output) { |
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/* DAC can only accept up to a 16-bit value */ |
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if ((unsigned int)val > 65535) |
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return -EINVAL; |
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priv->chan_out_states[chan->channel] = val; |
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outw(val, priv->base + 4 + 2 * chan->channel); |
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return 0; |
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} |
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return -EINVAL; |
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} |
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return -EINVAL; |
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} |
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static const struct iio_info stx104_info = { |
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.read_raw = stx104_read_raw, |
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.write_raw = stx104_write_raw |
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}; |
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/* single-ended input channels configuration */ |
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static const struct iio_chan_spec stx104_channels_sing[] = { |
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STX104_OUT_CHAN(0), STX104_OUT_CHAN(1), |
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STX104_IN_CHAN(0, 0), STX104_IN_CHAN(1, 0), STX104_IN_CHAN(2, 0), |
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STX104_IN_CHAN(3, 0), STX104_IN_CHAN(4, 0), STX104_IN_CHAN(5, 0), |
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STX104_IN_CHAN(6, 0), STX104_IN_CHAN(7, 0), STX104_IN_CHAN(8, 0), |
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STX104_IN_CHAN(9, 0), STX104_IN_CHAN(10, 0), STX104_IN_CHAN(11, 0), |
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STX104_IN_CHAN(12, 0), STX104_IN_CHAN(13, 0), STX104_IN_CHAN(14, 0), |
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STX104_IN_CHAN(15, 0) |
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}; |
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/* differential input channels configuration */ |
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static const struct iio_chan_spec stx104_channels_diff[] = { |
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STX104_OUT_CHAN(0), STX104_OUT_CHAN(1), |
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STX104_IN_CHAN(0, 1), STX104_IN_CHAN(1, 1), STX104_IN_CHAN(2, 1), |
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STX104_IN_CHAN(3, 1), STX104_IN_CHAN(4, 1), STX104_IN_CHAN(5, 1), |
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STX104_IN_CHAN(6, 1), STX104_IN_CHAN(7, 1) |
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}; |
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static int stx104_gpio_get_direction(struct gpio_chip *chip, |
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unsigned int offset) |
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{ |
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/* GPIO 0-3 are input only, while the rest are output only */ |
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if (offset < 4) |
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return 1; |
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return 0; |
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} |
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static int stx104_gpio_direction_input(struct gpio_chip *chip, |
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unsigned int offset) |
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{ |
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if (offset >= 4) |
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return -EINVAL; |
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return 0; |
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} |
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static int stx104_gpio_direction_output(struct gpio_chip *chip, |
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unsigned int offset, int value) |
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{ |
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if (offset < 4) |
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return -EINVAL; |
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chip->set(chip, offset, value); |
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return 0; |
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} |
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static int stx104_gpio_get(struct gpio_chip *chip, unsigned int offset) |
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{ |
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struct stx104_gpio *const stx104gpio = gpiochip_get_data(chip); |
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if (offset >= 4) |
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return -EINVAL; |
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return !!(inb(stx104gpio->base) & BIT(offset)); |
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} |
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static int stx104_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask, |
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unsigned long *bits) |
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{ |
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struct stx104_gpio *const stx104gpio = gpiochip_get_data(chip); |
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*bits = inb(stx104gpio->base); |
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return 0; |
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} |
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static void stx104_gpio_set(struct gpio_chip *chip, unsigned int offset, |
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int value) |
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{ |
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struct stx104_gpio *const stx104gpio = gpiochip_get_data(chip); |
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const unsigned int mask = BIT(offset) >> 4; |
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unsigned long flags; |
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if (offset < 4) |
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return; |
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spin_lock_irqsave(&stx104gpio->lock, flags); |
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if (value) |
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stx104gpio->out_state |= mask; |
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else |
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stx104gpio->out_state &= ~mask; |
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outb(stx104gpio->out_state, stx104gpio->base); |
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spin_unlock_irqrestore(&stx104gpio->lock, flags); |
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} |
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#define STX104_NGPIO 8 |
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static const char *stx104_names[STX104_NGPIO] = { |
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"DIN0", "DIN1", "DIN2", "DIN3", "DOUT0", "DOUT1", "DOUT2", "DOUT3" |
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}; |
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static void stx104_gpio_set_multiple(struct gpio_chip *chip, |
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unsigned long *mask, unsigned long *bits) |
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{ |
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struct stx104_gpio *const stx104gpio = gpiochip_get_data(chip); |
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unsigned long flags; |
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/* verify masked GPIO are output */ |
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if (!(*mask & 0xF0)) |
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return; |
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*mask >>= 4; |
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*bits >>= 4; |
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spin_lock_irqsave(&stx104gpio->lock, flags); |
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stx104gpio->out_state &= ~*mask; |
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stx104gpio->out_state |= *mask & *bits; |
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outb(stx104gpio->out_state, stx104gpio->base); |
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spin_unlock_irqrestore(&stx104gpio->lock, flags); |
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} |
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static int stx104_probe(struct device *dev, unsigned int id) |
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{ |
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struct iio_dev *indio_dev; |
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struct stx104_iio *priv; |
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struct stx104_gpio *stx104gpio; |
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int err; |
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indio_dev = devm_iio_device_alloc(dev, sizeof(*priv)); |
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if (!indio_dev) |
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return -ENOMEM; |
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stx104gpio = devm_kzalloc(dev, sizeof(*stx104gpio), GFP_KERNEL); |
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if (!stx104gpio) |
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return -ENOMEM; |
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if (!devm_request_region(dev, base[id], STX104_EXTENT, |
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dev_name(dev))) { |
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dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n", |
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base[id], base[id] + STX104_EXTENT); |
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return -EBUSY; |
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} |
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indio_dev->info = &stx104_info; |
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indio_dev->modes = INDIO_DIRECT_MODE; |
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/* determine if differential inputs */ |
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if (inb(base[id] + 8) & BIT(5)) { |
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indio_dev->num_channels = ARRAY_SIZE(stx104_channels_diff); |
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indio_dev->channels = stx104_channels_diff; |
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} else { |
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indio_dev->num_channels = ARRAY_SIZE(stx104_channels_sing); |
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indio_dev->channels = stx104_channels_sing; |
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} |
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indio_dev->name = dev_name(dev); |
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priv = iio_priv(indio_dev); |
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priv->base = base[id]; |
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/* configure device for software trigger operation */ |
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outb(0, base[id] + 9); |
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/* initialize gain setting to x1 */ |
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outb(0, base[id] + 11); |
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/* initialize DAC output to 0V */ |
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outw(0, base[id] + 4); |
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outw(0, base[id] + 6); |
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stx104gpio->chip.label = dev_name(dev); |
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stx104gpio->chip.parent = dev; |
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stx104gpio->chip.owner = THIS_MODULE; |
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stx104gpio->chip.base = -1; |
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stx104gpio->chip.ngpio = STX104_NGPIO; |
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stx104gpio->chip.names = stx104_names; |
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stx104gpio->chip.get_direction = stx104_gpio_get_direction; |
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stx104gpio->chip.direction_input = stx104_gpio_direction_input; |
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stx104gpio->chip.direction_output = stx104_gpio_direction_output; |
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stx104gpio->chip.get = stx104_gpio_get; |
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stx104gpio->chip.get_multiple = stx104_gpio_get_multiple; |
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stx104gpio->chip.set = stx104_gpio_set; |
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stx104gpio->chip.set_multiple = stx104_gpio_set_multiple; |
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stx104gpio->base = base[id] + 3; |
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stx104gpio->out_state = 0x0; |
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spin_lock_init(&stx104gpio->lock); |
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err = devm_gpiochip_add_data(dev, &stx104gpio->chip, stx104gpio); |
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if (err) { |
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dev_err(dev, "GPIO registering failed (%d)\n", err); |
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return err; |
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} |
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return devm_iio_device_register(dev, indio_dev); |
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} |
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static struct isa_driver stx104_driver = { |
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.probe = stx104_probe, |
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.driver = { |
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.name = "stx104" |
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}, |
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}; |
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module_isa_driver(stx104_driver, num_stx104); |
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MODULE_AUTHOR("William Breathitt Gray <[email protected]>"); |
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MODULE_DESCRIPTION("Apex Embedded Systems STX104 IIO driver"); |
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MODULE_LICENSE("GPL v2");
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