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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * IIO driver for the Measurement Computing CIO-DAC4 * Copyright (C) 2016 William Breathitt Gray5 *6 * This driver supports the following Measurement Computing devices: CIO-DAC16,7 * CIO-DAC08, and PC104-DAC06.8 */9#include <linux/bits.h>10#include <linux/device.h>11#include <linux/err.h>12#include <linux/iio/iio.h>13#include <linux/iio/types.h>14#include <linux/isa.h>15#include <linux/module.h>16#include <linux/moduleparam.h>17#include <linux/regmap.h>18#include <linux/types.h>19 20#define CIO_DAC_NUM_CHAN 1621 22#define CIO_DAC_CHAN(chan) { \23 .type = IIO_VOLTAGE, \24 .channel = chan, \25 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \26 .indexed = 1, \27 .output = 1 \28}29 30#define CIO_DAC_EXTENT 3231 32static unsigned int base[max_num_isa_dev(CIO_DAC_EXTENT)];33static unsigned int num_cio_dac;34module_param_hw_array(base, uint, ioport, &num_cio_dac, 0);35MODULE_PARM_DESC(base, "Measurement Computing CIO-DAC base addresses");36 37#define CIO_DAC_BASE 0x0038#define CIO_DAC_CHANNEL_STRIDE 239 40static bool cio_dac_precious_reg(struct device *dev, unsigned int reg)41{42 /*43 * All registers are considered precious; if the XFER jumper is set on44 * the device, then no update occurs until a DAC register is read.45 */46 return true;47}48 49static const struct regmap_config cio_dac_regmap_config = {50 .reg_bits = 16,51 .reg_stride = 2,52 .val_bits = 16,53 .io_port = true,54 .max_register = 0x1F,55 .precious_reg = cio_dac_precious_reg,56};57 58/**59 * struct cio_dac_iio - IIO device private data structure60 * @map: Regmap for the device61 */62struct cio_dac_iio {63 struct regmap *map;64};65 66static int cio_dac_read_raw(struct iio_dev *indio_dev,67 struct iio_chan_spec const *chan, int *val, int *val2, long mask)68{69 struct cio_dac_iio *const priv = iio_priv(indio_dev);70 const unsigned int offset = chan->channel * CIO_DAC_CHANNEL_STRIDE;71 int err;72 unsigned int dac_val;73 74 if (mask != IIO_CHAN_INFO_RAW)75 return -EINVAL;76 77 err = regmap_read(priv->map, CIO_DAC_BASE + offset, &dac_val);78 if (err)79 return err;80 81 *val = dac_val;82 83 return IIO_VAL_INT;84}85 86static int cio_dac_write_raw(struct iio_dev *indio_dev,87 struct iio_chan_spec const *chan, int val, int val2, long mask)88{89 struct cio_dac_iio *const priv = iio_priv(indio_dev);90 const unsigned int offset = chan->channel * CIO_DAC_CHANNEL_STRIDE;91 92 if (mask != IIO_CHAN_INFO_RAW)93 return -EINVAL;94 95 /* DAC can only accept up to a 12-bit value */96 if ((unsigned int)val > 4095)97 return -EINVAL;98 99 return regmap_write(priv->map, CIO_DAC_BASE + offset, val);100}101 102static const struct iio_info cio_dac_info = {103 .read_raw = cio_dac_read_raw,104 .write_raw = cio_dac_write_raw105};106 107static const struct iio_chan_spec cio_dac_channels[CIO_DAC_NUM_CHAN] = {108 CIO_DAC_CHAN(0), CIO_DAC_CHAN(1), CIO_DAC_CHAN(2), CIO_DAC_CHAN(3),109 CIO_DAC_CHAN(4), CIO_DAC_CHAN(5), CIO_DAC_CHAN(6), CIO_DAC_CHAN(7),110 CIO_DAC_CHAN(8), CIO_DAC_CHAN(9), CIO_DAC_CHAN(10), CIO_DAC_CHAN(11),111 CIO_DAC_CHAN(12), CIO_DAC_CHAN(13), CIO_DAC_CHAN(14), CIO_DAC_CHAN(15)112};113 114static int cio_dac_probe(struct device *dev, unsigned int id)115{116 struct iio_dev *indio_dev;117 struct cio_dac_iio *priv;118 void __iomem *regs;119 120 indio_dev = devm_iio_device_alloc(dev, sizeof(*priv));121 if (!indio_dev)122 return -ENOMEM;123 124 if (!devm_request_region(dev, base[id], CIO_DAC_EXTENT,125 dev_name(dev))) {126 dev_err(dev, "Unable to request port addresses (0x%X-0x%X)\n",127 base[id], base[id] + CIO_DAC_EXTENT);128 return -EBUSY;129 }130 131 regs = devm_ioport_map(dev, base[id], CIO_DAC_EXTENT);132 if (!regs)133 return -ENOMEM;134 135 priv = iio_priv(indio_dev);136 priv->map = devm_regmap_init_mmio(dev, regs, &cio_dac_regmap_config);137 if (IS_ERR(priv->map))138 return dev_err_probe(dev, PTR_ERR(priv->map),139 "Unable to initialize register map\n");140 141 indio_dev->info = &cio_dac_info;142 indio_dev->modes = INDIO_DIRECT_MODE;143 indio_dev->channels = cio_dac_channels;144 indio_dev->num_channels = CIO_DAC_NUM_CHAN;145 indio_dev->name = dev_name(dev);146 147 return devm_iio_device_register(dev, indio_dev);148}149 150static struct isa_driver cio_dac_driver = {151 .probe = cio_dac_probe,152 .driver = {153 .name = "cio-dac"154 }155};156 157module_isa_driver(cio_dac_driver, num_cio_dac);158 159MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");160MODULE_DESCRIPTION("Measurement Computing CIO-DAC IIO driver");161MODULE_LICENSE("GPL v2");162