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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 | // SPDX-License-Identifier: GPL-2.0-only /* * IIO driver for the Measurement Computing CIO-DAC * Copyright (C) 2016 William Breathitt Gray * * This driver supports the following Measurement Computing devices: CIO-DAC16, * CIO-DAC08, and PC104-DAC06. */ #include <linux/bits.h> #include <linux/device.h> #include <linux/err.h> #include <linux/iio/iio.h> #include <linux/iio/types.h> #include <linux/isa.h> #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/regmap.h> #include <linux/types.h> #define CIO_DAC_NUM_CHAN 16 #define CIO_DAC_CHAN(chan) { \ .type = IIO_VOLTAGE, \ .channel = chan, \ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ .indexed = 1, \ .output = 1 \ } #define CIO_DAC_EXTENT 32 static unsigned int base[max_num_isa_dev(CIO_DAC_EXTENT)]; static unsigned int num_cio_dac; module_param_hw_array(base, uint, ioport, &num_cio_dac, 0); MODULE_PARM_DESC(base, "Measurement Computing CIO-DAC base addresses"); #define CIO_DAC_BASE 0x00 #define CIO_DAC_CHANNEL_STRIDE 2 static bool cio_dac_precious_reg(struct device *dev, unsigned int reg) { /* * All registers are considered precious; if the XFER jumper is set on * the device, then no update occurs until a DAC register is read. */ return true; } static const struct regmap_config cio_dac_regmap_config = { .reg_bits = 16, .reg_stride = 2, .val_bits = 16, .io_port = true, .max_register = 0x1F, .precious_reg = cio_dac_precious_reg, }; /** * struct cio_dac_iio - IIO device private data structure * @map: Regmap for the device */ struct cio_dac_iio { struct regmap *map; }; static int cio_dac_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { struct cio_dac_iio *const priv = iio_priv(indio_dev); const unsigned int offset = chan->channel * CIO_DAC_CHANNEL_STRIDE; int err; unsigned int dac_val; if (mask != IIO_CHAN_INFO_RAW) return -EINVAL; err = regmap_read(priv->map, CIO_DAC_BASE + offset, &dac_val); if (err) return err; *val = dac_val; return IIO_VAL_INT; } static int cio_dac_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int val, int val2, long mask) { struct cio_dac_iio *const priv = iio_priv(indio_dev); const unsigned int offset = chan->channel * CIO_DAC_CHANNEL_STRIDE; if (mask != IIO_CHAN_INFO_RAW) return -EINVAL; /* DAC can only accept up to a 12-bit value */ if ((unsigned int)val > 4095) return -EINVAL; return regmap_write(priv->map, CIO_DAC_BASE + offset, val); } static const struct iio_info cio_dac_info = { .read_raw = cio_dac_read_raw, .write_raw = cio_dac_write_raw }; static const struct iio_chan_spec cio_dac_channels[CIO_DAC_NUM_CHAN] = { CIO_DAC_CHAN(0), CIO_DAC_CHAN(1), CIO_DAC_CHAN(2), CIO_DAC_CHAN(3), CIO_DAC_CHAN(4), CIO_DAC_CHAN(5), CIO_DAC_CHAN(6), CIO_DAC_CHAN(7), CIO_DAC_CHAN(8), CIO_DAC_CHAN(9), CIO_DAC_CHAN(10), CIO_DAC_CHAN(11), CIO_DAC_CHAN(12), CIO_DAC_CHAN(13), CIO_DAC_CHAN(14), CIO_DAC_CHAN(15) }; static int cio_dac_probe(struct device *dev, unsigned int id) { struct iio_dev *indio_dev; struct cio_dac_iio *priv; void __iomem *regs; indio_dev = devm_iio_device_alloc(dev, sizeof(*priv)); if (!indio_dev) return -ENOMEM; if (!devm_request_region(dev, base[id], CIO_DAC_EXTENT, dev_name(dev))) { dev_err(dev, "Unable to request port addresses (0x%X-0x%X)\n", base[id], base[id] + CIO_DAC_EXTENT); return -EBUSY; } regs = devm_ioport_map(dev, base[id], CIO_DAC_EXTENT); if (!regs) return -ENOMEM; priv = iio_priv(indio_dev); priv->map = devm_regmap_init_mmio(dev, regs, &cio_dac_regmap_config); if (IS_ERR(priv->map)) return dev_err_probe(dev, PTR_ERR(priv->map), "Unable to initialize register map\n"); indio_dev->info = &cio_dac_info; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->channels = cio_dac_channels; indio_dev->num_channels = CIO_DAC_NUM_CHAN; indio_dev->name = dev_name(dev); return devm_iio_device_register(dev, indio_dev); } static struct isa_driver cio_dac_driver = { .probe = cio_dac_probe, .driver = { .name = "cio-dac" } }; module_isa_driver(cio_dac_driver, num_cio_dac); MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>"); MODULE_DESCRIPTION("Measurement Computing CIO-DAC IIO driver"); MODULE_LICENSE("GPL v2"); |