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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 | // SPDX-License-Identifier: GPL-2.0-only /* Hwmon client for industrial I/O devices * * Copyright (c) 2011 Jonathan Cameron */ #include <linux/kernel.h> #include <linux/slab.h> #include <linux/mod_devicetable.h> #include <linux/module.h> #include <linux/err.h> #include <linux/platform_device.h> #include <linux/property.h> #include <linux/hwmon.h> #include <linux/hwmon-sysfs.h> #include <linux/iio/consumer.h> #include <linux/iio/types.h> /** * struct iio_hwmon_state - device instance state * @channels: filled with array of channels from iio * @num_channels: number of channels in channels (saves counting twice) * @attr_group: the group of attributes * @groups: null terminated array of attribute groups * @attrs: null terminated array of attribute pointers. */ struct iio_hwmon_state { struct iio_channel *channels; int num_channels; struct attribute_group attr_group; const struct attribute_group *groups[2]; struct attribute **attrs; }; /* * Assumes that IIO and hwmon operate in the same base units. * This is supposed to be true, but needs verification for * new channel types. */ static ssize_t iio_hwmon_read_val(struct device *dev, struct device_attribute *attr, char *buf) { int result; int ret; struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr); struct iio_hwmon_state *state = dev_get_drvdata(dev); struct iio_channel *chan = &state->channels[sattr->index]; enum iio_chan_type type; ret = iio_read_channel_processed(chan, &result); if (ret < 0) return ret; ret = iio_get_channel_type(chan, &type); if (ret < 0) return ret; if (type == IIO_POWER) result *= 1000; /* mili-Watts to micro-Watts conversion */ return sprintf(buf, "%d\n", result); } static int iio_hwmon_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct iio_hwmon_state *st; struct sensor_device_attribute *a; int ret, i; int in_i = 1, temp_i = 1, curr_i = 1, humidity_i = 1, power_i = 1; enum iio_chan_type type; struct iio_channel *channels; struct device *hwmon_dev; char *sname; channels = devm_iio_channel_get_all(dev); if (IS_ERR(channels)) { ret = PTR_ERR(channels); if (ret == -ENODEV) ret = -EPROBE_DEFER; return dev_err_probe(dev, ret, "Failed to get channels\n"); } st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL); if (st == NULL) return -ENOMEM; st->channels = channels; /* count how many attributes we have */ while (st->channels[st->num_channels].indio_dev) st->num_channels++; st->attrs = devm_kcalloc(dev, st->num_channels + 1, sizeof(*st->attrs), GFP_KERNEL); if (st->attrs == NULL) return -ENOMEM; for (i = 0; i < st->num_channels; i++) { const char *prefix; int n; a = devm_kzalloc(dev, sizeof(*a), GFP_KERNEL); if (a == NULL) return -ENOMEM; sysfs_attr_init(&a->dev_attr.attr); ret = iio_get_channel_type(&st->channels[i], &type); if (ret < 0) return ret; switch (type) { case IIO_VOLTAGE: n = in_i++; prefix = "in"; break; case IIO_TEMP: n = temp_i++; prefix = "temp"; break; case IIO_CURRENT: n = curr_i++; prefix = "curr"; break; case IIO_POWER: n = power_i++; prefix = "power"; break; case IIO_HUMIDITYRELATIVE: n = humidity_i++; prefix = "humidity"; break; default: return -EINVAL; } a->dev_attr.attr.name = devm_kasprintf(dev, GFP_KERNEL, "%s%d_input", prefix, n); if (a->dev_attr.attr.name == NULL) return -ENOMEM; a->dev_attr.show = iio_hwmon_read_val; a->dev_attr.attr.mode = 0444; a->index = i; st->attrs[i] = &a->dev_attr.attr; } st->attr_group.attrs = st->attrs; st->groups[0] = &st->attr_group; if (dev_fwnode(dev)) { sname = devm_kasprintf(dev, GFP_KERNEL, "%pfwP", dev_fwnode(dev)); if (!sname) return -ENOMEM; strreplace(sname, '-', '_'); } else { sname = "iio_hwmon"; } hwmon_dev = devm_hwmon_device_register_with_groups(dev, sname, st, st->groups); return PTR_ERR_OR_ZERO(hwmon_dev); } static const struct of_device_id iio_hwmon_of_match[] = { { .compatible = "iio-hwmon", }, { } }; MODULE_DEVICE_TABLE(of, iio_hwmon_of_match); static struct platform_driver iio_hwmon_driver = { .driver = { .name = "iio_hwmon", .of_match_table = iio_hwmon_of_match, }, .probe = iio_hwmon_probe, }; module_platform_driver(iio_hwmon_driver); MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>"); MODULE_DESCRIPTION("IIO to hwmon driver"); MODULE_LICENSE("GPL v2"); |