1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * cros_ec_baro - Driver for barometer sensor behind CrosEC. 4 * 5 * Copyright (C) 2017 Google, Inc 6 */ 7 8 #include <linux/device.h> 9 #include <linux/iio/buffer.h> 10 #include <linux/iio/common/cros_ec_sensors_core.h> 11 #include <linux/iio/iio.h> 12 #include <linux/iio/kfifo_buf.h> 13 #include <linux/iio/trigger.h> 14 #include <linux/iio/triggered_buffer.h> 15 #include <linux/iio/trigger_consumer.h> 16 #include <linux/kernel.h> 17 #include <linux/module.h> 18 #include <linux/slab.h> 19 #include <linux/platform_data/cros_ec_commands.h> 20 #include <linux/platform_data/cros_ec_proto.h> 21 #include <linux/platform_device.h> 22 23 /* 24 * One channel for pressure, the other for timestamp. 25 */ 26 #define CROS_EC_BARO_MAX_CHANNELS (1 + 1) 27 28 /* State data for ec_sensors iio driver. */ 29 struct cros_ec_baro_state { 30 /* Shared by all sensors */ 31 struct cros_ec_sensors_core_state core; 32 33 struct iio_chan_spec channels[CROS_EC_BARO_MAX_CHANNELS]; 34 }; 35 36 static int cros_ec_baro_read(struct iio_dev *indio_dev, 37 struct iio_chan_spec const *chan, 38 int *val, int *val2, long mask) 39 { 40 struct cros_ec_baro_state *st = iio_priv(indio_dev); 41 u16 data = 0; 42 int ret; 43 int idx = chan->scan_index; 44 45 mutex_lock(&st->core.cmd_lock); 46 47 switch (mask) { 48 case IIO_CHAN_INFO_RAW: 49 ret = cros_ec_sensors_read_cmd(indio_dev, 1 << idx, 50 (s16 *)&data); 51 if (ret) 52 break; 53 54 *val = data; 55 ret = IIO_VAL_INT; 56 break; 57 case IIO_CHAN_INFO_SCALE: 58 st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE; 59 st->core.param.sensor_range.data = EC_MOTION_SENSE_NO_VALUE; 60 61 ret = cros_ec_motion_send_host_cmd(&st->core, 0); 62 if (ret) 63 break; 64 65 *val = st->core.resp->sensor_range.ret; 66 67 /* scale * in_pressure_raw --> kPa */ 68 *val2 = 10 << CROS_EC_SENSOR_BITS; 69 ret = IIO_VAL_FRACTIONAL; 70 break; 71 default: 72 ret = cros_ec_sensors_core_read(&st->core, chan, val, val2, 73 mask); 74 break; 75 } 76 77 mutex_unlock(&st->core.cmd_lock); 78 79 return ret; 80 } 81 82 static int cros_ec_baro_write(struct iio_dev *indio_dev, 83 struct iio_chan_spec const *chan, 84 int val, int val2, long mask) 85 { 86 struct cros_ec_baro_state *st = iio_priv(indio_dev); 87 int ret = 0; 88 89 mutex_lock(&st->core.cmd_lock); 90 91 switch (mask) { 92 case IIO_CHAN_INFO_SCALE: 93 st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE; 94 st->core.param.sensor_range.data = val; 95 96 /* Always roundup, so caller gets at least what it asks for. */ 97 st->core.param.sensor_range.roundup = 1; 98 99 if (cros_ec_motion_send_host_cmd(&st->core, 0)) 100 ret = -EIO; 101 break; 102 default: 103 ret = cros_ec_sensors_core_write(&st->core, chan, val, val2, 104 mask); 105 break; 106 } 107 108 mutex_unlock(&st->core.cmd_lock); 109 110 return ret; 111 } 112 113 static const struct iio_info cros_ec_baro_info = { 114 .read_raw = &cros_ec_baro_read, 115 .write_raw = &cros_ec_baro_write, 116 .read_avail = &cros_ec_sensors_core_read_avail, 117 }; 118 119 static int cros_ec_baro_probe(struct platform_device *pdev) 120 { 121 struct device *dev = &pdev->dev; 122 struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent); 123 struct iio_dev *indio_dev; 124 struct cros_ec_baro_state *state; 125 struct iio_chan_spec *channel; 126 int ret; 127 128 if (!ec_dev || !ec_dev->ec_dev) { 129 dev_warn(dev, "No CROS EC device found.\n"); 130 return -EINVAL; 131 } 132 133 indio_dev = devm_iio_device_alloc(dev, sizeof(*state)); 134 if (!indio_dev) 135 return -ENOMEM; 136 137 ret = cros_ec_sensors_core_init(pdev, indio_dev, true); 138 if (ret) 139 return ret; 140 141 indio_dev->info = &cros_ec_baro_info; 142 state = iio_priv(indio_dev); 143 state->core.type = state->core.resp->info.type; 144 state->core.loc = state->core.resp->info.location; 145 channel = state->channels; 146 /* Common part */ 147 channel->info_mask_separate = BIT(IIO_CHAN_INFO_RAW); 148 channel->info_mask_shared_by_all = 149 BIT(IIO_CHAN_INFO_SCALE) | 150 BIT(IIO_CHAN_INFO_SAMP_FREQ) | 151 BIT(IIO_CHAN_INFO_FREQUENCY); 152 channel->info_mask_shared_by_all_available = 153 BIT(IIO_CHAN_INFO_SAMP_FREQ); 154 channel->scan_type.realbits = CROS_EC_SENSOR_BITS; 155 channel->scan_type.storagebits = CROS_EC_SENSOR_BITS; 156 channel->scan_type.shift = 0; 157 channel->scan_index = 0; 158 channel->ext_info = cros_ec_sensors_ext_info; 159 channel->scan_type.sign = 'u'; 160 161 /* Sensor specific */ 162 switch (state->core.type) { 163 case MOTIONSENSE_TYPE_BARO: 164 channel->type = IIO_PRESSURE; 165 break; 166 default: 167 dev_warn(dev, "Unknown motion sensor\n"); 168 return -EINVAL; 169 } 170 171 /* Timestamp */ 172 channel++; 173 channel->type = IIO_TIMESTAMP; 174 channel->channel = -1; 175 channel->scan_index = 1; 176 channel->scan_type.sign = 's'; 177 channel->scan_type.realbits = 64; 178 channel->scan_type.storagebits = 64; 179 180 indio_dev->channels = state->channels; 181 indio_dev->num_channels = CROS_EC_BARO_MAX_CHANNELS; 182 183 state->core.read_ec_sensors_data = cros_ec_sensors_read_cmd; 184 185 ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL, 186 cros_ec_sensors_capture, NULL); 187 if (ret) 188 return ret; 189 190 return devm_iio_device_register(dev, indio_dev); 191 } 192 193 static const struct platform_device_id cros_ec_baro_ids[] = { 194 { 195 .name = "cros-ec-baro", 196 }, 197 { /* sentinel */ } 198 }; 199 MODULE_DEVICE_TABLE(platform, cros_ec_baro_ids); 200 201 static struct platform_driver cros_ec_baro_platform_driver = { 202 .driver = { 203 .name = "cros-ec-baro", 204 }, 205 .probe = cros_ec_baro_probe, 206 .id_table = cros_ec_baro_ids, 207 }; 208 module_platform_driver(cros_ec_baro_platform_driver); 209 210 MODULE_DESCRIPTION("ChromeOS EC barometer sensor driver"); 211 MODULE_LICENSE("GPL v2"); 212