1 /* 2 * cros_ec_baro - Driver for barometer sensor behind CrosEC. 3 * 4 * Copyright (C) 2017 Google, Inc 5 * 6 * This software is licensed under the terms of the GNU General Public 7 * License version 2, as published by the Free Software Foundation, and 8 * may be copied, distributed, and modified under those terms. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 */ 15 16 #include <linux/delay.h> 17 #include <linux/device.h> 18 #include <linux/iio/buffer.h> 19 #include <linux/iio/iio.h> 20 #include <linux/iio/kfifo_buf.h> 21 #include <linux/iio/trigger.h> 22 #include <linux/iio/triggered_buffer.h> 23 #include <linux/iio/trigger_consumer.h> 24 #include <linux/kernel.h> 25 #include <linux/mfd/cros_ec.h> 26 #include <linux/mfd/cros_ec_commands.h> 27 #include <linux/module.h> 28 #include <linux/slab.h> 29 #include <linux/platform_device.h> 30 31 #include "../common/cros_ec_sensors/cros_ec_sensors_core.h" 32 33 /* 34 * One channel for pressure, the other for timestamp. 35 */ 36 #define CROS_EC_BARO_MAX_CHANNELS (1 + 1) 37 38 /* State data for ec_sensors iio driver. */ 39 struct cros_ec_baro_state { 40 /* Shared by all sensors */ 41 struct cros_ec_sensors_core_state core; 42 43 struct iio_chan_spec channels[CROS_EC_BARO_MAX_CHANNELS]; 44 }; 45 46 static int cros_ec_baro_read(struct iio_dev *indio_dev, 47 struct iio_chan_spec const *chan, 48 int *val, int *val2, long mask) 49 { 50 struct cros_ec_baro_state *st = iio_priv(indio_dev); 51 u16 data = 0; 52 int ret = IIO_VAL_INT; 53 int idx = chan->scan_index; 54 55 mutex_lock(&st->core.cmd_lock); 56 57 switch (mask) { 58 case IIO_CHAN_INFO_RAW: 59 if (cros_ec_sensors_read_cmd(indio_dev, 1 << idx, 60 (s16 *)&data) < 0) 61 ret = -EIO; 62 *val = data; 63 break; 64 case IIO_CHAN_INFO_SCALE: 65 st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE; 66 st->core.param.sensor_range.data = EC_MOTION_SENSE_NO_VALUE; 67 68 if (cros_ec_motion_send_host_cmd(&st->core, 0)) { 69 ret = -EIO; 70 break; 71 } 72 *val = st->core.resp->sensor_range.ret; 73 74 /* scale * in_pressure_raw --> kPa */ 75 *val2 = 10 << CROS_EC_SENSOR_BITS; 76 ret = IIO_VAL_FRACTIONAL; 77 break; 78 default: 79 ret = cros_ec_sensors_core_read(&st->core, chan, val, val2, 80 mask); 81 break; 82 } 83 84 mutex_unlock(&st->core.cmd_lock); 85 86 return ret; 87 } 88 89 static int cros_ec_baro_write(struct iio_dev *indio_dev, 90 struct iio_chan_spec const *chan, 91 int val, int val2, long mask) 92 { 93 struct cros_ec_baro_state *st = iio_priv(indio_dev); 94 int ret = 0; 95 96 mutex_lock(&st->core.cmd_lock); 97 98 switch (mask) { 99 case IIO_CHAN_INFO_SCALE: 100 st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE; 101 st->core.param.sensor_range.data = val; 102 103 /* Always roundup, so caller gets at least what it asks for. */ 104 st->core.param.sensor_range.roundup = 1; 105 106 if (cros_ec_motion_send_host_cmd(&st->core, 0)) 107 ret = -EIO; 108 break; 109 default: 110 ret = cros_ec_sensors_core_write(&st->core, chan, val, val2, 111 mask); 112 break; 113 } 114 115 mutex_unlock(&st->core.cmd_lock); 116 117 return ret; 118 } 119 120 static const struct iio_info cros_ec_baro_info = { 121 .read_raw = &cros_ec_baro_read, 122 .write_raw = &cros_ec_baro_write, 123 .driver_module = THIS_MODULE, 124 }; 125 126 static int cros_ec_baro_probe(struct platform_device *pdev) 127 { 128 struct device *dev = &pdev->dev; 129 struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent); 130 struct cros_ec_device *ec_device; 131 struct iio_dev *indio_dev; 132 struct cros_ec_baro_state *state; 133 struct iio_chan_spec *channel; 134 int ret; 135 136 if (!ec_dev || !ec_dev->ec_dev) { 137 dev_warn(dev, "No CROS EC device found.\n"); 138 return -EINVAL; 139 } 140 ec_device = ec_dev->ec_dev; 141 142 indio_dev = devm_iio_device_alloc(dev, sizeof(*state)); 143 if (!indio_dev) 144 return -ENOMEM; 145 146 ret = cros_ec_sensors_core_init(pdev, indio_dev, true); 147 if (ret) 148 return ret; 149 150 indio_dev->info = &cros_ec_baro_info; 151 state = iio_priv(indio_dev); 152 state->core.type = state->core.resp->info.type; 153 state->core.loc = state->core.resp->info.location; 154 channel = state->channels; 155 /* Common part */ 156 channel->info_mask_separate = BIT(IIO_CHAN_INFO_RAW); 157 channel->info_mask_shared_by_all = 158 BIT(IIO_CHAN_INFO_SCALE) | 159 BIT(IIO_CHAN_INFO_SAMP_FREQ) | 160 BIT(IIO_CHAN_INFO_FREQUENCY); 161 channel->scan_type.realbits = CROS_EC_SENSOR_BITS; 162 channel->scan_type.storagebits = CROS_EC_SENSOR_BITS; 163 channel->scan_type.shift = 0; 164 channel->scan_index = 0; 165 channel->ext_info = cros_ec_sensors_ext_info; 166 channel->scan_type.sign = 'u'; 167 168 state->core.calib[0] = 0; 169 170 /* Sensor specific */ 171 switch (state->core.type) { 172 case MOTIONSENSE_TYPE_BARO: 173 channel->type = IIO_PRESSURE; 174 break; 175 default: 176 dev_warn(dev, "Unknown motion sensor\n"); 177 return -EINVAL; 178 } 179 180 /* Timestamp */ 181 channel++; 182 channel->type = IIO_TIMESTAMP; 183 channel->channel = -1; 184 channel->scan_index = 1; 185 channel->scan_type.sign = 's'; 186 channel->scan_type.realbits = 64; 187 channel->scan_type.storagebits = 64; 188 189 indio_dev->channels = state->channels; 190 indio_dev->num_channels = CROS_EC_BARO_MAX_CHANNELS; 191 192 state->core.read_ec_sensors_data = cros_ec_sensors_read_cmd; 193 194 ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL, 195 cros_ec_sensors_capture, NULL); 196 if (ret) 197 return ret; 198 199 return devm_iio_device_register(dev, indio_dev); 200 } 201 202 static const struct platform_device_id cros_ec_baro_ids[] = { 203 { 204 .name = "cros-ec-baro", 205 }, 206 { /* sentinel */ } 207 }; 208 MODULE_DEVICE_TABLE(platform, cros_ec_baro_ids); 209 210 static struct platform_driver cros_ec_baro_platform_driver = { 211 .driver = { 212 .name = "cros-ec-baro", 213 }, 214 .probe = cros_ec_baro_probe, 215 .id_table = cros_ec_baro_ids, 216 }; 217 module_platform_driver(cros_ec_baro_platform_driver); 218 219 MODULE_DESCRIPTION("ChromeOS EC barometer sensor driver"); 220 MODULE_LICENSE("GPL v2"); 221