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/mfd/cros_ec.h> 18 #include <linux/module.h> 19 #include <linux/slab.h> 20 #include <linux/platform_data/cros_ec_commands.h> 21 #include <linux/platform_data/cros_ec_proto.h> 22 #include <linux/platform_device.h> 23 24 /* 25 * One channel for pressure, the other for timestamp. 26 */ 27 #define CROS_EC_BARO_MAX_CHANNELS (1 + 1) 28 29 /* State data for ec_sensors iio driver. */ 30 struct cros_ec_baro_state { 31 /* Shared by all sensors */ 32 struct cros_ec_sensors_core_state core; 33 34 struct iio_chan_spec channels[CROS_EC_BARO_MAX_CHANNELS]; 35 }; 36 37 static int cros_ec_baro_read(struct iio_dev *indio_dev, 38 struct iio_chan_spec const *chan, 39 int *val, int *val2, long mask) 40 { 41 struct cros_ec_baro_state *st = iio_priv(indio_dev); 42 u16 data = 0; 43 int ret; 44 int idx = chan->scan_index; 45 46 mutex_lock(&st->core.cmd_lock); 47 48 switch (mask) { 49 case IIO_CHAN_INFO_RAW: 50 ret = cros_ec_sensors_read_cmd(indio_dev, 1 << idx, 51 (s16 *)&data); 52 if (ret) 53 break; 54 55 *val = data; 56 ret = IIO_VAL_INT; 57 break; 58 case IIO_CHAN_INFO_SCALE: 59 st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE; 60 st->core.param.sensor_range.data = EC_MOTION_SENSE_NO_VALUE; 61 62 ret = cros_ec_motion_send_host_cmd(&st->core, 0); 63 if (ret) 64 break; 65 66 *val = st->core.resp->sensor_range.ret; 67 68 /* scale * in_pressure_raw --> kPa */ 69 *val2 = 10 << CROS_EC_SENSOR_BITS; 70 ret = IIO_VAL_FRACTIONAL; 71 break; 72 default: 73 ret = cros_ec_sensors_core_read(&st->core, chan, val, val2, 74 mask); 75 break; 76 } 77 78 mutex_unlock(&st->core.cmd_lock); 79 80 return ret; 81 } 82 83 static int cros_ec_baro_write(struct iio_dev *indio_dev, 84 struct iio_chan_spec const *chan, 85 int val, int val2, long mask) 86 { 87 struct cros_ec_baro_state *st = iio_priv(indio_dev); 88 int ret = 0; 89 90 mutex_lock(&st->core.cmd_lock); 91 92 switch (mask) { 93 case IIO_CHAN_INFO_SCALE: 94 st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE; 95 st->core.param.sensor_range.data = val; 96 97 /* Always roundup, so caller gets at least what it asks for. */ 98 st->core.param.sensor_range.roundup = 1; 99 100 if (cros_ec_motion_send_host_cmd(&st->core, 0)) 101 ret = -EIO; 102 break; 103 default: 104 ret = cros_ec_sensors_core_write(&st->core, chan, val, val2, 105 mask); 106 break; 107 } 108 109 mutex_unlock(&st->core.cmd_lock); 110 111 return ret; 112 } 113 114 static const struct iio_info cros_ec_baro_info = { 115 .read_raw = &cros_ec_baro_read, 116 .write_raw = &cros_ec_baro_write, 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->scan_type.realbits = CROS_EC_SENSOR_BITS; 153 channel->scan_type.storagebits = CROS_EC_SENSOR_BITS; 154 channel->scan_type.shift = 0; 155 channel->scan_index = 0; 156 channel->ext_info = cros_ec_sensors_ext_info; 157 channel->scan_type.sign = 'u'; 158 159 /* Sensor specific */ 160 switch (state->core.type) { 161 case MOTIONSENSE_TYPE_BARO: 162 channel->type = IIO_PRESSURE; 163 break; 164 default: 165 dev_warn(dev, "Unknown motion sensor\n"); 166 return -EINVAL; 167 } 168 169 /* Timestamp */ 170 channel++; 171 channel->type = IIO_TIMESTAMP; 172 channel->channel = -1; 173 channel->scan_index = 1; 174 channel->scan_type.sign = 's'; 175 channel->scan_type.realbits = 64; 176 channel->scan_type.storagebits = 64; 177 178 indio_dev->channels = state->channels; 179 indio_dev->num_channels = CROS_EC_BARO_MAX_CHANNELS; 180 181 state->core.read_ec_sensors_data = cros_ec_sensors_read_cmd; 182 183 ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL, 184 cros_ec_sensors_capture, NULL); 185 if (ret) 186 return ret; 187 188 return devm_iio_device_register(dev, indio_dev); 189 } 190 191 static const struct platform_device_id cros_ec_baro_ids[] = { 192 { 193 .name = "cros-ec-baro", 194 }, 195 { /* sentinel */ } 196 }; 197 MODULE_DEVICE_TABLE(platform, cros_ec_baro_ids); 198 199 static struct platform_driver cros_ec_baro_platform_driver = { 200 .driver = { 201 .name = "cros-ec-baro", 202 }, 203 .probe = cros_ec_baro_probe, 204 .id_table = cros_ec_baro_ids, 205 }; 206 module_platform_driver(cros_ec_baro_platform_driver); 207 208 MODULE_DESCRIPTION("ChromeOS EC barometer sensor driver"); 209 MODULE_LICENSE("GPL v2"); 210