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1// SPDX-License-Identifier: GPL-2.02/*3 * Driver for older Chrome OS EC accelerometer4 *5 * Copyright 2017 Google, Inc6 *7 * This driver uses the memory mapper cros-ec interface to communicate8 * with the Chrome OS EC about accelerometer data or older commands.9 * Accelerometer access is presented through iio sysfs.10 */11 12#include <linux/delay.h>13#include <linux/device.h>14#include <linux/iio/buffer.h>15#include <linux/iio/common/cros_ec_sensors_core.h>16#include <linux/iio/iio.h>17#include <linux/iio/kfifo_buf.h>18#include <linux/iio/trigger_consumer.h>19#include <linux/iio/triggered_buffer.h>20#include <linux/kernel.h>21#include <linux/module.h>22#include <linux/slab.h>23#include <linux/platform_data/cros_ec_commands.h>24#include <linux/platform_data/cros_ec_proto.h>25#include <linux/platform_device.h>26 27#define DRV_NAME "cros-ec-accel-legacy"28 29#define CROS_EC_SENSOR_LEGACY_NUM 230/*31 * Sensor scale hard coded at 10 bits per g, computed as:32 * g / (2^10 - 1) = 0.009586168; with g = 9.80665 m.s^-233 */34#define ACCEL_LEGACY_NSCALE 958616835 36/*37 * Sensor frequency is hard-coded to 10Hz.38 */39static const int cros_ec_legacy_sample_freq[] = { 10, 0 };40 41static int cros_ec_accel_legacy_read_cmd(struct iio_dev *indio_dev,42 unsigned long scan_mask, s16 *data)43{44 struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);45 int ret;46 unsigned int i;47 u8 sensor_num;48 49 /*50 * Read all sensor data through a command.51 * Save sensor_num, it is assumed to stay.52 */53 sensor_num = st->param.info.sensor_num;54 st->param.cmd = MOTIONSENSE_CMD_DUMP;55 st->param.dump.max_sensor_count = CROS_EC_SENSOR_LEGACY_NUM;56 ret = cros_ec_motion_send_host_cmd(st,57 sizeof(st->resp->dump) + CROS_EC_SENSOR_LEGACY_NUM *58 sizeof(struct ec_response_motion_sensor_data));59 st->param.info.sensor_num = sensor_num;60 if (ret != 0) {61 dev_warn(&indio_dev->dev, "Unable to read sensor data\n");62 return ret;63 }64 65 for_each_set_bit(i, &scan_mask, iio_get_masklength(indio_dev)) {66 *data = st->resp->dump.sensor[sensor_num].data[i] *67 st->sign[i];68 data++;69 }70 71 return 0;72}73 74static int cros_ec_accel_legacy_read(struct iio_dev *indio_dev,75 struct iio_chan_spec const *chan,76 int *val, int *val2, long mask)77{78 struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);79 s16 data = 0;80 int ret;81 int idx = chan->scan_index;82 83 mutex_lock(&st->cmd_lock);84 85 switch (mask) {86 case IIO_CHAN_INFO_RAW:87 ret = st->read_ec_sensors_data(indio_dev, 1 << idx, &data);88 if (ret < 0)89 break;90 ret = IIO_VAL_INT;91 *val = data;92 break;93 case IIO_CHAN_INFO_SCALE:94 WARN_ON(st->type != MOTIONSENSE_TYPE_ACCEL);95 *val = 0;96 *val2 = ACCEL_LEGACY_NSCALE;97 ret = IIO_VAL_INT_PLUS_NANO;98 break;99 case IIO_CHAN_INFO_CALIBBIAS:100 /* Calibration not supported. */101 *val = 0;102 ret = IIO_VAL_INT;103 break;104 case IIO_CHAN_INFO_SAMP_FREQ:105 *val = cros_ec_legacy_sample_freq[0];106 *val2 = cros_ec_legacy_sample_freq[1];107 ret = IIO_VAL_INT_PLUS_MICRO;108 break;109 default:110 ret = cros_ec_sensors_core_read(st, chan, val, val2,111 mask);112 break;113 }114 mutex_unlock(&st->cmd_lock);115 116 return ret;117}118 119static int cros_ec_accel_legacy_write(struct iio_dev *indio_dev,120 struct iio_chan_spec const *chan,121 int val, int val2, long mask)122{123 /*124 * Do nothing but don't return an error code to allow calibration125 * script to work.126 */127 if (mask == IIO_CHAN_INFO_CALIBBIAS)128 return 0;129 130 return -EINVAL;131}132 133/**134 * cros_ec_accel_legacy_read_avail() - get available values135 * @indio_dev: pointer to state information for device136 * @chan: channel specification structure table137 * @vals: list of available values138 * @type: type of data returned139 * @length: number of data returned in the array140 * @mask: specifies which values to be requested141 *142 * Return: an error code or IIO_AVAIL_LIST143 */144static int cros_ec_accel_legacy_read_avail(struct iio_dev *indio_dev,145 struct iio_chan_spec const *chan,146 const int **vals,147 int *type,148 int *length,149 long mask)150{151 switch (mask) {152 case IIO_CHAN_INFO_SAMP_FREQ:153 *length = ARRAY_SIZE(cros_ec_legacy_sample_freq);154 *vals = cros_ec_legacy_sample_freq;155 *type = IIO_VAL_INT_PLUS_MICRO;156 return IIO_AVAIL_LIST;157 }158 159 return -EINVAL;160}161 162static const struct iio_info cros_ec_accel_legacy_info = {163 .read_raw = &cros_ec_accel_legacy_read,164 .write_raw = &cros_ec_accel_legacy_write,165 .read_avail = &cros_ec_accel_legacy_read_avail,166};167 168/*169 * Present the channel using HTML5 standard:170 * need to invert X and Y and invert some lid axis.171 */172#define CROS_EC_ACCEL_ROTATE_AXIS(_axis) \173 ((_axis) == CROS_EC_SENSOR_Z ? CROS_EC_SENSOR_Z : \174 ((_axis) == CROS_EC_SENSOR_X ? CROS_EC_SENSOR_Y : \175 CROS_EC_SENSOR_X))176 177#define CROS_EC_ACCEL_LEGACY_CHAN(_axis) \178 { \179 .type = IIO_ACCEL, \180 .channel2 = IIO_MOD_X + (_axis), \181 .modified = 1, \182 .info_mask_separate = \183 BIT(IIO_CHAN_INFO_RAW) | \184 BIT(IIO_CHAN_INFO_CALIBBIAS), \185 .info_mask_shared_by_all = \186 BIT(IIO_CHAN_INFO_SCALE) | \187 BIT(IIO_CHAN_INFO_SAMP_FREQ), \188 .info_mask_shared_by_all_available = \189 BIT(IIO_CHAN_INFO_SAMP_FREQ), \190 .ext_info = cros_ec_sensors_ext_info, \191 .scan_type = { \192 .sign = 's', \193 .realbits = CROS_EC_SENSOR_BITS, \194 .storagebits = CROS_EC_SENSOR_BITS, \195 }, \196 .scan_index = CROS_EC_ACCEL_ROTATE_AXIS(_axis), \197 } \198 199static const struct iio_chan_spec cros_ec_accel_legacy_channels[] = {200 CROS_EC_ACCEL_LEGACY_CHAN(CROS_EC_SENSOR_X),201 CROS_EC_ACCEL_LEGACY_CHAN(CROS_EC_SENSOR_Y),202 CROS_EC_ACCEL_LEGACY_CHAN(CROS_EC_SENSOR_Z),203 IIO_CHAN_SOFT_TIMESTAMP(CROS_EC_SENSOR_MAX_AXIS)204};205 206static int cros_ec_accel_legacy_probe(struct platform_device *pdev)207{208 struct device *dev = &pdev->dev;209 struct iio_dev *indio_dev;210 struct cros_ec_sensors_core_state *state;211 int ret;212 213 indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*state));214 if (!indio_dev)215 return -ENOMEM;216 217 ret = cros_ec_sensors_core_init(pdev, indio_dev, true,218 cros_ec_sensors_capture);219 if (ret)220 return ret;221 222 indio_dev->info = &cros_ec_accel_legacy_info;223 state = iio_priv(indio_dev);224 225 if (state->ec->cmd_readmem != NULL)226 state->read_ec_sensors_data = cros_ec_sensors_read_lpc;227 else228 state->read_ec_sensors_data = cros_ec_accel_legacy_read_cmd;229 230 indio_dev->channels = cros_ec_accel_legacy_channels;231 indio_dev->num_channels = ARRAY_SIZE(cros_ec_accel_legacy_channels);232 /* The lid sensor needs to be presented inverted. */233 if (!strcmp(indio_dev->label, "accel-display")) {234 state->sign[CROS_EC_SENSOR_X] = -1;235 state->sign[CROS_EC_SENSOR_Z] = -1;236 }237 238 return cros_ec_sensors_core_register(dev, indio_dev, NULL);239}240 241static struct platform_driver cros_ec_accel_platform_driver = {242 .driver = {243 .name = DRV_NAME,244 },245 .probe = cros_ec_accel_legacy_probe,246};247module_platform_driver(cros_ec_accel_platform_driver);248 249MODULE_DESCRIPTION("ChromeOS EC legacy accelerometer driver");250MODULE_AUTHOR("Gwendal Grignou <gwendal@chromium.org>");251MODULE_LICENSE("GPL v2");252MODULE_ALIAS("platform:" DRV_NAME);253