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1// SPDX-License-Identifier: GPL-2.0+2/*3 * mb1232.c - Support for MaxBotix I2CXL-MaxSonar-EZ series ultrasonic4 * ranger with i2c interface5 * actually tested with mb1232 type6 *7 * Copyright (c) 2019 Andreas Klinger <ak@it-klinger.de>8 *9 * For details about the device see:10 * https://www.maxbotix.com/documents/I2CXL-MaxSonar-EZ_Datasheet.pdf11 */12 13#include <linux/bitops.h>14#include <linux/err.h>15#include <linux/i2c.h>16#include <linux/delay.h>17#include <linux/mod_devicetable.h>18#include <linux/module.h>19#include <linux/property.h>20 21#include <linux/iio/iio.h>22#include <linux/iio/sysfs.h>23#include <linux/iio/buffer.h>24#include <linux/iio/trigger_consumer.h>25#include <linux/iio/triggered_buffer.h>26 27/* registers of MaxSonar device */28#define MB1232_RANGE_COMMAND 0x51 /* Command for reading range */29#define MB1232_ADDR_UNLOCK_1 0xAA /* Command 1 for changing address */30#define MB1232_ADDR_UNLOCK_2 0xA5 /* Command 2 for changing address */31 32struct mb1232_data {33 struct i2c_client *client;34 35 struct mutex lock;36 37 /*38 * optionally a gpio can be used to announce when ranging has39 * finished40 * since we are just using the falling trigger of it we request41 * only the interrupt for announcing when data is ready to be read42 */43 struct completion ranging;44 int irqnr;45 /* Ensure correct alignment of data to push to IIO buffer */46 struct {47 s16 distance;48 s64 ts __aligned(8);49 } scan;50};51 52static irqreturn_t mb1232_handle_irq(int irq, void *dev_id)53{54 struct iio_dev *indio_dev = dev_id;55 struct mb1232_data *data = iio_priv(indio_dev);56 57 complete(&data->ranging);58 59 return IRQ_HANDLED;60}61 62static s16 mb1232_read_distance(struct mb1232_data *data)63{64 struct i2c_client *client = data->client;65 int ret;66 s16 distance;67 __be16 buf;68 69 mutex_lock(&data->lock);70 71 reinit_completion(&data->ranging);72 73 ret = i2c_smbus_write_byte(client, MB1232_RANGE_COMMAND);74 if (ret < 0) {75 dev_err(&client->dev, "write command - err: %d\n", ret);76 goto error_unlock;77 }78 79 if (data->irqnr > 0) {80 /* it cannot take more than 100 ms */81 ret = wait_for_completion_killable_timeout(&data->ranging,82 HZ/10);83 if (ret < 0)84 goto error_unlock;85 else if (ret == 0) {86 ret = -ETIMEDOUT;87 goto error_unlock;88 }89 } else {90 /* use simple sleep if announce irq is not connected */91 msleep(15);92 }93 94 ret = i2c_master_recv(client, (char *)&buf, sizeof(buf));95 if (ret < 0) {96 dev_err(&client->dev, "i2c_master_recv: ret=%d\n", ret);97 goto error_unlock;98 }99 100 distance = __be16_to_cpu(buf);101 /* check for not returning misleading error codes */102 if (distance < 0) {103 dev_err(&client->dev, "distance=%d\n", distance);104 ret = -EINVAL;105 goto error_unlock;106 }107 108 mutex_unlock(&data->lock);109 110 return distance;111 112error_unlock:113 mutex_unlock(&data->lock);114 115 return ret;116}117 118static irqreturn_t mb1232_trigger_handler(int irq, void *p)119{120 struct iio_poll_func *pf = p;121 struct iio_dev *indio_dev = pf->indio_dev;122 struct mb1232_data *data = iio_priv(indio_dev);123 124 data->scan.distance = mb1232_read_distance(data);125 if (data->scan.distance < 0)126 goto err;127 128 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,129 pf->timestamp);130 131err:132 iio_trigger_notify_done(indio_dev->trig);133 return IRQ_HANDLED;134}135 136static int mb1232_read_raw(struct iio_dev *indio_dev,137 struct iio_chan_spec const *channel, int *val,138 int *val2, long mask)139{140 struct mb1232_data *data = iio_priv(indio_dev);141 int ret;142 143 if (channel->type != IIO_DISTANCE)144 return -EINVAL;145 146 switch (mask) {147 case IIO_CHAN_INFO_RAW:148 ret = mb1232_read_distance(data);149 if (ret < 0)150 return ret;151 *val = ret;152 return IIO_VAL_INT;153 case IIO_CHAN_INFO_SCALE:154 /* 1 LSB is 1 cm */155 *val = 0;156 *val2 = 10000;157 return IIO_VAL_INT_PLUS_MICRO;158 default:159 return -EINVAL;160 }161}162 163static const struct iio_chan_spec mb1232_channels[] = {164 {165 .type = IIO_DISTANCE,166 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |167 BIT(IIO_CHAN_INFO_SCALE),168 .scan_index = 0,169 .scan_type = {170 .sign = 's',171 .realbits = 16,172 .storagebits = 16,173 .endianness = IIO_CPU,174 },175 },176 IIO_CHAN_SOFT_TIMESTAMP(1),177};178 179static const struct iio_info mb1232_info = {180 .read_raw = mb1232_read_raw,181};182 183static int mb1232_probe(struct i2c_client *client)184{185 const struct i2c_device_id *id = i2c_client_get_device_id(client);186 struct iio_dev *indio_dev;187 struct mb1232_data *data;188 int ret;189 struct device *dev = &client->dev;190 191 if (!i2c_check_functionality(client->adapter,192 I2C_FUNC_SMBUS_READ_BYTE |193 I2C_FUNC_SMBUS_WRITE_BYTE))194 return -ENODEV;195 196 indio_dev = devm_iio_device_alloc(dev, sizeof(*data));197 if (!indio_dev)198 return -ENOMEM;199 200 data = iio_priv(indio_dev);201 i2c_set_clientdata(client, indio_dev);202 data->client = client;203 204 indio_dev->info = &mb1232_info;205 indio_dev->name = id->name;206 indio_dev->modes = INDIO_DIRECT_MODE;207 indio_dev->channels = mb1232_channels;208 indio_dev->num_channels = ARRAY_SIZE(mb1232_channels);209 210 mutex_init(&data->lock);211 212 init_completion(&data->ranging);213 214 data->irqnr = fwnode_irq_get(dev_fwnode(&client->dev), 0);215 if (data->irqnr > 0) {216 ret = devm_request_irq(dev, data->irqnr, mb1232_handle_irq,217 IRQF_TRIGGER_FALLING, id->name, indio_dev);218 if (ret < 0) {219 dev_err(dev, "request_irq: %d\n", ret);220 return ret;221 }222 }223 224 ret = devm_iio_triggered_buffer_setup(dev, indio_dev,225 iio_pollfunc_store_time, mb1232_trigger_handler, NULL);226 if (ret < 0) {227 dev_err(dev, "setup of iio triggered buffer failed\n");228 return ret;229 }230 231 return devm_iio_device_register(dev, indio_dev);232}233 234static const struct of_device_id of_mb1232_match[] = {235 { .compatible = "maxbotix,mb1202", },236 { .compatible = "maxbotix,mb1212", },237 { .compatible = "maxbotix,mb1222", },238 { .compatible = "maxbotix,mb1232", },239 { .compatible = "maxbotix,mb1242", },240 { .compatible = "maxbotix,mb7040", },241 { .compatible = "maxbotix,mb7137", },242 {},243};244 245MODULE_DEVICE_TABLE(of, of_mb1232_match);246 247static const struct i2c_device_id mb1232_id[] = {248 { "maxbotix-mb1202", },249 { "maxbotix-mb1212", },250 { "maxbotix-mb1222", },251 { "maxbotix-mb1232", },252 { "maxbotix-mb1242", },253 { "maxbotix-mb7040", },254 { "maxbotix-mb7137", },255 { }256};257MODULE_DEVICE_TABLE(i2c, mb1232_id);258 259static struct i2c_driver mb1232_driver = {260 .driver = {261 .name = "maxbotix-mb1232",262 .of_match_table = of_mb1232_match,263 },264 .probe = mb1232_probe,265 .id_table = mb1232_id,266};267module_i2c_driver(mb1232_driver);268 269MODULE_AUTHOR("Andreas Klinger <ak@it-klinger.de>");270MODULE_DESCRIPTION("Maxbotix I2CXL-MaxSonar i2c ultrasonic ranger driver");271MODULE_LICENSE("GPL");272