Re: [PATCH] iio: proximity: Add driver support for ST's VL53L0X ToF ranging sensor.
From: Song Qiang
Date: Mon Sep 10 2018 - 22:19:46 EST
On Mon, Sep 10, 2018 at 06:12:43PM +0300, Andy Shevchenko wrote:
> On Mon, Sep 10, 2018 at 10:42:59PM +0800, Song Qiang wrote:
> > This driver was originally written by ST in 2016 as a misc input device,
> > and hasn't been maintained for a long time. I grabbed some code from
> > it's API and reformed it to a iio proximity device driver.
> > This version of driver uses i2c bus to talk to the sensor and
> > polling for measuring completes, so no irq line is needed.
> > This version of driver supports only one-shot mode, and it can be
> > tested with reading from
> > /sys/bus/iio/devices/iio:deviceX/in_distance_raw
>
> Brief review for almost style issues...
>
> > + * vl53l0x-i2c.c - Support for STM VL53L0X FlightSense TOF
> > + * Ranger Sensor on a i2c bus.
>
> One line and without file name.
>
> > + *
> > + * Copyright (C) 2016 STMicroelectronics Imaging Division.
> > + * Copyright (C) 2018 Song Qiang <songqiang.1304521@xxxxxxxxx>
>
> > + *
>
> Redundant
>
> > + */
> > +
> > +#include <linux/module.h>
> > +#include <linux/slab.h>
> > +#include <linux/i2c.h>
> > +#include <linux/delay.h>
> > +#include <linux/kernel.h>
>
> Keep above sorted.
>
> > +#include <linux/iio/iio.h>
> > +
> > +#define VL53L0X_DRV_NAME "vl53l0x"
> > +
> > +/* Device register map */
> > +#define VL_REG_SYSRANGE_START 0x000
>
> 0x0000 ?
>
> > +#define VL_REG_SYSRANGE_MODE_MASK 0x0F
>
> GENMASK() ?
>
> > +#define VL_REG_SYSRANGE_MODE_START_STOP 0x01
> > +#define VL_REG_SYSRANGE_MODE_SINGLESHOT 0x00
> > +#define VL_REG_SYSRANGE_MODE_BACKTOBACK 0x02
> > +#define VL_REG_SYSRANGE_MODE_TIMED 0x04
> > +#define VL_REG_SYSRANGE_MODE_HISTOGRAM 0x08
>
> BIT() ?
>
> Above comments related to below definitions as well.
>
> > +
> > +#define VL_REG_SYS_THRESH_HIGH 0x000C
> > +#define VL_REG_SYS_THRESH_LOW 0x000E
> > +
> > +#define VL_REG_SYS_SEQUENCE_CFG 0x0001
> > +#define VL_REG_SYS_RANGE_CFG 0x0009
> > +#define VL_REG_SYS_INTERMEASUREMENT_PERIOD 0x0004
> > +
> > +#define VL_REG_SYS_INT_CFG_GPIO 0x000A
>
> If you chose 0xHHHH format for the registers, please, keep the list of them sorted by the offset / address.
>
> > +#define VL_REG_SYS_INT_GPIO_DISABLED 0x00
> > +#define VL_REG_SYS_INT_GPIO_LEVEL_LOW 0x01
> > +#define VL_REG_SYS_INT_GPIO_LEVEL_HIGH 0x02
> > +#define VL_REG_SYS_INT_GPIO_OUT_OF_WINDOW 0x03
> > +#define VL_REG_SYS_INT_GPIO_NEW_SAMPLE_READY 0x04
> > +#define VL_REG_GPIO_HV_MUX_ACTIVE_HIGH 0x0084
> > +#define VL_REG_SYS_INT_CLEAR 0x000B
> > +
> > +/* Result registers */
> > +#define VL_REG_RESULT_INT_STATUS 0x0013
> > +#define VL_REG_RESULT_RANGE_STATUS 0x0014
> > +
> > +#define VL_REG_RESULT_CORE_PAGE 1
> > +#define VL_REG_RESULT_CORE_AMBIENT_WINDOW_EVENTS_RTN 0x00BC
> > +#define VL_REG_RESULT_CORE_RANGING_TOTAL_EVENTS_RTN 0x00C0
> > +#define VL_REG_RESULT_CORE_AMBIENT_WINDOW_EVENTS_REF 0x00D0
> > +#define VL_REG_RESULT_CORE_RANGING_TOTAL_EVENTS_REF 0x00D4
> > +#define VL_REG_RESULT_PEAK_SIGNAL_RATE_REF 0x00B6
> > +
> > +/* Algo register */
> > +#define VL_REG_ALGO_PART_TO_PART_RANGE_OFFSET_MM 0x0028
> > +
> > +#define VL_REG_I2C_SLAVE_DEVICE_ADDRESS 0x008a
> > +
> > +/* Check Limit registers */
> > +#define VL_REG_MSRC_CFG_CONTROL 0x0060
> > +
> > +#define VL_REG_PRE_RANGE_CFG_MIN_SNR 0X0027
> > +#define VL_REG_PRE_RANGE_CFG_VALID_PHASE_LOW 0x0056
> > +#define VL_REG_PRE_RANGE_CFG_VALID_PHASE_HIGH 0x0057
> > +#define VL_REG_PRE_RANGE_MIN_COUNT_RATE_RTN_LIMIT 0x0064
> > +
> > +#define VL_REG_FINAL_RANGE_CFG_MIN_SNR 0X0067
> > +#define VL_REG_FINAL_RANGE_CFG_VALID_PHASE_LOW 0x0047
> > +#define VL_REG_FINAL_RANGE_CFG_VALID_PHASE_HIGH 0x0048
> > +#define VL_REG_FINAL_RANGE_CFG_MIN_COUNT_RATE_RTN_LIMIT 0x0044
> > +
>
> > +#define VL_REG_PRE_RANGE_CFG_SIGMA_THRESH_HI 0X0061
> > +#define VL_REG_PRE_RANGE_CFG_SIGMA_THRESH_LO 0X0062
>
> 0x
>
> > +
> > +/* PRE RANGE registers */
> > +#define VL_REG_PRE_RANGE_CFG_VCSEL_PERIOD 0x0050
> > +#define VL_REG_PRE_RANGE_CFG_TIMEOUT_MACROP_HI 0x0051
> > +#define VL_REG_PRE_RANGE_CFG_TIMEOUT_MACROP_LO 0x0052
> > +
> > +#define VL_REG_SYS_HISTOGRAM_BIN 0x0081
> > +#define VL_REG_HISTOGRAM_CFG_INITIAL_PHASE_SELECT 0x0033
> > +#define VL_REG_HISTOGRAM_CFG_READOUT_CTRL 0x0055
> > +
> > +#define VL_REG_FINAL_RANGE_CFG_VCSEL_PERIOD 0x0070
> > +#define VL_REG_FINAL_RANGE_CFG_TIMEOUT_MACROP_HI 0x0071
> > +#define VL_REG_FINAL_RANGE_CFG_TIMEOUT_MACROP_LO 0x0072
> > +#define VL_REG_CROSSTALK_COMPENSATION_PEAK_RATE_MCPS 0x0020
> > +
> > +#define VL_REG_MSRC_CFG_TIMEOUT_MACROP 0x0046
> > +
> > +#define VL_REG_SOFT_RESET_GO2_SOFT_RESET_N 0x00bf
> > +#define VL_REG_IDENTIFICATION_MODEL_ID 0x00c0
> > +#define VL_REG_IDENTIFICATION_REVISION_ID 0x00c2
> > +
> > +#define VL_REG_OSC_CALIBRATE_VAL 0x00f8
> > +
> > +#define VL_SIGMA_ESTIMATE_MAX_VALUE 65535
> > +/* equivalent to a range sigma of 655.35mm */
> > +
> > +#define VL_REG_GLOBAL_CFG_VCSEL_WIDTH 0x032
> > +#define VL_REG_GLOBAL_CFG_SPAD_ENABLES_REF_0 0x0B0
> > +#define VL_REG_GLOBAL_CFG_SPAD_ENABLES_REF_1 0x0B1
> > +#define VL_REG_GLOBAL_CFG_SPAD_ENABLES_REF_2 0x0B2
> > +#define VL_REG_GLOBAL_CFG_SPAD_ENABLES_REF_3 0x0B3
> > +#define VL_REG_GLOBAL_CFG_SPAD_ENABLES_REF_4 0x0B4
> > +#define VL_REG_GLOBAL_CFG_SPAD_ENABLES_REF_5 0x0B5
> > +#define VL_REG_GLOBAL_CFG_REF_EN_START_SELECT 0xB6
>
> 0x00 or 0x for prefix?
>
> > +#define VL_REG_DYNAMIC_SPAD_NUM_REQUESTED_REF_SPAD 0x4E /* 0x14E */
> > +#define VL_REG_DYNAMIC_SPAD_REF_EN_START_OFFSET 0x4F /* 0x14F */
> > +#define VL_REG_POWER_MANAGEMENT_GO1_POWER_FORCE 0x80
> > +
> > +/*
> > + * Speed of light in um per 1E-10 Seconds
> > + */
> > +#define VL_SPEED_OF_LIGHT_IN_AIR 2997
> > +#define VL_REG_VHV_CFG_PAD_SCL_SDA__EXTSUP_HV 0x0089
> > +#define VL_REG_ALGO_PHASECAL_LIM 0x0030 /* 0x130 */
> > +#define VL_REG_ALGO_PHASECAL_CFG_TIMEOUT 0x0030
> > +
> > +struct vl53l0x_data {
> > + struct i2c_client *client;
> > + struct mutex lock;
> > + int useLongRange;
>
> noCamelCasePlease.
>
> > +};
> > +
> > +static int vl53l0x_read_proximity(struct vl53l0x_data *data,
> > + const struct iio_chan_spec *chan,
> > + int *val)
> > +{
> > + int ret;
> > + struct i2c_client *client = data->client;
> > + int tries = 20;
>
> unsigned int
>
> > + u8 buffer[12];
> > + struct i2c_msg msg[2];
> > + u8 write_command = VL_REG_RESULT_RANGE_STATUS;
>
> Reversed xmas tree order, please
>
> > +
> > + ret = i2c_smbus_write_byte_data(data->client,
> > + VL_REG_SYSRANGE_START, 1);
> > + if (ret < 0)
> > + return ret;
> > +
> > + while (tries-- > 0) {
>
>
> Better form is
>
> do {
> ...
> } while (--tries);
> if (!tries)
> return -ETIMEDOUT;
>
> > + ret = i2c_smbus_read_byte_data(data->client,
> > + VL_REG_RESULT_RANGE_STATUS);
> > + if (ret < 0)
> > + return ret;
> > +
> > + if (ret & 0x01)
> > + break;
> > + usleep_range(1000, 5000);
> > + }
> > +
> > + if (tries < 0)
> > + return -ETIMEDOUT;
> > +
> > + msg[0].addr = client->addr;
> > + msg[0].buf = &write_command;
> > + msg[0].len = 1;
> > + msg[0].flags = client->flags | I2C_M_STOP;
> > +
> > + msg[1].addr = client->addr;
> > + msg[1].buf = buffer;
> > + msg[1].len = 12;
> > + msg[1].flags = client->flags | I2C_M_RD;
> > +
> > + ret = i2c_transfer(client->adapter, msg, 2);
> > +
>
> > + if (ret != 2) {
>
> Shouldn't be simple if (ret < 0)
>
> > + pr_err("vl53l0x: consecutively read error. ");
>
> dev_err(...);
> Also check other prints.
>
> > + return ret;
> > + }
> > +
> > + *val = __le16_to_cpu((buffer[10] << 8) + buffer[11]);
> > +
> > + return 0;
> > +}
>
> > +static int vl53l0x_probe(struct i2c_client *client,
> > + const struct i2c_device_id *id)
>
> (see below about ->probe_new() hook)
>
> > +{
> > + int ret;
> > + struct vl53l0x_data *data;
> > + struct iio_dev *indio_dev;
> > +
> > + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
> > + if (!indio_dev)
> > + return -ENOMEM;
> > +
> > + data = iio_priv(indio_dev);
> > + data->client = client;
> > + i2c_set_clientdata(client, indio_dev);
> > + mutex_init(&data->lock);
> > +
> > + if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE))
> > + return -EOPNOTSUPP;
> > +
> > + indio_dev->dev.parent = &client->dev;
> > + indio_dev->name = VL53L0X_DRV_NAME;
> > + indio_dev->info = &vl53l0x_info;
> > + indio_dev->channels = vl53l0x_channels;
> > + indio_dev->num_channels = ARRAY_SIZE(vl53l0x_channels);
> > + indio_dev->modes = INDIO_DIRECT_MODE;
> > +
>
> > + //probe 0xc0 if the value is 0xEE.
>
> Useless commwnt for now
>
> > +
> > + ret = iio_device_register(indio_dev);
> > + if (ret)
> > + return ret;
> > +
> > + dev_set_drvdata(&client->dev, data);
> > +
> > + return 0;
> > +}
> > +
> > +static int vl53l0x_remove(struct i2c_client *client)
> > +{
> > + struct iio_dev *indio_dev = i2c_get_clientdata(client);
> > + struct vl53l0x_data *data = iio_priv(indio_dev);
> > +
> > + iio_device_unregister(indio_dev);
>
> > + kfree(data);
>
> how did you test it?
>
> > +
> > + return 0;
> > +}
> > +
> > +static const struct i2c_device_id vl53l0x_id[] = {
> > + { VL53L0X_DRV_NAME, 0 },
>
> > + { },
> Terminator better w/o comma
>
> > +};
> > +MODULE_DEVICE_TABLE(i2c, vl53l0x_id);
>
> Do you expect this to be used at all?
>
> > +
> > +static const struct of_device_id st_vl53l0x_dt_match[] = {
> > + { .compatible = "st,vl53l0x-i2c", },
>
> > + { },
>
> Terminator better w/o comma
>
> > +};
> > +
> > +static struct i2c_driver vl53l0x_driver = {
> > + .driver = {
> > + .name = VL53L0X_DRV_NAME,
>
> > + .owner = THIS_MODULE,
>
> This done by macro.
>
> > + .of_match_table = st_vl53l0x_dt_match,
> > + },
> > + .probe = vl53l0x_probe,
>
> ->probe_new(), please.
>
> > + .remove = vl53l0x_remove,
> > + .id_table = vl53l0x_id,
> > +};
> > +module_i2c_driver(vl53l0x_driver);
> > +
> > +MODULE_AUTHOR("Song Qiang <songqiang.1304521@xxxxxxxxx>");
> > +MODULE_DESCRIPTION("ST vl53l0x ToF ranging sensor");
> > +MODULE_LICENSE("GPL");
> > --
> > 2.17.1
> >
>
> --
> With Best Regards,
> Andy Shevchenko
>
>
Hi Andy,
Sorry for the mess in register table, I took it from ST's
API and has only checked it with the checkpatch.pl.
I didn't know about probe_new() when I was writing this driver,
I'll see what it does and try to use it.
I'll check the other problems you listed and clean up the
register table.
Thanks a lot for the reviewing.
Yours,
Song Qiang