| Message ID | 20180915095752.8116-1-songqiang.1304521@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v5] iio: proximity: Add driver support for ST's VL53L0X ToF ranging sensor. | expand |
On Sat, 15 Sep 2018 17:57:52 +0800 Song Qiang <songqiang1304521@gmail.com> wrote: > This driver was originally written by ST in 2016 as a misc input device > driver, and hasn't been maintained for a long time. I grabbed some code > from it's API and reformed it into an 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 > > Signed-off-by: Song Qiang <songqiang.1304521@gmail.com> Hi Song, My first comment was going to be don't use wild cards in a part name in a driver, but a quick sanity check confirmed that ST were actually crazy enough to end a part number with an X. Ah well ;) Otherwise a few minor things, mostly around naming. There is some confusion around endian stuff as well Looks pretty good for a first go at upstreaming a driver! Are you planning on adding more features? Seems like a capable little device and would be good to have fuller support in the long term if you have time to look at it! Jonathan > --- > Changes in v5: > - Correct some spell problems. > - Change tries-- to --tries to fix the count error. > - Add MODULE_DEVICE_TABLE(). > - Add some comments. > > Changes in v4: > - Add datasheet link, default i2c address and TODO list. > - Make capitalization of defines consistent. > - Replace i2c_transfer() with i2c_smbus_read_i2c_block_data(). > - Remove IIO_CHAN_SOFT_TIMESTAMP() since no buffer/trigger > support. > - Add information to MAINTAINERS. > > Changes in v3: > - Recover ST's copyright. > - Clean up indio_dev member in vl53l0x_data struct since it's > useless now. > - Replace __le16_to_cpu() with le16_to_cpu(). > - Remove the iio_device_{claim|release}_direct_mode() since it's > only needed when we use buffered mode. > - Clean up some coding style problems. > > Changes in v2: > - Clean up the register table. > - Sort header files declarations. > - Replace some bit definations with GENMASK() and BIT(). > - Clean up some code and comments that's useless for now. > - Change the order of some the definations of some variables to reversed > xmas tree order. > - Using do...while() rather while and check. > - Replace pr_err() with dev_err(). > - Remove device id declaration since we recommend to use DT. > - Remove .owner = THIS_MODULE. > - Replace probe() with probe_new() hook. > - Remove IIO_BUFFER and IIO_TRIGGERED_BUFFER dependences. > - Change the driver module name to vl53l0x-i2c. > - Align all the parameters if they are in the same function with open > parentheses. > - Replace iio_device_register() with devm_iio_device_register > for better resource management. > - Remove the vl53l0x_remove() since it's not needed. > - Remove dev_set_drvdata() since it's already setted above. > > .../bindings/iio/proximity/vl53l0x.txt | 12 ++ > MAINTAINERS | 7 + > drivers/iio/proximity/Kconfig | 11 ++ > drivers/iio/proximity/Makefile | 2 + > drivers/iio/proximity/vl53l0x-i2c.c | 180 ++++++++++++++++++ > 5 files changed, 212 insertions(+) > create mode 100644 Documentation/devicetree/bindings/iio/proximity/vl53l0x.txt > create mode 100644 drivers/iio/proximity/vl53l0x-i2c.c > > diff --git a/Documentation/devicetree/bindings/iio/proximity/vl53l0x.txt b/Documentation/devicetree/bindings/iio/proximity/vl53l0x.txt > new file mode 100644 > index 000000000000..ab9a9539fec4 > --- /dev/null > +++ b/Documentation/devicetree/bindings/iio/proximity/vl53l0x.txt > @@ -0,0 +1,12 @@ > +ST VL53L0X ToF ranging sensor > + > +Required properties: > + - compatible: must be "st,vl53l0x-i2c" > + - reg: i2c address where to find the device > + > +Example: > + > +vl53l0x@29 { > + compatible = "st,vl53l0x-i2c"; > + reg = <0x29>; > +}; > diff --git a/MAINTAINERS b/MAINTAINERS > index 967ce8cdd1cc..a35d80e63506 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -13510,6 +13510,13 @@ L: linux-i2c@vger.kernel.org > S: Maintained > F: drivers/i2c/busses/i2c-stm32* > > +ST VL53L0X ToF RANGER(I2C) IIO DRIVER > +M: Song Qiang <songqiang.1304521@gmail.com> > +L: linux-iio@vger.kernel.org > +S: Maintained > +F: drivers/iio/proximity/vl53l0x-i2c.c > +F: Documentation/devicetree/bindings/iio/proximity/vl53l0x.txt > + > STABLE BRANCH > M: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > L: stable@vger.kernel.org > diff --git a/drivers/iio/proximity/Kconfig b/drivers/iio/proximity/Kconfig > index f726f9427602..5f421cbd37f3 100644 > --- a/drivers/iio/proximity/Kconfig > +++ b/drivers/iio/proximity/Kconfig > @@ -79,4 +79,15 @@ config SRF08 > To compile this driver as a module, choose M here: the > module will be called srf08. > > +config VL53L0X_I2C > + tristate "STMicroelectronics VL53L0X ToF ranger sensor (I2C)" > + depends on I2C > + help > + Say Y here to build a driver for STMicroelectronics VL53L0X > + ToF ranger sensors with i2c interface. > + This driver can be used to measure the distance of objects. > + > + To compile this driver as a module, choose M here: the > + module will be called vl53l0x-i2c. > + > endmenu > diff --git a/drivers/iio/proximity/Makefile b/drivers/iio/proximity/Makefile > index 4f4ed45e87ef..dedfb5bf3475 100644 > --- a/drivers/iio/proximity/Makefile > +++ b/drivers/iio/proximity/Makefile > @@ -10,3 +10,5 @@ obj-$(CONFIG_RFD77402) += rfd77402.o > obj-$(CONFIG_SRF04) += srf04.o > obj-$(CONFIG_SRF08) += srf08.o > obj-$(CONFIG_SX9500) += sx9500.o > +obj-$(CONFIG_VL53L0X_I2C) += vl53l0x-i2c.o > + > diff --git a/drivers/iio/proximity/vl53l0x-i2c.c b/drivers/iio/proximity/vl53l0x-i2c.c > new file mode 100644 > index 000000000000..4837cc2fff19 > --- /dev/null > +++ b/drivers/iio/proximity/vl53l0x-i2c.c > @@ -0,0 +1,180 @@ > +// SPDX-License-Identifier: GPL-2.0+ > +/* > + * Support for ST VL53L0X FlightSense ToF Ranging Sensor on a i2c bus. > + * > + * Copyright (C) 2016 STMicroelectronics Imaging Division. > + * Copyright (C) 2018 Song Qiang <songqiang.1304521@gmail.com> > + * > + * Datasheet available at > + * <https://www.st.com/resource/en/datasheet/vl53l0x.pdf> > + * > + * Default 7-bit i2c slave address 0x29. > + * > + * TODO: FIFO buffer, continuous mode, interrupts, range selection, > + * sensor ID check. > + */ > + > +#include <linux/module.h> > +#include <linux/i2c.h> > +#include <linux/delay.h> > + > +#include <linux/iio/iio.h> > + > +#define VL53L0X_DRV_NAME "vl53l0x-i2c" A quick google suggests this only has an i2c interface. Hence I'd argue there is no point in having -i2c in the driver name. Lots of other i2c only parts don't on the basis it doesn't add anything. In fact the only time we tend to do this is if we have a driver that splits into a shared core and two or more bus specific drivers. > + > +#define VL_REG_SYSRANGE_START 0x00 > + > +#define VL_REG_SYSRANGE_MODE_MASK GENMASK(3, 0) > +#define VL_REG_SYSRANGE_MODE_SINGLESHOT 0x00 > +#define VL_REG_SYSRANGE_MODE_START_STOP BIT(0) > +#define VL_REG_SYSRANGE_MODE_BACKTOBACK BIT(1) > +#define VL_REG_SYSRANGE_MODE_TIMED BIT(2) > +#define VL_REG_SYSRANGE_MODE_HISTOGRAM BIT(3) > + > +#define VL_REG_SYS_SEQUENCE_CFG BIT(0) > +#define VL_REG_SYS_INTERMEASUREMENT_PERIOD BIT(2) > +#define VL_REG_SYS_RANGE_CFG 0x09 > +#define VL_REG_SYS_INT_GPIO_DISABLED 0x00 > +#define VL_REG_SYS_INT_GPIO_LEVEL_LOW BIT(0) > +#define VL_REG_SYS_INT_GPIO_LEVEL_HIGH BIT(1) > +#define VL_REG_SYS_INT_GPIO_OUT_OF_WINDOW 0x03 > +#define VL_REG_SYS_INT_GPIO_NEW_SAMPLE_READY BIT(2) > +#define VL_REG_SYS_INT_CFG_GPIO 0x0A > +#define VL_REG_SYS_INT_CLEAR 0x0B > +#define VL_REG_GPIO_HV_MUX_ACTIVE_HIGH 0x84 > + > +#define VL_REG_RESULT_INT_STATUS 0x13 > +#define VL_REG_RESULT_RANGE_STATUS 0x14 > +#define VL_REG_RESULT_RANGE_STATUS_COMPLETE BIT(0) > + > +/* Check contents of these registers to verify the device. */ > +#define VL_REG_IDENTIFICATION_MODEL_ID 0xC0 > +#define VL_REG_IDENTIFICATION_REVISION_ID 0xC2 > + > +struct vl53l0x_data { > + struct i2c_client *client; > +}; > + > +static int vl53l0x_read_proximity(struct vl53l0x_data *data, > + const struct iio_chan_spec *chan, > + int *val) > +{ > + struct i2c_client *client = data->client; > + unsigned int tries = 20; > + u8 buffer[12]; > + int ret; > + > + ret = i2c_smbus_write_byte_data(client, > + VL_REG_SYSRANGE_START, 1); Looks like the above would fit on one line. Please do a quick check through the driver for other cases of this. > + if (ret < 0) > + return ret; > + > + do { > + ret = i2c_smbus_read_byte_data(client, > + VL_REG_RESULT_RANGE_STATUS); > + if (ret < 0) > + return ret; > + > + if (ret & VL_REG_RESULT_RANGE_STATUS_COMPLETE) > + break; > + > + usleep_range(1000, 5000); > + } while (--tries); > + if (!tries) > + return -ETIMEDOUT; > + > + ret = i2c_smbus_read_i2c_block_data(client, VL_REG_RESULT_RANGE_STATUS, > + 12, buffer); > + if (ret < 0) > + return ret; > + else if (ret != 12) > + return -EREMOTEIO; > + > + /* Values should be between 30~1200. */ > + *val = le16_to_cpu((buffer[10] << 8) + buffer[11]); This worries me as a conversion. The shift and addition is unwinding the endianness already. You then do it again with le16_to_cpu As it's aligned you could have done *val = le16_to_cpu(*(le16 *)(&buffer[10])); That's obviously a bit ugly though, mainly because we are handling the buffer as a u8. Is there a reason to not directly handle it as an le16 array? I'm having trouble finding the relevant section of the manual to actually figure out what is in the first 10 bytes! > + > + return 0; > +} > + > +static const struct iio_chan_spec vl53l0x_channels[] = { > + { > + .type = IIO_DISTANCE, > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), This is a time of flight sensor? As such I would kind of assume it is possible to get to a real world distance? Adding scale and offset to do this can of course be a follow up patch, but it would be good to have! > + }, > +}; > + > +static int vl53l0x_read_raw(struct iio_dev *indio_dev, > + const struct iio_chan_spec *chan, > + int *val, int *val2, long mask) > +{ > + struct vl53l0x_data *data = iio_priv(indio_dev); > + int ret; > + > + if (chan->type != IIO_DISTANCE) { > + dev_err(&data->client->dev, "iio type error"); This can't actually happen as there are no other channel types registered. The if check is really a form of documentation rather than real protection. As such I'd drop the dev_err print out as unnecessary noise. A simple return -EINVAL is more than enough here. > + return -EINVAL; > + } > + > + switch (mask) { > + case IIO_CHAN_INFO_RAW: > + ret = vl53l0x_read_proximity(data, chan, val); > + if (ret < 0) > + dev_err(&data->client->dev, > + "raw value read error with %d", ret); If return is less than 0 you should be passing that on to userspace (so add a return ret in this if block.) > + > + return IIO_VAL_INT; > + default: > + dev_err(&data->client->dev, "IIO_CHAN_* not recognized."); > + return -EINVAL; > + } > +} > + > +static const struct iio_info vl53l0x_info = { > + .read_raw = vl53l0x_read_raw, > +}; > + > +static int vl53l0x_probe(struct i2c_client *client) > +{ > + 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); > + > + if (!i2c_check_functionality(client->adapter, > + I2C_FUNC_SMBUS_READ_I2C_BLOCK | I2C_FUNC_SMBUS_BYTE_DATA)) > + 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; > + > + return devm_iio_device_register(&client->dev, indio_dev); > +} > + > +static const struct of_device_id st_vl53l0x_dt_match[] = { > + { .compatible = "st,vl53l0x-i2c", }, Compatible shouldn't need the -i2c as it will only check for i2c devices if they are on an i2c bus anyway. > + { } > +}; > +MODULE_DEVICE_TABLE(of, st_vl53l0x_dt_match); > + > +static struct i2c_driver vl53l0x_driver = { > + .driver = { > + .name = VL53L0X_DRV_NAME, > + .of_match_table = st_vl53l0x_dt_match, > + }, > + .probe_new = vl53l0x_probe, > +}; > +module_i2c_driver(vl53l0x_driver); > + > +MODULE_AUTHOR("Song Qiang <songqiang.1304521@gmail.com>"); > +MODULE_DESCRIPTION("ST vl53l0x ToF ranging sensor driver"); > +MODULE_LICENSE("GPL v2");
On Sun, Sep 16, 2018 at 12:01:49PM +0100, Jonathan Cameron wrote: > On Sat, 15 Sep 2018 17:57:52 +0800 > Song Qiang <songqiang1304521@gmail.com> wrote: > > > This driver was originally written by ST in 2016 as a misc input device > > driver, and hasn't been maintained for a long time. I grabbed some code > > from it's API and reformed it into an 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 > > > > Signed-off-by: Song Qiang <songqiang.1304521@gmail.com> > Hi Song, > > My first comment was going to be don't use wild cards in a part name > in a driver, but a quick sanity check confirmed that ST were actually > crazy enough to end a part number with an X. Ah well ;) > > Otherwise a few minor things, mostly around naming. There is some > confusion around endian stuff as well > > Looks pretty good for a first go at upstreaming a driver! > > Are you planning on adding more features? Seems like a capable little device > and would be good to have fuller support in the long term if you have time > to look at it! > > Jonathan > Hi Jonathan, Thanks for spending time with my patch! Since I'm now just a student and intrested in embedded linux very much, there are plenty of free time for me to work on this, and working with the community is not only interesting but helpful to my knowledge. People reviewed my patch gave me a lot helpful suggestions, espacially Himanshu. :) When I was writing this patch, I thought maybe I should go one step each time, so this driver may seems like a little simple, but I believe it's just for now. Actually there is a question, ST released a new version of this device called VL53L1X in June, which still has no support for linux drivers, but compitable with VL53L0X. Do you have any suggestions for my driver's name? The first one came to my mind would be VL53LxX, which is a little crazy I think. ;) > > --- > > Changes in v5: > > - Correct some spell problems. > > - Change tries-- to --tries to fix the count error. > > - Add MODULE_DEVICE_TABLE(). > > - Add some comments. > > > > Changes in v4: > > - Add datasheet link, default i2c address and TODO list. > > - Make capitalization of defines consistent. > > - Replace i2c_transfer() with i2c_smbus_read_i2c_block_data(). > > - Remove IIO_CHAN_SOFT_TIMESTAMP() since no buffer/trigger > > support. > > - Add information to MAINTAINERS. > > > > Changes in v3: > > - Recover ST's copyright. > > - Clean up indio_dev member in vl53l0x_data struct since it's > > useless now. > > - Replace __le16_to_cpu() with le16_to_cpu(). > > - Remove the iio_device_{claim|release}_direct_mode() since it's > > only needed when we use buffered mode. > > - Clean up some coding style problems. > > > > Changes in v2: > > - Clean up the register table. > > - Sort header files declarations. > > - Replace some bit definations with GENMASK() and BIT(). > > - Clean up some code and comments that's useless for now. > > - Change the order of some the definations of some variables to reversed > > xmas tree order. > > - Using do...while() rather while and check. > > - Replace pr_err() with dev_err(). > > - Remove device id declaration since we recommend to use DT. > > - Remove .owner = THIS_MODULE. > > - Replace probe() with probe_new() hook. > > - Remove IIO_BUFFER and IIO_TRIGGERED_BUFFER dependences. > > - Change the driver module name to vl53l0x-i2c. > > - Align all the parameters if they are in the same function with open > > parentheses. > > - Replace iio_device_register() with devm_iio_device_register > > for better resource management. > > - Remove the vl53l0x_remove() since it's not needed. > > - Remove dev_set_drvdata() since it's already setted above. > > > > .../bindings/iio/proximity/vl53l0x.txt | 12 ++ > > MAINTAINERS | 7 + > > drivers/iio/proximity/Kconfig | 11 ++ > > drivers/iio/proximity/Makefile | 2 + > > drivers/iio/proximity/vl53l0x-i2c.c | 180 ++++++++++++++++++ > > 5 files changed, 212 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/iio/proximity/vl53l0x.txt > > create mode 100644 drivers/iio/proximity/vl53l0x-i2c.c > > > > diff --git a/Documentation/devicetree/bindings/iio/proximity/vl53l0x.txt b/Documentation/devicetree/bindings/iio/proximity/vl53l0x.txt > > new file mode 100644 > > index 000000000000..ab9a9539fec4 > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/iio/proximity/vl53l0x.txt > > @@ -0,0 +1,12 @@ > > +ST VL53L0X ToF ranging sensor > > + > > +Required properties: > > + - compatible: must be "st,vl53l0x-i2c" > > + - reg: i2c address where to find the device > > + > > +Example: > > + > > +vl53l0x@29 { > > + compatible = "st,vl53l0x-i2c"; > > + reg = <0x29>; > > +}; > > diff --git a/MAINTAINERS b/MAINTAINERS > > index 967ce8cdd1cc..a35d80e63506 100644 > > --- a/MAINTAINERS > > +++ b/MAINTAINERS > > @@ -13510,6 +13510,13 @@ L: linux-i2c@vger.kernel.org > > S: Maintained > > F: drivers/i2c/busses/i2c-stm32* > > > > +ST VL53L0X ToF RANGER(I2C) IIO DRIVER > > +M: Song Qiang <songqiang.1304521@gmail.com> > > +L: linux-iio@vger.kernel.org > > +S: Maintained > > +F: drivers/iio/proximity/vl53l0x-i2c.c > > +F: Documentation/devicetree/bindings/iio/proximity/vl53l0x.txt > > + > > STABLE BRANCH > > M: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > > L: stable@vger.kernel.org > > diff --git a/drivers/iio/proximity/Kconfig b/drivers/iio/proximity/Kconfig > > index f726f9427602..5f421cbd37f3 100644 > > --- a/drivers/iio/proximity/Kconfig > > +++ b/drivers/iio/proximity/Kconfig > > @@ -79,4 +79,15 @@ config SRF08 > > To compile this driver as a module, choose M here: the > > module will be called srf08. > > > > +config VL53L0X_I2C > > + tristate "STMicroelectronics VL53L0X ToF ranger sensor (I2C)" > > + depends on I2C > > + help > > + Say Y here to build a driver for STMicroelectronics VL53L0X > > + ToF ranger sensors with i2c interface. > > + This driver can be used to measure the distance of objects. > > + > > + To compile this driver as a module, choose M here: the > > + module will be called vl53l0x-i2c. > > + > > endmenu > > diff --git a/drivers/iio/proximity/Makefile b/drivers/iio/proximity/Makefile > > index 4f4ed45e87ef..dedfb5bf3475 100644 > > --- a/drivers/iio/proximity/Makefile > > +++ b/drivers/iio/proximity/Makefile > > @@ -10,3 +10,5 @@ obj-$(CONFIG_RFD77402) += rfd77402.o > > obj-$(CONFIG_SRF04) += srf04.o > > obj-$(CONFIG_SRF08) += srf08.o > > obj-$(CONFIG_SX9500) += sx9500.o > > +obj-$(CONFIG_VL53L0X_I2C) += vl53l0x-i2c.o > > + > > diff --git a/drivers/iio/proximity/vl53l0x-i2c.c b/drivers/iio/proximity/vl53l0x-i2c.c > > new file mode 100644 > > index 000000000000..4837cc2fff19 > > --- /dev/null > > +++ b/drivers/iio/proximity/vl53l0x-i2c.c > > @@ -0,0 +1,180 @@ > > +// SPDX-License-Identifier: GPL-2.0+ > > +/* > > + * Support for ST VL53L0X FlightSense ToF Ranging Sensor on a i2c bus. > > + * > > + * Copyright (C) 2016 STMicroelectronics Imaging Division. > > + * Copyright (C) 2018 Song Qiang <songqiang.1304521@gmail.com> > > + * > > + * Datasheet available at > > + * <https://www.st.com/resource/en/datasheet/vl53l0x.pdf> > > + * > > + * Default 7-bit i2c slave address 0x29. > > + * > > + * TODO: FIFO buffer, continuous mode, interrupts, range selection, > > + * sensor ID check. > > + */ > > + > > +#include <linux/module.h> > > +#include <linux/i2c.h> > > +#include <linux/delay.h> > > + > > +#include <linux/iio/iio.h> > > + > > +#define VL53L0X_DRV_NAME "vl53l0x-i2c" > > A quick google suggests this only has an i2c interface. Hence I'd argue > there is no point in having -i2c in the driver name. Lots of other > i2c only parts don't on the basis it doesn't add anything. In fact > the only time we tend to do this is if we have a driver that splits > into a shared core and two or more bus specific drivers. > Actually this device do has a CCI(Camera Control Interface) for communication and it's original API has two kinds of ways for accessing this device. > > + > > +#define VL_REG_SYSRANGE_START 0x00 > > + > > +#define VL_REG_SYSRANGE_MODE_MASK GENMASK(3, 0) > > +#define VL_REG_SYSRANGE_MODE_SINGLESHOT 0x00 > > +#define VL_REG_SYSRANGE_MODE_START_STOP BIT(0) > > +#define VL_REG_SYSRANGE_MODE_BACKTOBACK BIT(1) > > +#define VL_REG_SYSRANGE_MODE_TIMED BIT(2) > > +#define VL_REG_SYSRANGE_MODE_HISTOGRAM BIT(3) > > + > > +#define VL_REG_SYS_SEQUENCE_CFG BIT(0) > > +#define VL_REG_SYS_INTERMEASUREMENT_PERIOD BIT(2) > > +#define VL_REG_SYS_RANGE_CFG 0x09 > > +#define VL_REG_SYS_INT_GPIO_DISABLED 0x00 > > +#define VL_REG_SYS_INT_GPIO_LEVEL_LOW BIT(0) > > +#define VL_REG_SYS_INT_GPIO_LEVEL_HIGH BIT(1) > > +#define VL_REG_SYS_INT_GPIO_OUT_OF_WINDOW 0x03 > > +#define VL_REG_SYS_INT_GPIO_NEW_SAMPLE_READY BIT(2) > > +#define VL_REG_SYS_INT_CFG_GPIO 0x0A > > +#define VL_REG_SYS_INT_CLEAR 0x0B > > +#define VL_REG_GPIO_HV_MUX_ACTIVE_HIGH 0x84 > > + > > +#define VL_REG_RESULT_INT_STATUS 0x13 > > +#define VL_REG_RESULT_RANGE_STATUS 0x14 > > +#define VL_REG_RESULT_RANGE_STATUS_COMPLETE BIT(0) > > + > > +/* Check contents of these registers to verify the device. */ > > +#define VL_REG_IDENTIFICATION_MODEL_ID 0xC0 > > +#define VL_REG_IDENTIFICATION_REVISION_ID 0xC2 > > + > > +struct vl53l0x_data { > > + struct i2c_client *client; > > +}; > > + > > +static int vl53l0x_read_proximity(struct vl53l0x_data *data, > > + const struct iio_chan_spec *chan, > > + int *val) > > +{ > > + struct i2c_client *client = data->client; > > + unsigned int tries = 20; > > + u8 buffer[12]; > > + int ret; > > + > > + ret = i2c_smbus_write_byte_data(client, > > + VL_REG_SYSRANGE_START, 1); > > Looks like the above would fit on one line. Please do a quick check > through the driver for other cases of this. > Oops, I'll change that. > > + if (ret < 0) > > + return ret; > > + > > + do { > > + ret = i2c_smbus_read_byte_data(client, > > + VL_REG_RESULT_RANGE_STATUS); > > + if (ret < 0) > > + return ret; > > + > > + if (ret & VL_REG_RESULT_RANGE_STATUS_COMPLETE) > > + break; > > + > > + usleep_range(1000, 5000); > > + } while (--tries); > > + if (!tries) > > + return -ETIMEDOUT; > > + > > + ret = i2c_smbus_read_i2c_block_data(client, VL_REG_RESULT_RANGE_STATUS, > > + 12, buffer); > > + if (ret < 0) > > + return ret; > > + else if (ret != 12) > > + return -EREMOTEIO; > > + > > + /* Values should be between 30~1200. */ > > + *val = le16_to_cpu((buffer[10] << 8) + buffer[11]); > This worries me as a conversion. The shift and addition is > unwinding the endianness already. You then do it again with le16_to_cpu > > As it's aligned you could have done > *val = le16_to_cpu(*(le16 *)(&buffer[10])); That's obviously > a bit ugly though, mainly because we are handling the buffer as > a u8. Is there a reason to not directly handle it as an le16 array? > > I'm having trouble finding the relevant section of the manual to actually > figure out what is in the first 10 bytes! > > > Sorry for this insanity, actually, I was writing this driver without a full memory layout. I tried to look for one, but then I found the poor ST support seems like doesn't want to release one at all! Have a look at this thread on Soren Karlsen's reply: <https://community.st.com/s/question/0D50X00009XkYTtSAN/request-of-vl53l0x> All those documents on ST's support websites mentioned only several registers for connection check. I can't say this is a very big deal because at least ST released a full API source with documentation. I analyzed their API source and also looked up some usage examples on google to get this device working. The protocal in the datasheet P19-20 shows that this device has to read consecutive bytes stream to get all data. I tried to access these registers one by one but it's not working. Datasheet: <https://www.st.com/resource/en/datasheet/vl53l0x.pdf> P19-20 Something I know from arduino's example code is that the 11th and 12th bytes hold distance, the 9th and 10th bytes hold signal countdown value and 7th and 8th bytes hold ambient countdown value. > > + > > + return 0; > > +} > > + > > +static const struct iio_chan_spec vl53l0x_channels[] = { > > + { > > + .type = IIO_DISTANCE, > > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), > > This is a time of flight sensor? As such I would kind of assume it is possible > to get to a real world distance? Adding scale and offset to do this can > of course be a follow up patch, but it would be good to have! > That's right, there was a scale channel, but since this device returns value in millimeters I thought there isn't a need for that channel, so I just return raw value. Usually in our production, we do some linear calibration for it's return values, but I think this may should be left with userspace to do. > > + }, > > +}; > > + > > +static int vl53l0x_read_raw(struct iio_dev *indio_dev, > > + const struct iio_chan_spec *chan, > > + int *val, int *val2, long mask) > > +{ > > + struct vl53l0x_data *data = iio_priv(indio_dev); > > + int ret; > > + > > + if (chan->type != IIO_DISTANCE) { > > + dev_err(&data->client->dev, "iio type error"); > > This can't actually happen as there are no other channel types > registered. The if check is really a form of documentation rather > than real protection. As such I'd drop the dev_err print > out as unnecessary noise. A simple return -EINVAL is more than > enough here. > I'll remove that. > > + return -EINVAL; > > + } > > + > > + switch (mask) { > > + case IIO_CHAN_INFO_RAW: > > + ret = vl53l0x_read_proximity(data, chan, val); > > + if (ret < 0) > > + dev_err(&data->client->dev, > > + "raw value read error with %d", ret); > > If return is less than 0 you should be passing that on to userspace > (so add a return ret in this if block.) > Okay. > > + > > + return IIO_VAL_INT; > > + default: > > + dev_err(&data->client->dev, "IIO_CHAN_* not recognized."); > > + return -EINVAL; > > + } > > +} > > + > > +static const struct iio_info vl53l0x_info = { > > + .read_raw = vl53l0x_read_raw, > > +}; > > + > > +static int vl53l0x_probe(struct i2c_client *client) > > +{ > > + 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); > > + > > + if (!i2c_check_functionality(client->adapter, > > + I2C_FUNC_SMBUS_READ_I2C_BLOCK | I2C_FUNC_SMBUS_BYTE_DATA)) > > + 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; > > + > > + return devm_iio_device_register(&client->dev, indio_dev); > > +} > > + > > +static const struct of_device_id st_vl53l0x_dt_match[] = { > > + { .compatible = "st,vl53l0x-i2c", }, > > Compatible shouldn't need the -i2c as it will only check for > i2c devices if they are on an i2c bus anyway. > There is another inferface as I mentioned above. > > + { } > > +}; > > +MODULE_DEVICE_TABLE(of, st_vl53l0x_dt_match); > > + > > +static struct i2c_driver vl53l0x_driver = { > > + .driver = { > > + .name = VL53L0X_DRV_NAME, > > + .of_match_table = st_vl53l0x_dt_match, > > + }, > > + .probe_new = vl53l0x_probe, > > +}; > > +module_i2c_driver(vl53l0x_driver); > > + > > +MODULE_AUTHOR("Song Qiang <songqiang.1304521@gmail.com>"); > > +MODULE_DESCRIPTION("ST vl53l0x ToF ranging sensor driver"); > > +MODULE_LICENSE("GPL v2"); > Yours, Song Qiang
On Sat, Sep 15, 2018 at 05:57:52PM +0800, Song Qiang wrote: > This driver was originally written by ST in 2016 as a misc input device > driver, and hasn't been maintained for a long time. I grabbed some code > from it's API and reformed it into an 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 > > Signed-off-by: Song Qiang <songqiang.1304521@gmail.com> checkpatch.pl complains that the author and signoff emails don't match. I think gmail ignores '.' in email names, but better to be consistent IMO. > --- > Changes in v5: > - Correct some spell problems. > - Change tries-- to --tries to fix the count error. > - Add MODULE_DEVICE_TABLE(). > - Add some comments. > > Changes in v4: > - Add datasheet link, default i2c address and TODO list. > - Make capitalization of defines consistent. > - Replace i2c_transfer() with i2c_smbus_read_i2c_block_data(). > - Remove IIO_CHAN_SOFT_TIMESTAMP() since no buffer/trigger > support. > - Add information to MAINTAINERS. > > Changes in v3: > - Recover ST's copyright. > - Clean up indio_dev member in vl53l0x_data struct since it's > useless now. > - Replace __le16_to_cpu() with le16_to_cpu(). > - Remove the iio_device_{claim|release}_direct_mode() since it's > only needed when we use buffered mode. > - Clean up some coding style problems. > > Changes in v2: > - Clean up the register table. > - Sort header files declarations. > - Replace some bit definations with GENMASK() and BIT(). > - Clean up some code and comments that's useless for now. > - Change the order of some the definations of some variables to reversed > xmas tree order. > - Using do...while() rather while and check. > - Replace pr_err() with dev_err(). > - Remove device id declaration since we recommend to use DT. > - Remove .owner = THIS_MODULE. > - Replace probe() with probe_new() hook. > - Remove IIO_BUFFER and IIO_TRIGGERED_BUFFER dependences. > - Change the driver module name to vl53l0x-i2c. > - Align all the parameters if they are in the same function with open > parentheses. > - Replace iio_device_register() with devm_iio_device_register > for better resource management. > - Remove the vl53l0x_remove() since it's not needed. > - Remove dev_set_drvdata() since it's already setted above. > > .../bindings/iio/proximity/vl53l0x.txt | 12 ++ > MAINTAINERS | 7 + Otherwise, Reviewed-by: Rob Herring <robh@kernel.org> > drivers/iio/proximity/Kconfig | 11 ++ > drivers/iio/proximity/Makefile | 2 + > drivers/iio/proximity/vl53l0x-i2c.c | 180 ++++++++++++++++++ > 5 files changed, 212 insertions(+) > create mode 100644 Documentation/devicetree/bindings/iio/proximity/vl53l0x.txt > create mode 100644 drivers/iio/proximity/vl53l0x-i2c.c
On Mon, Sep 17, 2018 at 02:19:33AM -0400, Rob Herring wrote: > On Sat, Sep 15, 2018 at 05:57:52PM +0800, Song Qiang wrote: > > This driver was originally written by ST in 2016 as a misc input device > > driver, and hasn't been maintained for a long time. I grabbed some code > > from it's API and reformed it into an 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 > > > > Signed-off-by: Song Qiang <songqiang.1304521@gmail.com> > > checkpatch.pl complains that the author and signoff emails don't match. > I think gmail ignores '.' in email names, but better to be consistent > IMO. > Hi Rob, This isn't the first time I've seen this '.' issue, but in most case it was fine. The thing interesting is after I saw your email, I tried to access my account with songqiang1304521@gmail.com(just without '.'), and it succeeded! So maybe google just removed the '.' in my account everytime I logged in. I think I'll send next version of my patch with my email account without '.'. yours, Song Qiang > > --- > > Changes in v5: > > - Correct some spell problems. > > - Change tries-- to --tries to fix the count error. > > - Add MODULE_DEVICE_TABLE(). > > - Add some comments. > > > > Changes in v4: > > - Add datasheet link, default i2c address and TODO list. > > - Make capitalization of defines consistent. > > - Replace i2c_transfer() with i2c_smbus_read_i2c_block_data(). > > - Remove IIO_CHAN_SOFT_TIMESTAMP() since no buffer/trigger > > support. > > - Add information to MAINTAINERS. > > > > Changes in v3: > > - Recover ST's copyright. > > - Clean up indio_dev member in vl53l0x_data struct since it's > > useless now. > > - Replace __le16_to_cpu() with le16_to_cpu(). > > - Remove the iio_device_{claim|release}_direct_mode() since it's > > only needed when we use buffered mode. > > - Clean up some coding style problems. > > > > Changes in v2: > > - Clean up the register table. > > - Sort header files declarations. > > - Replace some bit definations with GENMASK() and BIT(). > > - Clean up some code and comments that's useless for now. > > - Change the order of some the definations of some variables to reversed > > xmas tree order. > > - Using do...while() rather while and check. > > - Replace pr_err() with dev_err(). > > - Remove device id declaration since we recommend to use DT. > > - Remove .owner = THIS_MODULE. > > - Replace probe() with probe_new() hook. > > - Remove IIO_BUFFER and IIO_TRIGGERED_BUFFER dependences. > > - Change the driver module name to vl53l0x-i2c. > > - Align all the parameters if they are in the same function with open > > parentheses. > > - Replace iio_device_register() with devm_iio_device_register > > for better resource management. > > - Remove the vl53l0x_remove() since it's not needed. > > - Remove dev_set_drvdata() since it's already setted above. > > > > .../bindings/iio/proximity/vl53l0x.txt | 12 ++ > > MAINTAINERS | 7 + > > Otherwise, > > Reviewed-by: Rob Herring <robh@kernel.org> > > > drivers/iio/proximity/Kconfig | 11 ++ > > drivers/iio/proximity/Makefile | 2 + > > drivers/iio/proximity/vl53l0x-i2c.c | 180 ++++++++++++++++++ > > 5 files changed, 212 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/iio/proximity/vl53l0x.txt > > create mode 100644 drivers/iio/proximity/vl53l0x-i2c.c
On Sun, 16 Sep 2018 21:36:51 +0800 Song Qiang <songqiang1304521@gmail.com> wrote: > On Sun, Sep 16, 2018 at 12:01:49PM +0100, Jonathan Cameron wrote: > > On Sat, 15 Sep 2018 17:57:52 +0800 > > Song Qiang <songqiang1304521@gmail.com> wrote: > > > > > This driver was originally written by ST in 2016 as a misc input device > > > driver, and hasn't been maintained for a long time. I grabbed some code > > > from it's API and reformed it into an 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 > > > > > > Signed-off-by: Song Qiang <songqiang.1304521@gmail.com> > > Hi Song, > > > > My first comment was going to be don't use wild cards in a part name > > in a driver, but a quick sanity check confirmed that ST were actually > > crazy enough to end a part number with an X. Ah well ;) > > > > Otherwise a few minor things, mostly around naming. There is some > > confusion around endian stuff as well > > > > Looks pretty good for a first go at upstreaming a driver! > > > > Are you planning on adding more features? Seems like a capable little device > > and would be good to have fuller support in the long term if you have time > > to look at it! > > > > Jonathan > > > > Hi Jonathan, > > Thanks for spending time with my patch! > Since I'm now just a student and intrested in embedded linux very much, > there are plenty of free time for me to work on this, and working with > the community is not only interesting but helpful to my knowledge. > People reviewed my patch gave me a lot helpful suggestions, espacially > Himanshu. :) Cool. > > When I was writing this patch, I thought maybe I should go one step > each time, so this driver may seems like a little simple, but I believe > it's just for now. Agreed. It makes complete sense to start simple and build up. I was just being curious on how far you were planning on going ;) > > Actually there is a question, ST released a new version of this device > called VL53L1X in June, which still has no support for linux drivers, > but compitable with VL53L0X. Do you have any suggestions for my > driver's name? The first one came to my mind would be VL53LxX, which is > a little crazy I think. ;) Yes. Wild cards are almost always a bad idea. Just go with the name of the first part you support. If you want example of this see the max1363 ADC driver. That supports lots of seemingly unconnected part numbers so a wild card approach would have caused all sorts of mess. > > ... > > > +// SPDX-License-Identifier: GPL-2.0+ > > > +/* > > > + * Support for ST VL53L0X FlightSense ToF Ranging Sensor on a i2c bus. > > > + * > > > + * Copyright (C) 2016 STMicroelectronics Imaging Division. > > > + * Copyright (C) 2018 Song Qiang <songqiang.1304521@gmail.com> > > > + * > > > + * Datasheet available at > > > + * <https://www.st.com/resource/en/datasheet/vl53l0x.pdf> > > > + * > > > + * Default 7-bit i2c slave address 0x29. > > > + * > > > + * TODO: FIFO buffer, continuous mode, interrupts, range selection, > > > + * sensor ID check. > > > + */ > > > + > > > +#include <linux/module.h> > > > +#include <linux/i2c.h> > > > +#include <linux/delay.h> > > > + > > > +#include <linux/iio/iio.h> > > > + > > > +#define VL53L0X_DRV_NAME "vl53l0x-i2c" > > > > A quick google suggests this only has an i2c interface. Hence I'd argue > > there is no point in having -i2c in the driver name. Lots of other > > i2c only parts don't on the basis it doesn't add anything. In fact > > the only time we tend to do this is if we have a driver that splits > > into a shared core and two or more bus specific drivers. > > > > Actually this device do has a CCI(Camera Control Interface) for > communication and it's original API has two kinds of ways for accessing > this device. Hmm. That one is a bit of a surprise. OK. Fine to do the driver name as *-i2c but don't have it in the iio_dev.name field as it's not really useful to pass on. That usually just contains the part number. Userspace doesn't care about the interface. > > > > + > > > +#define VL_REG_SYSRANGE_START 0x00 > > > + > > > +#define VL_REG_SYSRANGE_MODE_MASK GENMASK(3, 0) > > > +#define VL_REG_SYSRANGE_MODE_SINGLESHOT 0x00 > > > +#define VL_REG_SYSRANGE_MODE_START_STOP BIT(0) > > > +#define VL_REG_SYSRANGE_MODE_BACKTOBACK BIT(1) > > > +#define VL_REG_SYSRANGE_MODE_TIMED BIT(2) > > > +#define VL_REG_SYSRANGE_MODE_HISTOGRAM BIT(3) > > > + > > > +#define VL_REG_SYS_SEQUENCE_CFG BIT(0) > > > +#define VL_REG_SYS_INTERMEASUREMENT_PERIOD BIT(2) > > > +#define VL_REG_SYS_RANGE_CFG 0x09 > > > +#define VL_REG_SYS_INT_GPIO_DISABLED 0x00 > > > +#define VL_REG_SYS_INT_GPIO_LEVEL_LOW BIT(0) > > > +#define VL_REG_SYS_INT_GPIO_LEVEL_HIGH BIT(1) > > > +#define VL_REG_SYS_INT_GPIO_OUT_OF_WINDOW 0x03 > > > +#define VL_REG_SYS_INT_GPIO_NEW_SAMPLE_READY BIT(2) > > > +#define VL_REG_SYS_INT_CFG_GPIO 0x0A > > > +#define VL_REG_SYS_INT_CLEAR 0x0B > > > +#define VL_REG_GPIO_HV_MUX_ACTIVE_HIGH 0x84 > > > + > > > +#define VL_REG_RESULT_INT_STATUS 0x13 > > > +#define VL_REG_RESULT_RANGE_STATUS 0x14 > > > +#define VL_REG_RESULT_RANGE_STATUS_COMPLETE BIT(0) > > > + > > > +/* Check contents of these registers to verify the device. */ > > > +#define VL_REG_IDENTIFICATION_MODEL_ID 0xC0 > > > +#define VL_REG_IDENTIFICATION_REVISION_ID 0xC2 > > > + > > > +struct vl53l0x_data { > > > + struct i2c_client *client; > > > +}; > > > + > > > +static int vl53l0x_read_proximity(struct vl53l0x_data *data, > > > + const struct iio_chan_spec *chan, > > > + int *val) > > > +{ > > > + struct i2c_client *client = data->client; > > > + unsigned int tries = 20; > > > + u8 buffer[12]; > > > + int ret; > > > + > > > + ret = i2c_smbus_write_byte_data(client, > > > + VL_REG_SYSRANGE_START, 1); > > > > Looks like the above would fit on one line. Please do a quick check > > through the driver for other cases of this. > > > > Oops, I'll change that. > > > > + if (ret < 0) > > > + return ret; > > > + > > > + do { > > > + ret = i2c_smbus_read_byte_data(client, > > > + VL_REG_RESULT_RANGE_STATUS); > > > + if (ret < 0) > > > + return ret; > > > + > > > + if (ret & VL_REG_RESULT_RANGE_STATUS_COMPLETE) > > > + break; > > > + > > > + usleep_range(1000, 5000); > > > + } while (--tries); > > > + if (!tries) > > > + return -ETIMEDOUT; > > > + > > > + ret = i2c_smbus_read_i2c_block_data(client, VL_REG_RESULT_RANGE_STATUS, > > > + 12, buffer); > > > + if (ret < 0) > > > + return ret; > > > + else if (ret != 12) > > > + return -EREMOTEIO; > > > + > > > + /* Values should be between 30~1200. */ > > > + *val = le16_to_cpu((buffer[10] << 8) + buffer[11]); > > This worries me as a conversion. The shift and addition is > > unwinding the endianness already. You then do it again with le16_to_cpu > > > > As it's aligned you could have done > > *val = le16_to_cpu(*(le16 *)(&buffer[10])); That's obviously > > a bit ugly though, mainly because we are handling the buffer as > > a u8. Is there a reason to not directly handle it as an le16 array? > > > > I'm having trouble finding the relevant section of the manual to actually > > figure out what is in the first 10 bytes! > > > > > > > > Sorry for this insanity, actually, I was writing this driver without a > full memory layout. I tried to look for one, but then I found the poor ST > support seems like doesn't want to release one at all! Have a look at > this thread on Soren Karlsen's reply: > <https://community.st.com/s/question/0D50X00009XkYTtSAN/request-of-vl53l0x> > All those documents on ST's support websites mentioned only several > registers for connection check. > > I can't say this is a very big deal because at least ST released a full > API source with documentation. I analyzed their API source and also > looked up some usage examples on google to get this device working. > The protocal in the datasheet P19-20 shows that this device has to read > consecutive bytes stream to get all data. I tried to access these > registers one by one but it's not working. > Datasheet: > <https://www.st.com/resource/en/datasheet/vl53l0x.pdf> P19-20 > > Something I know from arduino's example code is that the 11th and 12th > bytes hold distance, the 9th and 10th bytes hold signal countdown > value and 7th and 8th bytes hold ambient countdown value. Hmm. One of 'those' parts. They give almost but not quite enough information to use it in a sane fashion... Oh well, we work with what we have and good there is at least some example code to get things going! > > > > + > > > + return 0; > > > +} > > > + > > > +static const struct iio_chan_spec vl53l0x_channels[] = { > > > + { > > > + .type = IIO_DISTANCE, > > > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), > > > > This is a time of flight sensor? As such I would kind of assume it is possible > > to get to a real world distance? Adding scale and offset to do this can > > of course be a follow up patch, but it would be good to have! > > > > That's right, there was a scale channel, but since this device returns > value in millimeters I thought there isn't a need for that channel, so > I just return raw value. If it's already in mm then you should use _PROCESSED not _RAW to indicate that to userspace. Right now userspace would think that there was no known scaling. > Usually in our production, we do some linear calibration for it's return > values, but I think this may should be left with userspace to do. That's normal. We give as much information as possible, but if you want any really precise values off a sensor then it's up to you to calibrate it offline. > > > > + }, > > > +}; > > > + ... Jonathan
On Mon, Sep 17, 2018 at 09:25:21AM +0100, Jonathan Cameron wrote: > On Sun, 16 Sep 2018 21:36:51 +0800 > Song Qiang <songqiang1304521@gmail.com> wrote: > > > On Sun, Sep 16, 2018 at 12:01:49PM +0100, Jonathan Cameron wrote: > > > On Sat, 15 Sep 2018 17:57:52 +0800 > > > Song Qiang <songqiang1304521@gmail.com> wrote: > > > > > > > This driver was originally written by ST in 2016 as a misc input device > > > > driver, and hasn't been maintained for a long time. I grabbed some code > > > > from it's API and reformed it into an 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 > > > > > > > > Signed-off-by: Song Qiang <songqiang.1304521@gmail.com> > > > Hi Song, > > > > > > My first comment was going to be don't use wild cards in a part name > > > in a driver, but a quick sanity check confirmed that ST were actually > > > crazy enough to end a part number with an X. Ah well ;) > > > > > > Otherwise a few minor things, mostly around naming. There is some > > > confusion around endian stuff as well > > > > > > Looks pretty good for a first go at upstreaming a driver! > > > > > > Are you planning on adding more features? Seems like a capable little device > > > and would be good to have fuller support in the long term if you have time > > > to look at it! > > > > > > Jonathan > > > > > > > Hi Jonathan, > > > > Thanks for spending time with my patch! > > Since I'm now just a student and intrested in embedded linux very much, > > there are plenty of free time for me to work on this, and working with > > the community is not only interesting but helpful to my knowledge. > > People reviewed my patch gave me a lot helpful suggestions, espacially > > Himanshu. :) > Cool. > > > > > When I was writing this patch, I thought maybe I should go one step > > each time, so this driver may seems like a little simple, but I believe > > it's just for now. > Agreed. It makes complete sense to start simple and build up. I was > just being curious on how far you were planning on going ;) > I was just working on the interrupt. I think I'll submit the second patch to make interrupt working tommorow. > > > > Actually there is a question, ST released a new version of this device > > called VL53L1X in June, which still has no support for linux drivers, > > but compitable with VL53L0X. Do you have any suggestions for my > > driver's name? The first one came to my mind would be VL53LxX, which is > > a little crazy I think. ;) > Yes. Wild cards are almost always a bad idea. Just go with the name > of the first part you support. > > If you want example of this see the max1363 ADC driver. That supports > lots of seemingly unconnected part numbers so a wild card approach would > have caused all sorts of mess. > I see, that's a good idea. > > > > > ... > > > > > +// SPDX-License-Identifier: GPL-2.0+ > > > > +/* > > > > + * Support for ST VL53L0X FlightSense ToF Ranging Sensor on a i2c bus. > > > > + * > > > > + * Copyright (C) 2016 STMicroelectronics Imaging Division. > > > > + * Copyright (C) 2018 Song Qiang <songqiang.1304521@gmail.com> > > > > + * > > > > + * Datasheet available at > > > > + * <https://www.st.com/resource/en/datasheet/vl53l0x.pdf> > > > > + * > > > > + * Default 7-bit i2c slave address 0x29. > > > > + * > > > > + * TODO: FIFO buffer, continuous mode, interrupts, range selection, > > > > + * sensor ID check. > > > > + */ > > > > + > > > > +#include <linux/module.h> > > > > +#include <linux/i2c.h> > > > > +#include <linux/delay.h> > > > > + > > > > +#include <linux/iio/iio.h> > > > > + > > > > +#define VL53L0X_DRV_NAME "vl53l0x-i2c" > > > > > > A quick google suggests this only has an i2c interface. Hence I'd argue > > > there is no point in having -i2c in the driver name. Lots of other > > > i2c only parts don't on the basis it doesn't add anything. In fact > > > the only time we tend to do this is if we have a driver that splits > > > into a shared core and two or more bus specific drivers. > > > > > > > Actually this device do has a CCI(Camera Control Interface) for > > communication and it's original API has two kinds of ways for accessing > > this device. > Hmm. That one is a bit of a surprise. > > OK. Fine to do the driver name as *-i2c but don't have it in the > iio_dev.name field as it's not really useful to pass on. That > usually just contains the part number. Userspace doesn't care about the > interface. > I'll remove that. > > > > > > + > > > > +#define VL_REG_SYSRANGE_START 0x00 > > > > + > > > > +#define VL_REG_SYSRANGE_MODE_MASK GENMASK(3, 0) > > > > +#define VL_REG_SYSRANGE_MODE_SINGLESHOT 0x00 > > > > +#define VL_REG_SYSRANGE_MODE_START_STOP BIT(0) > > > > +#define VL_REG_SYSRANGE_MODE_BACKTOBACK BIT(1) > > > > +#define VL_REG_SYSRANGE_MODE_TIMED BIT(2) > > > > +#define VL_REG_SYSRANGE_MODE_HISTOGRAM BIT(3) > > > > + > > > > +#define VL_REG_SYS_SEQUENCE_CFG BIT(0) > > > > +#define VL_REG_SYS_INTERMEASUREMENT_PERIOD BIT(2) > > > > +#define VL_REG_SYS_RANGE_CFG 0x09 > > > > +#define VL_REG_SYS_INT_GPIO_DISABLED 0x00 > > > > +#define VL_REG_SYS_INT_GPIO_LEVEL_LOW BIT(0) > > > > +#define VL_REG_SYS_INT_GPIO_LEVEL_HIGH BIT(1) > > > > +#define VL_REG_SYS_INT_GPIO_OUT_OF_WINDOW 0x03 > > > > +#define VL_REG_SYS_INT_GPIO_NEW_SAMPLE_READY BIT(2) > > > > +#define VL_REG_SYS_INT_CFG_GPIO 0x0A > > > > +#define VL_REG_SYS_INT_CLEAR 0x0B > > > > +#define VL_REG_GPIO_HV_MUX_ACTIVE_HIGH 0x84 > > > > + > > > > +#define VL_REG_RESULT_INT_STATUS 0x13 > > > > +#define VL_REG_RESULT_RANGE_STATUS 0x14 > > > > +#define VL_REG_RESULT_RANGE_STATUS_COMPLETE BIT(0) > > > > + > > > > +/* Check contents of these registers to verify the device. */ > > > > +#define VL_REG_IDENTIFICATION_MODEL_ID 0xC0 > > > > +#define VL_REG_IDENTIFICATION_REVISION_ID 0xC2 > > > > + > > > > +struct vl53l0x_data { > > > > + struct i2c_client *client; > > > > +}; > > > > + > > > > +static int vl53l0x_read_proximity(struct vl53l0x_data *data, > > > > + const struct iio_chan_spec *chan, > > > > + int *val) > > > > +{ > > > > + struct i2c_client *client = data->client; > > > > + unsigned int tries = 20; > > > > + u8 buffer[12]; > > > > + int ret; > > > > + > > > > + ret = i2c_smbus_write_byte_data(client, > > > > + VL_REG_SYSRANGE_START, 1); > > > > > > Looks like the above would fit on one line. Please do a quick check > > > through the driver for other cases of this. > > > > > > > Oops, I'll change that. > > > > > > + if (ret < 0) > > > > + return ret; > > > > + > > > > + do { > > > > + ret = i2c_smbus_read_byte_data(client, > > > > + VL_REG_RESULT_RANGE_STATUS); > > > > + if (ret < 0) > > > > + return ret; > > > > + > > > > + if (ret & VL_REG_RESULT_RANGE_STATUS_COMPLETE) > > > > + break; > > > > + > > > > + usleep_range(1000, 5000); > > > > + } while (--tries); > > > > + if (!tries) > > > > + return -ETIMEDOUT; > > > > + > > > > + ret = i2c_smbus_read_i2c_block_data(client, VL_REG_RESULT_RANGE_STATUS, > > > > + 12, buffer); > > > > + if (ret < 0) > > > > + return ret; > > > > + else if (ret != 12) > > > > + return -EREMOTEIO; > > > > + > > > > + /* Values should be between 30~1200. */ > > > > + *val = le16_to_cpu((buffer[10] << 8) + buffer[11]); > > > This worries me as a conversion. The shift and addition is > > > unwinding the endianness already. You then do it again with le16_to_cpu > > > > > > As it's aligned you could have done > > > *val = le16_to_cpu(*(le16 *)(&buffer[10])); That's obviously > > > a bit ugly though, mainly because we are handling the buffer as > > > a u8. Is there a reason to not directly handle it as an le16 array? > > > > > > I'm having trouble finding the relevant section of the manual to actually > > > figure out what is in the first 10 bytes! > > > > > > > > > > > > > Sorry for this insanity, actually, I was writing this driver without a > > full memory layout. I tried to look for one, but then I found the poor ST > > support seems like doesn't want to release one at all! Have a look at > > this thread on Soren Karlsen's reply: > > <https://community.st.com/s/question/0D50X00009XkYTtSAN/request-of-vl53l0x> > > All those documents on ST's support websites mentioned only several > > registers for connection check. > > > > I can't say this is a very big deal because at least ST released a full > > API source with documentation. I analyzed their API source and also > > looked up some usage examples on google to get this device working. > > The protocal in the datasheet P19-20 shows that this device has to read > > consecutive bytes stream to get all data. I tried to access these > > registers one by one but it's not working. > > Datasheet: > > <https://www.st.com/resource/en/datasheet/vl53l0x.pdf> P19-20 > > > > Something I know from arduino's example code is that the 11th and 12th > > bytes hold distance, the 9th and 10th bytes hold signal countdown > > value and 7th and 8th bytes hold ambient countdown value. > > Hmm. One of 'those' parts. They give almost but not quite enough information > to use it in a sane fashion... Oh well, we work with what we have and good > there is at least some example code to get things going! > > > > > > > + > > > > + return 0; > > > > +} > > > > + > > > > +static const struct iio_chan_spec vl53l0x_channels[] = { > > > > + { > > > > + .type = IIO_DISTANCE, > > > > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), > > > > > > This is a time of flight sensor? As such I would kind of assume it is possible > > > to get to a real world distance? Adding scale and offset to do this can > > > of course be a follow up patch, but it would be good to have! > > > > > > > That's right, there was a scale channel, but since this device returns > > value in millimeters I thought there isn't a need for that channel, so > > I just return raw value. > > If it's already in mm then you should use _PROCESSED not _RAW > to indicate that to userspace. Right now userspace would think that there > was no known scaling. > That's something I didn't know, seems like more documents should to read. > > Usually in our production, we do some linear calibration for it's return > > values, but I think this may should be left with userspace to do. > > That's normal. We give as much information as possible, but if you want any > really precise values off a sensor then it's up to you to calibrate it offline. > > > > > > > + }, > > > > +}; > > > > + > ... > > Jonathan > > yours, Song Qiang
... > > > > .../bindings/iio/proximity/vl53l0x.txt | 12 ++ > > MAINTAINERS | 7 + > > Otherwise, > > Reviewed-by: Rob Herring <robh@kernel.org> Hi Song, Please make sure to pick up the various Acks, Reviewed-bys etc for later versions. I've added this to the version I applied. Thanks, Jonathan > > > drivers/iio/proximity/Kconfig | 11 ++ > > drivers/iio/proximity/Makefile | 2 + > > drivers/iio/proximity/vl53l0x-i2c.c | 180 ++++++++++++++++++ > > 5 files changed, 212 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/iio/proximity/vl53l0x.txt > > create mode 100644 drivers/iio/proximity/vl53l0x-i2c.c
diff --git a/Documentation/devicetree/bindings/iio/proximity/vl53l0x.txt b/Documentation/devicetree/bindings/iio/proximity/vl53l0x.txt new file mode 100644 index 000000000000..ab9a9539fec4 --- /dev/null +++ b/Documentation/devicetree/bindings/iio/proximity/vl53l0x.txt @@ -0,0 +1,12 @@ +ST VL53L0X ToF ranging sensor + +Required properties: + - compatible: must be "st,vl53l0x-i2c" + - reg: i2c address where to find the device + +Example: + +vl53l0x@29 { + compatible = "st,vl53l0x-i2c"; + reg = <0x29>; +}; diff --git a/MAINTAINERS b/MAINTAINERS index 967ce8cdd1cc..a35d80e63506 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -13510,6 +13510,13 @@ L: linux-i2c@vger.kernel.org S: Maintained F: drivers/i2c/busses/i2c-stm32* +ST VL53L0X ToF RANGER(I2C) IIO DRIVER +M: Song Qiang <songqiang.1304521@gmail.com> +L: linux-iio@vger.kernel.org +S: Maintained +F: drivers/iio/proximity/vl53l0x-i2c.c +F: Documentation/devicetree/bindings/iio/proximity/vl53l0x.txt + STABLE BRANCH M: Greg Kroah-Hartman <gregkh@linuxfoundation.org> L: stable@vger.kernel.org diff --git a/drivers/iio/proximity/Kconfig b/drivers/iio/proximity/Kconfig index f726f9427602..5f421cbd37f3 100644 --- a/drivers/iio/proximity/Kconfig +++ b/drivers/iio/proximity/Kconfig @@ -79,4 +79,15 @@ config SRF08 To compile this driver as a module, choose M here: the module will be called srf08. +config VL53L0X_I2C + tristate "STMicroelectronics VL53L0X ToF ranger sensor (I2C)" + depends on I2C + help + Say Y here to build a driver for STMicroelectronics VL53L0X + ToF ranger sensors with i2c interface. + This driver can be used to measure the distance of objects. + + To compile this driver as a module, choose M here: the + module will be called vl53l0x-i2c. + endmenu diff --git a/drivers/iio/proximity/Makefile b/drivers/iio/proximity/Makefile index 4f4ed45e87ef..dedfb5bf3475 100644 --- a/drivers/iio/proximity/Makefile +++ b/drivers/iio/proximity/Makefile @@ -10,3 +10,5 @@ obj-$(CONFIG_RFD77402) += rfd77402.o obj-$(CONFIG_SRF04) += srf04.o obj-$(CONFIG_SRF08) += srf08.o obj-$(CONFIG_SX9500) += sx9500.o +obj-$(CONFIG_VL53L0X_I2C) += vl53l0x-i2c.o + diff --git a/drivers/iio/proximity/vl53l0x-i2c.c b/drivers/iio/proximity/vl53l0x-i2c.c new file mode 100644 index 000000000000..4837cc2fff19 --- /dev/null +++ b/drivers/iio/proximity/vl53l0x-i2c.c @@ -0,0 +1,180 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Support for ST VL53L0X FlightSense ToF Ranging Sensor on a i2c bus. + * + * Copyright (C) 2016 STMicroelectronics Imaging Division. + * Copyright (C) 2018 Song Qiang <songqiang.1304521@gmail.com> + * + * Datasheet available at + * <https://www.st.com/resource/en/datasheet/vl53l0x.pdf> + * + * Default 7-bit i2c slave address 0x29. + * + * TODO: FIFO buffer, continuous mode, interrupts, range selection, + * sensor ID check. + */ + +#include <linux/module.h> +#include <linux/i2c.h> +#include <linux/delay.h> + +#include <linux/iio/iio.h> + +#define VL53L0X_DRV_NAME "vl53l0x-i2c" + +#define VL_REG_SYSRANGE_START 0x00 + +#define VL_REG_SYSRANGE_MODE_MASK GENMASK(3, 0) +#define VL_REG_SYSRANGE_MODE_SINGLESHOT 0x00 +#define VL_REG_SYSRANGE_MODE_START_STOP BIT(0) +#define VL_REG_SYSRANGE_MODE_BACKTOBACK BIT(1) +#define VL_REG_SYSRANGE_MODE_TIMED BIT(2) +#define VL_REG_SYSRANGE_MODE_HISTOGRAM BIT(3) + +#define VL_REG_SYS_SEQUENCE_CFG BIT(0) +#define VL_REG_SYS_INTERMEASUREMENT_PERIOD BIT(2) +#define VL_REG_SYS_RANGE_CFG 0x09 +#define VL_REG_SYS_INT_GPIO_DISABLED 0x00 +#define VL_REG_SYS_INT_GPIO_LEVEL_LOW BIT(0) +#define VL_REG_SYS_INT_GPIO_LEVEL_HIGH BIT(1) +#define VL_REG_SYS_INT_GPIO_OUT_OF_WINDOW 0x03 +#define VL_REG_SYS_INT_GPIO_NEW_SAMPLE_READY BIT(2) +#define VL_REG_SYS_INT_CFG_GPIO 0x0A +#define VL_REG_SYS_INT_CLEAR 0x0B +#define VL_REG_GPIO_HV_MUX_ACTIVE_HIGH 0x84 + +#define VL_REG_RESULT_INT_STATUS 0x13 +#define VL_REG_RESULT_RANGE_STATUS 0x14 +#define VL_REG_RESULT_RANGE_STATUS_COMPLETE BIT(0) + +/* Check contents of these registers to verify the device. */ +#define VL_REG_IDENTIFICATION_MODEL_ID 0xC0 +#define VL_REG_IDENTIFICATION_REVISION_ID 0xC2 + +struct vl53l0x_data { + struct i2c_client *client; +}; + +static int vl53l0x_read_proximity(struct vl53l0x_data *data, + const struct iio_chan_spec *chan, + int *val) +{ + struct i2c_client *client = data->client; + unsigned int tries = 20; + u8 buffer[12]; + int ret; + + ret = i2c_smbus_write_byte_data(client, + VL_REG_SYSRANGE_START, 1); + if (ret < 0) + return ret; + + do { + ret = i2c_smbus_read_byte_data(client, + VL_REG_RESULT_RANGE_STATUS); + if (ret < 0) + return ret; + + if (ret & VL_REG_RESULT_RANGE_STATUS_COMPLETE) + break; + + usleep_range(1000, 5000); + } while (--tries); + if (!tries) + return -ETIMEDOUT; + + ret = i2c_smbus_read_i2c_block_data(client, VL_REG_RESULT_RANGE_STATUS, + 12, buffer); + if (ret < 0) + return ret; + else if (ret != 12) + return -EREMOTEIO; + + /* Values should be between 30~1200. */ + *val = le16_to_cpu((buffer[10] << 8) + buffer[11]); + + return 0; +} + +static const struct iio_chan_spec vl53l0x_channels[] = { + { + .type = IIO_DISTANCE, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + }, +}; + +static int vl53l0x_read_raw(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + int *val, int *val2, long mask) +{ + struct vl53l0x_data *data = iio_priv(indio_dev); + int ret; + + if (chan->type != IIO_DISTANCE) { + dev_err(&data->client->dev, "iio type error"); + return -EINVAL; + } + + switch (mask) { + case IIO_CHAN_INFO_RAW: + ret = vl53l0x_read_proximity(data, chan, val); + if (ret < 0) + dev_err(&data->client->dev, + "raw value read error with %d", ret); + + return IIO_VAL_INT; + default: + dev_err(&data->client->dev, "IIO_CHAN_* not recognized."); + return -EINVAL; + } +} + +static const struct iio_info vl53l0x_info = { + .read_raw = vl53l0x_read_raw, +}; + +static int vl53l0x_probe(struct i2c_client *client) +{ + 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); + + if (!i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_READ_I2C_BLOCK | I2C_FUNC_SMBUS_BYTE_DATA)) + 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; + + return devm_iio_device_register(&client->dev, indio_dev); +} + +static const struct of_device_id st_vl53l0x_dt_match[] = { + { .compatible = "st,vl53l0x-i2c", }, + { } +}; +MODULE_DEVICE_TABLE(of, st_vl53l0x_dt_match); + +static struct i2c_driver vl53l0x_driver = { + .driver = { + .name = VL53L0X_DRV_NAME, + .of_match_table = st_vl53l0x_dt_match, + }, + .probe_new = vl53l0x_probe, +}; +module_i2c_driver(vl53l0x_driver); + +MODULE_AUTHOR("Song Qiang <songqiang.1304521@gmail.com>"); +MODULE_DESCRIPTION("ST vl53l0x ToF ranging sensor driver"); +MODULE_LICENSE("GPL v2");
This driver was originally written by ST in 2016 as a misc input device driver, and hasn't been maintained for a long time. I grabbed some code from it's API and reformed it into an 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 Signed-off-by: Song Qiang <songqiang.1304521@gmail.com> --- Changes in v5: - Correct some spell problems. - Change tries-- to --tries to fix the count error. - Add MODULE_DEVICE_TABLE(). - Add some comments. Changes in v4: - Add datasheet link, default i2c address and TODO list. - Make capitalization of defines consistent. - Replace i2c_transfer() with i2c_smbus_read_i2c_block_data(). - Remove IIO_CHAN_SOFT_TIMESTAMP() since no buffer/trigger support. - Add information to MAINTAINERS. Changes in v3: - Recover ST's copyright. - Clean up indio_dev member in vl53l0x_data struct since it's useless now. - Replace __le16_to_cpu() with le16_to_cpu(). - Remove the iio_device_{claim|release}_direct_mode() since it's only needed when we use buffered mode. - Clean up some coding style problems. Changes in v2: - Clean up the register table. - Sort header files declarations. - Replace some bit definations with GENMASK() and BIT(). - Clean up some code and comments that's useless for now. - Change the order of some the definations of some variables to reversed xmas tree order. - Using do...while() rather while and check. - Replace pr_err() with dev_err(). - Remove device id declaration since we recommend to use DT. - Remove .owner = THIS_MODULE. - Replace probe() with probe_new() hook. - Remove IIO_BUFFER and IIO_TRIGGERED_BUFFER dependences. - Change the driver module name to vl53l0x-i2c. - Align all the parameters if they are in the same function with open parentheses. - Replace iio_device_register() with devm_iio_device_register for better resource management. - Remove the vl53l0x_remove() since it's not needed. - Remove dev_set_drvdata() since it's already setted above. .../bindings/iio/proximity/vl53l0x.txt | 12 ++ MAINTAINERS | 7 + drivers/iio/proximity/Kconfig | 11 ++ drivers/iio/proximity/Makefile | 2 + drivers/iio/proximity/vl53l0x-i2c.c | 180 ++++++++++++++++++ 5 files changed, 212 insertions(+) create mode 100644 Documentation/devicetree/bindings/iio/proximity/vl53l0x.txt create mode 100644 drivers/iio/proximity/vl53l0x-i2c.c