Re: [PATCH v2 4/4] iio: vcnl4000: add support for VCNL4200

[Jonathan Cameron <jic23@kernel.org>]

On Mon, 23 Jul 2018 19:32:31 +0200
Tomas Novotny <tomas@novotny.cz> wrote:

> Hi Jonathan,
> 
> On Sat, 21 Jul 2018 18:20:21 +0100
> Jonathan Cameron <jic23@kernel.org> wrote:
> 
> > On Tue, 17 Jul 2018 18:46:55 +0200
> > Tomas Novotny <tomas@novotny.cz> wrote:
> >   
> > > VCNL4200 is an integrated long distance (up to 1500mm) proximity and
> > > ambient light sensor.
> > > 
> > > The support is very basic. There is no configuration of proximity and
> > > ambient light sensing yet. Only the reading of both measured values is
> > > done.
> > > 
> > > The reading of ambient light and proximity values is blocking. If you
> > > request a new value too early, the driver waits for new value to be
> > > ready.
> > > 
> > > Signed-off-by: Tomas Novotny <tomas@novotny.cz>    
> > 
> > A comment inline, but nothing much needs changing.
> > 
> > Jonathan
> >   
> > > ---
> > >  drivers/iio/light/Kconfig    |   5 +-
> > >  drivers/iio/light/vcnl4000.c | 114 ++++++++++++++++++++++++++++++++++++++++---
> > >  2 files changed, 109 insertions(+), 10 deletions(-)
> > > 
> > > diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
> > > index 074e50657366..c0344a961f54 100644
> > > --- a/drivers/iio/light/Kconfig
> > > +++ b/drivers/iio/light/Kconfig
> > > @@ -430,11 +430,12 @@ config US5182D
> > >  	 will be called us5182d.
> > >  
> > >  config VCNL4000
> > > -	tristate "VCNL4000/4010/4020 combined ALS and proximity sensor"
> > > +	tristate "VCNL4000/4010/4020/4200 combined ALS and proximity sensor"
> > >  	depends on I2C
> > >  	help
> > >  	 Say Y here if you want to build a driver for the Vishay VCNL4000,
> > > -	 VCNL4010, VCNL4020 combined ambient light and proximity sensor.
> > > +	 VCNL4010, VCNL4020, VCNL4200 combined ambient light and proximity
> > > +	 sensor.
> > >  
> > >  	 To compile this driver as a module, choose M here: the
> > >  	 module will be called vcnl4000.
> > > diff --git a/drivers/iio/light/vcnl4000.c b/drivers/iio/light/vcnl4000.c
> > > index 642a366c1479..5de0d500c310 100644
> > > --- a/drivers/iio/light/vcnl4000.c
> > > +++ b/drivers/iio/light/vcnl4000.c
> > > @@ -1,5 +1,5 @@
> > >  /*
> > > - * vcnl4000.c - Support for Vishay VCNL4000/4010/4020 combined ambient
> > > + * vcnl4000.c - Support for Vishay VCNL4000/4010/4020/4200 combined ambient
> > >   * light and proximity sensor
> > >   *
> > >   * Copyright 2012 Peter Meerwald <pmeerw@pmeerw.net>
> > > @@ -8,13 +8,15 @@
> > >   * the GNU General Public License.  See the file COPYING in the main
> > >   * directory of this archive for more details.
> > >   *
> > > - * IIO driver for VCNL4000 (7-bit I2C slave address 0x13)
> > > + * IIO driver for:
> > > + *   VCNL4000/10/20 (7-bit I2C slave address 0x13)
> > > + *   VCNL4200 (7-bit I2C slave address 0x51)
> > >   *
> > >   * TODO:
> > >   *   allow to adjust IR current
> > >   *   proximity threshold and event handling
> > >   *   periodic ALS/proximity measurement (VCNL4010/20)
> > > - *   interrupts (VCNL4010/20)
> > > + *   interrupts (VCNL4010/20, VCNL4200)
> > >   */
> > >  
> > >  #include <linux/module.h>
> > > @@ -28,6 +30,7 @@
> > >  #define VCNL4000_DRV_NAME "vcnl4000"
> > >  #define VCNL4000_PROD_ID	0x01
> > >  #define VCNL4010_PROD_ID	0x02 /* for VCNL4020, VCNL4010 */
> > > +#define VCNL4200_PROD_ID	0x58
> > >  
> > >  #define VCNL4000_COMMAND	0x80 /* Command register */
> > >  #define VCNL4000_PROD_REV	0x81 /* Product ID and Revision ID */
> > > @@ -40,6 +43,12 @@
> > >  #define VCNL4000_PS_MEAS_FREQ	0x89 /* Proximity test signal frequency */
> > >  #define VCNL4000_PS_MOD_ADJ	0x8a /* Proximity modulator timing adjustment */
> > >  
> > > +#define VCNL4200_AL_CONF	0x00 /* Ambient light configuration */
> > > +#define VCNL4200_PS_CONF1	0x03 /* Proximity configuration */
> > > +#define VCNL4200_PS_DATA	0x08 /* Proximity data */
> > > +#define VCNL4200_AL_DATA	0x09 /* Ambient light data */
> > > +#define VCNL4200_DEV_ID		0x0e /* Device ID, slave address and version */
> > > +
> > >  /* Bit masks for COMMAND register */
> > >  #define VCNL4000_AL_RDY		BIT(6) /* ALS data ready? */
> > >  #define VCNL4000_PS_RDY		BIT(5) /* proximity data ready? */
> > > @@ -49,6 +58,14 @@
> > >  enum vcnl4000_device_ids {
> > >  	VCNL4000,
> > >  	VCNL4010,
> > > +	VCNL4200,
> > > +};
> > > +
> > > +struct vcnl4200_channel {
> > > +	u8 reg;
> > > +	ktime_t last_measurement;
> > > +	ktime_t sampling_rate;
> > > +	struct mutex lock;
> > >  };
> > >  
> > >  struct vcnl4000_data {
> > > @@ -57,7 +74,9 @@ struct vcnl4000_data {
> > >  	int rev;
> > >  	int al_scale;
> > >  	const struct vcnl4000_chip_spec *chip_spec;
> > > -	struct mutex lock;
> > > +	struct mutex vcnl4000_lock;
> > > +	struct vcnl4200_channel vcnl4200_al;
> > > +	struct vcnl4200_channel vcnl4200_ps;
> > >  };
> > >  
> > >  struct vcnl4000_chip_spec {
> > > @@ -70,6 +89,7 @@ struct vcnl4000_chip_spec {
> > >  static const struct i2c_device_id vcnl4000_id[] = {
> > >  	{ "vcnl4000", VCNL4000 },
> > >  	{ "vcnl4010", VCNL4010 },
> > > +	{ "vcnl4200", VCNL4200 },
> > >  	{ }
> > >  };
> > >  MODULE_DEVICE_TABLE(i2c, vcnl4000_id);
> > > @@ -100,6 +120,42 @@ static int vcnl4000_init(struct vcnl4000_data *data)
> > >  
> > >  	data->rev = ret & 0xf;
> > >  	data->al_scale = 250000;
> > > +	mutex_init(&data->vcnl4000_lock);
> > > +
> > > +	return 0;
> > > +};
> > > +
> > > +static int vcnl4200_init(struct vcnl4000_data *data)
> > > +{
> > > +	int ret;
> > > +
> > > +	ret = i2c_smbus_read_word_data(data->client, VCNL4200_DEV_ID);
> > > +	if (ret < 0)
> > > +		return ret;
> > > +
> > > +	if ((ret & 0xff) != VCNL4200_PROD_ID)
> > > +		return -ENODEV;
> > > +
> > > +	data->rev = (ret >> 8) & 0xf;
> > > +
> > > +	/* Set defaults and enable both channels */
> > > +	ret = i2c_smbus_write_byte_data(data->client, VCNL4200_AL_CONF, 0x00);
> > > +	if (ret < 0)
> > > +		return ret;
> > > +	ret = i2c_smbus_write_byte_data(data->client, VCNL4200_PS_CONF1, 0x00);
> > > +	if (ret < 0)
> > > +		return ret;
> > > +
> > > +	data->al_scale = 24000;
> > > +	data->vcnl4200_al.reg = VCNL4200_AL_DATA;
> > > +	data->vcnl4200_ps.reg = VCNL4200_PS_DATA;
> > > +	/* Integration time is 50ms, but the experiments show 54ms in total. */
> > > +	data->vcnl4200_al.sampling_rate = ktime_set(0, 54000 * 1000);
> > > +	data->vcnl4200_ps.sampling_rate = ktime_set(0, 4200 * 1000);    
> > 
> > I'm not particularly keen on the mixing of constant and non constant
> > stuff in these, but I guess there isn't enough constant stuff to bother
> > factoring that out.  
> 
> If you wouldn't mind, I would leave it as it is. The sampling rate isn't
> fixed - this value is just a default value after reset. There are some
> settings which influence it, so it might be computed when the driver will be
> extended.

Fair enough. Fine as it is.

Jonathan

> 
> Thanks,
> 
> Tomas
> 
> > > +	data->vcnl4200_al.last_measurement = ktime_set(0, 0);
> > > +	data->vcnl4200_ps.last_measurement = ktime_set(0, 0);
> > > +	mutex_init(&data->vcnl4200_al.lock);
> > > +	mutex_init(&data->vcnl4200_ps.lock);
> > >  
> > >  	return 0;
> > >  };
> > > @@ -111,7 +167,7 @@ static int vcnl4000_measure(struct vcnl4000_data *data, u8 req_mask,
> > >  	__be16 buf;
> > >  	int ret;
> > >  
> > > -	mutex_lock(&data->lock);
> > > +	mutex_lock(&data->vcnl4000_lock);
> > >  
> > >  	ret = i2c_smbus_write_byte_data(data->client, VCNL4000_COMMAND,
> > >  					req_mask);
> > > @@ -140,16 +196,43 @@ static int vcnl4000_measure(struct vcnl4000_data *data, u8 req_mask,
> > >  	if (ret < 0)
> > >  		goto fail;
> > >  
> > > -	mutex_unlock(&data->lock);
> > > +	mutex_unlock(&data->vcnl4000_lock);
> > >  	*val = be16_to_cpu(buf);
> > >  
> > >  	return 0;
> > >  
> > >  fail:
> > > -	mutex_unlock(&data->lock);
> > > +	mutex_unlock(&data->vcnl4000_lock);
> > >  	return ret;
> > >  }
> > >  
> > > +static int vcnl4200_measure(struct vcnl4000_data *data,
> > > +		struct vcnl4200_channel *chan, int *val)
> > > +{
> > > +	int ret;
> > > +	s64 delta;
> > > +	ktime_t next_measurement;
> > > +
> > > +	mutex_lock(&chan->lock);
> > > +
> > > +	next_measurement = ktime_add(chan->last_measurement,
> > > +			chan->sampling_rate);
> > > +	delta = ktime_us_delta(next_measurement, ktime_get());
> > > +	if (delta > 0)
> > > +		usleep_range(delta, delta + 500);
> > > +	chan->last_measurement = ktime_get();
> > > +
> > > +	mutex_unlock(&chan->lock);
> > > +
> > > +	ret = i2c_smbus_read_word_data(data->client, chan->reg);
> > > +	if (ret < 0)
> > > +		return ret;
> > > +
> > > +	*val = ret;
> > > +
> > > +	return 0;
> > > +}
> > > +
> > >  static int vcnl4000_measure_light(struct vcnl4000_data *data, int *val)
> > >  {
> > >  	return vcnl4000_measure(data,
> > > @@ -157,6 +240,11 @@ static int vcnl4000_measure_light(struct vcnl4000_data *data, int *val)
> > >  			VCNL4000_AL_RESULT_HI, val);
> > >  }
> > >  
> > > +static int vcnl4200_measure_light(struct vcnl4000_data *data, int *val)
> > > +{
> > > +	return vcnl4200_measure(data, &data->vcnl4200_al, val);
> > > +}
> > > +
> > >  static int vcnl4000_measure_proximity(struct vcnl4000_data *data, int *val)
> > >  {
> > >  	return vcnl4000_measure(data,
> > > @@ -164,6 +252,11 @@ static int vcnl4000_measure_proximity(struct vcnl4000_data *data, int *val)
> > >  			VCNL4000_PS_RESULT_HI, val);
> > >  }
> > >  
> > > +static int vcnl4200_measure_proximity(struct vcnl4000_data *data, int *val)
> > > +{
> > > +	return vcnl4200_measure(data, &data->vcnl4200_ps, val);
> > > +}
> > > +
> > >  static const struct vcnl4000_chip_spec vcnl4000_chip_spec_cfg[] = {
> > >  	[VCNL4000] = {
> > >  		.prod = "VCNL4000",
> > > @@ -177,6 +270,12 @@ static const struct vcnl4000_chip_spec vcnl4000_chip_spec_cfg[] = {
> > >  		.measure_light = vcnl4000_measure_light,
> > >  		.measure_proximity = vcnl4000_measure_proximity,
> > >  	},
> > > +	[VCNL4200] = {
> > > +		.prod = "VCNL4200",
> > > +		.init = vcnl4200_init,
> > > +		.measure_light = vcnl4200_measure_light,
> > > +		.measure_proximity = vcnl4200_measure_proximity,
> > > +	},
> > >  };
> > >  
> > >  static const struct iio_chan_spec vcnl4000_channels[] = {
> > > @@ -245,7 +344,6 @@ static int vcnl4000_probe(struct i2c_client *client,
> > >  	data->client = client;
> > >  	data->id = id->driver_data;
> > >  	data->chip_spec = &vcnl4000_chip_spec_cfg[data->id];
> > > -	mutex_init(&data->lock);
> > >  
> > >  	ret = data->chip_spec->init(data);
> > >  	if (ret < 0)    
> > 
> > --
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