Re: [PATCH v7 1/1] iio: jsa1212: Add JSA1212 proximity/ALS sensor

[sathyanarayanan kuppuswamy <sathyanarayanan.kuppuswamy@linux.intel.com>]

Thanks for your comments Srinivas.

Jonathan,

If you agree with Srinivas comment. I think we don't need to remove the 
suspend call backs from the driver.


On 10/11/2014 07:57 AM, Srinivas Pandruvada wrote:
> On Thu, 2014-10-09 at 20:26 +0100, Jonathan Cameron wrote:
>> On 07/10/14 21:09, sathyanarayanan kuppuswamy wrote:
>>> Hi Jonathan,
>>>
>>> On 09/29/2014 03:00 PM, sathyanarayanan kuppuswamy wrote:
>>>> Hi Jonathan,
>>>>
>>>> On 09/21/2014 05:52 AM, Jonathan Cameron wrote:
>>>>> On 17/09/14 21:59, sathyanarayanan kuppuswamy wrote:
>>>>>> Hi Hartmut,
>>>>>>
>>>>>> On 09/17/2014 01:48 PM, Hartmut Knaack wrote:
>>>>>>> Kuppuswamy Sathyanarayanan schrieb, Am 16.09.2014 05:54:
>>>>>>>> This patch adds a new driver for solteam opto JSA1212 proximity and
>>>>>>>> ambient light sensor.
>>>>>>>>
>>>>>>>> Basic details of the chip can be found here.
>>>>>>>>
>>>>>>>> http://www.solteamopto.com.tw/detail.php?ms=3&po_unit=2&pt_unit=29&p_unit=120
>>>>>>> Hi,
>>>>>>> after your explanation of the power states, I now wonder, why you would need
>>>>>>> to power-down the device in jsa1212_suspend() and check, which parts need to
>>>>>>> be powered-up in jsa1212_resume(). The way I understand it, you only access
>>>>>>> the device to read data, after initialization. Therefor you power up the
>>>>>>> device, wait, read data and power down. All secured by a mutex. So, as long as
>>>>>>> no data is read, the device will always remain in low-power state.
>>>>>> Yes, What you mentioned is true for current use case. But once we implement
>>>>>> interrupt & IIO event support, We will have scenarios where the device is on
>>>>>> when suspend is triggered. I have just added the power management code with
>>>>>> that
>>>>>> scenario in mind.
>>>>> Please drop this for now and reintroduce it as and when it becomes relevant.
>>>>>
>>>>> If this had been part of a series that added support needing it in a later
>>>>> patch then it probably wouldn't have mattered (although it would still have
>>>>> been more correct in the patch that needed it).  Right now it adds complexity
>>>>> for no obvious gain.
>>>>>
>>>>> Also, once you have interrupt support etc you'll probably need to make changes
>>>>> to the current locations where you power up and down the chip anyway so it will
>>>>> fit in well then.
>>>>>
>>>>> Otherwise, a nice little driver.
>>>> When I answered Hartmut, I missed to consider the scenario where suspend to
>>>> ram gets triggered in the middle
>>>> of the read_raw() function.  When it happens our device might be "on" and
>>>> system might be trying to suspend.
>>>> So I think we still need the suspend/resume call to cover these cases.
>>> Do you agree with above comment ? If yes, I think there is no need to change
>>> this driver any more. Let me know.
>> Sorry, misread that as you'd identified an issue (which I hadn't noticed!)
>> and were going to fix and repost.
>>
>> Hmm. I'm not sure what the semantics of a suspend are.  I'd like to think it would
>> require no other function calls to be in flight, but not certain.
>>
>> Anyone else happen to know?
>>
> Suspend can happen asynchronously, so if it can happen before read raw
> can complete. There are OSs where suspend is automatically triggered, if
> no one blocks it using special locks, without even user process
> triggering suspend. Some users also define CONFIG_PREEMPT_VOLUNTARY.
> So Sathya do need to make sure that it power down in suspend callback or
> atleast prevent suspend to finish before read raw finishes the power
> down by using some mutexes.
>
> Thanks,
> Srinivas
>
>>>>> Thanks,
>>>>>
>>>>> Jonathan
>>>>>
>>>>>>>> Signed-off-by: Kuppuswamy Sathyanarayanan
>>>>>>>> <sathyanarayanan.kuppuswamy@linux.intel.com>
>>>>>>>> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
>>>>>>>> ---
>>>>>>>>     drivers/iio/light/Kconfig   |  10 +
>>>>>>>>     drivers/iio/light/Makefile  |   1 +
>>>>>>>>     drivers/iio/light/jsa1212.c | 471
>>>>>>>> ++++++++++++++++++++++++++++++++++++++++++++
>>>>>>>>     3 files changed, 482 insertions(+)
>>>>>>>>     create mode 100644 drivers/iio/light/jsa1212.c
>>>>>>>>
>>>>>>>> diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
>>>>>>>> index bf05ca5..b81d8a3 100644
>>>>>>>> --- a/drivers/iio/light/Kconfig
>>>>>>>> +++ b/drivers/iio/light/Kconfig
>>>>>>>> @@ -99,6 +99,16 @@ config HID_SENSOR_PROX
>>>>>>>>           To compile this driver as a module, choose M here: the
>>>>>>>>           module will be called hid-sensor-prox.
>>>>>>>>     +config JSA1212
>>>>>>>> +    tristate "JSA1212 ALS and proximity sensor driver"
>>>>>>>> +    depends on I2C
>>>>>>>> +    help
>>>>>>>> +     Say Y here if you want to build a IIO driver for JSA1212
>>>>>>>> +     proximity & ALS sensor device.
>>>>>>>> +
>>>>>>>> +     To compile this driver as a module, choose M here:
>>>>>>>> +     the module will be called jsa1212.
>>>>>>>> +
>>>>>>>>     config SENSORS_LM3533
>>>>>>>>         tristate "LM3533 ambient light sensor"
>>>>>>>>         depends on MFD_LM3533
>>>>>>>> diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
>>>>>>>> index 8b8c09f..23c6aa9 100644
>>>>>>>> --- a/drivers/iio/light/Makefile
>>>>>>>> +++ b/drivers/iio/light/Makefile
>>>>>>>> @@ -11,6 +11,7 @@ obj-$(CONFIG_GP2AP020A00F)    += gp2ap020a00f.o
>>>>>>>>     obj-$(CONFIG_HID_SENSOR_ALS)    += hid-sensor-als.o
>>>>>>>>     obj-$(CONFIG_HID_SENSOR_PROX)    += hid-sensor-prox.o
>>>>>>>>     obj-$(CONFIG_ISL29125)        += isl29125.o
>>>>>>>> +obj-$(CONFIG_JSA1212)        += jsa1212.o
>>>>>>>>     obj-$(CONFIG_SENSORS_LM3533)    += lm3533-als.o
>>>>>>>>     obj-$(CONFIG_LTR501)        += ltr501.o
>>>>>>>>     obj-$(CONFIG_SENSORS_TSL2563)    += tsl2563.o
>>>>>>>> diff --git a/drivers/iio/light/jsa1212.c b/drivers/iio/light/jsa1212.c
>>>>>>>> new file mode 100644
>>>>>>>> index 0000000..29de7e7
>>>>>>>> --- /dev/null
>>>>>>>> +++ b/drivers/iio/light/jsa1212.c
>>>>>>>> @@ -0,0 +1,471 @@
>>>>>>>> +/*
>>>>>>>> + * JSA1212 Ambient Light & Proximity Sensor Driver
>>>>>>>> + *
>>>>>>>> + * Copyright (c) 2014, Intel Corporation.
>>>>>>>> + *
>>>>>>>> + * This program is free software; you can redistribute it and/or modify it
>>>>>>>> + * under the terms and conditions of the GNU General Public License,
>>>>>>>> + * version 2, as published by the Free Software Foundation.
>>>>>>>> + *
>>>>>>>> + * This program is distributed in the hope it will be useful, but WITHOUT
>>>>>>>> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
>>>>>>>> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
>>>>>>>> + * more details.
>>>>>>>> + *
>>>>>>>> + * JSA1212 I2C slave address: 0x44(ADDR tied to GND), 0x45(ADDR tied to VDD)
>>>>>>>> + *
>>>>>>>> + * TODO: Interrupt support, thresholds, range support.
>>>>>>>> + */
>>>>>>>> +
>>>>>>>> +#include <linux/kernel.h>
>>>>>>>> +#include <linux/slab.h>
>>>>>>>> +#include <linux/module.h>
>>>>>>>> +#include <linux/delay.h>
>>>>>>>> +#include <linux/i2c.h>
>>>>>>>> +#include <linux/mutex.h>
>>>>>>>> +#include <linux/acpi.h>
>>>>>>>> +#include <linux/regmap.h>
>>>>>>>> +#include <linux/iio/iio.h>
>>>>>>>> +#include <linux/iio/sysfs.h>
>>>>>>>> +
>>>>>>>> +/* JSA1212 reg address */
>>>>>>>> +#define JSA1212_CONF_REG        0x01
>>>>>>>> +#define JSA1212_INT_REG            0x02
>>>>>>>> +#define JSA1212_PXS_LT_REG        0x03
>>>>>>>> +#define JSA1212_PXS_HT_REG        0x04
>>>>>>>> +#define JSA1212_ALS_TH1_REG        0x05
>>>>>>>> +#define JSA1212_ALS_TH2_REG        0x06
>>>>>>>> +#define JSA1212_ALS_TH3_REG        0x07
>>>>>>>> +#define JSA1212_PXS_DATA_REG        0x08
>>>>>>>> +#define JSA1212_ALS_DT1_REG        0x09
>>>>>>>> +#define JSA1212_ALS_DT2_REG        0x0A
>>>>>>>> +#define JSA1212_ALS_RNG_REG        0x0B
>>>>>>>> +#define JSA1212_MAX_REG            0x0C
>>>>>>>> +
>>>>>>>> +/* JSA1212 reg masks */
>>>>>>>> +#define JSA1212_CONF_MASK        0xFF
>>>>>>>> +#define JSA1212_INT_MASK        0xFF
>>>>>>>> +#define JSA1212_PXS_LT_MASK        0xFF
>>>>>>>> +#define JSA1212_PXS_HT_MASK        0xFF
>>>>>>>> +#define JSA1212_ALS_TH1_MASK        0xFF
>>>>>>>> +#define JSA1212_ALS_TH2_LT_MASK        0x0F
>>>>>>>> +#define JSA1212_ALS_TH2_HT_MASK        0xF0
>>>>>>>> +#define JSA1212_ALS_TH3_MASK        0xFF
>>>>>>>> +#define JSA1212_PXS_DATA_MASK        0xFF
>>>>>>>> +#define JSA1212_ALS_DATA_MASK        0x0FFF
>>>>>>>> +#define JSA1212_ALS_DT1_MASK        0xFF
>>>>>>>> +#define JSA1212_ALS_DT2_MASK        0x0F
>>>>>>>> +#define JSA1212_ALS_RNG_MASK        0x07
>>>>>>>> +
>>>>>>>> +/* JSA1212 CONF REG bits */
>>>>>>>> +#define JSA1212_CONF_PXS_MASK        0x80
>>>>>>>> +#define JSA1212_CONF_PXS_ENABLE        0x80
>>>>>>>> +#define JSA1212_CONF_PXS_DISABLE    0x00
>>>>>>>> +#define JSA1212_CONF_ALS_MASK        0x04
>>>>>>>> +#define JSA1212_CONF_ALS_ENABLE        0x04
>>>>>>>> +#define JSA1212_CONF_ALS_DISABLE    0x00
>>>>>>>> +#define JSA1212_CONF_IRDR_MASK        0x08
>>>>>>>> +/* Proxmity sensing IRDR current sink settings */
>>>>>>>> +#define JSA1212_CONF_IRDR_200MA        0x08
>>>>>>>> +#define JSA1212_CONF_IRDR_100MA        0x00
>>>>>>>> +#define JSA1212_CONF_PXS_SLP_MASK    0x70
>>>>>>>> +#define JSA1212_CONF_PXS_SLP_0MS    0x70
>>>>>>>> +#define JSA1212_CONF_PXS_SLP_12MS    0x60
>>>>>>>> +#define JSA1212_CONF_PXS_SLP_50MS    0x50
>>>>>>>> +#define JSA1212_CONF_PXS_SLP_75MS    0x40
>>>>>>>> +#define JSA1212_CONF_PXS_SLP_100MS    0x30
>>>>>>>> +#define JSA1212_CONF_PXS_SLP_200MS    0x20
>>>>>>>> +#define JSA1212_CONF_PXS_SLP_400MS    0x10
>>>>>>>> +#define JSA1212_CONF_PXS_SLP_800MS    0x00
>>>>>>>> +
>>>>>>>> +/* JSA1212 INT REG bits */
>>>>>>>> +#define JSA1212_INT_CTRL_MASK        0x01
>>>>>>>> +#define JSA1212_INT_CTRL_EITHER        0x00
>>>>>>>> +#define JSA1212_INT_CTRL_BOTH        0x01
>>>>>>>> +#define JSA1212_INT_ALS_PRST_MASK    0x06
>>>>>>>> +#define JSA1212_INT_ALS_PRST_1CONV    0x00
>>>>>>>> +#define JSA1212_INT_ALS_PRST_4CONV    0x02
>>>>>>>> +#define JSA1212_INT_ALS_PRST_8CONV    0x04
>>>>>>>> +#define JSA1212_INT_ALS_PRST_16CONV    0x06
>>>>>>>> +#define JSA1212_INT_ALS_FLAG_MASK    0x08
>>>>>>>> +#define JSA1212_INT_ALS_FLAG_CLR    0x00
>>>>>>>> +#define JSA1212_INT_PXS_PRST_MASK    0x60
>>>>>>>> +#define JSA1212_INT_PXS_PRST_1CONV    0x00
>>>>>>>> +#define JSA1212_INT_PXS_PRST_4CONV    0x20
>>>>>>>> +#define JSA1212_INT_PXS_PRST_8CONV    0x40
>>>>>>>> +#define JSA1212_INT_PXS_PRST_16CONV    0x60
>>>>>>>> +#define JSA1212_INT_PXS_FLAG_MASK    0x80
>>>>>>>> +#define JSA1212_INT_PXS_FLAG_CLR    0x00
>>>>>>>> +
>>>>>>>> +/* JSA1212 ALS RNG REG bits */
>>>>>>>> +#define JSA1212_ALS_RNG_0_2048        0x00
>>>>>>>> +#define JSA1212_ALS_RNG_0_1024        0x01
>>>>>>>> +#define JSA1212_ALS_RNG_0_512        0x02
>>>>>>>> +#define JSA1212_ALS_RNG_0_256        0x03
>>>>>>>> +#define JSA1212_ALS_RNG_0_128        0x04
>>>>>>>> +
>>>>>>>> +/* JSA1212 INT threshold range */
>>>>>>>> +#define JSA1212_ALS_TH_MIN    0x0000
>>>>>>>> +#define JSA1212_ALS_TH_MAX    0x0FFF
>>>>>>>> +#define JSA1212_PXS_TH_MIN    0x00
>>>>>>>> +#define JSA1212_PXS_TH_MAX    0xFF
>>>>>>>> +
>>>>>>>> +#define JSA1212_ALS_DELAY_MS    200
>>>>>>>> +#define JSA1212_PXS_DELAY_MS    100
>>>>>>>> +
>>>>>>>> +#define JSA1212_DRIVER_NAME    "jsa1212"
>>>>>>>> +#define JSA1212_REGMAP_NAME    "jsa1212_regmap"
>>>>>>>> +
>>>>>>>> +enum jsa1212_op_mode {
>>>>>>>> +    JSA1212_OPMODE_ALS_EN,
>>>>>>>> +    JSA1212_OPMODE_PXS_EN,
>>>>>>>> +};
>>>>>>>> +
>>>>>>>> +struct jsa1212_data {
>>>>>>>> +    struct i2c_client *client;
>>>>>>>> +    struct mutex lock;
>>>>>>>> +    u8 als_rng_idx;
>>>>>>>> +    bool als_en; /* ALS enable status */
>>>>>>>> +    bool pxs_en; /* proximity enable status */
>>>>>>>> +    struct regmap *regmap;
>>>>>>>> +};
>>>>>>>> +
>>>>>>>> +/* ALS range idx to val mapping */
>>>>>>>> +static const int jsa1212_als_range_val[] = {2048, 1024, 512, 256, 128,
>>>>>>>> +                        128, 128, 128};
>>>>>>>> +
>>>>>>>> +/* Enables or disables ALS function based on status */
>>>>>>>> +static int jsa1212_als_enable(struct jsa1212_data *data, u8 status)
>>>>>>>> +{
>>>>>>>> +    int ret;
>>>>>>>> +
>>>>>>>> +    ret = regmap_update_bits(data->regmap, JSA1212_CONF_REG,
>>>>>>>> +                JSA1212_CONF_ALS_MASK,
>>>>>>>> +                status);
>>>>>>>> +    if (ret < 0)
>>>>>>>> +        return ret;
>>>>>>>> +
>>>>>>>> +    data->als_en = !!status;
>>>>>>>> +
>>>>>>>> +    return 0;
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +/* Enables or disables PXS function based on status */
>>>>>>>> +static int jsa1212_pxs_enable(struct jsa1212_data *data, u8 status)
>>>>>>>> +{
>>>>>>>> +    int ret;
>>>>>>>> +
>>>>>>>> +    ret = regmap_update_bits(data->regmap, JSA1212_CONF_REG,
>>>>>>>> +                JSA1212_CONF_PXS_MASK,
>>>>>>>> +                status);
>>>>>>>> +    if (ret < 0)
>>>>>>>> +        return ret;
>>>>>>>> +
>>>>>>>> +    data->pxs_en = !!status;
>>>>>>>> +
>>>>>>>> +    return 0;
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +static int jsa1212_read_als_data(struct jsa1212_data *data,
>>>>>>>> +                unsigned int *val)
>>>>>>>> +{
>>>>>>>> +    int ret;
>>>>>>>> +    __le16 als_data;
>>>>>>>> +
>>>>>>>> +    ret = jsa1212_als_enable(data, JSA1212_CONF_ALS_ENABLE);
>>>>>>>> +    if (ret < 0)
>>>>>>>> +        return ret;
>>>>>>>> +
>>>>>>>> +    /* Delay for data output */
>>>>>>>> +    msleep(JSA1212_ALS_DELAY_MS);
>>>>>>>> +
>>>>>>>> +    /* Read 12 bit data */
>>>>>>>> +    ret = regmap_bulk_read(data->regmap, JSA1212_ALS_DT1_REG, &als_data, 2);
>>>>>>>> +    if (ret < 0) {
>>>>>>>> +        dev_err(&data->client->dev, "als data read err\n");
>>>>>>>> +        goto als_data_read_err;
>>>>>>>> +    }
>>>>>>>> +
>>>>>>>> +    *val = le16_to_cpu(als_data);
>>>>>>>> +
>>>>>>>> +als_data_read_err:
>>>>>>>> +    return jsa1212_als_enable(data, JSA1212_CONF_ALS_DISABLE);
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +static int jsa1212_read_pxs_data(struct jsa1212_data *data,
>>>>>>>> +                unsigned int *val)
>>>>>>>> +{
>>>>>>>> +    int ret;
>>>>>>>> +    unsigned int pxs_data;
>>>>>>>> +
>>>>>>>> +    ret = jsa1212_pxs_enable(data, JSA1212_CONF_PXS_ENABLE);
>>>>>>>> +    if (ret < 0)
>>>>>>>> +        return ret;
>>>>>>>> +
>>>>>>>> +    /* Delay for data output */
>>>>>>>> +    msleep(JSA1212_PXS_DELAY_MS);
>>>>>>>> +
>>>>>>>> +    /* Read out all data */
>>>>>>>> +    ret = regmap_read(data->regmap, JSA1212_PXS_DATA_REG, &pxs_data);
>>>>>>>> +    if (ret < 0) {
>>>>>>>> +        dev_err(&data->client->dev, "pxs data read err\n");
>>>>>>>> +        goto pxs_data_read_err;
>>>>>>>> +    }
>>>>>>>> +
>>>>>>>> +    *val = pxs_data & JSA1212_PXS_DATA_MASK;
>>>>>>>> +
>>>>>>>> +pxs_data_read_err:
>>>>>>>> +    return jsa1212_pxs_enable(data, JSA1212_CONF_PXS_DISABLE);
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +static int jsa1212_read_raw(struct iio_dev *indio_dev,
>>>>>>>> +                struct iio_chan_spec const *chan,
>>>>>>>> +                int *val, int *val2, long mask)
>>>>>>>> +{
>>>>>>>> +    int ret;
>>>>>>>> +    struct jsa1212_data *data = iio_priv(indio_dev);
>>>>>>>> +
>>>>>>>> +    switch (mask) {
>>>>>>>> +    case IIO_CHAN_INFO_RAW:
>>>>>>>> +        mutex_lock(&data->lock);
>>>>>>>> +        switch (chan->type) {
>>>>>>>> +        case IIO_LIGHT:
>>>>>>>> +            ret = jsa1212_read_als_data(data, val);
>>>>>>>> +            break;
>>>>>>>> +        case IIO_PROXIMITY:
>>>>>>>> +            ret = jsa1212_read_pxs_data(data, val);
>>>>>>>> +            break;
>>>>>>>> +        default:
>>>>>>>> +            ret = -EINVAL;
>>>>>>>> +            break;
>>>>>>>> +        }
>>>>>>>> +        mutex_unlock(&data->lock);
>>>>>>>> +        return ret < 0 ? ret : IIO_VAL_INT;
>>>>>>>> +    case IIO_CHAN_INFO_SCALE:
>>>>>>>> +        switch (chan->type) {
>>>>>>>> +        case IIO_LIGHT:
>>>>>>>> +            *val = jsa1212_als_range_val[data->als_rng_idx];
>>>>>>>> +            *val2 = BIT(12); /* Max 12 bit value */
>>>>>>>> +            return IIO_VAL_FRACTIONAL;
>>>>>>>> +        default:
>>>>>>>> +            break;
>>>>>>>> +        }
>>>>>>>> +        break;
>>>>>>>> +    default:
>>>>>>>> +        break;
>>>>>>>> +    }
>>>>>>>> +
>>>>>>>> +    return -EINVAL;
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +static const struct iio_chan_spec jsa1212_channels[] = {
>>>>>>>> +    {
>>>>>>>> +        .type = IIO_LIGHT,
>>>>>>>> +        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
>>>>>>>> +            BIT(IIO_CHAN_INFO_SCALE),
>>>>>>>> +    },
>>>>>>>> +    {
>>>>>>>> +        .type = IIO_PROXIMITY,
>>>>>>>> +        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
>>>>>>>> +    }
>>>>>>>> +};
>>>>>>>> +
>>>>>>>> +static const struct iio_info jsa1212_info = {
>>>>>>>> +    .driver_module        = THIS_MODULE,
>>>>>>>> +    .read_raw        = &jsa1212_read_raw,
>>>>>>>> +};
>>>>>>>> +
>>>>>>>> +static int jsa1212_chip_init(struct jsa1212_data *data)
>>>>>>>> +{
>>>>>>>> +    int ret;
>>>>>>>> +
>>>>>>>> +    ret = regmap_write(data->regmap, JSA1212_CONF_REG,
>>>>>>>> +                (JSA1212_CONF_PXS_SLP_50MS |
>>>>>>>> +                JSA1212_CONF_IRDR_200MA));
>>>>>>>> +    if (ret < 0)
>>>>>>>> +        return ret;
>>>>>>>> +
>>>>>>>> +    ret = regmap_write(data->regmap, JSA1212_INT_REG,
>>>>>>>> +                JSA1212_INT_ALS_PRST_4CONV);
>>>>>>>> +    if (ret < 0)
>>>>>>>> +        return ret;
>>>>>>>> +
>>>>>>>> +    data->als_rng_idx = JSA1212_ALS_RNG_0_2048;
>>>>>>>> +
>>>>>>>> +    return 0;
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +static bool jsa1212_is_volatile_reg(struct device *dev, unsigned int reg)
>>>>>>>> +{
>>>>>>>> +    switch (reg) {
>>>>>>>> +    case JSA1212_PXS_DATA_REG:
>>>>>>>> +    case JSA1212_ALS_DT1_REG:
>>>>>>>> +    case JSA1212_ALS_DT2_REG:
>>>>>>>> +    case JSA1212_INT_REG:
>>>>>>>> +        return true;
>>>>>>>> +    default:
>>>>>>>> +        return false;
>>>>>>>> +    }
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +static struct regmap_config jsa1212_regmap_config = {
>>>>>>>> +    .name =  JSA1212_REGMAP_NAME,
>>>>>>>> +    .reg_bits = 8,
>>>>>>>> +    .val_bits = 8,
>>>>>>>> +    .max_register = JSA1212_MAX_REG,
>>>>>>>> +    .cache_type = REGCACHE_RBTREE,
>>>>>>>> +    .volatile_reg = jsa1212_is_volatile_reg,
>>>>>>>> +};
>>>>>>>> +
>>>>>>>> +static int jsa1212_probe(struct i2c_client *client,
>>>>>>>> +             const struct i2c_device_id *id)
>>>>>>>> +{
>>>>>>>> +    struct jsa1212_data *data;
>>>>>>>> +    struct iio_dev *indio_dev;
>>>>>>>> +    struct regmap *regmap;
>>>>>>>> +    int ret;
>>>>>>>> +
>>>>>>>> +    if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
>>>>>>>> +        return -ENODEV;
>>>>>>>> +
>>>>>>>> +    indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
>>>>>>>> +    if (!indio_dev)
>>>>>>>> +        return -ENOMEM;
>>>>>>>> +
>>>>>>>> +    regmap = devm_regmap_init_i2c(client, &jsa1212_regmap_config);
>>>>>>>> +    if (IS_ERR(regmap)) {
>>>>>>>> +        dev_err(&client->dev, "Regmap initialization failed.\n");
>>>>>>>> +        return PTR_ERR(regmap);
>>>>>>>> +    }
>>>>>>>> +
>>>>>>>> +    data = iio_priv(indio_dev);
>>>>>>>> +
>>>>>>>> +    i2c_set_clientdata(client, indio_dev);
>>>>>>>> +    data->client = client;
>>>>>>>> +    data->regmap = regmap;
>>>>>>>> +
>>>>>>>> +    mutex_init(&data->lock);
>>>>>>>> +
>>>>>>>> +    ret = jsa1212_chip_init(data);
>>>>>>>> +    if (ret < 0)
>>>>>>>> +        return ret;
>>>>>>>> +
>>>>>>>> +    indio_dev->dev.parent = &client->dev;
>>>>>>>> +    indio_dev->channels = jsa1212_channels;
>>>>>>>> +    indio_dev->num_channels = ARRAY_SIZE(jsa1212_channels);
>>>>>>>> +    indio_dev->name = JSA1212_DRIVER_NAME;
>>>>>>>> +    indio_dev->modes = INDIO_DIRECT_MODE;
>>>>>>>> +
>>>>>>>> +    indio_dev->info = &jsa1212_info;
>>>>>>>> +
>>>>>>>> +    ret = iio_device_register(indio_dev);
>>>>>>>> +    if (ret < 0)
>>>>>>>> +        dev_err(&client->dev, "%s: register device failed\n", __func__);
>>>>>>>> +
>>>>>>>> +    return ret;
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> + /* power off the device */
>>>>>>>> +static int jsa1212_power_off(struct jsa1212_data *data)
>>>>>>>> +{
>>>>>>>> +    int ret;
>>>>>>>> +
>>>>>>>> +    mutex_lock(&data->lock);
>>>>>>>> +
>>>>>>>> +    ret = regmap_update_bits(data->regmap, JSA1212_CONF_REG,
>>>>>>>> +                JSA1212_CONF_ALS_MASK |
>>>>>>>> +                JSA1212_CONF_PXS_MASK,
>>>>>>>> +                JSA1212_CONF_ALS_DISABLE |
>>>>>>>> +                JSA1212_CONF_PXS_DISABLE);
>>>>>>>> +
>>>>>>>> +    if (ret < 0)
>>>>>>>> +        dev_err(&data->client->dev, "power off cmd failed\n");
>>>>>>>> +
>>>>>>>> +    mutex_unlock(&data->lock);
>>>>>>>> +
>>>>>>>> +    return ret;
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +static int jsa1212_remove(struct i2c_client *client)
>>>>>>>> +{
>>>>>>>> +    struct iio_dev *indio_dev = i2c_get_clientdata(client);
>>>>>>>> +    struct jsa1212_data *data = iio_priv(indio_dev);
>>>>>>>> +
>>>>>>>> +    iio_device_unregister(indio_dev);
>>>>>>>> +
>>>>>>>> +    return jsa1212_power_off(data);
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +#ifdef CONFIG_PM_SLEEP
>>>>>>>> +static int jsa1212_suspend(struct device *dev)
>>>>>>>> +{
>>>>>>>> +    struct jsa1212_data *data;
>>>>>>>> +
>>>>>>>> +    data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
>>>>>>>> +
>>>>>>>> +    return jsa1212_power_off(data);
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +static int jsa1212_resume(struct device *dev)
>>>>>>>> +{
>>>>>>>> +    int ret = 0;
>>>>>>>> +    struct jsa1212_data *data;
>>>>>>>> +
>>>>>>>> +    data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
>>>>>>>> +
>>>>>>>> +    mutex_lock(&data->lock);
>>>>>>>> +
>>>>>>>> +    if (data->als_en) {
>>>>>>>> +        ret = jsa1212_als_enable(data, JSA1212_CONF_ALS_ENABLE);
>>>>>>>> +        if (ret < 0) {
>>>>>>>> +            dev_err(dev, "als resume failed\n");
>>>>>>>> +            goto unlock_and_ret;
>>>>>>>> +        }
>>>>>>>> +    }
>>>>>>>> +
>>>>>>>> +    if (data->pxs_en) {
>>>>>>>> +        ret = jsa1212_pxs_enable(data, JSA1212_CONF_PXS_ENABLE);
>>>>>>>> +        if (ret < 0)
>>>>>>>> +            dev_err(dev, "pxs resume failed\n");
>>>>>>>> +    }
>>>>>>>> +
>>>>>>>> +unlock_and_ret:
>>>>>>>> +    mutex_unlock(&data->lock);
>>>>>>>> +    return ret;
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +static SIMPLE_DEV_PM_OPS(jsa1212_pm_ops, jsa1212_suspend, jsa1212_resume);
>>>>>>>> +
>>>>>>>> +#define JSA1212_PM_OPS (&jsa1212_pm_ops)
>>>>>>>> +#else
>>>>>>>> +#define JSA1212_PM_OPS NULL
>>>>>>>> +#endif
>>>>>>>> +
>>>>>>>> +static const struct acpi_device_id jsa1212_acpi_match[] = {
>>>>>>>> +    {"JSA1212", 0},
>>>>>>>> +    { },
>>>>>>>> +};
>>>>>>>> +MODULE_DEVICE_TABLE(acpi, jsa1212_acpi_match);
>>>>>>>> +
>>>>>>>> +static const struct i2c_device_id jsa1212_id[] = {
>>>>>>>> +    { JSA1212_DRIVER_NAME, 0 },
>>>>>>>> +    { }
>>>>>>>> +};
>>>>>>>> +MODULE_DEVICE_TABLE(i2c, jsa1212_id);
>>>>>>>> +
>>>>>>>> +static struct i2c_driver jsa1212_driver = {
>>>>>>>> +    .driver = {
>>>>>>>> +        .name    = JSA1212_DRIVER_NAME,
>>>>>>>> +        .pm    = JSA1212_PM_OPS,
>>>>>>>> +        .owner    = THIS_MODULE,
>>>>>>>> +        .acpi_match_table = ACPI_PTR(jsa1212_acpi_match),
>>>>>>>> +    },
>>>>>>>> +    .probe        = jsa1212_probe,
>>>>>>>> +    .remove        = jsa1212_remove,
>>>>>>>> +    .id_table    = jsa1212_id,
>>>>>>>> +};
>>>>>>>> +module_i2c_driver(jsa1212_driver);
>>>>>>>> +
>>>>>>>> +MODULE_AUTHOR("Sathya Kuppuswamy
>>>>>>>> <sathyanarayanan.kuppuswamy@linux.intel.com>");
>>>>>>>> +MODULE_DESCRIPTION("JSA1212 proximity/ambient light sensor driver");
>>>>>>>> +MODULE_LICENSE("GPL v2");
>>>>>>>>
>
>

-- 
Sathyanarayanan Kuppuswamy
Android kernel developer