Re: [PATCH V1 1/1] iio: add Capella cm3218x ambient light sensor driver.

Re: [PATCH V1 1/1] iio: add Capella cm3218x ambient light sensor driver.

[Jonathan Cameron]

On March 20, 2014 11:19:49 PM GMT+00:00, Srinivas Pandruvada <srinivas.pandruvada-VuQAYsv1563Yd54FQh9/CA@public.gmane.org> wrote:
>On 03/19/2014 11:54 PM, Jonathan Cameron wrote:
>>
>> On March 20, 2014 12:58:02 AM GMT+00:00, Kevin Tsai
><ktsai-GubuWUlQtMwciDkP5Hr2oA@public.gmane.org> wrote:
>>> Hi Peter,
>>>
>>> Thanks for your advise.  I'll update my code.
>>>
>>> ACPI is optional.  Most PC manufactory may store the lens factor to
>>> ACPI
>>> table.  But, phone customers like to modify the parameters inside
>code.
>>>
>>> CM3218 have two versions.  The old version need to read SMBus ARA
>>> register
>>> to clean interrupt.  That's why I need to change I2C chip address.
>>> Please
>>> guid me if you have a better way to access two addresses.
>> Would the smbus alert infrastructure in drivers/i2ç/i2c-smbus.c help?
>The smbus alert notification are based on the underlying i2c
>controller.
>Not every controller supports. I can see only one controller driver in
>the upstream Linux added this support.

To my mind adding wider support for the alert functionality will be the way forward.

Wolfram, any idea why so few bus drivers implement the smbus alert stuff? I would
 guess you won't be against wider support of this using existing infrastructure?
>
>Thanks,
>Srinivas
>
>>> Thanks.
>>>
>>> Kevin Tsai
>>> 03/19/14
>>>
>>> ----- Original Message -----
>>> From: "Peter Meerwald" <pmeerw-jW+XmwGofnusTnJN9+BGXg@public.gmane.org>
>>> To: "Kevin Tsai" <ktsai-GubuWUlQtMwciDkP5Hr2oA@public.gmane.org>
>>> Cc: "Jonathan Cameron" <jic23-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>;
><linux-iio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
>>> Sent: Wednesday, March 19, 2014 11:07
>>> Subject: Re: [PATCH V1 1/1] iio: add Capella cm3218x ambient light
>>> sensor
>>> driver.
>>>
>>>
>>>>> Add Capella Microsystem CM3218x family Ambient Light Sensor IIO
>>> driver.
>>>>> This driver will convert raw data to lux value.  Default
>parameters
>>> are
>>>>> for reference only.  It will detect ACPI table to load per-system
>>>>> manufacturing
>>>>> parameters.
>>>> nitpicking below
>>>>
>>>>> ---
>>>>>   .../devicetree/bindings/i2c/trivial-devices.txt    |   1 +
>>>>>   drivers/iio/light/Kconfig                          |  11 +
>>>>>   drivers/iio/light/Makefile                         |   1 +
>>>>>   drivers/iio/light/cm3218x.c                        | 769
>>>>> +++++++++++++++++++++
>>>>>   4 files changed, 782 insertions(+)
>>>>>   create mode 100644 drivers/iio/light/cm3218x.c
>>>>>
>>>>> diff --git
>>> a/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>>>>> b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>>>>> index 1a1ac2e..29e7eae 100644
>>>>> --- a/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>>>>> +++ b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>>>>> @@ -17,6 +17,7 @@ at,24c08 i2c serial eeprom  (24cxx)
>>>>>   atmel,24c02 i2c serial eeprom  (24cxx)
>>>>>   atmel,at97sc3204t i2c trusted platform module (TPM)
>>>>>   capella,cm32181 CM32181: Ambient Light Sensor
>>>>> +capella,cm3218x CM3218x: Ambient Light Sensor
>>>>>   catalyst,24c32 i2c serial eeprom
>>>>>   dallas,ds1307 64 x 8, Serial, I2C Real-Time Clock
>>>>>   dallas,ds1338 I2C RTC with 56-Byte NV RAM
>>>>> diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
>>>>> index d12b2a0..45a22a6 100644
>>>>> --- a/drivers/iio/light/Kconfig
>>>>> +++ b/drivers/iio/light/Kconfig
>>>>> @@ -38,6 +38,17 @@ config CM32181
>>>>>   To compile this driver as a module, choose M here:
>>>>>   the module will be called cm32181.
>>>>>
>>>>> +config CM3218X
>>>>> + depends on I2C
>>>> is there an ACPI dependency?
>>>>
>>>>> + tristate "CM3218x driver"
>>>>> + help
>>>>> + Say Y here if you use cm3218x.
>>>>> + This option enables ambient light sensor using
>>>>> + Capella cm3218x device driver.
>>>>> +
>>>>> + To compile this driver as a module, choose M here:
>>>>> + the module will be called cm3218x.
>>>>> +
>>>>>   config CM36651
>>>>>   depends on I2C
>>>>>   tristate "CM36651 driver"
>>>>> diff --git a/drivers/iio/light/Makefile
>b/drivers/iio/light/Makefile
>>>>> index 60e35ac..a506c23 100644
>>>>> --- a/drivers/iio/light/Makefile
>>>>> +++ b/drivers/iio/light/Makefile
>>>>> @@ -6,6 +6,7 @@
>>>>>   obj-$(CONFIG_ADJD_S311) += adjd_s311.o
>>>>>   obj-$(CONFIG_APDS9300) += apds9300.o
>>>>>   obj-$(CONFIG_CM32181) += cm32181.o
>>>>> +obj-$(CONFIG_CM3218X) += cm3218x.o
>>>>>   obj-$(CONFIG_CM36651) += cm36651.o
>>>>>   obj-$(CONFIG_GP2AP020A00F) += gp2ap020a00f.o
>>>>>   obj-$(CONFIG_HID_SENSOR_ALS) += hid-sensor-als.o
>>>>> diff --git a/drivers/iio/light/cm3218x.c
>>> b/drivers/iio/light/cm3218x.c
>>>>> new file mode 100644
>>>>> index 0000000..e422f68
>>>>> --- /dev/null
>>>>> +++ b/drivers/iio/light/cm3218x.c
>>>>> @@ -0,0 +1,769 @@
>>>>> +/*
>>>>> + * Copyright (C) 2014 Capella Microsystems Inc.
>>>>> + * Author: Kevin Tsai <ktsai-GubuWUlQtMwciDkP5Hr2oA@public.gmane.org>
>>>>> + *
>>>>> + * This program is free software; you can redistribute it and/or
>>> modify
>>>>> it
>>>>> + * under the terms of the GNU General Public License version 2,
>as
>>>>> published
>>>>> + * by the Free Software Foundation.
>>>>> + *
>>>>> + * Special thanks Srinivas Pandruvada
>>>>> <srinivas.pandruvada-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
>>>>> + * help to add ACPI support.
>>>>> + *
>>>>> + */
>>>>> +
>>>>> +#include <linux/delay.h>
>>>>> +#include <linux/err.h>
>>>>> +#include <linux/i2c.h>
>>>>> +#include <linux/mutex.h>
>>>>> +#include <linux/module.h>
>>>>> +#include <linux/interrupt.h>
>>>>> +#include <linux/regulator/consumer.h>
>>>>> +#include <linux/iio/iio.h>
>>>>> +#include <linux/iio/sysfs.h>
>>>>> +#include <linux/iio/events.h>
>>>>> +#include <linux/init.h>
>>>>> +#include <linux/acpi.h>
>>>>> +
>>>>> +/* Registers Address */
>>>>> +#define CM3218x_REG_ADDR_CMD 0x00
>>>>> +#define CM3218x_REG_ADDR_WH 0x01
>>>>> +#define CM3218x_REG_ADDR_WL 0x02
>>>>> +#define CM3218x_REG_ADDR_TEST 0x03
>>>> inconsistent whitespace allover
>>>>
>>>>> +#define CM3218x_REG_ADDR_ALS 0x04
>>>>> +#define CM3218x_REG_ADDR_STATUS 0x06
>>>>> +#define CM3218x_REG_ADDR_ID 0x07
>>>>> +
>>>>> +/* Number of Configurable Registers */
>>>>> +#define CM3218x_CONF_REG_NUM 16
>>>>> +
>>>>> +/* CMD register */
>>>>> +#define CM3218x_CMD_ALS_DISABLE 0x01
>>>>> +#define CM3218x_CMD_ALS_INT_EN 0x02
>>>>> +#define CM3218x_CMD_ALS_THRES_WINDOW 0x04
>>>>> +
>>>>> +#define CM3218x_CMD_ALS_PERS_SHIFT 4
>>>>> +#define CM3218x_CMD_ALS_PERS_MASK (0x03 <<
>>> CM3218x_CMD_ALS_PERS_SHIFT)
>>>>> +#define CM3218x_CMD_ALS_PERS_DEFAULT (0x01 <<
>>>>> CM3218x_CMD_ALS_PERS_SHIFT)
>>>>> +
>>>>> +#define CM3218x_CMD_ALS_IT_SHIFT 6
>>>>> +#define CM3218x_CMD_ALS_IT_MASK (0x0F <<
>CM3218x_CMD_ALS_IT_SHIFT)
>>>>> +#define CM3218x_CMD_ALS_IT_DEFAULT (0x01 <<
>>> CM3218x_CMD_ALS_IT_SHIFT)
>>>>> +
>>>>> +#define CM3218x_CMD_ALS_HS_SHIFT 11
>>>>> +#define CM3218x_CMD_ALS_HS_MASK (0x01 <<
>CM3218x_CMD_ALS_HS_SHIFT)
>>>>> +#define CM3218x_CMD_ALS_HS_DEFAULT (0x00 <<
>>> CM3218x_CMD_ALS_HS_SHIFT)
>>>>> +
>>>>> +#define CM3218x_CMD_DEFAULT (CM3218x_CMD_ALS_THRES_WINDOW |\
>>>>> + CM3218x_CMD_ALS_PERS_DEFAULT |\
>>>>> + CM3218x_CMD_ALS_IT_DEFAULT |\
>>>>> + CM3218x_CMD_ALS_HS_DEFAULT)
>>>>> +
>>>>> +#define CM3218x_WH_DEFAULT 0xFFFF
>>>>> +#define CM3218x_WL_DEFAULT 0x0000
>>>>> +
>>>>> +#define CM3218x_CALIBSCALE_DEFAULT 100000
>>>>> +#define CM3218x_CALIBSCALE_RESOLUTION 100000
>>>>> +#define MLUX_PER_LUX 1000
>>>> CM3218x prefix missing
>>>>
>>>> the lowercase x in macros is a bit weird for my taste
>>>>
>>>>> +#define CM3218x_THRESHOLD_PERCENT 10 /* 10 percent */
>>>>> +
>>>>> +/* CM3218 Family */
>>>>> +#define CM3218_MLUX_PER_BIT_DEFAULT 5 /* Depend on system */
>>>>> +#define CM3218_MLUX_PER_BIT_BASE_IT 800000
>>>>> +static int CM3218_als_it_bits[] = {0, 1, 2, 3};
>>>>> +static int CM3218_als_it_values[] = {100000, 200000, 400000,
>>> 800000};
>>>> const missing
>>>>
>>>>> +
>>>>> +/* CM32181 Family */
>>>>> +#define CM32181_MLUX_PER_BIT_DEFAULT 5
>>>>> +#define CM32181_MLUX_PER_BIT_BASE_IT 800000
>>>>> +static int CM32181_als_it_bits[] = {12, 8, 0, 1, 2, 3};
>>>>> +static int CM32181_als_it_values[] = {
>>>>> + 25000, 50000, 100000, 200000, 400000, 800000};
>>>> const missing
>>>>
>>>>> +
>>>>> +/* CM32182 Family */
>>>>> +#define CM32182_MLUX_PER_BIT_DEFAULT 5
>>>>> +#define CM32182_MLUX_PER_BIT_BASE_IT 800000
>>>>> +static int CM32182_als_it_bits[] = {12, 8, 0, 1, 2, 3};
>>>>> +static int CM32182_als_it_values[] = {
>>>>> + 25000, 50000, 100000, 200000, 400000, 800000};
>>>> const missing
>>>>
>>>> these definitions are largely identical and could be dropped; they
>>> are
>>>> only used to fill device-specific tables below; why have a separate
>>>> define here?
>>>>
>>>>> +
>>>>> +struct cmdev {
>>>> prefix?
>>>>
>>>>> + u32 family_id;
>>>>> + int int_type;
>>>>> +#define INT_TYPE_SMBUS 0
>>>>> +#define INT_TYPE_I2C 1
>>>> prefix?
>>>>
>>>>> + int regs_bmp;
>>>>> + int calibscale;
>>>>> + int mlux_per_bit;
>>>>> + int mlux_per_bit_base_it;
>>>>> + int *als_it_bits;
>>>>> + int *als_it_values;
>>>>> + int num_als_it;
>>>>> +};
>>>>> +
>>>>> +static struct cmdev cm3218 = {
>>>>> + 3218, INT_TYPE_SMBUS, 0x0F, CM3218x_CALIBSCALE_DEFAULT,
>>>>> + CM3218_MLUX_PER_BIT_DEFAULT, CM3218_MLUX_PER_BIT_BASE_IT,
>>>>> + CM3218_als_it_bits, CM3218_als_it_values,
>>>>> + ARRAY_SIZE(CM3218_als_it_bits)};
>>>>> +
>>>>> +static struct cmdev cm32181 = {
>>>>> + 32181, INT_TYPE_I2C, 0x0F, CM3218x_CALIBSCALE_DEFAULT,
>>>>> + CM32181_MLUX_PER_BIT_DEFAULT, CM32181_MLUX_PER_BIT_BASE_IT,
>>>>> + CM32181_als_it_bits, CM32181_als_it_values,
>>>>> + ARRAY_SIZE(CM32181_als_it_bits)};
>>>>> +
>>>>> +static struct cmdev cm32182 = {
>>>>> + 32182, INT_TYPE_I2C, 0x0F, CM3218x_CALIBSCALE_DEFAULT,
>>>>> + CM32182_MLUX_PER_BIT_DEFAULT, CM32182_MLUX_PER_BIT_BASE_IT,
>>>>> + CM32182_als_it_bits, CM32182_als_it_values,
>>>>> + ARRAY_SIZE(CM32182_als_it_bits)};
>>>>> +
>>>>> +struct cm3218x_chip {
>>>>> + struct i2c_client *client;
>>>>> + struct cmdev *cmdev;
>>>>> + struct mutex lock;
>>>>> + u16 conf_regs[CM3218x_CONF_REG_NUM];
>>>>> + int als_raw;
>>>>> +};
>>>>> +
>>>>> +static int cm3218x_get_lux(struct cm3218x_chip *chip);
>>>>> +static int cm3218x_threshold_update(struct cm3218x_chip *chip,
>int
>>>>> percent);
>>>>> +static int cm3218x_read_als_it(struct cm3218x_chip *chip, int
>>> *val2);
>>>>> +
>>>>> +/**
>>>>> + * cm3218x_read_ara() - Read ARA register
>>>>> + * @cm3218x: pointer of struct cm3218x.
>>>> @chip
>>>>
>>>>> + *
>>>>> + * Following SMBus protocol, ARA register is available only when
>>>>> interrupt
>>>>> + * event happened.  Read it to clean interrupt event.  Otherwise,
>>> other
>>>>> + * device address/registers will be blocked during interrupt
>event.
>>>>> + *
>>>>> + * Return: 0 for success; otherwise for error code.
>>>>> + */
>>>>> +static int cm3218x_read_ara(struct cm3218x_chip *chip)
>>>>> +{
>>>>> + struct i2c_client *client = chip->client;
>>>>> + int status;
>>>>> + unsigned short addr;
>>>>> +
>>>> this looks dangerous: temporarily changing the I2C chip address!
>>>>
>>>>> + addr = client->addr;
>>>>> + client->addr = 0x0C;
>>>>> + status = i2c_smbus_read_byte(client);
>>>>> + client->addr = addr;
>>>>> +
>>>>> + if (status < 0)
>>>>> + return -ENODEV;
>>>>> +
>>>>> + return status;
>>>>> +}
>>>>> +
>>>>> +/**
>>>>> + * cm3218x_interrupt_config() - Enable/Disable CM3218x interrupt
>>>>> + * @cm3218x: pointer of struct cm3218x.
>>>> @chip: pointer to struct cm3218x_chip
>>>>
>>>>> + * @enable: 0 to disable; otherwise to enable
>>>>> + *
>>>>> + * Config CM3218x interrupt control bit.
>>>>> + *
>>>>> + * Return: 0 for success; otherwise for error code.
>>>>> + */
>>>>> +static int cm3218x_interrupt_config(struct cm3218x_chip *chip,
>int
>>>>> enable)
>>>>> +{
>>>>> + struct i2c_client *client = chip->client;
>>>>> + struct cmdev *cmdev = chip->cmdev;
>>>>> + int status;
>>>>> +
>>>>> + if (!cmdev)
>>>>> + return -ENODEV;
>>>>> +
>>>>> + /* Force to clean interrupt */
>>>>> + if (cmdev->int_type == INT_TYPE_I2C) {
>>>>> + status = i2c_smbus_read_word_data(client,
>>>>> + CM3218x_REG_ADDR_STATUS);
>>>>> + if (status < 0)
>>>>> + cmdev->int_type = INT_TYPE_SMBUS;
>>>>> + }
>>>>> + if (cmdev->int_type == INT_TYPE_SMBUS)
>>>>> + cm3218x_read_ara(chip);
>>>>> +
>>>>> + if (enable)
>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD] |=
>>>>> + CM3218x_CMD_ALS_INT_EN;
>>>>> + else
>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD] &=
>>>>> + ~CM3218x_CMD_ALS_INT_EN;
>>>>> +
>>>>> + status = i2c_smbus_write_word_data(client, CM3218x_REG_ADDR_CMD,
>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD]);
>>>>> +
>>>>> + if (status < 0)
>>>>> + return -ENODEV;
>>>>> +
>>>>> + return status;
>>>>> +}
>>>>> +
>>>>> +/**
>>>>> + * cm3218x_acpi_get_cpm_info() - Get CPM object from ACPI
>>>>> + * @client pointer of struct i2c_client.
>>>>> + * @obj_name pointer of ACPI object name.
>>>>> + * @count maximum size of return array.
>>>>> + * @vals pointer of array for return elements.
>>>>> + *
>>>>> + * Convert ACPI CPM table to array. Special thanks Srinivas
>>> Pandruvada's
>>>>> + * help to implement this routine.
>>>>> + *
>>>>> + * Return: -ENODEV for fail.  Otherwise is number of elements.
>>>>> + */
>>>>> +static int cm3218x_acpi_get_cpm_info(struct i2c_client *client,
>>> char
>>>>> *obj_name,
>>>>> + int count, u64 *vals)
>>>>> +{
>>>>> + acpi_handle handle;
>>>>> + struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
>>>>> + int i;
>>>>> + acpi_status status;
>>>>> + union acpi_object *cpm = NULL;
>>>> no need to initialize cpm
>>>>
>>>>> +
>>>>> + handle = ACPI_HANDLE(&client->dev);
>>>>> + if (!handle)
>>>>> + return -ENODEV;
>>>>> +
>>>>> + status = acpi_evaluate_object(handle, obj_name, NULL, &buffer);
>>>>> + if (ACPI_FAILURE(status)) {
>>>>> + dev_err(&client->dev, "object %s not found\n", obj_name);
>>>>> + return -ENODEV;
>>>>> + }
>>>>> +
>>>>> + cpm = buffer.pointer;
>>>>> + for (i = 0; i < cpm->package.count && i < count; ++i) {
>>>>> + union acpi_object *elem;
>>>>> + elem = &(cpm->package.elements[i]);
>>>>> + vals[i] = elem->integer.value;
>>>>> + }
>>>>> +
>>>>> + kfree(buffer.pointer);
>>>>> +
>>>>> + return cpm->package.count;
>>>>> +}
>>>>> +
>>>>> +/**
>>>>> + * cm3218x_reg_init() - Initialize CM3218x registers
>>>>> + * @cm3218x: pointer of struct cm3218x.
>>>>> + *
>>>>> + * Initialize CM3218x ambient light sensor register to default
>>> values.
>>>>> + *
>>>>> +  Return: 0 for success; otherwise for error code.
>>>>> + */
>>>>> +static int cm3218x_reg_init(struct cm3218x_chip *chip)
>>>>> +{
>>>>> + struct i2c_client *client = chip->client;
>>>>> + int i;
>>>>> + s32 ret;
>>>>> + int cpm_elem_count;
>>>>> + u64 cpm_elems[20];
>>>>> + struct cmdev *cmdev;
>>>>> +
>>>>> + /* Default device */
>>>>> + chip->cmdev = &cm3218;
>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD] = CM3218x_CMD_DEFAULT;
>>>>> + chip->conf_regs[CM3218x_REG_ADDR_WH] = CM3218x_WH_DEFAULT;
>>>>> + chip->conf_regs[CM3218x_REG_ADDR_WL] = CM3218x_WL_DEFAULT;
>>>>> +
>>>>> + /* Disable interrupt */
>>>>> + cm3218x_interrupt_config(chip, 0);
>>>>> +
>>>>> + /* Disable Test Mode */
>>>>> + i2c_smbus_write_word_data(client, CM3218x_REG_ADDR_TEST,
>0x0000);
>>>>> +
>>>>> + /* Disable device */
>>>>> + i2c_smbus_write_word_data(client, CM3218x_REG_ADDR_CMD,
>>>>> + CM3218x_CMD_ALS_DISABLE);
>>>>> +
>>>>> + /* Identify device */
>>>>> + ret = i2c_smbus_read_word_data(client, CM3218x_REG_ADDR_ID);
>>>>> + if (ret < 0)
>>>>> + return ret;
>>>>> + switch (ret & 0xFF) {
>>>>> + case 0x18:
>>>>> + cmdev = chip->cmdev = &cm3218;
>>>>> + if (ret & 0x0800)
>>>>> + cmdev->int_type = INT_TYPE_I2C;
>>>>> + else
>>>>> + cmdev->int_type = INT_TYPE_SMBUS;
>>>>> + break;
>>>>> + case 0x81:
>>>>> + cmdev = chip->cmdev = &cm32181;
>>>>> + break;
>>>>> + case 0x82:
>>>>> + cmdev = chip->cmdev = &cm32182;
>>>>> + break;
>>>>> + default:
>>>>> + return -ENODEV;
>>>>> + }
>>>>> +
>>>>> + if (ACPI_HANDLE(&client->dev)) {
>>>>> + /* Load from ACPI */
>>>>> + cpm_elem_count = cm3218x_acpi_get_cpm_info(client, "CPM0",
>>>>> + ARRAY_SIZE(cpm_elems),
>>>>> + cpm_elems);
>>>>> + if (cpm_elem_count > 0) {
>>>>> + int header_num = 3;
>>>>> + int reg_num = cpm_elem_count - header_num;
>>>>> +
>>>>> + cmdev->regs_bmp = cpm_elems[2];
>>>>> + for (i = 0; i < reg_num; i++)
>>>>> + if (cmdev->regs_bmp & (1<<i))
>>>>> + chip->conf_regs[i] =
>>>>> + cpm_elems[header_num+i];
>>>>> + }
>>>>> +
>>>>> + cpm_elem_count = cm3218x_acpi_get_cpm_info(client, "CPM1",
>>>>> + ARRAY_SIZE(cpm_elems),
>>>>> + cpm_elems);
>>>>> + if (cpm_elem_count > 0) {
>>>>> + cmdev->mlux_per_bit = (int)cpm_elems[0] / 100;
>>>>> + cmdev->calibscale = (int)cpm_elems[1];
>>>>> + }
>>>>> + }
>>>>> +
>>>>> + /* Force to disable interrupt */
>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD] &=
>~CM3218x_CMD_ALS_INT_EN;
>>>>> +
>>>>> + /* Initialize registers*/
>>>> whitespace
>>>>
>>>>> + for (i = 0; i < CM3218x_CONF_REG_NUM; i++) {
>>>>> + if (cmdev->regs_bmp & (1<<i)) {
>>>>> + ret = i2c_smbus_write_word_data(client, i,
>>>>> + chip->conf_regs[i]);
>>>>> + if (ret < 0)
>>>>> + return ret;
>>>>> + }
>>>>> + }
>>>>> +
>>>>> + return 0;
>>>>> +}
>>>>> +
>>>>> +/**
>>>>> + *  cm3218x_read_als_it() - Get sensor integration time (ms)
>>>>> + *  @cm3218x: pointer of struct cm3218x
>>>>> + *  @val2: pointer of int to load the als_it value.
>>>>> + *
>>>>> + *  Report the current integartion time by millisecond.
>>>> integration time in milliseconds
>>>>
>>>>> + *
>>>>> + *  Return: IIO_VAL_INT_PLUS_MICRO for success, otherwise
>-EINVAL.
>>>>> + */
>>>>> +static int cm3218x_read_als_it(struct cm3218x_chip *chip, int
>>> *val2)
>>>>> +{
>>>>> + struct cmdev *cmdev = chip->cmdev;
>>>>> + u16 als_it;
>>>>> + int i;
>>>>> +
>>>>> + als_it = chip->conf_regs[CM3218x_REG_ADDR_CMD];
>>>>> + als_it &= CM3218x_CMD_ALS_IT_MASK;
>>>>> + als_it >>= CM3218x_CMD_ALS_IT_SHIFT;
>>>>> + for (i = 0; i < cmdev->num_als_it; i++) {
>>>>> + if (als_it == cmdev->als_it_bits[i]) {
>>>>> + *val2 = cmdev->als_it_values[i];
>>>>> + return IIO_VAL_INT_PLUS_MICRO;
>>>>> + }
>>>>> + }
>>>>> +
>>>>> + return -EINVAL;
>>>>> +}
>>>>> +
>>>>> +/**
>>>>> + * cm3218x_write_als_it() - Write sensor integration time
>>>>> + * @cm3218x: pointer of struct cm3218x.
>>>>> + * @val: integration time by millisecond.
>>>>> + *
>>>>> + * Convert integration time (ms) to sensor value.
>>>>> + *
>>>>> + * Return: i2c_smbus_write_word_data command return value.
>>>>> + */
>>>>> +static int cm3218x_write_als_it(struct cm3218x_chip *chip, int
>val)
>>>>> +{
>>>>> + struct i2c_client *client = chip->client;
>>>>> + struct cmdev *cmdev = chip->cmdev;
>>>>> + u16 als_it;
>>>>> + int ret, i;
>>>>> +
>>>>> + for (i = 0; i < cmdev->num_als_it; i++)
>>>>> + if (val <= cmdev->als_it_values[i])
>>>>> + break;
>>>>> + if (i >= cmdev->num_als_it)
>>>>> + i = cmdev->num_als_it - 1;
>>>>> +
>>>>> + als_it = cmdev->als_it_bits[i];
>>>>> + als_it <<= CM3218x_CMD_ALS_IT_SHIFT;
>>>>> +
>>>>> + mutex_lock(&chip->lock);
>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD] &=
>>>>> + ~CM3218x_CMD_ALS_IT_MASK;
>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD] |=
>>>>> + als_it;
>>>>> + ret = i2c_smbus_write_word_data(client, CM3218x_REG_ADDR_CMD,
>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD]);
>>>>> + mutex_unlock(&chip->lock);
>>>>> +
>>>>> + return ret;
>>>>> +}
>>>>> +
>>>>> +/**
>>>>> + * cm3218x_get_lux() - report current lux value
>>>>> + * @cm3218x: pointer of struct cm3218x.
>>>>> + *
>>>>> + * Convert sensor raw data to lux.  It depends on integration
>>>>> + * time and claibscale variable.
>>>> calibscale
>>>>
>>>>> + *
>>>>> + * Return: Positive value is lux, otherwise is error code.
>>>>> + */
>>>>> +static int cm3218x_get_lux(struct cm3218x_chip *chip)
>>>>> +{
>>>>> + struct i2c_client *client = chip->client;
>>>>> + struct cmdev *cmdev = chip->cmdev;
>>>>> + int ret;
>>>>> + int als_it;
>>>>> + int lux;
>>>> lux variable is not needed
>>>>
>>>>> + u64 tmp;
>>>>> +
>>>>> + /* Calculate mlux per bit based on als_it */
>>>>> + ret = cm3218x_read_als_it(chip, &als_it);
>>>>> + if (ret < 0)
>>>>> + return -EINVAL;
>>>>> + tmp = (__force u64)cmdev->mlux_per_bit;
>>>>> + tmp *= cmdev->mlux_per_bit_base_it;
>>>>> + tmp = div_u64(tmp, als_it);
>>>>> +
>>>>> + /* Get als_raw */
>>>>> + if (!(chip->conf_regs[CM3218x_REG_ADDR_CMD] &
>>> CM3218x_CMD_ALS_INT_EN))
>>>>> + chip->als_raw = i2c_smbus_read_word_data(
>>>>> + client,
>>>>> + CM3218x_REG_ADDR_ALS);
>>>>> + if (chip->als_raw < 0)
>>>>> + return chip->als_raw;
>>>>> +
>>>>> + tmp *= chip->als_raw;
>>>>> + tmp *= cmdev->calibscale;
>>>>> + tmp = div_u64(tmp, CM3218x_CALIBSCALE_RESOLUTION);
>>>>> + tmp = div_u64(tmp, MLUX_PER_LUX);
>>>>> +
>>>>> + if (tmp > 0xFFFF)
>>>>> + tmp = 0xFFFF;
>>>>> +
>>>>> + lux = (int)tmp;
>>>>> + return lux;
>>>>> +}
>>>>> +
>>>>> +static int cm3218x_read_raw(struct iio_dev *indio_dev,
>>>>> + struct iio_chan_spec const *chan,
>>>>> + int *val, int *val2, long mask)
>>>>> +{
>>>>> + struct cm3218x_chip *chip = iio_priv(indio_dev);
>>>>> + struct cmdev *cmdev = chip->cmdev;
>>>>> + int ret;
>>>>> +
>>>>> + switch (mask) {
>>>>> + case IIO_CHAN_INFO_PROCESSED:
>>>>> + ret = cm3218x_get_lux(chip);
>>>>> + if (ret < 0)
>>>>> + return ret;
>>>>> + *val = ret;
>>>>> + return IIO_VAL_INT;
>>>>> + case IIO_CHAN_INFO_CALIBSCALE:
>>>>> + *val = cmdev->calibscale;
>>>>> + return IIO_VAL_INT;
>>>>> + case IIO_CHAN_INFO_INT_TIME:
>>>>> + *val = 0;
>>>>> + ret = cm3218x_read_als_it(chip, val2);
>>>>> + return ret;
>>>>> + }
>>>>> +
>>>>> + return -EINVAL;
>>>>> +}
>>>>> +
>>>>> +static int cm3218x_write_raw(struct iio_dev *indio_dev,
>>>>> + struct iio_chan_spec const *chan,
>>>>> + int val, int val2, long mask)
>>>>> +{
>>>>> + struct cm3218x_chip *chip = iio_priv(indio_dev);
>>>>> + struct cmdev *cmdev = chip->cmdev;
>>>>> + int ret;
>>>> ret not needed
>>>>
>>>>> +
>>>>> + switch (mask) {
>>>>> + case IIO_CHAN_INFO_CALIBSCALE:
>>>>> + cmdev->calibscale = val;
>>>>> + return val;
>>>>> + case IIO_CHAN_INFO_INT_TIME:
>>>> val==0 could be checked here
>>>>
>>>>> + ret = cm3218x_write_als_it(chip, val2);
>>>>> + return ret;
>>>>> + }
>>>>> +
>>>>> + return -EINVAL;
>>>>> +}
>>>>> +
>>>>> +/**
>>>>> + * cm3218x_get_it_available() - Get available ALS IT value
>>>>> + * @dev: pointer of struct device.
>>>>> + * @attr: pointer of struct device_attribute.
>>>>> + * @buf: pointer of return string buffer.
>>>>> + *
>>>>> + * Display the available integration time values by millisecond.
>>>>> + *
>>>>> + * Return: string length.
>>>>> + */
>>>>> +static ssize_t cm3218x_get_it_available(struct device *dev,
>>>>> + struct device_attribute *attr, char *buf)
>>>>> +{
>>>>> + struct cm3218x_chip *chip = iio_priv(dev_to_iio_dev(dev));
>>>>> + struct cmdev *cmdev = chip->cmdev;
>>>>> + int i, len;
>>>>> +
>>>>> + for (i = 0, len = 0; i < cmdev->num_als_it; i++)
>>>>> + len += sprintf(buf + len, "0.%06u ", cmdev->als_it_values[i]);
>>>> scnprintf(buf+len, PAGESIZE-len, ...) could be used
>>>>
>>>>> + return len + sprintf(buf + len, "\n");
>>>>> +}
>>>>> +
>>>>> +/**
>>>>> + * cm3218x_threshold_update() - Update the threshold registers.
>>>>> + * @dev: pointer of struct cm3218x_chip.
>>>> @chip
>>>>
>>>>> + * @percent: +/- percent.
>>>>> + *
>>>>> + * Based on the current ALS value, tupdate the hi and low
>threshold
>>>>> registers.
>>>>> + *
>>>>> + * Return: string length.
>>>> definitely not the string length
>>>>
>>>>> + */
>>>>> +static int cm3218x_threshold_update(struct cm3218x_chip *chip,
>int
>>>>> percent)
>>>>> +{
>>>>> + struct i2c_client *client = chip->client;
>>>>> + int ret;
>>>>> + int wh, wl;
>>>>> +
>>>>> + ret = chip->als_raw = i2c_smbus_read_word_data(client,
>>>>> + CM3218x_REG_ADDR_ALS);
>>>>> + if (ret < 0)
>>>>> + return ret;
>>>>> +
>>>>> + wh = wl = ret;
>>>>> + ret *= percent;
>>>>> + ret /= 100;
>>>>> + if (ret < 1)
>>>>> + ret = 1;
>>>>> + wh += ret;
>>>>> + wl -= ret;
>>>>> + if (wh > 65535)
>>>>> + wh = 65535;
>>>>> + if (wl < 0)
>>>>> + wl = 0;
>>>>> +
>>>>> + chip->conf_regs[CM3218x_REG_ADDR_WH] = wh;
>>>>> + ret = i2c_smbus_write_word_data(
>>>>> + client,
>>>>> + CM3218x_REG_ADDR_WH,
>>>>> + chip->conf_regs[CM3218x_REG_ADDR_WH]);
>>>>> + if (ret < 0)
>>>>> + return ret;
>>>>> +
>>>>> + chip->conf_regs[CM3218x_REG_ADDR_WL] = wl;
>>>>> + ret = i2c_smbus_write_word_data(
>>>>> + client,
>>>>> + CM3218x_REG_ADDR_WL,
>>>>> + chip->conf_regs[CM3218x_REG_ADDR_WL]);
>>>> just
>>>> return ret;
>>>>
>>>>> + if (ret < 0)
>>>>> + return ret;
>>>>> +
>>>>> + return 0;
>>>>> +}
>>>>> +
>>>>> +/**
>>>>> + * cm3218x_event_handler() - Interrupt handling routine.
>>>>> + * @irq: irq number.
>>>>> + * @private: pointer of void.
>>>>> + *
>>>>> + * Clean interrupt and reset threshold registers.
>>>>> + *
>>>>> + * Return: string length.
>>>>
>>>>
>>>>> + */
>>>>> +static irqreturn_t cm3218x_event_handler(int irq, void *private)
>>>>> +{
>>>>> + struct iio_dev *dev_info = private;
>>>>> + struct cm3218x_chip *chip = iio_priv(dev_info);
>>>>> + int ret;
>>>>> +
>>>>> + mutex_lock(&chip->lock);
>>>>> +
>>>>> + /* Disable interrupt */
>>>>> + ret = cm3218x_interrupt_config(chip, 0);
>>>>> + if (ret < 0)
>>>>> + goto error_handler_unlock;
>>>>> +
>>>>> + /* Update Hi/Lo windows */
>>>>> + ret = cm3218x_threshold_update(chip, CM3218x_THRESHOLD_PERCENT);
>>>>> + if (ret < 0)
>>>>> + goto error_handler_unlock;
>>>>> +
>>>>> + /* Enable interrupt */
>>>>> + ret = cm3218x_interrupt_config(chip, 1);
>>>>> + if (ret < 0)
>>>>> + goto error_handler_unlock;
>>>>> +
>>>>> + mutex_unlock(&chip->lock);
>>>>> +
>>>>> + return IRQ_HANDLED;
>>>>> +
>>>>> +error_handler_unlock:
>>>>> + mutex_unlock(&chip->lock);
>>>>> + return IRQ_NONE;
>>>> I think it should be IRQ_HANDLED always
>>>> there is no check if the interrupt indeed stems from this device
>>>>
>>>>> +}
>>>>> +
>>>>> +static const struct iio_chan_spec cm3218x_channels[] = {
>>>>> + {
>>>>> + .type = IIO_LIGHT,
>>>>> + .info_mask_separate =
>>>>> + BIT(IIO_CHAN_INFO_PROCESSED) |
>>>>> + BIT(IIO_CHAN_INFO_CALIBSCALE) |
>>>>> + BIT(IIO_CHAN_INFO_INT_TIME),
>>>>> + }
>>>>> +};
>>>>> +
>>>>> +static IIO_DEVICE_ATTR(in_illuminance_integration_time_available,
>>>>> + S_IRUGO, cm3218x_get_it_available, NULL, 0);
>>>>> +
>>>>> +static struct attribute *cm3218x_attributes[] = {
>>>>> +
>>>
>&iio_dev_attr_in_illuminance_integration_time_available.dev_attr.attr,
>>>>> + NULL,
>>>>> +};
>>>>> +
>>>>> +static const struct attribute_group cm3218x_attribute_group = {
>>>>> + .attrs = cm3218x_attributes
>>>>> +};
>>>>> +
>>>>> +static const struct iio_info cm3218x_info = {
>>>>> + .driver_module = THIS_MODULE,
>>>>> + .read_raw = &cm3218x_read_raw,
>>>>> + .write_raw = &cm3218x_write_raw,
>>>>> + .attrs = &cm3218x_attribute_group,
>>>>> +};
>>>>> +
>>>>> +static int cm3218x_probe(struct i2c_client *client,
>>>>> + const struct i2c_device_id *id)
>>>>> +{
>>>>> + struct cm3218x_chip *chip;
>>>>> + struct iio_dev *indio_dev;
>>>>> + int ret;
>>>>> +
>>>>> + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
>>>>> + if (!indio_dev) {
>>>>> + dev_err(&client->dev, "devm_iio_device_alloc failed\n");
>>>>> + return -ENOMEM;
>>>>> + }
>>>>> +
>>>>> + chip = iio_priv(indio_dev);
>>>>> + i2c_set_clientdata(client, indio_dev);
>>>>> + chip->client = client;
>>>>> +
>>>>> + mutex_init(&chip->lock);
>>>>> + indio_dev->dev.parent = &client->dev;
>>>>> + indio_dev->channels = cm3218x_channels;
>>>>> + indio_dev->num_channels = ARRAY_SIZE(cm3218x_channels);
>>>>> + indio_dev->info = &cm3218x_info;
>>>>> + if (id && id->name)
>>>>> + indio_dev->name = id->name;
>>>>> + else
>>>>> + indio_dev->name = (char *)dev_name(&client->dev);
>>>>> + indio_dev->modes = INDIO_DIRECT_MODE;
>>>>> +
>>>>> + ret = cm3218x_reg_init(chip);
>>>>> + if (ret) {
>>>>> + dev_err(&client->dev,
>>>>> + "%s: register init failed\n",
>>>>> + __func__);
>>>>> + return ret;
>>>>> + }
>>>>> +
>>>>> + if (client->irq) {
>>>>> + ret = request_threaded_irq(client->irq,
>>>>> + NULL,
>>>>> + cm3218x_event_handler,
>>>>> + IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
>>>>> + "cm3218x_event",
>>>>> + indio_dev);
>>>>> +
>>>>> + if (ret < 0) {
>>>>> + dev_err(&client->dev, "irq request error %d\n",
>>>>> + -ret);
>>>>> + goto error_disable_int;
>>>>> + }
>>>>> + }
>>>>> +
>>>>> + ret = iio_device_register(indio_dev);
>>>>> + if (ret < 0) {
>>>>> + dev_err(&client->dev,
>>>>> + "%s: regist device failed\n",
>>>>> + __func__);
>>>>> + goto error_free_irq;
>>>>> + }
>>>>> +
>>>>> + if (client->irq) {
>>>>> + ret = cm3218x_threshold_update(chip, CM3218x_THRESHOLD_PERCENT);
>>>>> + if (ret < 0)
>>>>> + goto error_free_irq;
>>>>> +
>>>>> + ret = cm3218x_interrupt_config(chip, 1);
>>>>> + if (ret < 0)
>>>>> + goto error_free_irq;
>>>>> + }
>>>>> +
>>>>> + return 0;
>>>>> +
>>>>> +error_free_irq:
>>>>> + free_irq(client->irq, indio_dev);
>>>>> +error_disable_int:
>>>>> + cm3218x_interrupt_config(chip, 0);
>>>>> + return ret;
>>>>> +}
>>>>> +
>>>>> +static int cm3218x_remove(struct i2c_client *client)
>>>>> +{
>>>>> + struct iio_dev *indio_dev = i2c_get_clientdata(client);
>>>>> + struct cm3218x_chip *chip = iio_priv(indio_dev);
>>>>> +
>>>>> + cm3218x_interrupt_config(chip, 0);
>>>>> + if (client->irq)
>>>>> + free_irq(client->irq, indio_dev);
>>>>> + iio_device_unregister(indio_dev);
>>>>> + return 0;
>>>>> +}
>>>>> +
>>>>> +static const struct i2c_device_id cm3218x_id[] = {
>>>>> + { "cm3218x", 0},
>>>>> + { }
>>>>> +};
>>>>> +
>>>>> +MODULE_DEVICE_TABLE(i2c, cm3218x_id);
>>>>> +
>>>>> +static const struct of_device_id cm3218x_of_match[] = {
>>>>> + { .compatible = "capella,cm3218x" },
>>>>> + { }
>>>>> +};
>>>>> +
>>>>> +static const struct acpi_device_id cm3218x_acpi_match[] = {
>>>>> + { "CPLM3218", 0},
>>>>> + {},
>>>>> +};
>>>>> +
>>>>> +MODULE_DEVICE_TABLE(acpi, cm3218x_acpi_match);
>>>>> +
>>>>> +static struct i2c_driver cm3218x_driver = {
>>>>> + .driver = {
>>>>> + .name = "cm3218x",
>>>>> + .acpi_match_table = ACPI_PTR(cm3218x_acpi_match),
>>>>> + .of_match_table = of_match_ptr(cm3218x_of_match),
>>>>> + .owner = THIS_MODULE,
>>>>> + },
>>>>> + .id_table = cm3218x_id,
>>>>> + .probe = cm3218x_probe,
>>>>> + .remove = cm3218x_remove,
>>>>> +};
>>>>> +
>>>>> +module_i2c_driver(cm3218x_driver);
>>>>> +
>>>>> +MODULE_AUTHOR("Kevin Tsai <ktsai-GubuWUlQtMwciDkP5Hr2oA@public.gmane.org>");
>>>>> +MODULE_DESCRIPTION("CM3218x ambient light sensor driver");
>>>>> +MODULE_LICENSE("GPL");
>>>>>
>>>> -- 
>>>>
>>>> Peter Meerwald
>>>> +43-664-2444418 (mobile)

-- 
Sent from my Android phone with K-9 Mail. Please excuse my brevity.

Re: [PATCH V1 1/1] iio: add Capella cm3218x ambient light sensor driver.

[Srinivas Pandruvada]

On 03/21/2014 03:05 PM, Jonathan Cameron wrote:
>
> On March 20, 2014 11:19:49 PM GMT+00:00, Srinivas Pandruvada <srinivas.pandruvada-VuQAYsv1563Yd54FQh9/CA@public.gmane.org> wrote:
>> On 03/19/2014 11:54 PM, Jonathan Cameron wrote:
>>> On March 20, 2014 12:58:02 AM GMT+00:00, Kevin Tsai
>> <ktsai-GubuWUlQtMwciDkP5Hr2oA@public.gmane.org> wrote:
>>>> Hi Peter,
>>>>
>>>> Thanks for your advise.  I'll update my code.
>>>>
>>>> ACPI is optional.  Most PC manufactory may store the lens factor to
>>>> ACPI
>>>> table.  But, phone customers like to modify the parameters inside
>> code.
>>>> CM3218 have two versions.  The old version need to read SMBus ARA
>>>> register
>>>> to clean interrupt.  That's why I need to change I2C chip address.
>>>> Please
>>>> guid me if you have a better way to access two addresses.
>>> Would the smbus alert infrastructure in drivers/i2ç/i2c-smbus.c help?
>> The smbus alert notification are based on the underlying i2c
>> controller.
>> Not every controller supports. I can see only one controller driver in
>> the upstream Linux added this support.
> To my mind adding wider support for the alert functionality will be the way forward.
>
> Wolfram, any idea why so few bus drivers implement the smbus alert stuff? I would
>   guess you won't be against wider support of this using existing infrastructure?
SMALRT is a physical pin connection. Most of the i2C controlleron X86 
will have no option to connect
SMALRT signal. So may be we need a common API to read instead, to read 
and get status.

Thanks,
Srinivas

>> Thanks,
>> Srinivas
>>
>>>> Thanks.
>>>>
>>>> Kevin Tsai
>>>> 03/19/14
>>>>
>>>> ----- Original Message -----
>>>> From: "Peter Meerwald" <pmeerw-jW+XmwGofnusTnJN9+BGXg@public.gmane.org>
>>>> To: "Kevin Tsai" <ktsai-GubuWUlQtMwciDkP5Hr2oA@public.gmane.org>
>>>> Cc: "Jonathan Cameron" <jic23-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>;
>> <linux-iio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
>>>> Sent: Wednesday, March 19, 2014 11:07
>>>> Subject: Re: [PATCH V1 1/1] iio: add Capella cm3218x ambient light
>>>> sensor
>>>> driver.
>>>>
>>>>
>>>>>> Add Capella Microsystem CM3218x family Ambient Light Sensor IIO
>>>> driver.
>>>>>> This driver will convert raw data to lux value.  Default
>> parameters
>>>> are
>>>>>> for reference only.  It will detect ACPI table to load per-system
>>>>>> manufacturing
>>>>>> parameters.
>>>>> nitpicking below
>>>>>
>>>>>> ---
>>>>>>    .../devicetree/bindings/i2c/trivial-devices.txt    |   1 +
>>>>>>    drivers/iio/light/Kconfig                          |  11 +
>>>>>>    drivers/iio/light/Makefile                         |   1 +
>>>>>>    drivers/iio/light/cm3218x.c                        | 769
>>>>>> +++++++++++++++++++++
>>>>>>    4 files changed, 782 insertions(+)
>>>>>>    create mode 100644 drivers/iio/light/cm3218x.c
>>>>>>
>>>>>> diff --git
>>>> a/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>>>>>> b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>>>>>> index 1a1ac2e..29e7eae 100644
>>>>>> --- a/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>>>>>> +++ b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>>>>>> @@ -17,6 +17,7 @@ at,24c08 i2c serial eeprom  (24cxx)
>>>>>>    atmel,24c02 i2c serial eeprom  (24cxx)
>>>>>>    atmel,at97sc3204t i2c trusted platform module (TPM)
>>>>>>    capella,cm32181 CM32181: Ambient Light Sensor
>>>>>> +capella,cm3218x CM3218x: Ambient Light Sensor
>>>>>>    catalyst,24c32 i2c serial eeprom
>>>>>>    dallas,ds1307 64 x 8, Serial, I2C Real-Time Clock
>>>>>>    dallas,ds1338 I2C RTC with 56-Byte NV RAM
>>>>>> diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
>>>>>> index d12b2a0..45a22a6 100644
>>>>>> --- a/drivers/iio/light/Kconfig
>>>>>> +++ b/drivers/iio/light/Kconfig
>>>>>> @@ -38,6 +38,17 @@ config CM32181
>>>>>>    To compile this driver as a module, choose M here:
>>>>>>    the module will be called cm32181.
>>>>>>
>>>>>> +config CM3218X
>>>>>> + depends on I2C
>>>>> is there an ACPI dependency?
>>>>>
>>>>>> + tristate "CM3218x driver"
>>>>>> + help
>>>>>> + Say Y here if you use cm3218x.
>>>>>> + This option enables ambient light sensor using
>>>>>> + Capella cm3218x device driver.
>>>>>> +
>>>>>> + To compile this driver as a module, choose M here:
>>>>>> + the module will be called cm3218x.
>>>>>> +
>>>>>>    config CM36651
>>>>>>    depends on I2C
>>>>>>    tristate "CM36651 driver"
>>>>>> diff --git a/drivers/iio/light/Makefile
>> b/drivers/iio/light/Makefile
>>>>>> index 60e35ac..a506c23 100644
>>>>>> --- a/drivers/iio/light/Makefile
>>>>>> +++ b/drivers/iio/light/Makefile
>>>>>> @@ -6,6 +6,7 @@
>>>>>>    obj-$(CONFIG_ADJD_S311) += adjd_s311.o
>>>>>>    obj-$(CONFIG_APDS9300) += apds9300.o
>>>>>>    obj-$(CONFIG_CM32181) += cm32181.o
>>>>>> +obj-$(CONFIG_CM3218X) += cm3218x.o
>>>>>>    obj-$(CONFIG_CM36651) += cm36651.o
>>>>>>    obj-$(CONFIG_GP2AP020A00F) += gp2ap020a00f.o
>>>>>>    obj-$(CONFIG_HID_SENSOR_ALS) += hid-sensor-als.o
>>>>>> diff --git a/drivers/iio/light/cm3218x.c
>>>> b/drivers/iio/light/cm3218x.c
>>>>>> new file mode 100644
>>>>>> index 0000000..e422f68
>>>>>> --- /dev/null
>>>>>> +++ b/drivers/iio/light/cm3218x.c
>>>>>> @@ -0,0 +1,769 @@
>>>>>> +/*
>>>>>> + * Copyright (C) 2014 Capella Microsystems Inc.
>>>>>> + * Author: Kevin Tsai <ktsai-GubuWUlQtMwciDkP5Hr2oA@public.gmane.org>
>>>>>> + *
>>>>>> + * This program is free software; you can redistribute it and/or
>>>> modify
>>>>>> it
>>>>>> + * under the terms of the GNU General Public License version 2,
>> as
>>>>>> published
>>>>>> + * by the Free Software Foundation.
>>>>>> + *
>>>>>> + * Special thanks Srinivas Pandruvada
>>>>>> <srinivas.pandruvada-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
>>>>>> + * help to add ACPI support.
>>>>>> + *
>>>>>> + */
>>>>>> +
>>>>>> +#include <linux/delay.h>
>>>>>> +#include <linux/err.h>
>>>>>> +#include <linux/i2c.h>
>>>>>> +#include <linux/mutex.h>
>>>>>> +#include <linux/module.h>
>>>>>> +#include <linux/interrupt.h>
>>>>>> +#include <linux/regulator/consumer.h>
>>>>>> +#include <linux/iio/iio.h>
>>>>>> +#include <linux/iio/sysfs.h>
>>>>>> +#include <linux/iio/events.h>
>>>>>> +#include <linux/init.h>
>>>>>> +#include <linux/acpi.h>
>>>>>> +
>>>>>> +/* Registers Address */
>>>>>> +#define CM3218x_REG_ADDR_CMD 0x00
>>>>>> +#define CM3218x_REG_ADDR_WH 0x01
>>>>>> +#define CM3218x_REG_ADDR_WL 0x02
>>>>>> +#define CM3218x_REG_ADDR_TEST 0x03
>>>>> inconsistent whitespace allover
>>>>>
>>>>>> +#define CM3218x_REG_ADDR_ALS 0x04
>>>>>> +#define CM3218x_REG_ADDR_STATUS 0x06
>>>>>> +#define CM3218x_REG_ADDR_ID 0x07
>>>>>> +
>>>>>> +/* Number of Configurable Registers */
>>>>>> +#define CM3218x_CONF_REG_NUM 16
>>>>>> +
>>>>>> +/* CMD register */
>>>>>> +#define CM3218x_CMD_ALS_DISABLE 0x01
>>>>>> +#define CM3218x_CMD_ALS_INT_EN 0x02
>>>>>> +#define CM3218x_CMD_ALS_THRES_WINDOW 0x04
>>>>>> +
>>>>>> +#define CM3218x_CMD_ALS_PERS_SHIFT 4
>>>>>> +#define CM3218x_CMD_ALS_PERS_MASK (0x03 <<
>>>> CM3218x_CMD_ALS_PERS_SHIFT)
>>>>>> +#define CM3218x_CMD_ALS_PERS_DEFAULT (0x01 <<
>>>>>> CM3218x_CMD_ALS_PERS_SHIFT)
>>>>>> +
>>>>>> +#define CM3218x_CMD_ALS_IT_SHIFT 6
>>>>>> +#define CM3218x_CMD_ALS_IT_MASK (0x0F <<
>> CM3218x_CMD_ALS_IT_SHIFT)
>>>>>> +#define CM3218x_CMD_ALS_IT_DEFAULT (0x01 <<
>>>> CM3218x_CMD_ALS_IT_SHIFT)
>>>>>> +
>>>>>> +#define CM3218x_CMD_ALS_HS_SHIFT 11
>>>>>> +#define CM3218x_CMD_ALS_HS_MASK (0x01 <<
>> CM3218x_CMD_ALS_HS_SHIFT)
>>>>>> +#define CM3218x_CMD_ALS_HS_DEFAULT (0x00 <<
>>>> CM3218x_CMD_ALS_HS_SHIFT)
>>>>>> +
>>>>>> +#define CM3218x_CMD_DEFAULT (CM3218x_CMD_ALS_THRES_WINDOW |\
>>>>>> + CM3218x_CMD_ALS_PERS_DEFAULT |\
>>>>>> + CM3218x_CMD_ALS_IT_DEFAULT |\
>>>>>> + CM3218x_CMD_ALS_HS_DEFAULT)
>>>>>> +
>>>>>> +#define CM3218x_WH_DEFAULT 0xFFFF
>>>>>> +#define CM3218x_WL_DEFAULT 0x0000
>>>>>> +
>>>>>> +#define CM3218x_CALIBSCALE_DEFAULT 100000
>>>>>> +#define CM3218x_CALIBSCALE_RESOLUTION 100000
>>>>>> +#define MLUX_PER_LUX 1000
>>>>> CM3218x prefix missing
>>>>>
>>>>> the lowercase x in macros is a bit weird for my taste
>>>>>
>>>>>> +#define CM3218x_THRESHOLD_PERCENT 10 /* 10 percent */
>>>>>> +
>>>>>> +/* CM3218 Family */
>>>>>> +#define CM3218_MLUX_PER_BIT_DEFAULT 5 /* Depend on system */
>>>>>> +#define CM3218_MLUX_PER_BIT_BASE_IT 800000
>>>>>> +static int CM3218_als_it_bits[] = {0, 1, 2, 3};
>>>>>> +static int CM3218_als_it_values[] = {100000, 200000, 400000,
>>>> 800000};
>>>>> const missing
>>>>>
>>>>>> +
>>>>>> +/* CM32181 Family */
>>>>>> +#define CM32181_MLUX_PER_BIT_DEFAULT 5
>>>>>> +#define CM32181_MLUX_PER_BIT_BASE_IT 800000
>>>>>> +static int CM32181_als_it_bits[] = {12, 8, 0, 1, 2, 3};
>>>>>> +static int CM32181_als_it_values[] = {
>>>>>> + 25000, 50000, 100000, 200000, 400000, 800000};
>>>>> const missing
>>>>>
>>>>>> +
>>>>>> +/* CM32182 Family */
>>>>>> +#define CM32182_MLUX_PER_BIT_DEFAULT 5
>>>>>> +#define CM32182_MLUX_PER_BIT_BASE_IT 800000
>>>>>> +static int CM32182_als_it_bits[] = {12, 8, 0, 1, 2, 3};
>>>>>> +static int CM32182_als_it_values[] = {
>>>>>> + 25000, 50000, 100000, 200000, 400000, 800000};
>>>>> const missing
>>>>>
>>>>> these definitions are largely identical and could be dropped; they
>>>> are
>>>>> only used to fill device-specific tables below; why have a separate
>>>>> define here?
>>>>>
>>>>>> +
>>>>>> +struct cmdev {
>>>>> prefix?
>>>>>
>>>>>> + u32 family_id;
>>>>>> + int int_type;
>>>>>> +#define INT_TYPE_SMBUS 0
>>>>>> +#define INT_TYPE_I2C 1
>>>>> prefix?
>>>>>
>>>>>> + int regs_bmp;
>>>>>> + int calibscale;
>>>>>> + int mlux_per_bit;
>>>>>> + int mlux_per_bit_base_it;
>>>>>> + int *als_it_bits;
>>>>>> + int *als_it_values;
>>>>>> + int num_als_it;
>>>>>> +};
>>>>>> +
>>>>>> +static struct cmdev cm3218 = {
>>>>>> + 3218, INT_TYPE_SMBUS, 0x0F, CM3218x_CALIBSCALE_DEFAULT,
>>>>>> + CM3218_MLUX_PER_BIT_DEFAULT, CM3218_MLUX_PER_BIT_BASE_IT,
>>>>>> + CM3218_als_it_bits, CM3218_als_it_values,
>>>>>> + ARRAY_SIZE(CM3218_als_it_bits)};
>>>>>> +
>>>>>> +static struct cmdev cm32181 = {
>>>>>> + 32181, INT_TYPE_I2C, 0x0F, CM3218x_CALIBSCALE_DEFAULT,
>>>>>> + CM32181_MLUX_PER_BIT_DEFAULT, CM32181_MLUX_PER_BIT_BASE_IT,
>>>>>> + CM32181_als_it_bits, CM32181_als_it_values,
>>>>>> + ARRAY_SIZE(CM32181_als_it_bits)};
>>>>>> +
>>>>>> +static struct cmdev cm32182 = {
>>>>>> + 32182, INT_TYPE_I2C, 0x0F, CM3218x_CALIBSCALE_DEFAULT,
>>>>>> + CM32182_MLUX_PER_BIT_DEFAULT, CM32182_MLUX_PER_BIT_BASE_IT,
>>>>>> + CM32182_als_it_bits, CM32182_als_it_values,
>>>>>> + ARRAY_SIZE(CM32182_als_it_bits)};
>>>>>> +
>>>>>> +struct cm3218x_chip {
>>>>>> + struct i2c_client *client;
>>>>>> + struct cmdev *cmdev;
>>>>>> + struct mutex lock;
>>>>>> + u16 conf_regs[CM3218x_CONF_REG_NUM];
>>>>>> + int als_raw;
>>>>>> +};
>>>>>> +
>>>>>> +static int cm3218x_get_lux(struct cm3218x_chip *chip);
>>>>>> +static int cm3218x_threshold_update(struct cm3218x_chip *chip,
>> int
>>>>>> percent);
>>>>>> +static int cm3218x_read_als_it(struct cm3218x_chip *chip, int
>>>> *val2);
>>>>>> +
>>>>>> +/**
>>>>>> + * cm3218x_read_ara() - Read ARA register
>>>>>> + * @cm3218x: pointer of struct cm3218x.
>>>>> @chip
>>>>>
>>>>>> + *
>>>>>> + * Following SMBus protocol, ARA register is available only when
>>>>>> interrupt
>>>>>> + * event happened.  Read it to clean interrupt event.  Otherwise,
>>>> other
>>>>>> + * device address/registers will be blocked during interrupt
>> event.
>>>>>> + *
>>>>>> + * Return: 0 for success; otherwise for error code.
>>>>>> + */
>>>>>> +static int cm3218x_read_ara(struct cm3218x_chip *chip)
>>>>>> +{
>>>>>> + struct i2c_client *client = chip->client;
>>>>>> + int status;
>>>>>> + unsigned short addr;
>>>>>> +
>>>>> this looks dangerous: temporarily changing the I2C chip address!
>>>>>
>>>>>> + addr = client->addr;
>>>>>> + client->addr = 0x0C;
>>>>>> + status = i2c_smbus_read_byte(client);
>>>>>> + client->addr = addr;
>>>>>> +
>>>>>> + if (status < 0)
>>>>>> + return -ENODEV;
>>>>>> +
>>>>>> + return status;
>>>>>> +}
>>>>>> +
>>>>>> +/**
>>>>>> + * cm3218x_interrupt_config() - Enable/Disable CM3218x interrupt
>>>>>> + * @cm3218x: pointer of struct cm3218x.
>>>>> @chip: pointer to struct cm3218x_chip
>>>>>
>>>>>> + * @enable: 0 to disable; otherwise to enable
>>>>>> + *
>>>>>> + * Config CM3218x interrupt control bit.
>>>>>> + *
>>>>>> + * Return: 0 for success; otherwise for error code.
>>>>>> + */
>>>>>> +static int cm3218x_interrupt_config(struct cm3218x_chip *chip,
>> int
>>>>>> enable)
>>>>>> +{
>>>>>> + struct i2c_client *client = chip->client;
>>>>>> + struct cmdev *cmdev = chip->cmdev;
>>>>>> + int status;
>>>>>> +
>>>>>> + if (!cmdev)
>>>>>> + return -ENODEV;
>>>>>> +
>>>>>> + /* Force to clean interrupt */
>>>>>> + if (cmdev->int_type == INT_TYPE_I2C) {
>>>>>> + status = i2c_smbus_read_word_data(client,
>>>>>> + CM3218x_REG_ADDR_STATUS);
>>>>>> + if (status < 0)
>>>>>> + cmdev->int_type = INT_TYPE_SMBUS;
>>>>>> + }
>>>>>> + if (cmdev->int_type == INT_TYPE_SMBUS)
>>>>>> + cm3218x_read_ara(chip);
>>>>>> +
>>>>>> + if (enable)
>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD] |=
>>>>>> + CM3218x_CMD_ALS_INT_EN;
>>>>>> + else
>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD] &=
>>>>>> + ~CM3218x_CMD_ALS_INT_EN;
>>>>>> +
>>>>>> + status = i2c_smbus_write_word_data(client, CM3218x_REG_ADDR_CMD,
>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD]);
>>>>>> +
>>>>>> + if (status < 0)
>>>>>> + return -ENODEV;
>>>>>> +
>>>>>> + return status;
>>>>>> +}
>>>>>> +
>>>>>> +/**
>>>>>> + * cm3218x_acpi_get_cpm_info() - Get CPM object from ACPI
>>>>>> + * @client pointer of struct i2c_client.
>>>>>> + * @obj_name pointer of ACPI object name.
>>>>>> + * @count maximum size of return array.
>>>>>> + * @vals pointer of array for return elements.
>>>>>> + *
>>>>>> + * Convert ACPI CPM table to array. Special thanks Srinivas
>>>> Pandruvada's
>>>>>> + * help to implement this routine.
>>>>>> + *
>>>>>> + * Return: -ENODEV for fail.  Otherwise is number of elements.
>>>>>> + */
>>>>>> +static int cm3218x_acpi_get_cpm_info(struct i2c_client *client,
>>>> char
>>>>>> *obj_name,
>>>>>> + int count, u64 *vals)
>>>>>> +{
>>>>>> + acpi_handle handle;
>>>>>> + struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
>>>>>> + int i;
>>>>>> + acpi_status status;
>>>>>> + union acpi_object *cpm = NULL;
>>>>> no need to initialize cpm
>>>>>
>>>>>> +
>>>>>> + handle = ACPI_HANDLE(&client->dev);
>>>>>> + if (!handle)
>>>>>> + return -ENODEV;
>>>>>> +
>>>>>> + status = acpi_evaluate_object(handle, obj_name, NULL, &buffer);
>>>>>> + if (ACPI_FAILURE(status)) {
>>>>>> + dev_err(&client->dev, "object %s not found\n", obj_name);
>>>>>> + return -ENODEV;
>>>>>> + }
>>>>>> +
>>>>>> + cpm = buffer.pointer;
>>>>>> + for (i = 0; i < cpm->package.count && i < count; ++i) {
>>>>>> + union acpi_object *elem;
>>>>>> + elem = &(cpm->package.elements[i]);
>>>>>> + vals[i] = elem->integer.value;
>>>>>> + }
>>>>>> +
>>>>>> + kfree(buffer.pointer);
>>>>>> +
>>>>>> + return cpm->package.count;
>>>>>> +}
>>>>>> +
>>>>>> +/**
>>>>>> + * cm3218x_reg_init() - Initialize CM3218x registers
>>>>>> + * @cm3218x: pointer of struct cm3218x.
>>>>>> + *
>>>>>> + * Initialize CM3218x ambient light sensor register to default
>>>> values.
>>>>>> + *
>>>>>> +  Return: 0 for success; otherwise for error code.
>>>>>> + */
>>>>>> +static int cm3218x_reg_init(struct cm3218x_chip *chip)
>>>>>> +{
>>>>>> + struct i2c_client *client = chip->client;
>>>>>> + int i;
>>>>>> + s32 ret;
>>>>>> + int cpm_elem_count;
>>>>>> + u64 cpm_elems[20];
>>>>>> + struct cmdev *cmdev;
>>>>>> +
>>>>>> + /* Default device */
>>>>>> + chip->cmdev = &cm3218;
>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD] = CM3218x_CMD_DEFAULT;
>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_WH] = CM3218x_WH_DEFAULT;
>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_WL] = CM3218x_WL_DEFAULT;
>>>>>> +
>>>>>> + /* Disable interrupt */
>>>>>> + cm3218x_interrupt_config(chip, 0);
>>>>>> +
>>>>>> + /* Disable Test Mode */
>>>>>> + i2c_smbus_write_word_data(client, CM3218x_REG_ADDR_TEST,
>> 0x0000);
>>>>>> +
>>>>>> + /* Disable device */
>>>>>> + i2c_smbus_write_word_data(client, CM3218x_REG_ADDR_CMD,
>>>>>> + CM3218x_CMD_ALS_DISABLE);
>>>>>> +
>>>>>> + /* Identify device */
>>>>>> + ret = i2c_smbus_read_word_data(client, CM3218x_REG_ADDR_ID);
>>>>>> + if (ret < 0)
>>>>>> + return ret;
>>>>>> + switch (ret & 0xFF) {
>>>>>> + case 0x18:
>>>>>> + cmdev = chip->cmdev = &cm3218;
>>>>>> + if (ret & 0x0800)
>>>>>> + cmdev->int_type = INT_TYPE_I2C;
>>>>>> + else
>>>>>> + cmdev->int_type = INT_TYPE_SMBUS;
>>>>>> + break;
>>>>>> + case 0x81:
>>>>>> + cmdev = chip->cmdev = &cm32181;
>>>>>> + break;
>>>>>> + case 0x82:
>>>>>> + cmdev = chip->cmdev = &cm32182;
>>>>>> + break;
>>>>>> + default:
>>>>>> + return -ENODEV;
>>>>>> + }
>>>>>> +
>>>>>> + if (ACPI_HANDLE(&client->dev)) {
>>>>>> + /* Load from ACPI */
>>>>>> + cpm_elem_count = cm3218x_acpi_get_cpm_info(client, "CPM0",
>>>>>> + ARRAY_SIZE(cpm_elems),
>>>>>> + cpm_elems);
>>>>>> + if (cpm_elem_count > 0) {
>>>>>> + int header_num = 3;
>>>>>> + int reg_num = cpm_elem_count - header_num;
>>>>>> +
>>>>>> + cmdev->regs_bmp = cpm_elems[2];
>>>>>> + for (i = 0; i < reg_num; i++)
>>>>>> + if (cmdev->regs_bmp & (1<<i))
>>>>>> + chip->conf_regs[i] =
>>>>>> + cpm_elems[header_num+i];
>>>>>> + }
>>>>>> +
>>>>>> + cpm_elem_count = cm3218x_acpi_get_cpm_info(client, "CPM1",
>>>>>> + ARRAY_SIZE(cpm_elems),
>>>>>> + cpm_elems);
>>>>>> + if (cpm_elem_count > 0) {
>>>>>> + cmdev->mlux_per_bit = (int)cpm_elems[0] / 100;
>>>>>> + cmdev->calibscale = (int)cpm_elems[1];
>>>>>> + }
>>>>>> + }
>>>>>> +
>>>>>> + /* Force to disable interrupt */
>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD] &=
>> ~CM3218x_CMD_ALS_INT_EN;
>>>>>> +
>>>>>> + /* Initialize registers*/
>>>>> whitespace
>>>>>
>>>>>> + for (i = 0; i < CM3218x_CONF_REG_NUM; i++) {
>>>>>> + if (cmdev->regs_bmp & (1<<i)) {
>>>>>> + ret = i2c_smbus_write_word_data(client, i,
>>>>>> + chip->conf_regs[i]);
>>>>>> + if (ret < 0)
>>>>>> + return ret;
>>>>>> + }
>>>>>> + }
>>>>>> +
>>>>>> + return 0;
>>>>>> +}
>>>>>> +
>>>>>> +/**
>>>>>> + *  cm3218x_read_als_it() - Get sensor integration time (ms)
>>>>>> + *  @cm3218x: pointer of struct cm3218x
>>>>>> + *  @val2: pointer of int to load the als_it value.
>>>>>> + *
>>>>>> + *  Report the current integartion time by millisecond.
>>>>> integration time in milliseconds
>>>>>
>>>>>> + *
>>>>>> + *  Return: IIO_VAL_INT_PLUS_MICRO for success, otherwise
>> -EINVAL.
>>>>>> + */
>>>>>> +static int cm3218x_read_als_it(struct cm3218x_chip *chip, int
>>>> *val2)
>>>>>> +{
>>>>>> + struct cmdev *cmdev = chip->cmdev;
>>>>>> + u16 als_it;
>>>>>> + int i;
>>>>>> +
>>>>>> + als_it = chip->conf_regs[CM3218x_REG_ADDR_CMD];
>>>>>> + als_it &= CM3218x_CMD_ALS_IT_MASK;
>>>>>> + als_it >>= CM3218x_CMD_ALS_IT_SHIFT;
>>>>>> + for (i = 0; i < cmdev->num_als_it; i++) {
>>>>>> + if (als_it == cmdev->als_it_bits[i]) {
>>>>>> + *val2 = cmdev->als_it_values[i];
>>>>>> + return IIO_VAL_INT_PLUS_MICRO;
>>>>>> + }
>>>>>> + }
>>>>>> +
>>>>>> + return -EINVAL;
>>>>>> +}
>>>>>> +
>>>>>> +/**
>>>>>> + * cm3218x_write_als_it() - Write sensor integration time
>>>>>> + * @cm3218x: pointer of struct cm3218x.
>>>>>> + * @val: integration time by millisecond.
>>>>>> + *
>>>>>> + * Convert integration time (ms) to sensor value.
>>>>>> + *
>>>>>> + * Return: i2c_smbus_write_word_data command return value.
>>>>>> + */
>>>>>> +static int cm3218x_write_als_it(struct cm3218x_chip *chip, int
>> val)
>>>>>> +{
>>>>>> + struct i2c_client *client = chip->client;
>>>>>> + struct cmdev *cmdev = chip->cmdev;
>>>>>> + u16 als_it;
>>>>>> + int ret, i;
>>>>>> +
>>>>>> + for (i = 0; i < cmdev->num_als_it; i++)
>>>>>> + if (val <= cmdev->als_it_values[i])
>>>>>> + break;
>>>>>> + if (i >= cmdev->num_als_it)
>>>>>> + i = cmdev->num_als_it - 1;
>>>>>> +
>>>>>> + als_it = cmdev->als_it_bits[i];
>>>>>> + als_it <<= CM3218x_CMD_ALS_IT_SHIFT;
>>>>>> +
>>>>>> + mutex_lock(&chip->lock);
>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD] &=
>>>>>> + ~CM3218x_CMD_ALS_IT_MASK;
>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD] |=
>>>>>> + als_it;
>>>>>> + ret = i2c_smbus_write_word_data(client, CM3218x_REG_ADDR_CMD,
>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD]);
>>>>>> + mutex_unlock(&chip->lock);
>>>>>> +
>>>>>> + return ret;
>>>>>> +}
>>>>>> +
>>>>>> +/**
>>>>>> + * cm3218x_get_lux() - report current lux value
>>>>>> + * @cm3218x: pointer of struct cm3218x.
>>>>>> + *
>>>>>> + * Convert sensor raw data to lux.  It depends on integration
>>>>>> + * time and claibscale variable.
>>>>> calibscale
>>>>>
>>>>>> + *
>>>>>> + * Return: Positive value is lux, otherwise is error code.
>>>>>> + */
>>>>>> +static int cm3218x_get_lux(struct cm3218x_chip *chip)
>>>>>> +{
>>>>>> + struct i2c_client *client = chip->client;
>>>>>> + struct cmdev *cmdev = chip->cmdev;
>>>>>> + int ret;
>>>>>> + int als_it;
>>>>>> + int lux;
>>>>> lux variable is not needed
>>>>>
>>>>>> + u64 tmp;
>>>>>> +
>>>>>> + /* Calculate mlux per bit based on als_it */
>>>>>> + ret = cm3218x_read_als_it(chip, &als_it);
>>>>>> + if (ret < 0)
>>>>>> + return -EINVAL;
>>>>>> + tmp = (__force u64)cmdev->mlux_per_bit;
>>>>>> + tmp *= cmdev->mlux_per_bit_base_it;
>>>>>> + tmp = div_u64(tmp, als_it);
>>>>>> +
>>>>>> + /* Get als_raw */
>>>>>> + if (!(chip->conf_regs[CM3218x_REG_ADDR_CMD] &
>>>> CM3218x_CMD_ALS_INT_EN))
>>>>>> + chip->als_raw = i2c_smbus_read_word_data(
>>>>>> + client,
>>>>>> + CM3218x_REG_ADDR_ALS);
>>>>>> + if (chip->als_raw < 0)
>>>>>> + return chip->als_raw;
>>>>>> +
>>>>>> + tmp *= chip->als_raw;
>>>>>> + tmp *= cmdev->calibscale;
>>>>>> + tmp = div_u64(tmp, CM3218x_CALIBSCALE_RESOLUTION);
>>>>>> + tmp = div_u64(tmp, MLUX_PER_LUX);
>>>>>> +
>>>>>> + if (tmp > 0xFFFF)
>>>>>> + tmp = 0xFFFF;
>>>>>> +
>>>>>> + lux = (int)tmp;
>>>>>> + return lux;
>>>>>> +}
>>>>>> +
>>>>>> +static int cm3218x_read_raw(struct iio_dev *indio_dev,
>>>>>> + struct iio_chan_spec const *chan,
>>>>>> + int *val, int *val2, long mask)
>>>>>> +{
>>>>>> + struct cm3218x_chip *chip = iio_priv(indio_dev);
>>>>>> + struct cmdev *cmdev = chip->cmdev;
>>>>>> + int ret;
>>>>>> +
>>>>>> + switch (mask) {
>>>>>> + case IIO_CHAN_INFO_PROCESSED:
>>>>>> + ret = cm3218x_get_lux(chip);
>>>>>> + if (ret < 0)
>>>>>> + return ret;
>>>>>> + *val = ret;
>>>>>> + return IIO_VAL_INT;
>>>>>> + case IIO_CHAN_INFO_CALIBSCALE:
>>>>>> + *val = cmdev->calibscale;
>>>>>> + return IIO_VAL_INT;
>>>>>> + case IIO_CHAN_INFO_INT_TIME:
>>>>>> + *val = 0;
>>>>>> + ret = cm3218x_read_als_it(chip, val2);
>>>>>> + return ret;
>>>>>> + }
>>>>>> +
>>>>>> + return -EINVAL;
>>>>>> +}
>>>>>> +
>>>>>> +static int cm3218x_write_raw(struct iio_dev *indio_dev,
>>>>>> + struct iio_chan_spec const *chan,
>>>>>> + int val, int val2, long mask)
>>>>>> +{
>>>>>> + struct cm3218x_chip *chip = iio_priv(indio_dev);
>>>>>> + struct cmdev *cmdev = chip->cmdev;
>>>>>> + int ret;
>>>>> ret not needed
>>>>>
>>>>>> +
>>>>>> + switch (mask) {
>>>>>> + case IIO_CHAN_INFO_CALIBSCALE:
>>>>>> + cmdev->calibscale = val;
>>>>>> + return val;
>>>>>> + case IIO_CHAN_INFO_INT_TIME:
>>>>> val==0 could be checked here
>>>>>
>>>>>> + ret = cm3218x_write_als_it(chip, val2);
>>>>>> + return ret;
>>>>>> + }
>>>>>> +
>>>>>> + return -EINVAL;
>>>>>> +}
>>>>>> +
>>>>>> +/**
>>>>>> + * cm3218x_get_it_available() - Get available ALS IT value
>>>>>> + * @dev: pointer of struct device.
>>>>>> + * @attr: pointer of struct device_attribute.
>>>>>> + * @buf: pointer of return string buffer.
>>>>>> + *
>>>>>> + * Display the available integration time values by millisecond.
>>>>>> + *
>>>>>> + * Return: string length.
>>>>>> + */
>>>>>> +static ssize_t cm3218x_get_it_available(struct device *dev,
>>>>>> + struct device_attribute *attr, char *buf)
>>>>>> +{
>>>>>> + struct cm3218x_chip *chip = iio_priv(dev_to_iio_dev(dev));
>>>>>> + struct cmdev *cmdev = chip->cmdev;
>>>>>> + int i, len;
>>>>>> +
>>>>>> + for (i = 0, len = 0; i < cmdev->num_als_it; i++)
>>>>>> + len += sprintf(buf + len, "0.%06u ", cmdev->als_it_values[i]);
>>>>> scnprintf(buf+len, PAGESIZE-len, ...) could be used
>>>>>
>>>>>> + return len + sprintf(buf + len, "\n");
>>>>>> +}
>>>>>> +
>>>>>> +/**
>>>>>> + * cm3218x_threshold_update() - Update the threshold registers.
>>>>>> + * @dev: pointer of struct cm3218x_chip.
>>>>> @chip
>>>>>
>>>>>> + * @percent: +/- percent.
>>>>>> + *
>>>>>> + * Based on the current ALS value, tupdate the hi and low
>> threshold
>>>>>> registers.
>>>>>> + *
>>>>>> + * Return: string length.
>>>>> definitely not the string length
>>>>>
>>>>>> + */
>>>>>> +static int cm3218x_threshold_update(struct cm3218x_chip *chip,
>> int
>>>>>> percent)
>>>>>> +{
>>>>>> + struct i2c_client *client = chip->client;
>>>>>> + int ret;
>>>>>> + int wh, wl;
>>>>>> +
>>>>>> + ret = chip->als_raw = i2c_smbus_read_word_data(client,
>>>>>> + CM3218x_REG_ADDR_ALS);
>>>>>> + if (ret < 0)
>>>>>> + return ret;
>>>>>> +
>>>>>> + wh = wl = ret;
>>>>>> + ret *= percent;
>>>>>> + ret /= 100;
>>>>>> + if (ret < 1)
>>>>>> + ret = 1;
>>>>>> + wh += ret;
>>>>>> + wl -= ret;
>>>>>> + if (wh > 65535)
>>>>>> + wh = 65535;
>>>>>> + if (wl < 0)
>>>>>> + wl = 0;
>>>>>> +
>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_WH] = wh;
>>>>>> + ret = i2c_smbus_write_word_data(
>>>>>> + client,
>>>>>> + CM3218x_REG_ADDR_WH,
>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_WH]);
>>>>>> + if (ret < 0)
>>>>>> + return ret;
>>>>>> +
>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_WL] = wl;
>>>>>> + ret = i2c_smbus_write_word_data(
>>>>>> + client,
>>>>>> + CM3218x_REG_ADDR_WL,
>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_WL]);
>>>>> just
>>>>> return ret;
>>>>>
>>>>>> + if (ret < 0)
>>>>>> + return ret;
>>>>>> +
>>>>>> + return 0;
>>>>>> +}
>>>>>> +
>>>>>> +/**
>>>>>> + * cm3218x_event_handler() - Interrupt handling routine.
>>>>>> + * @irq: irq number.
>>>>>> + * @private: pointer of void.
>>>>>> + *
>>>>>> + * Clean interrupt and reset threshold registers.
>>>>>> + *
>>>>>> + * Return: string length.
>>>>>
>>>>>> + */
>>>>>> +static irqreturn_t cm3218x_event_handler(int irq, void *private)
>>>>>> +{
>>>>>> + struct iio_dev *dev_info = private;
>>>>>> + struct cm3218x_chip *chip = iio_priv(dev_info);
>>>>>> + int ret;
>>>>>> +
>>>>>> + mutex_lock(&chip->lock);
>>>>>> +
>>>>>> + /* Disable interrupt */
>>>>>> + ret = cm3218x_interrupt_config(chip, 0);
>>>>>> + if (ret < 0)
>>>>>> + goto error_handler_unlock;
>>>>>> +
>>>>>> + /* Update Hi/Lo windows */
>>>>>> + ret = cm3218x_threshold_update(chip, CM3218x_THRESHOLD_PERCENT);
>>>>>> + if (ret < 0)
>>>>>> + goto error_handler_unlock;
>>>>>> +
>>>>>> + /* Enable interrupt */
>>>>>> + ret = cm3218x_interrupt_config(chip, 1);
>>>>>> + if (ret < 0)
>>>>>> + goto error_handler_unlock;
>>>>>> +
>>>>>> + mutex_unlock(&chip->lock);
>>>>>> +
>>>>>> + return IRQ_HANDLED;
>>>>>> +
>>>>>> +error_handler_unlock:
>>>>>> + mutex_unlock(&chip->lock);
>>>>>> + return IRQ_NONE;
>>>>> I think it should be IRQ_HANDLED always
>>>>> there is no check if the interrupt indeed stems from this device
>>>>>
>>>>>> +}
>>>>>> +
>>>>>> +static const struct iio_chan_spec cm3218x_channels[] = {
>>>>>> + {
>>>>>> + .type = IIO_LIGHT,
>>>>>> + .info_mask_separate =
>>>>>> + BIT(IIO_CHAN_INFO_PROCESSED) |
>>>>>> + BIT(IIO_CHAN_INFO_CALIBSCALE) |
>>>>>> + BIT(IIO_CHAN_INFO_INT_TIME),
>>>>>> + }
>>>>>> +};
>>>>>> +
>>>>>> +static IIO_DEVICE_ATTR(in_illuminance_integration_time_available,
>>>>>> + S_IRUGO, cm3218x_get_it_available, NULL, 0);
>>>>>> +
>>>>>> +static struct attribute *cm3218x_attributes[] = {
>>>>>> +
>> &iio_dev_attr_in_illuminance_integration_time_available.dev_attr.attr,
>>>>>> + NULL,
>>>>>> +};
>>>>>> +
>>>>>> +static const struct attribute_group cm3218x_attribute_group = {
>>>>>> + .attrs = cm3218x_attributes
>>>>>> +};
>>>>>> +
>>>>>> +static const struct iio_info cm3218x_info = {
>>>>>> + .driver_module = THIS_MODULE,
>>>>>> + .read_raw = &cm3218x_read_raw,
>>>>>> + .write_raw = &cm3218x_write_raw,
>>>>>> + .attrs = &cm3218x_attribute_group,
>>>>>> +};
>>>>>> +
>>>>>> +static int cm3218x_probe(struct i2c_client *client,
>>>>>> + const struct i2c_device_id *id)
>>>>>> +{
>>>>>> + struct cm3218x_chip *chip;
>>>>>> + struct iio_dev *indio_dev;
>>>>>> + int ret;
>>>>>> +
>>>>>> + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
>>>>>> + if (!indio_dev) {
>>>>>> + dev_err(&client->dev, "devm_iio_device_alloc failed\n");
>>>>>> + return -ENOMEM;
>>>>>> + }
>>>>>> +
>>>>>> + chip = iio_priv(indio_dev);
>>>>>> + i2c_set_clientdata(client, indio_dev);
>>>>>> + chip->client = client;
>>>>>> +
>>>>>> + mutex_init(&chip->lock);
>>>>>> + indio_dev->dev.parent = &client->dev;
>>>>>> + indio_dev->channels = cm3218x_channels;
>>>>>> + indio_dev->num_channels = ARRAY_SIZE(cm3218x_channels);
>>>>>> + indio_dev->info = &cm3218x_info;
>>>>>> + if (id && id->name)
>>>>>> + indio_dev->name = id->name;
>>>>>> + else
>>>>>> + indio_dev->name = (char *)dev_name(&client->dev);
>>>>>> + indio_dev->modes = INDIO_DIRECT_MODE;
>>>>>> +
>>>>>> + ret = cm3218x_reg_init(chip);
>>>>>> + if (ret) {
>>>>>> + dev_err(&client->dev,
>>>>>> + "%s: register init failed\n",
>>>>>> + __func__);
>>>>>> + return ret;
>>>>>> + }
>>>>>> +
>>>>>> + if (client->irq) {
>>>>>> + ret = request_threaded_irq(client->irq,
>>>>>> + NULL,
>>>>>> + cm3218x_event_handler,
>>>>>> + IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
>>>>>> + "cm3218x_event",
>>>>>> + indio_dev);
>>>>>> +
>>>>>> + if (ret < 0) {
>>>>>> + dev_err(&client->dev, "irq request error %d\n",
>>>>>> + -ret);
>>>>>> + goto error_disable_int;
>>>>>> + }
>>>>>> + }
>>>>>> +
>>>>>> + ret = iio_device_register(indio_dev);
>>>>>> + if (ret < 0) {
>>>>>> + dev_err(&client->dev,
>>>>>> + "%s: regist device failed\n",
>>>>>> + __func__);
>>>>>> + goto error_free_irq;
>>>>>> + }
>>>>>> +
>>>>>> + if (client->irq) {
>>>>>> + ret = cm3218x_threshold_update(chip, CM3218x_THRESHOLD_PERCENT);
>>>>>> + if (ret < 0)
>>>>>> + goto error_free_irq;
>>>>>> +
>>>>>> + ret = cm3218x_interrupt_config(chip, 1);
>>>>>> + if (ret < 0)
>>>>>> + goto error_free_irq;
>>>>>> + }
>>>>>> +
>>>>>> + return 0;
>>>>>> +
>>>>>> +error_free_irq:
>>>>>> + free_irq(client->irq, indio_dev);
>>>>>> +error_disable_int:
>>>>>> + cm3218x_interrupt_config(chip, 0);
>>>>>> + return ret;
>>>>>> +}
>>>>>> +
>>>>>> +static int cm3218x_remove(struct i2c_client *client)
>>>>>> +{
>>>>>> + struct iio_dev *indio_dev = i2c_get_clientdata(client);
>>>>>> + struct cm3218x_chip *chip = iio_priv(indio_dev);
>>>>>> +
>>>>>> + cm3218x_interrupt_config(chip, 0);
>>>>>> + if (client->irq)
>>>>>> + free_irq(client->irq, indio_dev);
>>>>>> + iio_device_unregister(indio_dev);
>>>>>> + return 0;
>>>>>> +}
>>>>>> +
>>>>>> +static const struct i2c_device_id cm3218x_id[] = {
>>>>>> + { "cm3218x", 0},
>>>>>> + { }
>>>>>> +};
>>>>>> +
>>>>>> +MODULE_DEVICE_TABLE(i2c, cm3218x_id);
>>>>>> +
>>>>>> +static const struct of_device_id cm3218x_of_match[] = {
>>>>>> + { .compatible = "capella,cm3218x" },
>>>>>> + { }
>>>>>> +};
>>>>>> +
>>>>>> +static const struct acpi_device_id cm3218x_acpi_match[] = {
>>>>>> + { "CPLM3218", 0},
>>>>>> + {},
>>>>>> +};
>>>>>> +
>>>>>> +MODULE_DEVICE_TABLE(acpi, cm3218x_acpi_match);
>>>>>> +
>>>>>> +static struct i2c_driver cm3218x_driver = {
>>>>>> + .driver = {
>>>>>> + .name = "cm3218x",
>>>>>> + .acpi_match_table = ACPI_PTR(cm3218x_acpi_match),
>>>>>> + .of_match_table = of_match_ptr(cm3218x_of_match),
>>>>>> + .owner = THIS_MODULE,
>>>>>> + },
>>>>>> + .id_table = cm3218x_id,
>>>>>> + .probe = cm3218x_probe,
>>>>>> + .remove = cm3218x_remove,
>>>>>> +};
>>>>>> +
>>>>>> +module_i2c_driver(cm3218x_driver);
>>>>>> +
>>>>>> +MODULE_AUTHOR("Kevin Tsai <ktsai-GubuWUlQtMwciDkP5Hr2oA@public.gmane.org>");
>>>>>> +MODULE_DESCRIPTION("CM3218x ambient light sensor driver");
>>>>>> +MODULE_LICENSE("GPL");
>>>>>>
>>>>> -- 
>>>>>
>>>>> Peter Meerwald
>>>>> +43-664-2444418 (mobile)

Re: [PATCH V1 1/1] iio: add Capella cm3218x ambient light sensor driver.

[Jonathan Cameron]

On 21/03/14 22:21, Srinivas Pandruvada wrote:
> On 03/21/2014 03:05 PM, Jonathan Cameron wrote:
>>
>> On March 20, 2014 11:19:49 PM GMT+00:00, Srinivas Pandruvada <srinivas.pandruvada-VuQAYsv1563Yd54FQh9/CA@public.gmane.org> wrote:
>>> On 03/19/2014 11:54 PM, Jonathan Cameron wrote:
>>>> On March 20, 2014 12:58:02 AM GMT+00:00, Kevin Tsai
>>> <ktsai-GubuWUlQtMwciDkP5Hr2oA@public.gmane.org> wrote:
>>>>> Hi Peter,
>>>>>
>>>>> Thanks for your advise.  I'll update my code.
>>>>>
>>>>> ACPI is optional.  Most PC manufactory may store the lens factor to
>>>>> ACPI
>>>>> table.  But, phone customers like to modify the parameters inside
>>> code.
>>>>> CM3218 have two versions.  The old version need to read SMBus ARA
>>>>> register
>>>>> to clean interrupt.  That's why I need to change I2C chip address.
>>>>> Please
>>>>> guid me if you have a better way to access two addresses.
>>>> Would the smbus alert infrastructure in drivers/i2ç/i2c-smbus.c help?
>>> The smbus alert notification are based on the underlying i2c
>>> controller.
>>> Not every controller supports. I can see only one controller driver in
>>> the upstream Linux added this support.
>> To my mind adding wider support for the alert functionality will be the way forward.
>>
>> Wolfram, any idea why so few bus drivers implement the smbus alert stuff? I would
>>   guess you won't be against wider support of this using existing infrastructure?
> SMALRT is a physical pin connection. Most of the i2C controlleron X86 will have no option to connect
> SMALRT signal. So may be we need a common API to read instead, to read and get status.
Unless I am missing something, it's just a shared interrupt really common to whatever
devices are connected to the smbus controller.  If the typical i2c controller on x86
doesn't have an interrupt line (and one isn't provided by some other route) then
the driver as a whole will need polled support.

They will still need a means of resetting the alert line via the ara address though
so we probably need some means of supporting that...  Perhaps the approach used
in this driver is the right way to go, but if it is then it should be wrapped
up in a core function rather than exposing the address switching in the driver itself.

Remember there may well be more than one device with smbus alert support on the bus.
The approach here will clear the interrupt on one of them but not necessarily this device.

I hate to say it but anyone who uses an smbus alert equipped device without actually
having a shared interrupt line is asking for trouble.  Some devices offer an alternative
means of deasserting the interrupt (max1363) thus allowing use with the smbus alert
address querying, or with a normal interrupt line.  I don't suppose that is the case here?

Jonathan
>
> Thanks,
> Srinivas
>
>>> Thanks,
>>> Srinivas
>>>
>>>>> Thanks.
>>>>>
>>>>> Kevin Tsai
>>>>> 03/19/14
>>>>>
>>>>> ----- Original Message -----
>>>>> From: "Peter Meerwald" <pmeerw-jW+XmwGofnusTnJN9+BGXg@public.gmane.org>
>>>>> To: "Kevin Tsai" <ktsai-GubuWUlQtMwciDkP5Hr2oA@public.gmane.org>
>>>>> Cc: "Jonathan Cameron" <jic23-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>;
>>> <linux-iio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
>>>>> Sent: Wednesday, March 19, 2014 11:07
>>>>> Subject: Re: [PATCH V1 1/1] iio: add Capella cm3218x ambient light
>>>>> sensor
>>>>> driver.
>>>>>
>>>>>
>>>>>>> Add Capella Microsystem CM3218x family Ambient Light Sensor IIO
>>>>> driver.
>>>>>>> This driver will convert raw data to lux value.  Default
>>> parameters
>>>>> are
>>>>>>> for reference only.  It will detect ACPI table to load per-system
>>>>>>> manufacturing
>>>>>>> parameters.
>>>>>> nitpicking below
>>>>>>
>>>>>>> ---
>>>>>>>    .../devicetree/bindings/i2c/trivial-devices.txt    |   1 +
>>>>>>>    drivers/iio/light/Kconfig                          |  11 +
>>>>>>>    drivers/iio/light/Makefile                         |   1 +
>>>>>>>    drivers/iio/light/cm3218x.c                        | 769
>>>>>>> +++++++++++++++++++++
>>>>>>>    4 files changed, 782 insertions(+)
>>>>>>>    create mode 100644 drivers/iio/light/cm3218x.c
>>>>>>>
>>>>>>> diff --git
>>>>> a/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>>>>>>> b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>>>>>>> index 1a1ac2e..29e7eae 100644
>>>>>>> --- a/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>>>>>>> +++ b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>>>>>>> @@ -17,6 +17,7 @@ at,24c08 i2c serial eeprom  (24cxx)
>>>>>>>    atmel,24c02 i2c serial eeprom  (24cxx)
>>>>>>>    atmel,at97sc3204t i2c trusted platform module (TPM)
>>>>>>>    capella,cm32181 CM32181: Ambient Light Sensor
>>>>>>> +capella,cm3218x CM3218x: Ambient Light Sensor
>>>>>>>    catalyst,24c32 i2c serial eeprom
>>>>>>>    dallas,ds1307 64 x 8, Serial, I2C Real-Time Clock
>>>>>>>    dallas,ds1338 I2C RTC with 56-Byte NV RAM
>>>>>>> diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
>>>>>>> index d12b2a0..45a22a6 100644
>>>>>>> --- a/drivers/iio/light/Kconfig
>>>>>>> +++ b/drivers/iio/light/Kconfig
>>>>>>> @@ -38,6 +38,17 @@ config CM32181
>>>>>>>    To compile this driver as a module, choose M here:
>>>>>>>    the module will be called cm32181.
>>>>>>>
>>>>>>> +config CM3218X
>>>>>>> + depends on I2C
>>>>>> is there an ACPI dependency?
>>>>>>
>>>>>>> + tristate "CM3218x driver"
>>>>>>> + help
>>>>>>> + Say Y here if you use cm3218x.
>>>>>>> + This option enables ambient light sensor using
>>>>>>> + Capella cm3218x device driver.
>>>>>>> +
>>>>>>> + To compile this driver as a module, choose M here:
>>>>>>> + the module will be called cm3218x.
>>>>>>> +
>>>>>>>    config CM36651
>>>>>>>    depends on I2C
>>>>>>>    tristate "CM36651 driver"
>>>>>>> diff --git a/drivers/iio/light/Makefile
>>> b/drivers/iio/light/Makefile
>>>>>>> index 60e35ac..a506c23 100644
>>>>>>> --- a/drivers/iio/light/Makefile
>>>>>>> +++ b/drivers/iio/light/Makefile
>>>>>>> @@ -6,6 +6,7 @@
>>>>>>>    obj-$(CONFIG_ADJD_S311) += adjd_s311.o
>>>>>>>    obj-$(CONFIG_APDS9300) += apds9300.o
>>>>>>>    obj-$(CONFIG_CM32181) += cm32181.o
>>>>>>> +obj-$(CONFIG_CM3218X) += cm3218x.o
>>>>>>>    obj-$(CONFIG_CM36651) += cm36651.o
>>>>>>>    obj-$(CONFIG_GP2AP020A00F) += gp2ap020a00f.o
>>>>>>>    obj-$(CONFIG_HID_SENSOR_ALS) += hid-sensor-als.o
>>>>>>> diff --git a/drivers/iio/light/cm3218x.c
>>>>> b/drivers/iio/light/cm3218x.c
>>>>>>> new file mode 100644
>>>>>>> index 0000000..e422f68
>>>>>>> --- /dev/null
>>>>>>> +++ b/drivers/iio/light/cm3218x.c
>>>>>>> @@ -0,0 +1,769 @@
>>>>>>> +/*
>>>>>>> + * Copyright (C) 2014 Capella Microsystems Inc.
>>>>>>> + * Author: Kevin Tsai <ktsai-GubuWUlQtMwciDkP5Hr2oA@public.gmane.org>
>>>>>>> + *
>>>>>>> + * This program is free software; you can redistribute it and/or
>>>>> modify
>>>>>>> it
>>>>>>> + * under the terms of the GNU General Public License version 2,
>>> as
>>>>>>> published
>>>>>>> + * by the Free Software Foundation.
>>>>>>> + *
>>>>>>> + * Special thanks Srinivas Pandruvada
>>>>>>> <srinivas.pandruvada-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
>>>>>>> + * help to add ACPI support.
>>>>>>> + *
>>>>>>> + */
>>>>>>> +
>>>>>>> +#include <linux/delay.h>
>>>>>>> +#include <linux/err.h>
>>>>>>> +#include <linux/i2c.h>
>>>>>>> +#include <linux/mutex.h>
>>>>>>> +#include <linux/module.h>
>>>>>>> +#include <linux/interrupt.h>
>>>>>>> +#include <linux/regulator/consumer.h>
>>>>>>> +#include <linux/iio/iio.h>
>>>>>>> +#include <linux/iio/sysfs.h>
>>>>>>> +#include <linux/iio/events.h>
>>>>>>> +#include <linux/init.h>
>>>>>>> +#include <linux/acpi.h>
>>>>>>> +
>>>>>>> +/* Registers Address */
>>>>>>> +#define CM3218x_REG_ADDR_CMD 0x00
>>>>>>> +#define CM3218x_REG_ADDR_WH 0x01
>>>>>>> +#define CM3218x_REG_ADDR_WL 0x02
>>>>>>> +#define CM3218x_REG_ADDR_TEST 0x03
>>>>>> inconsistent whitespace allover
>>>>>>
>>>>>>> +#define CM3218x_REG_ADDR_ALS 0x04
>>>>>>> +#define CM3218x_REG_ADDR_STATUS 0x06
>>>>>>> +#define CM3218x_REG_ADDR_ID 0x07
>>>>>>> +
>>>>>>> +/* Number of Configurable Registers */
>>>>>>> +#define CM3218x_CONF_REG_NUM 16
>>>>>>> +
>>>>>>> +/* CMD register */
>>>>>>> +#define CM3218x_CMD_ALS_DISABLE 0x01
>>>>>>> +#define CM3218x_CMD_ALS_INT_EN 0x02
>>>>>>> +#define CM3218x_CMD_ALS_THRES_WINDOW 0x04
>>>>>>> +
>>>>>>> +#define CM3218x_CMD_ALS_PERS_SHIFT 4
>>>>>>> +#define CM3218x_CMD_ALS_PERS_MASK (0x03 <<
>>>>> CM3218x_CMD_ALS_PERS_SHIFT)
>>>>>>> +#define CM3218x_CMD_ALS_PERS_DEFAULT (0x01 <<
>>>>>>> CM3218x_CMD_ALS_PERS_SHIFT)
>>>>>>> +
>>>>>>> +#define CM3218x_CMD_ALS_IT_SHIFT 6
>>>>>>> +#define CM3218x_CMD_ALS_IT_MASK (0x0F <<
>>> CM3218x_CMD_ALS_IT_SHIFT)
>>>>>>> +#define CM3218x_CMD_ALS_IT_DEFAULT (0x01 <<
>>>>> CM3218x_CMD_ALS_IT_SHIFT)
>>>>>>> +
>>>>>>> +#define CM3218x_CMD_ALS_HS_SHIFT 11
>>>>>>> +#define CM3218x_CMD_ALS_HS_MASK (0x01 <<
>>> CM3218x_CMD_ALS_HS_SHIFT)
>>>>>>> +#define CM3218x_CMD_ALS_HS_DEFAULT (0x00 <<
>>>>> CM3218x_CMD_ALS_HS_SHIFT)
>>>>>>> +
>>>>>>> +#define CM3218x_CMD_DEFAULT (CM3218x_CMD_ALS_THRES_WINDOW |\
>>>>>>> + CM3218x_CMD_ALS_PERS_DEFAULT |\
>>>>>>> + CM3218x_CMD_ALS_IT_DEFAULT |\
>>>>>>> + CM3218x_CMD_ALS_HS_DEFAULT)
>>>>>>> +
>>>>>>> +#define CM3218x_WH_DEFAULT 0xFFFF
>>>>>>> +#define CM3218x_WL_DEFAULT 0x0000
>>>>>>> +
>>>>>>> +#define CM3218x_CALIBSCALE_DEFAULT 100000
>>>>>>> +#define CM3218x_CALIBSCALE_RESOLUTION 100000
>>>>>>> +#define MLUX_PER_LUX 1000
>>>>>> CM3218x prefix missing
>>>>>>
>>>>>> the lowercase x in macros is a bit weird for my taste
>>>>>>
>>>>>>> +#define CM3218x_THRESHOLD_PERCENT 10 /* 10 percent */
>>>>>>> +
>>>>>>> +/* CM3218 Family */
>>>>>>> +#define CM3218_MLUX_PER_BIT_DEFAULT 5 /* Depend on system */
>>>>>>> +#define CM3218_MLUX_PER_BIT_BASE_IT 800000
>>>>>>> +static int CM3218_als_it_bits[] = {0, 1, 2, 3};
>>>>>>> +static int CM3218_als_it_values[] = {100000, 200000, 400000,
>>>>> 800000};
>>>>>> const missing
>>>>>>
>>>>>>> +
>>>>>>> +/* CM32181 Family */
>>>>>>> +#define CM32181_MLUX_PER_BIT_DEFAULT 5
>>>>>>> +#define CM32181_MLUX_PER_BIT_BASE_IT 800000
>>>>>>> +static int CM32181_als_it_bits[] = {12, 8, 0, 1, 2, 3};
>>>>>>> +static int CM32181_als_it_values[] = {
>>>>>>> + 25000, 50000, 100000, 200000, 400000, 800000};
>>>>>> const missing
>>>>>>
>>>>>>> +
>>>>>>> +/* CM32182 Family */
>>>>>>> +#define CM32182_MLUX_PER_BIT_DEFAULT 5
>>>>>>> +#define CM32182_MLUX_PER_BIT_BASE_IT 800000
>>>>>>> +static int CM32182_als_it_bits[] = {12, 8, 0, 1, 2, 3};
>>>>>>> +static int CM32182_als_it_values[] = {
>>>>>>> + 25000, 50000, 100000, 200000, 400000, 800000};
>>>>>> const missing
>>>>>>
>>>>>> these definitions are largely identical and could be dropped; they
>>>>> are
>>>>>> only used to fill device-specific tables below; why have a separate
>>>>>> define here?
>>>>>>
>>>>>>> +
>>>>>>> +struct cmdev {
>>>>>> prefix?
>>>>>>
>>>>>>> + u32 family_id;
>>>>>>> + int int_type;
>>>>>>> +#define INT_TYPE_SMBUS 0
>>>>>>> +#define INT_TYPE_I2C 1
>>>>>> prefix?
>>>>>>
>>>>>>> + int regs_bmp;
>>>>>>> + int calibscale;
>>>>>>> + int mlux_per_bit;
>>>>>>> + int mlux_per_bit_base_it;
>>>>>>> + int *als_it_bits;
>>>>>>> + int *als_it_values;
>>>>>>> + int num_als_it;
>>>>>>> +};
>>>>>>> +
>>>>>>> +static struct cmdev cm3218 = {
>>>>>>> + 3218, INT_TYPE_SMBUS, 0x0F, CM3218x_CALIBSCALE_DEFAULT,
>>>>>>> + CM3218_MLUX_PER_BIT_DEFAULT, CM3218_MLUX_PER_BIT_BASE_IT,
>>>>>>> + CM3218_als_it_bits, CM3218_als_it_values,
>>>>>>> + ARRAY_SIZE(CM3218_als_it_bits)};
>>>>>>> +
>>>>>>> +static struct cmdev cm32181 = {
>>>>>>> + 32181, INT_TYPE_I2C, 0x0F, CM3218x_CALIBSCALE_DEFAULT,
>>>>>>> + CM32181_MLUX_PER_BIT_DEFAULT, CM32181_MLUX_PER_BIT_BASE_IT,
>>>>>>> + CM32181_als_it_bits, CM32181_als_it_values,
>>>>>>> + ARRAY_SIZE(CM32181_als_it_bits)};
>>>>>>> +
>>>>>>> +static struct cmdev cm32182 = {
>>>>>>> + 32182, INT_TYPE_I2C, 0x0F, CM3218x_CALIBSCALE_DEFAULT,
>>>>>>> + CM32182_MLUX_PER_BIT_DEFAULT, CM32182_MLUX_PER_BIT_BASE_IT,
>>>>>>> + CM32182_als_it_bits, CM32182_als_it_values,
>>>>>>> + ARRAY_SIZE(CM32182_als_it_bits)};
>>>>>>> +
>>>>>>> +struct cm3218x_chip {
>>>>>>> + struct i2c_client *client;
>>>>>>> + struct cmdev *cmdev;
>>>>>>> + struct mutex lock;
>>>>>>> + u16 conf_regs[CM3218x_CONF_REG_NUM];
>>>>>>> + int als_raw;
>>>>>>> +};
>>>>>>> +
>>>>>>> +static int cm3218x_get_lux(struct cm3218x_chip *chip);
>>>>>>> +static int cm3218x_threshold_update(struct cm3218x_chip *chip,
>>> int
>>>>>>> percent);
>>>>>>> +static int cm3218x_read_als_it(struct cm3218x_chip *chip, int
>>>>> *val2);
>>>>>>> +
>>>>>>> +/**
>>>>>>> + * cm3218x_read_ara() - Read ARA register
>>>>>>> + * @cm3218x: pointer of struct cm3218x.
>>>>>> @chip
>>>>>>
>>>>>>> + *
>>>>>>> + * Following SMBus protocol, ARA register is available only when
>>>>>>> interrupt
>>>>>>> + * event happened.  Read it to clean interrupt event.  Otherwise,
>>>>> other
>>>>>>> + * device address/registers will be blocked during interrupt
>>> event.
>>>>>>> + *
>>>>>>> + * Return: 0 for success; otherwise for error code.
>>>>>>> + */
>>>>>>> +static int cm3218x_read_ara(struct cm3218x_chip *chip)
>>>>>>> +{
>>>>>>> + struct i2c_client *client = chip->client;
>>>>>>> + int status;
>>>>>>> + unsigned short addr;
>>>>>>> +
>>>>>> this looks dangerous: temporarily changing the I2C chip address!
>>>>>>
>>>>>>> + addr = client->addr;
>>>>>>> + client->addr = 0x0C;
>>>>>>> + status = i2c_smbus_read_byte(client);
>>>>>>> + client->addr = addr;
>>>>>>> +
>>>>>>> + if (status < 0)
>>>>>>> + return -ENODEV;
>>>>>>> +
>>>>>>> + return status;
>>>>>>> +}
>>>>>>> +
>>>>>>> +/**
>>>>>>> + * cm3218x_interrupt_config() - Enable/Disable CM3218x interrupt
>>>>>>> + * @cm3218x: pointer of struct cm3218x.
>>>>>> @chip: pointer to struct cm3218x_chip
>>>>>>
>>>>>>> + * @enable: 0 to disable; otherwise to enable
>>>>>>> + *
>>>>>>> + * Config CM3218x interrupt control bit.
>>>>>>> + *
>>>>>>> + * Return: 0 for success; otherwise for error code.
>>>>>>> + */
>>>>>>> +static int cm3218x_interrupt_config(struct cm3218x_chip *chip,
>>> int
>>>>>>> enable)
>>>>>>> +{
>>>>>>> + struct i2c_client *client = chip->client;
>>>>>>> + struct cmdev *cmdev = chip->cmdev;
>>>>>>> + int status;
>>>>>>> +
>>>>>>> + if (!cmdev)
>>>>>>> + return -ENODEV;
>>>>>>> +
>>>>>>> + /* Force to clean interrupt */
>>>>>>> + if (cmdev->int_type == INT_TYPE_I2C) {
>>>>>>> + status = i2c_smbus_read_word_data(client,
>>>>>>> + CM3218x_REG_ADDR_STATUS);
>>>>>>> + if (status < 0)
>>>>>>> + cmdev->int_type = INT_TYPE_SMBUS;
>>>>>>> + }
>>>>>>> + if (cmdev->int_type == INT_TYPE_SMBUS)
>>>>>>> + cm3218x_read_ara(chip);
>>>>>>> +
>>>>>>> + if (enable)
>>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD] |=
>>>>>>> + CM3218x_CMD_ALS_INT_EN;
>>>>>>> + else
>>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD] &=
>>>>>>> + ~CM3218x_CMD_ALS_INT_EN;
>>>>>>> +
>>>>>>> + status = i2c_smbus_write_word_data(client, CM3218x_REG_ADDR_CMD,
>>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD]);
>>>>>>> +
>>>>>>> + if (status < 0)
>>>>>>> + return -ENODEV;
>>>>>>> +
>>>>>>> + return status;
>>>>>>> +}
>>>>>>> +
>>>>>>> +/**
>>>>>>> + * cm3218x_acpi_get_cpm_info() - Get CPM object from ACPI
>>>>>>> + * @client pointer of struct i2c_client.
>>>>>>> + * @obj_name pointer of ACPI object name.
>>>>>>> + * @count maximum size of return array.
>>>>>>> + * @vals pointer of array for return elements.
>>>>>>> + *
>>>>>>> + * Convert ACPI CPM table to array. Special thanks Srinivas
>>>>> Pandruvada's
>>>>>>> + * help to implement this routine.
>>>>>>> + *
>>>>>>> + * Return: -ENODEV for fail.  Otherwise is number of elements.
>>>>>>> + */
>>>>>>> +static int cm3218x_acpi_get_cpm_info(struct i2c_client *client,
>>>>> char
>>>>>>> *obj_name,
>>>>>>> + int count, u64 *vals)
>>>>>>> +{
>>>>>>> + acpi_handle handle;
>>>>>>> + struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
>>>>>>> + int i;
>>>>>>> + acpi_status status;
>>>>>>> + union acpi_object *cpm = NULL;
>>>>>> no need to initialize cpm
>>>>>>
>>>>>>> +
>>>>>>> + handle = ACPI_HANDLE(&client->dev);
>>>>>>> + if (!handle)
>>>>>>> + return -ENODEV;
>>>>>>> +
>>>>>>> + status = acpi_evaluate_object(handle, obj_name, NULL, &buffer);
>>>>>>> + if (ACPI_FAILURE(status)) {
>>>>>>> + dev_err(&client->dev, "object %s not found\n", obj_name);
>>>>>>> + return -ENODEV;
>>>>>>> + }
>>>>>>> +
>>>>>>> + cpm = buffer.pointer;
>>>>>>> + for (i = 0; i < cpm->package.count && i < count; ++i) {
>>>>>>> + union acpi_object *elem;
>>>>>>> + elem = &(cpm->package.elements[i]);
>>>>>>> + vals[i] = elem->integer.value;
>>>>>>> + }
>>>>>>> +
>>>>>>> + kfree(buffer.pointer);
>>>>>>> +
>>>>>>> + return cpm->package.count;
>>>>>>> +}
>>>>>>> +
>>>>>>> +/**
>>>>>>> + * cm3218x_reg_init() - Initialize CM3218x registers
>>>>>>> + * @cm3218x: pointer of struct cm3218x.
>>>>>>> + *
>>>>>>> + * Initialize CM3218x ambient light sensor register to default
>>>>> values.
>>>>>>> + *
>>>>>>> +  Return: 0 for success; otherwise for error code.
>>>>>>> + */
>>>>>>> +static int cm3218x_reg_init(struct cm3218x_chip *chip)
>>>>>>> +{
>>>>>>> + struct i2c_client *client = chip->client;
>>>>>>> + int i;
>>>>>>> + s32 ret;
>>>>>>> + int cpm_elem_count;
>>>>>>> + u64 cpm_elems[20];
>>>>>>> + struct cmdev *cmdev;
>>>>>>> +
>>>>>>> + /* Default device */
>>>>>>> + chip->cmdev = &cm3218;
>>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD] = CM3218x_CMD_DEFAULT;
>>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_WH] = CM3218x_WH_DEFAULT;
>>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_WL] = CM3218x_WL_DEFAULT;
>>>>>>> +
>>>>>>> + /* Disable interrupt */
>>>>>>> + cm3218x_interrupt_config(chip, 0);
>>>>>>> +
>>>>>>> + /* Disable Test Mode */
>>>>>>> + i2c_smbus_write_word_data(client, CM3218x_REG_ADDR_TEST,
>>> 0x0000);
>>>>>>> +
>>>>>>> + /* Disable device */
>>>>>>> + i2c_smbus_write_word_data(client, CM3218x_REG_ADDR_CMD,
>>>>>>> + CM3218x_CMD_ALS_DISABLE);
>>>>>>> +
>>>>>>> + /* Identify device */
>>>>>>> + ret = i2c_smbus_read_word_data(client, CM3218x_REG_ADDR_ID);
>>>>>>> + if (ret < 0)
>>>>>>> + return ret;
>>>>>>> + switch (ret & 0xFF) {
>>>>>>> + case 0x18:
>>>>>>> + cmdev = chip->cmdev = &cm3218;
>>>>>>> + if (ret & 0x0800)
>>>>>>> + cmdev->int_type = INT_TYPE_I2C;
>>>>>>> + else
>>>>>>> + cmdev->int_type = INT_TYPE_SMBUS;
>>>>>>> + break;
>>>>>>> + case 0x81:
>>>>>>> + cmdev = chip->cmdev = &cm32181;
>>>>>>> + break;
>>>>>>> + case 0x82:
>>>>>>> + cmdev = chip->cmdev = &cm32182;
>>>>>>> + break;
>>>>>>> + default:
>>>>>>> + return -ENODEV;
>>>>>>> + }
>>>>>>> +
>>>>>>> + if (ACPI_HANDLE(&client->dev)) {
>>>>>>> + /* Load from ACPI */
>>>>>>> + cpm_elem_count = cm3218x_acpi_get_cpm_info(client, "CPM0",
>>>>>>> + ARRAY_SIZE(cpm_elems),
>>>>>>> + cpm_elems);
>>>>>>> + if (cpm_elem_count > 0) {
>>>>>>> + int header_num = 3;
>>>>>>> + int reg_num = cpm_elem_count - header_num;
>>>>>>> +
>>>>>>> + cmdev->regs_bmp = cpm_elems[2];
>>>>>>> + for (i = 0; i < reg_num; i++)
>>>>>>> + if (cmdev->regs_bmp & (1<<i))
>>>>>>> + chip->conf_regs[i] =
>>>>>>> + cpm_elems[header_num+i];
>>>>>>> + }
>>>>>>> +
>>>>>>> + cpm_elem_count = cm3218x_acpi_get_cpm_info(client, "CPM1",
>>>>>>> + ARRAY_SIZE(cpm_elems),
>>>>>>> + cpm_elems);
>>>>>>> + if (cpm_elem_count > 0) {
>>>>>>> + cmdev->mlux_per_bit = (int)cpm_elems[0] / 100;
>>>>>>> + cmdev->calibscale = (int)cpm_elems[1];
>>>>>>> + }
>>>>>>> + }
>>>>>>> +
>>>>>>> + /* Force to disable interrupt */
>>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD] &=
>>> ~CM3218x_CMD_ALS_INT_EN;
>>>>>>> +
>>>>>>> + /* Initialize registers*/
>>>>>> whitespace
>>>>>>
>>>>>>> + for (i = 0; i < CM3218x_CONF_REG_NUM; i++) {
>>>>>>> + if (cmdev->regs_bmp & (1<<i)) {
>>>>>>> + ret = i2c_smbus_write_word_data(client, i,
>>>>>>> + chip->conf_regs[i]);
>>>>>>> + if (ret < 0)
>>>>>>> + return ret;
>>>>>>> + }
>>>>>>> + }
>>>>>>> +
>>>>>>> + return 0;
>>>>>>> +}
>>>>>>> +
>>>>>>> +/**
>>>>>>> + *  cm3218x_read_als_it() - Get sensor integration time (ms)
>>>>>>> + *  @cm3218x: pointer of struct cm3218x
>>>>>>> + *  @val2: pointer of int to load the als_it value.
>>>>>>> + *
>>>>>>> + *  Report the current integartion time by millisecond.
>>>>>> integration time in milliseconds
>>>>>>
>>>>>>> + *
>>>>>>> + *  Return: IIO_VAL_INT_PLUS_MICRO for success, otherwise
>>> -EINVAL.
>>>>>>> + */
>>>>>>> +static int cm3218x_read_als_it(struct cm3218x_chip *chip, int
>>>>> *val2)
>>>>>>> +{
>>>>>>> + struct cmdev *cmdev = chip->cmdev;
>>>>>>> + u16 als_it;
>>>>>>> + int i;
>>>>>>> +
>>>>>>> + als_it = chip->conf_regs[CM3218x_REG_ADDR_CMD];
>>>>>>> + als_it &= CM3218x_CMD_ALS_IT_MASK;
>>>>>>> + als_it >>= CM3218x_CMD_ALS_IT_SHIFT;
>>>>>>> + for (i = 0; i < cmdev->num_als_it; i++) {
>>>>>>> + if (als_it == cmdev->als_it_bits[i]) {
>>>>>>> + *val2 = cmdev->als_it_values[i];
>>>>>>> + return IIO_VAL_INT_PLUS_MICRO;
>>>>>>> + }
>>>>>>> + }
>>>>>>> +
>>>>>>> + return -EINVAL;
>>>>>>> +}
>>>>>>> +
>>>>>>> +/**
>>>>>>> + * cm3218x_write_als_it() - Write sensor integration time
>>>>>>> + * @cm3218x: pointer of struct cm3218x.
>>>>>>> + * @val: integration time by millisecond.
>>>>>>> + *
>>>>>>> + * Convert integration time (ms) to sensor value.
>>>>>>> + *
>>>>>>> + * Return: i2c_smbus_write_word_data command return value.
>>>>>>> + */
>>>>>>> +static int cm3218x_write_als_it(struct cm3218x_chip *chip, int
>>> val)
>>>>>>> +{
>>>>>>> + struct i2c_client *client = chip->client;
>>>>>>> + struct cmdev *cmdev = chip->cmdev;
>>>>>>> + u16 als_it;
>>>>>>> + int ret, i;
>>>>>>> +
>>>>>>> + for (i = 0; i < cmdev->num_als_it; i++)
>>>>>>> + if (val <= cmdev->als_it_values[i])
>>>>>>> + break;
>>>>>>> + if (i >= cmdev->num_als_it)
>>>>>>> + i = cmdev->num_als_it - 1;
>>>>>>> +
>>>>>>> + als_it = cmdev->als_it_bits[i];
>>>>>>> + als_it <<= CM3218x_CMD_ALS_IT_SHIFT;
>>>>>>> +
>>>>>>> + mutex_lock(&chip->lock);
>>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD] &=
>>>>>>> + ~CM3218x_CMD_ALS_IT_MASK;
>>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD] |=
>>>>>>> + als_it;
>>>>>>> + ret = i2c_smbus_write_word_data(client, CM3218x_REG_ADDR_CMD,
>>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD]);
>>>>>>> + mutex_unlock(&chip->lock);
>>>>>>> +
>>>>>>> + return ret;
>>>>>>> +}
>>>>>>> +
>>>>>>> +/**
>>>>>>> + * cm3218x_get_lux() - report current lux value
>>>>>>> + * @cm3218x: pointer of struct cm3218x.
>>>>>>> + *
>>>>>>> + * Convert sensor raw data to lux.  It depends on integration
>>>>>>> + * time and claibscale variable.
>>>>>> calibscale
>>>>>>
>>>>>>> + *
>>>>>>> + * Return: Positive value is lux, otherwise is error code.
>>>>>>> + */
>>>>>>> +static int cm3218x_get_lux(struct cm3218x_chip *chip)
>>>>>>> +{
>>>>>>> + struct i2c_client *client = chip->client;
>>>>>>> + struct cmdev *cmdev = chip->cmdev;
>>>>>>> + int ret;
>>>>>>> + int als_it;
>>>>>>> + int lux;
>>>>>> lux variable is not needed
>>>>>>
>>>>>>> + u64 tmp;
>>>>>>> +
>>>>>>> + /* Calculate mlux per bit based on als_it */
>>>>>>> + ret = cm3218x_read_als_it(chip, &als_it);
>>>>>>> + if (ret < 0)
>>>>>>> + return -EINVAL;
>>>>>>> + tmp = (__force u64)cmdev->mlux_per_bit;
>>>>>>> + tmp *= cmdev->mlux_per_bit_base_it;
>>>>>>> + tmp = div_u64(tmp, als_it);
>>>>>>> +
>>>>>>> + /* Get als_raw */
>>>>>>> + if (!(chip->conf_regs[CM3218x_REG_ADDR_CMD] &
>>>>> CM3218x_CMD_ALS_INT_EN))
>>>>>>> + chip->als_raw = i2c_smbus_read_word_data(
>>>>>>> + client,
>>>>>>> + CM3218x_REG_ADDR_ALS);
>>>>>>> + if (chip->als_raw < 0)
>>>>>>> + return chip->als_raw;
>>>>>>> +
>>>>>>> + tmp *= chip->als_raw;
>>>>>>> + tmp *= cmdev->calibscale;
>>>>>>> + tmp = div_u64(tmp, CM3218x_CALIBSCALE_RESOLUTION);
>>>>>>> + tmp = div_u64(tmp, MLUX_PER_LUX);
>>>>>>> +
>>>>>>> + if (tmp > 0xFFFF)
>>>>>>> + tmp = 0xFFFF;
>>>>>>> +
>>>>>>> + lux = (int)tmp;
>>>>>>> + return lux;
>>>>>>> +}
>>>>>>> +
>>>>>>> +static int cm3218x_read_raw(struct iio_dev *indio_dev,
>>>>>>> + struct iio_chan_spec const *chan,
>>>>>>> + int *val, int *val2, long mask)
>>>>>>> +{
>>>>>>> + struct cm3218x_chip *chip = iio_priv(indio_dev);
>>>>>>> + struct cmdev *cmdev = chip->cmdev;
>>>>>>> + int ret;
>>>>>>> +
>>>>>>> + switch (mask) {
>>>>>>> + case IIO_CHAN_INFO_PROCESSED:
>>>>>>> + ret = cm3218x_get_lux(chip);
>>>>>>> + if (ret < 0)
>>>>>>> + return ret;
>>>>>>> + *val = ret;
>>>>>>> + return IIO_VAL_INT;
>>>>>>> + case IIO_CHAN_INFO_CALIBSCALE:
>>>>>>> + *val = cmdev->calibscale;
>>>>>>> + return IIO_VAL_INT;
>>>>>>> + case IIO_CHAN_INFO_INT_TIME:
>>>>>>> + *val = 0;
>>>>>>> + ret = cm3218x_read_als_it(chip, val2);
>>>>>>> + return ret;
>>>>>>> + }
>>>>>>> +
>>>>>>> + return -EINVAL;
>>>>>>> +}
>>>>>>> +
>>>>>>> +static int cm3218x_write_raw(struct iio_dev *indio_dev,
>>>>>>> + struct iio_chan_spec const *chan,
>>>>>>> + int val, int val2, long mask)
>>>>>>> +{
>>>>>>> + struct cm3218x_chip *chip = iio_priv(indio_dev);
>>>>>>> + struct cmdev *cmdev = chip->cmdev;
>>>>>>> + int ret;
>>>>>> ret not needed
>>>>>>
>>>>>>> +
>>>>>>> + switch (mask) {
>>>>>>> + case IIO_CHAN_INFO_CALIBSCALE:
>>>>>>> + cmdev->calibscale = val;
>>>>>>> + return val;
>>>>>>> + case IIO_CHAN_INFO_INT_TIME:
>>>>>> val==0 could be checked here
>>>>>>
>>>>>>> + ret = cm3218x_write_als_it(chip, val2);
>>>>>>> + return ret;
>>>>>>> + }
>>>>>>> +
>>>>>>> + return -EINVAL;
>>>>>>> +}
>>>>>>> +
>>>>>>> +/**
>>>>>>> + * cm3218x_get_it_available() - Get available ALS IT value
>>>>>>> + * @dev: pointer of struct device.
>>>>>>> + * @attr: pointer of struct device_attribute.
>>>>>>> + * @buf: pointer of return string buffer.
>>>>>>> + *
>>>>>>> + * Display the available integration time values by millisecond.
>>>>>>> + *
>>>>>>> + * Return: string length.
>>>>>>> + */
>>>>>>> +static ssize_t cm3218x_get_it_available(struct device *dev,
>>>>>>> + struct device_attribute *attr, char *buf)
>>>>>>> +{
>>>>>>> + struct cm3218x_chip *chip = iio_priv(dev_to_iio_dev(dev));
>>>>>>> + struct cmdev *cmdev = chip->cmdev;
>>>>>>> + int i, len;
>>>>>>> +
>>>>>>> + for (i = 0, len = 0; i < cmdev->num_als_it; i++)
>>>>>>> + len += sprintf(buf + len, "0.%06u ", cmdev->als_it_values[i]);
>>>>>> scnprintf(buf+len, PAGESIZE-len, ...) could be used
>>>>>>
>>>>>>> + return len + sprintf(buf + len, "\n");
>>>>>>> +}
>>>>>>> +
>>>>>>> +/**
>>>>>>> + * cm3218x_threshold_update() - Update the threshold registers.
>>>>>>> + * @dev: pointer of struct cm3218x_chip.
>>>>>> @chip
>>>>>>
>>>>>>> + * @percent: +/- percent.
>>>>>>> + *
>>>>>>> + * Based on the current ALS value, tupdate the hi and low
>>> threshold
>>>>>>> registers.
>>>>>>> + *
>>>>>>> + * Return: string length.
>>>>>> definitely not the string length
>>>>>>
>>>>>>> + */
>>>>>>> +static int cm3218x_threshold_update(struct cm3218x_chip *chip,
>>> int
>>>>>>> percent)
>>>>>>> +{
>>>>>>> + struct i2c_client *client = chip->client;
>>>>>>> + int ret;
>>>>>>> + int wh, wl;
>>>>>>> +
>>>>>>> + ret = chip->als_raw = i2c_smbus_read_word_data(client,
>>>>>>> + CM3218x_REG_ADDR_ALS);
>>>>>>> + if (ret < 0)
>>>>>>> + return ret;
>>>>>>> +
>>>>>>> + wh = wl = ret;
>>>>>>> + ret *= percent;
>>>>>>> + ret /= 100;
>>>>>>> + if (ret < 1)
>>>>>>> + ret = 1;
>>>>>>> + wh += ret;
>>>>>>> + wl -= ret;
>>>>>>> + if (wh > 65535)
>>>>>>> + wh = 65535;
>>>>>>> + if (wl < 0)
>>>>>>> + wl = 0;
>>>>>>> +
>>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_WH] = wh;
>>>>>>> + ret = i2c_smbus_write_word_data(
>>>>>>> + client,
>>>>>>> + CM3218x_REG_ADDR_WH,
>>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_WH]);
>>>>>>> + if (ret < 0)
>>>>>>> + return ret;
>>>>>>> +
>>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_WL] = wl;
>>>>>>> + ret = i2c_smbus_write_word_data(
>>>>>>> + client,
>>>>>>> + CM3218x_REG_ADDR_WL,
>>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_WL]);
>>>>>> just
>>>>>> return ret;
>>>>>>
>>>>>>> + if (ret < 0)
>>>>>>> + return ret;
>>>>>>> +
>>>>>>> + return 0;
>>>>>>> +}
>>>>>>> +
>>>>>>> +/**
>>>>>>> + * cm3218x_event_handler() - Interrupt handling routine.
>>>>>>> + * @irq: irq number.
>>>>>>> + * @private: pointer of void.
>>>>>>> + *
>>>>>>> + * Clean interrupt and reset threshold registers.
>>>>>>> + *
>>>>>>> + * Return: string length.
>>>>>>
>>>>>>> + */
>>>>>>> +static irqreturn_t cm3218x_event_handler(int irq, void *private)
>>>>>>> +{
>>>>>>> + struct iio_dev *dev_info = private;
>>>>>>> + struct cm3218x_chip *chip = iio_priv(dev_info);
>>>>>>> + int ret;
>>>>>>> +
>>>>>>> + mutex_lock(&chip->lock);
>>>>>>> +
>>>>>>> + /* Disable interrupt */
>>>>>>> + ret = cm3218x_interrupt_config(chip, 0);
>>>>>>> + if (ret < 0)
>>>>>>> + goto error_handler_unlock;
>>>>>>> +
>>>>>>> + /* Update Hi/Lo windows */
>>>>>>> + ret = cm3218x_threshold_update(chip, CM3218x_THRESHOLD_PERCENT);
>>>>>>> + if (ret < 0)
>>>>>>> + goto error_handler_unlock;
>>>>>>> +
>>>>>>> + /* Enable interrupt */
>>>>>>> + ret = cm3218x_interrupt_config(chip, 1);
>>>>>>> + if (ret < 0)
>>>>>>> + goto error_handler_unlock;
>>>>>>> +
>>>>>>> + mutex_unlock(&chip->lock);
>>>>>>> +
>>>>>>> + return IRQ_HANDLED;
>>>>>>> +
>>>>>>> +error_handler_unlock:
>>>>>>> + mutex_unlock(&chip->lock);
>>>>>>> + return IRQ_NONE;
>>>>>> I think it should be IRQ_HANDLED always
>>>>>> there is no check if the interrupt indeed stems from this device
>>>>>>
>>>>>>> +}
>>>>>>> +
>>>>>>> +static const struct iio_chan_spec cm3218x_channels[] = {
>>>>>>> + {
>>>>>>> + .type = IIO_LIGHT,
>>>>>>> + .info_mask_separate =
>>>>>>> + BIT(IIO_CHAN_INFO_PROCESSED) |
>>>>>>> + BIT(IIO_CHAN_INFO_CALIBSCALE) |
>>>>>>> + BIT(IIO_CHAN_INFO_INT_TIME),
>>>>>>> + }
>>>>>>> +};
>>>>>>> +
>>>>>>> +static IIO_DEVICE_ATTR(in_illuminance_integration_time_available,
>>>>>>> + S_IRUGO, cm3218x_get_it_available, NULL, 0);
>>>>>>> +
>>>>>>> +static struct attribute *cm3218x_attributes[] = {
>>>>>>> +
>>> &iio_dev_attr_in_illuminance_integration_time_available.dev_attr.attr,
>>>>>>> + NULL,
>>>>>>> +};
>>>>>>> +
>>>>>>> +static const struct attribute_group cm3218x_attribute_group = {
>>>>>>> + .attrs = cm3218x_attributes
>>>>>>> +};
>>>>>>> +
>>>>>>> +static const struct iio_info cm3218x_info = {
>>>>>>> + .driver_module = THIS_MODULE,
>>>>>>> + .read_raw = &cm3218x_read_raw,
>>>>>>> + .write_raw = &cm3218x_write_raw,
>>>>>>> + .attrs = &cm3218x_attribute_group,
>>>>>>> +};
>>>>>>> +
>>>>>>> +static int cm3218x_probe(struct i2c_client *client,
>>>>>>> + const struct i2c_device_id *id)
>>>>>>> +{
>>>>>>> + struct cm3218x_chip *chip;
>>>>>>> + struct iio_dev *indio_dev;
>>>>>>> + int ret;
>>>>>>> +
>>>>>>> + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
>>>>>>> + if (!indio_dev) {
>>>>>>> + dev_err(&client->dev, "devm_iio_device_alloc failed\n");
>>>>>>> + return -ENOMEM;
>>>>>>> + }
>>>>>>> +
>>>>>>> + chip = iio_priv(indio_dev);
>>>>>>> + i2c_set_clientdata(client, indio_dev);
>>>>>>> + chip->client = client;
>>>>>>> +
>>>>>>> + mutex_init(&chip->lock);
>>>>>>> + indio_dev->dev.parent = &client->dev;
>>>>>>> + indio_dev->channels = cm3218x_channels;
>>>>>>> + indio_dev->num_channels = ARRAY_SIZE(cm3218x_channels);
>>>>>>> + indio_dev->info = &cm3218x_info;
>>>>>>> + if (id && id->name)
>>>>>>> + indio_dev->name = id->name;
>>>>>>> + else
>>>>>>> + indio_dev->name = (char *)dev_name(&client->dev);
>>>>>>> + indio_dev->modes = INDIO_DIRECT_MODE;
>>>>>>> +
>>>>>>> + ret = cm3218x_reg_init(chip);
>>>>>>> + if (ret) {
>>>>>>> + dev_err(&client->dev,
>>>>>>> + "%s: register init failed\n",
>>>>>>> + __func__);
>>>>>>> + return ret;
>>>>>>> + }
>>>>>>> +
>>>>>>> + if (client->irq) {
>>>>>>> + ret = request_threaded_irq(client->irq,
>>>>>>> + NULL,
>>>>>>> + cm3218x_event_handler,
>>>>>>> + IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
>>>>>>> + "cm3218x_event",
>>>>>>> + indio_dev);
>>>>>>> +
>>>>>>> + if (ret < 0) {
>>>>>>> + dev_err(&client->dev, "irq request error %d\n",
>>>>>>> + -ret);
>>>>>>> + goto error_disable_int;
>>>>>>> + }
>>>>>>> + }
>>>>>>> +
>>>>>>> + ret = iio_device_register(indio_dev);
>>>>>>> + if (ret < 0) {
>>>>>>> + dev_err(&client->dev,
>>>>>>> + "%s: regist device failed\n",
>>>>>>> + __func__);
>>>>>>> + goto error_free_irq;
>>>>>>> + }
>>>>>>> +
>>>>>>> + if (client->irq) {
>>>>>>> + ret = cm3218x_threshold_update(chip, CM3218x_THRESHOLD_PERCENT);
>>>>>>> + if (ret < 0)
>>>>>>> + goto error_free_irq;
>>>>>>> +
>>>>>>> + ret = cm3218x_interrupt_config(chip, 1);
>>>>>>> + if (ret < 0)
>>>>>>> + goto error_free_irq;
>>>>>>> + }
>>>>>>> +
>>>>>>> + return 0;
>>>>>>> +
>>>>>>> +error_free_irq:
>>>>>>> + free_irq(client->irq, indio_dev);
>>>>>>> +error_disable_int:
>>>>>>> + cm3218x_interrupt_config(chip, 0);
>>>>>>> + return ret;
>>>>>>> +}
>>>>>>> +
>>>>>>> +static int cm3218x_remove(struct i2c_client *client)
>>>>>>> +{
>>>>>>> + struct iio_dev *indio_dev = i2c_get_clientdata(client);
>>>>>>> + struct cm3218x_chip *chip = iio_priv(indio_dev);
>>>>>>> +
>>>>>>> + cm3218x_interrupt_config(chip, 0);
>>>>>>> + if (client->irq)
>>>>>>> + free_irq(client->irq, indio_dev);
>>>>>>> + iio_device_unregister(indio_dev);
>>>>>>> + return 0;
>>>>>>> +}
>>>>>>> +
>>>>>>> +static const struct i2c_device_id cm3218x_id[] = {
>>>>>>> + { "cm3218x", 0},
>>>>>>> + { }
>>>>>>> +};
>>>>>>> +
>>>>>>> +MODULE_DEVICE_TABLE(i2c, cm3218x_id);
>>>>>>> +
>>>>>>> +static const struct of_device_id cm3218x_of_match[] = {
>>>>>>> + { .compatible = "capella,cm3218x" },
>>>>>>> + { }
>>>>>>> +};
>>>>>>> +
>>>>>>> +static const struct acpi_device_id cm3218x_acpi_match[] = {
>>>>>>> + { "CPLM3218", 0},
>>>>>>> + {},
>>>>>>> +};
>>>>>>> +
>>>>>>> +MODULE_DEVICE_TABLE(acpi, cm3218x_acpi_match);
>>>>>>> +
>>>>>>> +static struct i2c_driver cm3218x_driver = {
>>>>>>> + .driver = {
>>>>>>> + .name = "cm3218x",
>>>>>>> + .acpi_match_table = ACPI_PTR(cm3218x_acpi_match),
>>>>>>> + .of_match_table = of_match_ptr(cm3218x_of_match),
>>>>>>> + .owner = THIS_MODULE,
>>>>>>> + },
>>>>>>> + .id_table = cm3218x_id,
>>>>>>> + .probe = cm3218x_probe,
>>>>>>> + .remove = cm3218x_remove,
>>>>>>> +};
>>>>>>> +
>>>>>>> +module_i2c_driver(cm3218x_driver);
>>>>>>> +
>>>>>>> +MODULE_AUTHOR("Kevin Tsai <ktsai-GubuWUlQtMwciDkP5Hr2oA@public.gmane.org>");
>>>>>>> +MODULE_DESCRIPTION("CM3218x ambient light sensor driver");
>>>>>>> +MODULE_LICENSE("GPL");
>>>>>>>
>>>>>> --
>>>>>>
>>>>>> Peter Meerwald
>>>>>> +43-664-2444418 (mobile)
>
> --
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Re: [PATCH V1 1/1] iio: add Capella cm3218x ambient light sensor driver.

[Srinivas Pandruvada]

On 03/22/2014 05:17 AM, Jonathan Cameron wrote:
> On 21/03/14 22:21, Srinivas Pandruvada wrote:
>> On 03/21/2014 03:05 PM, Jonathan Cameron wrote:
>>>
>>> On March 20, 2014 11:19:49 PM GMT+00:00, Srinivas Pandruvada
>>> <srinivas.pandruvada-VuQAYsv1563Yd54FQh9/CA@public.gmane.org> wrote:
>>>> On 03/19/2014 11:54 PM, Jonathan Cameron wrote:
>>>>> On March 20, 2014 12:58:02 AM GMT+00:00, Kevin Tsai
>>>> <ktsai-GubuWUlQtMwciDkP5Hr2oA@public.gmane.org> wrote:
>>>>>> Hi Peter,
>>>>>>
>>>>>> Thanks for your advise.  I'll update my code.
>>>>>>
>>>>>> ACPI is optional.  Most PC manufactory may store the lens factor to
>>>>>> ACPI
>>>>>> table.  But, phone customers like to modify the parameters inside
>>>> code.
>>>>>> CM3218 have two versions.  The old version need to read SMBus ARA
>>>>>> register
>>>>>> to clean interrupt.  That's why I need to change I2C chip address.
>>>>>> Please
>>>>>> guid me if you have a better way to access two addresses.
>>>>> Would the smbus alert infrastructure in drivers/i2ç/i2c-smbus.c help?
>>>> The smbus alert notification are based on the underlying i2c
>>>> controller.
>>>> Not every controller supports. I can see only one controller driver in
>>>> the upstream Linux added this support.
>>> To my mind adding wider support for the alert functionality will be
>>> the way forward.
>>>
>>> Wolfram, any idea why so few bus drivers implement the smbus alert
>>> stuff? I would
>>>   guess you won't be against wider support of this using existing
>>> infrastructure?
>> SMALRT is a physical pin connection. Most of the i2C controlleron X86
>> will have no option to connect
>> SMALRT signal. So may be we need a common API to read instead, to read
>> and get status.
> Unless I am missing something, it's just a shared interrupt really
> common to whatever
> devices are connected to the smbus controller.  If the typical i2c
> controller on x86
> doesn't have an interrupt line (and one isn't provided by some other
> route) then
> the driver as a whole will need polled support.
>
> They will still need a means of resetting the alert line via the ara
> address though
> so we probably need some means of supporting that...  Perhaps the
> approach used
> in this driver is the right way to go, but if it is then it should be
> wrapped
> up in a core function rather than exposing the address switching in the
> driver itself.
>
> Remember there may well be more than one device with smbus alert support
> on the bus.
> The approach here will clear the interrupt on one of them but not
> necessarily this device.
>
> I hate to say it but anyone who uses an smbus alert equipped device
> without actually
> having a shared interrupt line is asking for trouble.  Some devices
> offer an alternative
> means of deasserting the interrupt (max1363) thus allowing use with the
> smbus alert
> address querying, or with a normal interrupt line.  I don't suppose that
> is the case here?
>

I agree, we need to have a mechanism to handle in the core. Otherwise it 
will be issue if multiple clients needs this support.
I think we should introduce a function in the i2c_smbus driver to 
trigger smbus ARA read. This function will read ARA. If ARA read is 
successful, then it will use existing smbus_alert() to notify the i2c 
client driver, who should process. (ARA register read either fails or 
responds with the device address of the alerting device).

Basically this triggers to same as currently ISR
smbalert_irq(int irq, void *d) is doing.


Thanks,
Srinivas





> Jonathan
>>
>> Thanks,
>> Srinivas
>>
>>>> Thanks,
>>>> Srinivas
>>>>
>>>>>> Thanks.
>>>>>>
>>>>>> Kevin Tsai
>>>>>> 03/19/14
>>>>>>
>>>>>> ----- Original Message -----
>>>>>> From: "Peter Meerwald" <pmeerw-jW+XmwGofnusTnJN9+BGXg@public.gmane.org>
>>>>>> To: "Kevin Tsai" <ktsai-GubuWUlQtMwciDkP5Hr2oA@public.gmane.org>
>>>>>> Cc: "Jonathan Cameron" <jic23-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>;
>>>> <linux-iio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
>>>>>> Sent: Wednesday, March 19, 2014 11:07
>>>>>> Subject: Re: [PATCH V1 1/1] iio: add Capella cm3218x ambient light
>>>>>> sensor
>>>>>> driver.
>>>>>>
>>>>>>
>>>>>>>> Add Capella Microsystem CM3218x family Ambient Light Sensor IIO
>>>>>> driver.
>>>>>>>> This driver will convert raw data to lux value.  Default
>>>> parameters
>>>>>> are
>>>>>>>> for reference only.  It will detect ACPI table to load per-system
>>>>>>>> manufacturing
>>>>>>>> parameters.
>>>>>>> nitpicking below
>>>>>>>
>>>>>>>> ---
>>>>>>>>    .../devicetree/bindings/i2c/trivial-devices.txt    |   1 +
>>>>>>>>    drivers/iio/light/Kconfig                          |  11 +
>>>>>>>>    drivers/iio/light/Makefile                         |   1 +
>>>>>>>>    drivers/iio/light/cm3218x.c                        | 769
>>>>>>>> +++++++++++++++++++++
>>>>>>>>    4 files changed, 782 insertions(+)
>>>>>>>>    create mode 100644 drivers/iio/light/cm3218x.c
>>>>>>>>
>>>>>>>> diff --git
>>>>>> a/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>>>>>>>> b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>>>>>>>> index 1a1ac2e..29e7eae 100644
>>>>>>>> --- a/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>>>>>>>> +++ b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>>>>>>>> @@ -17,6 +17,7 @@ at,24c08 i2c serial eeprom  (24cxx)
>>>>>>>>    atmel,24c02 i2c serial eeprom  (24cxx)
>>>>>>>>    atmel,at97sc3204t i2c trusted platform module (TPM)
>>>>>>>>    capella,cm32181 CM32181: Ambient Light Sensor
>>>>>>>> +capella,cm3218x CM3218x: Ambient Light Sensor
>>>>>>>>    catalyst,24c32 i2c serial eeprom
>>>>>>>>    dallas,ds1307 64 x 8, Serial, I2C Real-Time Clock
>>>>>>>>    dallas,ds1338 I2C RTC with 56-Byte NV RAM
>>>>>>>> diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
>>>>>>>> index d12b2a0..45a22a6 100644
>>>>>>>> --- a/drivers/iio/light/Kconfig
>>>>>>>> +++ b/drivers/iio/light/Kconfig
>>>>>>>> @@ -38,6 +38,17 @@ config CM32181
>>>>>>>>    To compile this driver as a module, choose M here:
>>>>>>>>    the module will be called cm32181.
>>>>>>>>
>>>>>>>> +config CM3218X
>>>>>>>> + depends on I2C
>>>>>>> is there an ACPI dependency?
>>>>>>>
>>>>>>>> + tristate "CM3218x driver"
>>>>>>>> + help
>>>>>>>> + Say Y here if you use cm3218x.
>>>>>>>> + This option enables ambient light sensor using
>>>>>>>> + Capella cm3218x device driver.
>>>>>>>> +
>>>>>>>> + To compile this driver as a module, choose M here:
>>>>>>>> + the module will be called cm3218x.
>>>>>>>> +
>>>>>>>>    config CM36651
>>>>>>>>    depends on I2C
>>>>>>>>    tristate "CM36651 driver"
>>>>>>>> diff --git a/drivers/iio/light/Makefile
>>>> b/drivers/iio/light/Makefile
>>>>>>>> index 60e35ac..a506c23 100644
>>>>>>>> --- a/drivers/iio/light/Makefile
>>>>>>>> +++ b/drivers/iio/light/Makefile
>>>>>>>> @@ -6,6 +6,7 @@
>>>>>>>>    obj-$(CONFIG_ADJD_S311) += adjd_s311.o
>>>>>>>>    obj-$(CONFIG_APDS9300) += apds9300.o
>>>>>>>>    obj-$(CONFIG_CM32181) += cm32181.o
>>>>>>>> +obj-$(CONFIG_CM3218X) += cm3218x.o
>>>>>>>>    obj-$(CONFIG_CM36651) += cm36651.o
>>>>>>>>    obj-$(CONFIG_GP2AP020A00F) += gp2ap020a00f.o
>>>>>>>>    obj-$(CONFIG_HID_SENSOR_ALS) += hid-sensor-als.o
>>>>>>>> diff --git a/drivers/iio/light/cm3218x.c
>>>>>> b/drivers/iio/light/cm3218x.c
>>>>>>>> new file mode 100644
>>>>>>>> index 0000000..e422f68
>>>>>>>> --- /dev/null
>>>>>>>> +++ b/drivers/iio/light/cm3218x.c
>>>>>>>> @@ -0,0 +1,769 @@
>>>>>>>> +/*
>>>>>>>> + * Copyright (C) 2014 Capella Microsystems Inc.
>>>>>>>> + * Author: Kevin Tsai <ktsai-GubuWUlQtMwciDkP5Hr2oA@public.gmane.org>
>>>>>>>> + *
>>>>>>>> + * This program is free software; you can redistribute it and/or
>>>>>> modify
>>>>>>>> it
>>>>>>>> + * under the terms of the GNU General Public License version 2,
>>>> as
>>>>>>>> published
>>>>>>>> + * by the Free Software Foundation.
>>>>>>>> + *
>>>>>>>> + * Special thanks Srinivas Pandruvada
>>>>>>>> <srinivas.pandruvada-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
>>>>>>>> + * help to add ACPI support.
>>>>>>>> + *
>>>>>>>> + */
>>>>>>>> +
>>>>>>>> +#include <linux/delay.h>
>>>>>>>> +#include <linux/err.h>
>>>>>>>> +#include <linux/i2c.h>
>>>>>>>> +#include <linux/mutex.h>
>>>>>>>> +#include <linux/module.h>
>>>>>>>> +#include <linux/interrupt.h>
>>>>>>>> +#include <linux/regulator/consumer.h>
>>>>>>>> +#include <linux/iio/iio.h>
>>>>>>>> +#include <linux/iio/sysfs.h>
>>>>>>>> +#include <linux/iio/events.h>
>>>>>>>> +#include <linux/init.h>
>>>>>>>> +#include <linux/acpi.h>
>>>>>>>> +
>>>>>>>> +/* Registers Address */
>>>>>>>> +#define CM3218x_REG_ADDR_CMD 0x00
>>>>>>>> +#define CM3218x_REG_ADDR_WH 0x01
>>>>>>>> +#define CM3218x_REG_ADDR_WL 0x02
>>>>>>>> +#define CM3218x_REG_ADDR_TEST 0x03
>>>>>>> inconsistent whitespace allover
>>>>>>>
>>>>>>>> +#define CM3218x_REG_ADDR_ALS 0x04
>>>>>>>> +#define CM3218x_REG_ADDR_STATUS 0x06
>>>>>>>> +#define CM3218x_REG_ADDR_ID 0x07
>>>>>>>> +
>>>>>>>> +/* Number of Configurable Registers */
>>>>>>>> +#define CM3218x_CONF_REG_NUM 16
>>>>>>>> +
>>>>>>>> +/* CMD register */
>>>>>>>> +#define CM3218x_CMD_ALS_DISABLE 0x01
>>>>>>>> +#define CM3218x_CMD_ALS_INT_EN 0x02
>>>>>>>> +#define CM3218x_CMD_ALS_THRES_WINDOW 0x04
>>>>>>>> +
>>>>>>>> +#define CM3218x_CMD_ALS_PERS_SHIFT 4
>>>>>>>> +#define CM3218x_CMD_ALS_PERS_MASK (0x03 <<
>>>>>> CM3218x_CMD_ALS_PERS_SHIFT)
>>>>>>>> +#define CM3218x_CMD_ALS_PERS_DEFAULT (0x01 <<
>>>>>>>> CM3218x_CMD_ALS_PERS_SHIFT)
>>>>>>>> +
>>>>>>>> +#define CM3218x_CMD_ALS_IT_SHIFT 6
>>>>>>>> +#define CM3218x_CMD_ALS_IT_MASK (0x0F <<
>>>> CM3218x_CMD_ALS_IT_SHIFT)
>>>>>>>> +#define CM3218x_CMD_ALS_IT_DEFAULT (0x01 <<
>>>>>> CM3218x_CMD_ALS_IT_SHIFT)
>>>>>>>> +
>>>>>>>> +#define CM3218x_CMD_ALS_HS_SHIFT 11
>>>>>>>> +#define CM3218x_CMD_ALS_HS_MASK (0x01 <<
>>>> CM3218x_CMD_ALS_HS_SHIFT)
>>>>>>>> +#define CM3218x_CMD_ALS_HS_DEFAULT (0x00 <<
>>>>>> CM3218x_CMD_ALS_HS_SHIFT)
>>>>>>>> +
>>>>>>>> +#define CM3218x_CMD_DEFAULT (CM3218x_CMD_ALS_THRES_WINDOW |\
>>>>>>>> + CM3218x_CMD_ALS_PERS_DEFAULT |\
>>>>>>>> + CM3218x_CMD_ALS_IT_DEFAULT |\
>>>>>>>> + CM3218x_CMD_ALS_HS_DEFAULT)
>>>>>>>> +
>>>>>>>> +#define CM3218x_WH_DEFAULT 0xFFFF
>>>>>>>> +#define CM3218x_WL_DEFAULT 0x0000
>>>>>>>> +
>>>>>>>> +#define CM3218x_CALIBSCALE_DEFAULT 100000
>>>>>>>> +#define CM3218x_CALIBSCALE_RESOLUTION 100000
>>>>>>>> +#define MLUX_PER_LUX 1000
>>>>>>> CM3218x prefix missing
>>>>>>>
>>>>>>> the lowercase x in macros is a bit weird for my taste
>>>>>>>
>>>>>>>> +#define CM3218x_THRESHOLD_PERCENT 10 /* 10 percent */
>>>>>>>> +
>>>>>>>> +/* CM3218 Family */
>>>>>>>> +#define CM3218_MLUX_PER_BIT_DEFAULT 5 /* Depend on system */
>>>>>>>> +#define CM3218_MLUX_PER_BIT_BASE_IT 800000
>>>>>>>> +static int CM3218_als_it_bits[] = {0, 1, 2, 3};
>>>>>>>> +static int CM3218_als_it_values[] = {100000, 200000, 400000,
>>>>>> 800000};
>>>>>>> const missing
>>>>>>>
>>>>>>>> +
>>>>>>>> +/* CM32181 Family */
>>>>>>>> +#define CM32181_MLUX_PER_BIT_DEFAULT 5
>>>>>>>> +#define CM32181_MLUX_PER_BIT_BASE_IT 800000
>>>>>>>> +static int CM32181_als_it_bits[] = {12, 8, 0, 1, 2, 3};
>>>>>>>> +static int CM32181_als_it_values[] = {
>>>>>>>> + 25000, 50000, 100000, 200000, 400000, 800000};
>>>>>>> const missing
>>>>>>>
>>>>>>>> +
>>>>>>>> +/* CM32182 Family */
>>>>>>>> +#define CM32182_MLUX_PER_BIT_DEFAULT 5
>>>>>>>> +#define CM32182_MLUX_PER_BIT_BASE_IT 800000
>>>>>>>> +static int CM32182_als_it_bits[] = {12, 8, 0, 1, 2, 3};
>>>>>>>> +static int CM32182_als_it_values[] = {
>>>>>>>> + 25000, 50000, 100000, 200000, 400000, 800000};
>>>>>>> const missing
>>>>>>>
>>>>>>> these definitions are largely identical and could be dropped; they
>>>>>> are
>>>>>>> only used to fill device-specific tables below; why have a separate
>>>>>>> define here?
>>>>>>>
>>>>>>>> +
>>>>>>>> +struct cmdev {
>>>>>>> prefix?
>>>>>>>
>>>>>>>> + u32 family_id;
>>>>>>>> + int int_type;
>>>>>>>> +#define INT_TYPE_SMBUS 0
>>>>>>>> +#define INT_TYPE_I2C 1
>>>>>>> prefix?
>>>>>>>
>>>>>>>> + int regs_bmp;
>>>>>>>> + int calibscale;
>>>>>>>> + int mlux_per_bit;
>>>>>>>> + int mlux_per_bit_base_it;
>>>>>>>> + int *als_it_bits;
>>>>>>>> + int *als_it_values;
>>>>>>>> + int num_als_it;
>>>>>>>> +};
>>>>>>>> +
>>>>>>>> +static struct cmdev cm3218 = {
>>>>>>>> + 3218, INT_TYPE_SMBUS, 0x0F, CM3218x_CALIBSCALE_DEFAULT,
>>>>>>>> + CM3218_MLUX_PER_BIT_DEFAULT, CM3218_MLUX_PER_BIT_BASE_IT,
>>>>>>>> + CM3218_als_it_bits, CM3218_als_it_values,
>>>>>>>> + ARRAY_SIZE(CM3218_als_it_bits)};
>>>>>>>> +
>>>>>>>> +static struct cmdev cm32181 = {
>>>>>>>> + 32181, INT_TYPE_I2C, 0x0F, CM3218x_CALIBSCALE_DEFAULT,
>>>>>>>> + CM32181_MLUX_PER_BIT_DEFAULT, CM32181_MLUX_PER_BIT_BASE_IT,
>>>>>>>> + CM32181_als_it_bits, CM32181_als_it_values,
>>>>>>>> + ARRAY_SIZE(CM32181_als_it_bits)};
>>>>>>>> +
>>>>>>>> +static struct cmdev cm32182 = {
>>>>>>>> + 32182, INT_TYPE_I2C, 0x0F, CM3218x_CALIBSCALE_DEFAULT,
>>>>>>>> + CM32182_MLUX_PER_BIT_DEFAULT, CM32182_MLUX_PER_BIT_BASE_IT,
>>>>>>>> + CM32182_als_it_bits, CM32182_als_it_values,
>>>>>>>> + ARRAY_SIZE(CM32182_als_it_bits)};
>>>>>>>> +
>>>>>>>> +struct cm3218x_chip {
>>>>>>>> + struct i2c_client *client;
>>>>>>>> + struct cmdev *cmdev;
>>>>>>>> + struct mutex lock;
>>>>>>>> + u16 conf_regs[CM3218x_CONF_REG_NUM];
>>>>>>>> + int als_raw;
>>>>>>>> +};
>>>>>>>> +
>>>>>>>> +static int cm3218x_get_lux(struct cm3218x_chip *chip);
>>>>>>>> +static int cm3218x_threshold_update(struct cm3218x_chip *chip,
>>>> int
>>>>>>>> percent);
>>>>>>>> +static int cm3218x_read_als_it(struct cm3218x_chip *chip, int
>>>>>> *val2);
>>>>>>>> +
>>>>>>>> +/**
>>>>>>>> + * cm3218x_read_ara() - Read ARA register
>>>>>>>> + * @cm3218x: pointer of struct cm3218x.
>>>>>>> @chip
>>>>>>>
>>>>>>>> + *
>>>>>>>> + * Following SMBus protocol, ARA register is available only when
>>>>>>>> interrupt
>>>>>>>> + * event happened.  Read it to clean interrupt event.  Otherwise,
>>>>>> other
>>>>>>>> + * device address/registers will be blocked during interrupt
>>>> event.
>>>>>>>> + *
>>>>>>>> + * Return: 0 for success; otherwise for error code.
>>>>>>>> + */
>>>>>>>> +static int cm3218x_read_ara(struct cm3218x_chip *chip)
>>>>>>>> +{
>>>>>>>> + struct i2c_client *client = chip->client;
>>>>>>>> + int status;
>>>>>>>> + unsigned short addr;
>>>>>>>> +
>>>>>>> this looks dangerous: temporarily changing the I2C chip address!
>>>>>>>
>>>>>>>> + addr = client->addr;
>>>>>>>> + client->addr = 0x0C;
>>>>>>>> + status = i2c_smbus_read_byte(client);
>>>>>>>> + client->addr = addr;
>>>>>>>> +
>>>>>>>> + if (status < 0)
>>>>>>>> + return -ENODEV;
>>>>>>>> +
>>>>>>>> + return status;
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +/**
>>>>>>>> + * cm3218x_interrupt_config() - Enable/Disable CM3218x interrupt
>>>>>>>> + * @cm3218x: pointer of struct cm3218x.
>>>>>>> @chip: pointer to struct cm3218x_chip
>>>>>>>
>>>>>>>> + * @enable: 0 to disable; otherwise to enable
>>>>>>>> + *
>>>>>>>> + * Config CM3218x interrupt control bit.
>>>>>>>> + *
>>>>>>>> + * Return: 0 for success; otherwise for error code.
>>>>>>>> + */
>>>>>>>> +static int cm3218x_interrupt_config(struct cm3218x_chip *chip,
>>>> int
>>>>>>>> enable)
>>>>>>>> +{
>>>>>>>> + struct i2c_client *client = chip->client;
>>>>>>>> + struct cmdev *cmdev = chip->cmdev;
>>>>>>>> + int status;
>>>>>>>> +
>>>>>>>> + if (!cmdev)
>>>>>>>> + return -ENODEV;
>>>>>>>> +
>>>>>>>> + /* Force to clean interrupt */
>>>>>>>> + if (cmdev->int_type == INT_TYPE_I2C) {
>>>>>>>> + status = i2c_smbus_read_word_data(client,
>>>>>>>> + CM3218x_REG_ADDR_STATUS);
>>>>>>>> + if (status < 0)
>>>>>>>> + cmdev->int_type = INT_TYPE_SMBUS;
>>>>>>>> + }
>>>>>>>> + if (cmdev->int_type == INT_TYPE_SMBUS)
>>>>>>>> + cm3218x_read_ara(chip);
>>>>>>>> +
>>>>>>>> + if (enable)
>>>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD] |=
>>>>>>>> + CM3218x_CMD_ALS_INT_EN;
>>>>>>>> + else
>>>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD] &=
>>>>>>>> + ~CM3218x_CMD_ALS_INT_EN;
>>>>>>>> +
>>>>>>>> + status = i2c_smbus_write_word_data(client, CM3218x_REG_ADDR_CMD,
>>>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD]);
>>>>>>>> +
>>>>>>>> + if (status < 0)
>>>>>>>> + return -ENODEV;
>>>>>>>> +
>>>>>>>> + return status;
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +/**
>>>>>>>> + * cm3218x_acpi_get_cpm_info() - Get CPM object from ACPI
>>>>>>>> + * @client pointer of struct i2c_client.
>>>>>>>> + * @obj_name pointer of ACPI object name.
>>>>>>>> + * @count maximum size of return array.
>>>>>>>> + * @vals pointer of array for return elements.
>>>>>>>> + *
>>>>>>>> + * Convert ACPI CPM table to array. Special thanks Srinivas
>>>>>> Pandruvada's
>>>>>>>> + * help to implement this routine.
>>>>>>>> + *
>>>>>>>> + * Return: -ENODEV for fail.  Otherwise is number of elements.
>>>>>>>> + */
>>>>>>>> +static int cm3218x_acpi_get_cpm_info(struct i2c_client *client,
>>>>>> char
>>>>>>>> *obj_name,
>>>>>>>> + int count, u64 *vals)
>>>>>>>> +{
>>>>>>>> + acpi_handle handle;
>>>>>>>> + struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
>>>>>>>> + int i;
>>>>>>>> + acpi_status status;
>>>>>>>> + union acpi_object *cpm = NULL;
>>>>>>> no need to initialize cpm
>>>>>>>
>>>>>>>> +
>>>>>>>> + handle = ACPI_HANDLE(&client->dev);
>>>>>>>> + if (!handle)
>>>>>>>> + return -ENODEV;
>>>>>>>> +
>>>>>>>> + status = acpi_evaluate_object(handle, obj_name, NULL, &buffer);
>>>>>>>> + if (ACPI_FAILURE(status)) {
>>>>>>>> + dev_err(&client->dev, "object %s not found\n", obj_name);
>>>>>>>> + return -ENODEV;
>>>>>>>> + }
>>>>>>>> +
>>>>>>>> + cpm = buffer.pointer;
>>>>>>>> + for (i = 0; i < cpm->package.count && i < count; ++i) {
>>>>>>>> + union acpi_object *elem;
>>>>>>>> + elem = &(cpm->package.elements[i]);
>>>>>>>> + vals[i] = elem->integer.value;
>>>>>>>> + }
>>>>>>>> +
>>>>>>>> + kfree(buffer.pointer);
>>>>>>>> +
>>>>>>>> + return cpm->package.count;
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +/**
>>>>>>>> + * cm3218x_reg_init() - Initialize CM3218x registers
>>>>>>>> + * @cm3218x: pointer of struct cm3218x.
>>>>>>>> + *
>>>>>>>> + * Initialize CM3218x ambient light sensor register to default
>>>>>> values.
>>>>>>>> + *
>>>>>>>> +  Return: 0 for success; otherwise for error code.
>>>>>>>> + */
>>>>>>>> +static int cm3218x_reg_init(struct cm3218x_chip *chip)
>>>>>>>> +{
>>>>>>>> + struct i2c_client *client = chip->client;
>>>>>>>> + int i;
>>>>>>>> + s32 ret;
>>>>>>>> + int cpm_elem_count;
>>>>>>>> + u64 cpm_elems[20];
>>>>>>>> + struct cmdev *cmdev;
>>>>>>>> +
>>>>>>>> + /* Default device */
>>>>>>>> + chip->cmdev = &cm3218;
>>>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD] = CM3218x_CMD_DEFAULT;
>>>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_WH] = CM3218x_WH_DEFAULT;
>>>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_WL] = CM3218x_WL_DEFAULT;
>>>>>>>> +
>>>>>>>> + /* Disable interrupt */
>>>>>>>> + cm3218x_interrupt_config(chip, 0);
>>>>>>>> +
>>>>>>>> + /* Disable Test Mode */
>>>>>>>> + i2c_smbus_write_word_data(client, CM3218x_REG_ADDR_TEST,
>>>> 0x0000);
>>>>>>>> +
>>>>>>>> + /* Disable device */
>>>>>>>> + i2c_smbus_write_word_data(client, CM3218x_REG_ADDR_CMD,
>>>>>>>> + CM3218x_CMD_ALS_DISABLE);
>>>>>>>> +
>>>>>>>> + /* Identify device */
>>>>>>>> + ret = i2c_smbus_read_word_data(client, CM3218x_REG_ADDR_ID);
>>>>>>>> + if (ret < 0)
>>>>>>>> + return ret;
>>>>>>>> + switch (ret & 0xFF) {
>>>>>>>> + case 0x18:
>>>>>>>> + cmdev = chip->cmdev = &cm3218;
>>>>>>>> + if (ret & 0x0800)
>>>>>>>> + cmdev->int_type = INT_TYPE_I2C;
>>>>>>>> + else
>>>>>>>> + cmdev->int_type = INT_TYPE_SMBUS;
>>>>>>>> + break;
>>>>>>>> + case 0x81:
>>>>>>>> + cmdev = chip->cmdev = &cm32181;
>>>>>>>> + break;
>>>>>>>> + case 0x82:
>>>>>>>> + cmdev = chip->cmdev = &cm32182;
>>>>>>>> + break;
>>>>>>>> + default:
>>>>>>>> + return -ENODEV;
>>>>>>>> + }
>>>>>>>> +
>>>>>>>> + if (ACPI_HANDLE(&client->dev)) {
>>>>>>>> + /* Load from ACPI */
>>>>>>>> + cpm_elem_count = cm3218x_acpi_get_cpm_info(client, "CPM0",
>>>>>>>> + ARRAY_SIZE(cpm_elems),
>>>>>>>> + cpm_elems);
>>>>>>>> + if (cpm_elem_count > 0) {
>>>>>>>> + int header_num = 3;
>>>>>>>> + int reg_num = cpm_elem_count - header_num;
>>>>>>>> +
>>>>>>>> + cmdev->regs_bmp = cpm_elems[2];
>>>>>>>> + for (i = 0; i < reg_num; i++)
>>>>>>>> + if (cmdev->regs_bmp & (1<<i))
>>>>>>>> + chip->conf_regs[i] =
>>>>>>>> + cpm_elems[header_num+i];
>>>>>>>> + }
>>>>>>>> +
>>>>>>>> + cpm_elem_count = cm3218x_acpi_get_cpm_info(client, "CPM1",
>>>>>>>> + ARRAY_SIZE(cpm_elems),
>>>>>>>> + cpm_elems);
>>>>>>>> + if (cpm_elem_count > 0) {
>>>>>>>> + cmdev->mlux_per_bit = (int)cpm_elems[0] / 100;
>>>>>>>> + cmdev->calibscale = (int)cpm_elems[1];
>>>>>>>> + }
>>>>>>>> + }
>>>>>>>> +
>>>>>>>> + /* Force to disable interrupt */
>>>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD] &=
>>>> ~CM3218x_CMD_ALS_INT_EN;
>>>>>>>> +
>>>>>>>> + /* Initialize registers*/
>>>>>>> whitespace
>>>>>>>
>>>>>>>> + for (i = 0; i < CM3218x_CONF_REG_NUM; i++) {
>>>>>>>> + if (cmdev->regs_bmp & (1<<i)) {
>>>>>>>> + ret = i2c_smbus_write_word_data(client, i,
>>>>>>>> + chip->conf_regs[i]);
>>>>>>>> + if (ret < 0)
>>>>>>>> + return ret;
>>>>>>>> + }
>>>>>>>> + }
>>>>>>>> +
>>>>>>>> + return 0;
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +/**
>>>>>>>> + *  cm3218x_read_als_it() - Get sensor integration time (ms)
>>>>>>>> + *  @cm3218x: pointer of struct cm3218x
>>>>>>>> + *  @val2: pointer of int to load the als_it value.
>>>>>>>> + *
>>>>>>>> + *  Report the current integartion time by millisecond.
>>>>>>> integration time in milliseconds
>>>>>>>
>>>>>>>> + *
>>>>>>>> + *  Return: IIO_VAL_INT_PLUS_MICRO for success, otherwise
>>>> -EINVAL.
>>>>>>>> + */
>>>>>>>> +static int cm3218x_read_als_it(struct cm3218x_chip *chip, int
>>>>>> *val2)
>>>>>>>> +{
>>>>>>>> + struct cmdev *cmdev = chip->cmdev;
>>>>>>>> + u16 als_it;
>>>>>>>> + int i;
>>>>>>>> +
>>>>>>>> + als_it = chip->conf_regs[CM3218x_REG_ADDR_CMD];
>>>>>>>> + als_it &= CM3218x_CMD_ALS_IT_MASK;
>>>>>>>> + als_it >>= CM3218x_CMD_ALS_IT_SHIFT;
>>>>>>>> + for (i = 0; i < cmdev->num_als_it; i++) {
>>>>>>>> + if (als_it == cmdev->als_it_bits[i]) {
>>>>>>>> + *val2 = cmdev->als_it_values[i];
>>>>>>>> + return IIO_VAL_INT_PLUS_MICRO;
>>>>>>>> + }
>>>>>>>> + }
>>>>>>>> +
>>>>>>>> + return -EINVAL;
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +/**
>>>>>>>> + * cm3218x_write_als_it() - Write sensor integration time
>>>>>>>> + * @cm3218x: pointer of struct cm3218x.
>>>>>>>> + * @val: integration time by millisecond.
>>>>>>>> + *
>>>>>>>> + * Convert integration time (ms) to sensor value.
>>>>>>>> + *
>>>>>>>> + * Return: i2c_smbus_write_word_data command return value.
>>>>>>>> + */
>>>>>>>> +static int cm3218x_write_als_it(struct cm3218x_chip *chip, int
>>>> val)
>>>>>>>> +{
>>>>>>>> + struct i2c_client *client = chip->client;
>>>>>>>> + struct cmdev *cmdev = chip->cmdev;
>>>>>>>> + u16 als_it;
>>>>>>>> + int ret, i;
>>>>>>>> +
>>>>>>>> + for (i = 0; i < cmdev->num_als_it; i++)
>>>>>>>> + if (val <= cmdev->als_it_values[i])
>>>>>>>> + break;
>>>>>>>> + if (i >= cmdev->num_als_it)
>>>>>>>> + i = cmdev->num_als_it - 1;
>>>>>>>> +
>>>>>>>> + als_it = cmdev->als_it_bits[i];
>>>>>>>> + als_it <<= CM3218x_CMD_ALS_IT_SHIFT;
>>>>>>>> +
>>>>>>>> + mutex_lock(&chip->lock);
>>>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD] &=
>>>>>>>> + ~CM3218x_CMD_ALS_IT_MASK;
>>>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD] |=
>>>>>>>> + als_it;
>>>>>>>> + ret = i2c_smbus_write_word_data(client, CM3218x_REG_ADDR_CMD,
>>>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_CMD]);
>>>>>>>> + mutex_unlock(&chip->lock);
>>>>>>>> +
>>>>>>>> + return ret;
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +/**
>>>>>>>> + * cm3218x_get_lux() - report current lux value
>>>>>>>> + * @cm3218x: pointer of struct cm3218x.
>>>>>>>> + *
>>>>>>>> + * Convert sensor raw data to lux.  It depends on integration
>>>>>>>> + * time and claibscale variable.
>>>>>>> calibscale
>>>>>>>
>>>>>>>> + *
>>>>>>>> + * Return: Positive value is lux, otherwise is error code.
>>>>>>>> + */
>>>>>>>> +static int cm3218x_get_lux(struct cm3218x_chip *chip)
>>>>>>>> +{
>>>>>>>> + struct i2c_client *client = chip->client;
>>>>>>>> + struct cmdev *cmdev = chip->cmdev;
>>>>>>>> + int ret;
>>>>>>>> + int als_it;
>>>>>>>> + int lux;
>>>>>>> lux variable is not needed
>>>>>>>
>>>>>>>> + u64 tmp;
>>>>>>>> +
>>>>>>>> + /* Calculate mlux per bit based on als_it */
>>>>>>>> + ret = cm3218x_read_als_it(chip, &als_it);
>>>>>>>> + if (ret < 0)
>>>>>>>> + return -EINVAL;
>>>>>>>> + tmp = (__force u64)cmdev->mlux_per_bit;
>>>>>>>> + tmp *= cmdev->mlux_per_bit_base_it;
>>>>>>>> + tmp = div_u64(tmp, als_it);
>>>>>>>> +
>>>>>>>> + /* Get als_raw */
>>>>>>>> + if (!(chip->conf_regs[CM3218x_REG_ADDR_CMD] &
>>>>>> CM3218x_CMD_ALS_INT_EN))
>>>>>>>> + chip->als_raw = i2c_smbus_read_word_data(
>>>>>>>> + client,
>>>>>>>> + CM3218x_REG_ADDR_ALS);
>>>>>>>> + if (chip->als_raw < 0)
>>>>>>>> + return chip->als_raw;
>>>>>>>> +
>>>>>>>> + tmp *= chip->als_raw;
>>>>>>>> + tmp *= cmdev->calibscale;
>>>>>>>> + tmp = div_u64(tmp, CM3218x_CALIBSCALE_RESOLUTION);
>>>>>>>> + tmp = div_u64(tmp, MLUX_PER_LUX);
>>>>>>>> +
>>>>>>>> + if (tmp > 0xFFFF)
>>>>>>>> + tmp = 0xFFFF;
>>>>>>>> +
>>>>>>>> + lux = (int)tmp;
>>>>>>>> + return lux;
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +static int cm3218x_read_raw(struct iio_dev *indio_dev,
>>>>>>>> + struct iio_chan_spec const *chan,
>>>>>>>> + int *val, int *val2, long mask)
>>>>>>>> +{
>>>>>>>> + struct cm3218x_chip *chip = iio_priv(indio_dev);
>>>>>>>> + struct cmdev *cmdev = chip->cmdev;
>>>>>>>> + int ret;
>>>>>>>> +
>>>>>>>> + switch (mask) {
>>>>>>>> + case IIO_CHAN_INFO_PROCESSED:
>>>>>>>> + ret = cm3218x_get_lux(chip);
>>>>>>>> + if (ret < 0)
>>>>>>>> + return ret;
>>>>>>>> + *val = ret;
>>>>>>>> + return IIO_VAL_INT;
>>>>>>>> + case IIO_CHAN_INFO_CALIBSCALE:
>>>>>>>> + *val = cmdev->calibscale;
>>>>>>>> + return IIO_VAL_INT;
>>>>>>>> + case IIO_CHAN_INFO_INT_TIME:
>>>>>>>> + *val = 0;
>>>>>>>> + ret = cm3218x_read_als_it(chip, val2);
>>>>>>>> + return ret;
>>>>>>>> + }
>>>>>>>> +
>>>>>>>> + return -EINVAL;
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +static int cm3218x_write_raw(struct iio_dev *indio_dev,
>>>>>>>> + struct iio_chan_spec const *chan,
>>>>>>>> + int val, int val2, long mask)
>>>>>>>> +{
>>>>>>>> + struct cm3218x_chip *chip = iio_priv(indio_dev);
>>>>>>>> + struct cmdev *cmdev = chip->cmdev;
>>>>>>>> + int ret;
>>>>>>> ret not needed
>>>>>>>
>>>>>>>> +
>>>>>>>> + switch (mask) {
>>>>>>>> + case IIO_CHAN_INFO_CALIBSCALE:
>>>>>>>> + cmdev->calibscale = val;
>>>>>>>> + return val;
>>>>>>>> + case IIO_CHAN_INFO_INT_TIME:
>>>>>>> val==0 could be checked here
>>>>>>>
>>>>>>>> + ret = cm3218x_write_als_it(chip, val2);
>>>>>>>> + return ret;
>>>>>>>> + }
>>>>>>>> +
>>>>>>>> + return -EINVAL;
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +/**
>>>>>>>> + * cm3218x_get_it_available() - Get available ALS IT value
>>>>>>>> + * @dev: pointer of struct device.
>>>>>>>> + * @attr: pointer of struct device_attribute.
>>>>>>>> + * @buf: pointer of return string buffer.
>>>>>>>> + *
>>>>>>>> + * Display the available integration time values by millisecond.
>>>>>>>> + *
>>>>>>>> + * Return: string length.
>>>>>>>> + */
>>>>>>>> +static ssize_t cm3218x_get_it_available(struct device *dev,
>>>>>>>> + struct device_attribute *attr, char *buf)
>>>>>>>> +{
>>>>>>>> + struct cm3218x_chip *chip = iio_priv(dev_to_iio_dev(dev));
>>>>>>>> + struct cmdev *cmdev = chip->cmdev;
>>>>>>>> + int i, len;
>>>>>>>> +
>>>>>>>> + for (i = 0, len = 0; i < cmdev->num_als_it; i++)
>>>>>>>> + len += sprintf(buf + len, "0.%06u ", cmdev->als_it_values[i]);
>>>>>>> scnprintf(buf+len, PAGESIZE-len, ...) could be used
>>>>>>>
>>>>>>>> + return len + sprintf(buf + len, "\n");
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +/**
>>>>>>>> + * cm3218x_threshold_update() - Update the threshold registers.
>>>>>>>> + * @dev: pointer of struct cm3218x_chip.
>>>>>>> @chip
>>>>>>>
>>>>>>>> + * @percent: +/- percent.
>>>>>>>> + *
>>>>>>>> + * Based on the current ALS value, tupdate the hi and low
>>>> threshold
>>>>>>>> registers.
>>>>>>>> + *
>>>>>>>> + * Return: string length.
>>>>>>> definitely not the string length
>>>>>>>
>>>>>>>> + */
>>>>>>>> +static int cm3218x_threshold_update(struct cm3218x_chip *chip,
>>>> int
>>>>>>>> percent)
>>>>>>>> +{
>>>>>>>> + struct i2c_client *client = chip->client;
>>>>>>>> + int ret;
>>>>>>>> + int wh, wl;
>>>>>>>> +
>>>>>>>> + ret = chip->als_raw = i2c_smbus_read_word_data(client,
>>>>>>>> + CM3218x_REG_ADDR_ALS);
>>>>>>>> + if (ret < 0)
>>>>>>>> + return ret;
>>>>>>>> +
>>>>>>>> + wh = wl = ret;
>>>>>>>> + ret *= percent;
>>>>>>>> + ret /= 100;
>>>>>>>> + if (ret < 1)
>>>>>>>> + ret = 1;
>>>>>>>> + wh += ret;
>>>>>>>> + wl -= ret;
>>>>>>>> + if (wh > 65535)
>>>>>>>> + wh = 65535;
>>>>>>>> + if (wl < 0)
>>>>>>>> + wl = 0;
>>>>>>>> +
>>>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_WH] = wh;
>>>>>>>> + ret = i2c_smbus_write_word_data(
>>>>>>>> + client,
>>>>>>>> + CM3218x_REG_ADDR_WH,
>>>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_WH]);
>>>>>>>> + if (ret < 0)
>>>>>>>> + return ret;
>>>>>>>> +
>>>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_WL] = wl;
>>>>>>>> + ret = i2c_smbus_write_word_data(
>>>>>>>> + client,
>>>>>>>> + CM3218x_REG_ADDR_WL,
>>>>>>>> + chip->conf_regs[CM3218x_REG_ADDR_WL]);
>>>>>>> just
>>>>>>> return ret;
>>>>>>>
>>>>>>>> + if (ret < 0)
>>>>>>>> + return ret;
>>>>>>>> +
>>>>>>>> + return 0;
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +/**
>>>>>>>> + * cm3218x_event_handler() - Interrupt handling routine.
>>>>>>>> + * @irq: irq number.
>>>>>>>> + * @private: pointer of void.
>>>>>>>> + *
>>>>>>>> + * Clean interrupt and reset threshold registers.
>>>>>>>> + *
>>>>>>>> + * Return: string length.
>>>>>>>
>>>>>>>> + */
>>>>>>>> +static irqreturn_t cm3218x_event_handler(int irq, void *private)
>>>>>>>> +{
>>>>>>>> + struct iio_dev *dev_info = private;
>>>>>>>> + struct cm3218x_chip *chip = iio_priv(dev_info);
>>>>>>>> + int ret;
>>>>>>>> +
>>>>>>>> + mutex_lock(&chip->lock);
>>>>>>>> +
>>>>>>>> + /* Disable interrupt */
>>>>>>>> + ret = cm3218x_interrupt_config(chip, 0);
>>>>>>>> + if (ret < 0)
>>>>>>>> + goto error_handler_unlock;
>>>>>>>> +
>>>>>>>> + /* Update Hi/Lo windows */
>>>>>>>> + ret = cm3218x_threshold_update(chip, CM3218x_THRESHOLD_PERCENT);
>>>>>>>> + if (ret < 0)
>>>>>>>> + goto error_handler_unlock;
>>>>>>>> +
>>>>>>>> + /* Enable interrupt */
>>>>>>>> + ret = cm3218x_interrupt_config(chip, 1);
>>>>>>>> + if (ret < 0)
>>>>>>>> + goto error_handler_unlock;
>>>>>>>> +
>>>>>>>> + mutex_unlock(&chip->lock);
>>>>>>>> +
>>>>>>>> + return IRQ_HANDLED;
>>>>>>>> +
>>>>>>>> +error_handler_unlock:
>>>>>>>> + mutex_unlock(&chip->lock);
>>>>>>>> + return IRQ_NONE;
>>>>>>> I think it should be IRQ_HANDLED always
>>>>>>> there is no check if the interrupt indeed stems from this device
>>>>>>>
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +static const struct iio_chan_spec cm3218x_channels[] = {
>>>>>>>> + {
>>>>>>>> + .type = IIO_LIGHT,
>>>>>>>> + .info_mask_separate =
>>>>>>>> + BIT(IIO_CHAN_INFO_PROCESSED) |
>>>>>>>> + BIT(IIO_CHAN_INFO_CALIBSCALE) |
>>>>>>>> + BIT(IIO_CHAN_INFO_INT_TIME),
>>>>>>>> + }
>>>>>>>> +};
>>>>>>>> +
>>>>>>>> +static IIO_DEVICE_ATTR(in_illuminance_integration_time_available,
>>>>>>>> + S_IRUGO, cm3218x_get_it_available, NULL, 0);
>>>>>>>> +
>>>>>>>> +static struct attribute *cm3218x_attributes[] = {
>>>>>>>> +
>>>> &iio_dev_attr_in_illuminance_integration_time_available.dev_attr.attr,
>>>>>>>> + NULL,
>>>>>>>> +};
>>>>>>>> +
>>>>>>>> +static const struct attribute_group cm3218x_attribute_group = {
>>>>>>>> + .attrs = cm3218x_attributes
>>>>>>>> +};
>>>>>>>> +
>>>>>>>> +static const struct iio_info cm3218x_info = {
>>>>>>>> + .driver_module = THIS_MODULE,
>>>>>>>> + .read_raw = &cm3218x_read_raw,
>>>>>>>> + .write_raw = &cm3218x_write_raw,
>>>>>>>> + .attrs = &cm3218x_attribute_group,
>>>>>>>> +};
>>>>>>>> +
>>>>>>>> +static int cm3218x_probe(struct i2c_client *client,
>>>>>>>> + const struct i2c_device_id *id)
>>>>>>>> +{
>>>>>>>> + struct cm3218x_chip *chip;
>>>>>>>> + struct iio_dev *indio_dev;
>>>>>>>> + int ret;
>>>>>>>> +
>>>>>>>> + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
>>>>>>>> + if (!indio_dev) {
>>>>>>>> + dev_err(&client->dev, "devm_iio_device_alloc failed\n");
>>>>>>>> + return -ENOMEM;
>>>>>>>> + }
>>>>>>>> +
>>>>>>>> + chip = iio_priv(indio_dev);
>>>>>>>> + i2c_set_clientdata(client, indio_dev);
>>>>>>>> + chip->client = client;
>>>>>>>> +
>>>>>>>> + mutex_init(&chip->lock);
>>>>>>>> + indio_dev->dev.parent = &client->dev;
>>>>>>>> + indio_dev->channels = cm3218x_channels;
>>>>>>>> + indio_dev->num_channels = ARRAY_SIZE(cm3218x_channels);
>>>>>>>> + indio_dev->info = &cm3218x_info;
>>>>>>>> + if (id && id->name)
>>>>>>>> + indio_dev->name = id->name;
>>>>>>>> + else
>>>>>>>> + indio_dev->name = (char *)dev_name(&client->dev);
>>>>>>>> + indio_dev->modes = INDIO_DIRECT_MODE;
>>>>>>>> +
>>>>>>>> + ret = cm3218x_reg_init(chip);
>>>>>>>> + if (ret) {
>>>>>>>> + dev_err(&client->dev,
>>>>>>>> + "%s: register init failed\n",
>>>>>>>> + __func__);
>>>>>>>> + return ret;
>>>>>>>> + }
>>>>>>>> +
>>>>>>>> + if (client->irq) {
>>>>>>>> + ret = request_threaded_irq(client->irq,
>>>>>>>> + NULL,
>>>>>>>> + cm3218x_event_handler,
>>>>>>>> + IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
>>>>>>>> + "cm3218x_event",
>>>>>>>> + indio_dev);
>>>>>>>> +
>>>>>>>> + if (ret < 0) {
>>>>>>>> + dev_err(&client->dev, "irq request error %d\n",
>>>>>>>> + -ret);
>>>>>>>> + goto error_disable_int;
>>>>>>>> + }
>>>>>>>> + }
>>>>>>>> +
>>>>>>>> + ret = iio_device_register(indio_dev);
>>>>>>>> + if (ret < 0) {
>>>>>>>> + dev_err(&client->dev,
>>>>>>>> + "%s: regist device failed\n",
>>>>>>>> + __func__);
>>>>>>>> + goto error_free_irq;
>>>>>>>> + }
>>>>>>>> +
>>>>>>>> + if (client->irq) {
>>>>>>>> + ret = cm3218x_threshold_update(chip, CM3218x_THRESHOLD_PERCENT);
>>>>>>>> + if (ret < 0)
>>>>>>>> + goto error_free_irq;
>>>>>>>> +
>>>>>>>> + ret = cm3218x_interrupt_config(chip, 1);
>>>>>>>> + if (ret < 0)
>>>>>>>> + goto error_free_irq;
>>>>>>>> + }
>>>>>>>> +
>>>>>>>> + return 0;
>>>>>>>> +
>>>>>>>> +error_free_irq:
>>>>>>>> + free_irq(client->irq, indio_dev);
>>>>>>>> +error_disable_int:
>>>>>>>> + cm3218x_interrupt_config(chip, 0);
>>>>>>>> + return ret;
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +static int cm3218x_remove(struct i2c_client *client)
>>>>>>>> +{
>>>>>>>> + struct iio_dev *indio_dev = i2c_get_clientdata(client);
>>>>>>>> + struct cm3218x_chip *chip = iio_priv(indio_dev);
>>>>>>>> +
>>>>>>>> + cm3218x_interrupt_config(chip, 0);
>>>>>>>> + if (client->irq)
>>>>>>>> + free_irq(client->irq, indio_dev);
>>>>>>>> + iio_device_unregister(indio_dev);
>>>>>>>> + return 0;
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +static const struct i2c_device_id cm3218x_id[] = {
>>>>>>>> + { "cm3218x", 0},
>>>>>>>> + { }
>>>>>>>> +};
>>>>>>>> +
>>>>>>>> +MODULE_DEVICE_TABLE(i2c, cm3218x_id);
>>>>>>>> +
>>>>>>>> +static const struct of_device_id cm3218x_of_match[] = {
>>>>>>>> + { .compatible = "capella,cm3218x" },
>>>>>>>> + { }
>>>>>>>> +};
>>>>>>>> +
>>>>>>>> +static const struct acpi_device_id cm3218x_acpi_match[] = {
>>>>>>>> + { "CPLM3218", 0},
>>>>>>>> + {},
>>>>>>>> +};
>>>>>>>> +
>>>>>>>> +MODULE_DEVICE_TABLE(acpi, cm3218x_acpi_match);
>>>>>>>> +
>>>>>>>> +static struct i2c_driver cm3218x_driver = {
>>>>>>>> + .driver = {
>>>>>>>> + .name = "cm3218x",
>>>>>>>> + .acpi_match_table = ACPI_PTR(cm3218x_acpi_match),
>>>>>>>> + .of_match_table = of_match_ptr(cm3218x_of_match),
>>>>>>>> + .owner = THIS_MODULE,
>>>>>>>> + },
>>>>>>>> + .id_table = cm3218x_id,
>>>>>>>> + .probe = cm3218x_probe,
>>>>>>>> + .remove = cm3218x_remove,
>>>>>>>> +};
>>>>>>>> +
>>>>>>>> +module_i2c_driver(cm3218x_driver);
>>>>>>>> +
>>>>>>>> +MODULE_AUTHOR("Kevin Tsai <ktsai-GubuWUlQtMwciDkP5Hr2oA@public.gmane.org>");
>>>>>>>> +MODULE_DESCRIPTION("CM3218x ambient light sensor driver");
>>>>>>>> +MODULE_LICENSE("GPL");
>>>>>>>>
>>>>>>> --
>>>>>>>
>>>>>>> Peter Meerwald
>>>>>>> +43-664-2444418 (mobile)
>>
>> --
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