On March 20, 2014 12:58:02 AM GMT+00:00, Kevin Tsai <ktsai@xxxxxxxxxxxxxxxx> 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?
>
>Thanks.
>
>Kevin Tsai
>03/19/14
>
>----- Original Message -----
>From: "Peter Meerwald" <pmeerw@xxxxxxxxxx>
>To: "Kevin Tsai" <ktsai@xxxxxxxxxxxxxxxx>
>Cc: "Jonathan Cameron" <jic23@xxxxxxxxxx>; <linux-iio@xxxxxxxxxxxxxxx>
>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@xxxxxxxxxxxxxxxx>
>>> + *
>>> + * 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@xxxxxxxxxxxxxxx>
>>> + * 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@xxxxxxxxxxxxxxxx>");
>>> +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.
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