On 24/07/16 10:59, Jonathan Cameron wrote:
> On 24/07/16 08:52, Linus Walleij wrote:
>> This adds a driver for the Asahi Kasei AK8975 and its sibling
>> AMI305 magnetometers. It was deployed on scale in 2009 on a
>> multitude of devices. It is distincly different from AK8973
>> and AK8975 and needs its own driver.
>>
>> This patch is based on the long lost work of Samu Onkalo at Nokia,
>> who made a misc character device driver for the Maemo/MeeGo Nokia
>> devices, before the time of the IIO subsystem. It was mounted in e.g.
>> the Nokia N950, N8, N86, N97 etc. It is also mounted on the
>> ST-Ericsson HREF reference designs.
>>
>> It works nicely in sysfs:
>>
>> $ cat in_magn_x_raw && cat in_magn_y_raw && cat in_magn_z_raw
>> -55
>> -101
>> 161
>>
>> And with buffered reads using a simple HRTimer trigger:
>> $ generic_buffer -c10 -a -n ak8974 -t foo
>> iio device number being used is 3
>> iio trigger number being used is 2
>> No channels are enabled, enabling all channels
>> Enabling: in_magn_x_en
>> Enabling: in_magn_y_en
>> Enabling: in_magn_z_en
>> Enabling: in_timestamp_en
>> /sys/bus/iio/devices/iio:device3 foo
>> -58.000000 -102.000000 157.000000 946684970985321044
>> -60.000000 -98.000000 159.000000 946684971012237548
>> -60.000000 -106.000000 163.000000 946684971032257080
>> -62.000000 -94.000000 169.000000 946684971052185058
>> -58.000000 -98.000000 163.000000 946684971072204589
>> -54.000000 -100.000000 163.000000 946684971092224121
>> -53.000000 -103.000000 164.000000 946684971112731933
>> -50.000000 -102.000000 165.000000 946684971132232666
>> -61.000000 -101.000000 164.000000 946684971152191162
>> -57.000000 -99.000000 168.000000 946684971172210693
>> Disabling: in_magn_x_en
>> Disabling: in_magn_y_en
>> Disabling: in_magn_z_en
>> Disabling: in_timestamp_en
>>
>> I cannot currently scale these raw values to gauss. This is
>> because of lack of documentation. I have sent a request for
>> a datasheet to Asahi Kasei.
>>
>> The driver can optionally use a DRDY line IRQ to capture data,
>> else it will sleep and poll.
>>
>> Cc: Samu Onkalo <samu.onkalo@xxxxxxxxx>
>> Cc: Sebastian Reichel <sre@xxxxxxxxxx>
>> Tested-By: Sebastian Reichel <sre@xxxxxxxxxx>
>> Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
>
> Excellent driver. Applied to the togreg branch of iio.git
> - initially pushed out as testing for the autobuilders to play with
> it.
Ah, crossed with the timestamp changes. I've fixed it up.
Jonathan
>
> Thanks,
>
> Jonathan
>> ---
>> ChangeLog v3->v4:
>> - Add support for an optional mounting matrix
>> ChangeLog v2->v3:
>> - Employ the blankline-before-return-if-last-statement-in-a-function
>> syntax design pattern.
>> - Join dereferencing of state container struct into a single line
>> in runtime suspend/resume
>> - Fix some missing prefixes for ak8974_avdd_reg; etc
>> - Use GOTO try/catch construction in ak8974_runtime_resume()
>> - Fix locking issues found by coccinelle
>> - Speling
>> ChangeLog v1->v2:
>> - Drop pointless dependency on GPIOLIB in Kconfig
>> - Drop the "clever" ret |= returncode code and bail out directly
>> on any regmap errors
>> - Add a mutex around measurements so we don't collide, this
>> could happen atleast in theory
>> - Inline the read_axes() function into the *read_raw() function
>> and avoid a pointless helper function
>> - Augment HW value buffer to be 8*16 bits = 2*64 bits so that it
>> is aligned to 64bit boundary for the triggered buffer
>> - Fix a pair of missing if () {} brackets in the runtime resume
>> function
>> - Drop erroneous AK8974/5 claim in module description
>> - Various whitespace fixes
>> ---
>> MAINTAINERS | 7 +
>> drivers/iio/magnetometer/Kconfig | 16 +-
>> drivers/iio/magnetometer/Makefile | 1 +
>> drivers/iio/magnetometer/ak8974.c | 871 ++++++++++++++++++++++++++++++++++++++
>> 4 files changed, 894 insertions(+), 1 deletion(-)
>> create mode 100644 drivers/iio/magnetometer/ak8974.c
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index e1b090f86e0d..ab042b142cef 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -1930,6 +1930,13 @@ S: Maintained
>> F: drivers/media/i2c/as3645a.c
>> F: include/media/i2c/as3645a.h
>>
>> +ASAHI KASEI AK8974 DRIVER
>> +M: Linus Walleij <linus.walleij@xxxxxxxxxx>
>> +L: linux-iio@xxxxxxxxxxxxxxx
>> +W: http://www.akm.com/
>> +S: Supported
>> +F: drivers/iio/magnetometer/ak8974.c
>> +
>> ASC7621 HARDWARE MONITOR DRIVER
>> M: George Joseph <george.joseph@xxxxxxxxxxxxx>
>> L: linux-hwmon@xxxxxxxxxxxxxxx
>> diff --git a/drivers/iio/magnetometer/Kconfig b/drivers/iio/magnetometer/Kconfig
>> index 84e6559ccc65..76fcb7b51b45 100644
>> --- a/drivers/iio/magnetometer/Kconfig
>> +++ b/drivers/iio/magnetometer/Kconfig
>> @@ -5,8 +5,22 @@
>>
>> menu "Magnetometer sensors"
>>
>> +config AK8974
>> + tristate "Asahi Kasei AK8974 3-Axis Magnetometer"
>> + depends on I2C
>> + depends on OF
>> + select REGMAP_I2C
>> + select IIO_BUFFER
>> + select IIO_TRIGGERED_BUFFER
>> + help
>> + Say yes here to build support for Asahi Kasei AK8974 or
>> + AMI305 I2C-based 3-axis magnetometer chips.
>> +
>> + To compile this driver as a module, choose M here: the module
>> + will be called ak8974.
>> +
>> config AK8975
>> - tristate "Asahi Kasei AK 3-Axis Magnetometer"
>> + tristate "Asahi Kasei AK8975 3-Axis Magnetometer"
>> depends on I2C
>> depends on GPIOLIB || COMPILE_TEST
>> select IIO_BUFFER
>> diff --git a/drivers/iio/magnetometer/Makefile b/drivers/iio/magnetometer/Makefile
>> index 92a745c9a6e8..b86d6cb7f285 100644
>> --- a/drivers/iio/magnetometer/Makefile
>> +++ b/drivers/iio/magnetometer/Makefile
>> @@ -3,6 +3,7 @@
>> #
>>
>> # When adding new entries keep the list in alphabetical order
>> +obj-$(CONFIG_AK8974) += ak8974.o
>> obj-$(CONFIG_AK8975) += ak8975.o
>> obj-$(CONFIG_BMC150_MAGN) += bmc150_magn.o
>> obj-$(CONFIG_BMC150_MAGN_I2C) += bmc150_magn_i2c.o
>> diff --git a/drivers/iio/magnetometer/ak8974.c b/drivers/iio/magnetometer/ak8974.c
>> new file mode 100644
>> index 000000000000..e2d66b2f7afe
>> --- /dev/null
>> +++ b/drivers/iio/magnetometer/ak8974.c
>> @@ -0,0 +1,871 @@
>> +/*
>> + * Driver for the Asahi Kasei EMD Corporation AK8974
>> + * and Aichi Steel AMI305 magnetometer chips.
>> + * Based on a patch from Samu Onkalo and the AK8975 IIO driver.
>> + *
>> + * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
>> + * Copyright (c) 2010 NVIDIA Corporation.
>> + * Copyright (C) 2016 Linaro Ltd.
>> + *
>> + * Author: Samu Onkalo <samu.p.onkalo@xxxxxxxxx>
>> + * Author: Linus Walleij <linus.walleij@xxxxxxxxxx>
>> + */
>> +#include <linux/module.h>
>> +#include <linux/kernel.h>
>> +#include <linux/i2c.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/irq.h> /* For irq_get_irq_data() */
>> +#include <linux/completion.h>
>> +#include <linux/err.h>
>> +#include <linux/mutex.h>
>> +#include <linux/delay.h>
>> +#include <linux/bitops.h>
>> +#include <linux/regmap.h>
>> +#include <linux/regulator/consumer.h>
>> +#include <linux/pm_runtime.h>
>> +
>> +#include <linux/iio/iio.h>
>> +#include <linux/iio/sysfs.h>
>> +#include <linux/iio/buffer.h>
>> +#include <linux/iio/trigger.h>
>> +#include <linux/iio/trigger_consumer.h>
>> +#include <linux/iio/triggered_buffer.h>
>> +
>> +/*
>> + * 16-bit registers are little-endian. LSB is at the address defined below
>> + * and MSB is at the next higher address.
>> + */
>> +
>> +/* These registers are common for AK8974 and AMI305 */
>> +#define AK8974_SELFTEST 0x0C
>> +#define AK8974_SELFTEST_IDLE 0x55
>> +#define AK8974_SELFTEST_OK 0xAA
>> +
>> +#define AK8974_INFO 0x0D
>> +
>> +#define AK8974_WHOAMI 0x0F
>> +#define AK8974_WHOAMI_VALUE_AMI305 0x47
>> +#define AK8974_WHOAMI_VALUE_AK8974 0x48
>> +
>> +#define AK8974_DATA_X 0x10
>> +#define AK8974_DATA_Y 0x12
>> +#define AK8974_DATA_Z 0x14
>> +#define AK8974_INT_SRC 0x16
>> +#define AK8974_STATUS 0x18
>> +#define AK8974_INT_CLEAR 0x1A
>> +#define AK8974_CTRL1 0x1B
>> +#define AK8974_CTRL2 0x1C
>> +#define AK8974_CTRL3 0x1D
>> +#define AK8974_INT_CTRL 0x1E
>> +#define AK8974_INT_THRES 0x26 /* Absolute any axis value threshold */
>> +#define AK8974_PRESET 0x30
>> +
>> +/* AK8974-specific offsets */
>> +#define AK8974_OFFSET_X 0x20
>> +#define AK8974_OFFSET_Y 0x22
>> +#define AK8974_OFFSET_Z 0x24
>> +/* AMI305-specific offsets */
>> +#define AMI305_OFFSET_X 0x6C
>> +#define AMI305_OFFSET_Y 0x72
>> +#define AMI305_OFFSET_Z 0x78
>> +
>> +/* Different temperature registers */
>> +#define AK8974_TEMP 0x31
>> +#define AMI305_TEMP 0x60
>> +
>> +#define AK8974_INT_X_HIGH BIT(7) /* Axis over +threshold */
>> +#define AK8974_INT_Y_HIGH BIT(6)
>> +#define AK8974_INT_Z_HIGH BIT(5)
>> +#define AK8974_INT_X_LOW BIT(4) /* Axis below -threshold */
>> +#define AK8974_INT_Y_LOW BIT(3)
>> +#define AK8974_INT_Z_LOW BIT(2)
>> +#define AK8974_INT_RANGE BIT(1) /* Range overflow (any axis) */
>> +
>> +#define AK8974_STATUS_DRDY BIT(6) /* Data ready */
>> +#define AK8974_STATUS_OVERRUN BIT(5) /* Data overrun */
>> +#define AK8974_STATUS_INT BIT(4) /* Interrupt occurred */
>> +
>> +#define AK8974_CTRL1_POWER BIT(7) /* 0 = standby; 1 = active */
>> +#define AK8974_CTRL1_RATE BIT(4) /* 0 = 10 Hz; 1 = 20 Hz */
>> +#define AK8974_CTRL1_FORCE_EN BIT(1) /* 0 = normal; 1 = force */
>> +#define AK8974_CTRL1_MODE2 BIT(0) /* 0 */
>> +
>> +#define AK8974_CTRL2_INT_EN BIT(4) /* 1 = enable interrupts */
>> +#define AK8974_CTRL2_DRDY_EN BIT(3) /* 1 = enable data ready signal */
>> +#define AK8974_CTRL2_DRDY_POL BIT(2) /* 1 = data ready active high */
>> +#define AK8974_CTRL2_RESDEF (AK8974_CTRL2_DRDY_POL)
>> +
>> +#define AK8974_CTRL3_RESET BIT(7) /* Software reset */
>> +#define AK8974_CTRL3_FORCE BIT(6) /* Start forced measurement */
>> +#define AK8974_CTRL3_SELFTEST BIT(4) /* Set selftest register */
>> +#define AK8974_CTRL3_RESDEF 0x00
>> +
>> +#define AK8974_INT_CTRL_XEN BIT(7) /* Enable interrupt for this axis */
>> +#define AK8974_INT_CTRL_YEN BIT(6)
>> +#define AK8974_INT_CTRL_ZEN BIT(5)
>> +#define AK8974_INT_CTRL_XYZEN (BIT(7)|BIT(6)|BIT(5))
>> +#define AK8974_INT_CTRL_POL BIT(3) /* 0 = active low; 1 = active high */
>> +#define AK8974_INT_CTRL_PULSE BIT(1) /* 0 = latched; 1 = pulse (50 usec) */
>> +#define AK8974_INT_CTRL_RESDEF (AK8974_INT_CTRL_XYZEN | AK8974_INT_CTRL_POL)
>> +
>> +/* The AMI305 has elaborate FW version and serial number registers */
>> +#define AMI305_VER 0xE8
>> +#define AMI305_SN 0xEA
>> +
>> +#define AK8974_MAX_RANGE 2048
>> +
>> +#define AK8974_POWERON_DELAY 50
>> +#define AK8974_ACTIVATE_DELAY 1
>> +#define AK8974_SELFTEST_DELAY 1
>> +/*
>> + * Set the autosuspend to two orders of magnitude larger than the poweron
>> + * delay to make sake reasonable power tradeoff savings (5 seconds in
>> + * this case).
>> + */
>> +#define AK8974_AUTOSUSPEND_DELAY 5000
>> +
>> +#define AK8974_MEASTIME 3
>> +
>> +#define AK8974_PWR_ON 1
>> +#define AK8974_PWR_OFF 0
>> +
>> +/**
>> + * struct ak8974 - state container for the AK8974 driver
>> + * @i2c: parent I2C client
>> + * @orientation: mounting matrix, flipped axis etc
>> + * @map: regmap to access the AK8974 registers over I2C
>> + * @regs: the avdd and dvdd power regulators
>> + * @name: the name of the part
>> + * @variant: the whoami ID value (for selecting code paths)
>> + * @lock: locks the magnetometer for exclusive use during a measurement
>> + * @drdy_irq: uses the DRDY IRQ line
>> + * @drdy_complete: completion for DRDY
>> + * @drdy_active_low: the DRDY IRQ is active low
>> + */
>> +struct ak8974 {
>> + struct i2c_client *i2c;
>> + struct iio_mount_matrix orientation;
>> + struct regmap *map;
>> + struct regulator_bulk_data regs[2];
>> + const char *name;
>> + u8 variant;
>> + struct mutex lock;
>> + bool drdy_irq;
>> + struct completion drdy_complete;
>> + bool drdy_active_low;
>> +};
>> +
>> +static const char ak8974_reg_avdd[] = "avdd";
>> +static const char ak8974_reg_dvdd[] = "dvdd";
>> +
>> +static int ak8974_set_power(struct ak8974 *ak8974, bool mode)
>> +{
>> + int ret;
>> + u8 val;
>> +
>> + val = mode ? AK8974_CTRL1_POWER : 0;
>> + val |= AK8974_CTRL1_FORCE_EN;
>> + ret = regmap_write(ak8974->map, AK8974_CTRL1, val);
>> + if (ret < 0)
>> + return ret;
>> +
>> + if (mode)
>> + msleep(AK8974_ACTIVATE_DELAY);
>> +
>> + return 0;
>> +}
>> +
>> +static int ak8974_reset(struct ak8974 *ak8974)
>> +{
>> + int ret;
>> +
>> + /* Power on to get register access. Sets CTRL1 reg to reset state */
>> + ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
>> + if (ret)
>> + return ret;
>> + ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_RESDEF);
>> + if (ret)
>> + return ret;
>> + ret = regmap_write(ak8974->map, AK8974_CTRL3, AK8974_CTRL3_RESDEF);
>> + if (ret)
>> + return ret;
>> + ret = regmap_write(ak8974->map, AK8974_INT_CTRL,
>> + AK8974_INT_CTRL_RESDEF);
>> + if (ret)
>> + return ret;
>> +
>> + /* After reset, power off is default state */
>> + return ak8974_set_power(ak8974, AK8974_PWR_OFF);
>> +}
>> +
>> +static int ak8974_configure(struct ak8974 *ak8974)
>> +{
>> + int ret;
>> +
>> + ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_DRDY_EN |
>> + AK8974_CTRL2_INT_EN);
>> + if (ret)
>> + return ret;
>> + ret = regmap_write(ak8974->map, AK8974_CTRL3, 0);
>> + if (ret)
>> + return ret;
>> + ret = regmap_write(ak8974->map, AK8974_INT_CTRL, AK8974_INT_CTRL_POL);
>> + if (ret)
>> + return ret;
>> +
>> + return regmap_write(ak8974->map, AK8974_PRESET, 0);
>> +}
>> +
>> +static int ak8974_trigmeas(struct ak8974 *ak8974)
>> +{
>> + unsigned int clear;
>> + u8 mask;
>> + u8 val;
>> + int ret;
>> +
>> + /* Clear any previous measurement overflow status */
>> + ret = regmap_read(ak8974->map, AK8974_INT_CLEAR, &clear);
>> + if (ret)
>> + return ret;
>> +
>> + /* If we have a DRDY IRQ line, use it */
>> + if (ak8974->drdy_irq) {
>> + mask = AK8974_CTRL2_INT_EN |
>> + AK8974_CTRL2_DRDY_EN |
>> + AK8974_CTRL2_DRDY_POL;
>> + val = AK8974_CTRL2_DRDY_EN;
>> +
>> + if (!ak8974->drdy_active_low)
>> + val |= AK8974_CTRL2_DRDY_POL;
>> +
>> + init_completion(&ak8974->drdy_complete);
>> + ret = regmap_update_bits(ak8974->map, AK8974_CTRL2,
>> + mask, val);
>> + if (ret)
>> + return ret;
>> + }
>> +
>> + /* Force a measurement */
>> + return regmap_update_bits(ak8974->map,
>> + AK8974_CTRL3,
>> + AK8974_CTRL3_FORCE,
>> + AK8974_CTRL3_FORCE);
>> +}
>> +
>> +static int ak8974_await_drdy(struct ak8974 *ak8974)
>> +{
>> + int timeout = 2;
>> + unsigned int val;
>> + int ret;
>> +
>> + if (ak8974->drdy_irq) {
>> + ret = wait_for_completion_timeout(&ak8974->drdy_complete,
>> + 1 + msecs_to_jiffies(1000));
>> + if (!ret) {
>> + dev_err(&ak8974->i2c->dev,
>> + "timeout waiting for DRDY IRQ\n");
>> + return -ETIMEDOUT;
>> + }
>> + return 0;
>> + }
>> +
>> + /* Default delay-based poll loop */
>> + do {
>> + msleep(AK8974_MEASTIME);
>> + ret = regmap_read(ak8974->map, AK8974_STATUS, &val);
>> + if (ret < 0)
>> + return ret;
>> + if (val & AK8974_STATUS_DRDY)
>> + return 0;
>> + } while (--timeout);
>> + if (!timeout) {
>> + dev_err(&ak8974->i2c->dev,
>> + "timeout waiting for DRDY\n");
>> + return -ETIMEDOUT;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int ak8974_getresult(struct ak8974 *ak8974, s16 *result)
>> +{
>> + unsigned int src;
>> + int ret;
>> + int i;
>> +
>> + ret = ak8974_await_drdy(ak8974);
>> + if (ret)
>> + return ret;
>> + ret = regmap_read(ak8974->map, AK8974_INT_SRC, &src);
>> + if (ret < 0)
>> + return ret;
>> +
>> + /* Out of range overflow! Strong magnet close? */
>> + if (src & AK8974_INT_RANGE) {
>> + dev_err(&ak8974->i2c->dev,
>> + "range overflow in sensor\n");
>> + return -ERANGE;
>> + }
>> +
>> + ret = regmap_bulk_read(ak8974->map, AK8974_DATA_X, result, 6);
>> + if (ret)
>> + return ret;
>> + for (i = 0; i < 3; i++)
>> + result[i] = le16_to_cpu(result[i]);
>> +
>> + return ret;
>> +}
>> +
>> +static irqreturn_t ak8974_drdy_irq(int irq, void *d)
>> +{
>> + struct ak8974 *ak8974 = d;
>> +
>> + if (!ak8974->drdy_irq)
>> + return IRQ_NONE;
>> +
>> + /* TODO: timestamp here to get good measurement stamps */
>> + return IRQ_WAKE_THREAD;
>> +}
>> +
>> +static irqreturn_t ak8974_drdy_irq_thread(int irq, void *d)
>> +{
>> + struct ak8974 *ak8974 = d;
>> + unsigned int val;
>> + int ret;
>> +
>> + /* Check if this was a DRDY from us */
>> + ret = regmap_read(ak8974->map, AK8974_STATUS, &val);
>> + if (ret < 0) {
>> + dev_err(&ak8974->i2c->dev, "error reading DRDY status\n");
>> + return IRQ_HANDLED;
>> + }
>> + if (val & AK8974_STATUS_DRDY) {
>> + /* Yes this was our IRQ */
>> + complete(&ak8974->drdy_complete);
>> + return IRQ_HANDLED;
>> + }
>> +
>> + /* We may be on a shared IRQ, let the next client check */
>> + return IRQ_NONE;
>> +}
>> +
>> +static int ak8974_selftest(struct ak8974 *ak8974)
>> +{
>> + struct device *dev = &ak8974->i2c->dev;
>> + unsigned int val;
>> + int ret;
>> +
>> + ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
>> + if (ret)
>> + return ret;
>> + if (val != AK8974_SELFTEST_IDLE) {
>> + dev_err(dev, "selftest not idle before test\n");
>> + return -EIO;
>> + }
>> +
>> + /* Trigger self-test */
>> + ret = regmap_update_bits(ak8974->map,
>> + AK8974_CTRL3,
>> + AK8974_CTRL3_SELFTEST,
>> + AK8974_CTRL3_SELFTEST);
>> + if (ret) {
>> + dev_err(dev, "could not write CTRL3\n");
>> + return ret;
>> + }
>> +
>> + msleep(AK8974_SELFTEST_DELAY);
>> +
>> + ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
>> + if (ret)
>> + return ret;
>> + if (val != AK8974_SELFTEST_OK) {
>> + dev_err(dev, "selftest result NOT OK (%02x)\n", val);
>> + return -EIO;
>> + }
>> +
>> + ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
>> + if (ret)
>> + return ret;
>> + if (val != AK8974_SELFTEST_IDLE) {
>> + dev_err(dev, "selftest not idle after test (%02x)\n", val);
>> + return -EIO;
>> + }
>> + dev_dbg(dev, "passed self-test\n");
>> +
>> + return 0;
>> +}
>> +
>> +static int ak8974_get_u16_val(struct ak8974 *ak8974, u8 reg, u16 *val)
>> +{
>> + int ret;
>> + u16 bulk;
>> +
>> + ret = regmap_bulk_read(ak8974->map, reg, &bulk, 2);
>> + if (ret)
>> + return ret;
>> + *val = le16_to_cpu(bulk);
>> +
>> + return 0;
>> +}
>> +
>> +static int ak8974_detect(struct ak8974 *ak8974)
>> +{
>> + unsigned int whoami;
>> + const char *name;
>> + int ret;
>> + unsigned int fw;
>> + u16 sn;
>> +
>> + ret = regmap_read(ak8974->map, AK8974_WHOAMI, &whoami);
>> + if (ret)
>> + return ret;
>> +
>> + switch (whoami) {
>> + case AK8974_WHOAMI_VALUE_AMI305:
>> + name = "ami305";
>> + ret = regmap_read(ak8974->map, AMI305_VER, &fw);
>> + if (ret)
>> + return ret;
>> + fw &= 0x7f; /* only bits 0 thru 6 valid */
>> + ret = ak8974_get_u16_val(ak8974, AMI305_SN, &sn);
>> + if (ret)
>> + return ret;
>> + dev_info(&ak8974->i2c->dev,
>> + "detected %s, FW ver %02x, S/N: %04x\n",
>> + name, fw, sn);
>> + break;
>> + case AK8974_WHOAMI_VALUE_AK8974:
>> + name = "ak8974";
>> + dev_info(&ak8974->i2c->dev, "detected AK8974\n");
>> + break;
>> + default:
>> + dev_err(&ak8974->i2c->dev, "unsupported device (%02x) ",
>> + whoami);
>> + return -ENODEV;
>> + }
>> +
>> + ak8974->name = name;
>> + ak8974->variant = whoami;
>> +
>> + return 0;
>> +}
>> +
>> +static int ak8974_read_raw(struct iio_dev *indio_dev,
>> + struct iio_chan_spec const *chan,
>> + int *val, int *val2,
>> + long mask)
>> +{
>> + struct ak8974 *ak8974 = iio_priv(indio_dev);
>> + s16 hw_values[3];
>> + int ret = -EINVAL;
>> +
>> + pm_runtime_get_sync(&ak8974->i2c->dev);
>> + mutex_lock(&ak8974->lock);
>> +
>> + switch (mask) {
>> + case IIO_CHAN_INFO_RAW:
>> + if (chan->address > 2) {
>> + dev_err(&ak8974->i2c->dev, "faulty channel address\n");
>> + ret = -EIO;
>> + goto out_unlock;
>> + }
>> + ret = ak8974_trigmeas(ak8974);
>> + if (ret) {
>> + return ret;
>> + goto out_unlock;
>> + }
>> + ret = ak8974_getresult(ak8974, hw_values);
>> + if (ret) {
>> + return ret;
>> + goto out_unlock;
>> + }
>> +
>> + /*
>> + * We read all axes and discard all but one, for optimized
>> + * reading, use the triggered buffer.
>> + */
>> + *val = hw_values[chan->address];
>> +
>> + ret = IIO_VAL_INT;
>> + }
>> +
>> + out_unlock:
>> + mutex_unlock(&ak8974->lock);
>> + pm_runtime_mark_last_busy(&ak8974->i2c->dev);
>> + pm_runtime_put_autosuspend(&ak8974->i2c->dev);
>> +
>> + return ret;
>> +}
>> +
>> +static void ak8974_fill_buffer(struct iio_dev *indio_dev)
>> +{
>> + struct ak8974 *ak8974 = iio_priv(indio_dev);
>> + int ret;
>> + s16 hw_values[8]; /* Three axes + 64bit padding */
>> +
>> + pm_runtime_get_sync(&ak8974->i2c->dev);
>> + mutex_lock(&ak8974->lock);
>> +
>> + ret = ak8974_trigmeas(ak8974);
>> + if (ret) {
>> + dev_err(&ak8974->i2c->dev, "error triggering measure\n");
>> + goto out_unlock;
>> + }
>> + ret = ak8974_getresult(ak8974, hw_values);
>> + if (ret) {
>> + dev_err(&ak8974->i2c->dev, "error getting measures\n");
>> + goto out_unlock;
>> + }
>> +
>> + iio_push_to_buffers_with_timestamp(indio_dev, hw_values,
>> + iio_get_time_ns());
>> +
>> + out_unlock:
>> + mutex_unlock(&ak8974->lock);
>> + pm_runtime_mark_last_busy(&ak8974->i2c->dev);
>> + pm_runtime_put_autosuspend(&ak8974->i2c->dev);
>> +}
>> +
>> +static irqreturn_t ak8974_handle_trigger(int irq, void *p)
>> +{
>> + const struct iio_poll_func *pf = p;
>> + struct iio_dev *indio_dev = pf->indio_dev;
>> +
>> + ak8974_fill_buffer(indio_dev);
>> + iio_trigger_notify_done(indio_dev->trig);
>> +
>> + return IRQ_HANDLED;
>> +}
>> +
>> +static const struct iio_mount_matrix *
>> +ak8974_get_mount_matrix(const struct iio_dev *indio_dev,
>> + const struct iio_chan_spec *chan)
>> +{
>> + struct ak8974 *ak8974 = iio_priv(indio_dev);
>> +
>> + return &ak8974->orientation;
>> +}
>> +
>> +static const struct iio_chan_spec_ext_info ak8974_ext_info[] = {
>> + IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8974_get_mount_matrix),
>> + { },
>> +};
>> +
>> +#define AK8974_AXIS_CHANNEL(axis, index) \
>> + { \
>> + .type = IIO_MAGN, \
>> + .modified = 1, \
>> + .channel2 = IIO_MOD_##axis, \
>> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
>> + .ext_info = ak8974_ext_info, \
>> + .address = index, \
>> + .scan_index = index, \
>> + .scan_type = { \
>> + .sign = 's', \
>> + .realbits = 16, \
>> + .storagebits = 16, \
>> + .endianness = IIO_CPU \
>> + }, \
>> + }
>> +
>> +static const struct iio_chan_spec ak8974_channels[] = {
>> + AK8974_AXIS_CHANNEL(X, 0),
>> + AK8974_AXIS_CHANNEL(Y, 1),
>> + AK8974_AXIS_CHANNEL(Z, 2),
>> + IIO_CHAN_SOFT_TIMESTAMP(3),
>> +};
>> +
>> +static const unsigned long ak8974_scan_masks[] = { 0x7, 0 };
>> +
>> +static const struct iio_info ak8974_info = {
>> + .read_raw = &ak8974_read_raw,
>> + .driver_module = THIS_MODULE,
>> +};
>> +
>> +static bool ak8974_writeable_reg(struct device *dev, unsigned int reg)
>> +{
>> + struct i2c_client *i2c = to_i2c_client(dev);
>> + struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
>> + struct ak8974 *ak8974 = iio_priv(indio_dev);
>> +
>> + switch (reg) {
>> + case AK8974_CTRL1:
>> + case AK8974_CTRL2:
>> + case AK8974_CTRL3:
>> + case AK8974_INT_CTRL:
>> + case AK8974_INT_THRES:
>> + case AK8974_INT_THRES + 1:
>> + case AK8974_PRESET:
>> + case AK8974_PRESET + 1:
>> + return true;
>> + case AK8974_OFFSET_X:
>> + case AK8974_OFFSET_X + 1:
>> + case AK8974_OFFSET_Y:
>> + case AK8974_OFFSET_Y + 1:
>> + case AK8974_OFFSET_Z:
>> + case AK8974_OFFSET_Z + 1:
>> + if (ak8974->variant == AK8974_WHOAMI_VALUE_AK8974)
>> + return true;
>> + return false;
>> + case AMI305_OFFSET_X:
>> + case AMI305_OFFSET_X + 1:
>> + case AMI305_OFFSET_Y:
>> + case AMI305_OFFSET_Y + 1:
>> + case AMI305_OFFSET_Z:
>> + case AMI305_OFFSET_Z + 1:
>> + if (ak8974->variant == AK8974_WHOAMI_VALUE_AMI305)
>> + return true;
>> + return false;
>> + default:
>> + break;
>> + }
>> + return false;
>> +}
>> +
>> +static const struct regmap_config ak8974_regmap_config = {
>> + .reg_bits = 8,
>> + .val_bits = 8,
>> + .max_register = 0xff,
>> + .writeable_reg = ak8974_writeable_reg,
>> +};
>> +
>> +static int ak8974_probe(struct i2c_client *i2c,
>> + const struct i2c_device_id *id)
>> +{
>> + struct iio_dev *indio_dev;
>> + struct ak8974 *ak8974;
>> + unsigned long irq_trig;
>> + int irq = i2c->irq;
>> + int ret;
>> +
>> + /* Register with IIO */
>> + indio_dev = devm_iio_device_alloc(&i2c->dev, sizeof(*ak8974));
>> + if (indio_dev == NULL)
>> + return -ENOMEM;
>> +
>> + ak8974 = iio_priv(indio_dev);
>> + i2c_set_clientdata(i2c, indio_dev);
>> + ak8974->i2c = i2c;
>> + mutex_init(&ak8974->lock);
>> +
>> + ret = of_iio_read_mount_matrix(&i2c->dev,
>> + "mount-matrix",
>> + &ak8974->orientation);
>> + if (ret)
>> + return ret;
>> +
>> + ak8974->regs[0].supply = ak8974_reg_avdd;
>> + ak8974->regs[1].supply = ak8974_reg_dvdd;
>> +
>> + ret = devm_regulator_bulk_get(&i2c->dev,
>> + ARRAY_SIZE(ak8974->regs),
>> + ak8974->regs);
>> + if (ret < 0) {
>> + dev_err(&i2c->dev, "Cannot get regulators\n");
>> + return ret;
>> + }
>> +
>> + ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
>> + if (ret < 0) {
>> + dev_err(&i2c->dev, "Cannot enable regulators\n");
>> + return ret;
>> + }
>> +
>> + /* Take runtime PM online */
>> + pm_runtime_get_noresume(&i2c->dev);
>> + pm_runtime_set_active(&i2c->dev);
>> + pm_runtime_enable(&i2c->dev);
>> +
>> + ak8974->map = devm_regmap_init_i2c(i2c, &ak8974_regmap_config);
>> + if (IS_ERR(ak8974->map)) {
>> + dev_err(&i2c->dev, "failed to allocate register map\n");
>> + return PTR_ERR(ak8974->map);
>> + }
>> +
>> + ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
>> + if (ret) {
>> + dev_err(&i2c->dev, "could not power on\n");
>> + goto power_off;
>> + }
>> +
>> + ret = ak8974_detect(ak8974);
>> + if (ret) {
>> + dev_err(&i2c->dev, "neither AK8974 nor AMI305 found\n");
>> + goto power_off;
>> + }
>> +
>> + ret = ak8974_selftest(ak8974);
>> + if (ret)
>> + dev_err(&i2c->dev, "selftest failed (continuing anyway)\n");
>> +
>> + ret = ak8974_reset(ak8974);
>> + if (ret) {
>> + dev_err(&i2c->dev, "AK8974 reset failed");
>> + goto power_off;
>> + }
>> +
>> + pm_runtime_set_autosuspend_delay(&i2c->dev,
>> + AK8974_AUTOSUSPEND_DELAY);
>> + pm_runtime_use_autosuspend(&i2c->dev);
>> + pm_runtime_put(&i2c->dev);
>> +
>> + indio_dev->dev.parent = &i2c->dev;
>> + indio_dev->channels = ak8974_channels;
>> + indio_dev->num_channels = ARRAY_SIZE(ak8974_channels);
>> + indio_dev->info = &ak8974_info;
>> + indio_dev->available_scan_masks = ak8974_scan_masks;
>> + indio_dev->modes = INDIO_DIRECT_MODE;
>> + indio_dev->name = ak8974->name;
>> +
>> + ret = iio_triggered_buffer_setup(indio_dev, NULL,
>> + ak8974_handle_trigger,
>> + NULL);
>> + if (ret) {
>> + dev_err(&i2c->dev, "triggered buffer setup failed\n");
>> + goto disable_pm;
>> + }
>> +
>> + /* If we have a valid DRDY IRQ, make use of it */
>> + if (irq > 0) {
>> + irq_trig = irqd_get_trigger_type(irq_get_irq_data(irq));
>> + if (irq_trig == IRQF_TRIGGER_RISING) {
>> + dev_info(&i2c->dev, "enable rising edge DRDY IRQ\n");
>> + } else if (irq_trig == IRQF_TRIGGER_FALLING) {
>> + ak8974->drdy_active_low = true;
>> + dev_info(&i2c->dev, "enable falling edge DRDY IRQ\n");
>> + } else {
>> + irq_trig = IRQF_TRIGGER_RISING;
>> + }
>> + irq_trig |= IRQF_ONESHOT;
>> + irq_trig |= IRQF_SHARED;
>> +
>> + ret = devm_request_threaded_irq(&i2c->dev,
>> + irq,
>> + ak8974_drdy_irq,
>> + ak8974_drdy_irq_thread,
>> + irq_trig,
>> + ak8974->name,
>> + ak8974);
>> + if (ret) {
>> + dev_err(&i2c->dev, "unable to request DRDY IRQ "
>> + "- proceeding without IRQ\n");
>> + goto no_irq;
>> + }
>> + ak8974->drdy_irq = true;
>> + }
>> +
>> +no_irq:
>> + ret = iio_device_register(indio_dev);
>> + if (ret) {
>> + dev_err(&i2c->dev, "device register failed\n");
>> + goto cleanup_buffer;
>> + }
>> +
>> + return 0;
>> +
>> +cleanup_buffer:
>> + iio_triggered_buffer_cleanup(indio_dev);
>> +disable_pm:
>> + pm_runtime_put_noidle(&i2c->dev);
>> + pm_runtime_disable(&i2c->dev);
>> + ak8974_set_power(ak8974, AK8974_PWR_OFF);
>> +power_off:
>> + regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
>> +
>> + return ret;
>> +}
>> +
>> +static int __exit ak8974_remove(struct i2c_client *i2c)
>> +{
>> + struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
>> + struct ak8974 *ak8974 = iio_priv(indio_dev);
>> +
>> + iio_device_unregister(indio_dev);
>> + iio_triggered_buffer_cleanup(indio_dev);
>> + pm_runtime_get_sync(&i2c->dev);
>> + pm_runtime_put_noidle(&i2c->dev);
>> + pm_runtime_disable(&i2c->dev);
>> + ak8974_set_power(ak8974, AK8974_PWR_OFF);
>> + regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
>> +
>> + return 0;
>> +}
>> +
>> +#ifdef CONFIG_PM
>> +static int ak8974_runtime_suspend(struct device *dev)
>> +{
>> + struct ak8974 *ak8974 =
>> + iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
>> +
>> + ak8974_set_power(ak8974, AK8974_PWR_OFF);
>> + regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
>> +
>> + return 0;
>> +}
>> +
>> +static int ak8974_runtime_resume(struct device *dev)
>> +{
>> + struct ak8974 *ak8974 =
>> + iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
>> + int ret;
>> +
>> + ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
>> + if (ret)
>> + return ret;
>> + msleep(AK8974_POWERON_DELAY);
>> + ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
>> + if (ret)
>> + goto out_regulator_disable;
>> +
>> + ret = ak8974_configure(ak8974);
>> + if (ret)
>> + goto out_disable_power;
>> +
>> + return 0;
>> +
>> +out_disable_power:
>> + ak8974_set_power(ak8974, AK8974_PWR_OFF);
>> +out_regulator_disable:
>> + regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
>> +
>> + return ret;
>> +}
>> +#endif /* CONFIG_PM */
>> +
>> +static const struct dev_pm_ops ak8974_dev_pm_ops = {
>> + SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
>> + pm_runtime_force_resume)
>> + SET_RUNTIME_PM_OPS(ak8974_runtime_suspend,
>> + ak8974_runtime_resume, NULL)
>> +};
>> +
>> +static const struct i2c_device_id ak8974_id[] = {
>> + {"ami305", 0 },
>> + {"ak8974", 0 },
>> + {}
>> +};
>> +MODULE_DEVICE_TABLE(i2c, ak8974_id);
>> +
>> +static const struct of_device_id ak8974_of_match[] = {
>> + { .compatible = "asahi-kasei,ak8974", },
>> + {}
>> +};
>> +MODULE_DEVICE_TABLE(of, ak8974_of_match);
>> +
>> +static struct i2c_driver ak8974_driver = {
>> + .driver = {
>> + .name = "ak8974",
>> + .owner = THIS_MODULE,
>> + .pm = &ak8974_dev_pm_ops,
>> + .of_match_table = of_match_ptr(ak8974_of_match),
>> + },
>> + .probe = ak8974_probe,
>> + .remove = __exit_p(ak8974_remove),
>> + .id_table = ak8974_id,
>> +};
>> +module_i2c_driver(ak8974_driver);
>> +
>> +MODULE_DESCRIPTION("AK8974 and AMI305 3-axis magnetometer driver");
>> +MODULE_AUTHOR("Samu Onkalo");
>> +MODULE_AUTHOR("Linus Walleij");
>> +MODULE_LICENSE("GPL v2");
>>
>
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