On 18/03/17 13:34, Linus Walleij wrote:
> The Qualcomm PM8xxx PMICs contain a simpler ADC than its
> successors (already in the kernel as qcom-spmi-vadc.c):
> the HK/XO ADC (Housekeeping/Chrystal oscillator ADC).
>
> As far as I can understand this is equal to the PMICs
> using SSBI transport and encompass PM8018, PM8038,
> PM8058, and PM8921, so this is shortly named PM8xxx.
>
> This ADC monitors a bunch of on-board voltages and the die
> temperature of the PMIC itself, but it can also be routed
> to convert a few external MPPs (multi-purpose pins). On
> the APQ8060 DragonBoard this feature is used to let this
> ADC convert an analog ALS (Ambient Light Sensor) voltage
> signal from a Capella CM3605 ALS into a LUX value.
>
> Developed and tested with APQ8060 DragonBoard based on
> Ivan's driver and Rama Krishna's patches. The SPMI VADC
> driver is quite different, but share enough minor
> functionality that I have split out to the common file
> in a previous patch.
>
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Cc: linux-arm-msm@xxxxxxxxxxxxxxx
> Cc: Ivan T. Ivanov <iivanov.xz@xxxxxxxxx>
> Cc: Andy Gross <andy.gross@xxxxxxxxxx>
> Cc: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> Cc: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
> Cc: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> Cc: Rama Krishna Phani A <rphani@xxxxxxxxxxxxxx>
> Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
A few little bits inline. Always find something new when rereading :)
Otherwise, looks fine and that mux stuff seems to make sense.
Jonathan
> ---
> ChangeLog v4->v5:
> - Fix the kbuild for allmod and allyes as described earlier.
> - Add a per-variant information container instead of just adding
> a list of channels to the match data. Use this variant
> information throughout the code to support the variations.
> - Incorporate new information from Björn and Stephen about how the
> channels actually work on the different variants. PM8058 has 16
> channels that can be muxed to different sources, so an AMUX
> setting each. The PM8921 is more complex because it has a premux
> instead of a prescaler.
> - To deal with the premux addressing scheme we turn all channel
> specifiers into twocell, where the first cell is prescaler or
> premux and the second one is the analog mux.
> - Rebase on build fixes.
> ChangeLog v3->v4:
> - Only reposting this patch as the DT bindings and refactorings
> are merged.
> - Prefix all channel names with PM8XXX_* to avoid namespace clashes.
> - Use the compatible string to name the IIO device for greater
> model precision.
> - Fix up a few excess newlines.
> ChangeLog v2->v3:
> - Rebase using Rama Krishna's improvements, set up defaults for
> scaling function and prescaler for each channel, per ASIC variant.
> - Also set up RSV per-variant as the vendor tree does this and
> it seems necessary to set RSV0 on the muxoff channel to get
> readings from the XO thermistor.
> - Encode default IIO type in the default per-PMIC channel table.
> - Fixed a bug in ratiometric calibration (needed to force ratiometric
> mode).
> - Dropped PM8917: that doesn't have any XOADC.
> - Added a special flag for the PM8058: it apparently needs special
> RSV muxing due to being necessarily different.
> - Augmented to handle altered ratiometric DT property.
> - Do not hardcode that the reference voltage must be 2.2V, just fetch
> and enable the regulator. Different PMICs use different reference
> voltages.
> ChangeLog v1->v2:
> - Introduce a mutex to avoid different clients stepping on each others'
> toes
> - Add an of_xlate function to be sure to match the right ADC
> - Add all compatible strings, not just PM8058
> ---
> drivers/iio/adc/Kconfig | 11 +
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/qcom-pm8xxx-xoadc.c | 1036 +++++++++++++++++++++++++++++++++++
> 3 files changed, 1048 insertions(+)
> create mode 100644 drivers/iio/adc/qcom-pm8xxx-xoadc.c
>
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 8720e1c706fe..24c97add7f2f 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -445,6 +445,17 @@ config PALMAS_GPADC
> config QCOM_VADC_COMMON
> tristate
>
> +config QCOM_PM8XXX_XOADC
> + tristate "Qualcomm SSBI PM8xxx PMIC XOADCs"
> + depends on MFD_PM8XXX
> + select QCOM_VADC_COMMON
> + help
> + ADC driver for the XOADC portions of the Qualcomm PM8xxx PMICs
> + using SSBI transport: PM8018, PM8038, PM8058, PM8921.
> +
> + To compile this driver as a module, choose M here: the module
> + will be called qcom-pm8xxx-xoadc.
> +
> config QCOM_SPMI_IADC
> tristate "Qualcomm SPMI PMIC current ADC"
> depends on SPMI
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index 8c2e294042ae..0394bc740bdc 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -45,6 +45,7 @@ obj-$(CONFIG_PALMAS_GPADC) += palmas_gpadc.o
> obj-$(CONFIG_QCOM_SPMI_IADC) += qcom-spmi-iadc.o
> obj-$(CONFIG_QCOM_VADC_COMMON) += qcom-vadc-common.o
> obj-$(CONFIG_QCOM_SPMI_VADC) += qcom-spmi-vadc.o
> +obj-$(CONFIG_QCOM_PM8XXX_XOADC) += qcom-pm8xxx-xoadc.o
> obj-$(CONFIG_RCAR_GYRO_ADC) += rcar-gyroadc.o
> obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o
> obj-$(CONFIG_STX104) += stx104.o
> diff --git a/drivers/iio/adc/qcom-pm8xxx-xoadc.c b/drivers/iio/adc/qcom-pm8xxx-xoadc.c
> new file mode 100644
> index 000000000000..cea8f1fb444a
> --- /dev/null
> +++ b/drivers/iio/adc/qcom-pm8xxx-xoadc.c
> @@ -0,0 +1,1036 @@
> +/*
> + * Qualcomm PM8xxx PMIC XOADC driver
> + *
> + * These ADCs are known as HK/XO (house keeping / chrystal oscillator)
> + * "XO" in "XOADC" means Chrystal Oscillator. It's a bunch of
> + * specific-purpose and general purpose ADC converters and channels.
> + *
> + * Copyright (C) 2017 Linaro Ltd.
> + * Author: Linus Walleij <linus.walleij@xxxxxxxxxx>
> + */
> +
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/regulator/consumer.h>
> +
> +#include "qcom-vadc-common.h"
> +
> +/*
> + * Definitions for the "user processor" registers lifted from the v3.4
> + * Qualcomm tree. Their kernel has two out-of-tree drivers for the ADC:
> + * drivers/misc/pmic8058-xoadc.c
> + * drivers/hwmon/pm8xxx-adc.c
> + * None of them contain any complete register specification, so this is
> + * a best effort of combining the information.
> + */
> +
> +/* These appear to be "battery monitor" registers */
> +#define ADC_ARB_BTM_CNTRL1 0x17e
> +#define ADC_ARB_BTM_CNTRL1_EN_BTM BIT(0)
> +#define ADC_ARB_BTM_CNTRL1_SEL_OP_MODE BIT(1)
> +#define ADC_ARB_BTM_CNTRL1_MEAS_INTERVAL1 BIT(2)
> +#define ADC_ARB_BTM_CNTRL1_MEAS_INTERVAL2 BIT(3)
> +#define ADC_ARB_BTM_CNTRL1_MEAS_INTERVAL3 BIT(4)
> +#define ADC_ARB_BTM_CNTRL1_MEAS_INTERVAL4 BIT(5)
> +#define ADC_ARB_BTM_CNTRL1_EOC BIT(6)
> +#define ADC_ARB_BTM_CNTRL1_REQ BIT(7)
> +
> +#define ADC_ARB_BTM_AMUX_CNTRL 0x17f
> +#define ADC_ARB_BTM_ANA_PARAM 0x180
> +#define ADC_ARB_BTM_DIG_PARAM 0x181
> +#define ADC_ARB_BTM_RSV 0x182
> +#define ADC_ARB_BTM_DATA1 0x183
> +#define ADC_ARB_BTM_DATA0 0x184
> +#define ADC_ARB_BTM_BAT_COOL_THR1 0x185
> +#define ADC_ARB_BTM_BAT_COOL_THR0 0x186
> +#define ADC_ARB_BTM_BAT_WARM_THR1 0x187
> +#define ADC_ARB_BTM_BAT_WARM_THR0 0x188
> +#define ADC_ARB_BTM_CNTRL2 0x18c
> +
> +/* Proper ADC registers */
> +
> +#define ADC_ARB_USRP_CNTRL 0x197
> +#define ADC_ARB_USRP_CNTRL_EN_ARB BIT(0)
> +#define ADC_ARB_USRP_CNTRL_RSV1 BIT(1)
> +#define ADC_ARB_USRP_CNTRL_RSV2 BIT(2)
> +#define ADC_ARB_USRP_CNTRL_RSV3 BIT(3)
> +#define ADC_ARB_USRP_CNTRL_RSV4 BIT(4)
> +#define ADC_ARB_USRP_CNTRL_RSV5 BIT(5)
> +#define ADC_ARB_USRP_CNTRL_EOC BIT(6)
> +#define ADC_ARB_USRP_CNTRL_REQ BIT(7)
> +
> +#define ADC_ARB_USRP_AMUX_CNTRL 0x198
> +/*
> + * The channel mask includes the bits selecting channel mux and prescaler
> + * on PM8058, or channel mux and premux on PM8921.
> + */
> +#define ADC_ARB_USRP_AMUX_CNTRL_CHAN_MASK 0xfc
> +#define ADC_ARB_USRP_AMUX_CNTRL_RSV0 BIT(0)
> +#define ADC_ARB_USRP_AMUX_CNTRL_RSV1 BIT(1)
> +/* On PM8058 this is prescaling, on PM8921 this is premux */
> +#define ADC_ARB_USRP_AMUX_CNTRL_PRESCALEMUX0 BIT(2)
> +#define ADC_ARB_USRP_AMUX_CNTRL_PRESCALEMUX1 BIT(3)
> +#define ADC_ARB_USRP_AMUX_CNTRL_SEL0 BIT(4)
> +#define ADC_ARB_USRP_AMUX_CNTRL_SEL1 BIT(5)
> +#define ADC_ARB_USRP_AMUX_CNTRL_SEL2 BIT(6)
> +#define ADC_ARB_USRP_AMUX_CNTRL_SEL3 BIT(7)
> +#define ADC_AMUX_PREMUX_SHIFT 2
> +#define ADC_AMUX_SEL_SHIFT 4
> +
> +/* We know very little about the bits in this register */
> +#define ADC_ARB_USRP_ANA_PARAM 0x199
> +#define ADC_ARB_USRP_ANA_PARAM_DIS 0xFE
> +#define ADC_ARB_USRP_ANA_PARAM_EN 0xFF
> +
> +#define ADC_ARB_USRP_DIG_PARAM 0x19A
> +#define ADC_ARB_USRP_DIG_PARAM_SEL_SHIFT0 BIT(0)
> +#define ADC_ARB_USRP_DIG_PARAM_SEL_SHIFT1 BIT(1)
> +#define ADC_ARB_USRP_DIG_PARAM_CLK_RATE0 BIT(2)
> +#define ADC_ARB_USRP_DIG_PARAM_CLK_RATE1 BIT(3)
> +#define ADC_ARB_USRP_DIG_PARAM_EOC BIT(4)
> +/*
> + * On a later ADC the decimation factors are defined as
> + * 00 = 512, 01 = 1024, 10 = 2048, 11 = 4096 so assume this
> + * holds also for this older XOADC.
> + */
> +#define ADC_ARB_USRP_DIG_PARAM_DEC_RATE0 BIT(5)
> +#define ADC_ARB_USRP_DIG_PARAM_DEC_RATE1 BIT(6)
> +#define ADC_ARB_USRP_DIG_PARAM_EN BIT(7)
> +#define ADC_DIG_PARAM_DEC_SHIFT 5
> +
> +#define ADC_ARB_USRP_RSV 0x19B
> +#define ADC_ARB_USRP_RSV_RST BIT(0)
> +#define ADC_ARB_USRP_RSV_DTEST0 BIT(1)
> +#define ADC_ARB_USRP_RSV_DTEST1 BIT(2)
> +#define ADC_ARB_USRP_RSV_OP BIT(3)
> +#define ADC_ARB_USRP_RSV_IP_SEL0 BIT(4)
> +#define ADC_ARB_USRP_RSV_IP_SEL1 BIT(5)
> +#define ADC_ARB_USRP_RSV_IP_SEL2 BIT(6)
> +#define ADC_ARB_USRP_RSV_TRM BIT(7)
> +#define ADC_RSV_IP_SEL_SHIFT 4
> +
> +#define ADC_ARB_USRP_DATA0 0x19D
> +#define ADC_ARB_USRP_DATA1 0x19C
> +
> +/**
> + * Physical channels which MUST exist on all PM variants in order to provide
> + * proper reference points for calibration.
> + *
> + * @PM8XXX_CHANNEL_INTERNAL: 625mV reference channel
> + * @PM8XXX_CHANNEL_125V: 1250mV reference channel
> + * @PM8XXX_CHANNEL_INTERNAL_2: 325mV reference channel
> + * @PM8XXX_CHANNEL_MUXOFF: channel to reduce input load on mux, apparently also
> + * measures XO temperature
> + */
> +#define PM8XXX_CHANNEL_INTERNAL 0x0c
> +#define PM8XXX_CHANNEL_125V 0x0d
> +#define PM8XXX_CHANNEL_INTERNAL_2 0x0e
> +#define PM8XXX_CHANNEL_MUXOFF 0x0f
> +
> +/*
> + * PM8058 AMUX premux scaling, two bits. This is done of the channel before
> + * reaching the AMUX.
> + */
> +#define PM8058_AMUX_PRESCALE_0 0x0 /* No scaling on the signal */
> +#define PM8058_AMUX_PRESCALE_1 0x1 /* Unity scaling selected by the user */
> +#define PM8058_AMUX_PRESCALE_1_DIV3 0x2 /* 1/3 prescaler on the input */
> +
> +/* Defines reference voltage for the XOADC */
> +#define AMUX_RSV0 0x0 /* XO_IN/XOADC_GND, special selection to read XO temp */
> +#define AMUX_RSV1 0x1 /* PMIC_IN/XOADC_GND */
> +#define AMUX_RSV2 0x2 /* PMIC_IN/BMS_CSP */
> +#define AMUX_RSV3 0x3 /* not used */
> +#define AMUX_RSV4 0x4 /* XOADC_GND/XOADC_GND */
> +#define AMUX_RSV5 0x5 /* XOADC_VREF/XOADC_GND */
> +#define XOADC_RSV_MAX 5 /* 3 bits 0..7, 3 and 6,7 are invalid */
> +
> +/**
> + * struct xoadc_channel - encodes channel properties and defaults
> + * @datasheet_name: the hardwarename of this channel
> + * @pre_scale_mux: prescale (PM8058) or premux (PM8921) for selecting
> + * this channel. Both this and the amux channel is needed to uniquely
> + * identify a channel. Values 0..3.
> + * @amux_channel: value of the ADC_ARB_USRP_AMUX_CNTRL register for this
> + * channel, bits 4..7, selects the amux, values 0..f
> + * @prescale: the channels have hard-coded prescale ratios defined
> + * by the hardware, this tells us what it is
> + * @type: corresponding IIO channel type, usually IIO_VOLTAGE or
> + * IIO_TEMP
> + * @scale_fn_type: the liner interpolation etc to convert the
> + * ADC code to the value that IIO expects, in uV or millicelsius
> + * etc. This scale function can be pretty elaborate if different
> + * thermistors are connected or other hardware characteristics are
> + * deployed.
> + * @amux_ip_rsv: ratiometric scale value used by the analog muxer: this
> + * selects the reference voltage for ratiometric scaling
> + */
> +struct xoadc_channel {
> + const char *datasheet_name;
> + u8 pre_scale_mux:2;
> + u8 amux_channel:4;
> + const struct vadc_prescale_ratio prescale;
> + enum iio_chan_type type;
> + enum vadc_scale_fn_type scale_fn_type;
> + u8 amux_ip_rsv:3;
> +};
> +
> +/**
> + * struct xoadc_variant - encodes the XOADC variant characteristics
> + * @name: name of this PMIC variant
> + * @channels: the hardware channels and respective settings and defaults
> + * @broken_ratiometric: if the PMIC has broken ratiometric scaling (this
> + * is a known problem on PM8058)
> + * @prescaling: this variant uses AMUX bits 2 & 3 for prescaling (PM8058)
> + * @second_level_mux: this variant uses AMUX bits 2 & 3 for a second level
> + * mux
> + */
> +struct xoadc_variant {
> + const char name[16];
> + const struct xoadc_channel *channels;
> + bool broken_ratiometric;
> + bool prescaling;
> + bool second_level_mux;
> +};
> +
> +/*
> + * XOADC_CHAN macro parameters:
> + * _dname: the name of the channel
> + * _presmux: prescaler (PM8058) or premux (PM8921) setting for this channel
> + * _amux: the value in bits 2..7 of the ADC_ARB_USRP_AMUX_CNTRL register
> + * for this channel. On some PMICs some of the bits select a prescaler, and
> + * on some PMICs some of the bits select various complex multiplex settings.
> + * _type: IIO channel type
> + * _prenum: prescaler numerator (dividend)
> + * _preden: prescaler denominator (divisor)
> + * _scale: scaling function type, this selects how the raw valued is mangled
> + * to output the actual processed measurement
> + * _amip: analog mux input parent when using ratiometric measurements
> + */
> +#define XOADC_CHAN(_dname, _presmux, _amux, _type, _prenum, _preden, _scale, _amip) \
> + { \
> + .datasheet_name = __stringify(_dname), \
> + .pre_scale_mux = _presmux, \
> + .amux_channel = _amux, \
> + .prescale = { .num = _prenum, .den = _preden }, \
> + .type = _type, \
> + .scale_fn_type = _scale, \
> + .amux_ip_rsv = _amip, \
> + }
> +
> +/*
> + * Taken from arch/arm/mach-msm/board-9615.c in the vendor tree:
> + * TODO: incomplete, needs testing.
> + */
> +static const struct xoadc_channel pm8018_xoadc_channels[] = {
> + XOADC_CHAN(VCOIN, 0x00, 0x00, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(VBAT, 0x00, 0x01, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(VPH_PWR, 0x00, 0x02, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(DIE_TEMP, 0x00, 0x0b, IIO_TEMP, 1, 1, SCALE_PMIC_THERM, AMUX_RSV1),
> + /* Used for battery ID or battery temperature */
> + XOADC_CHAN(AMUX8, 0x00, 0x08, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV2),
> + XOADC_CHAN(INTERNAL, 0x00, 0x0c, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(125V, 0x00, 0x0d, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(MUXOFF, 0x00, 0x0f, IIO_TEMP, 1, 1, SCALE_XOTHERM, AMUX_RSV0),
> + { }, /* Sentinel */
> +};
> +
> +/*
> + * Taken from arch/arm/mach-msm/board-8930-pmic.c in the vendor tree:
> + * TODO: needs testing.
> + */
> +static const struct xoadc_channel pm8038_xoadc_channels[] = {
> + XOADC_CHAN(VCOIN, 0x00, 0x00, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(VBAT, 0x00, 0x01, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(DCIN, 0x00, 0x02, IIO_VOLTAGE, 1, 6, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(ICHG, 0x00, 0x03, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(VPH_PWR, 0x00, 0x04, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(AMUX5, 0x00, 0x05, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(AMUX6, 0x00, 0x06, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(AMUX7, 0x00, 0x07, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + /* AMUX8 used for battery temperature in most cases */
> + XOADC_CHAN(AMUX8, 0x00, 0x08, IIO_TEMP, 1, 1, SCALE_THERM_100K_PULLUP, AMUX_RSV2),
> + XOADC_CHAN(AMUX9, 0x00, 0x09, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(USB_VBUS, 0x00, 0x0a, IIO_VOLTAGE, 1, 4, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(DIE_TEMP, 0x00, 0x0b, IIO_TEMP, 1, 1, SCALE_PMIC_THERM, AMUX_RSV1),
> + XOADC_CHAN(INTERNAL, 0x00, 0x0c, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(125V, 0x00, 0x0d, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(INTERNAL_2, 0x00, 0x0e, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(MUXOFF, 0x00, 0x0f, IIO_TEMP, 1, 1, SCALE_XOTHERM, AMUX_RSV0),
> + { }, /* Sentinel */
> +};
> +
> +/*
> + * This was created by cross-referencing the vendor tree
> + * arch/arm/mach-msm/board-msm8x60.c msm_adc_channels_data[]
> + * with the "channel types" (first field) to find the right
> + * configuration for these channels on an MSM8x60 i.e. PM8058
> + * setup.
> + */
> +static const struct xoadc_channel pm8058_xoadc_channels[] = {
> + XOADC_CHAN(VCOIN, 0x00, 0x00, IIO_VOLTAGE, 1, 2, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(VBAT, 0x00, 0x01, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(DCIN, 0x00, 0x02, IIO_VOLTAGE, 1, 10, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(ICHG, 0x00, 0x03, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(VPH_PWR, 0x00, 0x04, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
> + /*
> + * AMUX channels 5 thru 9 are referred to as MPP5 thru MPP9 in
> + * some code and documentation. But they are really just 5
> + * channels just like any other. They are connected to a switching
> + * matrix where they can be routed to any of the MPPs, not just
> + * 1-to-1 onto MPP5 thru 9, so naming them MPP5 thru MPP9 is
> + * very confusing.
> + */
> + XOADC_CHAN(AMUX5, 0x00, 0x05, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(AMUX6, 0x00, 0x06, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(AMUX7, 0x00, 0x07, IIO_VOLTAGE, 1, 2, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(AMUX8, 0x00, 0x08, IIO_VOLTAGE, 1, 2, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(AMUX9, 0x00, 0x09, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(USB_VBUS, 0x00, 0x0a, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(DIE_TEMP, 0x00, 0x0b, IIO_TEMP, 1, 1, SCALE_PMIC_THERM, AMUX_RSV1),
> + XOADC_CHAN(INTERNAL, 0x00, 0x0c, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(125V, 0x00, 0x0d, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(INTERNAL_2, 0x00, 0x0e, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(MUXOFF, 0x00, 0x0f, IIO_TEMP, 1, 1, SCALE_XOTHERM, AMUX_RSV0),
> + /* There are also "unity" and divided by 3 channels (prescaler) but noone is using them */
> + { }, /* Sentinel */
> +};
> +
> +/*
> + * The PM8921 has some pre-muxing on its channels, this comes from the vendor tree
> + * include/linux/mfd/pm8xxx/pm8xxx-adc.h
> + * board-flo-pmic.c (Nexus 7) and board-8064-pmic.c
> + */
> +static const struct xoadc_channel pm8921_xoadc_channels[] = {
> + XOADC_CHAN(VCOIN, 0x00, 0x00, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(VBAT, 0x00, 0x01, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(DCIN, 0x00, 0x02, IIO_VOLTAGE, 1, 6, SCALE_DEFAULT, AMUX_RSV1),
> + /* channel "ICHG" is reserved and not used on PM8921 */
> + XOADC_CHAN(VPH_PWR, 0x00, 0x04, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(IBAT, 0x00, 0x05, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + /* CHAN 6 & 7 (MPP1 & MPP2) are reserved for MPP channels on PM8921 */
> + XOADC_CHAN(BATT_THERM, 0x00, 0x08, IIO_TEMP, 1, 1, SCALE_THERM_100K_PULLUP, AMUX_RSV1),
> + XOADC_CHAN(BATT_ID, 0x00, 0x09, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(USB_VBUS, 0x00, 0x0a, IIO_VOLTAGE, 1, 4, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(DIE_TEMP, 0x00, 0x0b, IIO_TEMP, 1, 1, SCALE_PMIC_THERM, AMUX_RSV1),
> + XOADC_CHAN(INTERNAL, 0x00, 0x0c, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(125V, 0x00, 0x0d, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + /* FIXME: look into the scaling of this temperature */
> + XOADC_CHAN(CHG_TEMP, 0x00, 0x0e, IIO_TEMP, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(MUXOFF, 0x00, 0x0f, IIO_TEMP, 1, 1, SCALE_XOTHERM, AMUX_RSV0),
> + /* The following channels have premux bit 0 set to 1 (all end in 4) */
> + XOADC_CHAN(ATEST_8, 0x01, 0x00, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + /* Set scaling to 1/2 based on the name for these two */
> + XOADC_CHAN(USB_SNS_DIV20, 0x01, 0x01, IIO_VOLTAGE, 1, 2, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(DCIN_SNS_DIV20, 0x01, 0x02, IIO_VOLTAGE, 1, 2, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(AMUX3, 0x01, 0x03, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(AMUX4, 0x01, 0x04, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(AMUX5, 0x01, 0x05, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(AMUX6, 0x01, 0x06, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(AMUX7, 0x01, 0x07, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(AMUX8, 0x01, 0x08, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + /* Internal test signals, I think */
> + XOADC_CHAN(ATEST_1, 0x01, 0x09, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(ATEST_2, 0x01, 0x0a, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(ATEST_3, 0x01, 0x0b, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(ATEST_4, 0x01, 0x0c, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(ATEST_5, 0x01, 0x0d, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(ATEST_6, 0x01, 0x0e, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(ATEST_7, 0x01, 0x0f, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
> + /* The following channels have premux bit 1 set to 1 (all end in 8) */
> + /* I guess even ATEST8 will be divided by 3 here */
> + XOADC_CHAN(ATEST_8, 0x02, 0x00, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
> + /* I guess div 2 div 3 becomes div 6 */
> + XOADC_CHAN(USB_SNS_DIV20_DIV3, 0x02, 0x01, IIO_VOLTAGE, 1, 6, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(DCIN_SNS_DIV20_DIV3, 0x02, 0x02, IIO_VOLTAGE, 1, 6, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(AMUX3_DIV3, 0x02, 0x03, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(AMUX4_DIV3, 0x02, 0x04, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(AMUX5_DIV3, 0x02, 0x05, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(AMUX6_DIV3, 0x02, 0x06, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(AMUX7_DIV3, 0x02, 0x07, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(AMUX8_DIV3, 0x02, 0x08, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(ATEST_1_DIV3, 0x02, 0x09, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(ATEST_2_DIV3, 0x02, 0x0a, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(ATEST_3_DIV3, 0x02, 0x0b, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(ATEST_4_DIV3, 0x02, 0x0c, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(ATEST_5_DIV3, 0x02, 0x0d, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(ATEST_6_DIV3, 0x02, 0x0e, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
> + XOADC_CHAN(ATEST_7_DIV3, 0x02, 0x0f, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
> + { }, /* Sentinel */
> +};
> +
> +/**
> + * struct pm8xxx_chan_info - ADC channel information
> + * @name: name of this channel
> + * @hwchan: pointer to hardware channel information (muxing & scaling settings)
> + * @calibration: whether to use absolute or ratiometric calibration
> + * @scale_fn_type: scaling function type
> + * @decimation: 0,1,2,3
> + * @amux_ip_rsv: ratiometric scale value if using ratiometric
> + * calibration: 0, 1, 2, 4, 5.
Consistent formatting ideally on those lists of options.
> + */
> +struct pm8xxx_chan_info {
> + const char *name;
> + const struct xoadc_channel *hwchan;
> + enum vadc_calibration calibration;
> + u8 decimation:2;
> + u8 amux_ip_rsv:3;
> +};
> +
> +/**
> + * struct pm8xxx_xoadc - state container for the XOADC
> + * @dev: pointer to device
> + * @map: regmap to access registers
> + * @vref: reference voltage regulator
> + * characteristics of the channels, and sensible default settings
> + * @nchans: number of channels, configured by the device tree
> + * @chans: the channel information per-channel, configured by the device tree
> + * @iio_chans: IIO channel specifiers
> + * @graph: linear calibration parameters for absolute and
> + * ratiometric measurements
> + * @complete: completion to indicate end of conversion
> + * @lock: lock to restrict access to the hardware to one client at the time
> + */
> +struct pm8xxx_xoadc {
> + struct device *dev;
> + struct regmap *map;
> + const struct xoadc_variant *variant;
> + struct regulator *vref;
> + unsigned int nchans;
> + struct pm8xxx_chan_info *chans;
> + struct iio_chan_spec *iio_chans;
> + struct vadc_linear_graph graph[2];
> + struct completion complete;
> + struct mutex lock;
> +};
> +
> +static irqreturn_t pm8xxx_eoc_irq(int irq, void *d)
> +{
> + struct iio_dev *indio_dev = d;
> + struct pm8xxx_xoadc *adc = iio_priv(indio_dev);
> +
> + complete(&adc->complete);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static struct pm8xxx_chan_info *
> +pm8xxx_get_channel(struct pm8xxx_xoadc *adc, u8 chan)
> +{
> + struct pm8xxx_chan_info *ch;
> + int i;
> +
> + for (i = 0; i < adc->nchans; i++) {
> + ch = &adc->chans[i];
> + if (ch->hwchan->amux_channel == chan)
> + break;
> + }
> + if (i == adc->nchans)
> + return NULL;
> +
> + return ch;
> +}
> +
> +static int pm8xxx_read_channel_rsv(struct pm8xxx_xoadc *adc,
> + const struct pm8xxx_chan_info *ch,
> + u8 rsv, u16 *adc_code,
> + bool force_ratiometric)
> +{
> + int ret;
> + unsigned int val;
> + u8 rsvmask, rsvval;
> + u8 lsb, msb;
> +
> + dev_dbg(adc->dev, "read channel \"%s\", amux %d, prescale/mux: %d, rsv %d\n",
> + ch->name, ch->hwchan->amux_channel, ch->hwchan->pre_scale_mux, rsv);
> +
> + mutex_lock(&adc->lock);
> +
> + /* Mux in this channel */
> + val = ch->hwchan->amux_channel << ADC_AMUX_SEL_SHIFT;
> + val |= ch->hwchan->pre_scale_mux << ADC_AMUX_PREMUX_SHIFT;
> + ret = regmap_write(adc->map, ADC_ARB_USRP_AMUX_CNTRL, val);
> + if (ret)
> + goto unlock;
> +
> + /* Set up ratiometric scale value, mask off all bits except these */
> + rsvmask = (ADC_ARB_USRP_RSV_RST | ADC_ARB_USRP_RSV_DTEST0 |
> + ADC_ARB_USRP_RSV_DTEST1 | ADC_ARB_USRP_RSV_OP);
> + if (adc->variant->broken_ratiometric && !force_ratiometric) {
> + /*
> + * Apparently the PM8058 has some kind of bug which is
> + * reflected in the vendor tree drivers/misc/pmix8058-xoadc.c
> + * which just hardcodes the RSV selector to SEL1 (0x20) for
> + * most cases and SEL0 (0x10) for the MUXOFF channel only.
> + * If we force ratiometric (currently only done when attempting
> + * to do ratiometric calibration) this doesn't seem to work
> + * very well and I suspect ratiometric conversion is simply
> + * broken or not supported on the PM8058.
> + *
> + * Maybe IO_SEL2 doesn't exist on PM8058 and bits 4 & 5 select
> + * the mode alone.
> + *
> + * Some PM8058 register documentation would be nice to get
> + * this right.
> + */
> + if (ch->hwchan->amux_channel == PM8XXX_CHANNEL_MUXOFF)
> + rsvval = ADC_ARB_USRP_RSV_IP_SEL0;
> + else
> + rsvval = ADC_ARB_USRP_RSV_IP_SEL1;
> + } else {
> + if (rsv == 0xff)
> + rsvval = (ch->amux_ip_rsv << ADC_RSV_IP_SEL_SHIFT) |
> + ADC_ARB_USRP_RSV_TRM;
> + else
> + rsvval = (rsv << ADC_RSV_IP_SEL_SHIFT) |
> + ADC_ARB_USRP_RSV_TRM;
> + }
> +
> + ret = regmap_update_bits(adc->map,
> + ADC_ARB_USRP_RSV,
> + ~rsvmask,
> + rsvval);
> + if (ret)
> + goto unlock;
> +
> + ret = regmap_write(adc->map, ADC_ARB_USRP_ANA_PARAM,
> + ADC_ARB_USRP_ANA_PARAM_DIS);
> + if (ret)
> + goto unlock;
> +
> + /* Decimation factor */
> + ret = regmap_write(adc->map, ADC_ARB_USRP_DIG_PARAM,
> + ADC_ARB_USRP_DIG_PARAM_SEL_SHIFT0 |
> + ADC_ARB_USRP_DIG_PARAM_SEL_SHIFT1 |
> + ch->decimation << ADC_DIG_PARAM_DEC_SHIFT);
> + if (ret)
> + goto unlock;
> +
> + ret = regmap_write(adc->map, ADC_ARB_USRP_ANA_PARAM,
> + ADC_ARB_USRP_ANA_PARAM_EN);
> + if (ret)
> + goto unlock;
> +
> + /* Enable the arbiter, the Qualcomm code does it twice like this */
> + ret = regmap_write(adc->map, ADC_ARB_USRP_CNTRL,
> + ADC_ARB_USRP_CNTRL_EN_ARB);
> + if (ret)
> + goto unlock;
> + ret = regmap_write(adc->map, ADC_ARB_USRP_CNTRL,
> + ADC_ARB_USRP_CNTRL_EN_ARB);
> + if (ret)
> + goto unlock;
Yuk. I guess you tried it without? Who knows if it is a hardware work around
or a cut and paste error in the driver...
> +
> +
> + /* Fire a request! */
> + reinit_completion(&adc->complete);
> + ret = regmap_write(adc->map, ADC_ARB_USRP_CNTRL,
> + ADC_ARB_USRP_CNTRL_EN_ARB |
> + ADC_ARB_USRP_CNTRL_REQ);
> + if (ret)
> + goto unlock;
> +
> + /* Next the interrupt occurs */
> + ret = wait_for_completion_timeout(&adc->complete,
> + VADC_CONV_TIME_MAX_US);
> + if (!ret) {
> + dev_err(adc->dev, "conversion timed out\n");
> + ret = -ETIMEDOUT;
> + goto unlock;
> + }
> +
> + ret = regmap_read(adc->map, ADC_ARB_USRP_DATA0, &val);
> + if (ret)
> + goto unlock;
> + lsb = val;
> + ret = regmap_read(adc->map, ADC_ARB_USRP_DATA1, &val);
> + if (ret)
> + goto unlock;
> + msb = val;
> + *adc_code = (msb << 8) | lsb;
> +
> + /* Turn off the ADC by setting the arbiter to 0 twice */
> + ret = regmap_write(adc->map, ADC_ARB_USRP_CNTRL, 0);
> + if (ret)
> + goto unlock;
> + ret = regmap_write(adc->map, ADC_ARB_USRP_CNTRL, 0);
> + if (ret)
> + goto unlock;
> +
> +unlock:
> + mutex_unlock(&adc->lock);
> + return ret;
> +}
> +
> +static int pm8xxx_read_channel(struct pm8xxx_xoadc *adc,
> + const struct pm8xxx_chan_info *ch,
> + u16 *adc_code)
> +{
> + /*
> + * Normally we just use the ratiometric scale value (RSV) predefined
> + * for the channel, but during calibration we need to modify this
> + * so this wrapper is a helper hiding the more complex version.
> + */
> + return pm8xxx_read_channel_rsv(adc, ch, 0xff, adc_code, false);
> +}
> +
> +static int pm8xxx_calibrate_device(struct pm8xxx_xoadc *adc)
> +{
> + const struct pm8xxx_chan_info *ch;
> + u16 read_1250v;
> + u16 read_0625v;
> + u16 read_nomux_rsv5;
> + u16 read_nomux_rsv4;
> + int ret;
> +
> + adc->graph[VADC_CALIB_ABSOLUTE].dx = VADC_ABSOLUTE_RANGE_UV;
> + adc->graph[VADC_CALIB_RATIOMETRIC].dx = VADC_RATIOMETRIC_RANGE;
> +
> + /* Common reference channel calibration */
> + ch = pm8xxx_get_channel(adc, PM8XXX_CHANNEL_125V);
> + if (!ch)
> + return -ENODEV;
> + ret = pm8xxx_read_channel(adc, ch, &read_1250v);
> + if (ret) {
> + dev_err(adc->dev, "could not read 1.25V reference channel\n");
> + return -ENODEV;
> + }
> + ch = pm8xxx_get_channel(adc, PM8XXX_CHANNEL_INTERNAL);
> + if (!ch)
> + return -ENODEV;
> + ret = pm8xxx_read_channel(adc, ch, &read_0625v);
> + if (ret) {
> + dev_err(adc->dev, "could not read 0.625V reference channel\n");
> + return -ENODEV;
> + }
> + if (read_1250v == read_0625v) {
> + dev_err(adc->dev, "read same ADC code for 1.25V and 0.625V\n");
> + return -ENODEV;
> + }
> +
> + adc->graph[VADC_CALIB_ABSOLUTE].dy = read_1250v - read_0625v;
> + adc->graph[VADC_CALIB_ABSOLUTE].gnd = read_0625v;
> +
> + dev_info(adc->dev, "absolute calibration dx = %d uV, dy = %d units\n",
> + VADC_ABSOLUTE_RANGE_UV, adc->graph[VADC_CALIB_ABSOLUTE].dy);
> +
> + /* Ratiometric calibration */
> + ch = pm8xxx_get_channel(adc, PM8XXX_CHANNEL_MUXOFF);
> + if (!ch)
> + return -ENODEV;
> + ret = pm8xxx_read_channel_rsv(adc, ch, AMUX_RSV5,
> + &read_nomux_rsv5, true);
> + if (ret) {
> + dev_err(adc->dev, "could not read MUXOFF reference channel\n");
> + return -ENODEV;
> + }
> + ret = pm8xxx_read_channel_rsv(adc, ch, AMUX_RSV4,
> + &read_nomux_rsv4, true);
> + if (ret) {
> + dev_err(adc->dev, "could not read MUXOFF reference channel\n");
> + return -ENODEV;
> + }
> + adc->graph[VADC_CALIB_RATIOMETRIC].dy =
> + read_nomux_rsv5 - read_nomux_rsv4;
> + adc->graph[VADC_CALIB_RATIOMETRIC].gnd = read_nomux_rsv4;
> +
> + dev_info(adc->dev, "ratiometric calibration dx = %d, dy = %d units\n",
> + VADC_RATIOMETRIC_RANGE,
> + adc->graph[VADC_CALIB_RATIOMETRIC].dy);
> +
> + return 0;
> +}
> +
> +static int pm8xxx_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val, int *val2, long mask)
> +{
> + struct pm8xxx_xoadc *adc = iio_priv(indio_dev);
> + const struct pm8xxx_chan_info *ch;
> + u16 adc_code;
> + int ret;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_PROCESSED:
> + ch = pm8xxx_get_channel(adc, chan->address);
> + if (!ch) {
> + dev_err(adc->dev, "no such channel %lu\n",
> + chan->address);
> + return -EINVAL;
> + }
> + ret = pm8xxx_read_channel(adc, ch, &adc_code);
> + if (ret)
> + return ret;
> +
> + ret = qcom_vadc_scale(ch->hwchan->scale_fn_type,
> + &adc->graph[ch->calibration],
> + &ch->hwchan->prescale,
> + (ch->calibration == VADC_CALIB_ABSOLUTE),
> + adc_code, val);
> + if (ret)
> + return ret;
> +
> + return IIO_VAL_INT;
> + case IIO_CHAN_INFO_RAW:
> + ch = pm8xxx_get_channel(adc, chan->address);
> + if (!ch) {
> + dev_err(adc->dev, "no such channel %lu\n",
> + chan->address);
> + return -EINVAL;
> + }
> + ret = pm8xxx_read_channel(adc, ch, &adc_code);
> + if (ret)
> + return ret;
> +
> + *val = (int)adc_code;
> + return IIO_VAL_INT;
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static int pm8xxx_of_xlate(struct iio_dev *indio_dev,
> + const struct of_phandle_args *iiospec)
> +{
> + struct pm8xxx_xoadc *adc = iio_priv(indio_dev);
> + u8 pre_scale_mux;
> + u8 amux_channel;
> + unsigned int i;
> +
> + /*
> + * First cell is prescaler or premux, second cell is analog
> + * mux.
> + */
> + if (iiospec->args_count != 2) {
> + dev_err(&indio_dev->dev, "wrong number of arguments for %s need 2 got %d\n",
> + iiospec->np->name,
> + iiospec->args_count);
> + return -EINVAL;
> + }
> + pre_scale_mux = (u8)iiospec->args[0];
> + amux_channel = (u8)iiospec->args[1];
> + dev_dbg(&indio_dev->dev, "pre scale/mux: %02x, amux: %02x\n",
> + pre_scale_mux, amux_channel);
> +
> + /* We need to match exactly on the prescale/premux and channel */
> + for (i = 0; i < adc->nchans; i++)
> + if (adc->chans[i].hwchan->pre_scale_mux == pre_scale_mux &&
> + adc->chans[i].hwchan->amux_channel == amux_channel)
> + return i;
> +
> + return -EINVAL;
> +}
> +
> +static const struct iio_info pm8xxx_xoadc_info = {
> + .driver_module = THIS_MODULE,
> + .of_xlate = pm8xxx_of_xlate,
> + .read_raw = pm8xxx_read_raw,
> +};
> +
> +static int pm8xxx_xoadc_parse_channel(struct device *dev,
> + struct device_node *np,
> + const struct xoadc_channel *hw_channels,
> + struct iio_chan_spec *iio_chan,
> + struct pm8xxx_chan_info *ch)
> +{
> + const char *name = np->name;
> + const struct xoadc_channel *hwchan;
> + u32 pre_scale_mux, amux_channel;
> + u32 rsv, dec;
> + int ret;
> + int chid;
> +
> + ret = of_property_read_u32_index(np, "reg", 0, &pre_scale_mux);
> + if (ret) {
> + dev_err(dev, "invalid pre scale/mux number %s\n", name);
> + return ret;
> + }
> + ret = of_property_read_u32_index(np, "reg", 1, &amux_channel);
> + if (ret) {
> + dev_err(dev, "invalid amux channel number %s\n", name);
> + return ret;
> + }
> +
> + /* Find the right channel setting */
> + chid = 0;
> + hwchan = &hw_channels[0];
> + while (hwchan && hwchan->datasheet_name) {
> + if (hwchan->pre_scale_mux == pre_scale_mux &&
> + hwchan->amux_channel == amux_channel)
> + break;
> + hwchan++;
> + chid++;
> + }
> + /* The sentinel does not have a name assigned */
> + if (!hwchan->datasheet_name) {
> + dev_err(dev, "could not locate channel %02x/%02x\n",
> + pre_scale_mux, amux_channel);
> + return -EINVAL;
> + }
> + ch->name = name;
> + ch->hwchan = hwchan;
> + /* Everyone seems to use absolute calibration except in special cases */
> + ch->calibration = VADC_CALIB_ABSOLUTE;
> + /* Everyone seems to use default ("type 2") decimation */
> + ch->decimation = VADC_DEF_DECIMATION;
> +
> + if (!of_property_read_u32(np, "qcom,ratiometric", &rsv)) {
> + ch->calibration = VADC_CALIB_RATIOMETRIC;
> + if (rsv > XOADC_RSV_MAX) {
> + dev_err(dev, "%s too large RSV value %d\n", name, rsv);
> + return -EINVAL;
> + }
> + if (rsv == AMUX_RSV3) {
> + dev_err(dev, "%s invalid RSV value %d\n", name, rsv);
> + return -EINVAL;
> + }
> + }
> +
> + /* Optional decimation, if omitted we use the default */
> + ret = of_property_read_u32(np, "qcom,decimation", &dec);
> + if (!ret) {
> + ret = qcom_vadc_decimation_from_dt(dec);
> + if (ret < 0) {
> + dev_err(dev, "%s invalid decimation %d\n",
> + name, dec);
> + return ret;
> + }
> + ch->decimation = ret;
> + }
> +
> + iio_chan->channel = chid;
> + iio_chan->address = hwchan->amux_channel;
> + iio_chan->datasheet_name = hwchan->datasheet_name;
> + iio_chan->type = hwchan->type;
> + /* All channels are raw or processed */
> + iio_chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_PROCESSED);
> + iio_chan->indexed = 1;
> +
> + dev_dbg(dev, "channel [PRESCALE/MUX: %02x AMUX: %02x] \"%s\" "
> + "ref voltage: %d, decimation %d "
> + "prescale %d/%d, scale function %d\n",
> + hwchan->pre_scale_mux, hwchan->amux_channel, ch->name,
> + ch->amux_ip_rsv, ch->decimation, hwchan->prescale.num,
> + hwchan->prescale.den, hwchan->scale_fn_type);
> +
> + return 0;
> +}
> +
> +static int pm8xxx_xoadc_parse_channels(struct pm8xxx_xoadc *adc,
> + struct device_node *np)
> +{
> + struct device_node *child;
> + struct pm8xxx_chan_info *ch;
> + int ret;
> + int i;
> +
> + adc->nchans = of_get_available_child_count(np);
> + if (!adc->nchans) {
> + dev_err(adc->dev, "no channel children\n");
> + return -ENODEV;
> + }
> + dev_dbg(adc->dev, "found %d ADC channels\n", adc->nchans);
> +
> + adc->iio_chans = devm_kcalloc(adc->dev, adc->nchans,
> + sizeof(*adc->iio_chans), GFP_KERNEL);
> + if (!adc->iio_chans)
> + return -ENOMEM;
> +
> + adc->chans = devm_kcalloc(adc->dev, adc->nchans,
> + sizeof(*adc->chans), GFP_KERNEL);
> + if (!adc->chans)
> + return -ENOMEM;
> +
> + i = 0;
> + for_each_available_child_of_node(np, child) {
> + ch = &adc->chans[i];
> + ret = pm8xxx_xoadc_parse_channel(adc->dev, child,
> + adc->variant->channels,
> + &adc->iio_chans[i],
> + ch);
> + if (ret) {
> + of_node_put(child);
> + return ret;
> + }
> + i++;
> + }
> +
> + /* Check for required channels */
> + ch = pm8xxx_get_channel(adc, PM8XXX_CHANNEL_125V);
> + if (!ch) {
> + dev_err(adc->dev, "missing 1.25V reference channel\n");
> + return -ENODEV;
> + }
> + ch = pm8xxx_get_channel(adc, PM8XXX_CHANNEL_INTERNAL);
> + if (!ch) {
> + dev_err(adc->dev, "missing 0.625V reference channel\n");
> + return -ENODEV;
> + }
> + ch = pm8xxx_get_channel(adc, PM8XXX_CHANNEL_MUXOFF);
> + if (!ch) {
> + dev_err(adc->dev, "missing MUXOFF reference channel\n");
> + return -ENODEV;
> + }
> +
> + return 0;
> +}
> +
> +static int pm8xxx_xoadc_probe(struct platform_device *pdev)
> +{
> + const struct xoadc_variant *variant;
> + struct pm8xxx_xoadc *adc;
> + struct iio_dev *indio_dev;
> + struct device_node *np = pdev->dev.of_node;
> + struct regmap *map;
> + struct device *dev = &pdev->dev;
> + int ret;
> +
> + variant = of_device_get_match_data(dev);
> + if (!variant)
> + return -ENODEV;
> +
> + indio_dev = devm_iio_device_alloc(dev, sizeof(*adc));
> + if (!indio_dev)
> + return -ENOMEM;
> + platform_set_drvdata(pdev, indio_dev);
> +
> + adc = iio_priv(indio_dev);
> + adc->dev = dev;
> + adc->variant = variant;
> + init_completion(&adc->complete);
> + mutex_init(&adc->lock);
> +
> + ret = pm8xxx_xoadc_parse_channels(adc, np);
> + if (ret)
> + return ret;
> +
> + map = dev_get_regmap(dev->parent, NULL);
> + if (!map) {
> + dev_err(dev, "parent regmap unavailable.\n");
> + return -ENXIO;
> + }
> + adc->map = map;
> +
> + /* Bring up regulator */
Going for the obvious docs there ;)
> + adc->vref = devm_regulator_get(dev, "xoadc-ref");
> + if (IS_ERR(adc->vref)) {
> + dev_err(dev, "failed to get XOADC VREF regulator\n");
> + return PTR_ERR(adc->vref);
> + }
> + ret = regulator_enable(adc->vref);
> + if (ret) {
> + dev_err(dev, "failed to enable XOADC VREF regulator\n");
> + return ret;
> + }
> +
> + ret = devm_request_threaded_irq(dev, platform_get_irq(pdev, 0),
> + pm8xxx_eoc_irq, NULL, 0, variant->name, indio_dev);
I know that it'll map to the same thing anyway, but why claim it's a
threaded irq and not provide a thread? I'd just use devm_request_irq.
> + if (ret) {
> + dev_err(dev, "unable to request IRQ\n");
> + goto out_disable_vref;
> + }
> +
> + indio_dev->dev.parent = dev;
> + indio_dev->dev.of_node = np;
> + indio_dev->name = variant->name;
> + indio_dev->modes = INDIO_DIRECT_MODE;
> + indio_dev->info = &pm8xxx_xoadc_info;
> + indio_dev->channels = adc->iio_chans;
> + indio_dev->num_channels = adc->nchans;
> +
> + ret = iio_device_register(indio_dev);
> + if (ret)
> + goto out_disable_vref;
> +
> + ret = pm8xxx_calibrate_device(adc);
I'd not noticed this before, but looks like an unnecessary race to have
uncalibrated reads a possiblity by having this after the exposure to
userspace and consumers that iio_device_register implies.
Can we not just move this up a few lines?
> + if (ret)
> + goto out_unreg_device;
> +
> + dev_info(dev, "%s XOADC driver enabled\n", variant->name);
> +
> + return 0;
> +
> +out_unreg_device:
> + iio_device_unregister(indio_dev);
> +out_disable_vref:
> + regulator_disable(adc->vref);
> +
> + return ret;
> +}
> +
> +static int pm8xxx_xoadc_remove(struct platform_device *pdev)
> +{
> + struct iio_dev *indio_dev = platform_get_drvdata(pdev);
> + struct pm8xxx_xoadc *adc = iio_priv(indio_dev);
> +
> + iio_device_unregister(indio_dev);
> +
> + regulator_disable(adc->vref);
One day we will talk mark into a devm_regulator_enable for all these
devices where dynamic power management is just far too tricky!
> +
> + return 0;
> +}
> +
> +static const struct xoadc_variant pm8018_variant = {
> + .name = "PM8018-XOADC",
> + .channels = pm8018_xoadc_channels,
> +};
> +
> +static const struct xoadc_variant pm8038_variant = {
> + .name = "PM8038-XOADC",
> + .channels = pm8038_xoadc_channels,
> +};
> +
> +static const struct xoadc_variant pm8058_variant = {
> + .name = "PM8058-XOADC",
> + .channels = pm8058_xoadc_channels,
> + .broken_ratiometric = true,
> + .prescaling = true,
> +};
> +
> +static const struct xoadc_variant pm8921_variant = {
> + .name = "PM8921-XOADC",
> + .channels = pm8921_xoadc_channels,
> + .second_level_mux = true,
> +};
> +
> +static const struct of_device_id pm8xxx_xoadc_id_table[] = {
> + {
> + .compatible = "qcom,pm8018-adc",
> + .data = &pm8018_variant,
> + },
> + {
> + .compatible = "qcom,pm8038-adc",
> + .data = &pm8038_variant,
> + },
> + {
> + .compatible = "qcom,pm8058-adc",
> + .data = &pm8058_variant,
> + },
> + {
> + .compatible = "qcom,pm8921-adc",
> + .data = &pm8921_variant,
> + },
> + { },
> +};
> +MODULE_DEVICE_TABLE(of, pm8xxx_xoadc_id_table);
> +
> +static struct platform_driver pm8xxx_xoadc_driver = {
> + .driver = {
> + .name = "pm8xxx-adc",
> + .of_match_table = pm8xxx_xoadc_id_table,
> + },
> + .probe = pm8xxx_xoadc_probe,
> + .remove = pm8xxx_xoadc_remove,
> +};
> +module_platform_driver(pm8xxx_xoadc_driver);
> +
> +MODULE_DESCRIPTION("PM8xxx XOADC driver");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:pm8xxx-xoadc");
>
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