RE: [PATCH 2/3] iio: adc: Add Xilinx AMS driver

From: Manish Narani
Date: Thu Sep 06 2018 - 11:20:52 EST

Hi Jonathan,

Thanks a lot for the review. Please see my response inline.

> -----Original Message-----
> From: Jonathan Cameron [mailto:jic23@xxxxxxxxxx]
> Sent: Monday, September 3, 2018 1:27 AM
> To: Manish Narani <MNARANI@xxxxxxxxxx>
> Cc: knaack.h@xxxxxx; lars@xxxxxxxxxx; pmeerw@xxxxxxxxxx;
> robh+dt@xxxxxxxxxx; mark.rutland@xxxxxxx; Michal Simek
> <michals@xxxxxxxxxx>; leoyang.li@xxxxxxx; sudeep.holla@xxxxxxx;
> amit.kucheria@xxxxxxxxxx; broonie@xxxxxxxxxx; arnaud.pouliquen@xxxxxx;
> geert@xxxxxxxxxxxxxx; eugen.hristev@xxxxxxxxxxxxx; rdunlap@xxxxxxxxxxxxx;
> lukas@xxxxxxxxx; freeman.liu@xxxxxxxxxxxxxx; vilhelm.gray@xxxxxxxxx;
> tglx@xxxxxxxxxxxxx; baolin.wang@xxxxxxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx;
> Srinivas Goud <sgoud@xxxxxxxxxx>; Anirudha Sarangi <anirudh@xxxxxxxxxx>;
> linux-iio@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux-arm-
> kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH 2/3] iio: adc: Add Xilinx AMS driver
>
> On Thu, 30 Aug 2018 15:52:18 +0530
> Manish Narani <manish.narani@xxxxxxxxxx> wrote:
>
> > The AMS includes an ADC as well as on-chip sensors that can be used to
> > sample external voltages and monitor on-die operating conditions, such
> > as temperature and supply voltage levels. The AMS has two SYSMON blocks.
> > PL-SYSMON block is capable of monitoring off chip voltage and
> > temperature.
> > PL-SYSMON block has DRP, JTAG and I2C interface to enable monitoring
> > from external master. Out of these interface currently only DRP is
> > supported.
> > Other block PS-SYSMON is memory mapped to PS.
> > The AMS can use internal channels to monitor voltage and temperature
> > as well as one primary and up to 16 auxiliary channels for measuring
> > external voltages.
> > The voltage and temperature monitoring channels also have event
> > capability which allows to generate an interrupt when their value
> > falls below or raises above a set threshold.
> >
> > Signed-off-by: Manish Narani <manish.narani@xxxxxxxxxx>
>
> Given the use of extended_name in here, there is a whole lot of undocumented
> userspace ABI. Please add to
>
> Documentation/ABI/testing/sysfs-bus-iio-xilinx-ams or similar.

Okay sure.

>
> I am a little concerned at introducing quite so many of these.
> Perhaps we need to revisit how we represent this sort of information...
>
> Otherwise, a few minor things inline but looking fairly good overall.
>
> Thanks,
>
> Jonathan
>
> > ---
> > drivers/iio/adc/Kconfig | 10 +
> > drivers/iio/adc/Makefile | 1 +
> > drivers/iio/adc/xilinx-ams.c | 1081
> > ++++++++++++++++++++++++++++++++++++++++++
> > drivers/iio/adc/xilinx-ams.h | 281 +++++++++++
> > 4 files changed, 1373 insertions(+)
> > create mode 100644 drivers/iio/adc/xilinx-ams.c create mode 100644
> > drivers/iio/adc/xilinx-ams.h
> >
> > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index
> > 4a75492..405ea00 100644
> > --- a/drivers/iio/adc/Kconfig
> > +++ b/drivers/iio/adc/Kconfig
> > @@ -941,4 +941,14 @@ config XILINX_XADC
> > The driver can also be build as a module. If so, the module will be
> called
> > xilinx-xadc.
> >
> > +config XILINX_AMS
> > + tristate "Xilinx AMS driver"
> > + depends on ARCH_ZYNQMP || COMPILE_TEST
> > + depends on HAS_IOMEM
> > + help
> > + Say yes here to have support for the Xilinx AMS.
> > +
> > + The driver can also be build as a module. If so, the module will be
> called
> > + xilinx-ams.
> > +
> > endmenu
> > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index
> > 03db7b5..fbfcc45 100644
> > --- a/drivers/iio/adc/Makefile
> > +++ b/drivers/iio/adc/Makefile
> > @@ -85,4 +85,5 @@ obj-$(CONFIG_VF610_ADC) += vf610_adc.o
> > obj-$(CONFIG_VIPERBOARD_ADC) += viperboard_adc.o xilinx-xadc-y :=
> > xilinx-xadc-core.o xilinx-xadc-events.o
> > obj-$(CONFIG_XILINX_XADC) += xilinx-xadc.o
> > +obj-$(CONFIG_XILINX_AMS) += xilinx-ams.o
> > obj-$(CONFIG_SD_ADC_MODULATOR) += sd_adc_modulator.o diff --git
> > a/drivers/iio/adc/xilinx-ams.c b/drivers/iio/adc/xilinx-ams.c new file
> > mode 100644 index 0000000..10bcc52
> > --- /dev/null
> > +++ b/drivers/iio/adc/xilinx-ams.c
> > @@ -0,0 +1,1081 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Xilinx AMS driver
> > + *
> > + * Copyright (C) 2017-2018 Xilinx, Inc.
> > + *
> > + * Manish Narani <mnarani@xxxxxxxxxx>
> > + * Rajnikant Bhojani <rajnikant.bhojani@xxxxxxxxxx> */
> > +
> > +#include <linux/kernel.h>
> > +#include <linux/slab.h>
> > +#include <linux/module.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/clk.h>
> > +#include <linux/of_address.h>
> > +#include <linux/iopoll.h>
> > +#include <linux/delay.h>
> There is a rough convention of alphabetical order if there isn't a reason to do
> otherwise.
>
> Here you might keep the iio headers for their own block at the end, but the rest
> should be in order.

Okay I will try to follow the same and update in v2.

>
> > +#include <linux/iio/iio.h>
> > +#include <linux/iio/sysfs.h>
> > +#include <linux/iio/events.h>
> > +#include <linux/io.h>
> > +
> > +#include "xilinx-ams.h"
> > +
> > +static const unsigned int AMS_UNMASK_TIMEOUT_MS = 500;
> > +
> > +static inline void ams_ps_update_reg(struct ams *ams, unsigned int offset,
> > + u32 mask, u32 data)
> > +{
> > + u32 val;
> > +
> > + val = readl(ams->ps_base + offset);
> > + writel((val & ~mask) | (data & mask), ams->ps_base + offset); }
> > +
> > +static inline void ams_pl_write_reg(struct ams *ams, unsigned int offset,
> > + u32 data)
> > +{
> > + writel(data, ams->pl_base + offset); }
> I'm always anti wrappers that don't add much. In this driver you also only use
> them 'sometimes'.

Okay, I will use writel inline in v2

>
> I'd prefer just having the writel inline all the time. The update functions have a
> little more purpose and given they are called quite often, perhaps are worth
> keeping.
>
> Another option is to use regmap for the whole thing getting you update
> functions and caching etc. Might not be worth it here. Up to you.

Sure. I will try to explore this.

>
> > +
> > +static inline void ams_pl_update_reg(struct ams *ams, unsigned int offset,
> > + u32 mask, u32 data)
> > +{
> > + u32 val;
> > +
> > + val = readl(ams->pl_base + offset);
> > + writel((val & ~mask) | (data & mask), ams->pl_base + offset); }
> > +
> > +static void ams_update_intrmask(struct ams *ams, u64 mask, u64 val) {
> > + ams->intr_mask &= ~mask;
> > + ams->intr_mask |= (val & mask);
> > +
> > + writel(~(ams->intr_mask | ams->masked_alarm), ams->base +
> AMS_IER_0);
> > + writel(~(ams->intr_mask >> AMS_ISR1_INTR_MASK_SHIFT),
> > + ams->base + AMS_IER_1);
> > + writel(ams->intr_mask | ams->masked_alarm, ams->base +
> AMS_IDR_0);
> > + writel(ams->intr_mask >> AMS_ISR1_INTR_MASK_SHIFT,
> > + ams->base + AMS_IDR_1);
> > +}
> > +
> > +static void ams_disable_all_alarms(struct ams *ams) {
> > + /* disable PS module alarm */
> > + if (ams->ps_base) {
> > + ams_ps_update_reg(ams, AMS_REG_CONFIG1,
> AMS_REGCFG1_ALARM_MASK,
> > + AMS_REGCFG1_ALARM_MASK);
> > + ams_ps_update_reg(ams, AMS_REG_CONFIG3,
> AMS_REGCFG3_ALARM_MASK,
> > + AMS_REGCFG3_ALARM_MASK);
> > + }
> > +
> > + /* disable PL module alarm */
> > + if (ams->pl_base) {
> > + ams_pl_update_reg(ams, AMS_REG_CONFIG1,
> > + AMS_REGCFG1_ALARM_MASK,
> > + AMS_REGCFG1_ALARM_MASK);
> > + ams_pl_update_reg(ams, AMS_REG_CONFIG3,
> > + AMS_REGCFG3_ALARM_MASK,
> > + AMS_REGCFG3_ALARM_MASK);
> > + }
> > +}
> > +
> > +static void iio_ams_update_alarm(struct ams *ams, unsigned long
> > +alarm_mask) {
> > + u32 cfg;
> > + unsigned long flags;
> > + unsigned long pl_alarm_mask;
> > +
> > + if (ams->ps_base) {
> > + /* Configuring PS alarm enable */
> > + cfg = ~((alarm_mask & AMS_ISR0_ALARM_2_TO_0_MASK) <<
> > + AMS_CONF1_ALARM_2_TO_0_SHIFT);
> > + cfg &= ~((alarm_mask & AMS_ISR0_ALARM_6_TO_3_MASK)
> <<
> > + AMS_CONF1_ALARM_6_TO_3_SHIFT);
> > + ams_ps_update_reg(ams, AMS_REG_CONFIG1,
> AMS_REGCFG1_ALARM_MASK,
> > + cfg);
> > +
> > + cfg = ~((alarm_mask >>
> AMS_CONF3_ALARM_12_TO_7_SHIFT) &
> > + AMS_ISR0_ALARM_12_TO_7_MASK);
> > + ams_ps_update_reg(ams, AMS_REG_CONFIG3,
> AMS_REGCFG3_ALARM_MASK,
> > + cfg);
> > + }
> > +
> > + if (ams->pl_base) {
> > + pl_alarm_mask = (alarm_mask >> AMS_PL_ALARM_START);
> > + /* Configuring PL alarm enable */
> > + cfg = ~((pl_alarm_mask & AMS_ISR0_ALARM_2_TO_0_MASK)
> <<
> > + AMS_CONF1_ALARM_2_TO_0_SHIFT);
> > + cfg &= ~((pl_alarm_mask &
> AMS_ISR0_ALARM_6_TO_3_MASK) <<
> > + AMS_CONF1_ALARM_6_TO_3_SHIFT);
> > + ams_pl_update_reg(ams, AMS_REG_CONFIG1,
> > + AMS_REGCFG1_ALARM_MASK, cfg);
> > +
> > + cfg = ~((pl_alarm_mask >>
> AMS_CONF3_ALARM_12_TO_7_SHIFT) &
> > + AMS_ISR0_ALARM_12_TO_7_MASK);
> > + ams_pl_update_reg(ams, AMS_REG_CONFIG3,
> > + AMS_REGCFG3_ALARM_MASK, cfg);
> > + }
> > +
> > + spin_lock_irqsave(&ams->lock, flags);
> > + ams_update_intrmask(ams, AMS_ISR0_ALARM_MASK, ~alarm_mask);
> > + spin_unlock_irqrestore(&ams->lock, flags); }
> > +
> > +static void ams_enable_channel_sequence(struct ams *ams) {
> > + int i;
> > + unsigned long long scan_mask;
> > + struct iio_dev *indio_dev = iio_priv_to_dev(ams);
> > +
> > + /*
> > + * Enable channel sequence. First 22 bit of scan_mask represent
> > + * PS channels, and next remaining bit represents PL channels.
> > + */
> > +
> > + /* Run calibration of PS & PL as part of the sequence */
> > + scan_mask = 0x1 | BIT(PS_SEQ_MAX);
> > + for (i = 0; i < indio_dev->num_channels; i++)
> > + scan_mask |= BIT(indio_dev->channels[i].scan_index);
> > +
> > + if (ams->ps_base) {
> > + /* put sysmon in a soft reset to change the sequence */
> > + ams_ps_update_reg(ams, AMS_REG_CONFIG1,
> AMS_CONF1_SEQ_MASK,
> > + AMS_CONF1_SEQ_DEFAULT);
> > +
> > + /* configure basic channels */
> > + writel(scan_mask & AMS_REG_SEQ0_MASK,
> > + ams->ps_base + AMS_REG_SEQ_CH0);
> > + writel(AMS_REG_SEQ2_MASK &
> > + (scan_mask >> AMS_REG_SEQ2_MASK_SHIFT),
> > + ams->ps_base + AMS_REG_SEQ_CH2);
> > +
> > + /* set continuous sequence mode */
> > + ams_ps_update_reg(ams, AMS_REG_CONFIG1,
> AMS_CONF1_SEQ_MASK,
> > + AMS_CONF1_SEQ_CONTINUOUS);
> > + }
> > +
> > + if (ams->pl_base) {
> > + /* put sysmon in a soft reset to change the sequence */
> > + ams_pl_update_reg(ams, AMS_REG_CONFIG1,
> AMS_CONF1_SEQ_MASK,
> > + AMS_CONF1_SEQ_DEFAULT);
> > +
> > + /* configure basic channels */
> > + scan_mask = scan_mask >> PS_SEQ_MAX;
> > + writel(scan_mask & AMS_REG_SEQ0_MASK,
> > + ams->pl_base + AMS_REG_SEQ_CH0);
> > + writel(AMS_REG_SEQ2_MASK &
> > + (scan_mask >> AMS_REG_SEQ2_MASK_SHIFT),
> > + ams->pl_base + AMS_REG_SEQ_CH2);
> > + writel(AMS_REG_SEQ1_MASK &
> > + (scan_mask >> AMS_REG_SEQ1_MASK_SHIFT),
> > + ams->pl_base + AMS_REG_SEQ_CH1);
> > +
> > + /* set continuous sequence mode */
> > + ams_pl_update_reg(ams, AMS_REG_CONFIG1,
> AMS_CONF1_SEQ_MASK,
> > + AMS_CONF1_SEQ_CONTINUOUS);
> > + }
> > +}
> > +
> > +static int iio_ams_init_device(struct ams *ams) {
> > + u32 reg;
> > + int ret;
> > +
> > + /* reset AMS */
> > + if (ams->ps_base) {
> > + writel(AMS_PS_RESET_VALUE, ams->ps_base + AMS_VP_VN);
> > +
> > + ret = readl_poll_timeout(ams->base + AMS_PS_CSTS, reg,
> > + (reg & AMS_PS_CSTS_PS_READY) ==
> > + AMS_PS_CSTS_PS_READY, 0,
> > + AMS_INIT_TIMEOUT);
> > + if (ret)
> > + return ret;
> > +
> > + /* put sysmon in a default state */
> > + ams_ps_update_reg(ams, AMS_REG_CONFIG1,
> AMS_CONF1_SEQ_MASK,
> > + AMS_CONF1_SEQ_DEFAULT);
> > + }
> > +
> > + if (ams->pl_base) {
> > + writel(AMS_PL_RESET_VALUE, ams->pl_base + AMS_VP_VN);
> > +
> > + ret = readl_poll_timeout(ams->base + AMS_PL_CSTS, reg,
> > + (reg & AMS_PL_CSTS_ACCESS_MASK)
> ==
> > + AMS_PL_CSTS_ACCESS_MASK, 0,
> > + AMS_INIT_TIMEOUT);
> > + if (ret)
> > + return ret;
> > +
> > + /* put sysmon in a default state */
> > + ams_pl_update_reg(ams, AMS_REG_CONFIG1,
> AMS_CONF1_SEQ_MASK,
> > + AMS_CONF1_SEQ_DEFAULT);
> > + }
> > +
> > + ams_disable_all_alarms(ams);
> > +
> > + /* Disable interrupt */
> > + ams_update_intrmask(ams, ~0, ~0);
> > +
> > + /* Clear any pending interrupt */
> > + writel(AMS_ISR0_ALARM_MASK, ams->base + AMS_ISR_0);
> > + writel(AMS_ISR1_ALARM_MASK, ams->base + AMS_ISR_1);
> > +
> > + return 0;
> > +}
> > +
> > +static int ams_enable_single_channel(struct ams *ams, unsigned int
> > +offset) {
> > + u8 channel_num = 0;
> > +
> > + switch (offset) {
> > + case AMS_VCC_PSPLL0:
> > + channel_num = AMS_VCC_PSPLL0_CH;
> > + break;
> > + case AMS_VCC_PSPLL3:
> > + channel_num = AMS_VCC_PSPLL3_CH;
> > + break;
> > + case AMS_VCCINT:
> > + channel_num = AMS_VCCINT_CH;
> > + break;
> > + case AMS_VCCBRAM:
> > + channel_num = AMS_VCCBRAM_CH;
> > + break;
> > + case AMS_VCCAUX:
> > + channel_num = AMS_VCCAUX_CH;
> > + break;
> > + case AMS_PSDDRPLL:
> > + channel_num = AMS_PSDDRPLL_CH;
> > + break;
> > + case AMS_PSINTFPDDR:
> > + channel_num = AMS_PSINTFPDDR_CH;
> > + break;
> > + default:
> > + return -EINVAL;
> > + }
> > +
> > + /* set single channel, sequencer off mode */
> > + ams_ps_update_reg(ams, AMS_REG_CONFIG1,
> AMS_CONF1_SEQ_MASK,
> > + AMS_CONF1_SEQ_SINGLE_CHANNEL);
> > +
> > + /* write the channel number */
> > + ams_ps_update_reg(ams, AMS_REG_CONFIG0,
> AMS_CONF0_CHANNEL_NUM_MASK,
> > + channel_num);
> > + mdelay(1);
> This delay should be documented.. Preferably with a reference to the
> datasheet to justify the particular value.

There is an option to poll for EOC (End of Conversion) to be set in a register. I will replace this delay will that polling.

>
> > +
> > + return 0;
> > +}
> > +
> > +static int ams_read_vcc_reg(struct ams *ams, unsigned int offset, u32
> > +*data) {
> > + int ret;
> > +
> > + ret = ams_enable_single_channel(ams, offset);
> > + if (ret)
> > + return ret;
> > +
> > + *data = readl(ams->base + offset);
> > + ams_enable_channel_sequence(ams);
> > +
> > + return 0;
> > +}
> > +
> > +static int ams_read_raw(struct iio_dev *indio_dev,
> > + struct iio_chan_spec const *chan,
> > + int *val, int *val2, long mask)
> > +{
> > + struct ams *ams = iio_priv(indio_dev);
> > + int ret;
> > +
> > + switch (mask) {
> > + case IIO_CHAN_INFO_RAW:
> > + mutex_lock(&ams->mutex);
> > + if (chan->scan_index >= (PS_SEQ_MAX * 3)) {
> > + ret = ams_read_vcc_reg(ams, chan->address, val);
> > + if (ret)
> > + goto read_raw_err;
>
> Missing mutex_unlock?

Missed it. This will be corrected in v2.

>
> > + } else if (chan->scan_index >= PS_SEQ_MAX)
> > + *val = readl(ams->pl_base + chan->address);
> > + else
> > + *val = readl(ams->ps_base + chan->address);
> > + mutex_unlock(&ams->mutex);
> > +
> > + return IIO_VAL_INT;
> > + case IIO_CHAN_INFO_SCALE:
> > + switch (chan->type) {
> > + case IIO_VOLTAGE:
> > + switch (chan->address) {
> > + case AMS_SUPPLY1:
> > + case AMS_SUPPLY2:
> > + case AMS_SUPPLY3:
> > + case AMS_SUPPLY4:
> > + *val = AMS_SUPPLY_SCALE_3VOLT;
> > + break;
> > + case AMS_SUPPLY5:
> > + case AMS_SUPPLY6:
> > + if (chan->scan_index < PS_SEQ_MAX)
> > + *val = AMS_SUPPLY_SCALE_6VOLT;
> > + else
> > + *val = AMS_SUPPLY_SCALE_3VOLT;
> > + break;
> > + case AMS_SUPPLY7:
> > + case AMS_SUPPLY8:
> > + *val = AMS_SUPPLY_SCALE_6VOLT;
> > + break;
> > + case AMS_SUPPLY9:
> > + case AMS_SUPPLY10:
> > + if (chan->scan_index < PS_SEQ_MAX)
> > + *val = AMS_SUPPLY_SCALE_3VOLT;
> > + else
> > + *val = AMS_SUPPLY_SCALE_6VOLT;
> > + break;
> > + case AMS_VCC_PSPLL0:
> > + case AMS_VCC_PSPLL3:
> > + case AMS_VCCINT:
> > + case AMS_VCCBRAM:
> > + case AMS_VCCAUX:
> > + case AMS_PSDDRPLL:
> > + case AMS_PSINTFPDDR:
> > + *val = AMS_SUPPLY_SCALE_3VOLT;
> > + break;
> > + default:
> > + *val = AMS_SUPPLY_SCALE_1VOLT;
> > + break;
> > + }
> > + *val2 = AMS_SUPPLY_SCALE_DIV_BIT;
> > + return IIO_VAL_FRACTIONAL_LOG2;
> > + case IIO_TEMP:
> > + *val = AMS_TEMP_SCALE;
> > + *val2 = AMS_TEMP_SCALE_DIV_BIT;
> > + return IIO_VAL_FRACTIONAL_LOG2;
> > + default:
> > + return -EINVAL;
> > + }
> > + case IIO_CHAN_INFO_OFFSET:
> > + /* Only the temperature channel has an offset */
> > + *val = AMS_TEMP_OFFSET;
> > + return IIO_VAL_INT;
> > + }
> > +
> > +read_raw_err:
>
> Given we only return an error code here, are we not better just doing that
> inline?

Yes. You are right. Will update this in v2.

>
> > + return -EINVAL;
> > +}
> > +
> > +static int ams_get_alarm_offset(int scan_index, enum
> > +iio_event_direction dir) {
> > + int offset = 0;
> > +
> > + if (scan_index >= PS_SEQ_MAX)
> > + scan_index -= PS_SEQ_MAX;
> > +
> > + if (dir == IIO_EV_DIR_FALLING) {
> > + if (scan_index < AMS_SEQ_SUPPLY7)
> > + offset = AMS_ALARM_THRESHOLD_OFF_10;
> > + else
> > + offset = AMS_ALARM_THRESHOLD_OFF_20;
> > + }
> > +
> > + switch (scan_index) {
> > + case AMS_SEQ_TEMP:
> > + return AMS_ALARM_TEMP + offset;
> > + case AMS_SEQ_SUPPLY1:
> > + return AMS_ALARM_SUPPLY1 + offset;
> > + case AMS_SEQ_SUPPLY2:
> > + return AMS_ALARM_SUPPLY2 + offset;
> > + case AMS_SEQ_SUPPLY3:
> > + return AMS_ALARM_SUPPLY3 + offset;
> > + case AMS_SEQ_SUPPLY4:
> > + return AMS_ALARM_SUPPLY4 + offset;
> > + case AMS_SEQ_SUPPLY5:
> > + return AMS_ALARM_SUPPLY5 + offset;
> > + case AMS_SEQ_SUPPLY6:
> > + return AMS_ALARM_SUPPLY6 + offset;
> > + case AMS_SEQ_SUPPLY7:
> > + return AMS_ALARM_SUPPLY7 + offset;
> > + case AMS_SEQ_SUPPLY8:
> > + return AMS_ALARM_SUPPLY8 + offset;
> > + case AMS_SEQ_SUPPLY9:
> > + return AMS_ALARM_SUPPLY9 + offset;
> > + case AMS_SEQ_SUPPLY10:
> > + return AMS_ALARM_SUPPLY10 + offset;
> > + case AMS_SEQ_VCCAMS:
> > + return AMS_ALARM_VCCAMS + offset;
> > + case AMS_SEQ_TEMP_REMOTE:
> > + return AMS_ALARM_TEMP_REMOTE + offset;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static const struct iio_chan_spec *ams_event_to_channel(
> > + struct iio_dev *indio_dev, u32 event) {
> > + int scan_index = 0, i;
> > +
> > + if (event >= AMS_PL_ALARM_START) {
> > + event -= AMS_PL_ALARM_START;
> > + scan_index = PS_SEQ_MAX;
> > + }
> > +
> > + switch (event) {
> > + case AMS_ALARM_BIT_TEMP:
> > + scan_index += AMS_SEQ_TEMP;
> > + break;
> > + case AMS_ALARM_BIT_SUPPLY1:
> > + scan_index += AMS_SEQ_SUPPLY1;
> > + break;
> > + case AMS_ALARM_BIT_SUPPLY2:
> > + scan_index += AMS_SEQ_SUPPLY2;
> > + break;
> > + case AMS_ALARM_BIT_SUPPLY3:
> > + scan_index += AMS_SEQ_SUPPLY3;
> > + break;
> > + case AMS_ALARM_BIT_SUPPLY4:
> > + scan_index += AMS_SEQ_SUPPLY4;
> > + break;
> > + case AMS_ALARM_BIT_SUPPLY5:
> > + scan_index += AMS_SEQ_SUPPLY5;
> > + break;
> > + case AMS_ALARM_BIT_SUPPLY6:
> > + scan_index += AMS_SEQ_SUPPLY6;
> > + break;
> > + case AMS_ALARM_BIT_SUPPLY7:
> > + scan_index += AMS_SEQ_SUPPLY7;
> > + break;
> > + case AMS_ALARM_BIT_SUPPLY8:
> > + scan_index += AMS_SEQ_SUPPLY8;
> > + break;
> > + case AMS_ALARM_BIT_SUPPLY9:
> > + scan_index += AMS_SEQ_SUPPLY9;
> > + break;
> > + case AMS_ALARM_BIT_SUPPLY10:
> > + scan_index += AMS_SEQ_SUPPLY10;
> > + break;
> > + case AMS_ALARM_BIT_VCCAMS:
> > + scan_index += AMS_SEQ_VCCAMS;
> > + break;
> > + case AMS_ALARM_BIT_TEMP_REMOTE:
> > + scan_index += AMS_SEQ_TEMP_REMOTE;
> > + break;
> > + }
> > +
> > + for (i = 0; i < indio_dev->num_channels; i++)
> > + if (indio_dev->channels[i].scan_index == scan_index)
> > + break;
> > +
> > + return &indio_dev->channels[i];
> > +}
> > +
> > +static int ams_get_alarm_mask(int scan_index) {
> > + int bit = 0;
> > +
> > + if (scan_index >= PS_SEQ_MAX) {
> > + bit = AMS_PL_ALARM_START;
> > + scan_index -= PS_SEQ_MAX;
> > + }
> > +
> > + switch (scan_index) {
> > + case AMS_SEQ_TEMP:
> > + return BIT(AMS_ALARM_BIT_TEMP + bit);
> > + case AMS_SEQ_SUPPLY1:
> > + return BIT(AMS_ALARM_BIT_SUPPLY1 + bit);
> > + case AMS_SEQ_SUPPLY2:
> > + return BIT(AMS_ALARM_BIT_SUPPLY2 + bit);
> > + case AMS_SEQ_SUPPLY3:
> > + return BIT(AMS_ALARM_BIT_SUPPLY3 + bit);
> > + case AMS_SEQ_SUPPLY4:
> > + return BIT(AMS_ALARM_BIT_SUPPLY4 + bit);
> > + case AMS_SEQ_SUPPLY5:
> > + return BIT(AMS_ALARM_BIT_SUPPLY5 + bit);
> > + case AMS_SEQ_SUPPLY6:
> > + return BIT(AMS_ALARM_BIT_SUPPLY6 + bit);
> > + case AMS_SEQ_SUPPLY7:
> > + return BIT(AMS_ALARM_BIT_SUPPLY7 + bit);
> > + case AMS_SEQ_SUPPLY8:
> > + return BIT(AMS_ALARM_BIT_SUPPLY8 + bit);
> > + case AMS_SEQ_SUPPLY9:
> > + return BIT(AMS_ALARM_BIT_SUPPLY9 + bit);
> > + case AMS_SEQ_SUPPLY10:
> > + return BIT(AMS_ALARM_BIT_SUPPLY10 + bit);
> > + case AMS_SEQ_VCCAMS:
> > + return BIT(AMS_ALARM_BIT_VCCAMS + bit);
> > + case AMS_SEQ_TEMP_REMOTE:
> > + return BIT(AMS_ALARM_BIT_TEMP_REMOTE + bit);
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static int ams_read_event_config(struct iio_dev *indio_dev,
> > + const struct iio_chan_spec *chan,
> > + enum iio_event_type type,
> > + enum iio_event_direction dir)
> > +{
> > + struct ams *ams = iio_priv(indio_dev);
> > +
> > + return (ams->alarm_mask & ams_get_alarm_mask(chan->scan_index))
> ? 1
> > +: 0; }
> > +
> > +static int ams_write_event_config(struct iio_dev *indio_dev,
> > + const struct iio_chan_spec *chan,
> > + enum iio_event_type type,
> > + enum iio_event_direction dir,
> > + int state)
> > +{
> > + struct ams *ams = iio_priv(indio_dev);
> > + unsigned int alarm;
> > +
> > + alarm = ams_get_alarm_mask(chan->scan_index);
> > +
> > + mutex_lock(&ams->mutex);
> > +
> > + if (state)
> > + ams->alarm_mask |= alarm;
> > + else
> > + ams->alarm_mask &= ~alarm;
> > +
> > + iio_ams_update_alarm(ams, ams->alarm_mask);
> > +
> > + mutex_unlock(&ams->mutex);
> > +
> > + return 0;
> > +}
> > +
> > +static int ams_read_event_value(struct iio_dev *indio_dev,
> > + const struct iio_chan_spec *chan,
> > + enum iio_event_type type,
> > + enum iio_event_direction dir,
> > + enum iio_event_info info, int *val, int *val2) {
> > + struct ams *ams = iio_priv(indio_dev);
> > + unsigned int offset = ams_get_alarm_offset(chan->scan_index, dir);
> > +
> > + mutex_lock(&ams->mutex);
> > +
> > + if (chan->scan_index >= PS_SEQ_MAX)
> > + *val = readl(ams->pl_base + offset);
> > + else
> > + *val = readl(ams->ps_base + offset);
> > +
> > + mutex_unlock(&ams->mutex);
> > +
> > + return IIO_VAL_INT;
> > +}
> > +
> > +static int ams_write_event_value(struct iio_dev *indio_dev,
> > + const struct iio_chan_spec *chan,
> > + enum iio_event_type type,
> > + enum iio_event_direction dir,
> > + enum iio_event_info info, int val, int val2) {
> > + struct ams *ams = iio_priv(indio_dev);
> > + unsigned int offset;
> > +
> > + mutex_lock(&ams->mutex);
> > +
> > + /* Set temperature channel threshold to direct threshold */
> > + if (chan->type == IIO_TEMP) {
> > + offset = ams_get_alarm_offset(chan->scan_index,
> > + IIO_EV_DIR_FALLING);
> > +
> > + if (chan->scan_index >= PS_SEQ_MAX)
> > + ams_pl_update_reg(ams, offset,
> > + AMS_ALARM_THR_DIRECT_MASK,
> > + AMS_ALARM_THR_DIRECT_MASK);
> > + else
> > + ams_ps_update_reg(ams, offset,
> > + AMS_ALARM_THR_DIRECT_MASK,
> > + AMS_ALARM_THR_DIRECT_MASK);
> > + }
> > +
> > + offset = ams_get_alarm_offset(chan->scan_index, dir);
> > + if (chan->scan_index >= PS_SEQ_MAX)
> > + writel(val, ams->pl_base + offset);
> > + else
> > + writel(val, ams->ps_base + offset);
> > +
> > + mutex_unlock(&ams->mutex);
> > +
> > + return 0;
> > +}
> > +
> > +static void ams_handle_event(struct iio_dev *indio_dev, u32 event) {
> > + const struct iio_chan_spec *chan;
> > +
> > + chan = ams_event_to_channel(indio_dev, event);
> > +
> > + if (chan->type == IIO_TEMP) {
> > + /* The temperature channel only supports over-temperature
> In IIO we use the standard kernel syntax for comments of
> /*
> * The temperature...
> */
>
> This form is only used in a few subsystems such as net.
>
> It's minor but nice to be consistent...

Okay. Will update this in v2.

>
> > + * events
> > + */
> > + iio_push_event(indio_dev,
> > + IIO_UNMOD_EVENT_CODE(chan->type, chan-
> >channel,
> > + IIO_EV_TYPE_THRESH,
> > + IIO_EV_DIR_RISING),
> > + iio_get_time_ns(indio_dev));
> > + } else {
> > + /* For other channels we don't know whether it is a upper or
> > + * lower threshold event. Userspace will have to check the
> > + * channel value if it wants to know.
> > + */
> > + iio_push_event(indio_dev,
> > + IIO_UNMOD_EVENT_CODE(chan->type, chan-
> >channel,
> > + IIO_EV_TYPE_THRESH,
> > + IIO_EV_DIR_EITHER),
> > + iio_get_time_ns(indio_dev));
> > + }
> > +}
> > +
> > +static void ams_handle_events(struct iio_dev *indio_dev, unsigned
> > +long events) {
> > + unsigned int bit;
> > +
> > + for_each_set_bit(bit, &events, AMS_NO_OF_ALARMS)
> > + ams_handle_event(indio_dev, bit);
> > +}
> > +
> > +/**
> > + * ams_unmask_worker - ams alarm interrupt unmask worker
> > + * @work : work to be done
> > + *
> > + * The ZynqMP threshold interrupts are level sensitive. Since we
> > +can't make the
> > + * threshold condition go way from within the interrupt handler, this
> > +means as
> > + * soon as a threshold condition is present we would enter the
> > +interrupt handler
> > + * again and again. To work around this we mask all active threshold
> > +interrupts
> > + * in the interrupt handler and start a timer. In this timer we poll
> > +the
> > + * interrupt status and only if the interrupt is inactive we unmask it again.
> > + */
> > +static void ams_unmask_worker(struct work_struct *work) {
> > + struct ams *ams = container_of(work, struct ams,
> ams_unmask_work.work);
> > + unsigned int status, unmask;
> > +
> > + spin_lock_irq(&ams->lock);
> > +
> > + status = readl(ams->base + AMS_ISR_0);
> > +
> > + /* Clear those bits which are not active anymore */
> > + unmask = (ams->masked_alarm ^ status) & ams->masked_alarm;
> > +
> > + /* clear status of disabled alarm */
> > + unmask |= ams->intr_mask;
> > +
> > + ams->masked_alarm &= status;
> > +
> > + /* Also clear those which are masked out anyway */
> > + ams->masked_alarm &= ~ams->intr_mask;
> > +
> > + /* Clear the interrupts before we unmask them */
> > + writel(unmask, ams->base + AMS_ISR_0);
> > +
> > + ams_update_intrmask(ams, 0, 0);
> > +
> > + spin_unlock_irq(&ams->lock);
> > +
> > + /* if still pending some alarm re-trigger the timer */
> > + if (ams->masked_alarm)
> > + schedule_delayed_work(&ams->ams_unmask_work,
> > +
> msecs_to_jiffies(AMS_UNMASK_TIMEOUT_MS));
> > +}
> > +
> > +static irqreturn_t ams_iio_irq(int irq, void *data) {
> > + unsigned int isr0, isr1;
> > + struct iio_dev *indio_dev = data;
> > + struct ams *ams = iio_priv(indio_dev);
> > +
> > + spin_lock(&ams->lock);
>
> Do these need to be handled in interrupt context? Would we be better off
> doing it in an interrupt thread where we can sleep (and hence not use a spin
> lock for example)?
>
> Perhaps not, but this doesn't immediately feel time critical...

This is not time critical. I will remove spin lock here.

>
> > +
> > + isr0 = readl(ams->base + AMS_ISR_0);
> > + isr1 = readl(ams->base + AMS_ISR_1);
> > +
> > + /* only process alarms that are not masked */
> > + isr0 &= ~((ams->intr_mask & AMS_ISR0_ALARM_MASK) | ams-
> >masked_alarm);
> > + isr1 &= ~(ams->intr_mask >> AMS_ISR1_INTR_MASK_SHIFT);
> > +
> > + /* clear interrupt */
> > + writel(isr0, ams->base + AMS_ISR_0);
> > + writel(isr1, ams->base + AMS_ISR_1);
>
> If we have interrupts here that aren't ours we should a) not be clearing them
> b) be returning IRQ_NONE so it can be handled as an incorrect interrupt and
> reported as such.

Right. Will update this in v2.

>
> > +
> > + if (isr0) {
> > + /* Once the alarm interrupt occurred, mask until get cleared
> */
> > + ams->masked_alarm |= isr0;
> > + ams_update_intrmask(ams, 0, 0);
> > +
> > + ams_handle_events(indio_dev, isr0);
> > +
> > + schedule_delayed_work(&ams->ams_unmask_work,
> > +
> msecs_to_jiffies(AMS_UNMASK_TIMEOUT_MS));
> > + }
> > +
> > + spin_unlock(&ams->lock);
> > +
> > + return IRQ_HANDLED;
> > +}
> > +
> > +static const struct iio_event_spec ams_temp_events[] = {
> > + {
> > + .type = IIO_EV_TYPE_THRESH,
> > + .dir = IIO_EV_DIR_RISING,
> > + .mask_separate = BIT(IIO_EV_INFO_ENABLE) |
> > + BIT(IIO_EV_INFO_VALUE),
> > + },
> > +};
> > +
> > +static const struct iio_event_spec ams_voltage_events[] = {
> > + {
> > + .type = IIO_EV_TYPE_THRESH,
> > + .dir = IIO_EV_DIR_RISING,
> > + .mask_separate = BIT(IIO_EV_INFO_VALUE),
> > + }, {
> > + .type = IIO_EV_TYPE_THRESH,
> > + .dir = IIO_EV_DIR_FALLING,
> > + .mask_separate = BIT(IIO_EV_INFO_VALUE),
> > + }, {
> > + .type = IIO_EV_TYPE_THRESH,
> > + .dir = IIO_EV_DIR_EITHER,
> > + .mask_separate = BIT(IIO_EV_INFO_ENABLE),
> > + },
> > +};
> > +
> > +static const struct iio_chan_spec ams_ps_channels[] = {
> > + AMS_PS_CHAN_TEMP(AMS_SEQ_TEMP, AMS_TEMP, "ps_temp"),
> > + AMS_PS_CHAN_TEMP(AMS_SEQ_TEMP_REMOTE,
> AMS_TEMP_REMOTE, "remote_temp"),
> > + AMS_PS_CHAN_VOLTAGE(AMS_SEQ_SUPPLY1, AMS_SUPPLY1,
> "vccpsintlp"),
> > + AMS_PS_CHAN_VOLTAGE(AMS_SEQ_SUPPLY2, AMS_SUPPLY2,
> "vccpsintfp"),
> > + AMS_PS_CHAN_VOLTAGE(AMS_SEQ_SUPPLY3, AMS_SUPPLY3,
> "vccpsaux"),
> > + AMS_PS_CHAN_VOLTAGE(AMS_SEQ_SUPPLY4, AMS_SUPPLY4,
> "vccpsddr"),
> > + AMS_PS_CHAN_VOLTAGE(AMS_SEQ_SUPPLY5, AMS_SUPPLY5,
> "vccpsio3"),
> > + AMS_PS_CHAN_VOLTAGE(AMS_SEQ_SUPPLY6, AMS_SUPPLY6,
> "vccpsio0"),
> > + AMS_PS_CHAN_VOLTAGE(AMS_SEQ_SUPPLY7, AMS_SUPPLY7,
> "vccpsio1"),
> > + AMS_PS_CHAN_VOLTAGE(AMS_SEQ_SUPPLY8, AMS_SUPPLY8,
> "vccpsio2"),
> > + AMS_PS_CHAN_VOLTAGE(AMS_SEQ_SUPPLY9, AMS_SUPPLY9,
> "psmgtravcc"),
> > + AMS_PS_CHAN_VOLTAGE(AMS_SEQ_SUPPLY10, AMS_SUPPLY10,
> "psmgtravtt"),
> > + AMS_PS_CHAN_VOLTAGE(AMS_SEQ_VCCAMS, AMS_VCCAMS,
> "vccams"), };
> > +
> > +static const struct iio_chan_spec ams_pl_channels[] = {
> > + AMS_PL_CHAN_TEMP(AMS_SEQ_TEMP, AMS_TEMP, "pl_temp"),
> > + AMS_PL_CHAN_VOLTAGE(AMS_SEQ_SUPPLY1, AMS_SUPPLY1, "vccint",
> true),
> > + AMS_PL_CHAN_VOLTAGE(AMS_SEQ_SUPPLY2, AMS_SUPPLY2,
> "vccaux", true),
> > + AMS_PL_CHAN_VOLTAGE(AMS_SEQ_VREFP, AMS_VREFP, "vccvrefp",
> false),
> > + AMS_PL_CHAN_VOLTAGE(AMS_SEQ_VREFN, AMS_VREFN, "vccvrefn",
> false),
> > + AMS_PL_CHAN_VOLTAGE(AMS_SEQ_SUPPLY3, AMS_SUPPLY3,
> "vccbram", true),
> > + AMS_PL_CHAN_VOLTAGE(AMS_SEQ_SUPPLY4, AMS_SUPPLY4,
> "vccplintlp", true),
> > + AMS_PL_CHAN_VOLTAGE(AMS_SEQ_SUPPLY5, AMS_SUPPLY5,
> "vccplintfp", true),
> > + AMS_PL_CHAN_VOLTAGE(AMS_SEQ_SUPPLY6, AMS_SUPPLY6,
> "vccplaux", true),
> > + AMS_PL_CHAN_VOLTAGE(AMS_SEQ_VCCAMS, AMS_VCCAMS,
> "vccams", true),
> > + AMS_PL_CHAN_VOLTAGE(AMS_SEQ_VP_VN, AMS_VP_VN, "vccvpvn",
> false),
> > + AMS_PL_CHAN_VOLTAGE(AMS_SEQ_SUPPLY7, AMS_SUPPLY7,
> "vuser0", true),
> > + AMS_PL_CHAN_VOLTAGE(AMS_SEQ_SUPPLY8, AMS_SUPPLY8,
> "vuser1", true),
> > + AMS_PL_CHAN_VOLTAGE(AMS_SEQ_SUPPLY9, AMS_SUPPLY9,
> "vuser2", true),
> > + AMS_PL_CHAN_VOLTAGE(AMS_SEQ_SUPPLY10, AMS_SUPPLY10,
> "vuser3", true),
> > + AMS_PL_AUX_CHAN_VOLTAGE(0, "vccaux0"),
>
> Extended_name is a two edged sword. It lets you make nice specifically named
> channels, but it also breaks almost all userspace code as it doesn't know how to
> handle the extra bit on the end of the name.
>
> As such we tend to only specify it for very special use non standard channels
> (such as the power supplies)
>
> For the aux channels, it has no particular meaning. So I would prefer that you
> dropped it and just left them with the indexes.

Okay. I will keep the extended names for AMS_SUPPLY* and remove them for the aux channels.

>
> > + AMS_PL_AUX_CHAN_VOLTAGE(1, "vccaux1"),
> > + AMS_PL_AUX_CHAN_VOLTAGE(2, "vccaux2"),
> > + AMS_PL_AUX_CHAN_VOLTAGE(3, "vccaux3"),
> > + AMS_PL_AUX_CHAN_VOLTAGE(4, "vccaux4"),
> > + AMS_PL_AUX_CHAN_VOLTAGE(5, "vccaux5"),
> > + AMS_PL_AUX_CHAN_VOLTAGE(6, "vccaux6"),
> > + AMS_PL_AUX_CHAN_VOLTAGE(7, "vccaux7"),
> > + AMS_PL_AUX_CHAN_VOLTAGE(8, "vccaux8"),
> > + AMS_PL_AUX_CHAN_VOLTAGE(9, "vccaux9"),
> > + AMS_PL_AUX_CHAN_VOLTAGE(10, "vccaux10"),
> > + AMS_PL_AUX_CHAN_VOLTAGE(11, "vccaux11"),
> > + AMS_PL_AUX_CHAN_VOLTAGE(12, "vccaux12"),
> > + AMS_PL_AUX_CHAN_VOLTAGE(13, "vccaux13"),
> > + AMS_PL_AUX_CHAN_VOLTAGE(14, "vccaux14"),
> > + AMS_PL_AUX_CHAN_VOLTAGE(15, "vccaux15"), };
> > +
> > +static const struct iio_chan_spec ams_ctrl_channels[] = {
> > + AMS_CTRL_CHAN_VOLTAGE(AMS_SEQ_VCC_PSPLL, AMS_VCC_PSPLL0,
> "vcc_pspll0"),
> > + AMS_CTRL_CHAN_VOLTAGE(AMS_SEQ_VCC_PSBATT,
> AMS_VCC_PSPLL3, "vcc_psbatt"),
> > + AMS_CTRL_CHAN_VOLTAGE(AMS_SEQ_VCCINT, AMS_VCCINT,
> "vccint"),
> > + AMS_CTRL_CHAN_VOLTAGE(AMS_SEQ_VCCBRAM, AMS_VCCBRAM,
> "vccbram"),
> > + AMS_CTRL_CHAN_VOLTAGE(AMS_SEQ_VCCAUX, AMS_VCCAUX,
> "vccaux"),
> > + AMS_CTRL_CHAN_VOLTAGE(AMS_SEQ_PSDDRPLL, AMS_PSDDRPLL,
> "psddrpll"),
> > + AMS_CTRL_CHAN_VOLTAGE(AMS_SEQ_INTDDR, AMS_PSINTFPDDR,
> "psintfpddr"),
> > +};
> > +
> > +static int ams_init_module(struct iio_dev *indio_dev, struct device_node
> *np,
> > + struct iio_chan_spec *channels) {
> > + struct ams *ams = iio_priv(indio_dev);
> > + struct device_node *chan_node, *child;
> > + int ret, num_channels = 0;
> > + unsigned int reg;
> > +
> > + if (of_device_is_compatible(np, "xlnx,zynqmp-ams-ps")) {
> > + ams->ps_base = of_iomap(np, 0);
> > + if (!ams->ps_base)
> > + return -ENXIO;
> > +
> > + /* add PS channels to iio device channels */
> > + memcpy(channels + num_channels, ams_ps_channels,
> > + sizeof(ams_ps_channels));
> > + num_channels += ARRAY_SIZE(ams_ps_channels);
> > + } else if (of_device_is_compatible(np, "xlnx,zynqmp-ams-pl")) {
> > + ams->pl_base = of_iomap(np, 0);
> > + if (!ams->pl_base)
> > + return -ENXIO;
> > +
> > + /* Copy only first 10 fix channels */
> > + memcpy(channels + num_channels, ams_pl_channels,
> > + AMS_PL_MAX_FIXED_CHANNEL * sizeof(*channels));
> > + num_channels += AMS_PL_MAX_FIXED_CHANNEL;
> > +
> > + chan_node = of_get_child_by_name(np, "xlnx,ext-channels");
> > + if (chan_node) {
> > + for_each_child_of_node(chan_node, child) {
> > + ret = of_property_read_u32(child, "reg",
> &reg);
> > + if (ret || reg > AMS_PL_MAX_EXT_CHANNEL)
> > + continue;
> > +
> > + memcpy(&channels[num_channels],
> > + &ams_pl_channels[reg +
> > + AMS_PL_MAX_FIXED_CHANNEL],
> > + sizeof(*channels));
> > +
> > + if (of_property_read_bool(child,
> > + "xlnx,bipolar"))
> > +
> channels[num_channels].scan_type.sign =
> > + 's';
> > +
> > + num_channels += 1;
>
> num_channels++;

Okay.

>
> > + }
> > + }
> > + of_node_put(chan_node);
> > + } else if (of_device_is_compatible(np, "xlnx,zynqmp-ams")) {
> > + /* add AMS channels to iio device channels */
> > + memcpy(channels + num_channels, ams_ctrl_channels,
> > + sizeof(ams_ctrl_channels));
> > + num_channels += ARRAY_SIZE(ams_ctrl_channels);
> > + } else {
> > + return -EINVAL;
> > + }
> > +
> > + return num_channels;
> > +}
> > +
> > +static int ams_parse_dt(struct iio_dev *indio_dev, struct
> > +platform_device *pdev) {
> > + struct ams *ams = iio_priv(indio_dev);
> > + struct iio_chan_spec *ams_channels, *dev_channels;
> > + struct device_node *child_node = NULL, *np = pdev->dev.of_node;
> > + int ret, chan_vol = 0, chan_temp = 0, i, rising_off, falling_off;
>
> chan_vol and chan_temp are counts? Perhaps their names can make that
> clearer.

Okay. I will change their name to 'vol_ch_cnt' and 'temp_ch_cnt' in v2.

>
> > + unsigned int num_channels = 0;
> > +
> > + /* Initialize buffer for channel specification */
> > + ams_channels = kzalloc(sizeof(ams_ps_channels) +
> > + sizeof(ams_pl_channels) +
> > + sizeof(ams_ctrl_channels), GFP_KERNEL);
> > + if (!ams_channels)
> > + return -ENOMEM;
> > +
> > + if (of_device_is_available(np)) {
> > + ret = ams_init_module(indio_dev, np, ams_channels);
> > + if (ret < 0) {
> > + kfree(ams_channels);
> > + return ret;
> > + }
> > +
> > + num_channels += ret;
> > + }
> > +
> > + for_each_child_of_node(np, child_node) {
> > + if (of_device_is_available(child_node)) {
> > + ret = ams_init_module(indio_dev, child_node,
> > + ams_channels + num_channels);
> > + if (ret < 0) {
> > + kfree(ams_channels);
> > + return ret;
> > + }
> > +
> > + num_channels += ret;
> > + }
> > + }
> > +
> > + for (i = 0; i < num_channels; i++) {
> > + if (ams_channels[i].type == IIO_VOLTAGE)
> > + ams_channels[i].channel = chan_vol++;
> > + else
> > + ams_channels[i].channel = chan_temp++;
> > +
> > + if (ams_channels[i].scan_index < (PS_SEQ_MAX * 3)) {
> > + /* set threshold to max and min for each channel */
> > + falling_off = ams_get_alarm_offset(
> > + ams_channels[i].scan_index,
> > + IIO_EV_DIR_FALLING);
> > + rising_off = ams_get_alarm_offset(
> > + ams_channels[i].scan_index,
> > + IIO_EV_DIR_RISING);
> > + if (ams_channels[i].scan_index >= PS_SEQ_MAX) {
> > + writel(AMS_ALARM_THR_MIN,
> > + ams->pl_base + falling_off);
> > + writel(AMS_ALARM_THR_MAX,
> > + ams->pl_base + rising_off);
> > + } else {
> > + writel(AMS_ALARM_THR_MIN,
> > + ams->ps_base + falling_off);
> > + writel(AMS_ALARM_THR_MAX,
> > + ams->ps_base + rising_off);
> > + }
> > + }
> > + }
> > +
> > + dev_channels = devm_kzalloc(&pdev->dev, sizeof(*dev_channels) *
> > + num_channels, GFP_KERNEL);
> > + if (!dev_channels) {
> > + kfree(ams_channels);
> > + return -ENOMEM;
> > + }
> > +
> > + memcpy(dev_channels, ams_channels,
> > + sizeof(*ams_channels) * num_channels);
> > + kfree(ams_channels);
> If you were to reorder this so the ams_channels cleanup was last you could use
> the nice clean pattern of
>
> error:
> kfree(ams_channels);
>
> return ret;
>
> To make it clear that the ams_channels gets freed in all paths.

Fair enough. I will update this in v2.

>
> > + indio_dev->channels = dev_channels;
> > + indio_dev->num_channels = num_channels;
> > +
> > + return 0;
> > +}
> > +
> > +static const struct iio_info iio_pl_info = {
> > + .read_raw = &ams_read_raw,
> > + .read_event_config = &ams_read_event_config,
> > + .write_event_config = &ams_write_event_config,
> > + .read_event_value = &ams_read_event_value,
> > + .write_event_value = &ams_write_event_value, };
> > +
> > +static const struct of_device_id ams_of_match_table[] = {
> > + { .compatible = "xlnx,zynqmp-ams" },
> > + { }
> > +};
> > +MODULE_DEVICE_TABLE(of, ams_of_match_table);
> > +
> > +static int ams_probe(struct platform_device *pdev) {
> > + struct iio_dev *indio_dev;
> > + struct ams *ams;
> > + struct resource *res;
> > + int ret;
> > +
> > + if (!pdev->dev.of_node)
> > + return -ENODEV;
> > +
> > + indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*ams));
> > + if (!indio_dev)
> > + return -ENOMEM;
> > +
> > + ams = iio_priv(indio_dev);
> > + mutex_init(&ams->mutex);
> > + spin_lock_init(&ams->lock);
> > +
> > + indio_dev->dev.parent = &pdev->dev;
> > + indio_dev->dev.of_node = pdev->dev.of_node;
> > + indio_dev->name = "ams";
> As names go, that one is a too little generic. Particularly with a common
> manufacturer of ADCs called Austrian Micro Systems ;) No possibility of
> confusion!
>
> It's fine to use ams within the driver, but for external interfaces, perhaps prefix
> with xilinx-?

Okay. I will use xilinx-ams.

>
> > +
> > + indio_dev->info = &iio_pl_info;
> > + indio_dev->modes = INDIO_DIRECT_MODE;
> > +
> > + res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
> "ams-base");
> > + ams->base = devm_ioremap_resource(&pdev->dev, res);
> > + if (IS_ERR(ams->base))
> > + return PTR_ERR(ams->base);
> > +
> > + INIT_DELAYED_WORK(&ams->ams_unmask_work,
> ams_unmask_worker);
> > +
> > + ams->clk = devm_clk_get(&pdev->dev, NULL);
> > + if (IS_ERR(ams->clk))
> > + return PTR_ERR(ams->clk);
> > + clk_prepare_enable(ams->clk);
> > +
> > + ret = iio_ams_init_device(ams);
> > + if (ret) {
> > + dev_err(&pdev->dev, "failed to initialize AMS\n");
> > + goto clk_disable;
> > + }
> > +
> > + ret = ams_parse_dt(indio_dev, pdev);
> > + if (ret) {
> > + dev_err(&pdev->dev, "failure in parsing DT\n");
> > + goto clk_disable;
> > + }
> > +
> > + ams_enable_channel_sequence(ams);
> > +
> > + ams->irq = platform_get_irq_byname(pdev, "ams-irq");
>
> Why store this in the ams structure? It's not used anywhere other than in the
> next line.

Okay. Will update this in v2.

>
> > + ret = devm_request_irq(&pdev->dev, ams->irq, &ams_iio_irq, 0, "ams-
> irq",
> > + indio_dev);
> This mixing of devm and non devm functions makes it tricky to be sure there
> aren't an races.
>
> One easy solution is to use devm_add_action to put the clk_disable_unprepare
> into the cleanup list.

Okay.

>
> > + if (ret < 0) {
> > + dev_err(&pdev->dev, "failed to register interrupt\n");
> > + goto clk_disable;
> > + }
> > +
> > + platform_set_drvdata(pdev, indio_dev);
> > +
> > + return iio_device_register(indio_dev);
>
> What if device register returns an error? You leave the clock enabled.
>
> That way everything is using the managed cleanup and the ordering will be
> correct.
>
> The alternative is to not use devm forms for everything after the
> clk_prepare_enable.

Yes. This is better.

>
> > +
> > +clk_disable:
> > + clk_disable_unprepare(ams->clk);
> > +
> > + return ret;
> > +}
> > +
> > +static int ams_remove(struct platform_device *pdev) {
> > + struct iio_dev *indio_dev = platform_get_drvdata(pdev);
> > + struct ams *ams = iio_priv(indio_dev);
> > +
> > + cancel_delayed_work(&ams->ams_unmask_work);
> > +
> > + /* Unregister the device */
> > + iio_device_unregister(indio_dev);
> > + clk_disable_unprepare(ams->clk);
> > +
> > + return 0;
> > +}
> > +
> > +static int __maybe_unused ams_suspend(struct device *dev) {
> > + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> > + struct ams *ams = iio_priv(indio_dev);
> > +
> > + clk_disable_unprepare(ams->clk);
> > +
> > + return 0;
> > +}
> > +
> > +static int __maybe_unused ams_resume(struct device *dev) {
> > + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> > + struct ams *ams = iio_priv(indio_dev);
> You could streamline this without loss of clarity as.
>
> struct ams *ams = iio_priv(dev_get_drvdata(dev));
>
> (very minor point!)

Okay.

> > +
> > + clk_prepare_enable(ams->clk);
> > +
> > + return 0;
> > +}
> > +
> > +static SIMPLE_DEV_PM_OPS(ams_pm_ops, ams_suspend, ams_resume);
> > +
> > +static struct platform_driver ams_driver = {
> > + .probe = ams_probe,
> > + .remove = ams_remove,
> > + .driver = {
> > + .name = "ams",
> > + .pm = &ams_pm_ops,
>
> Spacing here seems a little odd. Just have a single space after pm

Okay.

>
> > + .of_match_table = ams_of_match_table,
> > + },
> > +};
> > +module_platform_driver(ams_driver);
> > +
> > +MODULE_LICENSE("GPL");
> > +MODULE_AUTHOR("Xilinx, Inc.");
> > diff --git a/drivers/iio/adc/xilinx-ams.h
> > b/drivers/iio/adc/xilinx-ams.h new file mode 100644 index
> > 0000000..b9fa262
> > --- /dev/null
> > +++ b/drivers/iio/adc/xilinx-ams.h
>
> I can't immediately see why a lot of this wants to be in a header.
>
> Please move it inline with the C file.

Okay. I will update that in v2.

>
>
> > @@ -0,0 +1,281 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Xilinx AMS driver
> > + *
> > + * Copyright (C) 2017-2018 Xilinx, Inc.
> > + *
> > + * Manish Narani <mnarani@xxxxxxxxxx>
> > + * Rajnikant Bhojani <rajnikant.bhojani@xxxxxxxxxx> */
> > +
> > +#ifndef __XILINX_AMS_H__
> > +#define __XILINX_AMS_H__
> > +
> > +#define AMS_MISC_CTRL 0x000
> > +#define AMS_ISR_0 0x010
> > +#define AMS_ISR_1 0x014
> > +#define AMS_IMR_0 0x018
> > +#define AMS_IMR_1 0x01c
> > +#define AMS_IER_0 0x020
> > +#define AMS_IER_1 0x024
> > +#define AMS_IDR_0 0x028
> > +#define AMS_IDR_1 0x02c
> > +#define AMS_PS_CSTS 0x040
> > +#define AMS_PL_CSTS 0x044
> > +#define AMS_MON_CSTS 0x050
> > +
> > +#define AMS_VCC_PSPLL0 0x060
> > +#define AMS_VCC_PSPLL3 0x06C
> > +#define AMS_VCCINT 0x078
> > +#define AMS_VCCBRAM 0x07C
> > +#define AMS_VCCAUX 0x080
> > +#define AMS_PSDDRPLL 0x084
> > +#define AMS_PSINTFPDDR 0x09C
> > +
> > +#define AMS_VCC_PSPLL0_CH 48
> > +#define AMS_VCC_PSPLL3_CH 51
> > +#define AMS_VCCINT_CH 54
> > +#define AMS_VCCBRAM_CH 55
> > +#define AMS_VCCAUX_CH 56
> > +#define AMS_PSDDRPLL_CH 57
> > +#define AMS_PSINTFPDDR_CH 63
> > +
> > +#define AMS_REG_CONFIG0 0x100
> > +#define AMS_REG_CONFIG1 0x104
> > +#define AMS_REG_CONFIG2 0x108
> > +#define AMS_REG_CONFIG3 0x10C
> > +#define AMS_REG_CONFIG4 0x110
> > +#define AMS_REG_SEQ_CH0 0x120
> > +#define AMS_REG_SEQ_CH1 0x124
> > +#define AMS_REG_SEQ_CH2 0x118
> > +
> > +#define AMS_TEMP 0x000
> > +#define AMS_SUPPLY1 0x004
> > +#define AMS_SUPPLY2 0x008
> > +#define AMS_VP_VN 0x00c
> > +#define AMS_VREFP 0x010
> > +#define AMS_VREFN 0x014
> > +#define AMS_SUPPLY3 0x018
> > +#define AMS_SUPPLY4 0x034
> > +#define AMS_SUPPLY5 0x038
> > +#define AMS_SUPPLY6 0x03c
> > +#define AMS_SUPPLY7 0x200
> > +#define AMS_SUPPLY8 0x204
> > +#define AMS_SUPPLY9 0x208
> > +#define AMS_SUPPLY10 0x20c
> > +#define AMS_VCCAMS 0x210
> > +#define AMS_TEMP_REMOTE 0x214
> > +
> > +#define AMS_REG_VAUX(x) (0x40 + (4*(x)))
> > +#define AMS_REG_VUSER(x) (0x200 + (4*(x)))
> > +
> > +#define AMS_PS_RESET_VALUE 0xFFFFU
> > +#define AMS_PL_RESET_VALUE 0xFFFFU
> > +
> > +#define AMS_CONF0_CHANNEL_NUM_MASK (0x3f << 0)
> > +
> > +#define AMS_CONF1_SEQ_MASK (0xf << 12)
> > +#define AMS_CONF1_SEQ_DEFAULT (0 << 12)
> > +#define AMS_CONF1_SEQ_SINGLE_PASS (1 << 12)
> > +#define AMS_CONF1_SEQ_CONTINUOUS (2 << 12)
> > +#define AMS_CONF1_SEQ_SINGLE_CHANNEL (3 << 12)
> > +
> > +#define AMS_REG_SEQ0_MASK 0xFFFF
> > +#define AMS_REG_SEQ2_MASK 0x3F
> > +#define AMS_REG_SEQ1_MASK 0xFFFF
> > +#define AMS_REG_SEQ2_MASK_SHIFT 16
> > +#define AMS_REG_SEQ1_MASK_SHIFT 22
> > +
> > +#define AMS_REGCFG1_ALARM_MASK 0xF0F
> > +#define AMS_REGCFG3_ALARM_MASK 0x3F
> > +
> > +#define AMS_ALARM_TEMP 0x140
> > +#define AMS_ALARM_SUPPLY1 0x144
> > +#define AMS_ALARM_SUPPLY2 0x148
> > +#define AMS_ALARM_OT 0x14c
> > +
> > +#define AMS_ALARM_SUPPLY3 0x160
> > +#define AMS_ALARM_SUPPLY4 0x164
> > +#define AMS_ALARM_SUPPLY5 0x168
> > +#define AMS_ALARM_SUPPLY6 0x16c
> > +#define AMS_ALARM_SUPPLY7 0x180
> > +#define AMS_ALARM_SUPPLY8 0x184
> > +#define AMS_ALARM_SUPPLY9 0x188
> > +#define AMS_ALARM_SUPPLY10 0x18c
> > +#define AMS_ALARM_VCCAMS 0x190
> > +#define AMS_ALARM_TEMP_REMOTE 0x194
> > +#define AMS_ALARM_THRESHOLD_OFF_10 0x10 #define
> > +AMS_ALARM_THRESHOLD_OFF_20 0x20
> > +
> > +#define AMS_ALARM_THR_DIRECT_MASK 0x01
> > +#define AMS_ALARM_THR_MIN 0x0000
> > +#define AMS_ALARM_THR_MAX 0xffff
> > +
> > +#define AMS_NO_OF_ALARMS 32
> > +#define AMS_PL_ALARM_START 16
> > +#define AMS_ISR0_ALARM_MASK 0xFFFFFFFFU
> > +#define AMS_ISR1_ALARM_MASK 0xE000001FU
> > +#define AMS_ISR1_INTR_MASK_SHIFT 32
> > +#define AMS_ISR0_ALARM_2_TO_0_MASK 0x07
> > +#define AMS_ISR0_ALARM_6_TO_3_MASK 0x78
> > +#define AMS_ISR0_ALARM_12_TO_7_MASK 0x3F
> > +#define AMS_CONF1_ALARM_2_TO_0_SHIFT 1
> > +#define AMS_CONF1_ALARM_6_TO_3_SHIFT 5
> > +#define AMS_CONF3_ALARM_12_TO_7_SHIFT 8
> > +
> > +#define AMS_PS_CSTS_PS_READY 0x08010000U
> > +#define AMS_PL_CSTS_ACCESS_MASK 0x00000001U
> > +
> > +#define AMS_PL_MAX_FIXED_CHANNEL 10
> > +#define AMS_PL_MAX_EXT_CHANNEL 20
> > +
> > +#define AMS_INIT_TIMEOUT 10000
> > +
> > +/*
> > + * Following scale and offset value is derived from
> > + * UG580 (v1.7) December 20, 2016
> > + */
> > +#define AMS_SUPPLY_SCALE_1VOLT 1000
> > +#define AMS_SUPPLY_SCALE_3VOLT 3000
> > +#define AMS_SUPPLY_SCALE_6VOLT 6000
> > +#define AMS_SUPPLY_SCALE_DIV_BIT 16
> > +
> > +#define AMS_TEMP_SCALE 509314
> > +#define AMS_TEMP_SCALE_DIV_BIT 16
> > +#define AMS_TEMP_OFFSET -((280230L << 16) / 509314)
> > +
> > +enum ams_alarm_bit {
> > + AMS_ALARM_BIT_TEMP,
> > + AMS_ALARM_BIT_SUPPLY1,
> > + AMS_ALARM_BIT_SUPPLY2,
> > + AMS_ALARM_BIT_SUPPLY3,
> > + AMS_ALARM_BIT_SUPPLY4,
> > + AMS_ALARM_BIT_SUPPLY5,
> > + AMS_ALARM_BIT_SUPPLY6,
> > + AMS_ALARM_BIT_RESERVED,
> > + AMS_ALARM_BIT_SUPPLY7,
> > + AMS_ALARM_BIT_SUPPLY8,
> > + AMS_ALARM_BIT_SUPPLY9,
> > + AMS_ALARM_BIT_SUPPLY10,
> > + AMS_ALARM_BIT_VCCAMS,
> > + AMS_ALARM_BIT_TEMP_REMOTE
> > +};
> > +
> > +enum ams_seq {
> > + AMS_SEQ_VCC_PSPLL,
> > + AMS_SEQ_VCC_PSBATT,
> > + AMS_SEQ_VCCINT,
> > + AMS_SEQ_VCCBRAM,
> > + AMS_SEQ_VCCAUX,
> > + AMS_SEQ_PSDDRPLL,
> > + AMS_SEQ_INTDDR
> > +};
> > +
> > +enum ams_ps_pl_seq {
> > + AMS_SEQ_CALIB,
> > + AMS_SEQ_RSVD_1,
> > + AMS_SEQ_RSVD_2,
> > + AMS_SEQ_TEST,
> > + AMS_SEQ_RSVD_4,
> > + AMS_SEQ_SUPPLY4,
> > + AMS_SEQ_SUPPLY5,
> > + AMS_SEQ_SUPPLY6,
> > + AMS_SEQ_TEMP,
> > + AMS_SEQ_SUPPLY2,
> > + AMS_SEQ_SUPPLY1,
> > + AMS_SEQ_VP_VN,
> > + AMS_SEQ_VREFP,
> > + AMS_SEQ_VREFN,
> > + AMS_SEQ_SUPPLY3,
> > + AMS_SEQ_CURRENT_MON,
> > + AMS_SEQ_SUPPLY7,
> > + AMS_SEQ_SUPPLY8,
> > + AMS_SEQ_SUPPLY9,
> > + AMS_SEQ_SUPPLY10,
> > + AMS_SEQ_VCCAMS,
> > + AMS_SEQ_TEMP_REMOTE,
> > + AMS_SEQ_MAX
> > +};
> > +
> > +#define AMS_SEQ(x) (AMS_SEQ_MAX + (x))
> > +#define AMS_VAUX_SEQ(x) (AMS_SEQ_MAX + (x))
> > +
> > +#define PS_SEQ_MAX AMS_SEQ_MAX
> > +#define PS_SEQ(x) (x)
> > +#define PL_SEQ(x) (PS_SEQ_MAX + x)
> > +
> > +#define AMS_CHAN_TEMP(_scan_index, _addr, _ext) { \
> > + .type = IIO_TEMP, \
> > + .indexed = 1, \
> > + .address = (_addr), \
> > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
> > + BIT(IIO_CHAN_INFO_SCALE) | \
> > + BIT(IIO_CHAN_INFO_OFFSET), \
> > + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
> > + .event_spec = ams_temp_events, \
> > + .num_event_specs = ARRAY_SIZE(ams_temp_events), \
> > + .scan_index = (_scan_index), \
> > + .scan_type = { \
> > + .sign = 'u', \
> > + .realbits = 12, \
> > + .storagebits = 16, \
> > + .shift = 4, \
> > + .endianness = IIO_CPU, \
> > + }, \
> > + .extend_name = _ext, \
> > +}
> > +
> > +#define AMS_CHAN_VOLTAGE(_scan_index, _addr, _ext, _alarm) { \
> > + .type = IIO_VOLTAGE, \
> > + .indexed = 1, \
> > + .address = (_addr), \
> > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
> > + BIT(IIO_CHAN_INFO_SCALE), \
> > + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
> > + .event_spec = (_alarm) ? ams_voltage_events : NULL, \
> > + .num_event_specs = (_alarm) ? ARRAY_SIZE(ams_voltage_events) : 0, \
> > + .scan_index = (_scan_index), \
> > + .scan_type = { \
> > + .realbits = 10, \
> > + .storagebits = 16, \
> > + .shift = 6, \
> > + .endianness = IIO_CPU, \
> > + }, \
> > + .extend_name = _ext, \
> > +}
> > +
> > +#define AMS_PS_CHAN_TEMP(_scan_index, _addr, _ext) \
> > + AMS_CHAN_TEMP(PS_SEQ(_scan_index), _addr, _ext) #define
> > +AMS_PS_CHAN_VOLTAGE(_scan_index, _addr, _ext) \
> > + AMS_CHAN_VOLTAGE(PS_SEQ(_scan_index), _addr, _ext, true)
> > +
> > +#define AMS_PL_CHAN_TEMP(_scan_index, _addr, _ext) \
> > + AMS_CHAN_TEMP(PL_SEQ(_scan_index), _addr, _ext) #define
> > +AMS_PL_CHAN_VOLTAGE(_scan_index, _addr, _ext, _alarm) \
> > + AMS_CHAN_VOLTAGE(PL_SEQ(_scan_index), _addr, _ext, _alarm)
> #define
> > +AMS_PL_AUX_CHAN_VOLTAGE(_auxno, _ext) \
> > + AMS_CHAN_VOLTAGE(PL_SEQ(AMS_VAUX_SEQ(_auxno)), \
> > + AMS_REG_VAUX(_auxno), _ext, false) #define
> > +AMS_CTRL_CHAN_VOLTAGE(_scan_index, _addr, _ext) \
> > +
> AMS_CHAN_VOLTAGE(PL_SEQ(AMS_VAUX_SEQ(AMS_SEQ(_scan_inde
> x))), \
> > + _addr, _ext, false)
> > +
> > +struct ams {
> > + void __iomem *base;
> > + void __iomem *ps_base;
> > + void __iomem *pl_base;
> > + struct clk *clk;
> > + struct device *dev;
> > +
> > + struct mutex mutex;
> Pleases give clear comments on what these locks are protecting.
> It's certainly curious to see a mutex and a spinlock with such generic names
> right next to each other.

Okay. I will update with the comments in v2.

>
> > + spinlock_t lock;
> > +
> > + unsigned int alarm_mask;
> > + unsigned int masked_alarm;
> > + u64 intr_mask;
> > + int irq;
> As noted above, this is only used next to where it is first set.
> No advantage in having it here.

I will remove this in v2.

>
> > +
> > + struct delayed_work ams_unmask_work; };
> > +
> > +#endif /* __XILINX_AMS_H__ */


Thanks,
Manish Narani