On Tue, 6 Nov 2018 17:41:14 +0100
Philippe Schenker <dev@xxxxxxxxxxxx> wrote:
> From: Stefan Agner <stefan@xxxxxxxx>
>
> This adds an ADC driver for the STMPE device using the industrial
> input/output interface. The driver supports raw reading of values.
> The driver depends on the MFD STMPE driver. If the touchscreen
> block is enabled too, only four of the 8 ADC channels are available.
>
> Signed-off-by: Stefan Agner <stefan@xxxxxxxx>
> Signed-off-by: Max Krummenacher <max.krummenacher@xxxxxxxxxxx>
> Signed-off-by: Philippe Schenker <philippe.schenker@xxxxxxxxxxx>
We are a bit limited in here I think by how it interacts with the mfd
and most of my comments are about the related DT bindings.
A few comments inline.
thanks,
Jonathan
> ---
> drivers/iio/adc/Kconfig | 7 +
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/stmpe-adc.c | 383 +++++++++++++++++++++++++++
> drivers/input/touchscreen/stmpe-ts.c | 11 -
> drivers/mfd/Kconfig | 3 +-
> drivers/mfd/stmpe.c | 27 ++
> include/linux/mfd/stmpe.h | 11 +
> 7 files changed, 431 insertions(+), 12 deletions(-)
> create mode 100644 drivers/iio/adc/stmpe-adc.c
>
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index a52fea8749a9..d2845472b6c2 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -734,6 +734,13 @@ config STM32_DFSDM_ADC
> This driver can also be built as a module. If so, the module
> will be called stm32-dfsdm-adc.
>
> +config STMPE_ADC
> + tristate "STMicroelectronics STMPE ADC driver"
> + depends on (OF || COMPILE_TEST || MFD_STMPE)
> + help
> + Say yes here to build support for ST Microelectronics STMPE
> + built in ADC block (stmpe811).
> +
> config STX104
> tristate "Apex Embedded Systems STX104 driver"
> depends on PC104 && X86
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index a6e6a0b659e2..cba889c30bf9 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -69,6 +69,7 @@ obj-$(CONFIG_STM32_ADC_CORE) += stm32-adc-core.o
> obj-$(CONFIG_STM32_ADC) += stm32-adc.o
> obj-$(CONFIG_STM32_DFSDM_CORE) += stm32-dfsdm-core.o
> obj-$(CONFIG_STM32_DFSDM_ADC) += stm32-dfsdm-adc.o
> +obj-$(CONFIG_STMPE_ADC) += stmpe-adc.o
> obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o
> obj-$(CONFIG_TI_ADC0832) += ti-adc0832.o
> obj-$(CONFIG_TI_ADC084S021) += ti-adc084s021.o
> diff --git a/drivers/iio/adc/stmpe-adc.c b/drivers/iio/adc/stmpe-adc.c
> new file mode 100644
> index 000000000000..891ad838ab3c
> --- /dev/null
> +++ b/drivers/iio/adc/stmpe-adc.c
> @@ -0,0 +1,383 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * STMicroelectronics STMPE811 IIO ADC Driver
> + *
> + * 4 channel, 10/12-bit ADC
> + *
> + * Copyright (C) 2013-2018 Toradex AG <stefan.agner@xxxxxxxxxxx>
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/completion.h>
> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <linux/iio/events.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/mfd/stmpe.h>
> +#include <linux/module.h>
> +#include <linux/of_platform.h>
> +#include <linux/platform_device.h>
> +#include <linux/regulator/consumer.h>
Not seeing any regulators in here. Please do a quick
sanity check on the other headers as well. This is a
long list for a fairly short bit of code!
> +#include <linux/slab.h>
> +
> +#define STMPE_REG_INT_STA 0x0B
> +#define STMPE_REG_ADC_INT_EN 0x0E
> +#define STMPE_REG_ADC_INT_STA 0x0F
> +
> +#define STMPE_REG_ADC_CTRL1 0x20
> +#define STMPE_REG_ADC_CTRL2 0x21
> +#define STMPE_REG_ADC_CAPT 0x22
> +#define STMPE_REG_ADC_DATA_CH(channel) (0x30 + 2 * (channel))
> +
> +#define STMPE_REG_TEMP_CTRL 0x60
> +#define STMPE_START_ONE_TEMP_CONV (0x08 + 0x02 + 0x01)
This is oddly put.. Is it a mask or 3 things we can otherwise
define?
> +#define STMPE_REG_TEMP_DATA 0x61
> +#define STMPE_REG_TEMP_TH 0x63
> +#define STMPE_MAX_ADC_CH 8
> +
> +#define STMPE_ADC_CH(channel) ((1 << (channel)) & 0xff)
> +
> +#define STMPE_ADC_TIMEOUT (msecs_to_jiffies(1000))
Outer brackets don't add anything that I can see.
> +
> +struct stmpe_adc {
personally I always think aligning structure elements is a bad idea as
breaks far too often with later additions. Still I don't care
that much if you really want to do this...
> + struct stmpe *stmpe;
> + struct clk *clk;
> + struct device *dev;
> +
> + struct iio_chan_spec stmpe_adc_iio_channels[STMPE_MAX_ADC_CH];
> +
> + struct completion completion;
> +
> + u8 channel;
> + u32 value;
> + u8 sample_time;
> + u8 mod_12b;
> + u8 ref_sel;
> + u8 adc_freq;
> + u32 norequest_mask;
> +};
> +
> +static int stmpe_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val,
> + int *val2,
> + long mask)
> +{
> + struct stmpe_adc *info = iio_priv(indio_dev);
> + long ret;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + case IIO_CHAN_INFO_PROCESSED:
> +
> + mutex_lock(&indio_dev->mlock);
> +
> + info->channel = (u8)chan->channel;
> +
> + switch (chan->type) {
> + case IIO_VOLTAGE:
> + if (info->channel > 7)
lock held.
> + return -ENOENT;
> +
> + stmpe_reg_write(info->stmpe, STMPE_REG_ADC_INT_EN,
> + STMPE_ADC_CH(info->channel));
> +
> + stmpe_reg_write(info->stmpe, STMPE_REG_ADC_CAPT,
> + STMPE_ADC_CH(info->channel));
> +
> + *val = info->value;
> + break;
> +
> + case IIO_TEMP:
> + if (info->channel != 8)
lock held...
> + return -ENOENT;
> +
> + stmpe_reg_write(info->stmpe, STMPE_REG_TEMP_CTRL,
> + STMPE_START_ONE_TEMP_CONV);
> + break;
> + default:
> + mutex_unlock(&indio_dev->mlock);
> + return -EINVAL;
> + }
> +
> + ret = wait_for_completion_interruptible_timeout
> + (&info->completion, STMPE_ADC_TIMEOUT);
> +
> + if (ret <= 0) {
> + mutex_unlock(&indio_dev->mlock);
> + if (ret == 0)
> + return -ETIMEDOUT;
> + else
> + return ret;
> + }
> +
> +
> + switch (chan->type) {
> + case IIO_VOLTAGE:
> + *val = info->value;
> + break;
> +
> + case IIO_TEMP:
> + /*
> + * absolute temp = +V3.3 * value /7.51 [K]
> + * scale to [milli °C]
> + */
> + *val = ((449960l * info->value) / 1024l) - 273150;
> + break;
> + default:
> + break;
> + }
> +
> + mutex_unlock(&indio_dev->mlock);
> + return IIO_VAL_INT;
> +
> + case IIO_CHAN_INFO_SCALE:
> + *val = 3300;
> + *val2 = info->mod_12b ? 12 : 10;
> + return IIO_VAL_FRACTIONAL_LOG2;
> +
> + default:
> + break;
> + }
> +
> + return -EINVAL;
> +}
> +
> +static irqreturn_t stmpe_adc_isr(int irq, void *dev_id)
> +{
> + struct stmpe_adc *info = (struct stmpe_adc *)dev_id;
> + u8 data[2];
> +
> + if (info->channel > 8)
> + return IRQ_NONE;
> +
> + if (info->channel < 8) {
> + int int_sta;
> +
> + int_sta = stmpe_reg_read(info->stmpe, STMPE_REG_ADC_INT_STA);
> +
> + /* Is the interrupt relevant */
> + if (!(int_sta & STMPE_ADC_CH(info->channel)))
> + return IRQ_NONE;
> +
> + /* Read value */
> + stmpe_block_read(info->stmpe,
> + STMPE_REG_ADC_DATA_CH(info->channel), 2, data);
> +
> + stmpe_reg_write(info->stmpe, STMPE_REG_ADC_INT_STA, int_sta);
> + } else if (info->channel == 8) {
That 8 is pretty magic, perhaps a define given it keeps being used?
> + /* Read value */
> + stmpe_block_read(info->stmpe, STMPE_REG_TEMP_DATA, 2, data);
> + }
> +
> + info->value = ((u32)data[0] << 8) + data[1];
> + complete(&info->completion);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static const struct iio_info stmpe_adc_iio_info = {
> + .read_raw = &stmpe_read_raw,
> +};
> +
> +static void stmpe_adc_voltage_chan(struct iio_chan_spec *ics, int chan)
> +{
> + ics->type = IIO_VOLTAGE;
> + ics->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
> + ics->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE);
> + ics->indexed = 1;
> + ics->channel = chan;
> +}
> +
> +static void stmpe_adc_temp_chan(struct iio_chan_spec *ics, int chan)
> +{
> + ics->type = IIO_TEMP;
> + ics->info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED);
> + ics->indexed = 1;
> + ics->channel = chan;
> +}
> +
> +static int stmpe_adc_init_hw(struct stmpe_adc *adc)
> +{
> + int ret;
> + u8 adc_ctrl1, adc_ctrl1_mask;
> + struct stmpe *stmpe = adc->stmpe;
> + struct device *dev = adc->dev;
> +
> + ret = stmpe_enable(stmpe, STMPE_BLOCK_ADC);
> + if (ret) {
> + dev_err(dev, "Could not enable clock for ADC\n");
> + goto err_adc;
> + }
> +
> + adc_ctrl1 = SAMPLE_TIME(adc->sample_time) | MOD_12B(adc->mod_12b) |
> + REF_SEL(adc->ref_sel);
> + adc_ctrl1_mask = SAMPLE_TIME(0xff) | MOD_12B(0xff) | REF_SEL(0xff);
> +
> + ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL1,
> + adc_ctrl1_mask, adc_ctrl1);
> + if (ret) {
> + dev_err(dev, "Could not setup ADC\n");
> + goto err_adc;
> + }
> +
> + ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL2,
> + ADC_FREQ(0xff), ADC_FREQ(adc->adc_freq));
> + if (ret) {
> + dev_err(dev, "Could not setup ADC\n");
> + goto err_adc;
> + }
> +
> + /* use temp irq for each conversion completion */
> + stmpe_reg_write(stmpe, STMPE_REG_TEMP_TH, 0);
> + stmpe_reg_write(stmpe, STMPE_REG_TEMP_TH + 1, 0);
> +
> + return 0;
> +err_adc:
> + stmpe_disable(stmpe, STMPE_BLOCK_ADC);
> +
> + return ret;
> +}
> +
> +static void stmpe_adc_get_platform_info(struct platform_device *pdev,
> + struct stmpe_adc *adc)
> +{
> + struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent);
> + struct device_node *np = pdev->dev.of_node;
> + u32 val;
> +
> + adc->stmpe = stmpe;
> +
> + if (!np) {
> + dev_err(&pdev->dev, "no device tree node found\n");
> + return;
> + }
> +
> + if (!of_property_read_u32(np, "st,sample-time", &val))
> + adc->sample_time = val;
> + if (!of_property_read_u32(np, "st,mod-12b", &val))
> + adc->mod_12b = val;
> + if (!of_property_read_u32(np, "st,ref-sel", &val))
> + adc->ref_sel = val;
> + if (!of_property_read_u32(np, "st,adc-freq", &val))
> + adc->adc_freq = val;
> + if (!of_property_read_u32(np, "st,norequest-mask", &val))
> + adc->norequest_mask = val;
I commented on these in the dt-binding patch, so I won't mention
them any more here.
> +}
> +
> +static int stmpe_adc_probe(struct platform_device *pdev)
> +{
> + struct iio_dev *indio_dev = NULL;
> + struct stmpe_adc *info = NULL;
> + int irq_temp, irq_adc;
> + int num_chan = 0;
> + int i = 0;
> + int ret;
> +
> + irq_adc = platform_get_irq_byname(pdev, "STMPE_ADC");
> + if (irq_adc < 0)
> + return irq_adc;
> +
> + indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(struct stmpe_adc));
> + if (!indio_dev) {
> + dev_err(&pdev->dev, "failed allocating iio device\n");
> + return -ENOMEM;
> + }
> +
> + info = iio_priv(indio_dev);
> +
> + init_completion(&info->completion);
> + ret = devm_request_threaded_irq(&pdev->dev, irq_adc, NULL,
> + stmpe_adc_isr, IRQF_ONESHOT,
> + "stmpe-adc", info);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "failed requesting irq, irq = %d\n",
> + irq_adc);
> + return ret;
> + }
> +
> + irq_temp = platform_get_irq_byname(pdev, "STMPE_TEMP_SENS");
> + if (irq_temp >= 0) {
> + ret = devm_request_threaded_irq(&pdev->dev, irq_temp, NULL,
> + stmpe_adc_isr, IRQF_ONESHOT,
> + "stmpe-adc", info);
> + if (ret < 0)
> + dev_warn(&pdev->dev, "failed requesting irq for"
> + " temp sensor, irq = %d\n", irq_temp);
> + }
I'd like a comment here that perhaps says what the result of not having an
irq for the temperature sensor is?
> +
> + platform_set_drvdata(pdev, indio_dev);
> +
> + indio_dev->name = dev_name(&pdev->dev);
> + indio_dev->dev.parent = &pdev->dev;
> + indio_dev->info = &stmpe_adc_iio_info;
> + indio_dev->modes = INDIO_DIRECT_MODE;
> +
> + stmpe_adc_get_platform_info(pdev, info);
> +
> + for_each_clear_bit(i, (unsigned long *) &info->norequest_mask,
> + STMPE_MAX_ADC_CH) {
> + stmpe_adc_voltage_chan(&info->stmpe_adc_iio_channels[num_chan], i);
> + num_chan++;
> + }
> + stmpe_adc_temp_chan(&info->stmpe_adc_iio_channels[num_chan], i);
> + num_chan++;
> + indio_dev->channels = info->stmpe_adc_iio_channels;
> + indio_dev->num_channels = num_chan;
> +
> + ret = stmpe_adc_init_hw(info);
> + if (ret)
> + return ret;
> +
> + ret = iio_device_register(indio_dev);
> + if (ret)
> + return ret;
one blank line is plenty.
> +
> +
> + dev_info(&pdev->dev, "Initialized\n");
This is just noise in the log. There are lots of ways of finding
out if this came up if you actually want to so no need for the print here.
> +
> + return 0;
> +}
> +
> +static int stmpe_adc_remove(struct platform_device *pdev)
> +{
> + struct iio_dev *indio_dev = platform_get_drvdata(pdev);
> + struct stmpe_adc *info = iio_priv(indio_dev);
> +
> + iio_device_unregister(indio_dev);
> + stmpe_disable(info->stmpe, STMPE_BLOCK_ADC);
> +
> + return 0;
> +}
> +
> +static int __maybe_unused stmpe_adc_resume(struct device *dev)
> +{
> + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> + struct stmpe_adc *info = iio_priv(indio_dev);
> +
> + stmpe_adc_init_hw(info);
> +
> + return 0;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(stmpe_adc_pm_ops, NULL, stmpe_adc_resume);
> +
> +static struct platform_driver stmpe_adc_driver = {
> + .probe = stmpe_adc_probe,
> + .remove = stmpe_adc_remove,
> + .driver = {
> + .name = "stmpe-adc",
> + .pm = &stmpe_adc_pm_ops,
> + },
> +};
> +
> +module_platform_driver(stmpe_adc_driver);
> +
> +MODULE_AUTHOR("Stefan Agner <stefan.agner@xxxxxxxxxxx>");
> +MODULE_DESCRIPTION("STMPEXXX ADC driver");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:stmpe-adc");
> diff --git a/drivers/input/touchscreen/stmpe-ts.c b/drivers/input/touchscreen/stmpe-ts.c
> index 2a78e27b4495..05674e0e233f 100644
> --- a/drivers/input/touchscreen/stmpe-ts.c
> +++ b/drivers/input/touchscreen/stmpe-ts.c
> @@ -49,17 +49,6 @@
>
> #define STMPE_IRQ_TOUCH_DET 0
>
> -#define SAMPLE_TIME(x) ((x & 0xf) << 4)
> -#define MOD_12B(x) ((x & 0x1) << 3)
> -#define REF_SEL(x) ((x & 0x1) << 1)
> -#define ADC_FREQ(x) (x & 0x3)
> -#define AVE_CTRL(x) ((x & 0x3) << 6)
> -#define DET_DELAY(x) ((x & 0x7) << 3)
> -#define SETTLING(x) (x & 0x7)
> -#define FRACTION_Z(x) (x & 0x7)
> -#define I_DRIVE(x) (x & 0x1)
> -#define OP_MODE(x) ((x & 0x7) << 1)
> -
Given the need for prefixes in the header (see below) I would
do this move as a precursor patch including renames in the
touchscreen driver...
> #define STMPE_TS_NAME "stmpe-ts"
> #define XY_MASK 0xfff
>
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index 8c5dfdce4326..bba159e8eaa4 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -1204,7 +1204,7 @@ config MFD_STMPE
>
> Currently supported devices are:
>
> - STMPE811: GPIO, Touchscreen
> + STMPE811: GPIO, Touchscreen, ADC
> STMPE1601: GPIO, Keypad
> STMPE1801: GPIO, Keypad
> STMPE2401: GPIO, Keypad
> @@ -1217,6 +1217,7 @@ config MFD_STMPE
> GPIO: stmpe-gpio
> Keypad: stmpe-keypad
> Touchscreen: stmpe-ts
> + ADC: stmpe-adc
>
> menu "STMicroelectronics STMPE Interface Drivers"
> depends on MFD_STMPE
> diff --git a/drivers/mfd/stmpe.c b/drivers/mfd/stmpe.c
> index 566caca4efd8..00b98f75f7dd 100644
> --- a/drivers/mfd/stmpe.c
> +++ b/drivers/mfd/stmpe.c
> @@ -463,6 +463,28 @@ static const struct mfd_cell stmpe_ts_cell = {
> .num_resources = ARRAY_SIZE(stmpe_ts_resources),
> };
>
> +/*
> + * ADC (STMPE811)
> + */
> +
> +static struct resource stmpe_adc_resources[] = {
> + {
> + .name = "STMPE_TEMP_SENS",
> + .flags = IORESOURCE_IRQ,
> + },
> + {
> + .name = "STMPE_ADC",
> + .flags = IORESOURCE_IRQ,
> + },
> +};
> +
> +static const struct mfd_cell stmpe_adc_cell = {
> + .name = "stmpe-adc",
> + .of_compatible = "st,stmpe-adc",
> + .resources = stmpe_adc_resources,
> + .num_resources = ARRAY_SIZE(stmpe_adc_resources),
> +};
> +
> /*
> * STMPE811 or STMPE610
> */
> @@ -497,6 +519,11 @@ static struct stmpe_variant_block stmpe811_blocks[] = {
> .irq = STMPE811_IRQ_TOUCH_DET,
> .block = STMPE_BLOCK_TOUCHSCREEN,
> },
> + {
> + .cell = &stmpe_adc_cell,
> + .irq = STMPE811_IRQ_TEMP_SENS,
> + .block = STMPE_BLOCK_ADC,
> + },
> };
>
> static int stmpe811_enable(struct stmpe *stmpe, unsigned int blocks,
> diff --git a/include/linux/mfd/stmpe.h b/include/linux/mfd/stmpe.h
> index 4a827af17e59..90700013f56d 100644
> --- a/include/linux/mfd/stmpe.h
> +++ b/include/linux/mfd/stmpe.h
> @@ -10,6 +10,17 @@
>
> #include <linux/mutex.h>
>
> +#define SAMPLE_TIME(x) ((x & 0xf) << 4)
> +#define MOD_12B(x) ((x & 0x1) << 3)
> +#define REF_SEL(x) ((x & 0x1) << 1)
> +#define ADC_FREQ(x) (x & 0x3)
> +#define AVE_CTRL(x) ((x & 0x3) << 6)
> +#define DET_DELAY(x) ((x & 0x7) << 3)
> +#define SETTLING(x) (x & 0x7)
> +#define FRACTION_Z(x) (x & 0x7)
> +#define I_DRIVE(x) (x & 0x1)
> +#define OP_MODE(x) ((x & 0x7) << 1)
I assumed that these were in keeping with naming in this file but
they aren't. Should have a prefix to avoid potential name clashes
in the future.
STMPE_SAMPlE_TIME etc would make sense.
> +
> struct device;
> struct regulator;
>
