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Date: Tue, 2 Apr 2019 14:30:27 +0900
From: Kanematsu, Shinji/兼松 伸次
<kanematsu.shinji@...ionext.com>
To: Jonathan Cameron <jic23@...nel.org>
Cc: kanematsu.shinji@...ionext.com, knaack.h@....de, lars@...afoo.de,
pmeerw@...erw.net, linux-iio@...r.kernel.org,
linux-kernel@...r.kernel.org, masami.hiramatsu@...aro.org,
jaswinder.singh@...aro.org, orito.takao@...ionext.com,
sugaya.taichi@...ionext.com, kasai.kazuhiro@...ionext.com
Subject: Re: [PATCH 2/2] iio: counter: Add support for Milbeaut Updown Counter
Hi Jonathan,
Thank you for your review.
On 2019/03/31 3:43, Jonathan Cameron wrote:
> On Tue, 26 Mar 2019 15:33:32 +0900
> Shinji Kanematsu <kanematsu.shinji@...ionext.com> wrote:
>
>> Add support for Milbeaut Updown Counter, that can be used as counter
>> or quadrature encoder.
>>
>> Signed-off-by: Shinji Kanematsu <kanematsu.shinji@...ionext.com>
> A few minor comments inline. The counter subsystem will provide a cleaner
> way of describing this. Please look to that for v2.
>
> Hopefully William will give some feedback as well.
>
OK, I understand.
> Jonathan
>> ---
>> drivers/iio/counter/Kconfig | 12 +
>> drivers/iio/counter/Makefile | 1 +
>> drivers/iio/counter/milbeaut-updown.h | 38 +++
>> drivers/iio/counter/milbeaut-updown_cnt.c | 385 ++++++++++++++++++++++++++++++
>> 4 files changed, 436 insertions(+)
>> create mode 100644 drivers/iio/counter/milbeaut-updown.h
>> create mode 100644 drivers/iio/counter/milbeaut-updown_cnt.c
>>
>> diff --git a/drivers/iio/counter/Kconfig b/drivers/iio/counter/Kconfig
>> index bf1e559..a665f61 100644
>> --- a/drivers/iio/counter/Kconfig
>> +++ b/drivers/iio/counter/Kconfig
>> @@ -31,4 +31,16 @@ config STM32_LPTIMER_CNT
>>
>> To compile this driver as a module, choose M here: the
>> module will be called stm32-lptimer-cnt.
>> +
>> +config MILBEAUT_UPDOWN_CNT
>> + tristate "Milbeaut Updown Counter driver"
>> + depends on OF
>> + depends on ARCH_MILBEAUT || COMPILE_TEST
>> + help
>> + Select this option to enable Milbeaut Updown Counter quadrature encoder
>> + and counter driver.
>> +
>> + To compile this driver as a module, choose M here: the
>> + module will be called milbeaut-updown-cnt.
>> +
>> endmenu
>> diff --git a/drivers/iio/counter/Makefile b/drivers/iio/counter/Makefile
>> index 1b9a896..0cb708b 100644
>> --- a/drivers/iio/counter/Makefile
>> +++ b/drivers/iio/counter/Makefile
>> @@ -6,3 +6,4 @@
>>
>> obj-$(CONFIG_104_QUAD_8) += 104-quad-8.o
>> obj-$(CONFIG_STM32_LPTIMER_CNT) += stm32-lptimer-cnt.o
>> +obj-$(CONFIG_MILBEAUT_UPDOWN_CNT) += milbeaut-updown_cnt.o
>> diff --git a/drivers/iio/counter/milbeaut-updown.h b/drivers/iio/counter/milbeaut-updown.h
>> new file mode 100644
>> index 0000000..9a038ad
>> --- /dev/null
>> +++ b/drivers/iio/counter/milbeaut-updown.h
>> @@ -0,0 +1,38 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +/*
>> + * Milbeaut Updown parent driver
>> + * Copyright (C) 2019 Socionext Inc.
>> + */
>> +
>> +#ifndef _LINUX_MILBEAUT_UPDOWN_H_
>> +#define _LINUX_MILBEAUT_UPDOWN_H_
>> +
>> +#define MLB_UPDOWN_UDCR 0x0 /* Updown Count Reg */
>> +#define MLB_UPDOWN_RCR 0x4 /* Reload Compare Reg */
>> +#define MLB_UPDOWN_CSR 0xC /* Counter Status Reg */
>> +#define MLB_UPDOWN_CCR 0x14 /* Counter Control Reg */
>> +
>> +/* MLB_UPDOWN_CSR - bit fields */
>> +#define MLB_UPDOWN_CSTR BIT(7)
>> +#define MLB_UPDOWN_UDIE BIT(5)
>> +#define MLB_UPDOWN_CMPF BIT(4)
>> +#define MLB_UPDOWN_OVFF BIT(3)
>> +#define MLB_UPDOWN_UDFF BIT(2)
>> +
>> +/* MLB_UPDOWN_CCR - bit fields */
>> +#define MLB_UPDOWN_FIXED BIT(15)
>> +#define MLB_UPDOWN_CMS GENMASK(11, 10)
>> +#define MLB_UPDOWN_CES GENMASK(9, 8)
>> +#define MLB_UPDOWN_CTUT BIT(6)
>> +#define MLB_UPDOWN_RLDE BIT(4)
>> +
>> +/* MLB_UPDOWN max count value */
>> +#define MLB_UPDOWN_MAX_COUNT 0xFFFF
>> +
>> +/* MLB_UPDOWN rising edge detection */
>> +#define MLB_UPDOWN_RISING_EDGE BIT(9)
>> +
>> +/* MLB_UPDOWN mode */
>> +#define MLB_UPDOWN_MODE 1
>> +
>> +#endif
>> diff --git a/drivers/iio/counter/milbeaut-updown_cnt.c b/drivers/iio/counter/milbeaut-updown_cnt.c
>> new file mode 100644
>> index 0000000..a58709a
>> --- /dev/null
>> +++ b/drivers/iio/counter/milbeaut-updown_cnt.c
>> @@ -0,0 +1,385 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Milbeaut Updown counter driver
>> + *
>> + * Copyright (C) 2019 Socionext Inc.
> I'm fussy about pointless lines. The one below doesn't add anything ;)
That's right, correct it.
>> + *
>> + */
>> +
>> +#include <linux/bitfield.h>
>> +#include <linux/clk.h>
>> +#include <linux/iio/events.h>
>> +#include <linux/iio/iio.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/module.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/regmap.h>
>> +
>> +#include "milbeaut-updown.h"
>> +
>> +#define MILBEAUT_UPDOWN_IRQ_NAME "milbeaut_updown_event"
>> +#define MILBEAUT_UPDOWN_MAX_REGISTER 0x1f
>> +
>> +static const struct regmap_config milbeaut_updown_regmap_cfg = {
>> + .reg_bits = 32,
>> + .val_bits = 32,
>> + .reg_stride = sizeof(u32),
>> + .max_register = MILBEAUT_UPDOWN_MAX_REGISTER,
>> +};
>> +struct milbeaut_updown_cnt {
>> + struct device *dev;
>> + struct regmap *regmap;
>> + struct clk *clk;
>> + u32 preset;
>> + u32 polarity;
>> + u32 quadrature_mode;
>> +};
>> +
>> +static int milbeaut_updown_is_enabled(struct milbeaut_updown_cnt *priv)
>> +{
>> + u32 val;
>> + int ret;
>> +
>> + ret = regmap_read(priv->regmap, MLB_UPDOWN_CSR, &val);
>> + if (ret)
>> + return ret;
>> +
>> + return FIELD_GET(MLB_UPDOWN_CSTR, val);
>> +}
>> +
>> +static int milbeaut_updown_setup(struct milbeaut_updown_cnt *priv,
>> + int val)
>> +{
>> + int ret;
>> +
>> + if (val) {
>> + ret = regmap_update_bits(priv->regmap, MLB_UPDOWN_CCR,
>> + MLB_UPDOWN_CMS | MLB_UPDOWN_RLDE,
>> + FIELD_PREP(MLB_UPDOWN_CMS, priv->quadrature_mode) |
>> + MLB_UPDOWN_RLDE);
>> + if (ret)
>> + return ret;
>> +
>> + if (priv->quadrature_mode == MLB_UPDOWN_MODE) {
>> + ret = regmap_update_bits(priv->regmap, MLB_UPDOWN_CCR,
>> + MLB_UPDOWN_CES, MLB_UPDOWN_RISING_EDGE);
>> + if (ret)
>> + return ret;
>> + }
>> +
>> + ret = regmap_write(priv->regmap, MLB_UPDOWN_RCR, priv->preset);
>> + if (ret)
>> + return ret;
>> +
>> + /* interrupt */
>> + ret = regmap_update_bits(priv->regmap, MLB_UPDOWN_CSR,
>> + MLB_UPDOWN_UDIE, MLB_UPDOWN_UDIE);
>> + if (ret)
>> + return ret;
>> +
>> + ret = regmap_update_bits(priv->regmap, MLB_UPDOWN_CCR,
>> + MLB_UPDOWN_CTUT | MLB_UPDOWN_FIXED,
>> + MLB_UPDOWN_CTUT | MLB_UPDOWN_FIXED);
>> + if (ret)
>> + return ret;
>> +
>> + val = MLB_UPDOWN_CSTR;
>> + }
>> +
>> + return regmap_update_bits(priv->regmap, MLB_UPDOWN_CSR,
>> + MLB_UPDOWN_CSTR, val);
>> +}
>> +
>> +static int milbeaut_updown_write_raw(struct iio_dev *indio_dev,
>> + struct iio_chan_spec const *chan,
>> + int val, int val2, long mask)
>> +{
>> + struct milbeaut_updown_cnt *priv = iio_priv(indio_dev);
>> + int ret;
>> +
>> + switch (mask) {
>> + case IIO_CHAN_INFO_ENABLE:
>> + if (val < 0 || val > 1)
>> + return -EINVAL;
>> +
>> + ret = milbeaut_updown_is_enabled(priv);
>> + if (val && ret)
>> + return -EBUSY;
>> +
>> + ret = milbeaut_updown_setup(priv, val);
>> +
>> + break;
>> +
>> + default:
>> + return -EINVAL;
>> + }
>> +
>> + return ret;
>> +}
>> +
>> +static int milbeaut_updown_read_raw(struct iio_dev *indio_dev,
>> + struct iio_chan_spec const *chan,
>> + int *val, int *val2, long mask)
>> +{
>> + struct milbeaut_updown_cnt *priv = iio_priv(indio_dev);
>> + u32 dat;
>> + int ret;
>> +
>> + switch (mask) {
>> + case IIO_CHAN_INFO_RAW:
>> + ret = regmap_read(priv->regmap, MLB_UPDOWN_UDCR, &dat);
>> + if (ret)
>> + return ret;
>> + *val = dat;
>> + return IIO_VAL_INT;
>> +
>> + case IIO_CHAN_INFO_ENABLE:
>> + ret = milbeaut_updown_is_enabled(priv);
>> + if (ret < 0)
>> + return ret;
>> + *val = ret;
>> + return IIO_VAL_INT;
>> +
>> + default:
>> + return -EINVAL;
>> + }
>> +}
>> +
>> +static const struct iio_info milbeaut_updown_cnt_iio_info = {
>> + .read_raw = milbeaut_updown_read_raw,
>> + .write_raw = milbeaut_updown_write_raw,
>> +};
>> +
>> +static const char *const milbeaut_updown_quadrature_modes[] = {
>> + "non-quadrature",
>> + "quadrature",
>> +};
>> +
>> +static int milbeaut_updown_get_quadrature_mode(struct iio_dev *indio_dev,
>> + const struct iio_chan_spec *chan)
>> +{
>> + struct milbeaut_updown_cnt *priv = iio_priv(indio_dev);
>> +
>> + return priv->quadrature_mode;
>> +}
>> +
>> +static int milbeaut_updown_set_quadrature_mode(struct iio_dev *indio_dev,
>> + const struct iio_chan_spec *chan,
>> + unsigned int type)
>> +{
>> + struct milbeaut_updown_cnt *priv = iio_priv(indio_dev);
>> +
>> + if (milbeaut_updown_is_enabled(priv))
>> + return -EBUSY;
>> +
>> + priv->quadrature_mode = type;
>> +
>> + return 0;
>> +}
>> +
>> +static const struct iio_enum milbeaut_updown_quadrature_mode_en = {
>> + .items = milbeaut_updown_quadrature_modes,
>> + .num_items = ARRAY_SIZE(milbeaut_updown_quadrature_modes),
>> + .get = milbeaut_updown_get_quadrature_mode,
>> + .set = milbeaut_updown_set_quadrature_mode,
>> +};
>> +
>> +static const char * const milbeaut_updown_cnt_polarity[] = {
>> + "rising-edge", "falling-edge", "both-edges",
>> +};
>> +
>> +static int milbeaut_updown_cnt_get_polarity(struct iio_dev *indio_dev,
>> + const struct iio_chan_spec *chan)
>> +{
>> + struct milbeaut_updown_cnt *priv = iio_priv(indio_dev);
>> +
>> + return priv->polarity;
>> +}
>> +
>> +static int milbeaut_updown_cnt_set_polarity(struct iio_dev *indio_dev,
>> + const struct iio_chan_spec *chan,
>> + unsigned int type)
>> +{
>> + struct milbeaut_updown_cnt *priv = iio_priv(indio_dev);
>> +
>> + if (milbeaut_updown_is_enabled(priv))
>> + return -EBUSY;
>> +
>> + priv->polarity = type;
>> +
>> + return 0;
>> +}
>> +
>> +static const struct iio_enum milbeaut_updown_cnt_polarity_en = {
>> + .items = milbeaut_updown_cnt_polarity,
>> + .num_items = ARRAY_SIZE(milbeaut_updown_cnt_polarity),
>> + .get = milbeaut_updown_cnt_get_polarity,
>> + .set = milbeaut_updown_cnt_set_polarity,
>> +};
>> +
>> +static ssize_t milbeaut_updown_cnt_get_preset(struct iio_dev *indio_dev,
>> + uintptr_t private,
>> + const struct iio_chan_spec *chan,
>> + char *buf)
>> +{
>> + struct milbeaut_updown_cnt *priv = iio_priv(indio_dev);
>> +
>> + return snprintf(buf, PAGE_SIZE, "%u\n", priv->preset);
>> +}
>> +
>> +static ssize_t milbeaut_updown_cnt_set_preset(struct iio_dev *indio_dev,
>> + uintptr_t private,
>> + const struct iio_chan_spec *chan,
>> + const char *buf, size_t len)
>> +{
>> + struct milbeaut_updown_cnt *priv = iio_priv(indio_dev);
>> + u32 check_preset;
>> + int ret;
>> +
>> + if (milbeaut_updown_is_enabled(priv))
>> + return -EBUSY;
>> +
>> + ret = kstrtouint(buf, 0, &check_preset);
>> + if (ret)
>> + return ret;
>> +
>> + if (check_preset > MLB_UPDOWN_MAX_COUNT)
>> + return -EINVAL;
>> +
>> + ret = kstrtouint(buf, 0, &priv->preset);
> This structure is a little unusual.
> priv->preset = check_preset and that can't result
> in an error.
>
It is strange that I did not notice myself.
>> + if (ret)
>> + return ret;
>> +
>> + return len;
>> +}
>> +
>> +static const struct iio_chan_spec_ext_info milbeaut_updown_cnt_ext_info[] = {
>> + {
>> + .name = "preset",
>> + .shared = IIO_SEPARATE,
>> + .read = milbeaut_updown_cnt_get_preset,
>> + .write = milbeaut_updown_cnt_set_preset,
>> + },
>> + IIO_ENUM("polarity", IIO_SEPARATE, &milbeaut_updown_cnt_polarity_en),
>> + IIO_ENUM_AVAILABLE("polarity", &milbeaut_updown_cnt_polarity_en),
>> + {}
>> +};
>> +
>> +static const struct iio_event_spec milbeaut_updown_cnt_event = {
>> + .type = IIO_EV_TYPE_ROC,
>> + .dir = IIO_EV_DIR_RISING,
>> + .mask_separate = BIT(IIO_EV_INFO_ENABLE),
>> + .mask_shared_by_type = BIT(IIO_EV_INFO_VALUE),
>> +};
>> +
>> +static const struct iio_chan_spec milbeaut_updown_cnt_channels = {
>> + .type = IIO_COUNT,
>> + .channel = 0,
>> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
>> + BIT(IIO_CHAN_INFO_ENABLE) |
>> + BIT(IIO_CHAN_INFO_SCALE),
>> + .ext_info = milbeaut_updown_cnt_ext_info,
>> + .indexed = 1,
>> + .event_spec = &milbeaut_updown_cnt_event,
>> + .num_event_specs = 1,
>> +};
>> +
>> +static irqreturn_t milbeaut_updown_event_handler(int irq, void *private)
>> +{
>> + struct iio_dev *indio_dev = private;
>> + struct milbeaut_updown_cnt *priv;
>> + int ret;
>> +
>> + priv = iio_priv(indio_dev);
>> +
>> + ret = regmap_update_bits(priv->regmap, MLB_UPDOWN_CSR,
>> + MLB_UPDOWN_CMPF | MLB_UPDOWN_OVFF | MLB_UPDOWN_UDFF,
>> + 0);
>> + WARN_ON_ONCE(ret < 0);
>> +
>> + iio_push_event(indio_dev,
>> + IIO_MOD_EVENT_CODE(IIO_INCLI, 0, 1,
>> + IIO_EV_TYPE_ROC, IIO_EV_DIR_RISING),
>> + iio_get_time_ns(indio_dev));
>> +
>> + return IRQ_HANDLED;
>> +}
>> +
>> +static int milbeaut_updown_cnt_probe(struct platform_device *pdev)
>> +{
>> + struct milbeaut_updown_cnt *priv;
>> + struct iio_dev *indio_dev;
>> + struct resource *res;
>> + void __iomem *mmio;
>> + int ret;
>> + int irq;
>> +
>> + indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*priv));
>> + if (!indio_dev)
>> + return -ENOMEM;
>> +
>> + priv = iio_priv(indio_dev);
>> + priv->dev = &pdev->dev;
>> +
>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> + mmio = devm_ioremap_resource(&pdev->dev, res);
>> + if (IS_ERR(mmio))
>> + return PTR_ERR(mmio);
>> +
>> + priv->regmap = devm_regmap_init_mmio_clk(&pdev->dev, "mux", mmio,
>> + &milbeaut_updown_regmap_cfg);
>> + if (IS_ERR(priv->regmap))
>> + return PTR_ERR(priv->regmap);
>> +
>> + priv->clk = devm_clk_get(&pdev->dev, NULL);
>> + if (IS_ERR(priv->clk))
>> + return PTR_ERR(priv->clk);
>> +
>> + priv->preset = MLB_UPDOWN_MAX_COUNT;
>> + ret = of_property_read_u32(priv->dev->of_node,
>> + "cms_type", &priv->quadrature_mode);
>> + if (ret)
>> + return -ENODEV;
>> +
>> + indio_dev->name = dev_name(&pdev->dev);
>> + indio_dev->dev.parent = &pdev->dev;
>> + indio_dev->dev.of_node = pdev->dev.of_node;
> Why set this. I don't think anything uses it?
>
That's right, delete it.
>> + indio_dev->info = &milbeaut_updown_cnt_iio_info;
>> + indio_dev->channels = &milbeaut_updown_cnt_channels;
>> + indio_dev->num_channels = 1;
>> +
>> + /* setting request irq */
> The comment doesn't add anything not apparent directly from the code.
OK, delete it.
>> + irq = platform_get_irq(pdev, 0);
>> + ret = devm_request_threaded_irq(&pdev->dev, irq,
>> + NULL, milbeaut_updown_event_handler,
>> + IRQF_TRIGGER_RISING | IRQF_ONESHOT,
>> + MILBEAUT_UPDOWN_IRQ_NAME, indio_dev);
>> + if (ret < 0) {
>> + pr_err("%s request irq failed\n", __func__);
>> + return ret;
>> + }
>> +
>> + platform_set_drvdata(pdev, priv);
> Why? I'm not seeing calls to platform_get_drvdata.
That's right, delete it.
>> +
>> + return devm_iio_device_register(&pdev->dev, indio_dev);
>> +}
>> +
>> +static const struct of_device_id milbeaut_updown_cnt_of_match[] = {
>> + { .compatible = "socionext,milbeaut-updown-counter", },
>> + {},
>> +};
>> +MODULE_DEVICE_TABLE(of, milbeaut_updown_cnt_of_match);
>> +
>> +static struct platform_driver milbeaut_updown_cnt_driver = {
>> + .probe = milbeaut_updown_cnt_probe,
>> + .driver = {
>> + .name = "milbeaut-updown-counter",
>> + .of_match_table = milbeaut_updown_cnt_of_match,
>> + },
>> +};
>> +module_platform_driver(milbeaut_updown_cnt_driver);
>> +
>> +MODULE_AUTHOR("Shinji Kanematsu <kanematsu.shinji@...ionext.com>");
>> +MODULE_DESCRIPTION("Milbeaut Updown counter");
>> +MODULE_ALIAS("platform:milbeaut_updown_counter");
>> +MODULE_LICENSE("GPL v2");
>
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