Re: [PATCH 2/2] iio: counter: Add support for Milbeaut Updown Counter
From: Kanematsu, Shinji/åæ äæ
Date: Tue Apr 02 2019 - 01:30:34 EST
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@xxxxxxxxxxxxx> wrote:
Add support for Milbeaut Updown Counter, that can be used as counter
or quadrature encoder.
Signed-off-by: Shinji Kanematsu <kanematsu.shinji@xxxxxxxxxxxxx>
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@xxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Milbeaut Updown counter");
+MODULE_ALIAS("platform:milbeaut_updown_counter");
+MODULE_LICENSE("GPL v2");