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 <[email protected]> wrote:Add support for Milbeaut Updown Counter, that can be used as counter or quadrature encoder. Signed-off-by: Shinji Kanematsu <[email protected]>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_CNTTo compile this driver as a module, choose M here: themodule 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-$(CONFIG_104_QUAD_8) += 104-quad-8.oobj-$(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 <[email protected]>"); +MODULE_DESCRIPTION("Milbeaut Updown counter"); +MODULE_ALIAS("platform:milbeaut_updown_counter"); +MODULE_LICENSE("GPL v2");
