diff options
Diffstat (limited to 'drivers/iio/counter/stm32-lptimer-cnt.c')
-rw-r--r-- | drivers/iio/counter/stm32-lptimer-cnt.c | 382 |
1 files changed, 0 insertions, 382 deletions
diff --git a/drivers/iio/counter/stm32-lptimer-cnt.c b/drivers/iio/counter/stm32-lptimer-cnt.c deleted file mode 100644 index 42fb8ba67090..000000000000 --- a/drivers/iio/counter/stm32-lptimer-cnt.c +++ /dev/null @@ -1,382 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * STM32 Low-Power Timer Encoder and Counter driver - * - * Copyright (C) STMicroelectronics 2017 - * - * Author: Fabrice Gasnier <fabrice.gasnier@st.com> - * - * Inspired by 104-quad-8 and stm32-timer-trigger drivers. - * - */ - -#include <linux/bitfield.h> -#include <linux/iio/iio.h> -#include <linux/mfd/stm32-lptimer.h> -#include <linux/module.h> -#include <linux/platform_device.h> - -struct stm32_lptim_cnt { - struct device *dev; - struct regmap *regmap; - struct clk *clk; - u32 preset; - u32 polarity; - u32 quadrature_mode; -}; - -static int stm32_lptim_is_enabled(struct stm32_lptim_cnt *priv) -{ - u32 val; - int ret; - - ret = regmap_read(priv->regmap, STM32_LPTIM_CR, &val); - if (ret) - return ret; - - return FIELD_GET(STM32_LPTIM_ENABLE, val); -} - -static int stm32_lptim_set_enable_state(struct stm32_lptim_cnt *priv, - int enable) -{ - int ret; - u32 val; - - val = FIELD_PREP(STM32_LPTIM_ENABLE, enable); - ret = regmap_write(priv->regmap, STM32_LPTIM_CR, val); - if (ret) - return ret; - - if (!enable) { - clk_disable(priv->clk); - return 0; - } - - /* LP timer must be enabled before writing CMP & ARR */ - ret = regmap_write(priv->regmap, STM32_LPTIM_ARR, priv->preset); - if (ret) - return ret; - - ret = regmap_write(priv->regmap, STM32_LPTIM_CMP, 0); - if (ret) - return ret; - - /* ensure CMP & ARR registers are properly written */ - ret = regmap_read_poll_timeout(priv->regmap, STM32_LPTIM_ISR, val, - (val & STM32_LPTIM_CMPOK_ARROK), - 100, 1000); - if (ret) - return ret; - - ret = regmap_write(priv->regmap, STM32_LPTIM_ICR, - STM32_LPTIM_CMPOKCF_ARROKCF); - if (ret) - return ret; - - ret = clk_enable(priv->clk); - if (ret) { - regmap_write(priv->regmap, STM32_LPTIM_CR, 0); - return ret; - } - - /* Start LP timer in continuous mode */ - return regmap_update_bits(priv->regmap, STM32_LPTIM_CR, - STM32_LPTIM_CNTSTRT, STM32_LPTIM_CNTSTRT); -} - -static int stm32_lptim_setup(struct stm32_lptim_cnt *priv, int enable) -{ - u32 mask = STM32_LPTIM_ENC | STM32_LPTIM_COUNTMODE | - STM32_LPTIM_CKPOL | STM32_LPTIM_PRESC; - u32 val; - - /* Setup LP timer encoder/counter and polarity, without prescaler */ - if (priv->quadrature_mode) - val = enable ? STM32_LPTIM_ENC : 0; - else - val = enable ? STM32_LPTIM_COUNTMODE : 0; - val |= FIELD_PREP(STM32_LPTIM_CKPOL, enable ? priv->polarity : 0); - - return regmap_update_bits(priv->regmap, STM32_LPTIM_CFGR, mask, val); -} - -static int stm32_lptim_write_raw(struct iio_dev *indio_dev, - struct iio_chan_spec const *chan, - int val, int val2, long mask) -{ - struct stm32_lptim_cnt *priv = iio_priv(indio_dev); - int ret; - - switch (mask) { - case IIO_CHAN_INFO_ENABLE: - if (val < 0 || val > 1) - return -EINVAL; - - /* Check nobody uses the timer, or already disabled/enabled */ - ret = stm32_lptim_is_enabled(priv); - if ((ret < 0) || (!ret && !val)) - return ret; - if (val && ret) - return -EBUSY; - - ret = stm32_lptim_setup(priv, val); - if (ret) - return ret; - return stm32_lptim_set_enable_state(priv, val); - - default: - return -EINVAL; - } -} - -static int stm32_lptim_read_raw(struct iio_dev *indio_dev, - struct iio_chan_spec const *chan, - int *val, int *val2, long mask) -{ - struct stm32_lptim_cnt *priv = iio_priv(indio_dev); - u32 dat; - int ret; - - switch (mask) { - case IIO_CHAN_INFO_RAW: - ret = regmap_read(priv->regmap, STM32_LPTIM_CNT, &dat); - if (ret) - return ret; - *val = dat; - return IIO_VAL_INT; - - case IIO_CHAN_INFO_ENABLE: - ret = stm32_lptim_is_enabled(priv); - if (ret < 0) - return ret; - *val = ret; - return IIO_VAL_INT; - - case IIO_CHAN_INFO_SCALE: - /* Non-quadrature mode: scale = 1 */ - *val = 1; - *val2 = 0; - if (priv->quadrature_mode) { - /* - * Quadrature encoder mode: - * - both edges, quarter cycle, scale is 0.25 - * - either rising/falling edge scale is 0.5 - */ - if (priv->polarity > 1) - *val2 = 2; - else - *val2 = 1; - } - return IIO_VAL_FRACTIONAL_LOG2; - - default: - return -EINVAL; - } -} - -static const struct iio_info stm32_lptim_cnt_iio_info = { - .read_raw = stm32_lptim_read_raw, - .write_raw = stm32_lptim_write_raw, -}; - -static const char *const stm32_lptim_quadrature_modes[] = { - "non-quadrature", - "quadrature", -}; - -static int stm32_lptim_get_quadrature_mode(struct iio_dev *indio_dev, - const struct iio_chan_spec *chan) -{ - struct stm32_lptim_cnt *priv = iio_priv(indio_dev); - - return priv->quadrature_mode; -} - -static int stm32_lptim_set_quadrature_mode(struct iio_dev *indio_dev, - const struct iio_chan_spec *chan, - unsigned int type) -{ - struct stm32_lptim_cnt *priv = iio_priv(indio_dev); - - if (stm32_lptim_is_enabled(priv)) - return -EBUSY; - - priv->quadrature_mode = type; - - return 0; -} - -static const struct iio_enum stm32_lptim_quadrature_mode_en = { - .items = stm32_lptim_quadrature_modes, - .num_items = ARRAY_SIZE(stm32_lptim_quadrature_modes), - .get = stm32_lptim_get_quadrature_mode, - .set = stm32_lptim_set_quadrature_mode, -}; - -static const char * const stm32_lptim_cnt_polarity[] = { - "rising-edge", "falling-edge", "both-edges", -}; - -static int stm32_lptim_cnt_get_polarity(struct iio_dev *indio_dev, - const struct iio_chan_spec *chan) -{ - struct stm32_lptim_cnt *priv = iio_priv(indio_dev); - - return priv->polarity; -} - -static int stm32_lptim_cnt_set_polarity(struct iio_dev *indio_dev, - const struct iio_chan_spec *chan, - unsigned int type) -{ - struct stm32_lptim_cnt *priv = iio_priv(indio_dev); - - if (stm32_lptim_is_enabled(priv)) - return -EBUSY; - - priv->polarity = type; - - return 0; -} - -static const struct iio_enum stm32_lptim_cnt_polarity_en = { - .items = stm32_lptim_cnt_polarity, - .num_items = ARRAY_SIZE(stm32_lptim_cnt_polarity), - .get = stm32_lptim_cnt_get_polarity, - .set = stm32_lptim_cnt_set_polarity, -}; - -static ssize_t stm32_lptim_cnt_get_preset(struct iio_dev *indio_dev, - uintptr_t private, - const struct iio_chan_spec *chan, - char *buf) -{ - struct stm32_lptim_cnt *priv = iio_priv(indio_dev); - - return snprintf(buf, PAGE_SIZE, "%u\n", priv->preset); -} - -static ssize_t stm32_lptim_cnt_set_preset(struct iio_dev *indio_dev, - uintptr_t private, - const struct iio_chan_spec *chan, - const char *buf, size_t len) -{ - struct stm32_lptim_cnt *priv = iio_priv(indio_dev); - int ret; - - if (stm32_lptim_is_enabled(priv)) - return -EBUSY; - - ret = kstrtouint(buf, 0, &priv->preset); - if (ret) - return ret; - - if (priv->preset > STM32_LPTIM_MAX_ARR) - return -EINVAL; - - return len; -} - -/* LP timer with encoder */ -static const struct iio_chan_spec_ext_info stm32_lptim_enc_ext_info[] = { - { - .name = "preset", - .shared = IIO_SEPARATE, - .read = stm32_lptim_cnt_get_preset, - .write = stm32_lptim_cnt_set_preset, - }, - IIO_ENUM("polarity", IIO_SEPARATE, &stm32_lptim_cnt_polarity_en), - IIO_ENUM_AVAILABLE("polarity", &stm32_lptim_cnt_polarity_en), - IIO_ENUM("quadrature_mode", IIO_SEPARATE, - &stm32_lptim_quadrature_mode_en), - IIO_ENUM_AVAILABLE("quadrature_mode", &stm32_lptim_quadrature_mode_en), - {} -}; - -static const struct iio_chan_spec stm32_lptim_enc_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 = stm32_lptim_enc_ext_info, - .indexed = 1, -}; - -/* LP timer without encoder (counter only) */ -static const struct iio_chan_spec_ext_info stm32_lptim_cnt_ext_info[] = { - { - .name = "preset", - .shared = IIO_SEPARATE, - .read = stm32_lptim_cnt_get_preset, - .write = stm32_lptim_cnt_set_preset, - }, - IIO_ENUM("polarity", IIO_SEPARATE, &stm32_lptim_cnt_polarity_en), - IIO_ENUM_AVAILABLE("polarity", &stm32_lptim_cnt_polarity_en), - {} -}; - -static const struct iio_chan_spec stm32_lptim_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 = stm32_lptim_cnt_ext_info, - .indexed = 1, -}; - -static int stm32_lptim_cnt_probe(struct platform_device *pdev) -{ - struct stm32_lptimer *ddata = dev_get_drvdata(pdev->dev.parent); - struct stm32_lptim_cnt *priv; - struct iio_dev *indio_dev; - - if (IS_ERR_OR_NULL(ddata)) - return -EINVAL; - - indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*priv)); - if (!indio_dev) - return -ENOMEM; - - priv = iio_priv(indio_dev); - priv->dev = &pdev->dev; - priv->regmap = ddata->regmap; - priv->clk = ddata->clk; - priv->preset = STM32_LPTIM_MAX_ARR; - - indio_dev->name = dev_name(&pdev->dev); - indio_dev->dev.parent = &pdev->dev; - indio_dev->dev.of_node = pdev->dev.of_node; - indio_dev->info = &stm32_lptim_cnt_iio_info; - if (ddata->has_encoder) - indio_dev->channels = &stm32_lptim_enc_channels; - else - indio_dev->channels = &stm32_lptim_cnt_channels; - indio_dev->num_channels = 1; - - platform_set_drvdata(pdev, priv); - - return devm_iio_device_register(&pdev->dev, indio_dev); -} - -static const struct of_device_id stm32_lptim_cnt_of_match[] = { - { .compatible = "st,stm32-lptimer-counter", }, - {}, -}; -MODULE_DEVICE_TABLE(of, stm32_lptim_cnt_of_match); - -static struct platform_driver stm32_lptim_cnt_driver = { - .probe = stm32_lptim_cnt_probe, - .driver = { - .name = "stm32-lptimer-counter", - .of_match_table = stm32_lptim_cnt_of_match, - }, -}; -module_platform_driver(stm32_lptim_cnt_driver); - -MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>"); -MODULE_ALIAS("platform:stm32-lptimer-counter"); -MODULE_DESCRIPTION("STMicroelectronics STM32 LPTIM counter driver"); -MODULE_LICENSE("GPL v2"); |