1 // SPDX-License-Identifier: GPL-2.0
3  * STM32 Low-Power Timer Encoder and Counter driver
9  * Inspired by 104-quad-8 and stm32-timer-trigger drivers.
15 #include <linux/mfd/stm32-lptimer.h>
33 	ret = regmap_read(priv->regmap, STM32_LPTIM_CR, &val);  in stm32_lptim_is_enabled()
47 	ret = regmap_write(priv->regmap, STM32_LPTIM_CR, val);  in stm32_lptim_set_enable_state()
52 		clk_disable(priv->clk);  in stm32_lptim_set_enable_state()
57 	ret = regmap_write(priv->regmap, STM32_LPTIM_ARR, priv->preset);  in stm32_lptim_set_enable_state()
61 	ret = regmap_write(priv->regmap, STM32_LPTIM_CMP, 0);  in stm32_lptim_set_enable_state()
66 	ret = regmap_read_poll_timeout(priv->regmap, STM32_LPTIM_ISR, val,  in stm32_lptim_set_enable_state()
72 	ret = regmap_write(priv->regmap, STM32_LPTIM_ICR,  in stm32_lptim_set_enable_state()
77 	ret = clk_enable(priv->clk);  in stm32_lptim_set_enable_state()
79 		regmap_write(priv->regmap, STM32_LPTIM_CR, 0);  in stm32_lptim_set_enable_state()
84 	return regmap_update_bits(priv->regmap, STM32_LPTIM_CR,  in stm32_lptim_set_enable_state()
95 	if (priv->quadrature_mode)  in stm32_lptim_setup()
99 	val |= FIELD_PREP(STM32_LPTIM_CKPOL, enable ? priv->polarity : 0);  in stm32_lptim_setup()
101 	return regmap_update_bits(priv->regmap, STM32_LPTIM_CFGR, mask, val);  in stm32_lptim_setup()
114 			return -EINVAL;  in stm32_lptim_write_raw()
121 			return -EBUSY;  in stm32_lptim_write_raw()
129 		return -EINVAL;  in stm32_lptim_write_raw()
143 		ret = regmap_read(priv->regmap, STM32_LPTIM_CNT, &dat);  in stm32_lptim_read_raw()
157 		/* Non-quadrature mode: scale = 1 */  in stm32_lptim_read_raw()
160 		if (priv->quadrature_mode) {  in stm32_lptim_read_raw()
163 			 * - both edges, quarter cycle, scale is 0.25  in stm32_lptim_read_raw()
164 			 * - either rising/falling edge scale is 0.5  in stm32_lptim_read_raw()
166 			if (priv->polarity > 1)  in stm32_lptim_read_raw()
174 		return -EINVAL;  in stm32_lptim_read_raw()
184 	"non-quadrature",
193 	return priv->quadrature_mode;  in stm32_lptim_get_quadrature_mode()
203 		return -EBUSY;  in stm32_lptim_set_quadrature_mode()
205 	priv->quadrature_mode = type;  in stm32_lptim_set_quadrature_mode()
218 	"rising-edge", "falling-edge", "both-edges",
226 	return priv->polarity;  in stm32_lptim_cnt_get_polarity()
236 		return -EBUSY;  in stm32_lptim_cnt_set_polarity()
238 	priv->polarity = type;  in stm32_lptim_cnt_set_polarity()
257 	return snprintf(buf, PAGE_SIZE, "%u\n", priv->preset);  in stm32_lptim_cnt_get_preset()
269 		return -EBUSY;  in stm32_lptim_cnt_set_preset()
271 	ret = kstrtouint(buf, 0, &priv->preset);  in stm32_lptim_cnt_set_preset()
275 	if (priv->preset > STM32_LPTIM_MAX_ARR)  in stm32_lptim_cnt_set_preset()
276 		return -EINVAL;  in stm32_lptim_cnt_set_preset()
332 	struct stm32_lptimer *ddata = dev_get_drvdata(pdev->dev.parent);  in stm32_lptim_cnt_probe()
337 		return -EINVAL;  in stm32_lptim_cnt_probe()
339 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*priv));  in stm32_lptim_cnt_probe()
341 		return -ENOMEM;  in stm32_lptim_cnt_probe()
344 	priv->dev = &pdev->dev;  in stm32_lptim_cnt_probe()
345 	priv->regmap = ddata->regmap;  in stm32_lptim_cnt_probe()
346 	priv->clk = ddata->clk;  in stm32_lptim_cnt_probe()
347 	priv->preset = STM32_LPTIM_MAX_ARR;  in stm32_lptim_cnt_probe()
349 	indio_dev->name = dev_name(&pdev->dev);  in stm32_lptim_cnt_probe()
350 	indio_dev->dev.parent = &pdev->dev;  in stm32_lptim_cnt_probe()
351 	indio_dev->dev.of_node = pdev->dev.of_node;  in stm32_lptim_cnt_probe()
352 	indio_dev->info = &stm32_lptim_cnt_iio_info;  in stm32_lptim_cnt_probe()
353 	if (ddata->has_encoder)  in stm32_lptim_cnt_probe()
354 		indio_dev->channels = &stm32_lptim_enc_channels;  in stm32_lptim_cnt_probe()
356 		indio_dev->channels = &stm32_lptim_cnt_channels;  in stm32_lptim_cnt_probe()
357 	indio_dev->num_channels = 1;  in stm32_lptim_cnt_probe()
361 	return devm_iio_device_register(&pdev->dev, indio_dev);  in stm32_lptim_cnt_probe()
365 	{ .compatible = "st,stm32-lptimer-counter", },
373 		.name = "stm32-lptimer-counter",
380 MODULE_ALIAS("platform:stm32-lptimer-counter");
381 MODULE_DESCRIPTION("STMicroelectronics STM32 LPTIM counter driver");