1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * This file is part of STM32 DAC driver
  4 *
  5 * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
  6 * Author: Fabrice Gasnier <fabrice.gasnier@st.com>.
  7 *
  8 */
  9
 10#include <linux/clk.h>
 11#include <linux/delay.h>
 12#include <linux/mod_devicetable.h>
 13#include <linux/module.h>
 14#include <linux/of_platform.h>
 15#include <linux/platform_device.h>
 16#include <linux/pm_runtime.h>
 17#include <linux/property.h>
 18#include <linux/regulator/consumer.h>
 19#include <linux/reset.h>
 20
 21#include "stm32-dac-core.h"
 22
 23/**
 24 * struct stm32_dac_priv - stm32 DAC core private data
 25 * @pclk:		peripheral clock common for all DACs
 26 * @vref:		regulator reference
 27 * @common:		Common data for all DAC instances
 28 */
 29struct stm32_dac_priv {
 30	struct clk *pclk;
 31	struct regulator *vref;
 32	struct stm32_dac_common common;
 33};
 34
 35/**
 36 * struct stm32_dac_cfg - DAC configuration
 37 * @has_hfsel: DAC has high frequency control
 38 */
 39struct stm32_dac_cfg {
 40	bool has_hfsel;
 41};
 42
 43static struct stm32_dac_priv *to_stm32_dac_priv(struct stm32_dac_common *com)
 44{
 45	return container_of(com, struct stm32_dac_priv, common);
 46}
 47
 48static const struct regmap_config stm32_dac_regmap_cfg = {
 49	.reg_bits = 32,
 50	.val_bits = 32,
 51	.reg_stride = sizeof(u32),
 52	.max_register = 0x3fc,
 53};
 54
 55static int stm32_dac_core_hw_start(struct device *dev)
 56{
 57	struct stm32_dac_common *common = dev_get_drvdata(dev);
 58	struct stm32_dac_priv *priv = to_stm32_dac_priv(common);
 59	int ret;
 60
 61	ret = regulator_enable(priv->vref);
 62	if (ret < 0) {
 63		dev_err(dev, "vref enable failed: %d\n", ret);
 64		return ret;
 65	}
 66
 67	ret = clk_prepare_enable(priv->pclk);
 68	if (ret < 0) {
 69		dev_err(dev, "pclk enable failed: %d\n", ret);
 70		goto err_regulator_disable;
 71	}
 72
 73	return 0;
 74
 75err_regulator_disable:
 76	regulator_disable(priv->vref);
 77
 78	return ret;
 79}
 80
 81static void stm32_dac_core_hw_stop(struct device *dev)
 82{
 83	struct stm32_dac_common *common = dev_get_drvdata(dev);
 84	struct stm32_dac_priv *priv = to_stm32_dac_priv(common);
 85
 86	clk_disable_unprepare(priv->pclk);
 87	regulator_disable(priv->vref);
 88}
 89
 90static int stm32_dac_probe(struct platform_device *pdev)
 91{
 92	struct device *dev = &pdev->dev;
 93	const struct stm32_dac_cfg *cfg;
 94	struct stm32_dac_priv *priv;
 95	struct regmap *regmap;
 96	void __iomem *mmio;
 97	struct reset_control *rst;
 98	int ret;
 99
100	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
101	if (!priv)
102		return -ENOMEM;
103	platform_set_drvdata(pdev, &priv->common);
104
105	cfg = device_get_match_data(dev);
106
107	mmio = devm_platform_ioremap_resource(pdev, 0);
108	if (IS_ERR(mmio))
109		return PTR_ERR(mmio);
110
111	regmap = devm_regmap_init_mmio_clk(dev, "pclk", mmio,
112					   &stm32_dac_regmap_cfg);
113	if (IS_ERR(regmap))
114		return PTR_ERR(regmap);
115	priv->common.regmap = regmap;
116
117	priv->pclk = devm_clk_get(dev, "pclk");
118	if (IS_ERR(priv->pclk))
119		return dev_err_probe(dev, PTR_ERR(priv->pclk), "pclk get failed\n");
120
121	priv->vref = devm_regulator_get(dev, "vref");
122	if (IS_ERR(priv->vref))
123		return dev_err_probe(dev, PTR_ERR(priv->vref), "vref get failed\n");
124
125	pm_runtime_get_noresume(dev);
126	pm_runtime_set_active(dev);
127	pm_runtime_enable(dev);
128
129	ret = stm32_dac_core_hw_start(dev);
130	if (ret)
131		goto err_pm_stop;
132
133	ret = regulator_get_voltage(priv->vref);
134	if (ret < 0) {
135		dev_err(dev, "vref get voltage failed, %d\n", ret);
136		goto err_hw_stop;
137	}
138	priv->common.vref_mv = ret / 1000;
139	dev_dbg(dev, "vref+=%dmV\n", priv->common.vref_mv);
140
141	rst = devm_reset_control_get_optional_exclusive(dev, NULL);
142	if (rst) {
143		if (IS_ERR(rst)) {
144			ret = dev_err_probe(dev, PTR_ERR(rst), "reset get failed\n");
145			goto err_hw_stop;
146		}
147
148		reset_control_assert(rst);
149		udelay(2);
150		reset_control_deassert(rst);
151	}
152
153	if (cfg && cfg->has_hfsel) {
154		/* When clock speed is higher than 80MHz, set HFSEL */
155		priv->common.hfsel = (clk_get_rate(priv->pclk) > 80000000UL);
156		ret = regmap_update_bits(regmap, STM32_DAC_CR,
157					 STM32H7_DAC_CR_HFSEL,
158					 priv->common.hfsel ?
159					 STM32H7_DAC_CR_HFSEL : 0);
160		if (ret)
161			goto err_hw_stop;
162	}
163
164
165	ret = of_platform_populate(pdev->dev.of_node, NULL, NULL, dev);
166	if (ret < 0) {
167		dev_err(dev, "failed to populate DT children\n");
168		goto err_hw_stop;
169	}
170
171	pm_runtime_put(dev);
172
173	return 0;
174
175err_hw_stop:
176	stm32_dac_core_hw_stop(dev);
177err_pm_stop:
178	pm_runtime_disable(dev);
179	pm_runtime_set_suspended(dev);
180	pm_runtime_put_noidle(dev);
181
182	return ret;
183}
184
185static void stm32_dac_remove(struct platform_device *pdev)
186{
187	pm_runtime_get_sync(&pdev->dev);
188	of_platform_depopulate(&pdev->dev);
189	stm32_dac_core_hw_stop(&pdev->dev);
190	pm_runtime_disable(&pdev->dev);
191	pm_runtime_set_suspended(&pdev->dev);
192	pm_runtime_put_noidle(&pdev->dev);
193}
194
195static int stm32_dac_core_resume(struct device *dev)
196{
197	struct stm32_dac_common *common = dev_get_drvdata(dev);
198	struct stm32_dac_priv *priv = to_stm32_dac_priv(common);
199	int ret;
200
201	if (priv->common.hfsel) {
202		/* restore hfsel (maybe lost under low power state) */
203		ret = regmap_set_bits(priv->common.regmap, STM32_DAC_CR,
204				      STM32H7_DAC_CR_HFSEL);
205		if (ret)
206			return ret;
207	}
208
209	return pm_runtime_force_resume(dev);
210}
211
212static int stm32_dac_core_runtime_suspend(struct device *dev)
213{
214	stm32_dac_core_hw_stop(dev);
215
216	return 0;
217}
218
219static int stm32_dac_core_runtime_resume(struct device *dev)
220{
221	return stm32_dac_core_hw_start(dev);
222}
223
224static const struct dev_pm_ops stm32_dac_core_pm_ops = {
225	SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, stm32_dac_core_resume)
226	RUNTIME_PM_OPS(stm32_dac_core_runtime_suspend,
227		       stm32_dac_core_runtime_resume,
228		       NULL)
229};
230
231static const struct stm32_dac_cfg stm32h7_dac_cfg = {
232	.has_hfsel = true,
233};
234
235static const struct of_device_id stm32_dac_of_match[] = {
236	{
237		.compatible = "st,stm32f4-dac-core",
238	}, {
239		.compatible = "st,stm32h7-dac-core",
240		.data = (void *)&stm32h7_dac_cfg,
241	},
242	{},
243};
244MODULE_DEVICE_TABLE(of, stm32_dac_of_match);
245
246static struct platform_driver stm32_dac_driver = {
247	.probe = stm32_dac_probe,
248	.remove = stm32_dac_remove,
249	.driver = {
250		.name = "stm32-dac-core",
251		.of_match_table = stm32_dac_of_match,
252		.pm = pm_ptr(&stm32_dac_core_pm_ops),
253	},
254};
255module_platform_driver(stm32_dac_driver);
256
257MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
258MODULE_DESCRIPTION("STMicroelectronics STM32 DAC core driver");
259MODULE_LICENSE("GPL v2");
260MODULE_ALIAS("platform:stm32-dac-core");