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/module.h>
 13#include <linux/of_platform.h>
 14#include <linux/regulator/consumer.h>
 15#include <linux/reset.h>
 16
 17#include "stm32-dac-core.h"
 18
 19/**
 20 * struct stm32_dac_priv - stm32 DAC core private data
 21 * @pclk:		peripheral clock common for all DACs
 22 * @rst:		peripheral reset control
 23 * @vref:		regulator reference
 24 * @common:		Common data for all DAC instances
 25 */
 26struct stm32_dac_priv {
 27	struct clk *pclk;
 28	struct reset_control *rst;
 29	struct regulator *vref;
 30	struct stm32_dac_common common;
 31};
 32
 33/**
 34 * struct stm32_dac_cfg - DAC configuration
 35 * @has_hfsel: DAC has high frequency control
 36 */
 37struct stm32_dac_cfg {
 38	bool has_hfsel;
 39};
 40
 41static struct stm32_dac_priv *to_stm32_dac_priv(struct stm32_dac_common *com)
 42{
 43	return container_of(com, struct stm32_dac_priv, common);
 44}
 45
 46static const struct regmap_config stm32_dac_regmap_cfg = {
 47	.reg_bits = 32,
 48	.val_bits = 32,
 49	.reg_stride = sizeof(u32),
 50	.max_register = 0x3fc,
 51};
 52
 53static int stm32_dac_probe(struct platform_device *pdev)
 54{
 55	struct device *dev = &pdev->dev;
 56	const struct stm32_dac_cfg *cfg;
 57	struct stm32_dac_priv *priv;
 58	struct regmap *regmap;
 59	struct resource *res;
 60	void __iomem *mmio;
 61	int ret;
 62
 63	if (!dev->of_node)
 64		return -ENODEV;
 65
 66	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 67	if (!priv)
 68		return -ENOMEM;
 69	cfg = (const struct stm32_dac_cfg *)
 70		of_match_device(dev->driver->of_match_table, dev)->data;
 71
 72	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 73	mmio = devm_ioremap_resource(dev, res);
 74	if (IS_ERR(mmio))
 75		return PTR_ERR(mmio);
 76
 77	regmap = devm_regmap_init_mmio(dev, mmio, &stm32_dac_regmap_cfg);
 78	if (IS_ERR(regmap))
 79		return PTR_ERR(regmap);
 80	priv->common.regmap = regmap;
 81
 82	priv->vref = devm_regulator_get(dev, "vref");
 83	if (IS_ERR(priv->vref)) {
 84		ret = PTR_ERR(priv->vref);
 85		dev_err(dev, "vref get failed, %d\n", ret);
 86		return ret;
 87	}
 88
 89	ret = regulator_enable(priv->vref);
 90	if (ret < 0) {
 91		dev_err(dev, "vref enable failed\n");
 92		return ret;
 93	}
 94
 95	ret = regulator_get_voltage(priv->vref);
 96	if (ret < 0) {
 97		dev_err(dev, "vref get voltage failed, %d\n", ret);
 98		goto err_vref;
 99	}
100	priv->common.vref_mv = ret / 1000;
101	dev_dbg(dev, "vref+=%dmV\n", priv->common.vref_mv);
102
103	priv->pclk = devm_clk_get(dev, "pclk");
104	if (IS_ERR(priv->pclk)) {
105		ret = PTR_ERR(priv->pclk);
106		dev_err(dev, "pclk get failed\n");
107		goto err_vref;
108	}
109
110	ret = clk_prepare_enable(priv->pclk);
111	if (ret < 0) {
112		dev_err(dev, "pclk enable failed\n");
113		goto err_vref;
114	}
115
116	priv->rst = devm_reset_control_get_exclusive(dev, NULL);
117	if (!IS_ERR(priv->rst)) {
118		reset_control_assert(priv->rst);
119		udelay(2);
120		reset_control_deassert(priv->rst);
121	}
122
123	if (cfg && cfg->has_hfsel) {
124		/* When clock speed is higher than 80MHz, set HFSEL */
125		priv->common.hfsel = (clk_get_rate(priv->pclk) > 80000000UL);
126		ret = regmap_update_bits(regmap, STM32_DAC_CR,
127					 STM32H7_DAC_CR_HFSEL,
128					 priv->common.hfsel ?
129					 STM32H7_DAC_CR_HFSEL : 0);
130		if (ret)
131			goto err_pclk;
132	}
133
134	platform_set_drvdata(pdev, &priv->common);
135
136	ret = of_platform_populate(pdev->dev.of_node, NULL, NULL, dev);
137	if (ret < 0) {
138		dev_err(dev, "failed to populate DT children\n");
139		goto err_pclk;
140	}
141
142	return 0;
143
144err_pclk:
145	clk_disable_unprepare(priv->pclk);
146err_vref:
147	regulator_disable(priv->vref);
148
149	return ret;
150}
151
152static int stm32_dac_remove(struct platform_device *pdev)
153{
154	struct stm32_dac_common *common = platform_get_drvdata(pdev);
155	struct stm32_dac_priv *priv = to_stm32_dac_priv(common);
156
157	of_platform_depopulate(&pdev->dev);
158	clk_disable_unprepare(priv->pclk);
159	regulator_disable(priv->vref);
160
161	return 0;
162}
163
164static const struct stm32_dac_cfg stm32h7_dac_cfg = {
165	.has_hfsel = true,
166};
167
168static const struct of_device_id stm32_dac_of_match[] = {
169	{
170		.compatible = "st,stm32f4-dac-core",
171	}, {
172		.compatible = "st,stm32h7-dac-core",
173		.data = (void *)&stm32h7_dac_cfg,
174	},
175	{},
176};
177MODULE_DEVICE_TABLE(of, stm32_dac_of_match);
178
179static struct platform_driver stm32_dac_driver = {
180	.probe = stm32_dac_probe,
181	.remove = stm32_dac_remove,
182	.driver = {
183		.name = "stm32-dac-core",
184		.of_match_table = stm32_dac_of_match,
185	},
186};
187module_platform_driver(stm32_dac_driver);
188
189MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
190MODULE_DESCRIPTION("STMicroelectronics STM32 DAC core driver");
191MODULE_LICENSE("GPL v2");
192MODULE_ALIAS("platform:stm32-dac-core");