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(com: common);
59 int ret;
60
61 ret = regulator_enable(regulator: 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(clk: 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(regulator: 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(com: common);
85
86 clk_disable_unprepare(clk: priv->pclk);
87 regulator_disable(regulator: 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, size: sizeof(*priv), GFP_KERNEL);
101 if (!priv)
102 return -ENOMEM;
103 platform_set_drvdata(pdev, data: &priv->common);
104
105 cfg = device_get_match_data(dev);
106
107 mmio = devm_platform_ioremap_resource(pdev, index: 0);
108 if (IS_ERR(ptr: mmio))
109 return PTR_ERR(ptr: mmio);
110
111 regmap = devm_regmap_init_mmio_clk(dev, "pclk", mmio,
112 &stm32_dac_regmap_cfg);
113 if (IS_ERR(ptr: regmap))
114 return PTR_ERR(ptr: regmap);
115 priv->common.regmap = regmap;
116
117 priv->pclk = devm_clk_get(dev, id: "pclk");
118 if (IS_ERR(ptr: priv->pclk))
119 return dev_err_probe(dev, err: PTR_ERR(ptr: priv->pclk), fmt: "pclk get failed\n");
120
121 priv->vref = devm_regulator_get(dev, id: "vref");
122 if (IS_ERR(ptr: priv->vref))
123 return dev_err_probe(dev, err: PTR_ERR(ptr: priv->vref), fmt: "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(regulator: 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(ptr: rst)) {
144 ret = dev_err_probe(dev, err: PTR_ERR(ptr: rst), fmt: "reset get failed\n");
145 goto err_hw_stop;
146 }
147
148 reset_control_assert(rstc: rst);
149 udelay(2);
150 reset_control_deassert(rstc: 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(clk: priv->pclk) > 80000000UL);
156 ret = regmap_update_bits(map: regmap, STM32_DAC_CR,
157 STM32H7_DAC_CR_HFSEL,
158 val: 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(root: pdev->dev.of_node, NULL, NULL, parent: 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(dev: &pdev->dev);
188 of_platform_depopulate(parent: &pdev->dev);
189 stm32_dac_core_hw_stop(dev: &pdev->dev);
190 pm_runtime_disable(dev: &pdev->dev);
191 pm_runtime_set_suspended(dev: &pdev->dev);
192 pm_runtime_put_noidle(dev: &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(com: common);
199 int ret;
200
201 if (priv->common.hfsel) {
202 /* restore hfsel (maybe lost under low power state) */
203 ret = regmap_update_bits(map: priv->common.regmap, STM32_DAC_CR,
204 STM32H7_DAC_CR_HFSEL,
205 STM32H7_DAC_CR_HFSEL);
206 if (ret)
207 return ret;
208 }
209
210 return pm_runtime_force_resume(dev);
211}
212
213static int stm32_dac_core_runtime_suspend(struct device *dev)
214{
215 stm32_dac_core_hw_stop(dev);
216
217 return 0;
218}
219
220static int stm32_dac_core_runtime_resume(struct device *dev)
221{
222 return stm32_dac_core_hw_start(dev);
223}
224
225static const struct dev_pm_ops stm32_dac_core_pm_ops = {
226 SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, stm32_dac_core_resume)
227 RUNTIME_PM_OPS(stm32_dac_core_runtime_suspend,
228 stm32_dac_core_runtime_resume,
229 NULL)
230};
231
232static const struct stm32_dac_cfg stm32h7_dac_cfg = {
233 .has_hfsel = true,
234};
235
236static const struct of_device_id stm32_dac_of_match[] = {
237 {
238 .compatible = "st,stm32f4-dac-core",
239 }, {
240 .compatible = "st,stm32h7-dac-core",
241 .data = (void *)&stm32h7_dac_cfg,
242 },
243 {},
244};
245MODULE_DEVICE_TABLE(of, stm32_dac_of_match);
246
247static struct platform_driver stm32_dac_driver = {
248 .probe = stm32_dac_probe,
249 .remove_new = stm32_dac_remove,
250 .driver = {
251 .name = "stm32-dac-core",
252 .of_match_table = stm32_dac_of_match,
253 .pm = pm_ptr(&stm32_dac_core_pm_ops),
254 },
255};
256module_platform_driver(stm32_dac_driver);
257
258MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
259MODULE_DESCRIPTION("STMicroelectronics STM32 DAC core driver");
260MODULE_LICENSE("GPL v2");
261MODULE_ALIAS("platform:stm32-dac-core");
262

source code of linux/drivers/iio/dac/stm32-dac-core.c