tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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");