tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * This file is part of STM32 DAC driver
3 *
4 * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
5 * Author: Fabrice Gasnier <fabrice.gasnier@st.com>.
6 *
7 * License type: GPLv2
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License version 2 as published by
11 * the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
15 * or FITNESS FOR A PARTICULAR PURPOSE.
16 * See the GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License along with
19 * this program. If not, see <http://www.gnu.org/licenses/>.
20 */
21
22#include <linux/clk.h>
23#include <linux/delay.h>
24#include <linux/module.h>
25#include <linux/of_platform.h>
26#include <linux/regulator/consumer.h>
27#include <linux/reset.h>
28
29#include "stm32-dac-core.h"
30
31/**
32 * struct stm32_dac_priv - stm32 DAC core private data
33 * @pclk: peripheral clock common for all DACs
34 * @rst: peripheral reset control
35 * @vref: regulator reference
36 * @common: Common data for all DAC instances
37 */
38struct stm32_dac_priv {
39 struct clk *pclk;
40 struct reset_control *rst;
41 struct regulator *vref;
42 struct stm32_dac_common common;
43};
44
45static struct stm32_dac_priv *to_stm32_dac_priv(struct stm32_dac_common *com)
46{
47 return container_of(com, struct stm32_dac_priv, common);
48}
49
50static const struct regmap_config stm32_dac_regmap_cfg = {
51 .reg_bits = 32,
52 .val_bits = 32,
53 .reg_stride = sizeof(u32),
54 .max_register = 0x3fc,
55};
56
57static int stm32_dac_probe(struct platform_device *pdev)
58{
59 struct device *dev = &pdev->dev;
60 struct stm32_dac_priv *priv;
61 struct regmap *regmap;
62 struct resource *res;
63 void __iomem *mmio;
64 int ret;
65
66 if (!dev->of_node)
67 return -ENODEV;
68
69 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
70 if (!priv)
71 return -ENOMEM;
72
73 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
74 mmio = devm_ioremap_resource(dev, res);
75 if (IS_ERR(mmio))
76 return PTR_ERR(mmio);
77
78 regmap = devm_regmap_init_mmio(dev, mmio, &stm32_dac_regmap_cfg);
79 if (IS_ERR(regmap))
80 return PTR_ERR(regmap);
81 priv->common.regmap = regmap;
82
83 priv->vref = devm_regulator_get(dev, "vref");
84 if (IS_ERR(priv->vref)) {
85 ret = PTR_ERR(priv->vref);
86 dev_err(dev, "vref get failed, %d\n", ret);
87 return ret;
88 }
89
90 ret = regulator_enable(priv->vref);
91 if (ret < 0) {
92 dev_err(dev, "vref enable failed\n");
93 return ret;
94 }
95
96 ret = regulator_get_voltage(priv->vref);
97 if (ret < 0) {
98 dev_err(dev, "vref get voltage failed, %d\n", ret);
99 goto err_vref;
100 }
101 priv->common.vref_mv = ret / 1000;
102 dev_dbg(dev, "vref+=%dmV\n", priv->common.vref_mv);
103
104 priv->pclk = devm_clk_get(dev, "pclk");
105 if (IS_ERR(priv->pclk)) {
106 ret = PTR_ERR(priv->pclk);
107 dev_err(dev, "pclk get failed\n");
108 goto err_vref;
109 }
110
111 ret = clk_prepare_enable(priv->pclk);
112 if (ret < 0) {
113 dev_err(dev, "pclk enable failed\n");
114 goto err_vref;
115 }
116
117 priv->rst = devm_reset_control_get(dev, NULL);
118 if (!IS_ERR(priv->rst)) {
119 reset_control_assert(priv->rst);
120 udelay(2);
121 reset_control_deassert(priv->rst);
122 }
123
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, STM32H7_DAC_CR_HFSEL,
127 priv->common.hfsel ? STM32H7_DAC_CR_HFSEL : 0);
128 if (ret)
129 goto err_pclk;
130
131 platform_set_drvdata(pdev, &priv->common);
132
133 ret = of_platform_populate(pdev->dev.of_node, NULL, NULL, dev);
134 if (ret < 0) {
135 dev_err(dev, "failed to populate DT children\n");
136 goto err_pclk;
137 }
138
139 return 0;
140
141err_pclk:
142 clk_disable_unprepare(priv->pclk);
143err_vref:
144 regulator_disable(priv->vref);
145
146 return ret;
147}
148
149static int stm32_dac_remove(struct platform_device *pdev)
150{
151 struct stm32_dac_common *common = platform_get_drvdata(pdev);
152 struct stm32_dac_priv *priv = to_stm32_dac_priv(common);
153
154 of_platform_depopulate(&pdev->dev);
155 clk_disable_unprepare(priv->pclk);
156 regulator_disable(priv->vref);
157
158 return 0;
159}
160
161static const struct of_device_id stm32_dac_of_match[] = {
162 { .compatible = "st,stm32h7-dac-core", },
163 {},
164};
165MODULE_DEVICE_TABLE(of, stm32_dac_of_match);
166
167static struct platform_driver stm32_dac_driver = {
168 .probe = stm32_dac_probe,
169 .remove = stm32_dac_remove,
170 .driver = {
171 .name = "stm32-dac-core",
172 .of_match_table = stm32_dac_of_match,
173 },
174};
175module_platform_driver(stm32_dac_driver);
176
177MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
178MODULE_DESCRIPTION("STMicroelectronics STM32 DAC core driver");
179MODULE_LICENSE("GPL v2");
180MODULE_ALIAS("platform:stm32-dac-core");