1 /*
2 * Copyright (c) 2017 BayLibre, SAS.
3 * Author: Jerome Brunet <jbrunet@baylibre.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of version 2 of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, see <http://www.gnu.org/licenses/>.
16 * The full GNU General Public License is included in this distribution
17 * in the file called COPYING.
18 */
19
20 #include <linux/gpio/consumer.h>
21 #include <linux/module.h>
22 #include <sound/soc.h>
23
24 #define DRV_NAME "simple-amplifier"
25
26 struct simple_amp {
27 struct gpio_desc *gpiod_enable;
28 };
29
drv_event(struct snd_soc_dapm_widget * w,struct snd_kcontrol * control,int event)30 static int drv_event(struct snd_soc_dapm_widget *w,
31 struct snd_kcontrol *control, int event)
32 {
33 struct snd_soc_component *c = snd_soc_dapm_to_component(w->dapm);
34 struct simple_amp *priv = snd_soc_component_get_drvdata(c);
35 int val;
36
37 switch (event) {
38 case SND_SOC_DAPM_POST_PMU:
39 val = 1;
40 break;
41 case SND_SOC_DAPM_PRE_PMD:
42 val = 0;
43 break;
44 default:
45 WARN(1, "Unexpected event");
46 return -EINVAL;
47 }
48
49 gpiod_set_value_cansleep(priv->gpiod_enable, val);
50
51 return 0;
52 }
53
54 static const struct snd_soc_dapm_widget simple_amp_dapm_widgets[] = {
55 SND_SOC_DAPM_INPUT("INL"),
56 SND_SOC_DAPM_INPUT("INR"),
57 SND_SOC_DAPM_OUT_DRV_E("DRV", SND_SOC_NOPM, 0, 0, NULL, 0, drv_event,
58 (SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_PRE_PMD)),
59 SND_SOC_DAPM_OUTPUT("OUTL"),
60 SND_SOC_DAPM_OUTPUT("OUTR"),
61 };
62
63 static const struct snd_soc_dapm_route simple_amp_dapm_routes[] = {
64 { "DRV", NULL, "INL" },
65 { "DRV", NULL, "INR" },
66 { "OUTL", NULL, "DRV" },
67 { "OUTR", NULL, "DRV" },
68 };
69
70 static const struct snd_soc_component_driver simple_amp_component_driver = {
71 .dapm_widgets = simple_amp_dapm_widgets,
72 .num_dapm_widgets = ARRAY_SIZE(simple_amp_dapm_widgets),
73 .dapm_routes = simple_amp_dapm_routes,
74 .num_dapm_routes = ARRAY_SIZE(simple_amp_dapm_routes),
75 };
76
simple_amp_probe(struct platform_device * pdev)77 static int simple_amp_probe(struct platform_device *pdev)
78 {
79 struct device *dev = &pdev->dev;
80 struct simple_amp *priv;
81 int err;
82
83 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
84 if (priv == NULL)
85 return -ENOMEM;
86 platform_set_drvdata(pdev, priv);
87
88 priv->gpiod_enable = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
89 if (IS_ERR(priv->gpiod_enable)) {
90 err = PTR_ERR(priv->gpiod_enable);
91 if (err != -EPROBE_DEFER)
92 dev_err(dev, "Failed to get 'enable' gpio: %d", err);
93 return err;
94 }
95
96 return devm_snd_soc_register_component(dev,
97 &simple_amp_component_driver,
98 NULL, 0);
99 }
100
101 #ifdef CONFIG_OF
102 static const struct of_device_id simple_amp_ids[] = {
103 { .compatible = "dioo,dio2125", },
104 { .compatible = "simple-audio-amplifier", },
105 { }
106 };
107 MODULE_DEVICE_TABLE(of, simple_amp_ids);
108 #endif
109
110 static struct platform_driver simple_amp_driver = {
111 .driver = {
112 .name = DRV_NAME,
113 .of_match_table = of_match_ptr(simple_amp_ids),
114 },
115 .probe = simple_amp_probe,
116 };
117
118 module_platform_driver(simple_amp_driver);
119
120 MODULE_DESCRIPTION("ASoC Simple Audio Amplifier driver");
121 MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
122 MODULE_LICENSE("GPL");
123
