1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * max98357a.c -- MAX98357A Audio driver
4  *
5  * Copyright 2019 Google LLC
6  * Parts taken from coreboot
7  */
8 
9 #include <common.h>
10 #include <audio_codec.h>
11 #include <dm.h>
12 #include <log.h>
13 #include <sound.h>
14 #include <acpi/acpigen.h>
15 #include <acpi/acpi_device.h>
16 #include <acpi/acpi_dp.h>
17 #include <asm-generic/gpio.h>
18 #ifdef CONFIG_X86
19 #include <asm/acpi_nhlt.h>
20 #endif
21 #include <dt-bindings/sound/nhlt.h>
22 #include <dm/acpi.h>
23 
24 struct max98357a_priv {
25 	struct gpio_desc sdmode_gpio;
26 };
27 
max98357a_of_to_plat(struct udevice * dev)28 static int max98357a_of_to_plat(struct udevice *dev)
29 {
30 	struct max98357a_priv *priv = dev_get_priv(dev);
31 	int ret;
32 
33 	ret = gpio_request_by_name(dev, "sdmode-gpios", 0, &priv->sdmode_gpio,
34 				   GPIOD_IS_IN);
35 	if (ret)
36 		return log_msg_ret("gpio", ret);
37 
38 	return 0;
39 }
40 
max98357a_acpi_fill_ssdt(const struct udevice * dev,struct acpi_ctx * ctx)41 static int max98357a_acpi_fill_ssdt(const struct udevice *dev,
42 				    struct acpi_ctx *ctx)
43 {
44 	struct max98357a_priv *priv = dev_get_priv(dev);
45 	char scope[ACPI_PATH_MAX];
46 	char name[ACPI_NAME_MAX];
47 	char path[ACPI_PATH_MAX];
48 	struct acpi_dp *dp;
49 	int ret;
50 
51 	ret = acpi_device_scope(dev, scope, sizeof(scope));
52 	if (ret)
53 		return log_msg_ret("scope", ret);
54 	ret = acpi_get_name(dev, name);
55 	if (ret)
56 		return log_msg_ret("name", ret);
57 
58 	/* Device */
59 	acpigen_write_scope(ctx, scope);
60 	acpigen_write_device(ctx, name);
61 	acpigen_write_name_string(ctx, "_HID",
62 				  dev_read_string(dev, "acpi,hid"));
63 	acpigen_write_name_integer(ctx, "_UID", 0);
64 	acpigen_write_name_string(ctx, "_DDN",
65 				  dev_read_string(dev, "acpi,ddn"));
66 	acpigen_write_sta(ctx, acpi_device_status(dev));
67 
68 	/* Resources */
69 	acpigen_write_name(ctx, "_CRS");
70 	acpigen_write_resourcetemplate_header(ctx);
71 	ret = acpi_device_write_gpio_desc(ctx, &priv->sdmode_gpio);
72 	if (ret < 0)
73 		return log_msg_ret("gpio", ret);
74 	acpigen_write_resourcetemplate_footer(ctx);
75 
76 	/* _DSD for devicetree properties */
77 	/* This points to the first pin in the first gpio entry in _CRS */
78 	ret = acpi_device_path(dev, path, sizeof(path));
79 	if (ret)
80 		return log_msg_ret("path", ret);
81 	dp = acpi_dp_new_table("_DSD");
82 	acpi_dp_add_gpio(dp, "sdmode-gpio", path, 0, 0,
83 			 priv->sdmode_gpio.flags & GPIOD_ACTIVE_LOW ?
84 			 ACPI_GPIO_ACTIVE_LOW : ACPI_GPIO_ACTIVE_HIGH);
85 	acpi_dp_add_integer(dp, "sdmode-delay",
86 			    dev_read_u32_default(dev, "sdmode-delay", 0));
87 	acpi_dp_write(ctx, dp);
88 
89 	acpigen_pop_len(ctx); /* Device */
90 	acpigen_pop_len(ctx); /* Scope */
91 
92 	return 0;
93 }
94 
95 /* For now only X86 boards support NHLT */
96 #ifdef CONFIG_X86
97 static const struct nhlt_format_config max98357a_formats[] = {
98 	/* 48 KHz 24-bits per sample. */
99 	{
100 		.num_channels = 2,
101 		.sample_freq_khz = 48,
102 		.container_bits_per_sample = 32,
103 		.valid_bits_per_sample = 24,
104 		.settings_file = "max98357-render-2ch-48khz-24b.dat",
105 	},
106 };
107 
108 static const struct nhlt_endp_descriptor max98357a_descriptors[] = {
109 	{
110 		.link = NHLT_LINK_SSP,
111 		.device = NHLT_SSP_DEV_I2S,
112 		.direction = NHLT_DIR_RENDER,
113 		.vid = NHLT_VID,
114 		.did = NHLT_DID_SSP,
115 		.formats = max98357a_formats,
116 		.num_formats = ARRAY_SIZE(max98357a_formats),
117 	},
118 };
119 
max98357a_acpi_setup_nhlt(const struct udevice * dev,struct acpi_ctx * ctx)120 static int max98357a_acpi_setup_nhlt(const struct udevice *dev,
121 				     struct acpi_ctx *ctx)
122 {
123 	u32 hwlink;
124 	int ret;
125 
126 	if (dev_read_u32(dev, "acpi,audio-link", &hwlink))
127 		return log_msg_ret("link", -EINVAL);
128 
129 	/* Virtual bus id of SSP links are the hardware port ids proper. */
130 	ret = nhlt_add_ssp_endpoints(ctx->nhlt, hwlink, max98357a_descriptors,
131 				     ARRAY_SIZE(max98357a_descriptors));
132 	if (ret)
133 		return log_msg_ret("add", ret);
134 
135 	return 0;
136 }
137 #endif
138 
139 struct acpi_ops max98357a_acpi_ops = {
140 	.fill_ssdt	= max98357a_acpi_fill_ssdt,
141 #ifdef CONFIG_X86
142 	.setup_nhlt	= max98357a_acpi_setup_nhlt,
143 #endif
144 };
145 
146 static const struct audio_codec_ops max98357a_ops = {
147 };
148 
149 static const struct udevice_id max98357a_ids[] = {
150 	{ .compatible = "maxim,max98357a" },
151 	{ }
152 };
153 
154 U_BOOT_DRIVER(max98357a) = {
155 	.name		= "max98357a",
156 	.id		= UCLASS_AUDIO_CODEC,
157 	.of_match	= max98357a_ids,
158 	.of_to_plat	= max98357a_of_to_plat,
159 	.ops		= &max98357a_ops,
160 	ACPI_OPS_PTR(&max98357a_acpi_ops)
161 };
162