summaryrefslogtreecommitdiff
path: root/src/drivers/uart/acpi/acpi.c
blob: d4b14aac044345798430cd2861845635a0edc810 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
/* SPDX-License-Identifier: GPL-2.0-or-later */

#include <acpi/acpi_device.h>
#include <acpi/acpigen.h>
#include <console/console.h>
#include <device/path.h>
#include <string.h>
#include "chip.h"

static bool uart_acpi_add_gpios_to_crs(struct drivers_uart_acpi_config *config)
{
	/*
	 * Return false if:
	 * 1. Request to explicitly disable export of GPIOs in CRS, or
	 * 2. Both reset and enable GPIOs are not provided.
	 */
	if (config->disable_gpio_export_in_crs ||
	    ((config->reset_gpio.pin_count == 0) &&
	     (config->enable_gpio.pin_count == 0)))
		return false;

	return true;
}

static int uart_acpi_write_gpio(struct acpi_gpio *gpio, int *curr_index)
{
	int ret = -1;

	if (gpio->pin_count == 0)
		return ret;

	acpi_device_write_gpio(gpio);
	ret = *curr_index;
	(*curr_index)++;

	return ret;
}

static void uart_acpi_fill_ssdt(const struct device *dev)
{
	const char *scope = acpi_device_scope(dev);
	const char *path = acpi_device_path(dev);
	struct drivers_uart_acpi_config *config = dev->chip_info;
	int curr_index = 0;
	int irq_gpio_index = -1;
	int reset_gpio_index = -1;
	int enable_gpio_index = -1;

	if (!scope)
		return;

	if (!config->hid) {
		printk(BIOS_ERR, "%s: ERROR: HID required\n", dev_path(dev));
		return;
	}

	acpigen_write_scope(scope);
	acpigen_write_device(acpi_device_name(dev));

	acpigen_write_name_string("_HID", config->hid);
	if (config->cid)
		acpigen_write_name_string("_CID", config->cid);
	acpigen_write_name_integer("_UID", config->uid);
	acpigen_write_name_string("_DDN", config->desc);
	acpigen_write_STA(acpi_device_status(dev));

	/* Resources */
	acpigen_write_name("_CRS");
	acpigen_write_resourcetemplate_header();

	/* Fix up resource pointer to this scope */
	config->uart.resource = scope;
	acpi_device_write_uart(&config->uart);

	/* Use either Interrupt() or GpioInt() */
	if (config->irq_gpio.pin_count)
		acpi_device_write_gpio(&config->irq_gpio);
	else
		acpi_device_write_interrupt(&config->irq);

	/* Add enable/reset GPIOs if needed */
	if (uart_acpi_add_gpios_to_crs(config)) {
		reset_gpio_index = uart_acpi_write_gpio(&config->reset_gpio,
							&curr_index);
		enable_gpio_index = uart_acpi_write_gpio(&config->enable_gpio,
							 &curr_index);
	}
	acpigen_write_resourcetemplate_footer();

	/* Wake capabilities */
	if (config->wake) {
		acpigen_write_name_integer("_S0W", ACPI_DEVICE_SLEEP_D3_COLD);
		acpigen_write_PRW(config->wake, SLP_TYP_S3);
	};

	/* Write device properties if needed */
	if (config->compat_string || irq_gpio_index >= 0 ||
	    reset_gpio_index >= 0 || enable_gpio_index >= 0) {
		struct acpi_dp *dsd = acpi_dp_new_table("_DSD");
		if (config->compat_string)
			acpi_dp_add_string(dsd, "compatible",
					   config->compat_string);
		if (irq_gpio_index >= 0)
			acpi_dp_add_gpio(dsd, "irq-gpios", path,
					 irq_gpio_index, 0,
					 config->irq_gpio.active_low);
		if (reset_gpio_index >= 0)
			acpi_dp_add_gpio(dsd, "reset-gpios", path,
					 reset_gpio_index, 0,
					 config->reset_gpio.active_low);
		if (enable_gpio_index >= 0)
			acpi_dp_add_gpio(dsd, "enable-gpios", path,
					 enable_gpio_index, 0,
					 config->enable_gpio.active_low);
		acpi_dp_write(dsd);
	}

	/* Power Resource */
	if (config->has_power_resource) {
		const struct acpi_power_res_params power_res_params = {
			&config->reset_gpio,
			config->reset_delay_ms,
			config->reset_off_delay_ms,
			&config->enable_gpio,
			config->enable_delay_ms,
			config->enable_off_delay_ms,
			&config->stop_gpio,
			config->stop_delay_ms,
			config->stop_off_delay_ms
		};
		acpi_device_add_power_res(&power_res_params);
	}

	acpigen_pop_len(); /* Device */
	acpigen_pop_len(); /* Scope */

	printk(BIOS_INFO, "%s: %s at %s\n", path, config->desc, dev_path(dev));
}

static const char *uart_acpi_name(const struct device *dev)
{
	struct drivers_uart_acpi_config *config = dev->chip_info;
	static char name[5];

	if (config->name)
		return config->name;

	snprintf(name, sizeof(name), "D%03.3X", dev->path.generic.id);
	return name;
}

static struct device_operations uart_acpi_dev_ops = {
	.read_resources	= noop_read_resources,
	.set_resources	= noop_set_resources,
	.acpi_fill_ssdt	= uart_acpi_fill_ssdt,
	.acpi_name	= uart_acpi_name,
};

static void uart_acpi_enable(struct device *dev)
{
	struct drivers_uart_acpi_config *config = dev->chip_info;

	if (config->desc)
		dev->name = config->desc;
	else
		config->desc = dev->chip_ops->name;

	dev->ops = &uart_acpi_dev_ops;
}

struct chip_operations drivers_uart_acpi_ops = {
	CHIP_NAME("ACPI UART Device")
	.enable_dev = uart_acpi_enable
};