summaryrefslogtreecommitdiff
path: root/drivers/gpio/gpio-amdpt.c
blob: 07c6d090058dd5eb1c79bd4574d1e7b0e6eac004 (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
// SPDX-License-Identifier: GPL-2.0-only
/*
 * AMD Promontory GPIO driver
 *
 * Copyright (C) 2015 ASMedia Technology Inc.
 * Author: YD Tseng <yd_tseng@asmedia.com.tw>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/gpio/driver.h>
#include <linux/spinlock.h>
#include <linux/acpi.h>
#include <linux/platform_device.h>

#define PT_TOTAL_GPIO 8
#define PT_TOTAL_GPIO_EX 24

/* PCI-E MMIO register offsets */
#define PT_DIRECTION_REG   0x00
#define PT_INPUTDATA_REG   0x04
#define PT_OUTPUTDATA_REG  0x08
#define PT_CLOCKRATE_REG   0x0C
#define PT_SYNC_REG        0x28

struct pt_gpio_chip {
	struct gpio_chip         gc;
	void __iomem             *reg_base;
};

static int pt_gpio_request(struct gpio_chip *gc, unsigned offset)
{
	struct pt_gpio_chip *pt_gpio = gpiochip_get_data(gc);
	unsigned long flags;
	u32 using_pins;

	dev_dbg(gc->parent, "pt_gpio_request offset=%x\n", offset);

	raw_spin_lock_irqsave(&gc->bgpio_lock, flags);

	using_pins = readl(pt_gpio->reg_base + PT_SYNC_REG);
	if (using_pins & BIT(offset)) {
		dev_warn(gc->parent, "PT GPIO pin %x reconfigured\n",
			 offset);
		raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);
		return -EINVAL;
	}

	writel(using_pins | BIT(offset), pt_gpio->reg_base + PT_SYNC_REG);

	raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);

	return 0;
}

static void pt_gpio_free(struct gpio_chip *gc, unsigned offset)
{
	struct pt_gpio_chip *pt_gpio = gpiochip_get_data(gc);
	unsigned long flags;
	u32 using_pins;

	raw_spin_lock_irqsave(&gc->bgpio_lock, flags);

	using_pins = readl(pt_gpio->reg_base + PT_SYNC_REG);
	using_pins &= ~BIT(offset);
	writel(using_pins, pt_gpio->reg_base + PT_SYNC_REG);

	raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);

	dev_dbg(gc->parent, "pt_gpio_free offset=%x\n", offset);
}

static int pt_gpio_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct pt_gpio_chip *pt_gpio;
	int ret = 0;

	if (!ACPI_COMPANION(dev)) {
		dev_err(dev, "PT GPIO device node not found\n");
		return -ENODEV;
	}

	pt_gpio = devm_kzalloc(dev, sizeof(struct pt_gpio_chip), GFP_KERNEL);
	if (!pt_gpio)
		return -ENOMEM;

	pt_gpio->reg_base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(pt_gpio->reg_base)) {
		dev_err(dev, "Failed to map MMIO resource for PT GPIO.\n");
		return PTR_ERR(pt_gpio->reg_base);
	}

	ret = bgpio_init(&pt_gpio->gc, dev, 4,
			 pt_gpio->reg_base + PT_INPUTDATA_REG,
			 pt_gpio->reg_base + PT_OUTPUTDATA_REG, NULL,
			 pt_gpio->reg_base + PT_DIRECTION_REG, NULL,
			 BGPIOF_READ_OUTPUT_REG_SET);
	if (ret) {
		dev_err(dev, "bgpio_init failed\n");
		return ret;
	}

	pt_gpio->gc.owner            = THIS_MODULE;
	pt_gpio->gc.request          = pt_gpio_request;
	pt_gpio->gc.free             = pt_gpio_free;
	pt_gpio->gc.ngpio            = (uintptr_t)device_get_match_data(dev);

	ret = gpiochip_add_data(&pt_gpio->gc, pt_gpio);
	if (ret) {
		dev_err(dev, "Failed to register GPIO lib\n");
		return ret;
	}

	platform_set_drvdata(pdev, pt_gpio);

	/* initialize register setting */
	writel(0, pt_gpio->reg_base + PT_SYNC_REG);
	writel(0, pt_gpio->reg_base + PT_CLOCKRATE_REG);

	dev_dbg(dev, "PT GPIO driver loaded\n");
	return ret;
}

static int pt_gpio_remove(struct platform_device *pdev)
{
	struct pt_gpio_chip *pt_gpio = platform_get_drvdata(pdev);

	gpiochip_remove(&pt_gpio->gc);

	return 0;
}

static const struct acpi_device_id pt_gpio_acpi_match[] = {
	{ "AMDF030", PT_TOTAL_GPIO },
	{ "AMDIF030", PT_TOTAL_GPIO },
	{ "AMDIF031", PT_TOTAL_GPIO_EX },
	{ },
};
MODULE_DEVICE_TABLE(acpi, pt_gpio_acpi_match);

static struct platform_driver pt_gpio_driver = {
	.driver = {
		.name = "pt-gpio",
		.acpi_match_table = ACPI_PTR(pt_gpio_acpi_match),
	},
	.probe = pt_gpio_probe,
	.remove = pt_gpio_remove,
};

module_platform_driver(pt_gpio_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("YD Tseng <yd_tseng@asmedia.com.tw>");
MODULE_DESCRIPTION("AMD Promontory GPIO Driver");