Commit | Line | Data |
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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
6057d40f YT |
2 | /* |
3 | * AMD Promontory GPIO driver | |
4 | * | |
5 | * Copyright (C) 2015 ASMedia Technology Inc. | |
6 | * Author: YD Tseng <yd_tseng@asmedia.com.tw> | |
6057d40f YT |
7 | */ |
8 | ||
9 | #include <linux/kernel.h> | |
10 | #include <linux/module.h> | |
11 | #include <linux/gpio/driver.h> | |
12 | #include <linux/spinlock.h> | |
13 | #include <linux/acpi.h> | |
14 | #include <linux/platform_device.h> | |
15 | ||
16 | #define PT_TOTAL_GPIO 8 | |
17 | ||
18 | /* PCI-E MMIO register offsets */ | |
19 | #define PT_DIRECTION_REG 0x00 | |
20 | #define PT_INPUTDATA_REG 0x04 | |
21 | #define PT_OUTPUTDATA_REG 0x08 | |
22 | #define PT_CLOCKRATE_REG 0x0C | |
23 | #define PT_SYNC_REG 0x28 | |
24 | ||
25 | struct pt_gpio_chip { | |
26 | struct gpio_chip gc; | |
27 | void __iomem *reg_base; | |
6057d40f YT |
28 | }; |
29 | ||
6057d40f YT |
30 | static int pt_gpio_request(struct gpio_chip *gc, unsigned offset) |
31 | { | |
fb722887 | 32 | struct pt_gpio_chip *pt_gpio = gpiochip_get_data(gc); |
6057d40f YT |
33 | unsigned long flags; |
34 | u32 using_pins; | |
35 | ||
58383c78 | 36 | dev_dbg(gc->parent, "pt_gpio_request offset=%x\n", offset); |
6057d40f | 37 | |
574b782e | 38 | spin_lock_irqsave(&gc->bgpio_lock, flags); |
6057d40f YT |
39 | |
40 | using_pins = readl(pt_gpio->reg_base + PT_SYNC_REG); | |
41 | if (using_pins & BIT(offset)) { | |
58383c78 LW |
42 | dev_warn(gc->parent, "PT GPIO pin %x reconfigured\n", |
43 | offset); | |
574b782e | 44 | spin_unlock_irqrestore(&gc->bgpio_lock, flags); |
6057d40f YT |
45 | return -EINVAL; |
46 | } | |
47 | ||
48 | writel(using_pins | BIT(offset), pt_gpio->reg_base + PT_SYNC_REG); | |
49 | ||
574b782e | 50 | spin_unlock_irqrestore(&gc->bgpio_lock, flags); |
6057d40f YT |
51 | |
52 | return 0; | |
53 | } | |
54 | ||
55 | static void pt_gpio_free(struct gpio_chip *gc, unsigned offset) | |
56 | { | |
fb722887 | 57 | struct pt_gpio_chip *pt_gpio = gpiochip_get_data(gc); |
6057d40f YT |
58 | unsigned long flags; |
59 | u32 using_pins; | |
60 | ||
574b782e | 61 | spin_lock_irqsave(&gc->bgpio_lock, flags); |
6057d40f YT |
62 | |
63 | using_pins = readl(pt_gpio->reg_base + PT_SYNC_REG); | |
64 | using_pins &= ~BIT(offset); | |
65 | writel(using_pins, pt_gpio->reg_base + PT_SYNC_REG); | |
66 | ||
574b782e | 67 | spin_unlock_irqrestore(&gc->bgpio_lock, flags); |
6057d40f | 68 | |
58383c78 | 69 | dev_dbg(gc->parent, "pt_gpio_free offset=%x\n", offset); |
6057d40f YT |
70 | } |
71 | ||
6057d40f YT |
72 | static int pt_gpio_probe(struct platform_device *pdev) |
73 | { | |
74 | struct device *dev = &pdev->dev; | |
75 | struct acpi_device *acpi_dev; | |
76 | acpi_handle handle = ACPI_HANDLE(dev); | |
77 | struct pt_gpio_chip *pt_gpio; | |
6057d40f YT |
78 | int ret = 0; |
79 | ||
80 | if (acpi_bus_get_device(handle, &acpi_dev)) { | |
81 | dev_err(dev, "PT GPIO device node not found\n"); | |
82 | return -ENODEV; | |
83 | } | |
84 | ||
85 | pt_gpio = devm_kzalloc(dev, sizeof(struct pt_gpio_chip), GFP_KERNEL); | |
86 | if (!pt_gpio) | |
87 | return -ENOMEM; | |
88 | ||
bb17a27a | 89 | pt_gpio->reg_base = devm_platform_ioremap_resource(pdev, 0); |
6057d40f | 90 | if (IS_ERR(pt_gpio->reg_base)) { |
2b3fee36 | 91 | dev_err(dev, "Failed to map MMIO resource for PT GPIO.\n"); |
6057d40f YT |
92 | return PTR_ERR(pt_gpio->reg_base); |
93 | } | |
94 | ||
574b782e AL |
95 | ret = bgpio_init(&pt_gpio->gc, dev, 4, |
96 | pt_gpio->reg_base + PT_INPUTDATA_REG, | |
97 | pt_gpio->reg_base + PT_OUTPUTDATA_REG, NULL, | |
98 | pt_gpio->reg_base + PT_DIRECTION_REG, NULL, | |
99 | BGPIOF_READ_OUTPUT_REG_SET); | |
100 | if (ret) { | |
2b3fee36 | 101 | dev_err(dev, "bgpio_init failed\n"); |
574b782e AL |
102 | return ret; |
103 | } | |
6057d40f | 104 | |
6057d40f | 105 | pt_gpio->gc.owner = THIS_MODULE; |
6057d40f YT |
106 | pt_gpio->gc.request = pt_gpio_request; |
107 | pt_gpio->gc.free = pt_gpio_free; | |
6057d40f YT |
108 | pt_gpio->gc.ngpio = PT_TOTAL_GPIO; |
109 | #if defined(CONFIG_OF_GPIO) | |
2b3fee36 | 110 | pt_gpio->gc.of_node = dev->of_node; |
6057d40f | 111 | #endif |
fb722887 | 112 | ret = gpiochip_add_data(&pt_gpio->gc, pt_gpio); |
6057d40f | 113 | if (ret) { |
2b3fee36 | 114 | dev_err(dev, "Failed to register GPIO lib\n"); |
6057d40f YT |
115 | return ret; |
116 | } | |
117 | ||
118 | platform_set_drvdata(pdev, pt_gpio); | |
119 | ||
120 | /* initialize register setting */ | |
121 | writel(0, pt_gpio->reg_base + PT_SYNC_REG); | |
122 | writel(0, pt_gpio->reg_base + PT_CLOCKRATE_REG); | |
123 | ||
2b3fee36 | 124 | dev_dbg(dev, "PT GPIO driver loaded\n"); |
6057d40f YT |
125 | return ret; |
126 | } | |
127 | ||
128 | static int pt_gpio_remove(struct platform_device *pdev) | |
129 | { | |
130 | struct pt_gpio_chip *pt_gpio = platform_get_drvdata(pdev); | |
131 | ||
132 | gpiochip_remove(&pt_gpio->gc); | |
133 | ||
134 | return 0; | |
135 | } | |
136 | ||
137 | static const struct acpi_device_id pt_gpio_acpi_match[] = { | |
138 | { "AMDF030", 0 }, | |
ca27379f | 139 | { "AMDIF030", 0 }, |
6057d40f YT |
140 | { }, |
141 | }; | |
142 | MODULE_DEVICE_TABLE(acpi, pt_gpio_acpi_match); | |
143 | ||
144 | static struct platform_driver pt_gpio_driver = { | |
145 | .driver = { | |
146 | .name = "pt-gpio", | |
147 | .acpi_match_table = ACPI_PTR(pt_gpio_acpi_match), | |
148 | }, | |
149 | .probe = pt_gpio_probe, | |
150 | .remove = pt_gpio_remove, | |
151 | }; | |
152 | ||
153 | module_platform_driver(pt_gpio_driver); | |
154 | ||
155 | MODULE_LICENSE("GPL"); | |
156 | MODULE_AUTHOR("YD Tseng <yd_tseng@asmedia.com.tw>"); | |
157 | MODULE_DESCRIPTION("AMD Promontory GPIO Driver"); |