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6057d40f YT |
1 | /* |
2 | * AMD Promontory GPIO driver | |
3 | * | |
4 | * Copyright (C) 2015 ASMedia Technology Inc. | |
5 | * Author: YD Tseng <yd_tseng@asmedia.com.tw> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | */ | |
11 | ||
12 | #include <linux/kernel.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/gpio/driver.h> | |
15 | #include <linux/spinlock.h> | |
16 | #include <linux/acpi.h> | |
17 | #include <linux/platform_device.h> | |
18 | ||
19 | #define PT_TOTAL_GPIO 8 | |
20 | ||
21 | /* PCI-E MMIO register offsets */ | |
22 | #define PT_DIRECTION_REG 0x00 | |
23 | #define PT_INPUTDATA_REG 0x04 | |
24 | #define PT_OUTPUTDATA_REG 0x08 | |
25 | #define PT_CLOCKRATE_REG 0x0C | |
26 | #define PT_SYNC_REG 0x28 | |
27 | ||
28 | struct pt_gpio_chip { | |
29 | struct gpio_chip gc; | |
30 | void __iomem *reg_base; | |
31 | spinlock_t lock; | |
32 | }; | |
33 | ||
6057d40f YT |
34 | static int pt_gpio_request(struct gpio_chip *gc, unsigned offset) |
35 | { | |
fb722887 | 36 | struct pt_gpio_chip *pt_gpio = gpiochip_get_data(gc); |
6057d40f YT |
37 | unsigned long flags; |
38 | u32 using_pins; | |
39 | ||
58383c78 | 40 | dev_dbg(gc->parent, "pt_gpio_request offset=%x\n", offset); |
6057d40f YT |
41 | |
42 | spin_lock_irqsave(&pt_gpio->lock, flags); | |
43 | ||
44 | using_pins = readl(pt_gpio->reg_base + PT_SYNC_REG); | |
45 | if (using_pins & BIT(offset)) { | |
58383c78 LW |
46 | dev_warn(gc->parent, "PT GPIO pin %x reconfigured\n", |
47 | offset); | |
6057d40f YT |
48 | spin_unlock_irqrestore(&pt_gpio->lock, flags); |
49 | return -EINVAL; | |
50 | } | |
51 | ||
52 | writel(using_pins | BIT(offset), pt_gpio->reg_base + PT_SYNC_REG); | |
53 | ||
54 | spin_unlock_irqrestore(&pt_gpio->lock, flags); | |
55 | ||
56 | return 0; | |
57 | } | |
58 | ||
59 | static void pt_gpio_free(struct gpio_chip *gc, unsigned offset) | |
60 | { | |
fb722887 | 61 | struct pt_gpio_chip *pt_gpio = gpiochip_get_data(gc); |
6057d40f YT |
62 | unsigned long flags; |
63 | u32 using_pins; | |
64 | ||
65 | spin_lock_irqsave(&pt_gpio->lock, flags); | |
66 | ||
67 | using_pins = readl(pt_gpio->reg_base + PT_SYNC_REG); | |
68 | using_pins &= ~BIT(offset); | |
69 | writel(using_pins, pt_gpio->reg_base + PT_SYNC_REG); | |
70 | ||
71 | spin_unlock_irqrestore(&pt_gpio->lock, flags); | |
72 | ||
58383c78 | 73 | dev_dbg(gc->parent, "pt_gpio_free offset=%x\n", offset); |
6057d40f YT |
74 | } |
75 | ||
76 | static void pt_gpio_set_value(struct gpio_chip *gc, unsigned offset, int value) | |
77 | { | |
fb722887 | 78 | struct pt_gpio_chip *pt_gpio = gpiochip_get_data(gc); |
6057d40f YT |
79 | unsigned long flags; |
80 | u32 data; | |
81 | ||
58383c78 | 82 | dev_dbg(gc->parent, "pt_gpio_set_value offset=%x, value=%x\n", |
6057d40f YT |
83 | offset, value); |
84 | ||
85 | spin_lock_irqsave(&pt_gpio->lock, flags); | |
86 | ||
87 | data = readl(pt_gpio->reg_base + PT_OUTPUTDATA_REG); | |
88 | data &= ~BIT(offset); | |
89 | if (value) | |
90 | data |= BIT(offset); | |
91 | writel(data, pt_gpio->reg_base + PT_OUTPUTDATA_REG); | |
92 | ||
93 | spin_unlock_irqrestore(&pt_gpio->lock, flags); | |
94 | } | |
95 | ||
96 | static int pt_gpio_get_value(struct gpio_chip *gc, unsigned offset) | |
97 | { | |
fb722887 | 98 | struct pt_gpio_chip *pt_gpio = gpiochip_get_data(gc); |
6057d40f YT |
99 | unsigned long flags; |
100 | u32 data; | |
101 | ||
102 | spin_lock_irqsave(&pt_gpio->lock, flags); | |
103 | ||
104 | data = readl(pt_gpio->reg_base + PT_DIRECTION_REG); | |
105 | ||
106 | /* configure as output */ | |
107 | if (data & BIT(offset)) | |
108 | data = readl(pt_gpio->reg_base + PT_OUTPUTDATA_REG); | |
109 | else /* configure as input */ | |
110 | data = readl(pt_gpio->reg_base + PT_INPUTDATA_REG); | |
111 | ||
112 | spin_unlock_irqrestore(&pt_gpio->lock, flags); | |
113 | ||
114 | data >>= offset; | |
115 | data &= 1; | |
116 | ||
58383c78 | 117 | dev_dbg(gc->parent, "pt_gpio_get_value offset=%x, value=%x\n", |
6057d40f YT |
118 | offset, data); |
119 | ||
120 | return data; | |
121 | } | |
122 | ||
123 | static int pt_gpio_direction_input(struct gpio_chip *gc, unsigned offset) | |
124 | { | |
fb722887 | 125 | struct pt_gpio_chip *pt_gpio = gpiochip_get_data(gc); |
6057d40f YT |
126 | unsigned long flags; |
127 | u32 data; | |
128 | ||
58383c78 | 129 | dev_dbg(gc->parent, "pt_gpio_dirction_input offset=%x\n", offset); |
6057d40f YT |
130 | |
131 | spin_lock_irqsave(&pt_gpio->lock, flags); | |
132 | ||
133 | data = readl(pt_gpio->reg_base + PT_DIRECTION_REG); | |
134 | data &= ~BIT(offset); | |
135 | writel(data, pt_gpio->reg_base + PT_DIRECTION_REG); | |
136 | ||
137 | spin_unlock_irqrestore(&pt_gpio->lock, flags); | |
138 | ||
139 | return 0; | |
140 | } | |
141 | ||
142 | static int pt_gpio_direction_output(struct gpio_chip *gc, | |
143 | unsigned offset, int value) | |
144 | { | |
fb722887 | 145 | struct pt_gpio_chip *pt_gpio = gpiochip_get_data(gc); |
6057d40f YT |
146 | unsigned long flags; |
147 | u32 data; | |
148 | ||
58383c78 | 149 | dev_dbg(gc->parent, "pt_gpio_direction_output offset=%x, value=%x\n", |
6057d40f YT |
150 | offset, value); |
151 | ||
152 | spin_lock_irqsave(&pt_gpio->lock, flags); | |
153 | ||
154 | data = readl(pt_gpio->reg_base + PT_OUTPUTDATA_REG); | |
155 | if (value) | |
156 | data |= BIT(offset); | |
157 | else | |
158 | data &= ~BIT(offset); | |
159 | writel(data, pt_gpio->reg_base + PT_OUTPUTDATA_REG); | |
160 | ||
161 | data = readl(pt_gpio->reg_base + PT_DIRECTION_REG); | |
162 | data |= BIT(offset); | |
163 | writel(data, pt_gpio->reg_base + PT_DIRECTION_REG); | |
164 | ||
165 | spin_unlock_irqrestore(&pt_gpio->lock, flags); | |
166 | ||
167 | return 0; | |
168 | } | |
169 | ||
170 | static int pt_gpio_probe(struct platform_device *pdev) | |
171 | { | |
172 | struct device *dev = &pdev->dev; | |
173 | struct acpi_device *acpi_dev; | |
174 | acpi_handle handle = ACPI_HANDLE(dev); | |
175 | struct pt_gpio_chip *pt_gpio; | |
176 | struct resource *res_mem; | |
177 | int ret = 0; | |
178 | ||
179 | if (acpi_bus_get_device(handle, &acpi_dev)) { | |
180 | dev_err(dev, "PT GPIO device node not found\n"); | |
181 | return -ENODEV; | |
182 | } | |
183 | ||
184 | pt_gpio = devm_kzalloc(dev, sizeof(struct pt_gpio_chip), GFP_KERNEL); | |
185 | if (!pt_gpio) | |
186 | return -ENOMEM; | |
187 | ||
188 | res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
189 | if (!res_mem) { | |
190 | dev_err(&pdev->dev, "Failed to get MMIO resource for PT GPIO.\n"); | |
191 | return -EINVAL; | |
192 | } | |
193 | pt_gpio->reg_base = devm_ioremap_resource(dev, res_mem); | |
194 | if (IS_ERR(pt_gpio->reg_base)) { | |
195 | dev_err(&pdev->dev, "Failed to map MMIO resource for PT GPIO.\n"); | |
196 | return PTR_ERR(pt_gpio->reg_base); | |
197 | } | |
198 | ||
199 | spin_lock_init(&pt_gpio->lock); | |
200 | ||
201 | pt_gpio->gc.label = pdev->name; | |
202 | pt_gpio->gc.owner = THIS_MODULE; | |
58383c78 | 203 | pt_gpio->gc.parent = dev; |
6057d40f YT |
204 | pt_gpio->gc.request = pt_gpio_request; |
205 | pt_gpio->gc.free = pt_gpio_free; | |
206 | pt_gpio->gc.direction_input = pt_gpio_direction_input; | |
207 | pt_gpio->gc.direction_output = pt_gpio_direction_output; | |
208 | pt_gpio->gc.get = pt_gpio_get_value; | |
209 | pt_gpio->gc.set = pt_gpio_set_value; | |
210 | pt_gpio->gc.base = -1; | |
211 | pt_gpio->gc.ngpio = PT_TOTAL_GPIO; | |
212 | #if defined(CONFIG_OF_GPIO) | |
213 | pt_gpio->gc.of_node = pdev->dev.of_node; | |
214 | #endif | |
fb722887 | 215 | ret = gpiochip_add_data(&pt_gpio->gc, pt_gpio); |
6057d40f YT |
216 | if (ret) { |
217 | dev_err(&pdev->dev, "Failed to register GPIO lib\n"); | |
218 | return ret; | |
219 | } | |
220 | ||
221 | platform_set_drvdata(pdev, pt_gpio); | |
222 | ||
223 | /* initialize register setting */ | |
224 | writel(0, pt_gpio->reg_base + PT_SYNC_REG); | |
225 | writel(0, pt_gpio->reg_base + PT_CLOCKRATE_REG); | |
226 | ||
227 | dev_dbg(&pdev->dev, "PT GPIO driver loaded\n"); | |
228 | return ret; | |
229 | } | |
230 | ||
231 | static int pt_gpio_remove(struct platform_device *pdev) | |
232 | { | |
233 | struct pt_gpio_chip *pt_gpio = platform_get_drvdata(pdev); | |
234 | ||
235 | gpiochip_remove(&pt_gpio->gc); | |
236 | ||
237 | return 0; | |
238 | } | |
239 | ||
240 | static const struct acpi_device_id pt_gpio_acpi_match[] = { | |
241 | { "AMDF030", 0 }, | |
242 | { }, | |
243 | }; | |
244 | MODULE_DEVICE_TABLE(acpi, pt_gpio_acpi_match); | |
245 | ||
246 | static struct platform_driver pt_gpio_driver = { | |
247 | .driver = { | |
248 | .name = "pt-gpio", | |
249 | .acpi_match_table = ACPI_PTR(pt_gpio_acpi_match), | |
250 | }, | |
251 | .probe = pt_gpio_probe, | |
252 | .remove = pt_gpio_remove, | |
253 | }; | |
254 | ||
255 | module_platform_driver(pt_gpio_driver); | |
256 | ||
257 | MODULE_LICENSE("GPL"); | |
258 | MODULE_AUTHOR("YD Tseng <yd_tseng@asmedia.com.tw>"); | |
259 | MODULE_DESCRIPTION("AMD Promontory GPIO Driver"); |