1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * AppliedMicro X-Gene SoC GPIO Driver
4  *
5  * Copyright (c) 2014, Applied Micro Circuits Corporation
6  * Author: Feng Kan <fkan@apm.com>.
7  */
8 
9 #include <linux/acpi.h>
10 #include <linux/kernel.h>
11 #include <linux/init.h>
12 #include <linux/io.h>
13 #include <linux/spinlock.h>
14 #include <linux/platform_device.h>
15 #include <linux/gpio/driver.h>
16 #include <linux/types.h>
17 #include <linux/bitops.h>
18 
19 #define GPIO_SET_DR_OFFSET	0x0C
20 #define GPIO_DATA_OFFSET	0x14
21 #define GPIO_BANK_STRIDE	0x0C
22 
23 #define XGENE_GPIOS_PER_BANK	16
24 #define XGENE_MAX_GPIO_BANKS	3
25 #define XGENE_MAX_GPIOS		(XGENE_GPIOS_PER_BANK * XGENE_MAX_GPIO_BANKS)
26 
27 #define GPIO_BIT_OFFSET(x)	(x % XGENE_GPIOS_PER_BANK)
28 #define GPIO_BANK_OFFSET(x)	((x / XGENE_GPIOS_PER_BANK) * GPIO_BANK_STRIDE)
29 
30 struct xgene_gpio {
31 	struct gpio_chip	chip;
32 	void __iomem		*base;
33 	spinlock_t		lock;
34 	u32			set_dr_val[XGENE_MAX_GPIO_BANKS];
35 };
36 
xgene_gpio_get(struct gpio_chip * gc,unsigned int offset)37 static int xgene_gpio_get(struct gpio_chip *gc, unsigned int offset)
38 {
39 	struct xgene_gpio *chip = gpiochip_get_data(gc);
40 	unsigned long bank_offset;
41 	u32 bit_offset;
42 
43 	bank_offset = GPIO_DATA_OFFSET + GPIO_BANK_OFFSET(offset);
44 	bit_offset = GPIO_BIT_OFFSET(offset);
45 	return !!(ioread32(chip->base + bank_offset) & BIT(bit_offset));
46 }
47 
__xgene_gpio_set(struct gpio_chip * gc,unsigned int offset,int val)48 static void __xgene_gpio_set(struct gpio_chip *gc, unsigned int offset, int val)
49 {
50 	struct xgene_gpio *chip = gpiochip_get_data(gc);
51 	unsigned long bank_offset;
52 	u32 setval, bit_offset;
53 
54 	bank_offset = GPIO_SET_DR_OFFSET + GPIO_BANK_OFFSET(offset);
55 	bit_offset = GPIO_BIT_OFFSET(offset) + XGENE_GPIOS_PER_BANK;
56 
57 	setval = ioread32(chip->base + bank_offset);
58 	if (val)
59 		setval |= BIT(bit_offset);
60 	else
61 		setval &= ~BIT(bit_offset);
62 	iowrite32(setval, chip->base + bank_offset);
63 }
64 
xgene_gpio_set(struct gpio_chip * gc,unsigned int offset,int val)65 static void xgene_gpio_set(struct gpio_chip *gc, unsigned int offset, int val)
66 {
67 	struct xgene_gpio *chip = gpiochip_get_data(gc);
68 	unsigned long flags;
69 
70 	spin_lock_irqsave(&chip->lock, flags);
71 	__xgene_gpio_set(gc, offset, val);
72 	spin_unlock_irqrestore(&chip->lock, flags);
73 }
74 
xgene_gpio_get_direction(struct gpio_chip * gc,unsigned int offset)75 static int xgene_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
76 {
77 	struct xgene_gpio *chip = gpiochip_get_data(gc);
78 	unsigned long bank_offset, bit_offset;
79 
80 	bank_offset = GPIO_SET_DR_OFFSET + GPIO_BANK_OFFSET(offset);
81 	bit_offset = GPIO_BIT_OFFSET(offset);
82 
83 	if (ioread32(chip->base + bank_offset) & BIT(bit_offset))
84 		return GPIO_LINE_DIRECTION_IN;
85 
86 	return GPIO_LINE_DIRECTION_OUT;
87 }
88 
xgene_gpio_dir_in(struct gpio_chip * gc,unsigned int offset)89 static int xgene_gpio_dir_in(struct gpio_chip *gc, unsigned int offset)
90 {
91 	struct xgene_gpio *chip = gpiochip_get_data(gc);
92 	unsigned long flags, bank_offset;
93 	u32 dirval, bit_offset;
94 
95 	bank_offset = GPIO_SET_DR_OFFSET + GPIO_BANK_OFFSET(offset);
96 	bit_offset = GPIO_BIT_OFFSET(offset);
97 
98 	spin_lock_irqsave(&chip->lock, flags);
99 
100 	dirval = ioread32(chip->base + bank_offset);
101 	dirval |= BIT(bit_offset);
102 	iowrite32(dirval, chip->base + bank_offset);
103 
104 	spin_unlock_irqrestore(&chip->lock, flags);
105 
106 	return 0;
107 }
108 
xgene_gpio_dir_out(struct gpio_chip * gc,unsigned int offset,int val)109 static int xgene_gpio_dir_out(struct gpio_chip *gc,
110 					unsigned int offset, int val)
111 {
112 	struct xgene_gpio *chip = gpiochip_get_data(gc);
113 	unsigned long flags, bank_offset;
114 	u32 dirval, bit_offset;
115 
116 	bank_offset = GPIO_SET_DR_OFFSET + GPIO_BANK_OFFSET(offset);
117 	bit_offset = GPIO_BIT_OFFSET(offset);
118 
119 	spin_lock_irqsave(&chip->lock, flags);
120 
121 	dirval = ioread32(chip->base + bank_offset);
122 	dirval &= ~BIT(bit_offset);
123 	iowrite32(dirval, chip->base + bank_offset);
124 	__xgene_gpio_set(gc, offset, val);
125 
126 	spin_unlock_irqrestore(&chip->lock, flags);
127 
128 	return 0;
129 }
130 
xgene_gpio_suspend(struct device * dev)131 static __maybe_unused int xgene_gpio_suspend(struct device *dev)
132 {
133 	struct xgene_gpio *gpio = dev_get_drvdata(dev);
134 	unsigned long bank_offset;
135 	unsigned int bank;
136 
137 	for (bank = 0; bank < XGENE_MAX_GPIO_BANKS; bank++) {
138 		bank_offset = GPIO_SET_DR_OFFSET + bank * GPIO_BANK_STRIDE;
139 		gpio->set_dr_val[bank] = ioread32(gpio->base + bank_offset);
140 	}
141 	return 0;
142 }
143 
xgene_gpio_resume(struct device * dev)144 static __maybe_unused int xgene_gpio_resume(struct device *dev)
145 {
146 	struct xgene_gpio *gpio = dev_get_drvdata(dev);
147 	unsigned long bank_offset;
148 	unsigned int bank;
149 
150 	for (bank = 0; bank < XGENE_MAX_GPIO_BANKS; bank++) {
151 		bank_offset = GPIO_SET_DR_OFFSET + bank * GPIO_BANK_STRIDE;
152 		iowrite32(gpio->set_dr_val[bank], gpio->base + bank_offset);
153 	}
154 	return 0;
155 }
156 
157 static SIMPLE_DEV_PM_OPS(xgene_gpio_pm, xgene_gpio_suspend, xgene_gpio_resume);
158 
xgene_gpio_probe(struct platform_device * pdev)159 static int xgene_gpio_probe(struct platform_device *pdev)
160 {
161 	struct xgene_gpio *gpio;
162 
163 	gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
164 	if (!gpio)
165 		return -ENOMEM;
166 
167 	gpio->base = devm_platform_ioremap_resource(pdev, 0);
168 	if (IS_ERR(gpio->base))
169 		return PTR_ERR(gpio->base);
170 
171 	gpio->chip.ngpio = XGENE_MAX_GPIOS;
172 
173 	spin_lock_init(&gpio->lock);
174 	gpio->chip.parent = &pdev->dev;
175 	gpio->chip.get_direction = xgene_gpio_get_direction;
176 	gpio->chip.direction_input = xgene_gpio_dir_in;
177 	gpio->chip.direction_output = xgene_gpio_dir_out;
178 	gpio->chip.get = xgene_gpio_get;
179 	gpio->chip.set = xgene_gpio_set;
180 	gpio->chip.label = dev_name(&pdev->dev);
181 	gpio->chip.base = -1;
182 
183 	platform_set_drvdata(pdev, gpio);
184 
185 	return devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio);
186 }
187 
188 static const struct of_device_id xgene_gpio_of_match[] = {
189 	{ .compatible = "apm,xgene-gpio", },
190 	{},
191 };
192 
193 #ifdef CONFIG_ACPI
194 static const struct acpi_device_id xgene_gpio_acpi_match[] = {
195 	{ "APMC0D14", 0 },
196 	{ },
197 };
198 #endif
199 
200 static struct platform_driver xgene_gpio_driver = {
201 	.driver = {
202 		.name = "xgene-gpio",
203 		.of_match_table = xgene_gpio_of_match,
204 		.acpi_match_table = ACPI_PTR(xgene_gpio_acpi_match),
205 		.pm     = &xgene_gpio_pm,
206 	},
207 	.probe = xgene_gpio_probe,
208 };
209 builtin_platform_driver(xgene_gpio_driver);
210