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 return !!(ioread32(chip->base + bank_offset) & BIT(bit_offset));
84 }
85
xgene_gpio_dir_in(struct gpio_chip * gc,unsigned int offset)86 static int xgene_gpio_dir_in(struct gpio_chip *gc, unsigned int offset)
87 {
88 struct xgene_gpio *chip = gpiochip_get_data(gc);
89 unsigned long flags, bank_offset;
90 u32 dirval, bit_offset;
91
92 bank_offset = GPIO_SET_DR_OFFSET + GPIO_BANK_OFFSET(offset);
93 bit_offset = GPIO_BIT_OFFSET(offset);
94
95 spin_lock_irqsave(&chip->lock, flags);
96
97 dirval = ioread32(chip->base + bank_offset);
98 dirval |= BIT(bit_offset);
99 iowrite32(dirval, chip->base + bank_offset);
100
101 spin_unlock_irqrestore(&chip->lock, flags);
102
103 return 0;
104 }
105
xgene_gpio_dir_out(struct gpio_chip * gc,unsigned int offset,int val)106 static int xgene_gpio_dir_out(struct gpio_chip *gc,
107 unsigned int offset, int val)
108 {
109 struct xgene_gpio *chip = gpiochip_get_data(gc);
110 unsigned long flags, bank_offset;
111 u32 dirval, bit_offset;
112
113 bank_offset = GPIO_SET_DR_OFFSET + GPIO_BANK_OFFSET(offset);
114 bit_offset = GPIO_BIT_OFFSET(offset);
115
116 spin_lock_irqsave(&chip->lock, flags);
117
118 dirval = ioread32(chip->base + bank_offset);
119 dirval &= ~BIT(bit_offset);
120 iowrite32(dirval, chip->base + bank_offset);
121 __xgene_gpio_set(gc, offset, val);
122
123 spin_unlock_irqrestore(&chip->lock, flags);
124
125 return 0;
126 }
127
xgene_gpio_suspend(struct device * dev)128 static __maybe_unused int xgene_gpio_suspend(struct device *dev)
129 {
130 struct xgene_gpio *gpio = dev_get_drvdata(dev);
131 unsigned long bank_offset;
132 unsigned int bank;
133
134 for (bank = 0; bank < XGENE_MAX_GPIO_BANKS; bank++) {
135 bank_offset = GPIO_SET_DR_OFFSET + bank * GPIO_BANK_STRIDE;
136 gpio->set_dr_val[bank] = ioread32(gpio->base + bank_offset);
137 }
138 return 0;
139 }
140
xgene_gpio_resume(struct device * dev)141 static __maybe_unused int xgene_gpio_resume(struct device *dev)
142 {
143 struct xgene_gpio *gpio = dev_get_drvdata(dev);
144 unsigned long bank_offset;
145 unsigned int bank;
146
147 for (bank = 0; bank < XGENE_MAX_GPIO_BANKS; bank++) {
148 bank_offset = GPIO_SET_DR_OFFSET + bank * GPIO_BANK_STRIDE;
149 iowrite32(gpio->set_dr_val[bank], gpio->base + bank_offset);
150 }
151 return 0;
152 }
153
154 static SIMPLE_DEV_PM_OPS(xgene_gpio_pm, xgene_gpio_suspend, xgene_gpio_resume);
155
xgene_gpio_probe(struct platform_device * pdev)156 static int xgene_gpio_probe(struct platform_device *pdev)
157 {
158 struct resource *res;
159 struct xgene_gpio *gpio;
160 int err = 0;
161
162 gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
163 if (!gpio) {
164 err = -ENOMEM;
165 goto err;
166 }
167
168 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
169 if (!res) {
170 err = -EINVAL;
171 goto err;
172 }
173
174 gpio->base = devm_ioremap_nocache(&pdev->dev, res->start,
175 resource_size(res));
176 if (!gpio->base) {
177 err = -ENOMEM;
178 goto err;
179 }
180
181 gpio->chip.ngpio = XGENE_MAX_GPIOS;
182
183 spin_lock_init(&gpio->lock);
184 gpio->chip.parent = &pdev->dev;
185 gpio->chip.get_direction = xgene_gpio_get_direction;
186 gpio->chip.direction_input = xgene_gpio_dir_in;
187 gpio->chip.direction_output = xgene_gpio_dir_out;
188 gpio->chip.get = xgene_gpio_get;
189 gpio->chip.set = xgene_gpio_set;
190 gpio->chip.label = dev_name(&pdev->dev);
191 gpio->chip.base = -1;
192
193 platform_set_drvdata(pdev, gpio);
194
195 err = devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio);
196 if (err) {
197 dev_err(&pdev->dev,
198 "failed to register gpiochip.\n");
199 goto err;
200 }
201
202 dev_info(&pdev->dev, "X-Gene GPIO driver registered.\n");
203 return 0;
204 err:
205 dev_err(&pdev->dev, "X-Gene GPIO driver registration failed.\n");
206 return err;
207 }
208
209 static const struct of_device_id xgene_gpio_of_match[] = {
210 { .compatible = "apm,xgene-gpio", },
211 {},
212 };
213
214 #ifdef CONFIG_ACPI
215 static const struct acpi_device_id xgene_gpio_acpi_match[] = {
216 { "APMC0D14", 0 },
217 { },
218 };
219 #endif
220
221 static struct platform_driver xgene_gpio_driver = {
222 .driver = {
223 .name = "xgene-gpio",
224 .of_match_table = xgene_gpio_of_match,
225 .acpi_match_table = ACPI_PTR(xgene_gpio_acpi_match),
226 .pm = &xgene_gpio_pm,
227 },
228 .probe = xgene_gpio_probe,
229 };
230 builtin_platform_driver(xgene_gpio_driver);
231