1 // SPDX-License-Identifier: GPL-2.0+
2 
3 /*
4  * GPIO driver for the AMD G series FCH (eg. GX-412TC)
5  *
6  * Copyright (C) 2018 metux IT consult
7  * Author: Enrico Weigelt, metux IT consult <info@metux.net>
8  *
9  */
10 
11 #include <linux/err.h>
12 #include <linux/io.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/platform_device.h>
16 #include <linux/gpio/driver.h>
17 #include <linux/platform_data/gpio/gpio-amd-fch.h>
18 #include <linux/spinlock.h>
19 
20 #define AMD_FCH_MMIO_BASE		0xFED80000
21 #define AMD_FCH_GPIO_BANK0_BASE		0x1500
22 #define AMD_FCH_GPIO_SIZE		0x0300
23 
24 #define AMD_FCH_GPIO_FLAG_DIRECTION	BIT(23)
25 #define AMD_FCH_GPIO_FLAG_WRITE		BIT(22)
26 #define AMD_FCH_GPIO_FLAG_READ		BIT(16)
27 
28 static const struct resource amd_fch_gpio_iores =
29 	DEFINE_RES_MEM_NAMED(
30 		AMD_FCH_MMIO_BASE + AMD_FCH_GPIO_BANK0_BASE,
31 		AMD_FCH_GPIO_SIZE,
32 		"amd-fch-gpio-iomem");
33 
34 struct amd_fch_gpio_priv {
35 	struct gpio_chip		gc;
36 	void __iomem			*base;
37 	struct amd_fch_gpio_pdata	*pdata;
38 	spinlock_t			lock;
39 };
40 
amd_fch_gpio_addr(struct amd_fch_gpio_priv * priv,unsigned int gpio)41 static void __iomem *amd_fch_gpio_addr(struct amd_fch_gpio_priv *priv,
42 				       unsigned int gpio)
43 {
44 	return priv->base + priv->pdata->gpio_reg[gpio]*sizeof(u32);
45 }
46 
amd_fch_gpio_direction_input(struct gpio_chip * gc,unsigned int offset)47 static int amd_fch_gpio_direction_input(struct gpio_chip *gc,
48 					unsigned int offset)
49 {
50 	unsigned long flags;
51 	struct amd_fch_gpio_priv *priv = gpiochip_get_data(gc);
52 	void __iomem *ptr = amd_fch_gpio_addr(priv, offset);
53 
54 	spin_lock_irqsave(&priv->lock, flags);
55 	writel_relaxed(readl_relaxed(ptr) & ~AMD_FCH_GPIO_FLAG_DIRECTION, ptr);
56 	spin_unlock_irqrestore(&priv->lock, flags);
57 
58 	return 0;
59 }
60 
amd_fch_gpio_direction_output(struct gpio_chip * gc,unsigned int gpio,int value)61 static int amd_fch_gpio_direction_output(struct gpio_chip *gc,
62 					 unsigned int gpio, int value)
63 {
64 	unsigned long flags;
65 	struct amd_fch_gpio_priv *priv = gpiochip_get_data(gc);
66 	void __iomem *ptr = amd_fch_gpio_addr(priv, gpio);
67 	u32 val;
68 
69 	spin_lock_irqsave(&priv->lock, flags);
70 
71 	val = readl_relaxed(ptr);
72 	if (value)
73 		val |= AMD_FCH_GPIO_FLAG_WRITE;
74 	else
75 		val &= ~AMD_FCH_GPIO_FLAG_WRITE;
76 
77 	writel_relaxed(val | AMD_FCH_GPIO_FLAG_DIRECTION, ptr);
78 
79 	spin_unlock_irqrestore(&priv->lock, flags);
80 
81 	return 0;
82 }
83 
amd_fch_gpio_get_direction(struct gpio_chip * gc,unsigned int gpio)84 static int amd_fch_gpio_get_direction(struct gpio_chip *gc, unsigned int gpio)
85 {
86 	int ret;
87 	unsigned long flags;
88 	struct amd_fch_gpio_priv *priv = gpiochip_get_data(gc);
89 	void __iomem *ptr = amd_fch_gpio_addr(priv, gpio);
90 
91 	spin_lock_irqsave(&priv->lock, flags);
92 	ret = (readl_relaxed(ptr) & AMD_FCH_GPIO_FLAG_DIRECTION);
93 	spin_unlock_irqrestore(&priv->lock, flags);
94 
95 	return ret ? GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN;
96 }
97 
amd_fch_gpio_set(struct gpio_chip * gc,unsigned int gpio,int value)98 static void amd_fch_gpio_set(struct gpio_chip *gc,
99 			     unsigned int gpio, int value)
100 {
101 	unsigned long flags;
102 	struct amd_fch_gpio_priv *priv = gpiochip_get_data(gc);
103 	void __iomem *ptr = amd_fch_gpio_addr(priv, gpio);
104 	u32 mask;
105 
106 	spin_lock_irqsave(&priv->lock, flags);
107 
108 	mask = readl_relaxed(ptr);
109 	if (value)
110 		mask |= AMD_FCH_GPIO_FLAG_WRITE;
111 	else
112 		mask &= ~AMD_FCH_GPIO_FLAG_WRITE;
113 	writel_relaxed(mask, ptr);
114 
115 	spin_unlock_irqrestore(&priv->lock, flags);
116 }
117 
amd_fch_gpio_get(struct gpio_chip * gc,unsigned int offset)118 static int amd_fch_gpio_get(struct gpio_chip *gc,
119 			    unsigned int offset)
120 {
121 	unsigned long flags;
122 	int ret;
123 	struct amd_fch_gpio_priv *priv = gpiochip_get_data(gc);
124 	void __iomem *ptr = amd_fch_gpio_addr(priv, offset);
125 
126 	spin_lock_irqsave(&priv->lock, flags);
127 	ret = (readl_relaxed(ptr) & AMD_FCH_GPIO_FLAG_READ);
128 	spin_unlock_irqrestore(&priv->lock, flags);
129 
130 	return ret;
131 }
132 
amd_fch_gpio_request(struct gpio_chip * chip,unsigned int gpio_pin)133 static int amd_fch_gpio_request(struct gpio_chip *chip,
134 				unsigned int gpio_pin)
135 {
136 	return 0;
137 }
138 
amd_fch_gpio_probe(struct platform_device * pdev)139 static int amd_fch_gpio_probe(struct platform_device *pdev)
140 {
141 	struct amd_fch_gpio_priv *priv;
142 	struct amd_fch_gpio_pdata *pdata;
143 
144 	pdata = dev_get_platdata(&pdev->dev);
145 	if (!pdata) {
146 		dev_err(&pdev->dev, "no platform_data\n");
147 		return -ENOENT;
148 	}
149 
150 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
151 	if (!priv)
152 		return -ENOMEM;
153 
154 	priv->pdata	= pdata;
155 
156 	priv->gc.owner			= THIS_MODULE;
157 	priv->gc.parent			= &pdev->dev;
158 	priv->gc.label			= dev_name(&pdev->dev);
159 	priv->gc.ngpio			= priv->pdata->gpio_num;
160 	priv->gc.names			= priv->pdata->gpio_names;
161 	priv->gc.base			= -1;
162 	priv->gc.request		= amd_fch_gpio_request;
163 	priv->gc.direction_input	= amd_fch_gpio_direction_input;
164 	priv->gc.direction_output	= amd_fch_gpio_direction_output;
165 	priv->gc.get_direction		= amd_fch_gpio_get_direction;
166 	priv->gc.get			= amd_fch_gpio_get;
167 	priv->gc.set			= amd_fch_gpio_set;
168 
169 	spin_lock_init(&priv->lock);
170 
171 	priv->base = devm_ioremap_resource(&pdev->dev, &amd_fch_gpio_iores);
172 	if (IS_ERR(priv->base))
173 		return PTR_ERR(priv->base);
174 
175 	platform_set_drvdata(pdev, priv);
176 
177 	return devm_gpiochip_add_data(&pdev->dev, &priv->gc, priv);
178 }
179 
180 static struct platform_driver amd_fch_gpio_driver = {
181 	.driver = {
182 		.name = AMD_FCH_GPIO_DRIVER_NAME,
183 	},
184 	.probe = amd_fch_gpio_probe,
185 };
186 
187 module_platform_driver(amd_fch_gpio_driver);
188 
189 MODULE_AUTHOR("Enrico Weigelt, metux IT consult <info@metux.net>");
190 MODULE_DESCRIPTION("AMD G-series FCH GPIO driver");
191 MODULE_LICENSE("GPL");
192 MODULE_ALIAS("platform:" AMD_FCH_GPIO_DRIVER_NAME);
193