1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2015 Marek Vasut <marex@denx.de>
4  *
5  * DesignWare APB GPIO driver
6  */
7 
8 #include <common.h>
9 #include <log.h>
10 #include <malloc.h>
11 #include <asm/arch/gpio.h>
12 #include <asm/gpio.h>
13 #include <asm/io.h>
14 #include <dm.h>
15 #include <dm/device-internal.h>
16 #include <dm/device_compat.h>
17 #include <dm/devres.h>
18 #include <dm/lists.h>
19 #include <dm/root.h>
20 #include <errno.h>
21 #include <reset.h>
22 #include <linux/bitops.h>
23 
24 #define GPIO_SWPORT_DR(p)	(0x00 + (p) * 0xc)
25 #define GPIO_SWPORT_DDR(p)	(0x04 + (p) * 0xc)
26 #define GPIO_INTEN		0x30
27 #define GPIO_INTMASK		0x34
28 #define GPIO_INTTYPE_LEVEL	0x38
29 #define GPIO_INT_POLARITY	0x3c
30 #define GPIO_INTSTATUS		0x40
31 #define GPIO_PORTA_DEBOUNCE	0x48
32 #define GPIO_PORTA_EOI		0x4c
33 #define GPIO_EXT_PORT(p)	(0x50 + (p) * 4)
34 
35 struct gpio_dwapb_priv {
36 	struct reset_ctl_bulk	resets;
37 };
38 
39 struct gpio_dwapb_plat {
40 	const char	*name;
41 	int		bank;
42 	int		pins;
43 	void __iomem	*base;
44 };
45 
dwapb_gpio_direction_input(struct udevice * dev,unsigned pin)46 static int dwapb_gpio_direction_input(struct udevice *dev, unsigned pin)
47 {
48 	struct gpio_dwapb_plat *plat = dev_get_plat(dev);
49 
50 	clrbits_le32(plat->base + GPIO_SWPORT_DDR(plat->bank), 1 << pin);
51 	return 0;
52 }
53 
dwapb_gpio_direction_output(struct udevice * dev,unsigned pin,int val)54 static int dwapb_gpio_direction_output(struct udevice *dev, unsigned pin,
55 				     int val)
56 {
57 	struct gpio_dwapb_plat *plat = dev_get_plat(dev);
58 
59 	setbits_le32(plat->base + GPIO_SWPORT_DDR(plat->bank), 1 << pin);
60 
61 	if (val)
62 		setbits_le32(plat->base + GPIO_SWPORT_DR(plat->bank), 1 << pin);
63 	else
64 		clrbits_le32(plat->base + GPIO_SWPORT_DR(plat->bank), 1 << pin);
65 
66 	return 0;
67 }
68 
dwapb_gpio_set_value(struct udevice * dev,unsigned pin,int val)69 static int dwapb_gpio_set_value(struct udevice *dev, unsigned pin, int val)
70 {
71 	struct gpio_dwapb_plat *plat = dev_get_plat(dev);
72 
73 	if (val)
74 		setbits_le32(plat->base + GPIO_SWPORT_DR(plat->bank), 1 << pin);
75 	else
76 		clrbits_le32(plat->base + GPIO_SWPORT_DR(plat->bank), 1 << pin);
77 
78 	return 0;
79 }
80 
dwapb_gpio_get_function(struct udevice * dev,unsigned offset)81 static int dwapb_gpio_get_function(struct udevice *dev, unsigned offset)
82 {
83 	struct gpio_dwapb_plat *plat = dev_get_plat(dev);
84 	u32 gpio;
85 
86 	gpio = readl(plat->base + GPIO_SWPORT_DDR(plat->bank));
87 
88 	if (gpio & BIT(offset))
89 		return GPIOF_OUTPUT;
90 	else
91 		return GPIOF_INPUT;
92 }
93 
dwapb_gpio_get_value(struct udevice * dev,unsigned pin)94 static int dwapb_gpio_get_value(struct udevice *dev, unsigned pin)
95 {
96 	struct gpio_dwapb_plat *plat = dev_get_plat(dev);
97 	u32 value;
98 
99 	if (dwapb_gpio_get_function(dev, pin) == GPIOF_OUTPUT)
100 		value = readl(plat->base + GPIO_SWPORT_DR(plat->bank));
101 	else
102 		value = readl(plat->base + GPIO_EXT_PORT(plat->bank));
103 	return !!(value & BIT(pin));
104 }
105 
106 static const struct dm_gpio_ops gpio_dwapb_ops = {
107 	.direction_input	= dwapb_gpio_direction_input,
108 	.direction_output	= dwapb_gpio_direction_output,
109 	.get_value		= dwapb_gpio_get_value,
110 	.set_value		= dwapb_gpio_set_value,
111 	.get_function		= dwapb_gpio_get_function,
112 };
113 
gpio_dwapb_reset(struct udevice * dev)114 static int gpio_dwapb_reset(struct udevice *dev)
115 {
116 	int ret;
117 	struct gpio_dwapb_priv *priv = dev_get_priv(dev);
118 
119 	ret = reset_get_bulk(dev, &priv->resets);
120 	if (ret) {
121 		/* Return 0 if error due to !CONFIG_DM_RESET and reset
122 		 * DT property is not present.
123 		 */
124 		if (ret == -ENOENT || ret == -ENOTSUPP)
125 			return 0;
126 
127 		dev_warn(dev, "Can't get reset: %d\n", ret);
128 		return ret;
129 	}
130 
131 	ret = reset_deassert_bulk(&priv->resets);
132 	if (ret) {
133 		reset_release_bulk(&priv->resets);
134 		dev_err(dev, "Failed to reset: %d\n", ret);
135 		return ret;
136 	}
137 
138 	return 0;
139 }
140 
gpio_dwapb_probe(struct udevice * dev)141 static int gpio_dwapb_probe(struct udevice *dev)
142 {
143 	struct gpio_dev_priv *priv = dev_get_uclass_priv(dev);
144 	struct gpio_dwapb_plat *plat = dev_get_plat(dev);
145 
146 	if (!plat) {
147 		/* Reset on parent device only */
148 		return gpio_dwapb_reset(dev);
149 	}
150 
151 	priv->gpio_count = plat->pins;
152 	priv->bank_name = plat->name;
153 
154 	return 0;
155 }
156 
gpio_dwapb_bind(struct udevice * dev)157 static int gpio_dwapb_bind(struct udevice *dev)
158 {
159 	struct gpio_dwapb_plat *plat = dev_get_plat(dev);
160 	struct udevice *subdev;
161 	fdt_addr_t base;
162 	int ret, bank = 0;
163 	ofnode node;
164 
165 	/* If this is a child device, there is nothing to do here */
166 	if (plat)
167 		return 0;
168 
169 	base = dev_read_addr(dev);
170 	if (base == FDT_ADDR_T_NONE) {
171 		debug("Can't get the GPIO register base address\n");
172 		return -ENXIO;
173 	}
174 
175 	for (node = dev_read_first_subnode(dev); ofnode_valid(node);
176 	     node = dev_read_next_subnode(node)) {
177 		if (!ofnode_read_bool(node, "gpio-controller"))
178 			continue;
179 
180 		plat = devm_kcalloc(dev, 1, sizeof(*plat), GFP_KERNEL);
181 		if (!plat)
182 			return -ENOMEM;
183 
184 		plat->base = (void *)base;
185 		plat->bank = bank;
186 		plat->pins = ofnode_read_u32_default(node, "snps,nr-gpios", 0);
187 
188 		if (ofnode_read_string_index(node, "bank-name", 0,
189 					     &plat->name)) {
190 			/*
191 			 * Fall back to node name. This means accessing pins
192 			 * via bank name won't work.
193 			 */
194 			char name[32];
195 
196 			snprintf(name, sizeof(name), "%s_",
197 				 ofnode_get_name(node));
198 			plat->name = strdup(name);
199 			if (!plat->name) {
200 				kfree(plat);
201 				return -ENOMEM;
202 			}
203 		}
204 
205 		ret = device_bind(dev, dev->driver, plat->name, plat, node,
206 				  &subdev);
207 		if (ret)
208 			return ret;
209 
210 		bank++;
211 	}
212 
213 	return 0;
214 }
215 
gpio_dwapb_remove(struct udevice * dev)216 static int gpio_dwapb_remove(struct udevice *dev)
217 {
218 	struct gpio_dwapb_plat *plat = dev_get_plat(dev);
219 	struct gpio_dwapb_priv *priv = dev_get_priv(dev);
220 
221 	if (!plat && priv)
222 		return reset_release_bulk(&priv->resets);
223 
224 	return 0;
225 }
226 
227 static const struct udevice_id gpio_dwapb_ids[] = {
228 	{ .compatible = "snps,dw-apb-gpio" },
229 	{ }
230 };
231 
232 U_BOOT_DRIVER(gpio_dwapb) = {
233 	.name		= "gpio-dwapb",
234 	.id		= UCLASS_GPIO,
235 	.of_match	= gpio_dwapb_ids,
236 	.ops		= &gpio_dwapb_ops,
237 	.bind		= gpio_dwapb_bind,
238 	.probe		= gpio_dwapb_probe,
239 	.remove		= gpio_dwapb_remove,
240 	.priv_auto	  = sizeof(struct gpio_dwapb_priv),
241 };
242