xref: /openbmc/u-boot/drivers/gpio/sandbox.c (revision e8f80a5a)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (c) 2011 The Chromium OS Authors.
4  */
5 
6 #include <common.h>
7 #include <dm.h>
8 #include <fdtdec.h>
9 #include <malloc.h>
10 #include <asm/gpio.h>
11 #include <dm/of.h>
12 #include <dt-bindings/gpio/gpio.h>
13 
14 /* Flags for each GPIO */
15 #define GPIOF_OUTPUT	(1 << 0)	/* Currently set as an output */
16 #define GPIOF_HIGH	(1 << 1)	/* Currently set high */
17 #define GPIOF_ODR	(1 << 2)	/* Currently set to open drain mode */
18 
19 struct gpio_state {
20 	const char *label;	/* label given by requester */
21 	u8 flags;		/* flags (GPIOF_...) */
22 };
23 
24 /* Access routines for GPIO state */
get_gpio_flags(struct udevice * dev,unsigned offset)25 static u8 *get_gpio_flags(struct udevice *dev, unsigned offset)
26 {
27 	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
28 	struct gpio_state *state = dev_get_priv(dev);
29 
30 	if (offset >= uc_priv->gpio_count) {
31 		static u8 invalid_flags;
32 		printf("sandbox_gpio: error: invalid gpio %u\n", offset);
33 		return &invalid_flags;
34 	}
35 
36 	return &state[offset].flags;
37 }
38 
get_gpio_flag(struct udevice * dev,unsigned offset,int flag)39 static int get_gpio_flag(struct udevice *dev, unsigned offset, int flag)
40 {
41 	return (*get_gpio_flags(dev, offset) & flag) != 0;
42 }
43 
set_gpio_flag(struct udevice * dev,unsigned offset,int flag,int value)44 static int set_gpio_flag(struct udevice *dev, unsigned offset, int flag,
45 			 int value)
46 {
47 	u8 *gpio = get_gpio_flags(dev, offset);
48 
49 	if (value)
50 		*gpio |= flag;
51 	else
52 		*gpio &= ~flag;
53 
54 	return 0;
55 }
56 
57 /*
58  * Back-channel sandbox-internal-only access to GPIO state
59  */
60 
sandbox_gpio_get_value(struct udevice * dev,unsigned offset)61 int sandbox_gpio_get_value(struct udevice *dev, unsigned offset)
62 {
63 	if (get_gpio_flag(dev, offset, GPIOF_OUTPUT))
64 		debug("sandbox_gpio: get_value on output gpio %u\n", offset);
65 	return get_gpio_flag(dev, offset, GPIOF_HIGH);
66 }
67 
sandbox_gpio_set_value(struct udevice * dev,unsigned offset,int value)68 int sandbox_gpio_set_value(struct udevice *dev, unsigned offset, int value)
69 {
70 	return set_gpio_flag(dev, offset, GPIOF_HIGH, value);
71 }
72 
sandbox_gpio_get_open_drain(struct udevice * dev,unsigned offset)73 int sandbox_gpio_get_open_drain(struct udevice *dev, unsigned offset)
74 {
75 	return get_gpio_flag(dev, offset, GPIOF_ODR);
76 }
77 
sandbox_gpio_set_open_drain(struct udevice * dev,unsigned offset,int value)78 int sandbox_gpio_set_open_drain(struct udevice *dev, unsigned offset, int value)
79 {
80 	return set_gpio_flag(dev, offset, GPIOF_ODR, value);
81 }
82 
sandbox_gpio_get_direction(struct udevice * dev,unsigned offset)83 int sandbox_gpio_get_direction(struct udevice *dev, unsigned offset)
84 {
85 	return get_gpio_flag(dev, offset, GPIOF_OUTPUT);
86 }
87 
sandbox_gpio_set_direction(struct udevice * dev,unsigned offset,int output)88 int sandbox_gpio_set_direction(struct udevice *dev, unsigned offset, int output)
89 {
90 	return set_gpio_flag(dev, offset, GPIOF_OUTPUT, output);
91 }
92 
93 /*
94  * These functions implement the public interface within U-Boot
95  */
96 
97 /* set GPIO port 'offset' as an input */
sb_gpio_direction_input(struct udevice * dev,unsigned offset)98 static int sb_gpio_direction_input(struct udevice *dev, unsigned offset)
99 {
100 	debug("%s: offset:%u\n", __func__, offset);
101 
102 	return sandbox_gpio_set_direction(dev, offset, 0);
103 }
104 
105 /* set GPIO port 'offset' as an output, with polarity 'value' */
sb_gpio_direction_output(struct udevice * dev,unsigned offset,int value)106 static int sb_gpio_direction_output(struct udevice *dev, unsigned offset,
107 				    int value)
108 {
109 	debug("%s: offset:%u, value = %d\n", __func__, offset, value);
110 
111 	return sandbox_gpio_set_direction(dev, offset, 1) |
112 		sandbox_gpio_set_value(dev, offset, value);
113 }
114 
115 /* read GPIO IN value of port 'offset' */
sb_gpio_get_value(struct udevice * dev,unsigned offset)116 static int sb_gpio_get_value(struct udevice *dev, unsigned offset)
117 {
118 	debug("%s: offset:%u\n", __func__, offset);
119 
120 	return sandbox_gpio_get_value(dev, offset);
121 }
122 
123 /* write GPIO OUT value to port 'offset' */
sb_gpio_set_value(struct udevice * dev,unsigned offset,int value)124 static int sb_gpio_set_value(struct udevice *dev, unsigned offset, int value)
125 {
126 	debug("%s: offset:%u, value = %d\n", __func__, offset, value);
127 
128 	if (!sandbox_gpio_get_direction(dev, offset)) {
129 		printf("sandbox_gpio: error: set_value on input gpio %u\n",
130 		       offset);
131 		return -1;
132 	}
133 
134 	return sandbox_gpio_set_value(dev, offset, value);
135 }
136 
137 /* read GPIO ODR value of port 'offset' */
sb_gpio_get_open_drain(struct udevice * dev,unsigned offset)138 static int sb_gpio_get_open_drain(struct udevice *dev, unsigned offset)
139 {
140 	debug("%s: offset:%u\n", __func__, offset);
141 
142 	return sandbox_gpio_get_open_drain(dev, offset);
143 }
144 
145 /* write GPIO ODR value to port 'offset' */
sb_gpio_set_open_drain(struct udevice * dev,unsigned offset,int value)146 static int sb_gpio_set_open_drain(struct udevice *dev, unsigned offset, int value)
147 {
148 	debug("%s: offset:%u, value = %d\n", __func__, offset, value);
149 
150 	if (!sandbox_gpio_get_direction(dev, offset)) {
151 		printf("sandbox_gpio: error: set_open_drain on input gpio %u\n",
152 		       offset);
153 		return -1;
154 	}
155 
156 	return sandbox_gpio_set_open_drain(dev, offset, value);
157 }
158 
sb_gpio_get_function(struct udevice * dev,unsigned offset)159 static int sb_gpio_get_function(struct udevice *dev, unsigned offset)
160 {
161 	if (get_gpio_flag(dev, offset, GPIOF_OUTPUT))
162 		return GPIOF_OUTPUT;
163 	return GPIOF_INPUT;
164 }
165 
sb_gpio_xlate(struct udevice * dev,struct gpio_desc * desc,struct ofnode_phandle_args * args)166 static int sb_gpio_xlate(struct udevice *dev, struct gpio_desc *desc,
167 			 struct ofnode_phandle_args *args)
168 {
169 	desc->offset = args->args[0];
170 	if (args->args_count < 2)
171 		return 0;
172 	if (args->args[1] & GPIO_ACTIVE_LOW)
173 		desc->flags |= GPIOD_ACTIVE_LOW;
174 	if (args->args[1] & 2)
175 		desc->flags |= GPIOD_IS_IN;
176 	if (args->args[1] & 4)
177 		desc->flags |= GPIOD_IS_OUT;
178 	if (args->args[1] & 8)
179 		desc->flags |= GPIOD_IS_OUT_ACTIVE;
180 
181 	return 0;
182 }
183 
184 static const struct dm_gpio_ops gpio_sandbox_ops = {
185 	.direction_input	= sb_gpio_direction_input,
186 	.direction_output	= sb_gpio_direction_output,
187 	.get_value		= sb_gpio_get_value,
188 	.set_value		= sb_gpio_set_value,
189 	.get_open_drain		= sb_gpio_get_open_drain,
190 	.set_open_drain		= sb_gpio_set_open_drain,
191 	.get_function		= sb_gpio_get_function,
192 	.xlate			= sb_gpio_xlate,
193 };
194 
sandbox_gpio_ofdata_to_platdata(struct udevice * dev)195 static int sandbox_gpio_ofdata_to_platdata(struct udevice *dev)
196 {
197 	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
198 
199 	uc_priv->gpio_count = dev_read_u32_default(dev, "sandbox,gpio-count",
200 						   0);
201 	uc_priv->bank_name = dev_read_string(dev, "gpio-bank-name");
202 
203 	return 0;
204 }
205 
gpio_sandbox_probe(struct udevice * dev)206 static int gpio_sandbox_probe(struct udevice *dev)
207 {
208 	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
209 
210 	if (!dev_of_valid(dev))
211 		/* Tell the uclass how many GPIOs we have */
212 		uc_priv->gpio_count = CONFIG_SANDBOX_GPIO_COUNT;
213 
214 	dev->priv = calloc(sizeof(struct gpio_state), uc_priv->gpio_count);
215 
216 	return 0;
217 }
218 
gpio_sandbox_remove(struct udevice * dev)219 static int gpio_sandbox_remove(struct udevice *dev)
220 {
221 	free(dev->priv);
222 
223 	return 0;
224 }
225 
226 static const struct udevice_id sandbox_gpio_ids[] = {
227 	{ .compatible = "sandbox,gpio" },
228 	{ }
229 };
230 
231 U_BOOT_DRIVER(gpio_sandbox) = {
232 	.name	= "gpio_sandbox",
233 	.id	= UCLASS_GPIO,
234 	.of_match = sandbox_gpio_ids,
235 	.ofdata_to_platdata = sandbox_gpio_ofdata_to_platdata,
236 	.probe	= gpio_sandbox_probe,
237 	.remove	= gpio_sandbox_remove,
238 	.ops	= &gpio_sandbox_ops,
239 };
240