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