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 */ 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 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 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 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 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 73 int sandbox_gpio_get_open_drain(struct udevice *dev, unsigned offset) 74 { 75 return get_gpio_flag(dev, offset, GPIOF_ODR); 76 } 77 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 83 int sandbox_gpio_get_direction(struct udevice *dev, unsigned offset) 84 { 85 return get_gpio_flag(dev, offset, GPIOF_OUTPUT); 86 } 87 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 */ 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' */ 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' */ 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' */ 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' */ 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' */ 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 } 158 159 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 } 165 166 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 }; 194 195 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 } 205 206 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 } 218 219 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 }; 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