1 /* 2 * Copyright (c) 2011 The Chromium OS Authors. 3 * SPDX-License-Identifier: GPL-2.0+ 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 <dt-bindings/gpio/gpio.h> 12 13 DECLARE_GLOBAL_DATA_PTR; 14 15 /* Flags for each GPIO */ 16 #define GPIOF_OUTPUT (1 << 0) /* Currently set as an output */ 17 #define GPIOF_HIGH (1 << 1) /* Currently set high */ 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_direction(struct udevice *dev, unsigned offset) 74 { 75 return get_gpio_flag(dev, offset, GPIOF_OUTPUT); 76 } 77 78 int sandbox_gpio_set_direction(struct udevice *dev, unsigned offset, int output) 79 { 80 return set_gpio_flag(dev, offset, GPIOF_OUTPUT, output); 81 } 82 83 /* 84 * These functions implement the public interface within U-Boot 85 */ 86 87 /* set GPIO port 'offset' as an input */ 88 static int sb_gpio_direction_input(struct udevice *dev, unsigned offset) 89 { 90 debug("%s: offset:%u\n", __func__, offset); 91 92 return sandbox_gpio_set_direction(dev, offset, 0); 93 } 94 95 /* set GPIO port 'offset' as an output, with polarity 'value' */ 96 static int sb_gpio_direction_output(struct udevice *dev, unsigned offset, 97 int value) 98 { 99 debug("%s: offset:%u, value = %d\n", __func__, offset, value); 100 101 return sandbox_gpio_set_direction(dev, offset, 1) | 102 sandbox_gpio_set_value(dev, offset, value); 103 } 104 105 /* read GPIO IN value of port 'offset' */ 106 static int sb_gpio_get_value(struct udevice *dev, unsigned offset) 107 { 108 debug("%s: offset:%u\n", __func__, offset); 109 110 return sandbox_gpio_get_value(dev, offset); 111 } 112 113 /* write GPIO OUT value to port 'offset' */ 114 static int sb_gpio_set_value(struct udevice *dev, unsigned offset, int value) 115 { 116 debug("%s: offset:%u, value = %d\n", __func__, offset, value); 117 118 if (!sandbox_gpio_get_direction(dev, offset)) { 119 printf("sandbox_gpio: error: set_value on input gpio %u\n", 120 offset); 121 return -1; 122 } 123 124 return sandbox_gpio_set_value(dev, offset, value); 125 } 126 127 static int sb_gpio_get_function(struct udevice *dev, unsigned offset) 128 { 129 if (get_gpio_flag(dev, offset, GPIOF_OUTPUT)) 130 return GPIOF_OUTPUT; 131 return GPIOF_INPUT; 132 } 133 134 static int sb_gpio_xlate(struct udevice *dev, struct gpio_desc *desc, 135 struct fdtdec_phandle_args *args) 136 { 137 desc->offset = args->args[0]; 138 if (args->args_count < 2) 139 return 0; 140 if (args->args[1] & GPIO_ACTIVE_LOW) 141 desc->flags |= GPIOD_ACTIVE_LOW; 142 if (args->args[1] & 2) 143 desc->flags |= GPIOD_IS_IN; 144 if (args->args[1] & 4) 145 desc->flags |= GPIOD_IS_OUT; 146 if (args->args[1] & 8) 147 desc->flags |= GPIOD_IS_OUT_ACTIVE; 148 149 return 0; 150 } 151 152 static const struct dm_gpio_ops gpio_sandbox_ops = { 153 .direction_input = sb_gpio_direction_input, 154 .direction_output = sb_gpio_direction_output, 155 .get_value = sb_gpio_get_value, 156 .set_value = sb_gpio_set_value, 157 .get_function = sb_gpio_get_function, 158 .xlate = sb_gpio_xlate, 159 }; 160 161 static int sandbox_gpio_ofdata_to_platdata(struct udevice *dev) 162 { 163 struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev); 164 165 uc_priv->gpio_count = fdtdec_get_int(gd->fdt_blob, dev->of_offset, 166 "num-gpios", 0); 167 uc_priv->bank_name = fdt_getprop(gd->fdt_blob, dev->of_offset, 168 "gpio-bank-name", NULL); 169 170 return 0; 171 } 172 173 static int gpio_sandbox_probe(struct udevice *dev) 174 { 175 struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev); 176 177 if (dev->of_offset == -1) { 178 /* Tell the uclass how many GPIOs we have */ 179 uc_priv->gpio_count = CONFIG_SANDBOX_GPIO_COUNT; 180 } 181 182 dev->priv = calloc(sizeof(struct gpio_state), uc_priv->gpio_count); 183 184 return 0; 185 } 186 187 static int gpio_sandbox_remove(struct udevice *dev) 188 { 189 free(dev->priv); 190 191 return 0; 192 } 193 194 static const struct udevice_id sandbox_gpio_ids[] = { 195 { .compatible = "sandbox,gpio" }, 196 { } 197 }; 198 199 U_BOOT_DRIVER(gpio_sandbox) = { 200 .name = "gpio_sandbox", 201 .id = UCLASS_GPIO, 202 .of_match = sandbox_gpio_ids, 203 .ofdata_to_platdata = sandbox_gpio_ofdata_to_platdata, 204 .probe = gpio_sandbox_probe, 205 .remove = gpio_sandbox_remove, 206 .ops = &gpio_sandbox_ops, 207 }; 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