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 12 DECLARE_GLOBAL_DATA_PTR; 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 18 struct gpio_state { 19 const char *label; /* label given by requester */ 20 u8 flags; /* flags (GPIOF_...) */ 21 }; 22 23 /* Access routines for GPIO state */ 24 static u8 *get_gpio_flags(struct udevice *dev, unsigned offset) 25 { 26 struct gpio_dev_priv *uc_priv = dev->uclass_priv; 27 struct gpio_state *state = dev_get_priv(dev); 28 29 if (offset >= uc_priv->gpio_count) { 30 static u8 invalid_flags; 31 printf("sandbox_gpio: error: invalid gpio %u\n", offset); 32 return &invalid_flags; 33 } 34 35 return &state[offset].flags; 36 } 37 38 static int get_gpio_flag(struct udevice *dev, unsigned offset, int flag) 39 { 40 return (*get_gpio_flags(dev, offset) & flag) != 0; 41 } 42 43 static int set_gpio_flag(struct udevice *dev, unsigned offset, int flag, 44 int value) 45 { 46 u8 *gpio = get_gpio_flags(dev, offset); 47 48 if (value) 49 *gpio |= flag; 50 else 51 *gpio &= ~flag; 52 53 return 0; 54 } 55 56 /* 57 * Back-channel sandbox-internal-only access to GPIO state 58 */ 59 60 int sandbox_gpio_get_value(struct udevice *dev, unsigned offset) 61 { 62 if (get_gpio_flag(dev, offset, GPIOF_OUTPUT)) 63 debug("sandbox_gpio: get_value on output gpio %u\n", offset); 64 return get_gpio_flag(dev, offset, GPIOF_HIGH); 65 } 66 67 int sandbox_gpio_set_value(struct udevice *dev, unsigned offset, int value) 68 { 69 return set_gpio_flag(dev, offset, GPIOF_HIGH, value); 70 } 71 72 int sandbox_gpio_get_direction(struct udevice *dev, unsigned offset) 73 { 74 return get_gpio_flag(dev, offset, GPIOF_OUTPUT); 75 } 76 77 int sandbox_gpio_set_direction(struct udevice *dev, unsigned offset, int output) 78 { 79 return set_gpio_flag(dev, offset, GPIOF_OUTPUT, output); 80 } 81 82 /* 83 * These functions implement the public interface within U-Boot 84 */ 85 86 /* set GPIO port 'offset' as an input */ 87 static int sb_gpio_direction_input(struct udevice *dev, unsigned offset) 88 { 89 debug("%s: offset:%u\n", __func__, offset); 90 91 return sandbox_gpio_set_direction(dev, offset, 0); 92 } 93 94 /* set GPIO port 'offset' as an output, with polarity 'value' */ 95 static int sb_gpio_direction_output(struct udevice *dev, unsigned offset, 96 int value) 97 { 98 debug("%s: offset:%u, value = %d\n", __func__, offset, value); 99 100 return sandbox_gpio_set_direction(dev, offset, 1) | 101 sandbox_gpio_set_value(dev, offset, value); 102 } 103 104 /* read GPIO IN value of port 'offset' */ 105 static int sb_gpio_get_value(struct udevice *dev, unsigned offset) 106 { 107 debug("%s: offset:%u\n", __func__, offset); 108 109 return sandbox_gpio_get_value(dev, offset); 110 } 111 112 /* write GPIO OUT value to port 'offset' */ 113 static int sb_gpio_set_value(struct udevice *dev, unsigned offset, int value) 114 { 115 debug("%s: offset:%u, value = %d\n", __func__, offset, value); 116 117 if (!sandbox_gpio_get_direction(dev, offset)) { 118 printf("sandbox_gpio: error: set_value on input gpio %u\n", 119 offset); 120 return -1; 121 } 122 123 return sandbox_gpio_set_value(dev, offset, value); 124 } 125 126 static int sb_gpio_get_function(struct udevice *dev, unsigned offset) 127 { 128 if (get_gpio_flag(dev, offset, GPIOF_OUTPUT)) 129 return GPIOF_OUTPUT; 130 return GPIOF_INPUT; 131 } 132 133 static const struct dm_gpio_ops gpio_sandbox_ops = { 134 .direction_input = sb_gpio_direction_input, 135 .direction_output = sb_gpio_direction_output, 136 .get_value = sb_gpio_get_value, 137 .set_value = sb_gpio_set_value, 138 .get_function = sb_gpio_get_function, 139 }; 140 141 static int sandbox_gpio_ofdata_to_platdata(struct udevice *dev) 142 { 143 struct gpio_dev_priv *uc_priv = dev->uclass_priv; 144 145 uc_priv->gpio_count = fdtdec_get_int(gd->fdt_blob, dev->of_offset, 146 "num-gpios", 0); 147 uc_priv->bank_name = fdt_getprop(gd->fdt_blob, dev->of_offset, 148 "gpio-bank-name", NULL); 149 150 return 0; 151 } 152 153 static int gpio_sandbox_probe(struct udevice *dev) 154 { 155 struct gpio_dev_priv *uc_priv = dev->uclass_priv; 156 157 if (dev->of_offset == -1) { 158 /* Tell the uclass how many GPIOs we have */ 159 uc_priv->gpio_count = CONFIG_SANDBOX_GPIO_COUNT; 160 } 161 162 dev->priv = calloc(sizeof(struct gpio_state), uc_priv->gpio_count); 163 164 return 0; 165 } 166 167 static int gpio_sandbox_remove(struct udevice *dev) 168 { 169 free(dev->priv); 170 171 return 0; 172 } 173 174 static const struct udevice_id sandbox_gpio_ids[] = { 175 { .compatible = "sandbox,gpio" }, 176 { } 177 }; 178 179 U_BOOT_DRIVER(gpio_sandbox) = { 180 .name = "gpio_sandbox", 181 .id = UCLASS_GPIO, 182 .of_match = sandbox_gpio_ids, 183 .ofdata_to_platdata = sandbox_gpio_ofdata_to_platdata, 184 .probe = gpio_sandbox_probe, 185 .remove = gpio_sandbox_remove, 186 .ops = &gpio_sandbox_ops, 187 }; 188