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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 | // SPDX-License-Identifier: GPL-2.0 /* * Turris Mox Moxtet GPIO expander * * Copyright (C) 2018 Marek Behún <kabel@kernel.org> */ #include <linux/bitops.h> #include <linux/gpio/driver.h> #include <linux/moxtet.h> #include <linux/module.h> #define MOXTET_GPIO_NGPIOS 12 #define MOXTET_GPIO_INPUTS 4 struct moxtet_gpio_desc { u16 in_mask; u16 out_mask; }; static const struct moxtet_gpio_desc descs[] = { [TURRIS_MOX_MODULE_SFP] = { .in_mask = GENMASK(2, 0), .out_mask = GENMASK(5, 4), }, }; struct moxtet_gpio_chip { struct device *dev; struct gpio_chip gpio_chip; const struct moxtet_gpio_desc *desc; }; static int moxtet_gpio_get_value(struct gpio_chip *gc, unsigned int offset) { struct moxtet_gpio_chip *chip = gpiochip_get_data(gc); int ret; if (chip->desc->in_mask & BIT(offset)) { ret = moxtet_device_read(chip->dev); } else if (chip->desc->out_mask & BIT(offset)) { ret = moxtet_device_written(chip->dev); if (ret >= 0) ret <<= MOXTET_GPIO_INPUTS; } else { return -EINVAL; } if (ret < 0) return ret; return !!(ret & BIT(offset)); } static void moxtet_gpio_set_value(struct gpio_chip *gc, unsigned int offset, int val) { struct moxtet_gpio_chip *chip = gpiochip_get_data(gc); int state; state = moxtet_device_written(chip->dev); if (state < 0) return; offset -= MOXTET_GPIO_INPUTS; if (val) state |= BIT(offset); else state &= ~BIT(offset); moxtet_device_write(chip->dev, state); } static int moxtet_gpio_get_direction(struct gpio_chip *gc, unsigned int offset) { struct moxtet_gpio_chip *chip = gpiochip_get_data(gc); /* All lines are hard wired to be either input or output, not both. */ if (chip->desc->in_mask & BIT(offset)) return GPIO_LINE_DIRECTION_IN; else if (chip->desc->out_mask & BIT(offset)) return GPIO_LINE_DIRECTION_OUT; else return -EINVAL; } static int moxtet_gpio_direction_input(struct gpio_chip *gc, unsigned int offset) { struct moxtet_gpio_chip *chip = gpiochip_get_data(gc); if (chip->desc->in_mask & BIT(offset)) return 0; else if (chip->desc->out_mask & BIT(offset)) return -ENOTSUPP; else return -EINVAL; } static int moxtet_gpio_direction_output(struct gpio_chip *gc, unsigned int offset, int val) { struct moxtet_gpio_chip *chip = gpiochip_get_data(gc); if (chip->desc->out_mask & BIT(offset)) moxtet_gpio_set_value(gc, offset, val); else if (chip->desc->in_mask & BIT(offset)) return -ENOTSUPP; else return -EINVAL; return 0; } static int moxtet_gpio_probe(struct device *dev) { struct moxtet_gpio_chip *chip; struct device_node *nc = dev->of_node; int id; id = to_moxtet_device(dev)->id; if (id >= ARRAY_SIZE(descs)) { dev_err(dev, "%pOF Moxtet device id 0x%x is not supported by gpio-moxtet driver\n", nc, id); return -ENOTSUPP; } chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL); if (!chip) return -ENOMEM; chip->dev = dev; chip->gpio_chip.parent = dev; chip->desc = &descs[id]; dev_set_drvdata(dev, chip); chip->gpio_chip.label = dev_name(dev); chip->gpio_chip.get_direction = moxtet_gpio_get_direction; chip->gpio_chip.direction_input = moxtet_gpio_direction_input; chip->gpio_chip.direction_output = moxtet_gpio_direction_output; chip->gpio_chip.get = moxtet_gpio_get_value; chip->gpio_chip.set = moxtet_gpio_set_value; chip->gpio_chip.base = -1; chip->gpio_chip.ngpio = MOXTET_GPIO_NGPIOS; chip->gpio_chip.can_sleep = true; chip->gpio_chip.owner = THIS_MODULE; return devm_gpiochip_add_data(dev, &chip->gpio_chip, chip); } static const struct of_device_id moxtet_gpio_dt_ids[] = { { .compatible = "cznic,moxtet-gpio", }, {}, }; MODULE_DEVICE_TABLE(of, moxtet_gpio_dt_ids); static const enum turris_mox_module_id moxtet_gpio_module_table[] = { TURRIS_MOX_MODULE_SFP, 0, }; static struct moxtet_driver moxtet_gpio_driver = { .driver = { .name = "moxtet-gpio", .of_match_table = moxtet_gpio_dt_ids, .probe = moxtet_gpio_probe, }, .id_table = moxtet_gpio_module_table, }; module_moxtet_driver(moxtet_gpio_driver); MODULE_AUTHOR("Marek Behun <kabel@kernel.org>"); MODULE_DESCRIPTION("Turris Mox Moxtet GPIO expander"); MODULE_LICENSE("GPL v2"); |