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1// SPDX-License-Identifier: GPL-2.0+2/*3 * Copyright (C) 2019 Bootlin4 * Author: Paul Kocialkowski <paul.kocialkowski@bootlin.com>5 */6 7#include <linux/err.h>8#include <linux/gpio/driver.h>9#include <linux/module.h>10#include <linux/of.h>11#include <linux/of_address.h>12#include <linux/platform_device.h>13#include <linux/regmap.h>14#include <linux/mfd/syscon.h>15 16#define LOGICVC_CTRL_REG 0x4017#define LOGICVC_CTRL_GPIO_SHIFT 1118#define LOGICVC_CTRL_GPIO_BITS 519 20#define LOGICVC_POWER_CTRL_REG 0x7821#define LOGICVC_POWER_CTRL_GPIO_SHIFT 022#define LOGICVC_POWER_CTRL_GPIO_BITS 423 24struct logicvc_gpio {25 struct gpio_chip chip;26 struct regmap *regmap;27};28 29static void logicvc_gpio_offset(struct logicvc_gpio *logicvc, unsigned offset,30 unsigned int *reg, unsigned int *bit)31{32 if (offset >= LOGICVC_CTRL_GPIO_BITS) {33 *reg = LOGICVC_POWER_CTRL_REG;34 35 /* To the (virtual) power ctrl offset. */36 offset -= LOGICVC_CTRL_GPIO_BITS;37 /* To the actual bit offset in reg. */38 offset += LOGICVC_POWER_CTRL_GPIO_SHIFT;39 } else {40 *reg = LOGICVC_CTRL_REG;41 42 /* To the actual bit offset in reg. */43 offset += LOGICVC_CTRL_GPIO_SHIFT;44 }45 46 *bit = BIT(offset);47}48 49static int logicvc_gpio_get(struct gpio_chip *chip, unsigned offset)50{51 struct logicvc_gpio *logicvc = gpiochip_get_data(chip);52 unsigned int reg, bit, value;53 int ret;54 55 logicvc_gpio_offset(logicvc, offset, ®, &bit);56 57 ret = regmap_read(logicvc->regmap, reg, &value);58 if (ret)59 return ret;60 61 return !!(value & bit);62}63 64static void logicvc_gpio_set(struct gpio_chip *chip, unsigned offset, int value)65{66 struct logicvc_gpio *logicvc = gpiochip_get_data(chip);67 unsigned int reg, bit;68 69 logicvc_gpio_offset(logicvc, offset, ®, &bit);70 71 regmap_update_bits(logicvc->regmap, reg, bit, value ? bit : 0);72}73 74static int logicvc_gpio_direction_output(struct gpio_chip *chip,75 unsigned offset, int value)76{77 /* Pins are always configured as output, so just set the value. */78 logicvc_gpio_set(chip, offset, value);79 80 return 0;81}82 83static struct regmap_config logicvc_gpio_regmap_config = {84 .reg_bits = 32,85 .val_bits = 32,86 .reg_stride = 4,87 .name = "logicvc-gpio",88};89 90static int logicvc_gpio_probe(struct platform_device *pdev)91{92 struct device *dev = &pdev->dev;93 struct device_node *of_node = dev->of_node;94 struct logicvc_gpio *logicvc;95 int ret;96 97 logicvc = devm_kzalloc(dev, sizeof(*logicvc), GFP_KERNEL);98 if (!logicvc)99 return -ENOMEM;100 101 /* Try to get regmap from parent first. */102 logicvc->regmap = syscon_node_to_regmap(of_node->parent);103 104 /* Grab our own regmap if that fails. */105 if (IS_ERR(logicvc->regmap)) {106 struct resource res;107 void __iomem *base;108 109 ret = of_address_to_resource(of_node, 0, &res);110 if (ret) {111 dev_err(dev, "Failed to get resource from address\n");112 return ret;113 }114 115 base = devm_ioremap_resource(dev, &res);116 if (IS_ERR(base))117 return PTR_ERR(base);118 119 logicvc_gpio_regmap_config.max_register = resource_size(&res) -120 logicvc_gpio_regmap_config.reg_stride;121 122 logicvc->regmap =123 devm_regmap_init_mmio(dev, base,124 &logicvc_gpio_regmap_config);125 if (IS_ERR(logicvc->regmap)) {126 dev_err(dev, "Failed to create regmap for I/O\n");127 return PTR_ERR(logicvc->regmap);128 }129 }130 131 logicvc->chip.parent = dev;132 logicvc->chip.owner = THIS_MODULE;133 logicvc->chip.label = dev_name(dev);134 logicvc->chip.base = -1;135 logicvc->chip.ngpio = LOGICVC_CTRL_GPIO_BITS +136 LOGICVC_POWER_CTRL_GPIO_BITS;137 logicvc->chip.get = logicvc_gpio_get;138 logicvc->chip.set = logicvc_gpio_set;139 logicvc->chip.direction_output = logicvc_gpio_direction_output;140 141 return devm_gpiochip_add_data(dev, &logicvc->chip, logicvc);142}143 144static const struct of_device_id logicivc_gpio_of_table[] = {145 {146 .compatible = "xylon,logicvc-3.02.a-gpio",147 },148 { }149};150 151MODULE_DEVICE_TABLE(of, logicivc_gpio_of_table);152 153static struct platform_driver logicvc_gpio_driver = {154 .driver = {155 .name = "gpio-logicvc",156 .of_match_table = logicivc_gpio_of_table,157 },158 .probe = logicvc_gpio_probe,159};160 161module_platform_driver(logicvc_gpio_driver);162 163MODULE_AUTHOR("Paul Kocialkowski <paul.kocialkowski@bootlin.com>");164MODULE_DESCRIPTION("Xylon LogiCVC GPIO driver");165MODULE_LICENSE("GPL");166