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1// SPDX-License-Identifier: GPL-2.02/*3 * GPIO library for the ACCES IDIO-16 family4 * Copyright (C) 2022 William Breathitt Gray5 */6#include <linux/bits.h>7#include <linux/device.h>8#include <linux/err.h>9#include <linux/export.h>10#include <linux/gpio/regmap.h>11#include <linux/module.h>12#include <linux/regmap.h>13#include <linux/types.h>14 15#include "gpio-idio-16.h"16 17#define DEFAULT_SYMBOL_NAMESPACE GPIO_IDIO_1618 19#define IDIO_16_DAT_BASE 0x020#define IDIO_16_OUT_BASE IDIO_16_DAT_BASE21#define IDIO_16_IN_BASE (IDIO_16_DAT_BASE + 1)22#define IDIO_16_CLEAR_INTERRUPT 0x123#define IDIO_16_ENABLE_IRQ 0x224#define IDIO_16_DEACTIVATE_INPUT_FILTERS 0x325#define IDIO_16_DISABLE_IRQ IDIO_16_ENABLE_IRQ26#define IDIO_16_INTERRUPT_STATUS 0x627 28#define IDIO_16_NGPIO 3229#define IDIO_16_NGPIO_PER_REG 830#define IDIO_16_REG_STRIDE 431 32struct idio_16_data {33 struct regmap *map;34 unsigned int irq_mask;35};36 37static int idio_16_handle_mask_sync(const int index, const unsigned int mask_buf_def,38 const unsigned int mask_buf, void *const irq_drv_data)39{40 struct idio_16_data *const data = irq_drv_data;41 const unsigned int prev_mask = data->irq_mask;42 int err;43 unsigned int val;44 45 /* exit early if no change since the previous mask */46 if (mask_buf == prev_mask)47 return 0;48 49 /* remember the current mask for the next mask sync */50 data->irq_mask = mask_buf;51 52 /* if all previously masked, enable interrupts when unmasking */53 if (prev_mask == mask_buf_def) {54 err = regmap_write(data->map, IDIO_16_CLEAR_INTERRUPT, 0x00);55 if (err)56 return err;57 return regmap_read(data->map, IDIO_16_ENABLE_IRQ, &val);58 }59 60 /* if all are currently masked, disable interrupts */61 if (mask_buf == mask_buf_def)62 return regmap_write(data->map, IDIO_16_DISABLE_IRQ, 0x00);63 64 return 0;65}66 67static int idio_16_reg_mask_xlate(struct gpio_regmap *const gpio, const unsigned int base,68 const unsigned int offset, unsigned int *const reg,69 unsigned int *const mask)70{71 unsigned int stride;72 73 /* Input lines start at GPIO 16 */74 if (offset < 16) {75 stride = offset / IDIO_16_NGPIO_PER_REG;76 *reg = IDIO_16_OUT_BASE + stride * IDIO_16_REG_STRIDE;77 } else {78 stride = (offset - 16) / IDIO_16_NGPIO_PER_REG;79 *reg = IDIO_16_IN_BASE + stride * IDIO_16_REG_STRIDE;80 }81 82 *mask = BIT(offset % IDIO_16_NGPIO_PER_REG);83 84 return 0;85}86 87static const char *idio_16_names[IDIO_16_NGPIO] = {88 "OUT0", "OUT1", "OUT2", "OUT3", "OUT4", "OUT5", "OUT6", "OUT7",89 "OUT8", "OUT9", "OUT10", "OUT11", "OUT12", "OUT13", "OUT14", "OUT15",90 "IIN0", "IIN1", "IIN2", "IIN3", "IIN4", "IIN5", "IIN6", "IIN7",91 "IIN8", "IIN9", "IIN10", "IIN11", "IIN12", "IIN13", "IIN14", "IIN15",92};93 94/**95 * devm_idio_16_regmap_register - Register an IDIO-16 GPIO device96 * @dev: device that is registering this IDIO-16 GPIO device97 * @config: configuration for idio_16_regmap_config98 *99 * Registers an IDIO-16 GPIO device. Returns 0 on success and negative error number on failure.100 */101int devm_idio_16_regmap_register(struct device *const dev,102 const struct idio_16_regmap_config *const config)103{104 struct gpio_regmap_config gpio_config = {};105 int err;106 struct idio_16_data *data;107 struct regmap_irq_chip *chip;108 struct regmap_irq_chip_data *chip_data;109 110 if (!config->parent)111 return -EINVAL;112 113 if (!config->map)114 return -EINVAL;115 116 if (!config->regmap_irqs)117 return -EINVAL;118 119 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);120 if (!data)121 return -ENOMEM;122 data->map = config->map;123 124 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);125 if (!chip)126 return -ENOMEM;127 128 chip->name = dev_name(dev);129 chip->status_base = IDIO_16_INTERRUPT_STATUS;130 chip->mask_base = IDIO_16_ENABLE_IRQ;131 chip->ack_base = IDIO_16_CLEAR_INTERRUPT;132 chip->no_status = config->no_status;133 chip->num_regs = 1;134 chip->irqs = config->regmap_irqs;135 chip->num_irqs = config->num_regmap_irqs;136 chip->handle_mask_sync = idio_16_handle_mask_sync;137 chip->irq_drv_data = data;138 139 /* Disable IRQ to prevent spurious interrupts before we're ready */140 err = regmap_write(data->map, IDIO_16_DISABLE_IRQ, 0x00);141 if (err)142 return err;143 144 err = devm_regmap_add_irq_chip(dev, data->map, config->irq, 0, 0, chip, &chip_data);145 if (err)146 return dev_err_probe(dev, err, "IRQ registration failed\n");147 148 if (config->filters) {149 /* Deactivate input filters */150 err = regmap_write(data->map, IDIO_16_DEACTIVATE_INPUT_FILTERS, 0x00);151 if (err)152 return err;153 }154 155 gpio_config.parent = config->parent;156 gpio_config.regmap = data->map;157 gpio_config.ngpio = IDIO_16_NGPIO;158 gpio_config.names = idio_16_names;159 gpio_config.reg_dat_base = GPIO_REGMAP_ADDR(IDIO_16_DAT_BASE);160 gpio_config.reg_set_base = GPIO_REGMAP_ADDR(IDIO_16_DAT_BASE);161 gpio_config.ngpio_per_reg = IDIO_16_NGPIO_PER_REG;162 gpio_config.reg_stride = IDIO_16_REG_STRIDE;163 gpio_config.irq_domain = regmap_irq_get_domain(chip_data);164 gpio_config.reg_mask_xlate = idio_16_reg_mask_xlate;165 166 return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(dev, &gpio_config));167}168EXPORT_SYMBOL_GPL(devm_idio_16_regmap_register);169 170MODULE_AUTHOR("William Breathitt Gray");171MODULE_DESCRIPTION("ACCES IDIO-16 GPIO Library");172MODULE_LICENSE("GPL");173