1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * GPIO library for the ACCES IDIO-16 family 4 * Copyright (C) 2022 William Breathitt Gray 5 */ 6 7 #define DEFAULT_SYMBOL_NAMESPACE "GPIO_IDIO_16" 8 9 #include <linux/bits.h> 10 #include <linux/device.h> 11 #include <linux/err.h> 12 #include <linux/export.h> 13 #include <linux/gpio/regmap.h> 14 #include <linux/module.h> 15 #include <linux/regmap.h> 16 #include <linux/types.h> 17 18 #include "gpio-idio-16.h" 19 20 #define IDIO_16_DAT_BASE 0x0 21 #define IDIO_16_OUT_BASE IDIO_16_DAT_BASE 22 #define IDIO_16_IN_BASE (IDIO_16_DAT_BASE + 1) 23 #define IDIO_16_CLEAR_INTERRUPT 0x1 24 #define IDIO_16_ENABLE_IRQ 0x2 25 #define IDIO_16_DEACTIVATE_INPUT_FILTERS 0x3 26 #define IDIO_16_DISABLE_IRQ IDIO_16_ENABLE_IRQ 27 #define IDIO_16_INTERRUPT_STATUS 0x6 28 29 #define IDIO_16_NGPIO 32 30 #define IDIO_16_NGPIO_PER_REG 8 31 #define IDIO_16_REG_STRIDE 4 32 33 struct idio_16_data { 34 struct regmap *map; 35 unsigned int irq_mask; 36 }; 37 38 static int idio_16_handle_mask_sync(const int index, const unsigned int mask_buf_def, 39 const unsigned int mask_buf, void *const irq_drv_data) 40 { 41 struct idio_16_data *const data = irq_drv_data; 42 const unsigned int prev_mask = data->irq_mask; 43 int err; 44 unsigned int val; 45 46 /* exit early if no change since the previous mask */ 47 if (mask_buf == prev_mask) 48 return 0; 49 50 /* remember the current mask for the next mask sync */ 51 data->irq_mask = mask_buf; 52 53 /* if all previously masked, enable interrupts when unmasking */ 54 if (prev_mask == mask_buf_def) { 55 err = regmap_write(data->map, IDIO_16_CLEAR_INTERRUPT, 0x00); 56 if (err) 57 return err; 58 return regmap_read(data->map, IDIO_16_ENABLE_IRQ, &val); 59 } 60 61 /* if all are currently masked, disable interrupts */ 62 if (mask_buf == mask_buf_def) 63 return regmap_write(data->map, IDIO_16_DISABLE_IRQ, 0x00); 64 65 return 0; 66 } 67 68 static int idio_16_reg_mask_xlate(struct gpio_regmap *const gpio, const unsigned int base, 69 const unsigned int offset, unsigned int *const reg, 70 unsigned int *const mask) 71 { 72 unsigned int stride; 73 74 /* Input lines start at GPIO 16 */ 75 if (offset < 16) { 76 stride = offset / IDIO_16_NGPIO_PER_REG; 77 *reg = IDIO_16_OUT_BASE + stride * IDIO_16_REG_STRIDE; 78 } else { 79 stride = (offset - 16) / IDIO_16_NGPIO_PER_REG; 80 *reg = IDIO_16_IN_BASE + stride * IDIO_16_REG_STRIDE; 81 } 82 83 *mask = BIT(offset % IDIO_16_NGPIO_PER_REG); 84 85 return 0; 86 } 87 88 static const char *idio_16_names[IDIO_16_NGPIO] = { 89 "OUT0", "OUT1", "OUT2", "OUT3", "OUT4", "OUT5", "OUT6", "OUT7", 90 "OUT8", "OUT9", "OUT10", "OUT11", "OUT12", "OUT13", "OUT14", "OUT15", 91 "IIN0", "IIN1", "IIN2", "IIN3", "IIN4", "IIN5", "IIN6", "IIN7", 92 "IIN8", "IIN9", "IIN10", "IIN11", "IIN12", "IIN13", "IIN14", "IIN15", 93 }; 94 95 /** 96 * devm_idio_16_regmap_register - Register an IDIO-16 GPIO device 97 * @dev: device that is registering this IDIO-16 GPIO device 98 * @config: configuration for idio_16_regmap_config 99 * 100 * Registers an IDIO-16 GPIO device. Returns 0 on success and negative error number on failure. 101 */ 102 int devm_idio_16_regmap_register(struct device *const dev, 103 const struct idio_16_regmap_config *const config) 104 { 105 struct gpio_regmap_config gpio_config = {}; 106 int err; 107 struct idio_16_data *data; 108 struct regmap_irq_chip *chip; 109 struct regmap_irq_chip_data *chip_data; 110 111 if (!config->parent) 112 return -EINVAL; 113 114 if (!config->map) 115 return -EINVAL; 116 117 if (!config->regmap_irqs) 118 return -EINVAL; 119 120 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); 121 if (!data) 122 return -ENOMEM; 123 data->map = config->map; 124 125 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL); 126 if (!chip) 127 return -ENOMEM; 128 129 chip->name = dev_name(dev); 130 chip->status_base = IDIO_16_INTERRUPT_STATUS; 131 chip->mask_base = IDIO_16_ENABLE_IRQ; 132 chip->ack_base = IDIO_16_CLEAR_INTERRUPT; 133 chip->no_status = config->no_status; 134 chip->num_regs = 1; 135 chip->irqs = config->regmap_irqs; 136 chip->num_irqs = config->num_regmap_irqs; 137 chip->handle_mask_sync = idio_16_handle_mask_sync; 138 chip->irq_drv_data = data; 139 140 /* Disable IRQ to prevent spurious interrupts before we're ready */ 141 err = regmap_write(data->map, IDIO_16_DISABLE_IRQ, 0x00); 142 if (err) 143 return err; 144 145 err = devm_regmap_add_irq_chip(dev, data->map, config->irq, 0, 0, chip, &chip_data); 146 if (err) 147 return dev_err_probe(dev, err, "IRQ registration failed\n"); 148 149 if (config->filters) { 150 /* Deactivate input filters */ 151 err = regmap_write(data->map, IDIO_16_DEACTIVATE_INPUT_FILTERS, 0x00); 152 if (err) 153 return err; 154 } 155 156 gpio_config.parent = config->parent; 157 gpio_config.regmap = data->map; 158 gpio_config.ngpio = IDIO_16_NGPIO; 159 gpio_config.names = idio_16_names; 160 gpio_config.reg_dat_base = GPIO_REGMAP_ADDR(IDIO_16_DAT_BASE); 161 gpio_config.reg_set_base = GPIO_REGMAP_ADDR(IDIO_16_DAT_BASE); 162 gpio_config.ngpio_per_reg = IDIO_16_NGPIO_PER_REG; 163 gpio_config.reg_stride = IDIO_16_REG_STRIDE; 164 gpio_config.irq_domain = regmap_irq_get_domain(chip_data); 165 gpio_config.reg_mask_xlate = idio_16_reg_mask_xlate; 166 167 return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(dev, &gpio_config)); 168 } 169 EXPORT_SYMBOL_GPL(devm_idio_16_regmap_register); 170 171 MODULE_AUTHOR("William Breathitt Gray"); 172 MODULE_DESCRIPTION("ACCES IDIO-16 GPIO Library"); 173 MODULE_LICENSE("GPL"); 174