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 #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_16 18 19 #define IDIO_16_DAT_BASE 0x0 20 #define IDIO_16_OUT_BASE IDIO_16_DAT_BASE 21 #define IDIO_16_IN_BASE (IDIO_16_DAT_BASE + 1) 22 #define IDIO_16_CLEAR_INTERRUPT 0x1 23 #define IDIO_16_ENABLE_IRQ 0x2 24 #define IDIO_16_DEACTIVATE_INPUT_FILTERS 0x3 25 #define IDIO_16_DISABLE_IRQ IDIO_16_ENABLE_IRQ 26 #define IDIO_16_INTERRUPT_STATUS 0x6 27 28 #define IDIO_16_NGPIO 32 29 #define IDIO_16_NGPIO_PER_REG 8 30 #define IDIO_16_REG_STRIDE 4 31 32 struct idio_16_data { 33 struct regmap *map; 34 unsigned int irq_mask; 35 }; 36 37 static 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 67 static 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 87 static 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 device 96 * @dev: device that is registering this IDIO-16 GPIO device 97 * @config: configuration for idio_16_regmap_config 98 * 99 * Registers an IDIO-16 GPIO device. Returns 0 on success and negative error number on failure. 100 */ 101 int 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 } 168 EXPORT_SYMBOL_GPL(devm_idio_16_regmap_register); 169 170 MODULE_AUTHOR("William Breathitt Gray"); 171 MODULE_DESCRIPTION("ACCES IDIO-16 GPIO Library"); 172 MODULE_LICENSE("GPL"); 173