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/bitmap.h> 10 #include <linux/bits.h> 11 #include <linux/device.h> 12 #include <linux/err.h> 13 #include <linux/export.h> 14 #include <linux/gpio/regmap.h> 15 #include <linux/module.h> 16 #include <linux/regmap.h> 17 #include <linux/types.h> 18 19 #include "gpio-idio-16.h" 20 21 #define IDIO_16_DAT_BASE 0x0 22 #define IDIO_16_OUT_BASE IDIO_16_DAT_BASE 23 #define IDIO_16_IN_BASE (IDIO_16_DAT_BASE + 1) 24 #define IDIO_16_CLEAR_INTERRUPT 0x1 25 #define IDIO_16_ENABLE_IRQ 0x2 26 #define IDIO_16_DEACTIVATE_INPUT_FILTERS 0x3 27 #define IDIO_16_DISABLE_IRQ IDIO_16_ENABLE_IRQ 28 #define IDIO_16_INTERRUPT_STATUS 0x6 29 30 #define IDIO_16_NGPIO 32 31 #define IDIO_16_NGPIO_PER_REG 8 32 #define IDIO_16_REG_STRIDE 4 33 34 struct idio_16_data { 35 struct regmap *map; 36 unsigned int irq_mask; 37 }; 38 39 static int idio_16_handle_mask_sync(const int index, const unsigned int mask_buf_def, 40 const unsigned int mask_buf, void *const irq_drv_data) 41 { 42 struct idio_16_data *const data = irq_drv_data; 43 const unsigned int prev_mask = data->irq_mask; 44 int err; 45 unsigned int val; 46 47 /* exit early if no change since the previous mask */ 48 if (mask_buf == prev_mask) 49 return 0; 50 51 /* remember the current mask for the next mask sync */ 52 data->irq_mask = mask_buf; 53 54 /* if all previously masked, enable interrupts when unmasking */ 55 if (prev_mask == mask_buf_def) { 56 err = regmap_write(data->map, IDIO_16_CLEAR_INTERRUPT, 0x00); 57 if (err) 58 return err; 59 return regmap_read(data->map, IDIO_16_ENABLE_IRQ, &val); 60 } 61 62 /* if all are currently masked, disable interrupts */ 63 if (mask_buf == mask_buf_def) 64 return regmap_write(data->map, IDIO_16_DISABLE_IRQ, 0x00); 65 66 return 0; 67 } 68 69 static int idio_16_reg_mask_xlate(struct gpio_regmap *const gpio, const unsigned int base, 70 const unsigned int offset, unsigned int *const reg, 71 unsigned int *const mask) 72 { 73 unsigned int stride; 74 75 /* Input lines start at GPIO 16 */ 76 if (offset < 16) { 77 stride = offset / IDIO_16_NGPIO_PER_REG; 78 *reg = IDIO_16_OUT_BASE + stride * IDIO_16_REG_STRIDE; 79 } else { 80 stride = (offset - 16) / IDIO_16_NGPIO_PER_REG; 81 *reg = IDIO_16_IN_BASE + stride * IDIO_16_REG_STRIDE; 82 } 83 84 *mask = BIT(offset % IDIO_16_NGPIO_PER_REG); 85 86 return 0; 87 } 88 89 static const char *idio_16_names[IDIO_16_NGPIO] = { 90 "OUT0", "OUT1", "OUT2", "OUT3", "OUT4", "OUT5", "OUT6", "OUT7", 91 "OUT8", "OUT9", "OUT10", "OUT11", "OUT12", "OUT13", "OUT14", "OUT15", 92 "IIN0", "IIN1", "IIN2", "IIN3", "IIN4", "IIN5", "IIN6", "IIN7", 93 "IIN8", "IIN9", "IIN10", "IIN11", "IIN12", "IIN13", "IIN14", "IIN15", 94 }; 95 96 /** 97 * devm_idio_16_regmap_register - Register an IDIO-16 GPIO device 98 * @dev: device that is registering this IDIO-16 GPIO device 99 * @config: configuration for idio_16_regmap_config 100 * 101 * Registers an IDIO-16 GPIO device. Returns 0 on success and negative error number on failure. 102 */ 103 int devm_idio_16_regmap_register(struct device *const dev, 104 const struct idio_16_regmap_config *const config) 105 { 106 struct gpio_regmap_config gpio_config = {}; 107 int err; 108 struct idio_16_data *data; 109 struct regmap_irq_chip *chip; 110 struct regmap_irq_chip_data *chip_data; 111 DECLARE_BITMAP(fixed_direction_output, IDIO_16_NGPIO); 112 113 if (!config->parent) 114 return -EINVAL; 115 116 if (!config->map) 117 return -EINVAL; 118 119 if (!config->regmap_irqs) 120 return -EINVAL; 121 122 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); 123 if (!data) 124 return -ENOMEM; 125 data->map = config->map; 126 127 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL); 128 if (!chip) 129 return -ENOMEM; 130 131 chip->name = dev_name(dev); 132 chip->status_base = IDIO_16_INTERRUPT_STATUS; 133 chip->mask_base = IDIO_16_ENABLE_IRQ; 134 chip->ack_base = IDIO_16_CLEAR_INTERRUPT; 135 chip->no_status = config->no_status; 136 chip->num_regs = 1; 137 chip->irqs = config->regmap_irqs; 138 chip->num_irqs = config->num_regmap_irqs; 139 chip->handle_mask_sync = idio_16_handle_mask_sync; 140 chip->irq_drv_data = data; 141 142 /* Disable IRQ to prevent spurious interrupts before we're ready */ 143 err = regmap_write(data->map, IDIO_16_DISABLE_IRQ, 0x00); 144 if (err) 145 return err; 146 147 err = devm_regmap_add_irq_chip(dev, data->map, config->irq, 0, 0, chip, &chip_data); 148 if (err) 149 return dev_err_probe(dev, err, "IRQ registration failed\n"); 150 151 if (config->filters) { 152 /* Deactivate input filters */ 153 err = regmap_write(data->map, IDIO_16_DEACTIVATE_INPUT_FILTERS, 0x00); 154 if (err) 155 return err; 156 } 157 158 gpio_config.parent = config->parent; 159 gpio_config.regmap = data->map; 160 gpio_config.ngpio = IDIO_16_NGPIO; 161 gpio_config.names = idio_16_names; 162 gpio_config.reg_dat_base = GPIO_REGMAP_ADDR(IDIO_16_DAT_BASE); 163 gpio_config.reg_set_base = GPIO_REGMAP_ADDR(IDIO_16_DAT_BASE); 164 gpio_config.ngpio_per_reg = IDIO_16_NGPIO_PER_REG; 165 gpio_config.reg_stride = IDIO_16_REG_STRIDE; 166 gpio_config.irq_domain = regmap_irq_get_domain(chip_data); 167 gpio_config.reg_mask_xlate = idio_16_reg_mask_xlate; 168 169 bitmap_from_u64(fixed_direction_output, GENMASK_U64(15, 0)); 170 gpio_config.fixed_direction_output = fixed_direction_output; 171 172 return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(dev, &gpio_config)); 173 } 174 EXPORT_SYMBOL_GPL(devm_idio_16_regmap_register); 175 176 MODULE_AUTHOR("William Breathitt Gray"); 177 MODULE_DESCRIPTION("ACCES IDIO-16 GPIO Library"); 178 MODULE_LICENSE("GPL"); 179