1 // SPDX-License-Identifier: GPL-2.0-only 2 /* Abilis Systems MODULE DESCRIPTION 3 * 4 * Copyright (C) Abilis Systems 2013 5 * 6 * Authors: Sascha Leuenberger <sascha.leuenberger@abilis.com> 7 * Christian Ruppert <christian.ruppert@abilis.com> 8 */ 9 10 #include <linux/bitops.h> 11 #include <linux/gpio/driver.h> 12 #include <linux/gpio/generic.h> 13 #include <linux/interrupt.h> 14 #include <linux/io.h> 15 #include <linux/irq.h> 16 #include <linux/irqdomain.h> 17 #include <linux/kernel.h> 18 #include <linux/module.h> 19 #include <linux/of.h> 20 #include <linux/of_platform.h> 21 #include <linux/pinctrl/consumer.h> 22 #include <linux/platform_device.h> 23 #include <linux/slab.h> 24 25 #define TB10X_GPIO_DIR_IN (0x00000000) 26 #define TB10X_GPIO_DIR_OUT (0x00000001) 27 #define OFFSET_TO_REG_DDR (0x00) 28 #define OFFSET_TO_REG_DATA (0x04) 29 #define OFFSET_TO_REG_INT_EN (0x08) 30 #define OFFSET_TO_REG_CHANGE (0x0C) 31 #define OFFSET_TO_REG_WRMASK (0x10) 32 #define OFFSET_TO_REG_INT_TYPE (0x14) 33 34 35 /** 36 * @base: register base address 37 * @domain: IRQ domain of GPIO generated interrupts managed by this controller 38 * @irq: Interrupt line of parent interrupt controller 39 * @chip: Generic GPIO chip structure associated with this GPIO controller 40 */ 41 struct tb10x_gpio { 42 void __iomem *base; 43 struct irq_domain *domain; 44 int irq; 45 struct gpio_generic_chip chip; 46 }; 47 48 static inline u32 tb10x_reg_read(struct tb10x_gpio *gpio, unsigned int offs) 49 { 50 return ioread32(gpio->base + offs); 51 } 52 53 static int tb10x_gpio_to_irq(struct gpio_chip *chip, unsigned offset) 54 { 55 struct tb10x_gpio *tb10x_gpio = gpiochip_get_data(chip); 56 57 return irq_create_mapping(tb10x_gpio->domain, offset); 58 } 59 60 static int tb10x_gpio_irq_set_type(struct irq_data *data, unsigned int type) 61 { 62 if ((type & IRQF_TRIGGER_MASK) != IRQ_TYPE_EDGE_BOTH) { 63 pr_err("Only (both) edge triggered interrupts supported.\n"); 64 return -EINVAL; 65 } 66 67 irqd_set_trigger_type(data, type); 68 69 return IRQ_SET_MASK_OK; 70 } 71 72 static irqreturn_t tb10x_gpio_irq_cascade(int irq, void *data) 73 { 74 struct tb10x_gpio *tb10x_gpio = data; 75 u32 r = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_CHANGE); 76 u32 m = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_INT_EN); 77 const unsigned long bits = r & m; 78 int i; 79 80 for_each_set_bit(i, &bits, 32) 81 generic_handle_domain_irq(tb10x_gpio->domain, i); 82 83 return IRQ_HANDLED; 84 } 85 86 static int tb10x_gpio_probe(struct platform_device *pdev) 87 { 88 struct gpio_generic_chip_config config; 89 struct tb10x_gpio *tb10x_gpio; 90 struct device *dev = &pdev->dev; 91 struct device_node *np = dev->of_node; 92 int ret = -EBUSY; 93 u32 ngpio; 94 95 if (!np) 96 return -EINVAL; 97 98 if (of_property_read_u32(np, "abilis,ngpio", &ngpio)) 99 return -EINVAL; 100 101 tb10x_gpio = devm_kzalloc(dev, sizeof(*tb10x_gpio), GFP_KERNEL); 102 if (tb10x_gpio == NULL) 103 return -ENOMEM; 104 105 tb10x_gpio->base = devm_platform_ioremap_resource(pdev, 0); 106 if (IS_ERR(tb10x_gpio->base)) 107 return PTR_ERR(tb10x_gpio->base); 108 109 tb10x_gpio->chip.gc.label = 110 devm_kasprintf(dev, GFP_KERNEL, "%pOF", pdev->dev.of_node); 111 if (!tb10x_gpio->chip.gc.label) 112 return -ENOMEM; 113 114 /* 115 * Initialize generic GPIO with one single register for reading and setting 116 * the lines, no special set or clear registers and a data direction register 117 * wher 1 means "output". 118 */ 119 config = (struct gpio_generic_chip_config) { 120 .dev = dev, 121 .sz = 4, 122 .dat = tb10x_gpio->base + OFFSET_TO_REG_DATA, 123 .dirout = tb10x_gpio->base + OFFSET_TO_REG_DDR, 124 }; 125 126 ret = gpio_generic_chip_init(&tb10x_gpio->chip, &config); 127 if (ret) { 128 dev_err(dev, "unable to init generic GPIO\n"); 129 return ret; 130 } 131 tb10x_gpio->chip.gc.base = -1; 132 tb10x_gpio->chip.gc.parent = dev; 133 tb10x_gpio->chip.gc.owner = THIS_MODULE; 134 /* 135 * ngpio is set by gpio_generic_chip_init() but we override it, this 136 * .request() callback also overrides the one set up by generic GPIO. 137 */ 138 tb10x_gpio->chip.gc.ngpio = ngpio; 139 tb10x_gpio->chip.gc.request = gpiochip_generic_request; 140 tb10x_gpio->chip.gc.free = gpiochip_generic_free; 141 142 ret = devm_gpiochip_add_data(dev, &tb10x_gpio->chip.gc, tb10x_gpio); 143 if (ret < 0) { 144 dev_err(dev, "Could not add gpiochip.\n"); 145 return ret; 146 } 147 148 platform_set_drvdata(pdev, tb10x_gpio); 149 150 if (of_property_read_bool(np, "interrupt-controller")) { 151 struct irq_chip_generic *gc; 152 153 ret = platform_get_irq(pdev, 0); 154 if (ret < 0) 155 return ret; 156 157 tb10x_gpio->chip.gc.to_irq = tb10x_gpio_to_irq; 158 tb10x_gpio->irq = ret; 159 160 ret = devm_request_irq(dev, ret, tb10x_gpio_irq_cascade, 161 IRQF_TRIGGER_NONE | IRQF_SHARED, 162 dev_name(dev), tb10x_gpio); 163 if (ret != 0) 164 return ret; 165 166 tb10x_gpio->domain = irq_domain_create_linear(dev_fwnode(dev), 167 tb10x_gpio->chip.gc.ngpio, 168 &irq_generic_chip_ops, NULL); 169 if (!tb10x_gpio->domain) { 170 return -ENOMEM; 171 } 172 173 ret = irq_alloc_domain_generic_chips(tb10x_gpio->domain, 174 tb10x_gpio->chip.gc.ngpio, 1, tb10x_gpio->chip.gc.label, 175 handle_edge_irq, IRQ_NOREQUEST, IRQ_NOPROBE, 176 IRQ_GC_INIT_MASK_CACHE); 177 if (ret) 178 goto err_remove_domain; 179 180 gc = tb10x_gpio->domain->gc->gc[0]; 181 gc->reg_base = tb10x_gpio->base; 182 gc->chip_types[0].type = IRQ_TYPE_EDGE_BOTH; 183 gc->chip_types[0].chip.irq_ack = irq_gc_ack_set_bit; 184 gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit; 185 gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit; 186 gc->chip_types[0].chip.irq_set_type = tb10x_gpio_irq_set_type; 187 gc->chip_types[0].regs.ack = OFFSET_TO_REG_CHANGE; 188 gc->chip_types[0].regs.mask = OFFSET_TO_REG_INT_EN; 189 } 190 191 return 0; 192 193 err_remove_domain: 194 irq_domain_remove(tb10x_gpio->domain); 195 return ret; 196 } 197 198 static void tb10x_gpio_remove(struct platform_device *pdev) 199 { 200 struct tb10x_gpio *tb10x_gpio = platform_get_drvdata(pdev); 201 202 if (tb10x_gpio->chip.gc.to_irq) { 203 irq_remove_generic_chip(tb10x_gpio->domain->gc->gc[0], 204 BIT(tb10x_gpio->chip.gc.ngpio) - 1, 0, 0); 205 kfree(tb10x_gpio->domain->gc); 206 irq_domain_remove(tb10x_gpio->domain); 207 } 208 } 209 210 static const struct of_device_id tb10x_gpio_dt_ids[] = { 211 { .compatible = "abilis,tb10x-gpio" }, 212 { } 213 }; 214 MODULE_DEVICE_TABLE(of, tb10x_gpio_dt_ids); 215 216 static struct platform_driver tb10x_gpio_driver = { 217 .probe = tb10x_gpio_probe, 218 .remove = tb10x_gpio_remove, 219 .driver = { 220 .name = "tb10x-gpio", 221 .of_match_table = tb10x_gpio_dt_ids, 222 } 223 }; 224 225 module_platform_driver(tb10x_gpio_driver); 226 MODULE_LICENSE("GPL"); 227 MODULE_DESCRIPTION("tb10x gpio."); 228