1 /* Abilis Systems MODULE DESCRIPTION 2 * 3 * Copyright (C) Abilis Systems 2013 4 * 5 * Authors: Sascha Leuenberger <sascha.leuenberger@abilis.com> 6 * Christian Ruppert <christian.ruppert@abilis.com> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 20 */ 21 22 #include <linux/kernel.h> 23 #include <linux/module.h> 24 #include <linux/platform_device.h> 25 #include <linux/gpio.h> 26 #include <linux/slab.h> 27 #include <linux/irq.h> 28 #include <linux/irqdomain.h> 29 #include <linux/interrupt.h> 30 #include <linux/io.h> 31 #include <linux/of.h> 32 #include <linux/of_platform.h> 33 #include <linux/of_gpio.h> 34 #include <linux/spinlock.h> 35 #include <linux/bitops.h> 36 #include <linux/pinctrl/consumer.h> 37 38 #define TB10X_GPIO_DIR_IN (0x00000000) 39 #define TB10X_GPIO_DIR_OUT (0x00000001) 40 #define OFFSET_TO_REG_DDR (0x00) 41 #define OFFSET_TO_REG_DATA (0x04) 42 #define OFFSET_TO_REG_INT_EN (0x08) 43 #define OFFSET_TO_REG_CHANGE (0x0C) 44 #define OFFSET_TO_REG_WRMASK (0x10) 45 #define OFFSET_TO_REG_INT_TYPE (0x14) 46 47 48 /** 49 * @spinlock: used for atomic read/modify/write of registers 50 * @base: register base address 51 * @domain: IRQ domain of GPIO generated interrupts managed by this controller 52 * @irq: Interrupt line of parent interrupt controller 53 * @gc: gpio_chip structure associated to this GPIO controller 54 */ 55 struct tb10x_gpio { 56 spinlock_t spinlock; 57 void __iomem *base; 58 struct irq_domain *domain; 59 int irq; 60 struct gpio_chip gc; 61 }; 62 63 static inline u32 tb10x_reg_read(struct tb10x_gpio *gpio, unsigned int offs) 64 { 65 return ioread32(gpio->base + offs); 66 } 67 68 static inline void tb10x_reg_write(struct tb10x_gpio *gpio, unsigned int offs, 69 u32 val) 70 { 71 iowrite32(val, gpio->base + offs); 72 } 73 74 static inline void tb10x_set_bits(struct tb10x_gpio *gpio, unsigned int offs, 75 u32 mask, u32 val) 76 { 77 u32 r; 78 unsigned long flags; 79 80 spin_lock_irqsave(&gpio->spinlock, flags); 81 82 r = tb10x_reg_read(gpio, offs); 83 r = (r & ~mask) | (val & mask); 84 85 tb10x_reg_write(gpio, offs, r); 86 87 spin_unlock_irqrestore(&gpio->spinlock, flags); 88 } 89 90 static inline struct tb10x_gpio *to_tb10x_gpio(struct gpio_chip *chip) 91 { 92 return container_of(chip, struct tb10x_gpio, gc); 93 } 94 95 static int tb10x_gpio_direction_in(struct gpio_chip *chip, unsigned offset) 96 { 97 struct tb10x_gpio *tb10x_gpio = to_tb10x_gpio(chip); 98 int mask = BIT(offset); 99 int val = TB10X_GPIO_DIR_IN << offset; 100 101 tb10x_set_bits(tb10x_gpio, OFFSET_TO_REG_DDR, mask, val); 102 103 return 0; 104 } 105 106 static int tb10x_gpio_get(struct gpio_chip *chip, unsigned offset) 107 { 108 struct tb10x_gpio *tb10x_gpio = to_tb10x_gpio(chip); 109 int val; 110 111 val = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_DATA); 112 113 if (val & BIT(offset)) 114 return 1; 115 else 116 return 0; 117 } 118 119 static void tb10x_gpio_set(struct gpio_chip *chip, unsigned offset, int value) 120 { 121 struct tb10x_gpio *tb10x_gpio = to_tb10x_gpio(chip); 122 int mask = BIT(offset); 123 int val = value << offset; 124 125 tb10x_set_bits(tb10x_gpio, OFFSET_TO_REG_DATA, mask, val); 126 } 127 128 static int tb10x_gpio_direction_out(struct gpio_chip *chip, 129 unsigned offset, int value) 130 { 131 struct tb10x_gpio *tb10x_gpio = to_tb10x_gpio(chip); 132 int mask = BIT(offset); 133 int val = TB10X_GPIO_DIR_OUT << offset; 134 135 tb10x_gpio_set(chip, offset, value); 136 tb10x_set_bits(tb10x_gpio, OFFSET_TO_REG_DDR, mask, val); 137 138 return 0; 139 } 140 141 static int tb10x_gpio_request(struct gpio_chip *chip, unsigned offset) 142 { 143 return pinctrl_request_gpio(chip->base + offset); 144 } 145 146 static void tb10x_gpio_free(struct gpio_chip *chip, unsigned offset) 147 { 148 pinctrl_free_gpio(chip->base + offset); 149 } 150 151 static int tb10x_gpio_to_irq(struct gpio_chip *chip, unsigned offset) 152 { 153 struct tb10x_gpio *tb10x_gpio = to_tb10x_gpio(chip); 154 155 return irq_create_mapping(tb10x_gpio->domain, offset); 156 } 157 158 static int tb10x_gpio_irq_set_type(struct irq_data *data, unsigned int type) 159 { 160 if ((type & IRQF_TRIGGER_MASK) != IRQ_TYPE_EDGE_BOTH) { 161 pr_err("Only (both) edge triggered interrupts supported.\n"); 162 return -EINVAL; 163 } 164 165 irqd_set_trigger_type(data, type); 166 167 return IRQ_SET_MASK_OK; 168 } 169 170 static irqreturn_t tb10x_gpio_irq_cascade(int irq, void *data) 171 { 172 struct tb10x_gpio *tb10x_gpio = data; 173 u32 r = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_CHANGE); 174 u32 m = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_INT_EN); 175 const unsigned long bits = r & m; 176 int i; 177 178 for_each_set_bit(i, &bits, 32) 179 generic_handle_irq(irq_find_mapping(tb10x_gpio->domain, i)); 180 181 return IRQ_HANDLED; 182 } 183 184 static int tb10x_gpio_probe(struct platform_device *pdev) 185 { 186 struct tb10x_gpio *tb10x_gpio; 187 struct resource *mem; 188 struct device_node *dn = pdev->dev.of_node; 189 int ret = -EBUSY; 190 u32 ngpio; 191 192 if (!dn) 193 return -EINVAL; 194 195 if (of_property_read_u32(dn, "abilis,ngpio", &ngpio)) 196 return -EINVAL; 197 198 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 199 if (!mem) { 200 dev_err(&pdev->dev, "No memory resource defined.\n"); 201 return -EINVAL; 202 } 203 204 tb10x_gpio = devm_kzalloc(&pdev->dev, sizeof(*tb10x_gpio), GFP_KERNEL); 205 if (tb10x_gpio == NULL) 206 return -ENOMEM; 207 208 spin_lock_init(&tb10x_gpio->spinlock); 209 210 tb10x_gpio->base = devm_ioremap_resource(&pdev->dev, mem); 211 if (IS_ERR(tb10x_gpio->base)) 212 return PTR_ERR(tb10x_gpio->base); 213 214 tb10x_gpio->gc.label = of_node_full_name(dn); 215 tb10x_gpio->gc.dev = &pdev->dev; 216 tb10x_gpio->gc.owner = THIS_MODULE; 217 tb10x_gpio->gc.direction_input = tb10x_gpio_direction_in; 218 tb10x_gpio->gc.get = tb10x_gpio_get; 219 tb10x_gpio->gc.direction_output = tb10x_gpio_direction_out; 220 tb10x_gpio->gc.set = tb10x_gpio_set; 221 tb10x_gpio->gc.request = tb10x_gpio_request; 222 tb10x_gpio->gc.free = tb10x_gpio_free; 223 tb10x_gpio->gc.base = -1; 224 tb10x_gpio->gc.ngpio = ngpio; 225 tb10x_gpio->gc.can_sleep = false; 226 227 228 ret = gpiochip_add(&tb10x_gpio->gc); 229 if (ret < 0) { 230 dev_err(&pdev->dev, "Could not add gpiochip.\n"); 231 goto fail_gpiochip_registration; 232 } 233 234 platform_set_drvdata(pdev, tb10x_gpio); 235 236 if (of_find_property(dn, "interrupt-controller", NULL)) { 237 struct irq_chip_generic *gc; 238 239 ret = platform_get_irq(pdev, 0); 240 if (ret < 0) { 241 dev_err(&pdev->dev, "No interrupt specified.\n"); 242 goto fail_get_irq; 243 } 244 245 tb10x_gpio->gc.to_irq = tb10x_gpio_to_irq; 246 tb10x_gpio->irq = ret; 247 248 ret = devm_request_irq(&pdev->dev, ret, tb10x_gpio_irq_cascade, 249 IRQF_TRIGGER_NONE | IRQF_SHARED, 250 dev_name(&pdev->dev), tb10x_gpio); 251 if (ret != 0) 252 goto fail_request_irq; 253 254 tb10x_gpio->domain = irq_domain_add_linear(dn, 255 tb10x_gpio->gc.ngpio, 256 &irq_generic_chip_ops, NULL); 257 if (!tb10x_gpio->domain) { 258 ret = -ENOMEM; 259 goto fail_irq_domain; 260 } 261 262 ret = irq_alloc_domain_generic_chips(tb10x_gpio->domain, 263 tb10x_gpio->gc.ngpio, 1, tb10x_gpio->gc.label, 264 handle_edge_irq, IRQ_NOREQUEST, IRQ_NOPROBE, 265 IRQ_GC_INIT_MASK_CACHE); 266 if (ret) 267 goto fail_irq_domain; 268 269 gc = tb10x_gpio->domain->gc->gc[0]; 270 gc->reg_base = tb10x_gpio->base; 271 gc->chip_types[0].type = IRQ_TYPE_EDGE_BOTH; 272 gc->chip_types[0].chip.irq_ack = irq_gc_ack_set_bit; 273 gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit; 274 gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit; 275 gc->chip_types[0].chip.irq_set_type = tb10x_gpio_irq_set_type; 276 gc->chip_types[0].regs.ack = OFFSET_TO_REG_CHANGE; 277 gc->chip_types[0].regs.mask = OFFSET_TO_REG_INT_EN; 278 } 279 280 return 0; 281 282 fail_irq_domain: 283 fail_request_irq: 284 fail_get_irq: 285 gpiochip_remove(&tb10x_gpio->gc); 286 fail_gpiochip_registration: 287 fail_ioremap: 288 return ret; 289 } 290 291 static int __exit tb10x_gpio_remove(struct platform_device *pdev) 292 { 293 struct tb10x_gpio *tb10x_gpio = platform_get_drvdata(pdev); 294 295 if (tb10x_gpio->gc.to_irq) { 296 irq_remove_generic_chip(tb10x_gpio->domain->gc->gc[0], 297 BIT(tb10x_gpio->gc.ngpio) - 1, 0, 0); 298 kfree(tb10x_gpio->domain->gc); 299 irq_domain_remove(tb10x_gpio->domain); 300 free_irq(tb10x_gpio->irq, tb10x_gpio); 301 } 302 gpiochip_remove(&tb10x_gpio->gc); 303 304 return 0; 305 } 306 307 static const struct of_device_id tb10x_gpio_dt_ids[] = { 308 { .compatible = "abilis,tb10x-gpio" }, 309 { } 310 }; 311 MODULE_DEVICE_TABLE(of, tb10x_gpio_dt_ids); 312 313 static struct platform_driver tb10x_gpio_driver = { 314 .probe = tb10x_gpio_probe, 315 .remove = tb10x_gpio_remove, 316 .driver = { 317 .name = "tb10x-gpio", 318 .of_match_table = tb10x_gpio_dt_ids, 319 .owner = THIS_MODULE, 320 } 321 }; 322 323 module_platform_driver(tb10x_gpio_driver); 324 MODULE_LICENSE("GPL"); 325 MODULE_DESCRIPTION("tb10x gpio."); 326 MODULE_VERSION("0.0.1"); 327