1 /* 2 * Timberdale FPGA GPIO driver 3 * Copyright (c) 2009 Intel Corporation 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License version 2 as 7 * published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write to the Free Software 16 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 17 */ 18 19 /* Supports: 20 * Timberdale FPGA GPIO 21 */ 22 23 #include <linux/module.h> 24 #include <linux/gpio.h> 25 #include <linux/platform_device.h> 26 #include <linux/irq.h> 27 #include <linux/io.h> 28 #include <linux/timb_gpio.h> 29 #include <linux/interrupt.h> 30 #include <linux/slab.h> 31 32 #define DRIVER_NAME "timb-gpio" 33 34 #define TGPIOVAL 0x00 35 #define TGPIODIR 0x04 36 #define TGPIO_IER 0x08 37 #define TGPIO_ISR 0x0c 38 #define TGPIO_IPR 0x10 39 #define TGPIO_ICR 0x14 40 #define TGPIO_FLR 0x18 41 #define TGPIO_LVR 0x1c 42 #define TGPIO_VER 0x20 43 #define TGPIO_BFLR 0x24 44 45 struct timbgpio { 46 void __iomem *membase; 47 spinlock_t lock; /* mutual exclusion */ 48 struct gpio_chip gpio; 49 int irq_base; 50 unsigned long last_ier; 51 }; 52 53 static int timbgpio_update_bit(struct gpio_chip *gpio, unsigned index, 54 unsigned offset, bool enabled) 55 { 56 struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio); 57 u32 reg; 58 59 spin_lock(&tgpio->lock); 60 reg = ioread32(tgpio->membase + offset); 61 62 if (enabled) 63 reg |= (1 << index); 64 else 65 reg &= ~(1 << index); 66 67 iowrite32(reg, tgpio->membase + offset); 68 spin_unlock(&tgpio->lock); 69 70 return 0; 71 } 72 73 static int timbgpio_gpio_direction_input(struct gpio_chip *gpio, unsigned nr) 74 { 75 return timbgpio_update_bit(gpio, nr, TGPIODIR, true); 76 } 77 78 static int timbgpio_gpio_get(struct gpio_chip *gpio, unsigned nr) 79 { 80 struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio); 81 u32 value; 82 83 value = ioread32(tgpio->membase + TGPIOVAL); 84 return (value & (1 << nr)) ? 1 : 0; 85 } 86 87 static int timbgpio_gpio_direction_output(struct gpio_chip *gpio, 88 unsigned nr, int val) 89 { 90 return timbgpio_update_bit(gpio, nr, TGPIODIR, false); 91 } 92 93 static void timbgpio_gpio_set(struct gpio_chip *gpio, 94 unsigned nr, int val) 95 { 96 timbgpio_update_bit(gpio, nr, TGPIOVAL, val != 0); 97 } 98 99 static int timbgpio_to_irq(struct gpio_chip *gpio, unsigned offset) 100 { 101 struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio); 102 103 if (tgpio->irq_base <= 0) 104 return -EINVAL; 105 106 return tgpio->irq_base + offset; 107 } 108 109 /* 110 * GPIO IRQ 111 */ 112 static void timbgpio_irq_disable(struct irq_data *d) 113 { 114 struct timbgpio *tgpio = irq_data_get_irq_chip_data(d); 115 int offset = d->irq - tgpio->irq_base; 116 unsigned long flags; 117 118 spin_lock_irqsave(&tgpio->lock, flags); 119 tgpio->last_ier &= ~(1UL << offset); 120 iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER); 121 spin_unlock_irqrestore(&tgpio->lock, flags); 122 } 123 124 static void timbgpio_irq_enable(struct irq_data *d) 125 { 126 struct timbgpio *tgpio = irq_data_get_irq_chip_data(d); 127 int offset = d->irq - tgpio->irq_base; 128 unsigned long flags; 129 130 spin_lock_irqsave(&tgpio->lock, flags); 131 tgpio->last_ier |= 1UL << offset; 132 iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER); 133 spin_unlock_irqrestore(&tgpio->lock, flags); 134 } 135 136 static int timbgpio_irq_type(struct irq_data *d, unsigned trigger) 137 { 138 struct timbgpio *tgpio = irq_data_get_irq_chip_data(d); 139 int offset = d->irq - tgpio->irq_base; 140 unsigned long flags; 141 u32 lvr, flr, bflr = 0; 142 u32 ver; 143 int ret = 0; 144 145 if (offset < 0 || offset > tgpio->gpio.ngpio) 146 return -EINVAL; 147 148 ver = ioread32(tgpio->membase + TGPIO_VER); 149 150 spin_lock_irqsave(&tgpio->lock, flags); 151 152 lvr = ioread32(tgpio->membase + TGPIO_LVR); 153 flr = ioread32(tgpio->membase + TGPIO_FLR); 154 if (ver > 2) 155 bflr = ioread32(tgpio->membase + TGPIO_BFLR); 156 157 if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) { 158 bflr &= ~(1 << offset); 159 flr &= ~(1 << offset); 160 if (trigger & IRQ_TYPE_LEVEL_HIGH) 161 lvr |= 1 << offset; 162 else 163 lvr &= ~(1 << offset); 164 } 165 166 if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) { 167 if (ver < 3) { 168 ret = -EINVAL; 169 goto out; 170 } else { 171 flr |= 1 << offset; 172 bflr |= 1 << offset; 173 } 174 } else { 175 bflr &= ~(1 << offset); 176 flr |= 1 << offset; 177 if (trigger & IRQ_TYPE_EDGE_FALLING) 178 lvr &= ~(1 << offset); 179 else 180 lvr |= 1 << offset; 181 } 182 183 iowrite32(lvr, tgpio->membase + TGPIO_LVR); 184 iowrite32(flr, tgpio->membase + TGPIO_FLR); 185 if (ver > 2) 186 iowrite32(bflr, tgpio->membase + TGPIO_BFLR); 187 188 iowrite32(1 << offset, tgpio->membase + TGPIO_ICR); 189 190 out: 191 spin_unlock_irqrestore(&tgpio->lock, flags); 192 return ret; 193 } 194 195 static void timbgpio_irq(unsigned int irq, struct irq_desc *desc) 196 { 197 struct timbgpio *tgpio = irq_get_handler_data(irq); 198 unsigned long ipr; 199 int offset; 200 201 desc->irq_data.chip->irq_ack(irq_get_irq_data(irq)); 202 ipr = ioread32(tgpio->membase + TGPIO_IPR); 203 iowrite32(ipr, tgpio->membase + TGPIO_ICR); 204 205 /* 206 * Some versions of the hardware trash the IER register if more than 207 * one interrupt is received simultaneously. 208 */ 209 iowrite32(0, tgpio->membase + TGPIO_IER); 210 211 for_each_set_bit(offset, &ipr, tgpio->gpio.ngpio) 212 generic_handle_irq(timbgpio_to_irq(&tgpio->gpio, offset)); 213 214 iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER); 215 } 216 217 static struct irq_chip timbgpio_irqchip = { 218 .name = "GPIO", 219 .irq_enable = timbgpio_irq_enable, 220 .irq_disable = timbgpio_irq_disable, 221 .irq_set_type = timbgpio_irq_type, 222 }; 223 224 static int timbgpio_probe(struct platform_device *pdev) 225 { 226 int err, i; 227 struct device *dev = &pdev->dev; 228 struct gpio_chip *gc; 229 struct timbgpio *tgpio; 230 struct resource *iomem; 231 struct timbgpio_platform_data *pdata = dev_get_platdata(&pdev->dev); 232 int irq = platform_get_irq(pdev, 0); 233 234 if (!pdata || pdata->nr_pins > 32) { 235 dev_err(dev, "Invalid platform data\n"); 236 return -EINVAL; 237 } 238 239 iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 240 if (!iomem) { 241 dev_err(dev, "Unable to get resource\n"); 242 return -EINVAL; 243 } 244 245 tgpio = devm_kzalloc(dev, sizeof(struct timbgpio), GFP_KERNEL); 246 if (!tgpio) { 247 dev_err(dev, "Memory alloc failed\n"); 248 return -EINVAL; 249 } 250 tgpio->irq_base = pdata->irq_base; 251 252 spin_lock_init(&tgpio->lock); 253 254 if (!devm_request_mem_region(dev, iomem->start, resource_size(iomem), 255 DRIVER_NAME)) { 256 dev_err(dev, "Region already claimed\n"); 257 return -EBUSY; 258 } 259 260 tgpio->membase = devm_ioremap(dev, iomem->start, resource_size(iomem)); 261 if (!tgpio->membase) { 262 dev_err(dev, "Cannot ioremap\n"); 263 return -ENOMEM; 264 } 265 266 gc = &tgpio->gpio; 267 268 gc->label = dev_name(&pdev->dev); 269 gc->owner = THIS_MODULE; 270 gc->dev = &pdev->dev; 271 gc->direction_input = timbgpio_gpio_direction_input; 272 gc->get = timbgpio_gpio_get; 273 gc->direction_output = timbgpio_gpio_direction_output; 274 gc->set = timbgpio_gpio_set; 275 gc->to_irq = (irq >= 0 && tgpio->irq_base > 0) ? timbgpio_to_irq : NULL; 276 gc->dbg_show = NULL; 277 gc->base = pdata->gpio_base; 278 gc->ngpio = pdata->nr_pins; 279 gc->can_sleep = false; 280 281 err = gpiochip_add(gc); 282 if (err) 283 return err; 284 285 platform_set_drvdata(pdev, tgpio); 286 287 /* make sure to disable interrupts */ 288 iowrite32(0x0, tgpio->membase + TGPIO_IER); 289 290 if (irq < 0 || tgpio->irq_base <= 0) 291 return 0; 292 293 for (i = 0; i < pdata->nr_pins; i++) { 294 irq_set_chip_and_handler(tgpio->irq_base + i, 295 &timbgpio_irqchip, handle_simple_irq); 296 irq_set_chip_data(tgpio->irq_base + i, tgpio); 297 #ifdef CONFIG_ARM 298 set_irq_flags(tgpio->irq_base + i, IRQF_VALID | IRQF_PROBE); 299 #endif 300 } 301 302 irq_set_handler_data(irq, tgpio); 303 irq_set_chained_handler(irq, timbgpio_irq); 304 305 return 0; 306 } 307 308 static int timbgpio_remove(struct platform_device *pdev) 309 { 310 struct timbgpio_platform_data *pdata = dev_get_platdata(&pdev->dev); 311 struct timbgpio *tgpio = platform_get_drvdata(pdev); 312 int irq = platform_get_irq(pdev, 0); 313 314 if (irq >= 0 && tgpio->irq_base > 0) { 315 int i; 316 for (i = 0; i < pdata->nr_pins; i++) { 317 irq_set_chip(tgpio->irq_base + i, NULL); 318 irq_set_chip_data(tgpio->irq_base + i, NULL); 319 } 320 321 irq_set_handler(irq, NULL); 322 irq_set_handler_data(irq, NULL); 323 } 324 325 gpiochip_remove(&tgpio->gpio); 326 327 return 0; 328 } 329 330 static struct platform_driver timbgpio_platform_driver = { 331 .driver = { 332 .name = DRIVER_NAME, 333 }, 334 .probe = timbgpio_probe, 335 .remove = timbgpio_remove, 336 }; 337 338 /*--------------------------------------------------------------------------*/ 339 340 module_platform_driver(timbgpio_platform_driver); 341 342 MODULE_DESCRIPTION("Timberdale GPIO driver"); 343 MODULE_LICENSE("GPL v2"); 344 MODULE_AUTHOR("Mocean Laboratories"); 345 MODULE_ALIAS("platform:"DRIVER_NAME); 346 347