Damian Hobson-Garcia | 0a0c3b5 | 2012-09-25 15:09:11 +0900 | [diff] [blame] | 1 | /* |
| 2 | * drivers/uio/uio_dmem_genirq.c |
| 3 | * |
| 4 | * Userspace I/O platform driver with generic IRQ handling code. |
| 5 | * |
| 6 | * Copyright (C) 2012 Damian Hobson-Garcia |
| 7 | * |
| 8 | * Based on uio_pdrv_genirq.c by Magnus Damm |
| 9 | * |
| 10 | * This program is free software; you can redistribute it and/or modify it |
| 11 | * under the terms of the GNU General Public License version 2 as published by |
| 12 | * the Free Software Foundation. |
| 13 | */ |
| 14 | |
| 15 | #include <linux/platform_device.h> |
| 16 | #include <linux/uio_driver.h> |
| 17 | #include <linux/spinlock.h> |
| 18 | #include <linux/bitops.h> |
| 19 | #include <linux/module.h> |
| 20 | #include <linux/interrupt.h> |
| 21 | #include <linux/platform_data/uio_dmem_genirq.h> |
| 22 | #include <linux/stringify.h> |
| 23 | #include <linux/pm_runtime.h> |
| 24 | #include <linux/dma-mapping.h> |
| 25 | #include <linux/slab.h> |
| 26 | |
| 27 | #include <linux/of.h> |
| 28 | #include <linux/of_platform.h> |
| 29 | #include <linux/of_address.h> |
| 30 | |
| 31 | #define DRIVER_NAME "uio_dmem_genirq" |
Damian Hobson-Garcia | 87c4d1a | 2012-11-16 14:46:10 +0900 | [diff] [blame] | 32 | #define DMEM_MAP_ERROR (~0) |
Damian Hobson-Garcia | 0a0c3b5 | 2012-09-25 15:09:11 +0900 | [diff] [blame] | 33 | |
| 34 | struct uio_dmem_genirq_platdata { |
| 35 | struct uio_info *uioinfo; |
| 36 | spinlock_t lock; |
| 37 | unsigned long flags; |
| 38 | struct platform_device *pdev; |
| 39 | unsigned int dmem_region_start; |
| 40 | unsigned int num_dmem_regions; |
Damian Hobson-Garcia | 24fce61 | 2012-11-16 14:46:09 +0900 | [diff] [blame] | 41 | void *dmem_region_vaddr[MAX_UIO_MAPS]; |
Damian Hobson-Garcia | 0a0c3b5 | 2012-09-25 15:09:11 +0900 | [diff] [blame] | 42 | struct mutex alloc_lock; |
| 43 | unsigned int refcnt; |
| 44 | }; |
| 45 | |
| 46 | static int uio_dmem_genirq_open(struct uio_info *info, struct inode *inode) |
| 47 | { |
| 48 | struct uio_dmem_genirq_platdata *priv = info->priv; |
| 49 | struct uio_mem *uiomem; |
| 50 | int ret = 0; |
Damian Hobson-Garcia | 24fce61 | 2012-11-16 14:46:09 +0900 | [diff] [blame] | 51 | int dmem_region = priv->dmem_region_start; |
Damian Hobson-Garcia | 0a0c3b5 | 2012-09-25 15:09:11 +0900 | [diff] [blame] | 52 | |
| 53 | uiomem = &priv->uioinfo->mem[priv->dmem_region_start]; |
| 54 | |
| 55 | mutex_lock(&priv->alloc_lock); |
| 56 | while (!priv->refcnt && uiomem < &priv->uioinfo->mem[MAX_UIO_MAPS]) { |
| 57 | void *addr; |
| 58 | if (!uiomem->size) |
| 59 | break; |
| 60 | |
| 61 | addr = dma_alloc_coherent(&priv->pdev->dev, uiomem->size, |
| 62 | (dma_addr_t *)&uiomem->addr, GFP_KERNEL); |
| 63 | if (!addr) { |
Damian Hobson-Garcia | 87c4d1a | 2012-11-16 14:46:10 +0900 | [diff] [blame] | 64 | uiomem->addr = DMEM_MAP_ERROR; |
Damian Hobson-Garcia | 0a0c3b5 | 2012-09-25 15:09:11 +0900 | [diff] [blame] | 65 | } |
Damian Hobson-Garcia | 24fce61 | 2012-11-16 14:46:09 +0900 | [diff] [blame] | 66 | priv->dmem_region_vaddr[dmem_region++] = addr; |
Damian Hobson-Garcia | 0a0c3b5 | 2012-09-25 15:09:11 +0900 | [diff] [blame] | 67 | ++uiomem; |
| 68 | } |
| 69 | priv->refcnt++; |
| 70 | |
| 71 | mutex_unlock(&priv->alloc_lock); |
| 72 | /* Wait until the Runtime PM code has woken up the device */ |
| 73 | pm_runtime_get_sync(&priv->pdev->dev); |
| 74 | return ret; |
| 75 | } |
| 76 | |
| 77 | static int uio_dmem_genirq_release(struct uio_info *info, struct inode *inode) |
| 78 | { |
| 79 | struct uio_dmem_genirq_platdata *priv = info->priv; |
| 80 | struct uio_mem *uiomem; |
Damian Hobson-Garcia | 24fce61 | 2012-11-16 14:46:09 +0900 | [diff] [blame] | 81 | int dmem_region = priv->dmem_region_start; |
Damian Hobson-Garcia | 0a0c3b5 | 2012-09-25 15:09:11 +0900 | [diff] [blame] | 82 | |
| 83 | /* Tell the Runtime PM code that the device has become idle */ |
| 84 | pm_runtime_put_sync(&priv->pdev->dev); |
| 85 | |
| 86 | uiomem = &priv->uioinfo->mem[priv->dmem_region_start]; |
| 87 | |
| 88 | mutex_lock(&priv->alloc_lock); |
| 89 | |
| 90 | priv->refcnt--; |
| 91 | while (!priv->refcnt && uiomem < &priv->uioinfo->mem[MAX_UIO_MAPS]) { |
| 92 | if (!uiomem->size) |
| 93 | break; |
Damian Hobson-Garcia | 439926c | 2012-11-16 14:46:11 +0900 | [diff] [blame] | 94 | if (priv->dmem_region_vaddr[dmem_region]) { |
| 95 | dma_free_coherent(&priv->pdev->dev, uiomem->size, |
| 96 | priv->dmem_region_vaddr[dmem_region], |
| 97 | uiomem->addr); |
| 98 | } |
Damian Hobson-Garcia | 87c4d1a | 2012-11-16 14:46:10 +0900 | [diff] [blame] | 99 | uiomem->addr = DMEM_MAP_ERROR; |
Damian Hobson-Garcia | 439926c | 2012-11-16 14:46:11 +0900 | [diff] [blame] | 100 | ++dmem_region; |
Damian Hobson-Garcia | 0a0c3b5 | 2012-09-25 15:09:11 +0900 | [diff] [blame] | 101 | ++uiomem; |
| 102 | } |
| 103 | |
| 104 | mutex_unlock(&priv->alloc_lock); |
| 105 | return 0; |
| 106 | } |
| 107 | |
| 108 | static irqreturn_t uio_dmem_genirq_handler(int irq, struct uio_info *dev_info) |
| 109 | { |
| 110 | struct uio_dmem_genirq_platdata *priv = dev_info->priv; |
| 111 | |
| 112 | /* Just disable the interrupt in the interrupt controller, and |
| 113 | * remember the state so we can allow user space to enable it later. |
| 114 | */ |
| 115 | |
| 116 | if (!test_and_set_bit(0, &priv->flags)) |
| 117 | disable_irq_nosync(irq); |
| 118 | |
| 119 | return IRQ_HANDLED; |
| 120 | } |
| 121 | |
| 122 | static int uio_dmem_genirq_irqcontrol(struct uio_info *dev_info, s32 irq_on) |
| 123 | { |
| 124 | struct uio_dmem_genirq_platdata *priv = dev_info->priv; |
| 125 | unsigned long flags; |
| 126 | |
| 127 | /* Allow user space to enable and disable the interrupt |
| 128 | * in the interrupt controller, but keep track of the |
| 129 | * state to prevent per-irq depth damage. |
| 130 | * |
| 131 | * Serialize this operation to support multiple tasks. |
| 132 | */ |
| 133 | |
| 134 | spin_lock_irqsave(&priv->lock, flags); |
| 135 | if (irq_on) { |
| 136 | if (test_and_clear_bit(0, &priv->flags)) |
| 137 | enable_irq(dev_info->irq); |
| 138 | } else { |
| 139 | if (!test_and_set_bit(0, &priv->flags)) |
| 140 | disable_irq(dev_info->irq); |
| 141 | } |
| 142 | spin_unlock_irqrestore(&priv->lock, flags); |
| 143 | |
| 144 | return 0; |
| 145 | } |
| 146 | |
| 147 | static int uio_dmem_genirq_probe(struct platform_device *pdev) |
| 148 | { |
Jingoo Han | 31f5221 | 2013-08-30 13:11:56 +0900 | [diff] [blame] | 149 | struct uio_dmem_genirq_pdata *pdata = dev_get_platdata(&pdev->dev); |
Damian Hobson-Garcia | 0a0c3b5 | 2012-09-25 15:09:11 +0900 | [diff] [blame] | 150 | struct uio_info *uioinfo = &pdata->uioinfo; |
| 151 | struct uio_dmem_genirq_platdata *priv; |
| 152 | struct uio_mem *uiomem; |
| 153 | int ret = -EINVAL; |
| 154 | int i; |
| 155 | |
Damian Hobson-Garcia | d5185c4 | 2012-11-16 14:46:12 +0900 | [diff] [blame] | 156 | if (pdev->dev.of_node) { |
Damian Hobson-Garcia | 0a0c3b5 | 2012-09-25 15:09:11 +0900 | [diff] [blame] | 157 | int irq; |
| 158 | |
| 159 | /* alloc uioinfo for one device */ |
| 160 | uioinfo = kzalloc(sizeof(*uioinfo), GFP_KERNEL); |
| 161 | if (!uioinfo) { |
| 162 | ret = -ENOMEM; |
| 163 | dev_err(&pdev->dev, "unable to kmalloc\n"); |
| 164 | goto bad2; |
| 165 | } |
| 166 | uioinfo->name = pdev->dev.of_node->name; |
| 167 | uioinfo->version = "devicetree"; |
| 168 | |
| 169 | /* Multiple IRQs are not supported */ |
| 170 | irq = platform_get_irq(pdev, 0); |
| 171 | if (irq == -ENXIO) |
| 172 | uioinfo->irq = UIO_IRQ_NONE; |
| 173 | else |
| 174 | uioinfo->irq = irq; |
| 175 | } |
| 176 | |
| 177 | if (!uioinfo || !uioinfo->name || !uioinfo->version) { |
| 178 | dev_err(&pdev->dev, "missing platform_data\n"); |
| 179 | goto bad0; |
| 180 | } |
| 181 | |
| 182 | if (uioinfo->handler || uioinfo->irqcontrol || |
| 183 | uioinfo->irq_flags & IRQF_SHARED) { |
| 184 | dev_err(&pdev->dev, "interrupt configuration error\n"); |
| 185 | goto bad0; |
| 186 | } |
| 187 | |
| 188 | priv = kzalloc(sizeof(*priv), GFP_KERNEL); |
| 189 | if (!priv) { |
| 190 | ret = -ENOMEM; |
| 191 | dev_err(&pdev->dev, "unable to kmalloc\n"); |
| 192 | goto bad0; |
| 193 | } |
| 194 | |
| 195 | dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32)); |
| 196 | |
| 197 | priv->uioinfo = uioinfo; |
| 198 | spin_lock_init(&priv->lock); |
| 199 | priv->flags = 0; /* interrupt is enabled to begin with */ |
| 200 | priv->pdev = pdev; |
| 201 | mutex_init(&priv->alloc_lock); |
| 202 | |
| 203 | if (!uioinfo->irq) { |
| 204 | ret = platform_get_irq(pdev, 0); |
| 205 | if (ret < 0) { |
| 206 | dev_err(&pdev->dev, "failed to get IRQ\n"); |
Daeseok Youn | ca3c61f | 2014-05-22 09:46:12 +0900 | [diff] [blame] | 207 | goto bad1; |
Damian Hobson-Garcia | 0a0c3b5 | 2012-09-25 15:09:11 +0900 | [diff] [blame] | 208 | } |
| 209 | uioinfo->irq = ret; |
| 210 | } |
| 211 | uiomem = &uioinfo->mem[0]; |
| 212 | |
| 213 | for (i = 0; i < pdev->num_resources; ++i) { |
| 214 | struct resource *r = &pdev->resource[i]; |
| 215 | |
| 216 | if (r->flags != IORESOURCE_MEM) |
| 217 | continue; |
| 218 | |
| 219 | if (uiomem >= &uioinfo->mem[MAX_UIO_MAPS]) { |
| 220 | dev_warn(&pdev->dev, "device has more than " |
| 221 | __stringify(MAX_UIO_MAPS) |
| 222 | " I/O memory resources.\n"); |
| 223 | break; |
| 224 | } |
| 225 | |
| 226 | uiomem->memtype = UIO_MEM_PHYS; |
| 227 | uiomem->addr = r->start; |
| 228 | uiomem->size = resource_size(r); |
| 229 | ++uiomem; |
| 230 | } |
| 231 | |
Jan Viktorin | 4d31a25 | 2016-05-17 11:22:17 +0200 | [diff] [blame] | 232 | priv->dmem_region_start = uiomem - &uioinfo->mem[0]; |
Damian Hobson-Garcia | 0a0c3b5 | 2012-09-25 15:09:11 +0900 | [diff] [blame] | 233 | priv->num_dmem_regions = pdata->num_dynamic_regions; |
| 234 | |
| 235 | for (i = 0; i < pdata->num_dynamic_regions; ++i) { |
| 236 | if (uiomem >= &uioinfo->mem[MAX_UIO_MAPS]) { |
| 237 | dev_warn(&pdev->dev, "device has more than " |
| 238 | __stringify(MAX_UIO_MAPS) |
| 239 | " dynamic and fixed memory regions.\n"); |
| 240 | break; |
| 241 | } |
| 242 | uiomem->memtype = UIO_MEM_PHYS; |
Damian Hobson-Garcia | 87c4d1a | 2012-11-16 14:46:10 +0900 | [diff] [blame] | 243 | uiomem->addr = DMEM_MAP_ERROR; |
Damian Hobson-Garcia | 0a0c3b5 | 2012-09-25 15:09:11 +0900 | [diff] [blame] | 244 | uiomem->size = pdata->dynamic_region_sizes[i]; |
| 245 | ++uiomem; |
| 246 | } |
| 247 | |
| 248 | while (uiomem < &uioinfo->mem[MAX_UIO_MAPS]) { |
| 249 | uiomem->size = 0; |
| 250 | ++uiomem; |
| 251 | } |
| 252 | |
| 253 | /* This driver requires no hardware specific kernel code to handle |
| 254 | * interrupts. Instead, the interrupt handler simply disables the |
| 255 | * interrupt in the interrupt controller. User space is responsible |
| 256 | * for performing hardware specific acknowledge and re-enabling of |
| 257 | * the interrupt in the interrupt controller. |
| 258 | * |
| 259 | * Interrupt sharing is not supported. |
| 260 | */ |
| 261 | |
| 262 | uioinfo->handler = uio_dmem_genirq_handler; |
| 263 | uioinfo->irqcontrol = uio_dmem_genirq_irqcontrol; |
| 264 | uioinfo->open = uio_dmem_genirq_open; |
| 265 | uioinfo->release = uio_dmem_genirq_release; |
| 266 | uioinfo->priv = priv; |
| 267 | |
| 268 | /* Enable Runtime PM for this device: |
| 269 | * The device starts in suspended state to allow the hardware to be |
| 270 | * turned off by default. The Runtime PM bus code should power on the |
| 271 | * hardware and enable clocks at open(). |
| 272 | */ |
| 273 | pm_runtime_enable(&pdev->dev); |
| 274 | |
| 275 | ret = uio_register_device(&pdev->dev, priv->uioinfo); |
| 276 | if (ret) { |
| 277 | dev_err(&pdev->dev, "unable to register uio device\n"); |
Daeseok Youn | ca3c61f | 2014-05-22 09:46:12 +0900 | [diff] [blame] | 278 | pm_runtime_disable(&pdev->dev); |
Damian Hobson-Garcia | 0a0c3b5 | 2012-09-25 15:09:11 +0900 | [diff] [blame] | 279 | goto bad1; |
| 280 | } |
| 281 | |
| 282 | platform_set_drvdata(pdev, priv); |
| 283 | return 0; |
| 284 | bad1: |
| 285 | kfree(priv); |
Damian Hobson-Garcia | 0a0c3b5 | 2012-09-25 15:09:11 +0900 | [diff] [blame] | 286 | bad0: |
| 287 | /* kfree uioinfo for OF */ |
| 288 | if (pdev->dev.of_node) |
| 289 | kfree(uioinfo); |
| 290 | bad2: |
| 291 | return ret; |
| 292 | } |
| 293 | |
| 294 | static int uio_dmem_genirq_remove(struct platform_device *pdev) |
| 295 | { |
| 296 | struct uio_dmem_genirq_platdata *priv = platform_get_drvdata(pdev); |
| 297 | |
| 298 | uio_unregister_device(priv->uioinfo); |
| 299 | pm_runtime_disable(&pdev->dev); |
| 300 | |
| 301 | priv->uioinfo->handler = NULL; |
| 302 | priv->uioinfo->irqcontrol = NULL; |
| 303 | |
| 304 | /* kfree uioinfo for OF */ |
| 305 | if (pdev->dev.of_node) |
| 306 | kfree(priv->uioinfo); |
| 307 | |
| 308 | kfree(priv); |
| 309 | return 0; |
| 310 | } |
| 311 | |
| 312 | static int uio_dmem_genirq_runtime_nop(struct device *dev) |
| 313 | { |
| 314 | /* Runtime PM callback shared between ->runtime_suspend() |
| 315 | * and ->runtime_resume(). Simply returns success. |
| 316 | * |
| 317 | * In this driver pm_runtime_get_sync() and pm_runtime_put_sync() |
| 318 | * are used at open() and release() time. This allows the |
| 319 | * Runtime PM code to turn off power to the device while the |
| 320 | * device is unused, ie before open() and after release(). |
| 321 | * |
| 322 | * This Runtime PM callback does not need to save or restore |
| 323 | * any registers since user space is responsbile for hardware |
| 324 | * register reinitialization after open(). |
| 325 | */ |
| 326 | return 0; |
| 327 | } |
| 328 | |
| 329 | static const struct dev_pm_ops uio_dmem_genirq_dev_pm_ops = { |
| 330 | .runtime_suspend = uio_dmem_genirq_runtime_nop, |
| 331 | .runtime_resume = uio_dmem_genirq_runtime_nop, |
| 332 | }; |
| 333 | |
| 334 | #ifdef CONFIG_OF |
| 335 | static const struct of_device_id uio_of_genirq_match[] = { |
| 336 | { /* empty for now */ }, |
| 337 | }; |
| 338 | MODULE_DEVICE_TABLE(of, uio_of_genirq_match); |
Damian Hobson-Garcia | 0a0c3b5 | 2012-09-25 15:09:11 +0900 | [diff] [blame] | 339 | #endif |
| 340 | |
| 341 | static struct platform_driver uio_dmem_genirq = { |
| 342 | .probe = uio_dmem_genirq_probe, |
| 343 | .remove = uio_dmem_genirq_remove, |
| 344 | .driver = { |
| 345 | .name = DRIVER_NAME, |
Damian Hobson-Garcia | 0a0c3b5 | 2012-09-25 15:09:11 +0900 | [diff] [blame] | 346 | .pm = &uio_dmem_genirq_dev_pm_ops, |
Sachin Kamat | 07779711 | 2013-06-19 10:02:47 +0530 | [diff] [blame] | 347 | .of_match_table = of_match_ptr(uio_of_genirq_match), |
Damian Hobson-Garcia | 0a0c3b5 | 2012-09-25 15:09:11 +0900 | [diff] [blame] | 348 | }, |
| 349 | }; |
| 350 | |
| 351 | module_platform_driver(uio_dmem_genirq); |
| 352 | |
| 353 | MODULE_AUTHOR("Damian Hobson-Garcia"); |
| 354 | MODULE_DESCRIPTION("Userspace I/O platform driver with dynamic memory."); |
| 355 | MODULE_LICENSE("GPL v2"); |
| 356 | MODULE_ALIAS("platform:" DRIVER_NAME); |