drivers/platform/goldfish/pdev_bus.c

   1 /*
   2  * Copyright (C) 2007 Google, Inc.
   3  * Copyright (C) 2011 Intel, Inc.
   4  * Copyright (C) 2013 Intel, Inc.
   5  *
   6  * This software is licensed under the terms of the GNU General Public
   7  * License version 2, as published by the Free Software Foundation, and
   8  * may be copied, distributed, and modified under those terms.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  */
  16
  17 #include <linux/kernel.h>
  18 #include <linux/init.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/irq.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/slab.h>
  23 #include <linux/io.h>
  24
  25 #define PDEV_BUS_OP_DONE        (0x00)
  26 #define PDEV_BUS_OP_REMOVE_DEV  (0x04)
  27 #define PDEV_BUS_OP_ADD_DEV     (0x08)
  28
  29 #define PDEV_BUS_OP_INIT        (0x00)
  30
  31 #define PDEV_BUS_OP             (0x00)
  32 #define PDEV_BUS_GET_NAME       (0x04)
  33 #define PDEV_BUS_NAME_LEN       (0x08)
  34 #define PDEV_BUS_ID             (0x0c)
  35 #define PDEV_BUS_IO_BASE        (0x10)
  36 #define PDEV_BUS_IO_SIZE        (0x14)
  37 #define PDEV_BUS_IRQ            (0x18)
  38 #define PDEV_BUS_IRQ_COUNT      (0x1c)
  39 #define PDEV_BUS_GET_NAME_HIGH  (0x20)
  40
  41 struct pdev_bus_dev {
  42         struct list_head list;
  43         struct platform_device pdev;
  44         struct resource resources[0];
  45 };
  46
  47 static void goldfish_pdev_worker(struct work_struct *work);
  48
  49 static void __iomem *pdev_bus_base;
  50 static unsigned long pdev_bus_addr;
  51 static unsigned long pdev_bus_len;
  52 static u32 pdev_bus_irq;
  53 static LIST_HEAD(pdev_bus_new_devices);
  54 static LIST_HEAD(pdev_bus_registered_devices);
  55 static LIST_HEAD(pdev_bus_removed_devices);
  56 static DECLARE_WORK(pdev_bus_worker, goldfish_pdev_worker);
  57
  58
  59 static void goldfish_pdev_worker(struct work_struct *work)
  60 {
  61         int ret;
  62         struct pdev_bus_dev *pos, *n;
  63
  64         list_for_each_entry_safe(pos, n, &pdev_bus_removed_devices, list) {
  65                 list_del(&pos->list);
  66                 platform_device_unregister(&pos->pdev);
  67                 kfree(pos);
  68         }
  69         list_for_each_entry_safe(pos, n, &pdev_bus_new_devices, list) {
  70                 list_del(&pos->list);
  71                 ret = platform_device_register(&pos->pdev);
  72                 if (ret)
  73                         pr_err("goldfish_pdev_worker failed to register device, %s\n",
  74                                                                 pos->pdev.name);
  75                 list_add_tail(&pos->list, &pdev_bus_registered_devices);
  76         }
  77 }
  78
  79 static void goldfish_pdev_remove(void)
  80 {
  81         struct pdev_bus_dev *pos, *n;
  82         u32 base;
  83
  84         base = readl(pdev_bus_base + PDEV_BUS_IO_BASE);
  85
  86         list_for_each_entry_safe(pos, n, &pdev_bus_new_devices, list) {
  87                 if (pos->resources[0].start == base) {
  88                         list_del(&pos->list);
  89                         kfree(pos);
  90                         return;
  91                 }
  92         }
  93         list_for_each_entry_safe(pos, n, &pdev_bus_registered_devices, list) {
  94                 if (pos->resources[0].start == base) {
  95                         list_del(&pos->list);
  96                         list_add_tail(&pos->list, &pdev_bus_removed_devices);
  97                         schedule_work(&pdev_bus_worker);
  98                         return;
  99                 }
 100         };
 101         pr_err("goldfish_pdev_remove could not find device at %x\n", base);
 102 }
 103
 104 static int goldfish_new_pdev(void)
 105 {
 106         struct pdev_bus_dev *dev;
 107         u32 name_len;
 108         u32 irq = -1, irq_count;
 109         int resource_count = 2;
 110         u32 base;
 111         char *name;
 112
 113         base = readl(pdev_bus_base + PDEV_BUS_IO_BASE);
 114
 115         irq_count = readl(pdev_bus_base + PDEV_BUS_IRQ_COUNT);
 116         name_len = readl(pdev_bus_base + PDEV_BUS_NAME_LEN);
 117         if (irq_count)
 118                 resource_count++;
 119
 120         dev = kzalloc(sizeof(*dev) +
 121                 sizeof(struct resource) * resource_count +
 122                 name_len + 1 + sizeof(*dev->pdev.dev.dma_mask), GFP_ATOMIC);
 123         if (dev == NULL)
 124                 return -ENOMEM;
 125
 126         dev->pdev.num_resources = resource_count;
 127         dev->pdev.resource = (struct resource *)(dev + 1);
 128         dev->pdev.name = name = (char *)(dev->pdev.resource + resource_count);
 129         dev->pdev.dev.coherent_dma_mask = ~0;
 130         dev->pdev.dev.dma_mask = (void *)(dev->pdev.name + name_len + 1);
 131         *dev->pdev.dev.dma_mask = ~0;
 132
 133 #ifdef CONFIG_64BIT
 134         writel((u32)((u64)name>>32), pdev_bus_base + PDEV_BUS_GET_NAME_HIGH);
 135 #endif
 136         writel((u32)(unsigned long)name, pdev_bus_base + PDEV_BUS_GET_NAME);
 137         name[name_len] = '\0';
 138         dev->pdev.id = readl(pdev_bus_base + PDEV_BUS_ID);
 139         dev->pdev.resource[0].start = base;
 140         dev->pdev.resource[0].end = base +
 141                                 readl(pdev_bus_base + PDEV_BUS_IO_SIZE) - 1;
 142         dev->pdev.resource[0].flags = IORESOURCE_MEM;
 143         if (irq_count) {
 144                 irq = readl(pdev_bus_base + PDEV_BUS_IRQ);
 145                 dev->pdev.resource[1].start = irq;
 146                 dev->pdev.resource[1].end = irq + irq_count - 1;
 147                 dev->pdev.resource[1].flags = IORESOURCE_IRQ;
 148         }
 149
 150         pr_debug("goldfish_new_pdev %s at %x irq %d\n", name, base, irq);
 151         list_add_tail(&dev->list, &pdev_bus_new_devices);
 152         schedule_work(&pdev_bus_worker);
 153
 154         return 0;
 155 }
 156
 157 static irqreturn_t goldfish_pdev_bus_interrupt(int irq, void *dev_id)
 158 {
 159         irqreturn_t ret = IRQ_NONE;
 160
 161         while (1) {
 162                 u32 op = readl(pdev_bus_base + PDEV_BUS_OP);
 163
 164                 switch (op) {
 165                 case PDEV_BUS_OP_REMOVE_DEV:
 166                         goldfish_pdev_remove();
 167                         ret = IRQ_HANDLED;
 168                         break;
 169
 170                 case PDEV_BUS_OP_ADD_DEV:
 171                         goldfish_new_pdev();
 172                         ret = IRQ_HANDLED;
 173                         break;
 174
 175                 case PDEV_BUS_OP_DONE:
 176                 default:
 177                         return ret;
 178                 }
 179         }
 180 }
 181
 182 static int goldfish_pdev_bus_probe(struct platform_device *pdev)
 183 {
 184         int ret;
 185         struct resource *r;
 186
 187         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 188         if (r == NULL)
 189                 return -EINVAL;
 190
 191         pdev_bus_addr = r->start;
 192         pdev_bus_len = resource_size(r);
 193
 194         pdev_bus_base = ioremap(pdev_bus_addr, pdev_bus_len);
 195         if (pdev_bus_base == NULL) {
 196                 ret = -ENOMEM;
 197                 dev_err(&pdev->dev, "unable to map Goldfish MMIO.\n");
 198                 goto free_resources;
 199         }
 200
 201         r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 202         if (r == NULL) {
 203                 ret = -ENOENT;
 204                 goto free_map;
 205         }
 206
 207         pdev_bus_irq = r->start;
 208
 209         ret = request_irq(pdev_bus_irq, goldfish_pdev_bus_interrupt,
 210                                 IRQF_SHARED, "goldfish_pdev_bus", pdev);
 211         if (ret) {
 212                 dev_err(&pdev->dev, "unable to request Goldfish IRQ\n");
 213                 goto free_map;
 214         }
 215
 216         writel(PDEV_BUS_OP_INIT, pdev_bus_base + PDEV_BUS_OP);
 217         return 0;
 218
 219 free_map:
 220         iounmap(pdev_bus_base);
 221 free_resources:
 222         release_mem_region(pdev_bus_addr, pdev_bus_len);
 223         return ret;
 224 }
 225
 226 static struct platform_driver goldfish_pdev_bus_driver = {
 227         .probe = goldfish_pdev_bus_probe,
 228         .driver = {
 229                 .name = "goldfish_pdev_bus"
 230         }
 231 };
 232 builtin_platform_driver(goldfish_pdev_bus_driver);