/*
* Copyright (C) 2007 Google, Inc.
* Copyright (C) 2011 Intel, Inc.
* Copyright (C) 2013 Intel, Inc.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/io.h>
#define PDEV_BUS_OP_DONE (0x00)
#define PDEV_BUS_OP_REMOVE_DEV (0x04)
#define PDEV_BUS_OP_ADD_DEV (0x08)
#define PDEV_BUS_OP_INIT (0x00)
#define PDEV_BUS_OP (0x00)
#define PDEV_BUS_GET_NAME (0x04)
#define PDEV_BUS_NAME_LEN (0x08)
#define PDEV_BUS_ID (0x0c)
#define PDEV_BUS_IO_BASE (0x10)
#define PDEV_BUS_IO_SIZE (0x14)
#define PDEV_BUS_IRQ (0x18)
#define PDEV_BUS_IRQ_COUNT (0x1c)
struct pdev_bus_dev {
struct list_head list;
struct platform_device pdev;
struct resource resources[0];
};
static void goldfish_pdev_worker(struct work_struct *work);
static void __iomem *pdev_bus_base;
static unsigned long pdev_bus_addr;
static unsigned long pdev_bus_len;
static u32 pdev_bus_irq;
static LIST_HEAD(pdev_bus_new_devices);
static LIST_HEAD(pdev_bus_registered_devices);
static LIST_HEAD(pdev_bus_removed_devices);
static DECLARE_WORK(pdev_bus_worker, goldfish_pdev_worker);
static void goldfish_pdev_worker(struct work_struct *work)
{
int ret;
struct pdev_bus_dev *pos, *n;
list_for_each_entry_safe(pos, n, &pdev_bus_removed_devices, list) {
list_del(&pos->list);
platform_device_unregister(&pos->pdev);
kfree(pos);
}
list_for_each_entry_safe(pos, n, &pdev_bus_new_devices, list) {
list_del(&pos->list);
ret = platform_device_register(&pos->pdev);
if (ret)
pr_err("goldfish_pdev_worker failed to register device, %s\n",
pos->pdev.name);
list_add_tail(&pos->list, &pdev_bus_registered_devices);
}
}
static void goldfish_pdev_remove(void)
{
struct pdev_bus_dev *pos, *n;
u32 base;
base = readl(pdev_bus_base + PDEV_BUS_IO_BASE);
list_for_each_entry_safe(pos, n, &pdev_bus_new_devices, list) {
if (pos->resources[0].start == base) {
list_del(&pos->list);
kfree(pos);
return;
}
}
list_for_each_entry_safe(pos, n, &pdev_bus_registered_devices, list) {
if (pos->resources[0].start == base) {
list_del(&pos->list);
list_add_tail(&pos->list, &pdev_bus_removed_devices);
schedule_work(&pdev_bus_worker);
return;
}
};
pr_err("goldfish_pdev_remove could not find device at %x\n", base);
}
static int goldfish_new_pdev(void)
{
struct pdev_bus_dev *dev;
u32 name_len;
u32 irq = -1, irq_count;
int resource_count = 2;
u32 base;
char *name;
base = readl(pdev_bus_base + PDEV_BUS_IO_BASE);
irq_count = readl(pdev_bus_base + PDEV_BUS_IRQ_COUNT);
name_len = readl(pdev_bus_base + PDEV_BUS_NAME_LEN);
if (irq_count)
resource_count++;
dev = kzalloc(sizeof(*dev) +
sizeof(struct resource) * resource_count +
name_len + 1 + sizeof(*dev->pdev.dev.dma_mask), GFP_ATOMIC);
if (dev == NULL)
return -ENOMEM;
dev->pdev.num_resources = resource_count;
dev->pdev.resource = (struct resource *)(dev + 1);
dev->pdev.name = name = (char *)(dev->pdev.resource + resource_count);
dev->pdev.dev.coherent_dma_mask = ~0;
dev->pdev.dev.dma_mask = (void *)(dev->pdev.name + name_len + 1);
*dev->pdev.dev.dma_mask = ~0;
writel((unsigned long)name, pdev_bus_base + PDEV_BUS_GET_NAME);
name[name_len] = '\0';
dev->pdev.id = readl(pdev_bus_base + PDEV_BUS_ID);
dev->pdev.resource[0].start = base;
dev->pdev.resource[0].end = base +
readl(pdev_bus_base + PDEV_BUS_IO_SIZE) - 1;
dev->pdev.resource[0].flags = IORESOURCE_MEM;
if (irq_count) {
irq = readl(pdev_bus_base + PDEV_BUS_IRQ);
dev->pdev.resource[1].start = irq;
dev->pdev.resource[1].end = irq + irq_count - 1;
dev->pdev.resource[1].flags = IORESOURCE_IRQ;
}
pr_debug("goldfish_new_pdev %s at %x irq %d\n", name, base, irq);
list_add_tail(&dev->list, &pdev_bus_new_devices);
schedule_work(&pdev_bus_worker);
return 0;
}
static irqreturn_t goldfish_pdev_bus_interrupt(int irq, void *dev_id)
{
irqreturn_t ret = IRQ_NONE;
while (1) {
u32 op = readl(pdev_bus_base + PDEV_BUS_OP);
switch (op) {
case PDEV_BUS_OP_DONE:
return IRQ_NONE;
case PDEV_BUS_OP_REMOVE_DEV:
goldfish_pdev_remove();
break;
case PDEV_BUS_OP_ADD_DEV:
goldfish_new_pdev();
break;
}
ret = IRQ_HANDLED;
}
return ret;
}
static int goldfish_pdev_bus_probe(struct platform_device *pdev)
{
int ret;
struct resource *r;
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (r == NULL)
return -EINVAL;
pdev_bus_addr = r->start;
pdev_bus_len = resource_size(r);
if (request_mem_region(pdev_bus_addr, pdev_bus_len, "goldfish")) {
dev_err(&pdev->dev, "unable to reserve Goldfish MMIO.\n");
return -EBUSY;
}
pdev_bus_base = ioremap(pdev_bus_addr, pdev_bus_len);
if (pdev_bus_base == NULL) {
ret = -ENOMEM;
dev_err(&pdev->dev, "unable to map Goldfish MMIO.\n");
goto free_resources;
}
r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (r == NULL) {
ret = -ENOENT;
goto free_map;
}
pdev_bus_irq = r->start;
ret = request_irq(pdev_bus_irq, goldfish_pdev_bus_interrupt,
IRQF_SHARED, "goldfish_pdev_bus", pdev);
if (ret) {
dev_err(&pdev->dev, "unable to request Goldfish IRQ\n");
goto free_map;
}
writel(PDEV_BUS_OP_INIT, pdev_bus_base + PDEV_BUS_OP);
return 0;
free_map:
iounmap(pdev_bus_base);
free_resources:
release_mem_region(pdev_bus_addr, pdev_bus_len);
return ret;
}
static int goldfish_pdev_bus_remove(struct platform_device *pdev)
{
iounmap(pdev_bus_base);
free_irq(pdev_bus_irq, pdev);
release_mem_region(pdev_bus_addr, pdev_bus_len);
return 0;
}
static struct platform_driver goldfish_pdev_bus_driver = {
.probe = goldfish_pdev_bus_probe,
.remove = goldfish_pdev_bus_remove,
.driver = {
.name = "goldfish_pdev_bus"
}
};
module_platform_driver(goldfish_pdev_bus_driver);
