video: tegra: host: use platform bus/driver/device

- this commit replaces the custom nvhost bus/driver/device
with platform bus/driver/device
- this is in preparation to add DT support
- following is the list of notable changes done:

1. chip_ops: The per SoC differences is encapsulated by chip_ops structure.
With nvhost_bus:
- It is hidden in nvhost_bus and exposed APIs to rest of the code.
These APIs land up in correct implementation for current SoC.
With platform_bus:
- I had to make this global and adjust the API accordingly.

2. nvhost_device
With nvhost_bus:
- The struct nvhost_device encapsulates both Linux device driver parts
as well as tegra specific parts.
With platform_bus:
- I had to move the current nvhost_device as a platform_data
for each platform_device. For this I renamed the struct nvhost_device
to struct nvhost_device_data.
- Also, since nvhost_driver is gone, I had to move all the
function pointers in it to struct nvhost_device_data.

3. Device specific private data: Host1x master device has its own
static data (called nvhost_master) which stores the per SoC
sync-point, IRQ info etc.
With nvhost_bus:
- This was stored as device specific platform_data.
With platform_bus:
- The device specific platform_data is now struct nvhost_device_data
(as mentioned above).
- I need to keep it common for all the devices whose code is
part of host1x directory, so that other parts of code that need per-device
info have a unique interface of platform_get_drvdata.
- As a result, I had to add a void * field in struct nvhost_device_data
which now holds per-device specific data and expose APIs to get/set this data.
- As of now, only host1x master parent device code uses this.

4. Per SoC device names:
With nvhost_bus:
- Per SoC device name is SAME for all the SoCs.
- The correct driver get linked to this device via the concept of id_table.
This id_table allows us to connect multiple devices to single driver code
and pass appropriate function pointer specific to SoC (you can check gr3d.c for details).
With platform_bus:
- The id_table usage of platform_bus is different from above.
- To adhere to its need, I had to append the per-SoC device name
with a version field (so gr3d for t20 became gr3d01, for t30 became gr3d02 etc).
- I adjusted the correct names in _probe of such devices.
Also, I adjusted the node names exposed to user space (/dev/host-gr3d etc)
to be consistent across SoCs.
- But this fails for the sysfs entries created by device registration code
of Linux, since during this time the _probe is not called.
So, device name is still appended with version field.

5. Per SoC device registration function: tegraXXX_register_host1x_devices
is the per SoC specific APIs which is called by board-file to register
the host1x and client devices. Host1x has strict requirements for the
parent->child relations i.e. any client of host1x device should have the
parent set properly BEFORE device registration.
With nvhost_bus:
- Setting of parent was taken care by nvhost_device_register call and other helpers.
With platform_bus:
- It is not possible to change parent till _probe of client device returns
(meaning not much of control in our hand). The device driver core,
takes a mutex lock of parent BEFORE calling _probe to avoid changing parent during _probe.
- So, to set correct parent, I changed the return type of
tegraXXX_register_host1x_devices to return pointer to master host1x parent device.

6. platform_get_drvdata calls:
With nvhost_bus:
- Only host1x master parent calls this.
With platform_bus:
- Almost all the common code ends up calling this.
Fortunately, we had designed the APIs such that they take nvhost_device * as argument.
So changing them to platform_device * is in a way easy.

7. Device list: The debug-fs dump code & module-reg-read-write
functionality rely on having a list of host1x devices registered currently.
With nvhost_bus:
- This is readily available since struct bus_type of Linux holds this list.
Moreover, it provides an iterators to access this list.
With platform_bus:
- Since it holds large number of devices in system, it is inefficient
to use the above iterators. Also, it is difficult to have a common matching
criteria for all the devices who have different platform_data.
- As a result, I had to add a simple list using Linux kernel's list implementation.
It holds the list of devices which have their code within host1x directory
and actually use channels (remember tegra-dc and nvavp are outside
host1x code && do not use physical channels they only need sync-point
and host1x hardware alive when they are alive).
I also had to provide 2 iterators one which is used for
module-reg-read-write and other for debug-fs dump.

8. I changed how tegra-dc and nvavp called the host1x externally exposed APIs
(such APIs end with _ext). In current code, they know little too much of
host1x code internals. I now changed to make them independent of host1x internal
implementation and structure know-how. They now simply send their own
platform_device * to the external visible APIs and these APIs
ensures that the call ends up in correct function call.

bug 1041377

Change-Id: I9cd4d506e6f3bde805923ce7c7bbbd37c9ec13c4
Signed-off-by: Mayuresh Kulkarni <mkulkarni@nvidia.com>
Reviewed-on: http://git-master/r/131403
Reviewed-by: Simone Willett <swillett@nvidia.com>
Tested-by: Simone Willett <swillett@nvidia.com>

1 files changed, 20 insertions, 21 deletions

diff --git a/drivers/media/video/tegra/nvavp/nvavp_dev.c b/drivers/media/video/tegra/nvavp/nvavp_dev.c
index 01bb253f2b9a..704cf8703e9f 100644
--- a/drivers/media/video/tegra/nvavp/nvavp_dev.c
+++ b/drivers/media/video/tegra/nvavp/nvavp_dev.c
@@ -144,7 +144,7 @@ struct nvavp_info {
 	u32				syncpt_id;
 	u32				syncpt_value;
 
-	struct nvhost_device		*nvhost_dev;
+	struct platform_device		*nvhost_dev;
 	struct miscdevice		video_misc_dev;
 #if defined(CONFIG_TEGRA_NVAVP_AUDIO)
 	struct miscdevice		audio_misc_dev;
@@ -295,7 +295,7 @@ static int nvavp_unpowergate_vde(struct nvavp_info *nvavp)
 static void nvavp_clks_enable(struct nvavp_info *nvavp)
 {
 	if (nvavp->clk_enabled++ == 0) {
-		nvhost_module_busy_ext(nvhost_get_parent(nvavp->nvhost_dev));
+		nvhost_module_busy_ext(nvavp->nvhost_dev);
 		clk_prepare_enable(nvavp->bsev_clk);
 		clk_prepare_enable(nvavp->vde_clk);
 		nvavp_unpowergate_vde(nvavp);
@@ -316,7 +316,7 @@ static void nvavp_clks_disable(struct nvavp_info *nvavp)
 		clk_set_rate(nvavp->emc_clk, 0);
 		clk_set_rate(nvavp->sclk, 0);
 		nvavp_powergate_vde(nvavp);
-		nvhost_module_idle_ext(nvhost_get_parent(nvavp->nvhost_dev));
+		nvhost_module_idle_ext(nvavp->nvhost_dev);
 		dev_dbg(&nvavp->nvhost_dev->dev, "%s: resetting emc_clk "
 				"and sclk\n", __func__);
 	}
@@ -1533,16 +1533,16 @@ static const struct file_operations tegra_audio_nvavp_fops = {
 #endif
 
 static ssize_t boost_sclk_show(struct device *dev,
-		struct device_attribute *attr, char *buf)
+	struct device_attribute *attr, char *buf)
 {
 	return snprintf(buf, PAGE_SIZE, "%d\n", boost_sclk);
 }
 
 static ssize_t boost_sclk_store(struct device *dev,
-		struct device_attribute *attr, const char *buf, size_t count)
+	struct device_attribute *attr, const char *buf, size_t count)
 {
-	struct nvhost_device *ndev = to_nvhost_device(dev);
-	struct nvavp_info *nvavp = nvhost_get_drvdata(ndev);
+	struct platform_device *ndev = to_platform_device(dev);
+	struct nvavp_info *nvavp = platform_get_drvdata(ndev);
 	unsigned long val = 0;
 
 	if (kstrtoul(buf, 10, &val) < 0)
@@ -1558,10 +1558,9 @@ static ssize_t boost_sclk_store(struct device *dev,
 	return count;
 }
 
-DEVICE_ATTR(boost_sclk, S_IRUGO|S_IWUSR, boost_sclk_show, boost_sclk_store);
+DEVICE_ATTR(boost_sclk, S_IRUGO | S_IWUSR, boost_sclk_show, boost_sclk_store);
 
-static int tegra_nvavp_probe(struct nvhost_device *ndev,
-	struct nvhost_device_id *id_table)
+static int tegra_nvavp_probe(struct platform_device *ndev)
 {
 	struct nvavp_info *nvavp;
 	int irq;
@@ -1569,7 +1568,7 @@ static int tegra_nvavp_probe(struct nvhost_device *ndev,
 	u32 iovmm_addr;
 	int ret = 0, channel_id;
 
-	irq = nvhost_get_irq_byname(ndev, "mbox_from_nvavp_pending");
+	irq = platform_get_irq_byname(ndev, "mbox_from_nvavp_pending");
 	if (irq < 0) {
 		dev_err(&ndev->dev, "invalid nvhost data\n");
 		return -EINVAL;
@@ -1766,8 +1765,8 @@ static int tegra_nvavp_probe(struct nvhost_device *ndev,
 	}
 	disable_irq(nvavp->mbox_from_avp_pend_irq);
 
-	nvhost_set_drvdata(ndev, nvavp);
 	nvavp->nvhost_dev = ndev;
+	platform_set_drvdata(ndev, nvavp);
 
 	device_create_file(&ndev->dev, &dev_attr_boost_sclk);
 
@@ -1813,9 +1812,9 @@ err_get_syncpt:
 	return ret;
 }
 
-static int tegra_nvavp_remove(struct nvhost_device *ndev)
+static int tegra_nvavp_remove(struct platform_device *ndev)
 {
-	struct nvavp_info *nvavp = nvhost_get_drvdata(ndev);
+	struct nvavp_info *nvavp = platform_get_drvdata(ndev);
 
 	if (!nvavp)
 		return 0;
@@ -1853,9 +1852,9 @@ static int tegra_nvavp_remove(struct nvhost_device *ndev)
 }
 
 #ifdef CONFIG_PM
-static int tegra_nvavp_suspend(struct nvhost_device *ndev, pm_message_t state)
+static int tegra_nvavp_suspend(struct platform_device *ndev, pm_message_t state)
 {
-	struct nvavp_info *nvavp = nvhost_get_drvdata(ndev);
+	struct nvavp_info *nvavp = platform_get_drvdata(ndev);
 	int ret = 0;
 
 	mutex_lock(&nvavp->open_lock);
@@ -1885,9 +1884,9 @@ static int tegra_nvavp_suspend(struct nvhost_device *ndev, pm_message_t state)
 	return ret;
 }
 
-static int tegra_nvavp_resume(struct nvhost_device *ndev)
+static int tegra_nvavp_resume(struct platform_device *ndev)
 {
-	struct nvavp_info *nvavp = nvhost_get_drvdata(ndev);
+	struct nvavp_info *nvavp = platform_get_drvdata(ndev);
 
 	mutex_lock(&nvavp->open_lock);
 
@@ -1903,7 +1902,7 @@ static int tegra_nvavp_resume(struct nvhost_device *ndev)
 }
 #endif
 
-static struct nvhost_driver tegra_nvavp_driver = {
+static struct platform_driver tegra_nvavp_driver = {
 	.driver	= {
 		.name	= TEGRA_NVAVP_NAME,
 		.owner	= THIS_MODULE,
@@ -1918,12 +1917,12 @@ static struct nvhost_driver tegra_nvavp_driver = {
 
 static int __init tegra_nvavp_init(void)
 {
-	return nvhost_driver_register(&tegra_nvavp_driver);
+	return platform_driver_register(&tegra_nvavp_driver);
 }
 
 static void __exit tegra_nvavp_exit(void)
 {
-	nvhost_driver_unregister(&tegra_nvavp_driver);
+	platform_driver_unregister(&tegra_nvavp_driver);
 }
 
 module_init(tegra_nvavp_init);