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/* SPDX-License-Identifier: GPL-2.0+ */
#include <linux/init.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/io.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/fs.h>
#include <linux/rwsem.h>
#include "kpc_dma_driver.h"
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Matt.Sickler@daktronics.com");
#define KPC_DMA_CHAR_MAJOR UNNAMED_MAJOR
#define KPC_DMA_NUM_MINORS BIT(MINORBITS)
static DEFINE_MUTEX(kpc_dma_mtx);
static int assigned_major_num;
static LIST_HEAD(kpc_dma_list);
/********** kpc_dma_list list management **********/
struct kpc_dma_device *kpc_dma_lookup_device(int minor)
{
struct kpc_dma_device *c;
mutex_lock(&kpc_dma_mtx);
list_for_each_entry(c, &kpc_dma_list, list) {
if (c->pldev->id == minor)
goto out;
}
c = NULL; // not-found case
out:
mutex_unlock(&kpc_dma_mtx);
return c;
}
static void kpc_dma_add_device(struct kpc_dma_device *ldev)
{
mutex_lock(&kpc_dma_mtx);
list_add(&ldev->list, &kpc_dma_list);
mutex_unlock(&kpc_dma_mtx);
}
static void kpc_dma_del_device(struct kpc_dma_device *ldev)
{
mutex_lock(&kpc_dma_mtx);
list_del(&ldev->list);
mutex_unlock(&kpc_dma_mtx);
}
/********** SysFS Attributes **********/
static ssize_t show_engine_regs(struct device *dev, struct device_attribute *attr, char *buf)
{
struct kpc_dma_device *ldev;
struct platform_device *pldev = to_platform_device(dev);
if (!pldev)
return 0;
ldev = platform_get_drvdata(pldev);
if (!ldev)
return 0;
return scnprintf(buf, PAGE_SIZE,
"EngineControlStatus = 0x%08x\n"
"RegNextDescPtr = 0x%08x\n"
"RegSWDescPtr = 0x%08x\n"
"RegCompletedDescPtr = 0x%08x\n"
"desc_pool_first = %p\n"
"desc_pool_last = %p\n"
"desc_next = %p\n"
"desc_completed = %p\n",
readl(ldev->eng_regs + 1),
readl(ldev->eng_regs + 2),
readl(ldev->eng_regs + 3),
readl(ldev->eng_regs + 4),
ldev->desc_pool_first,
ldev->desc_pool_last,
ldev->desc_next,
ldev->desc_completed
);
}
static DEVICE_ATTR(engine_regs, 0444, show_engine_regs, NULL);
static const struct attribute *ndd_attr_list[] = {
&dev_attr_engine_regs.attr,
NULL,
};
static struct class *kpc_dma_class;
/********** Platform Driver Functions **********/
static
int kpc_dma_probe(struct platform_device *pldev)
{
struct resource *r = NULL;
int rv = 0;
dev_t dev;
struct kpc_dma_device *ldev = kzalloc(sizeof(*ldev), GFP_KERNEL);
if (!ldev) {
dev_err(&pldev->dev, "%s: unable to kzalloc space for kpc_dma_device\n", __func__);
rv = -ENOMEM;
goto err_rv;
}
INIT_LIST_HEAD(&ldev->list);
ldev->pldev = pldev;
platform_set_drvdata(pldev, ldev);
atomic_set(&ldev->open_count, 1);
mutex_init(&ldev->sem);
lock_engine(ldev);
// Get Engine regs resource
r = platform_get_resource(pldev, IORESOURCE_MEM, 0);
if (!r) {
dev_err(&ldev->pldev->dev, "%s: didn't get the engine regs resource!\n", __func__);
rv = -ENXIO;
goto err_kfree;
}
ldev->eng_regs = ioremap(r->start, resource_size(r));
if (!ldev->eng_regs) {
dev_err(&ldev->pldev->dev, "%s: failed to ioremap engine regs!\n", __func__);
rv = -ENXIO;
goto err_kfree;
}
r = platform_get_resource(pldev, IORESOURCE_IRQ, 0);
if (!r) {
dev_err(&ldev->pldev->dev, "%s: didn't get the IRQ resource!\n", __func__);
rv = -ENXIO;
goto err_kfree;
}
ldev->irq = r->start;
// Setup miscdev struct
dev = MKDEV(assigned_major_num, pldev->id);
ldev->kpc_dma_dev = device_create(kpc_dma_class, &pldev->dev, dev, ldev, "kpc_dma%d", pldev->id);
if (IS_ERR(ldev->kpc_dma_dev)) {
dev_err(&ldev->pldev->dev, "%s: device_create failed: %d\n", __func__, rv);
goto err_kfree;
}
// Setup the DMA engine
rv = setup_dma_engine(ldev, 30);
if (rv) {
dev_err(&ldev->pldev->dev, "%s: failed to setup_dma_engine: %d\n", __func__, rv);
goto err_misc_dereg;
}
// Setup the sysfs files
rv = sysfs_create_files(&(ldev->pldev->dev.kobj), ndd_attr_list);
if (rv) {
dev_err(&ldev->pldev->dev, "%s: Failed to add sysfs files: %d\n", __func__, rv);
goto err_destroy_eng;
}
kpc_dma_add_device(ldev);
return 0;
err_destroy_eng:
destroy_dma_engine(ldev);
err_misc_dereg:
device_destroy(kpc_dma_class, dev);
err_kfree:
kfree(ldev);
err_rv:
return rv;
}
static
int kpc_dma_remove(struct platform_device *pldev)
{
struct kpc_dma_device *ldev = platform_get_drvdata(pldev);
if (!ldev)
return -ENXIO;
lock_engine(ldev);
sysfs_remove_files(&(ldev->pldev->dev.kobj), ndd_attr_list);
destroy_dma_engine(ldev);
kpc_dma_del_device(ldev);
device_destroy(kpc_dma_class, MKDEV(assigned_major_num, ldev->pldev->id));
kfree(ldev);
return 0;
}
/********** Driver Functions **********/
static struct platform_driver kpc_dma_plat_driver_i = {
.probe = kpc_dma_probe,
.remove = kpc_dma_remove,
.driver = {
.name = KP_DRIVER_NAME_DMA_CONTROLLER,
},
};
static
int __init kpc_dma_driver_init(void)
{
int err;
err = __register_chrdev(KPC_DMA_CHAR_MAJOR, 0, KPC_DMA_NUM_MINORS, "kpc_dma", &kpc_dma_fops);
if (err < 0) {
pr_err("Can't allocate a major number (%d) for kpc_dma (err = %d)\n", KPC_DMA_CHAR_MAJOR, err);
goto fail_chrdev_register;
}
assigned_major_num = err;
kpc_dma_class = class_create(THIS_MODULE, "kpc_dma");
err = PTR_ERR(kpc_dma_class);
if (IS_ERR(kpc_dma_class)) {
pr_err("Can't create class kpc_dma (err = %d)\n", err);
goto fail_class_create;
}
err = platform_driver_register(&kpc_dma_plat_driver_i);
if (err) {
pr_err("Can't register platform driver for kpc_dma (err = %d)\n", err);
goto fail_platdriver_register;
}
return err;
fail_platdriver_register:
class_destroy(kpc_dma_class);
fail_class_create:
__unregister_chrdev(KPC_DMA_CHAR_MAJOR, 0, KPC_DMA_NUM_MINORS, "kpc_dma");
fail_chrdev_register:
return err;
}
module_init(kpc_dma_driver_init);
static
void __exit kpc_dma_driver_exit(void)
{
platform_driver_unregister(&kpc_dma_plat_driver_i);
class_destroy(kpc_dma_class);
__unregister_chrdev(KPC_DMA_CHAR_MAJOR, 0, KPC_DMA_NUM_MINORS, "kpc_dma");
}
module_exit(kpc_dma_driver_exit);
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