[PATCH v5 04/15] misc: bcm-vk: add misc device to Broadcom VK driver

[Scott Branden]

Add misc device base support to create and remove devnode.
Additional misc functions for open/read/write/release/ioctl/sysfs, etc
will be added in follow on commits to allow for individual review.

Co-developed-by: Desmond Yan <desmond....@broadcom.com>
Signed-off-by: Desmond Yan <desmond....@broadcom.com>
Signed-off-by: Scott Branden <scott.bran...@broadcom.com>
---
 drivers/misc/bcm-vk/bcm_vk.h     |  2 ++
 drivers/misc/bcm-vk/bcm_vk_dev.c | 36 +++++++++++++++++++++++++++++++-
 2 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/bcm-vk/bcm_vk.h b/drivers/misc/bcm-vk/bcm_vk.h
index c4fb61a84e41..0a366db693c8 100644
--- a/drivers/misc/bcm-vk/bcm_vk.h
+++ b/drivers/misc/bcm-vk/bcm_vk.h
@@ -7,6 +7,7 @@
 #define BCM_VK_H
 
 #include <linux/firmware.h>
+#include <linux/miscdevice.h>
 #include <linux/pci.h>
 #include <linux/sched/signal.h>
 
@@ -214,6 +215,7 @@ struct bcm_vk {
 
        struct bcm_vk_dauth_info dauth_info;
 
+       struct miscdevice miscdev;
        int devid; /* dev id allocated */
 
        struct workqueue_struct *wq_thread;
diff --git a/drivers/misc/bcm-vk/bcm_vk_dev.c b/drivers/misc/bcm-vk/bcm_vk_dev.c
index 50a65f6f290b..c46591124eb4 100644
--- a/drivers/misc/bcm-vk/bcm_vk_dev.c
+++ b/drivers/misc/bcm-vk/bcm_vk_dev.c
@@ -7,6 +7,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/firmware.h>
 #include <linux/fs.h>
+#include <linux/idr.h>
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/pci_regs.h>
@@ -638,6 +639,7 @@ static int bcm_vk_probe(struct pci_dev *pdev, const struct 
pci_device_id *ent)
        char name[20];
        struct bcm_vk *vk;
        struct device *dev = &pdev->dev;
+       struct miscdevice *misc_device;
        u32 boot_status;
 
        vk = kzalloc(sizeof(*vk), GFP_KERNEL);
@@ -713,6 +715,19 @@ static int bcm_vk_probe(struct pci_dev *pdev, const struct 
pci_device_id *ent)
 
        vk->devid = id;
        snprintf(name, sizeof(name), DRV_MODULE_NAME ".%d", id);
+       misc_device = &vk->miscdev;
+       misc_device->minor = MISC_DYNAMIC_MINOR;
+       misc_device->name = kstrdup(name, GFP_KERNEL);
+       if (!misc_device->name) {
+               err = -ENOMEM;
+               goto err_ida_remove;
+       }
+
+       err = misc_register(misc_device);
+       if (err) {
+               dev_err(dev, "failed to register device\n");
+               goto err_kfree_name;
+       }
 
        INIT_WORK(&vk->wq_work, bcm_vk_wq_handler);
 
@@ -721,7 +736,7 @@ static int bcm_vk_probe(struct pci_dev *pdev, const struct 
pci_device_id *ent)
        if (!vk->wq_thread) {
                dev_err(dev, "Fail to create workqueue thread\n");
                err = -ENOMEM;
-               goto err_ida_remove;
+               goto err_misc_deregister;
        }
 
        /* sync other info */
@@ -743,11 +758,20 @@ static int bcm_vk_probe(struct pci_dev *pdev, const 
struct pci_device_id *ent)
                }
        }
 
+       dev_dbg(dev, "BCM-VK:%u created, 0x%p\n", id, vk);
+
        return 0;
 
 err_destroy_workqueue:
        destroy_workqueue(vk->wq_thread);
 
+err_misc_deregister:
+       misc_deregister(misc_device);
+
+err_kfree_name:
+       kfree(misc_device->name);
+       misc_device->name = NULL;
+
 err_ida_remove:
        ida_simple_remove(&bcm_vk_ida, id);
 
@@ -777,6 +801,7 @@ static void bcm_vk_remove(struct pci_dev *pdev)
 {
        int i;
        struct bcm_vk *vk = pci_get_drvdata(pdev);
+       struct miscdevice *misc_device = &vk->miscdev;
 
        /*
         * Trigger a reset to card and wait enough time for UCODE to rerun,
@@ -791,6 +816,13 @@ static void bcm_vk_remove(struct pci_dev *pdev)
                dma_free_coherent(&pdev->dev, nr_scratch_pages * PAGE_SIZE,
                                  vk->tdma_vaddr, vk->tdma_addr);
 
+       /* remove if name is set which means misc dev registered */
+       if (misc_device->name) {
+               misc_deregister(misc_device);
+               kfree(misc_device->name);
+               ida_simple_remove(&bcm_vk_ida, vk->devid);
+       }
+
        cancel_work_sync(&vk->wq_work);
        destroy_workqueue(vk->wq_thread);
 
@@ -799,6 +831,8 @@ static void bcm_vk_remove(struct pci_dev *pdev)
                        pci_iounmap(pdev, vk->bar[i]);
        }
 
+       dev_dbg(&pdev->dev, "BCM-VK:%d released\n", vk->devid);
+
        pci_release_regions(pdev);
        pci_free_irq_vectors(pdev);
        pci_disable_device(pdev);
-- 
2.17.1