From 66d048ece86d238c0712a0a205479ce8842f3053 Mon Sep 17 00:00:00 2001
From: Marcin Chrzanowski <marcin.j.chrzanowski@gmail.com>
Date: Fri, 4 May 2018 21:06:13 +0200
Subject: Perform basic PCI initialization

---
 char.c | 20 ++++----------------
 char.h |  4 +++-
 pci.c  | 38 +++++++++++++++++++++++++++++++++++++-
 pci.h  |  1 +
 4 files changed, 45 insertions(+), 18 deletions(-)

diff --git a/char.c b/char.c
index c752713..db8ffcc 100644
--- a/char.c
+++ b/char.c
@@ -44,11 +44,7 @@ int new_doomdev(struct pci_dev *dev)
 		return -ENOMEM;
 	}
 
-	doom_data = kmalloc(sizeof(*doom_data), GFP_KERNEL);
-	if (doom_data == NULL) {
-		err = -ENOMEM;
-		goto error_kmalloc;
-	}
+	doom_data = pci_get_drvdata(dev);
 
 	doom_data->cdev = cdev_alloc();
 	if (doom_data->cdev == NULL) {
@@ -63,8 +59,6 @@ int new_doomdev(struct pci_dev *dev)
 	doom_data->device = device_create(doom_class, &dev->dev, devt, NULL,
 				"doom%d", minor),
 	ORFAIL_PTR(doom_data->device, error_create);
-	
-	pci_set_drvdata(dev, doom_data);
 
 	return 0;
 
@@ -72,19 +66,13 @@ error_create:
 	cdev_del(doom_data->cdev);
 error_add:
 error_cdev:
-	kfree(doom_data);
-error_kmalloc:
 	return err;
 }
 
-void destroy_doomdev(struct pci_dev *dev)
+void destroy_doomdev(struct doom_data *doom_data)
 {
-	struct doom_data *data;
-
-	data = pci_get_drvdata(dev);
-	device_destroy(doom_class, data->device->devt);
-	cdev_del(data->cdev);
-	kfree(data);
+	device_destroy(doom_class, doom_data->device->devt);
+	cdev_del(doom_data->cdev);
 }
 
 int char_init(void)
diff --git a/char.h b/char.h
index 31e82a2..a708023 100644
--- a/char.h
+++ b/char.h
@@ -3,8 +3,10 @@
 
 #include <linux/pci.h>
 
+#include "pci.h"
+
 int new_doomdev(struct pci_dev *dev);
-void destroy_doomdev(struct pci_dev *dev);
+void destroy_doomdev(struct doom_data *doom_data);
 int char_init(void);
 void char_cleanup(void);
 
diff --git a/pci.c b/pci.c
index ef6d5bf..95aad2e 100644
--- a/pci.c
+++ b/pci.c
@@ -10,16 +10,52 @@
 
 int doom_probe(struct pci_dev *dev, const struct pci_device_id *id)
 {
+	struct doom_data *doom_data;
 	int err = 0;
+
+	ORFAIL(pci_enable_device(dev), error_enable);
+	ORFAIL(pci_request_regions(dev, "harddoom"), error_regions);
+
+	doom_data = kmalloc(sizeof(*doom_data), GFP_KERNEL);
+	if (doom_data == NULL) {
+		err = -ENOMEM;
+		goto error_kmalloc;
+	}
+	pci_set_drvdata(dev, doom_data);
+	doom_data->iomem = pci_iomap(dev, 0, 0);
+
+	pci_set_master(dev);
+	pci_set_dma_mask(dev, DMA_BIT_MASK(32));
+	pci_set_consistent_dma_mask(dev, DMA_BIT_MASK(32));
+
 	ORFAIL(new_doomdev(dev), error_doomdev);
 
+	return 0;
+
 error_doomdev:
+	pci_clear_master(dev);
+	pci_iounmap(dev, doom_data->iomem);
+	kfree(doom_data);
+error_kmalloc:
+	pci_release_regions(dev);
+error_regions:
+	pci_disable_device(dev);
+error_enable:
 	return err;
 }
 
 void doom_remove (struct pci_dev *dev)
 {
-	destroy_doomdev(dev);
+	struct doom_data *doom_data;
+
+	doom_data = pci_get_drvdata(dev);
+
+	destroy_doomdev(doom_data);
+	pci_clear_master(dev);
+	pci_iounmap(dev, doom_data->iomem);
+	kfree(doom_data);
+	pci_release_regions(dev);
+	pci_disable_device(dev);
 }
 
 int doom_suspend (struct pci_dev *dev, pm_message_t state)
diff --git a/pci.h b/pci.h
index 9e8d07f..9386703 100644
--- a/pci.h
+++ b/pci.h
@@ -6,6 +6,7 @@
 struct doom_data {
 	struct cdev *cdev;
 	struct device *device;
+	void __iomem *iomem;
 };
 
 int pci_init(void);
-- 
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