On 06/02/13 17:09, Russell King - ARM Linux wrote:
On Sun, Jun 02, 2013 at 04:58:49PM +0200, Oliver Schinagl wrote:
+#include <asm/io.h>
We have an include file called linux/io.h. Please use linux/*.h files which
include asm/*.h files in preference to directly using asm/*.h.
In fact, no driver should include an asm/*.h header.
And I didn't have that there, but it kept refusing to find ioread32be.
Of course, now I change it back to linux/io.h (which I had, I swear) and
all works swell.
Concider it changed.
+#include <linux/compiler.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/kobject.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/random.h>
+#include <linux/stat.h>
+#include <linux/sysfs.h>
+#include <linux/types.h>
+
+#define DRV_NAME "sunxi-sid"
+#define DRV_VERSION "1.0"
+
+/* There are 4 32-bit keys */
+#define SID_KEYS 4
+/* and 4 byte sized keys per 32-bit key */
+#define SID_SIZE (SID_KEYS * 4)
+
+static void __iomem *p_sid_reg_base;
+
+/* We read the entire key, but only return the requested byte. This is of
+ * course slower then it could be and uses 4 times more reads as needed but
+ * keeps code a simpler.
+ */
+u8 sunxi_sid_read_byte(const int offset)
+{
+ u32 sid_key;
+ u8 ret;
+
+ ret = 0;
+
+ if (likely((SID_SIZE))) {
+ sid_key = ioread32be(p_sid_reg_base + round_down(offset, 4));
+ sid_key >>= (offset % 4) * 8;
+ ret = sid_key & 0xff;
+ }
What happens if you unbind the device in sysfs and then try and use
this function?
+static int sunxi_sid_remove(struct platform_device *pdev)
+{
+ device_remove_bin_file(&pdev->dev, &sid_bin_attr);
+ dev_info(&pdev->dev, "Sunxi SID driver unloaded successfully.\n");
Maybe you want to set p_sid_reg_base to NULL here?
+
+ return 0;
+}
+
+static int __init sunxi_sid_probe(struct platform_device *pdev)
+{
+ int entropy[SID_SIZE], i, ret;
+ struct device *dev;
+ struct resource *res;
+ void __iomem *sid_reg_base;
+
+ dev = &pdev->dev;
+ if (unlikely(!pdev->dev.of_node)) {
+ dev_err(dev, "No devicetree data available\n");
+ ret = -EFAULT;
+ goto exit;
+ }
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ sid_reg_base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(sid_reg_base)) {
+ dev_err(dev, "Unable to obtain resource\n");
+ ret = PTR_ERR(sid_reg_base);
+ goto exit;
+ }
+ platform_set_drvdata(pdev, sid_reg_base);
+ p_sid_reg_base = sid_reg_base;
So what happens if you have two of these devices? Maybe you want to check
whether p_sid_reg_base is already set?
+
+ ret = device_create_bin_file(dev, &sid_bin_attr);
+ if (unlikely(ret)) {
+ dev_err(dev, "Unable to create sysfs bin entry\n");
+ goto exit;
+ }
+
+ for (i = 0; i < SID_SIZE; i++)
+ entropy[i] = sunxi_sid_read_byte(i);
+ add_device_randomness(entropy, SID_SIZE);
+
+ dev_info(dev, "Sunxi SID driver loaded successfully.\n");
Do we really need to report that the driver "loaded successfully" ?
Do we need lots of lines in the kernel log telling us simply that
random driver X was built into the kernel or the module was loaded?
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