diff options
| author | Varun Wadekar <vwadekar@nvidia.com> | 2012-08-23 15:07:36 +0530 |
|---|---|---|
| committer | Varun Wadekar <vwadekar@nvidia.com> | 2012-08-23 15:07:36 +0530 |
| commit | ce078e4f80e0d82730d42be0ee44b9e6e1dd3866 (patch) | |
| tree | 1c979b4d93de957a2cb7bb1e4a8068b62b02b663 /drivers/rtc | |
| parent | 929b4be511e72a31d4ca9447a12dcc672d544f25 (diff) | |
| parent | 196ad09b956e63131e3d196e490a4dfbb85e875f (diff) | |
Merge commit 'v3.4.9' into android-t114-3.4
Linux v3.4.9
Conflicts:
arch/arm/kernel/smp.c
arch/arm/vfp/entry.S
Change-Id: I731e815ed35ba9280374a5a3e5a6a8b6b805d695
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
Diffstat (limited to 'drivers/rtc')
| -rw-r--r-- | drivers/rtc/rtc-wm831x.c | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/drivers/rtc/rtc-wm831x.c b/drivers/rtc/rtc-wm831x.c index 3b6e6a67e765..41c06fe5415c 100644 --- a/drivers/rtc/rtc-wm831x.c +++ b/drivers/rtc/rtc-wm831x.c @@ -24,7 +24,7 @@ #include <linux/mfd/wm831x/core.h> #include <linux/delay.h> #include <linux/platform_device.h> - +#include <linux/random.h> /* * R16416 (0x4020) - RTC Write Counter @@ -96,6 +96,26 @@ struct wm831x_rtc { unsigned int alarm_enabled:1; }; +static void wm831x_rtc_add_randomness(struct wm831x *wm831x) +{ + int ret; + u16 reg; + + /* + * The write counter contains a pseudo-random number which is + * regenerated every time we set the RTC so it should be a + * useful per-system source of entropy. + */ + ret = wm831x_reg_read(wm831x, WM831X_RTC_WRITE_COUNTER); + if (ret >= 0) { + reg = ret; + add_device_randomness(®, sizeof(reg)); + } else { + dev_warn(wm831x->dev, "Failed to read RTC write counter: %d\n", + ret); + } +} + /* * Read current time and date in RTC */ @@ -431,6 +451,8 @@ static int wm831x_rtc_probe(struct platform_device *pdev) alm_irq, ret); } + wm831x_rtc_add_randomness(wm831x); + return 0; err: |