diff options
| author | Steven Rostedt <srostedt@redhat.com> | 2012-08-13 11:28:17 -0400 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2012-08-13 11:28:17 -0400 |
| commit | 139803a137dea5e02334692c20f07f19c42afc2e (patch) | |
| tree | 8c6a149f003aa3c366e44e9bfffb8b3cd6a01fc5 /drivers/rtc/rtc-wm831x.c | |
| parent | 69ebd1210e5fc6535320c9da4c6196b95fa0668c (diff) | |
| parent | 8524c7870680e93cb3d8f1d3f90f927c3c0686b6 (diff) | |
Merge tag 'v3.2.27' into v3.2-rt
This is the 3.2.27 stable release
Conflicts:
kernel/irq/handle.c
Diffstat (limited to 'drivers/rtc/rtc-wm831x.c')
| -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 bdc909bd56da..f3c211099a14 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 */ @@ -449,6 +469,8 @@ static int wm831x_rtc_probe(struct platform_device *pdev) alm_irq, ret); } + wm831x_rtc_add_randomness(wm831x); + return 0; err: |