diff options
Diffstat (limited to 'drivers/rtc/rtc-wm831x.c')
| -rw-r--r-- | drivers/rtc/rtc-wm831x.c | 99 |
1 files changed, 31 insertions, 68 deletions
diff --git a/drivers/rtc/rtc-wm831x.c b/drivers/rtc/rtc-wm831x.c index 82931dc65c0..75aea4c4d33 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 */ @@ -315,21 +335,6 @@ static int wm831x_rtc_alarm_irq_enable(struct device *dev, return wm831x_rtc_stop_alarm(wm831x_rtc); } -static int wm831x_rtc_update_irq_enable(struct device *dev, - unsigned int enabled) -{ - struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev); - int val; - - if (enabled) - val = 1 << WM831X_RTC_PINT_FREQ_SHIFT; - else - val = 0; - - return wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL, - WM831X_RTC_PINT_FREQ_MASK, val); -} - static irqreturn_t wm831x_alm_irq(int irq, void *data) { struct wm831x_rtc *wm831x_rtc = data; @@ -339,22 +344,12 @@ static irqreturn_t wm831x_alm_irq(int irq, void *data) return IRQ_HANDLED; } -static irqreturn_t wm831x_per_irq(int irq, void *data) -{ - struct wm831x_rtc *wm831x_rtc = data; - - rtc_update_irq(wm831x_rtc->rtc, 1, RTC_IRQF | RTC_UF); - - return IRQ_HANDLED; -} - static const struct rtc_class_ops wm831x_rtc_ops = { .read_time = wm831x_rtc_readtime, .set_mmss = wm831x_rtc_set_mmss, .read_alarm = wm831x_rtc_readalarm, .set_alarm = wm831x_rtc_setalarm, .alarm_irq_enable = wm831x_rtc_alarm_irq_enable, - .update_irq_enable = wm831x_rtc_update_irq_enable, }; #ifdef CONFIG_PM @@ -421,11 +416,10 @@ static int wm831x_rtc_probe(struct platform_device *pdev) { struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent); struct wm831x_rtc *wm831x_rtc; - int per_irq = platform_get_irq_byname(pdev, "PER"); - int alm_irq = platform_get_irq_byname(pdev, "ALM"); + int alm_irq = wm831x_irq(wm831x, platform_get_irq_byname(pdev, "ALM")); int ret = 0; - wm831x_rtc = kzalloc(sizeof(*wm831x_rtc), GFP_KERNEL); + wm831x_rtc = devm_kzalloc(&pdev->dev, sizeof(*wm831x_rtc), GFP_KERNEL); if (wm831x_rtc == NULL) return -ENOMEM; @@ -442,50 +436,30 @@ static int wm831x_rtc_probe(struct platform_device *pdev) device_init_wakeup(&pdev->dev, 1); - wm831x_rtc->rtc = rtc_device_register("wm831x", &pdev->dev, + wm831x_rtc->rtc = devm_rtc_device_register(&pdev->dev, "wm831x", &wm831x_rtc_ops, THIS_MODULE); if (IS_ERR(wm831x_rtc->rtc)) { ret = PTR_ERR(wm831x_rtc->rtc); goto err; } - ret = request_threaded_irq(per_irq, NULL, wm831x_per_irq, - IRQF_TRIGGER_RISING, "RTC period", - wm831x_rtc); - if (ret != 0) { - dev_err(&pdev->dev, "Failed to request periodic IRQ %d: %d\n", - per_irq, ret); - } - - ret = request_threaded_irq(alm_irq, NULL, wm831x_alm_irq, - IRQF_TRIGGER_RISING, "RTC alarm", - wm831x_rtc); + ret = devm_request_threaded_irq(&pdev->dev, alm_irq, NULL, + wm831x_alm_irq, + IRQF_TRIGGER_RISING, "RTC alarm", + wm831x_rtc); if (ret != 0) { dev_err(&pdev->dev, "Failed to request alarm IRQ %d: %d\n", alm_irq, ret); } + wm831x_rtc_add_randomness(wm831x); + return 0; err: - kfree(wm831x_rtc); return ret; } -static int __devexit wm831x_rtc_remove(struct platform_device *pdev) -{ - struct wm831x_rtc *wm831x_rtc = platform_get_drvdata(pdev); - int per_irq = platform_get_irq_byname(pdev, "PER"); - int alm_irq = platform_get_irq_byname(pdev, "ALM"); - - free_irq(alm_irq, wm831x_rtc); - free_irq(per_irq, wm831x_rtc); - rtc_device_unregister(wm831x_rtc->rtc); - kfree(wm831x_rtc); - - return 0; -} - static const struct dev_pm_ops wm831x_rtc_pm_ops = { .suspend = wm831x_rtc_suspend, .resume = wm831x_rtc_resume, @@ -499,24 +473,13 @@ static const struct dev_pm_ops wm831x_rtc_pm_ops = { static struct platform_driver wm831x_rtc_driver = { .probe = wm831x_rtc_probe, - .remove = __devexit_p(wm831x_rtc_remove), .driver = { .name = "wm831x-rtc", .pm = &wm831x_rtc_pm_ops, }, }; -static int __init wm831x_rtc_init(void) -{ - return platform_driver_register(&wm831x_rtc_driver); -} -module_init(wm831x_rtc_init); - -static void __exit wm831x_rtc_exit(void) -{ - platform_driver_unregister(&wm831x_rtc_driver); -} -module_exit(wm831x_rtc_exit); +module_platform_driver(wm831x_rtc_driver); MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); MODULE_DESCRIPTION("RTC driver for the WM831x series PMICs"); |