kernel/linux.git/drivers/rtc/rtc-s3c.c, branch v4.14.217

rtc: s3c-rtc: Avoid using broken ALMYEAR register

2019-12-17T19:37:45+00:00

[ Upstream commit 50c8aec4212a966817e868056efc9bfbb73337c0 ] (RTC,ALM)YEAR registers of Exynos built-in RTC device contains 3 BCD characters. s3c-rtc driver uses only 2 lower of them and supports years from 2000..2099 range. The third BCD value is typically set to 0, but it looks that handling of it is broken in the hardware. It sometimes defaults to a random (even non-BCD) value. This is not an issue for handling RTCYEAR register, because bcd2bin() properly handles only 8bit values (2 BCD characters, the third one is skipped). The problem is however with ALMYEAR register and proper RTC alarm operation. When YEAREN bit is set for the configured alarm, RTC hardware triggers alarm only when ALMYEAR and RTCYEAR matches. This usually doesn't happen because of the random noise on the third BCD character. Fix this by simply skipping setting ALMYEAR register in alarm configuration. This workaround fixes broken alarm operation on Exynos built-in rtc device. My tests revealed that the issue happens on the following Exynos series: 3250, 4210, 4412, 5250 and 5410. Signed-off-by: Marek Szyprowski Signed-off-by: Alexandre Belloni Signed-off-by: Sasha Levin

rtc: s3c: Handle clock enable failures

2017-06-24T20:52:43+00:00

clk_enable() can fail so handle such case. Signed-off-by: Krzysztof Kozlowski Signed-off-by: Alexandre Belloni

rtc: s3c: Handle clock prepare failures in probe

2017-06-24T20:52:40+00:00

clk_prepare_enable() can fail so handle such case. Signed-off-by: Krzysztof Kozlowski Signed-off-by: Alexandre Belloni

rtc: s3c: Do not remove const from rodata memory

2017-06-24T20:52:38+00:00

All instances of struct s3c_rtc_data are in fact static const thus put in rodata so we should not drop the const while getting the pointer to them. Signed-off-by: Krzysztof Kozlowski Signed-off-by: Alexandre Belloni

rtc: s3c: Drop unneeded cast to void pointer

2017-06-24T20:52:35+00:00

There is no need for casting to void pointer for of_device_id data. Signed-off-by: Krzysztof Kozlowski Signed-off-by: Alexandre Belloni

rtc: s3c: Minor white-space cleanups

2017-06-24T20:52:34+00:00

Minor cleanups to make the code easier to read. No functional changes. 1. Remove one space before labels as this is nowadays mostly preferred. 2. Fix indentation of arguments in function calls. 3. Split structure member declaration. Signed-off-by: Krzysztof Kozlowski Signed-off-by: Alexandre Belloni

rtc: s3c: Jump to central exit point on getting src clock error

2017-06-24T20:52:32+00:00

In other error paths in probe, centralized exit point was used so make this consistent. Signed-off-by: Krzysztof Kozlowski Signed-off-by: Alexandre Belloni

rtc: s3c: Add s3c_rtc_{enable/disable}_clk in s3c_rtc_setfreq()

2016-07-19T15:48:06+00:00

As per code flow s3c_rtc_setfreq() will get called with rtc clock disabled and in set_freq we perform h/w registers read/write, which results in a kernel crash on exynos7 platform while probing rtc driver. Below is code flow: s3c_rtc_probe() clk_prepare_enable(info->rtc_clk) // rtc clock enabled s3c_rtc_gettime() // will enable clk if not done, and disable it upon exit s3c_rtc_setfreq() //then this will be called with clk disabled This patch take cares of such issue by adding s3c_rtc_{enable/disable}_clk in s3c_rtc_setfreq(). Fixes: 24e1455493da ("drivers/rtc/rtc-s3c.c: delete duplicate clock control") Cc: Signed-off-by: Alim Akhtar Reviewed-by: Krzysztof Kozlowski Reviewed-by: Pankaj Dubey Tested-by: Pankaj Dubey Signed-off-by: Alexandre Belloni

rtc: s3c: Remove unnecessary call to disable already disabled clock

2016-07-19T15:48:04+00:00

At the end of s3c_rtc_probe(), s3c_rtc_disable_clk() being called with rtc clock already disabled (by s3c_rtc_gettime()), which looks extra and unnecessary call. Lets clean it up. Signed-off-by: Alim Akhtar Reviewed-by: Krzysztof Kozlowski Reviewed-by: Pankaj Dubey Tested-by: Pankaj Dubey Signed-off-by: Alexandre Belloni

rtc: simplify implementations of read_alarm

2016-07-09T08:24:45+00:00

Since commit d68778b80dd7 ("rtc: initialize output parameter for read alarm to "uninitialized"") there is no need to explicitly set unsupported members to -1. So drop the respective assignments from drivers. Signed-off-by: Uwe Kleine-König Signed-off-by: Alexandre Belloni