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path: root/drivers/watchdog/renesas_wdt.c
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2017-09-09watchdog: renesas_wdt: update copyright datesWolfram Sang
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2017-09-09watchdog: renesas_wdt: make 'clk' a variable local to probe()Wolfram Sang
It is not needed outside probe() anymore. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2017-09-09watchdog: renesas_wdt: consistently use RuntimePM for clock managementWolfram Sang
On Renesas R-Car archs, RuntimePM does all the clock handling. So, use it consistently to enable/disable the clocks. Also make sure that clocks are really enabled around clk_get_rate(). clk_summary looks proper now: clock enable_cnt prepare_cnt rate ... Before this commit: At boot: rwdt 1 1 32768 0 0 WDT running: rwdt 2 2 32768 0 0 After this commit: At boot: rwdt 0 1 32768 0 0 WDT running rwdt 1 1 32768 0 0 Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2017-09-09watchdog: renesas_wdt: add another divider optionWolfram Sang
If we set RWTCSRB to 0, we can gain 4096 as another divider value. This is supported by all R-Car Gen2 and Gen3 devices which we aim to support. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2017-09-09watchdog: renesas_wdt: apply better precisionWolfram Sang
The error margin of the clks_per_second variable was too large and caused offsets when used with clock frequencies which left a remainder after applying the dividers. Now we always calculate directly using the clock rate and the divider using some helper macros. That also means that DIV_ROUND_UP moves from probe to the multiplication macro. In probe, we don't need to ensure anymore that 'clks_per_sec' would go too fast but rather ensure that the lower limit is really at least 1 to certainly get a full cycle. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2017-09-09watchdog: renesas_wdt: don't round closest with get_timeleftWolfram Sang
We should never return more time left than there actually is. So, switch to a plain divider instead of DIV_ROUND_CLOSEST. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2017-09-09watchdog: renesas_wdt: check rate also for upper limitWolfram Sang
When checking the clock rate, ensure also that counting all 16 bits takes at least one second to match the granularity of the framework. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2017-09-09watchdog: renesas_wdt: avoid (theoretical) type overflowWolfram Sang
Because the smallest clock divider we can select is 1, 'clks_per_sec' must be the same type as 'rate'. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2016-05-14watchdog: renesas-wdt: add driverWolfram Sang
Add support for watchdogs (RWDT and SWDT) found on RCar Gen3 based SoCs from Renesas. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>