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2018-07-09hw/timer/cmsdk-apb-timer: run or stop timer on writes to RELOAD and VALUEPeter Maydell
If the CMSDK APB timer is set up with a zero RELOAD value then it will count down to zero, fire once and then stay at zero. From the point of view of the ptimer system, the timer is disabled; but the enable bit in the CTRL register is still set and if the guest subsequently writes to the RELOAD or VALUE registers this should cause the timer to start counting down again. Add code to the write paths for RELOAD and VALUE so that we correctly restart the timer in this situation. Conversely, if the new RELOAD and VALUE are both zero, we should stop the ptimer. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Tested-by: Guenter Roeck <linux@roeck-us.net> Message-id: 20180703171044.9503-5-peter.maydell@linaro.org
2018-07-09hw/timer/cmsdk-apb-timer: Correctly identify and set one-shot modeGuenter Roeck
The CMSDK APB timer is currently always configured as periodic timer. This results in the following messages when trying to boot Linux. Timer with delta zero, disabling If the timer limit set with the RELOAD command is 0, the timer needs to be enabled as one-shot timer. Signed-off-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2018-07-09hw/timer/cmsdk-apb-timer: Correct ptimer policy settingsPeter Maydell
The CMSDK timer interrupt triggers when the counter goes from 1 to 0, so we want to trigger immediately, rather than waiting for a clock cycle. Drop the incorrect NO_IMMEDIATE_TRIGGER setting. We also do not want to get an interrupt if the guest sets the counter directly to zero, so use the new TRIGGER_ONLY_ON_DECREMENT policy. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Tested-by: Guenter Roeck <linux@roeck-us.net> Message-id: 20180703171044.9503-3-peter.maydell@linaro.org
2017-07-17hw/char/cmsdk-apb-timer: Implement CMSDK APB timer devicePeter Maydell
Implement a model of the simple timer device found in the CMSDK. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-id: 1500029487-14822-5-git-send-email-peter.maydell@linaro.org