Messages in this thread | | | Subject | Re: [RFC PATCH v3 16/18] gpu: host1x: mipi: Split tegra_mipi_calibrate and tegra_mipi_wait | From | Dmitry Osipenko <> | Date | Fri, 17 Jul 2020 00:18:39 +0300 |
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17.07.2020 00:09, Sowjanya Komatineni пишет: > > On 7/16/20 1:38 PM, Dmitry Osipenko wrote: >> 15.07.2020 07:20, Sowjanya Komatineni пишет: >>> SW can trigger MIPI pads calibration any time after power on >>> but calibration results will be latched and applied to the pads >>> by MIPI CAL unit only when the link is in LP-11 state and then >>> status register will be updated. >>> >>> For CSI, trigger of pads calibration happen during CSI stream >>> enable where CSI receiver is kept ready prior to sensor or CSI >>> transmitter stream start. >>> >>> So, pads may not be in LP-11 at this time and waiting for the >>> calibration to be done immediate after calibration start will >>> result in timeout. >>> >>> This patch splits tegra_mipi_calibrate() and tegra_mipi_wait() >>> so triggering for calibration and waiting for it to complete can >>> happen at different stages. >>> >>> Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com> >>> --- >> ... >>> int tegra_mipi_calibrate(struct tegra_mipi_device *device) >>> { >>> @@ -370,12 +381,10 @@ int tegra_mipi_calibrate(struct >>> tegra_mipi_device *device) >>> value |= MIPI_CAL_CTRL_START; >>> tegra_mipi_writel(device->mipi, value, MIPI_CAL_CTRL); >>> - err = tegra_mipi_wait(device->mipi); >> Doesn't MIPI clock need to be enabled during of the calibration process? > MIPI clock is already enabled in tegra_mipi_calibrate >> >>> mutex_unlock(&device->mipi->lock); >>> clk_disable(device->mipi->clk);
What keeps MIPI clock enabled after completion of the tegra_mipi_calibrate() invocation?
>>> - return err; >>> + return 0; >>> } >>> EXPORT_SYMBOL(tegra_mipi_calibrate);
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