27.07.2020 23:57, Sowjanya Komatineni пишет:
> With the split of MIPI calibration into tegra_mipi_calibrate() and
> tegra_mipi_wait(), MIPI clock is not kept enabled till the calibration
> is done.
>
> So, this patch skips disabling MIPI clock after triggering start of
> calibration and disables it only after waiting for done status from
> the calibration logic.
>
> This patch renames tegra_mipi_calibrate() as tegra_mipi_start_calibration()
> and tegra_mipi_wait() as tegra_mipi_finish_calibration() to be inline
> with their usage.
>
> As MIPI clock is left enabled and in case of any failures with CSI input
> streaming tegra_mipi_finish_calibration() will not get invoked.
> So added new API tegra_mipi_cancel_calibration() which disables MIPI clock
> and consumer drivers can call this in such cases.
>
> Signed-off-by: Sowjanya Komatineni <skomatineni@xxxxxxxxxx>
> ---
> drivers/gpu/drm/tegra/dsi.c | 4 ++--
> drivers/gpu/host1x/mipi.c | 19 ++++++++++---------
> include/linux/host1x.h | 5 +++--
> 3 files changed, 15 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/gpu/drm/tegra/dsi.c b/drivers/gpu/drm/tegra/dsi.c
> index 3820e8d..a7864e9 100644
> --- a/drivers/gpu/drm/tegra/dsi.c
> +++ b/drivers/gpu/drm/tegra/dsi.c
> @@ -694,11 +694,11 @@ static int tegra_dsi_pad_calibrate(struct tegra_dsi *dsi)
> DSI_PAD_PREEMP_PD(0x03) | DSI_PAD_PREEMP_PU(0x3);
> tegra_dsi_writel(dsi, value, DSI_PAD_CONTROL_3);
>
> - err = tegra_mipi_calibrate(dsi->mipi);
> + err = tegra_mipi_start_calibration(dsi->mipi);
> if (err < 0)
> return err;
>
> - return tegra_mipi_wait(dsi->mipi);
> + return tegra_mipi_finish_calibration(dsi->mipi);
> }
>
> static void tegra_dsi_set_timeout(struct tegra_dsi *dsi, unsigned long bclk,
> diff --git a/drivers/gpu/host1x/mipi.c b/drivers/gpu/host1x/mipi.c
> index e606464..b15ab6e 100644
> --- a/drivers/gpu/host1x/mipi.c
> +++ b/drivers/gpu/host1x/mipi.c
> @@ -293,17 +293,19 @@ int tegra_mipi_disable(struct tegra_mipi_device *dev)
> }
> EXPORT_SYMBOL(tegra_mipi_disable);
>
> -int tegra_mipi_wait(struct tegra_mipi_device *device)
> +void tegra_mipi_cancel_calibration(struct tegra_mipi_device *device)
> +{
Doesn't MIPI_CAL need to be reset here?
> + clk_disable(device->mipi->clk);
> +}
> +EXPORT_SYMBOL(tegra_mipi_cancel_calibration);
> +
> +int tegra_mipi_finish_calibration(struct tegra_mipi_device *device)
> {
> struct tegra_mipi *mipi = device->mipi;
> void __iomem *status_reg = mipi->regs + (MIPI_CAL_STATUS << 2);
> u32 value;
> int err;
>
> - err = clk_enable(device->mipi->clk);
> - if (err < 0)
> - return err;
> -
> mutex_lock(&device->mipi->lock);
>
> err = readl_relaxed_poll_timeout(status_reg, value,
> @@ -315,9 +317,9 @@ int tegra_mipi_wait(struct tegra_mipi_device *device)
>
> return err;
> }
> -EXPORT_SYMBOL(tegra_mipi_wait);
> +EXPORT_SYMBOL(tegra_mipi_finish_calibration);
>
> -int tegra_mipi_calibrate(struct tegra_mipi_device *device)
> +int tegra_mipi_start_calibration(struct tegra_mipi_device *device)
> {
> const struct tegra_mipi_soc *soc = device->mipi->soc;
> unsigned int i;
> @@ -382,11 +384,10 @@ int tegra_mipi_calibrate(struct tegra_mipi_device *device)
> tegra_mipi_writel(device->mipi, value, MIPI_CAL_CTRL);
This function sets MIPI_CAL_CLKEN_OVR bit, does it mean that MIPI clock
becomes always-ON?
I don't see where MIPI_CAL_CLKEN_OVR is unset.
> mutex_unlock(&device->mipi->lock);
> - clk_disable(device->mipi->clk);
>
> return 0;
> }
> -EXPORT_SYMBOL(tegra_mipi_calibrate);
> +EXPORT_SYMBOL(tegra_mipi_start_calibration);
>
> static const struct tegra_mipi_pad tegra114_mipi_pads[] = {
> { .data = MIPI_CAL_CONFIG_CSIA },
> diff --git a/include/linux/host1x.h b/include/linux/host1x.h
> index 20c885d..b490dda 100644
> --- a/include/linux/host1x.h
> +++ b/include/linux/host1x.h
> @@ -333,7 +333,8 @@ struct tegra_mipi_device *tegra_mipi_request(struct device *device,
> void tegra_mipi_free(struct tegra_mipi_device *device);
> int tegra_mipi_enable(struct tegra_mipi_device *device);
> int tegra_mipi_disable(struct tegra_mipi_device *device);
> -int tegra_mipi_calibrate(struct tegra_mipi_device *device);
> -int tegra_mipi_wait(struct tegra_mipi_device *device);
> +int tegra_mipi_start_calibration(struct tegra_mipi_device *device);
> +int tegra_mipi_finish_calibration(struct tegra_mipi_device *device);
> +void tegra_mipi_cancel_calibration(struct tegra_mipi_device *device);
>
> #endif
>
