Messages in this thread | | | Subject | Re: [RFC PATCH v5 12/14] gpu: host1x: mipi: Keep MIPI clock enabled till calibration is done | From | Sowjanya Komatineni <> | Date | Tue, 28 Jul 2020 09:04:32 -0700 |
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On 7/28/20 4:03 AM, Dmitry Osipenko wrote: > 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@nvidia.com> >> --- >> 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? No need to reset MIPI CAL > >> + 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.
CLKEN_OVR was always kept enabled in the driver prior to my patch and I was not touching that.
But as we are turning ON/OFF MIPI clock itself no need to unset CLKEN_OVR
> >> 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 >>
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