path: root/drivers/gpu/host1x
diff options
authorSean Paul <seanpaul@chromium.org>2014-09-10 10:52:03 -0400
committerThierry Reding <treding@nvidia.com>2014-11-13 16:11:51 +0100
commit26f7a92a3a275cad7b0f39063e8cd92e002aff1a (patch)
tree5af76373db2acb8b581419e100dcedbbd75f9688 /drivers/gpu/host1x
parent57b17ae71f412b870415b698655f00846e34ce0a (diff)
gpu: host1x: mipi: Preserve the contents of MIPI_CAL_CTRL
By paving the CTRL reg value, the current code changes MIPI_CAL_PRESCALE ("Auto-cal calibration step prescale") from 1us to 0.1us (val=0). In the description for PHY's noise filter (MIPI_CAL_NOISE_FLT), the TRM states that if the value of the prescale is 0 (or 0.1us), the filter should be set between 2-5. However, the current code sets it to 0. For now, let's keep the prescale and filter values as-is, which is most likely the power-on-reset values of 0x2 and 0xa, respectively. Signed-off-by: Sean Paul <seanpaul@chromium.org> Signed-off-by: Thierry Reding <treding@nvidia.com>
Diffstat (limited to 'drivers/gpu/host1x')
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/gpu/host1x/mipi.c b/drivers/gpu/host1x/mipi.c
index a3e215a0116f..0d8c3ae8db6a 100644
--- a/drivers/gpu/host1x/mipi.c
+++ b/drivers/gpu/host1x/mipi.c
@@ -208,7 +208,9 @@ int tegra_mipi_calibrate(struct tegra_mipi_device *device)
tegra_mipi_writel(device->mipi, value, modules[i].reg);
- tegra_mipi_writel(device->mipi, MIPI_CAL_CTRL_START, MIPI_CAL_CTRL);
+ value = tegra_mipi_readl(device->mipi, MIPI_CAL_CTRL);
+ tegra_mipi_writel(device->mipi, value, MIPI_CAL_CTRL);
err = tegra_mipi_wait(device->mipi);