From 26f7a92a3a275cad7b0f39063e8cd92e002aff1a Mon Sep 17 00:00:00 2001 From: Sean Paul Date: Wed, 10 Sep 2014 10:52:03 -0400 Subject: [PATCH] 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 Signed-off-by: Thierry Reding --- drivers/gpu/host1x/mipi.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) 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); + value |= MIPI_CAL_CTRL_START; + tegra_mipi_writel(device->mipi, value, MIPI_CAL_CTRL); err = tegra_mipi_wait(device->mipi); -- 2.30.2