Re: [PATCH v1 3/5] gpu/drm: host1x: mipi: add Tegra20/Tegra30 MIPI calibration logic

пт, 18 лип. 2025 р. о 12:11 Mikko Perttunen [off-list ref] пише:

On Thursday, July 17, 2025 11:21 PM Svyatoslav Ryhel wrote:

quoted

...

@@ -311,6 +330,43 @@ int tegra_mipi_finish_calibration(struct

tegra_mipi_device *device) }
 EXPORT_SYMBOL(tegra_mipi_finish_calibration);

+static int tegra20_mipi_calibration(struct tegra_mipi_device *device)
+{
+     struct tegra_mipi *mipi = device->mipi;
+     const struct tegra_mipi_soc *soc = mipi->soc;
+     u32 value;
+     int err;
+
+     err = clk_enable(mipi->csi_clk);
+     if (err < 0)
+             return err;
+
+     mutex_lock(&mipi->lock);
+
+     value = MIPI_CAL_CONFIG_TERMOS(soc->termos);
+     tegra_mipi_writel(mipi, value, CSI_CILA_MIPI_CAL_CONFIG);
+
+     value = MIPI_CAL_CONFIG_TERMOS(soc->termos);
+     tegra_mipi_writel(mipi, value, CSI_CILB_MIPI_CAL_CONFIG);
+
+     value = MIPI_CAL_CONFIG_HSPDOS(soc->hspdos) |
+             MIPI_CAL_CONFIG_HSPUOS(soc->hspuos);
+     tegra_mipi_writel(mipi, value, CSI_DSI_MIPI_CAL_CONFIG);
+
+     value = MIPI_CAL_BIAS_PAD_DRV_DN_REF(soc->pad_drive_down_ref) |
+             MIPI_CAL_BIAS_PAD_DRV_UP_REF(soc->pad_drive_up_ref);
+     tegra_mipi_writel(mipi, value, CSI_MIPIBIAS_PAD_CONFIG);
+
+     tegra_mipi_writel(mipi, 0x0, CSI_CIL_PAD_CONFIG);
+
+     mutex_unlock(&mipi->lock);
+
+     clk_disable(mipi->csi_clk);
+     clk_disable(mipi->clk);
+
+     return 0;
+}
+

Where does this sequence come from? It looks a bit strange to me, since it
doesn't trigger calibration at all. It would be useful to mention the source
in the commit message.

Mikko

Downstream nvidia sources, 3.1.10 and 3.4, dsi driver, function
tegra_dsi_pad_calibration