drm/stm: dsi: check hardware version

Check version of DSI hardware IP. Only versions 1.30 & 1.31
are supported.

Signed-off-by: Yannick Fertré <yannick.fertre@st.com>
Acked-by: Philippe Cornu <philippe.cornu@st.com>
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1557500579-19720-1-git-send-email-yannick.fertre@st.com

diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
index d8e4a14..01db020 100644 (file)
--- a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
+++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
@@ -227,7 +227,6 @@ dw_mipi_dsi_get_lane_mbps(void *priv_data, const struct drm_display_mode *mode,
        u32 val;
 
        /* Update lane capabilities according to hw version */
-       dsi->hw_version = dsi_read(dsi, DSI_VERSION) & VERSION;
        dsi->lane_min_kbps = LANE_MIN_KBPS;
        dsi->lane_max_kbps = LANE_MAX_KBPS;
        if (dsi->hw_version == HWVER_131) {
@@ -306,6 +305,7 @@ static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
 {
        struct device *dev = &pdev->dev;
        struct dw_mipi_dsi_stm *dsi;
+       struct clk *pclk;
        struct resource *res;
        int ret;
 
@@ -348,6 +348,28 @@ static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
                goto err_clk_get;
        }
 
+       pclk = devm_clk_get(dev, "pclk");
+       if (IS_ERR(pclk)) {
+               ret = PTR_ERR(pclk);
+               DRM_ERROR("Unable to get peripheral clock: %d\n", ret);
+               goto err_dsi_probe;
+       }
+
+       ret = clk_prepare_enable(pclk);
+       if (ret) {
+               DRM_ERROR("%s: Failed to enable peripheral clk\n", __func__);
+               goto err_dsi_probe;
+       }
+
+       dsi->hw_version = dsi_read(dsi, DSI_VERSION) & VERSION;
+       clk_disable_unprepare(pclk);
+
+       if (dsi->hw_version != HWVER_130 && dsi->hw_version != HWVER_131) {
+               ret = -ENODEV;
+               DRM_ERROR("bad dsi hardware version\n");
+               goto err_dsi_probe;
+       }
+
        dw_mipi_dsi_stm_plat_data.base = dsi->base;
        dw_mipi_dsi_stm_plat_data.priv_data = dsi;