[PATCH 5.4 033/320] drm/rockchip: dsi: Reconfigure hardware on resume()

Greg Kroah-Hartman
2022-01-24T20:00:58Z

From: Brian Norris <briannorris@chromium.org>

commit e584cdc1549932f87a2707b56bc588cfac5d89e0 upstream.

Since commit 43c2de1002d2 ("drm/rockchip: dsi: move all lane config except
LCDC mux to bind()"), we perform most HW configuration in the bind()
function. This configuration may be lost on suspend/resume, so we
need to call it again. That may lead to errors like this after system
suspend/resume:

dw-mipi-dsi-rockchip ff968000.mipi: failed to write command FIFO
panel-kingdisplay-kd097d04 ff960000.mipi.0: failed write init cmds: -110

Tested on Acer Chromebook Tab 10 (RK3399 Gru-Scarlet).

Note that early mailing list versions of this driver borrowed Rockchip's
downstream/BSP solution, to do HW configuration in mode_set() (which
*is* called at the appropriate pre-enable() times), but that was
discarded along the way. I've avoided that still, because mode_set()
documentation doesn't suggest this kind of purpose as far as I can tell.

Fixes: 43c2de1002d2 ("drm/rockchip: dsi: move all lane config except LCDC mux to bind()")
Cc: <stable@vger.kernel.org>
Signed-off-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210928143413.v3.2.I4e9d93aadb00b1ffc7d506e3186a25492bf0b732@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c | 37 ++++++++++++++++++++++++
1 file changed, 37 insertions(+)

--- a/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
+++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
@@ -231,6 +231,8 @@ struct dw_mipi_dsi_rockchip {
struct dw_mipi_dsi *dmd;
const struct rockchip_dw_dsi_chip_data *cdata;
struct dw_mipi_dsi_plat_data pdata;
+
+ bool dsi_bound;
};

struct dphy_pll_parameter_map {
@@ -821,6 +823,8 @@ static int dw_mipi_dsi_rockchip_bind(str
goto out_pm_runtime;
}

+ dsi->dsi_bound = true;
+
return 0;

out_pm_runtime:
@@ -840,6 +844,8 @@ static void dw_mipi_dsi_rockchip_unbind(
if (dsi->is_slave)
return;

+ dsi->dsi_bound = false;
+
dw_mipi_dsi_unbind(dsi->dmd);

clk_disable_unprepare(dsi->pllref_clk);
@@ -904,6 +910,36 @@ static const struct dw_mipi_dsi_host_ops
.detach = dw_mipi_dsi_rockchip_host_detach,
};

+static int __maybe_unused dw_mipi_dsi_rockchip_resume(struct device *dev)
+{
+ struct dw_mipi_dsi_rockchip *dsi = dev_get_drvdata(dev);
+ int ret;
+
+ /*
+ * Re-configure DSI state, if we were previously initialized. We need
+ * to do this before rockchip_drm_drv tries to re-enable() any panels.
+ */
+ if (dsi->dsi_bound) {
+ ret = clk_prepare_enable(dsi->grf_clk);
+ if (ret) {
+ DRM_DEV_ERROR(dsi->dev, "Failed to enable grf_clk: %d\n", ret);
+ return ret;
+ }
+
+ dw_mipi_dsi_rockchip_config(dsi);
+ if (dsi->slave)
+ dw_mipi_dsi_rockchip_config(dsi->slave);
+
+ clk_disable_unprepare(dsi->grf_clk);
+ }
+
+ return 0;
+}
+
+static const struct dev_pm_ops dw_mipi_dsi_rockchip_pm_ops = {
+ SET_LATE_SYSTEM_SLEEP_PM_OPS(NULL, dw_mipi_dsi_rockchip_resume)
+};
+
static int dw_mipi_dsi_rockchip_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
@@ -1089,6 +1125,7 @@ struct platform_driver dw_mipi_dsi_rockc
.remove = dw_mipi_dsi_rockchip_remove,
.driver = {
.of_match_table = dw_mipi_dsi_rockchip_dt_ids,
+ .pm = &dw_mipi_dsi_rockchip_pm_ops,
.name = "dw-mipi-dsi-rockchip",
},
};