From: Marek Vasut <marex@xxxxxxx>
Implement support for DSI clock and data lane DN/DP polarity swap by
means of decoding 'lane-polarities' DT property. The controller does
support DN/DP swap of clock lane and all data lanes, the controller
does not support polarity swap of individual data lane bundles, add
a check which verifies all data lanes have the same polarity.
This has been validated on an imx8mm board that actually has the MIPI DSI
clock lanes inverted.
Signed-off-by: Marek Vasut <marex@xxxxxxx>
Signed-off-by: Fabio Estevam <festevam@xxxxxxx>
Reviewed-by: Jagan Teki <jagan@xxxxxxxxxxxxxxxxxxxx>
---
Changes since v1:
- Use 'drm: bridge: samsung-dsim:' as prefix (Jagan).
- Collected Jagan's Reviewed-by tag.
drivers/gpu/drm/bridge/samsung-dsim.c | 27 ++++++++++++++++++++++++++-
include/drm/bridge/samsung-dsim.h | 2 ++
2 files changed, 28 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c
index e0a402a85787..5791148e2da2 100644
--- a/drivers/gpu/drm/bridge/samsung-dsim.c
+++ b/drivers/gpu/drm/bridge/samsung-dsim.c
@@ -183,6 +183,8 @@
#define DSIM_AFC_CTL(x) (((x) & 0x7) << 5)
/* DSIM_PLLCTRL */
+#define DSIM_PLL_DPDNSWAP_CLK (1 << 25)
+#define DSIM_PLL_DPDNSWAP_DAT (1 << 24)
#define DSIM_FREQ_BAND(x) ((x) << 24)
#define DSIM_PLL_EN BIT(23)
#define DSIM_PLL_P(x, offset) ((x) << (offset))
@@ -622,6 +624,11 @@ static unsigned long samsung_dsim_set_pll(struct samsung_dsim *dsi,
reg |= DSIM_FREQ_BAND(band);
}
+ if (dsi->swap_dn_dp_clk)
+ reg |= DSIM_PLL_DPDNSWAP_CLK;
+ if (dsi->swap_dn_dp_data)
+ reg |= DSIM_PLL_DPDNSWAP_DAT;
+
samsung_dsim_write(dsi, DSIM_PLLCTRL_REG, reg);
timeout = 1000;
@@ -1696,7 +1703,9 @@ static int samsung_dsim_parse_dt(struct samsung_dsim *dsi)
{
struct device *dev = dsi->dev;
struct device_node *node = dev->of_node;
- int ret;
+ u32 lane_polarities[5] = { 0 };
+ struct device_node *endpoint;
+ int i, nr_lanes, ret;
ret = samsung_dsim_of_read_u32(node, "samsung,pll-clock-frequency",
&dsi->pll_clk_rate);
@@ -1713,6 +1722,22 @@ static int samsung_dsim_parse_dt(struct samsung_dsim *dsi)
if (ret < 0)
return ret;
+ endpoint = of_graph_get_endpoint_by_regs(node, 1, -1);
+ nr_lanes = of_property_count_u32_elems(endpoint, "data-lanes");
+ if (nr_lanes > 0 && nr_lanes <= 4) {
+ /* Polarity 0 is clock lane, 1..4 are data lanes. */
+ of_property_read_u32_array(endpoint, "lane-polarities",
+ lane_polarities, nr_lanes + 1);
+ for (i = 1; i <= nr_lanes; i++) {
+ if (lane_polarities[1] != lane_polarities[i])
+ DRM_DEV_ERROR(dsi->dev, "Data lanes polarities do not match");
+ }
+ if (lane_polarities[0])
+ dsi->swap_dn_dp_clk = true;
+ if (lane_polarities[1])
+ dsi->swap_dn_dp_data = true;
+ }
+
return 0;
}
diff --git a/include/drm/bridge/samsung-dsim.h b/include/drm/bridge/samsung-dsim.h
index ba5484de2b30..6a37d1e079bf 100644
--- a/include/drm/bridge/samsung-dsim.h
+++ b/include/drm/bridge/samsung-dsim.h
@@ -95,6 +95,8 @@ struct samsung_dsim {
u32 mode_flags;
u32 format;
+ bool swap_dn_dp_clk;
+ bool swap_dn_dp_data;
int state;
struct drm_property *brightness;
struct completion completed;
--
2.34.1
