diff options
| author | Marek Vasut <marex@denx.de> | 2023-05-14 14:46:25 +0300 |
|---|---|---|
| committer | Neil Armstrong <neil.armstrong@linaro.org> | 2023-05-22 16:37:18 +0300 |
| commit | 74629c49e66cc6d36c46ac4e3f059780873ceedf (patch) | |
| tree | eabe74294113b3405b262f8f3baa87958cdca60d /drivers/gpu | |
| parent | ec7743c9c48a14aa884d27f2feee1da30810ce0a (diff) | |
| download | linux-74629c49e66cc6d36c46ac4e3f059780873ceedf.tar.xz | |
drm: bridge: samsung-dsim: Implement support for clock/data polarity swap
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@denx.de>
Signed-off-by: Fabio Estevam <festevam@denx.de>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230514114625.98372-2-festevam@gmail.com
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/bridge/samsung-dsim.c | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c index 10dc3315e69e..0f3f6846beea 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; } |