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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - cpanel.siel.si X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - norik.com X-Get-Message-Sender-Via: cpanel.siel.si: authenticated_id: andrej.picej@norik.com X-Authenticated-Sender: cpanel.siel.si: andrej.picej@norik.com X-Source: X-Source-Args: X-Source-Dir: On 10. 12. 24 12:43, Dmitry Baryshkov wrote: > On Tue, Dec 10, 2024 at 10:19:00AM +0100, Andrej Picej wrote: >> Add a optional properties to change LVDS output voltage. This should not >> be static as this depends mainly on the connected display voltage >> requirement. We have three properties: >> - "ti,lvds-termination-ohms", which sets near end termination, >> - "ti,lvds-vod-swing-data-microvolt" and >> - "ti,lvds-vod-swing-clock-microvolt" which both set LVDS differential >> output voltage for data and clock lanes. They are defined as an array >> with min and max values. The appropriate bitfield will be set if >> selected constraints can be met. >> >> If "ti,lvds-termination-ohms" is not defined the default of 200 Ohm near >> end termination will be used. Selecting only one: >> "ti,lvds-vod-swing-data-microvolt" or >> "ti,lvds-vod-swing-clock-microvolt" can be done, but the output voltage >> constraint for only data/clock lanes will be met. Setting both is >> recommended. >> >> Signed-off-by: Andrej Picej >> --- >> Changes in v5: >> - specify default values in sn65dsi83_parse_lvds_endpoint, >> - move sn65dsi83_parse_lvds_endpoint for channel B up, outside if, >> Changes in v4: >> - fix typo in commit message bitfiled -> bitfield >> - use arrays (lvds_vod_swing_conf and lvds_term_conf) in private data, instead >> of separate variables for channel A/B >> - add more checks on return value of "of_property_read_u32_array" >> Changes in v3: >> - use microvolts for default array values 1000 mV -> 1000000 uV. >> Changes in v2: >> - use datasheet tables to get the proper configuration >> - since major change was done change the authorship to myself >> --- >> drivers/gpu/drm/bridge/ti-sn65dsi83.c | 142 +++++++++++++++++++++++++- >> 1 file changed, 139 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi83.c b/drivers/gpu/drm/bridge/ti-sn65dsi83.c >> index 57a7ed13f996..f9578b38da28 100644 >> --- a/drivers/gpu/drm/bridge/ti-sn65dsi83.c >> +++ b/drivers/gpu/drm/bridge/ti-sn65dsi83.c >> @@ -132,6 +132,16 @@ >> #define REG_IRQ_STAT_CHA_SOT_BIT_ERR BIT(2) >> #define REG_IRQ_STAT_CHA_PLL_UNLOCK BIT(0) >> >> +enum sn65dsi83_channel { >> + CHANNEL_A, >> + CHANNEL_B >> +}; >> + >> +enum sn65dsi83_lvds_term { >> + OHM_100, >> + OHM_200 >> +}; >> + >> enum sn65dsi83_model { >> MODEL_SN65DSI83, >> MODEL_SN65DSI84, >> @@ -147,6 +157,8 @@ struct sn65dsi83 { >> struct regulator *vcc; >> bool lvds_dual_link; >> bool lvds_dual_link_even_odd_swap; >> + int lvds_vod_swing_conf[2]; >> + int lvds_term_conf[2]; >> }; >> >> static const struct regmap_range sn65dsi83_readable_ranges[] = { >> @@ -237,6 +249,36 @@ static const struct regmap_config sn65dsi83_regmap_config = { >> .max_register = REG_IRQ_STAT, >> }; >> >> +static const int lvds_vod_swing_data_table[2][4][2] = { >> + { /* 100 Ohm */ >> + { 180000, 313000 }, >> + { 215000, 372000 }, >> + { 250000, 430000 }, >> + { 290000, 488000 }, >> + }, >> + { /* 200 Ohm */ >> + { 150000, 261000 }, >> + { 200000, 346000 }, >> + { 250000, 428000 }, >> + { 300000, 511000 }, >> + }, >> +}; >> + >> +static const int lvds_vod_swing_clock_table[2][4][2] = { >> + { /* 100 Ohm */ >> + { 140000, 244000 }, >> + { 168000, 290000 }, >> + { 195000, 335000 }, >> + { 226000, 381000 }, >> + }, >> + { /* 200 Ohm */ >> + { 117000, 204000 }, >> + { 156000, 270000 }, >> + { 195000, 334000 }, >> + { 234000, 399000 }, >> + }, >> +}; >> + >> static struct sn65dsi83 *bridge_to_sn65dsi83(struct drm_bridge *bridge) >> { >> return container_of(bridge, struct sn65dsi83, bridge); >> @@ -435,12 +477,16 @@ static void sn65dsi83_atomic_pre_enable(struct drm_bridge *bridge, >> val |= REG_LVDS_FMT_LVDS_LINK_CFG; >> >> regmap_write(ctx->regmap, REG_LVDS_FMT, val); >> - regmap_write(ctx->regmap, REG_LVDS_VCOM, 0x05); >> + regmap_write(ctx->regmap, REG_LVDS_VCOM, >> + REG_LVDS_VCOM_CHA_LVDS_VOD_SWING(ctx->lvds_vod_swing_conf[CHANNEL_A]) | >> + REG_LVDS_VCOM_CHB_LVDS_VOD_SWING(ctx->lvds_vod_swing_conf[CHANNEL_B])); >> regmap_write(ctx->regmap, REG_LVDS_LANE, >> (ctx->lvds_dual_link_even_odd_swap ? >> REG_LVDS_LANE_EVEN_ODD_SWAP : 0) | >> - REG_LVDS_LANE_CHA_LVDS_TERM | >> - REG_LVDS_LANE_CHB_LVDS_TERM); >> + (ctx->lvds_term_conf[CHANNEL_A] ? >> + REG_LVDS_LANE_CHA_LVDS_TERM : 0) | >> + (ctx->lvds_term_conf[CHANNEL_B] ? >> + REG_LVDS_LANE_CHB_LVDS_TERM : 0)); >> regmap_write(ctx->regmap, REG_LVDS_CM, 0x00); >> >> le16val = cpu_to_le16(mode->hdisplay); >> @@ -576,10 +622,100 @@ static const struct drm_bridge_funcs sn65dsi83_funcs = { >> .atomic_get_input_bus_fmts = sn65dsi83_atomic_get_input_bus_fmts, >> }; >> >> +static int sn65dsi83_select_lvds_vod_swing(struct device *dev, >> + u32 lvds_vod_swing_data[2], u32 lvds_vod_swing_clk[2], u8 lvds_term) >> +{ >> + int i; >> + >> + for (i = 0; i <= 3; i++) { >> + if (lvds_vod_swing_data_table[lvds_term][i][0] >= lvds_vod_swing_data[0] && >> + lvds_vod_swing_data_table[lvds_term][i][1] <= lvds_vod_swing_data[1] && >> + lvds_vod_swing_clock_table[lvds_term][i][0] >= lvds_vod_swing_clk[0] && >> + lvds_vod_swing_clock_table[lvds_term][i][1] <= lvds_vod_swing_clk[1]) >> + return i; >> + } >> + >> + dev_err(dev, "failed to find appropriate LVDS_VOD_SWING configuration\n"); >> + return -EINVAL; >> +} >> + >> +static int sn65dsi83_parse_lvds_endpoint(struct sn65dsi83 *ctx, int channel) >> +{ >> + struct device *dev = ctx->dev; >> + struct device_node *endpoint; >> + int endpoint_reg; >> + /* Set so the property can be freely selected if not defined */ >> + u32 lvds_vod_swing_data[2] = { 0, 1000000 }; >> + u32 lvds_vod_swing_clk[2] = { 0, 1000000 }; >> + u32 lvds_term; >> + u8 lvds_term_conf = 0x1; >> + int lvds_vod_swing_conf = 0x1; > > Magic values Can you please elaborate. I can use: u8 lvds_term_conf = OHM_200; What about lvds_vod_swing_conf? Should I create additional define for it? But this doesn't solve a hidden meaning? Maybe additional comment above? Would like to avoid using voltages for it, since then we are reverse engineering the table in datasheet to match the default reg value. > >> + int ret = 0; >> + int ret_data; >> + int ret_clock; >> + >> + if (channel == CHANNEL_A) >> + endpoint_reg = 2; >> + else >> + endpoint_reg = 3; >> + >> + endpoint = of_graph_get_endpoint_by_regs(dev->of_node, endpoint_reg, -1); >> + if (!of_property_read_u32(endpoint, "ti,lvds-termination-ohms", &lvds_term)) { > > The code has been better before: > provide default for lvds_term, read the property (keeping the default in > case of an error), then use the lvds_term to set up lvds_term_conf, as > expected. Ok, will revert back. > >> + if (lvds_term == 100) >> + lvds_term_conf = OHM_100; >> + else >> + lvds_term_conf = OHM_200; >> + } >> + >> + ctx->lvds_term_conf[channel] = lvds_term_conf; >> + >> + ret_data = of_property_read_u32_array(endpoint, >> + "ti,lvds-vod-swing-data-microvolt", lvds_vod_swing_data, >> + ARRAY_SIZE(lvds_vod_swing_data)); >> + if (ret_data != 0 && ret_data != -EINVAL) { >> + ret = ret_data; >> + goto exit; >> + } >> + >> + ret_clock = of_property_read_u32_array(endpoint, >> + "ti,lvds-vod-swing-clock-microvolt", lvds_vod_swing_clk, >> + ARRAY_SIZE(lvds_vod_swing_clk)); >> + if (ret_clock != 0 && ret_clock != -EINVAL) { >> + ret = ret_clock; >> + goto exit; >> + } >> + >> + /* If any of the two properties is defined. */ >> + if (!ret_data || !ret_clock) { >> + lvds_vod_swing_conf = sn65dsi83_select_lvds_vod_swing(dev, >> + lvds_vod_swing_data, lvds_vod_swing_clk, >> + lvds_term_conf); >> + if (lvds_vod_swing_conf < 0) { >> + ret = lvds_vod_swing_conf; >> + goto exit; >> + } >> + } >> + >> + ctx->lvds_vod_swing_conf[channel] = lvds_vod_swing_conf; >> + ret = 0; >> +exit: >> + of_node_put(endpoint); >> + return ret; >> +} >> + >> static int sn65dsi83_parse_dt(struct sn65dsi83 *ctx, enum sn65dsi83_model model) >> { >> struct drm_bridge *panel_bridge; >> struct device *dev = ctx->dev; >> + int ret; >> + >> + ret = sn65dsi83_parse_lvds_endpoint(ctx, CHANNEL_A); >> + if (ret < 0) >> + return ret; >> + >> + ret = sn65dsi83_parse_lvds_endpoint(ctx, CHANNEL_B); >> + if (ret < 0) >> + return ret; >> >> ctx->lvds_dual_link = false; >> ctx->lvds_dual_link_even_odd_swap = false; >> -- >> 2.34.1 >> >