| Message ID | 20241203110054.2506123-3-andrej.picej@norik.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | SN65DSI83/4 lvds_vod_swing properties | expand |
On Tue, Dec 03, 2024 at 12:00:53PM +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 bitfiled 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 <andrej.picej@norik.com> > --- > 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 | 144 +++++++++++++++++++++++++- > 1 file changed, 141 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi83.c b/drivers/gpu/drm/bridge/ti-sn65dsi83.c > index 57a7ed13f996..1a070df5ea12 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 +157,10 @@ struct sn65dsi83 { > struct regulator *vcc; > bool lvds_dual_link; > bool lvds_dual_link_even_odd_swap; > + int lvdsA_vod_swing_conf; > + int lvdsB_vod_swing_conf; > + int lvdsA_term_conf; > + int lvdsB_term_conf; > }; > > static const struct regmap_range sn65dsi83_readable_ranges[] = { > @@ -237,6 +251,36 @@ 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 +479,16 @@ 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->lvdsA_vod_swing_conf) | > + REG_LVDS_VCOM_CHB_LVDS_VOD_SWING(ctx->lvdsB_vod_swing_conf)); > 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->lvdsA_term_conf ? > + REG_LVDS_LANE_CHA_LVDS_TERM : 0) | > + (ctx->lvdsB_term_conf ? > + REG_LVDS_LANE_CHB_LVDS_TERM : 0)); > regmap_write(ctx->regmap, REG_LVDS_CM, 0x00); > > le16val = cpu_to_le16(mode->hdisplay); > @@ -576,10 +624,96 @@ 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; > + /* 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 = 200; > + u8 lvds_term_conf; > + int endpoint_reg; > + int lvds_vod_swing_conf; > + 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); > + of_property_read_u32(endpoint, "ti,lvds-termination-ohms", &lvds_term); > + > + if (lvds_term == 200) > + lvds_term_conf = OHM_200; > + else > + lvds_term_conf = OHM_100; > + > + if (channel == CHANNEL_A) > + ctx->lvdsA_term_conf = lvds_term_conf; > + else > + ctx->lvdsB_term_conf = lvds_term_conf; This sounds like ctx->lvds_term_conf[channel] = ...; And so on for other properties. > + > + ret_data = of_property_read_u32_array(endpoint, > + "ti,lvds-vod-swing-data-microvolt", lvds_vod_swing_data, > + ARRAY_SIZE(lvds_vod_swing_data)); > + 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 any of the two properties is defined. */ > + if (!ret_data || !ret_clock) { I think it's not that easy. We were usually ignoring errors for a single-value properties, but for the arrays I think we should make a diffence between the property being not present in DT and the property being erroneous or not being parsed correctly. > + 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; > + } > + if (channel == CHANNEL_A) > + ctx->lvdsA_vod_swing_conf = lvds_vod_swing_conf; > + else > + ctx->lvdsB_vod_swing_conf = 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; > + > + ctx->lvdsA_vod_swing_conf = 0x1; > + ctx->lvdsB_vod_swing_conf = 0x1; > + ctx->lvdsA_term_conf = 0x1; > + ctx->lvdsB_term_conf = 0x1; > + > + ret = sn65dsi83_parse_lvds_endpoint(ctx, CHANNEL_A); > + if (ret < 0) > + return ret; > > ctx->lvds_dual_link = false; > ctx->lvds_dual_link_even_odd_swap = false; > @@ -587,6 +721,10 @@ static int sn65dsi83_parse_dt(struct sn65dsi83 *ctx, enum sn65dsi83_model model) > struct device_node *port2, *port3; > int dual_link; > > + ret = sn65dsi83_parse_lvds_endpoint(ctx, CHANNEL_B); > + if (ret < 0) > + return ret; > + > port2 = of_graph_get_port_by_id(dev->of_node, 2); > port3 = of_graph_get_port_by_id(dev->of_node, 3); > dual_link = drm_of_lvds_get_dual_link_pixel_order(port2, port3); > -- > 2.34.1 >
Hi Dmitry, On 3. 12. 24 18:26, Dmitry Baryshkov wrote: > On Tue, Dec 03, 2024 at 12:00:53PM +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 bitfiled 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 <andrej.picej@norik.com> >> --- >> 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 | 144 +++++++++++++++++++++++++- >> 1 file changed, 141 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi83.c b/drivers/gpu/drm/bridge/ti-sn65dsi83.c >> index 57a7ed13f996..1a070df5ea12 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 +157,10 @@ struct sn65dsi83 { >> struct regulator *vcc; >> bool lvds_dual_link; >> bool lvds_dual_link_even_odd_swap; >> + int lvdsA_vod_swing_conf; >> + int lvdsB_vod_swing_conf; >> + int lvdsA_term_conf; >> + int lvdsB_term_conf; >> }; >> >> static const struct regmap_range sn65dsi83_readable_ranges[] = { >> @@ -237,6 +251,36 @@ 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 +479,16 @@ 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->lvdsA_vod_swing_conf) | >> + REG_LVDS_VCOM_CHB_LVDS_VOD_SWING(ctx->lvdsB_vod_swing_conf)); >> 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->lvdsA_term_conf ? >> + REG_LVDS_LANE_CHA_LVDS_TERM : 0) | >> + (ctx->lvdsB_term_conf ? >> + REG_LVDS_LANE_CHB_LVDS_TERM : 0)); >> regmap_write(ctx->regmap, REG_LVDS_CM, 0x00); >> >> le16val = cpu_to_le16(mode->hdisplay); >> @@ -576,10 +624,96 @@ 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; >> + /* 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 = 200; >> + u8 lvds_term_conf; >> + int endpoint_reg; >> + int lvds_vod_swing_conf; >> + 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); >> + of_property_read_u32(endpoint, "ti,lvds-termination-ohms", &lvds_term); >> + >> + if (lvds_term == 200) >> + lvds_term_conf = OHM_200; >> + else >> + lvds_term_conf = OHM_100; >> + >> + if (channel == CHANNEL_A) >> + ctx->lvdsA_term_conf = lvds_term_conf; >> + else >> + ctx->lvdsB_term_conf = lvds_term_conf; > > This sounds like ctx->lvds_term_conf[channel] = ...; > > And so on for other properties. correct, this might simplify the code. Will include it in next patch iteration. > >> + >> + ret_data = of_property_read_u32_array(endpoint, >> + "ti,lvds-vod-swing-data-microvolt", lvds_vod_swing_data, >> + ARRAY_SIZE(lvds_vod_swing_data)); >> + 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 any of the two properties is defined. */ >> + if (!ret_data || !ret_clock) { > > I think it's not that easy. We were usually ignoring errors for a > single-value properties, but for the arrays I think we should make a > diffence between the property being not present in DT and the property > being erroneous or not being parsed correctly. Ok, no problem. I'll add additional checks on return values and err out if return value is anything else then 0 or -EINVAL. Best regards, Andrej > >> + 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; >> + } >> + if (channel == CHANNEL_A) >> + ctx->lvdsA_vod_swing_conf = lvds_vod_swing_conf; >> + else >> + ctx->lvdsB_vod_swing_conf = 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; >> + >> + ctx->lvdsA_vod_swing_conf = 0x1; >> + ctx->lvdsB_vod_swing_conf = 0x1; >> + ctx->lvdsA_term_conf = 0x1; >> + ctx->lvdsB_term_conf = 0x1; >> + >> + ret = sn65dsi83_parse_lvds_endpoint(ctx, CHANNEL_A); >> + if (ret < 0) >> + return ret; >> >> ctx->lvds_dual_link = false; >> ctx->lvds_dual_link_even_odd_swap = false; >> @@ -587,6 +721,10 @@ static int sn65dsi83_parse_dt(struct sn65dsi83 *ctx, enum sn65dsi83_model model) >> struct device_node *port2, *port3; >> int dual_link; >> >> + ret = sn65dsi83_parse_lvds_endpoint(ctx, CHANNEL_B); >> + if (ret < 0) >> + return ret; >> + >> port2 = of_graph_get_port_by_id(dev->of_node, 2); >> port3 = of_graph_get_port_by_id(dev->of_node, 3); >> dual_link = drm_of_lvds_get_dual_link_pixel_order(port2, port3); >> -- >> 2.34.1 >> >
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi83.c b/drivers/gpu/drm/bridge/ti-sn65dsi83.c index 57a7ed13f996..1a070df5ea12 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 +157,10 @@ struct sn65dsi83 { struct regulator *vcc; bool lvds_dual_link; bool lvds_dual_link_even_odd_swap; + int lvdsA_vod_swing_conf; + int lvdsB_vod_swing_conf; + int lvdsA_term_conf; + int lvdsB_term_conf; }; static const struct regmap_range sn65dsi83_readable_ranges[] = { @@ -237,6 +251,36 @@ 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 +479,16 @@ 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->lvdsA_vod_swing_conf) | + REG_LVDS_VCOM_CHB_LVDS_VOD_SWING(ctx->lvdsB_vod_swing_conf)); 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->lvdsA_term_conf ? + REG_LVDS_LANE_CHA_LVDS_TERM : 0) | + (ctx->lvdsB_term_conf ? + REG_LVDS_LANE_CHB_LVDS_TERM : 0)); regmap_write(ctx->regmap, REG_LVDS_CM, 0x00); le16val = cpu_to_le16(mode->hdisplay); @@ -576,10 +624,96 @@ 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; + /* 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 = 200; + u8 lvds_term_conf; + int endpoint_reg; + int lvds_vod_swing_conf; + 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); + of_property_read_u32(endpoint, "ti,lvds-termination-ohms", &lvds_term); + + if (lvds_term == 200) + lvds_term_conf = OHM_200; + else + lvds_term_conf = OHM_100; + + if (channel == CHANNEL_A) + ctx->lvdsA_term_conf = lvds_term_conf; + else + ctx->lvdsB_term_conf = 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)); + 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 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; + } + if (channel == CHANNEL_A) + ctx->lvdsA_vod_swing_conf = lvds_vod_swing_conf; + else + ctx->lvdsB_vod_swing_conf = 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; + + ctx->lvdsA_vod_swing_conf = 0x1; + ctx->lvdsB_vod_swing_conf = 0x1; + ctx->lvdsA_term_conf = 0x1; + ctx->lvdsB_term_conf = 0x1; + + ret = sn65dsi83_parse_lvds_endpoint(ctx, CHANNEL_A); + if (ret < 0) + return ret; ctx->lvds_dual_link = false; ctx->lvds_dual_link_even_odd_swap = false; @@ -587,6 +721,10 @@ static int sn65dsi83_parse_dt(struct sn65dsi83 *ctx, enum sn65dsi83_model model) struct device_node *port2, *port3; int dual_link; + ret = sn65dsi83_parse_lvds_endpoint(ctx, CHANNEL_B); + if (ret < 0) + return ret; + port2 = of_graph_get_port_by_id(dev->of_node, 2); port3 = of_graph_get_port_by_id(dev->of_node, 3); dual_link = drm_of_lvds_get_dual_link_pixel_order(port2, port3);
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 bitfiled 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 <andrej.picej@norik.com> --- 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 | 144 +++++++++++++++++++++++++- 1 file changed, 141 insertions(+), 3 deletions(-)