The clock and data lanes of the DSI PHY have a calibration circuitry feature. As per the MSM DSI PHY tuning guidelines, the drive strength tuning can be done by adjusting rescode offset for hstop/hsbot, and the drive level tuning can be done by adjusting the LDO output level for the HSTX drive.
Signed-off-by: Rajeev Nandan quic_rajeevny@quicinc.com ---
Changes in v2: - Split into generic code and 10nm-specific part (Dmitry Baryshkov) - Fix the backward compatibility (Dmitry Baryshkov)
Changes in v3: - Address comments for phy tuning data structure (Dmitry Baryshkov) - Make changes as per updated dt-bindings
Changes in v4: - Return error in case of out of range values (Dmitry Baryshkov) - Return error if dt property is present but parsing is failing
drivers/gpu/drm/msm/dsi/phy/dsi_phy_10nm.c | 118 +++++++++++++++++++++++++++-- 1 file changed, 112 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_10nm.c b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_10nm.c index d8128f5..0a0246c 100644 --- a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_10nm.c +++ b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_10nm.c @@ -83,6 +83,18 @@ struct dsi_pll_10nm {
#define to_pll_10nm(x) container_of(x, struct dsi_pll_10nm, clk_hw)
+/** + * struct dsi_phy_10nm_tuning_cfg - Holds 10nm PHY tuning config parameters. + * @rescode_offset_top: Offset for pull-up legs rescode. + * @rescode_offset_bot: Offset for pull-down legs rescode. + * @vreg_ctrl: vreg ctrl to drive LDO level + */ +struct dsi_phy_10nm_tuning_cfg { + u8 rescode_offset_top[DSI_LANE_MAX]; + u8 rescode_offset_bot[DSI_LANE_MAX]; + u8 vreg_ctrl; +}; + /* * Global list of private DSI PLL struct pointers. We need this for bonded DSI * mode, where the master PLL's clk_ops needs access the slave's private data @@ -747,6 +759,7 @@ static void dsi_phy_hw_v3_0_lane_settings(struct msm_dsi_phy *phy) int i; u8 tx_dctrl[] = { 0x00, 0x00, 0x00, 0x04, 0x01 }; void __iomem *lane_base = phy->lane_base; + struct dsi_phy_10nm_tuning_cfg *tuning_cfg = phy->tuning_cfg;
if (phy->cfg->quirks & DSI_PHY_10NM_QUIRK_OLD_TIMINGS) tx_dctrl[3] = 0x02; @@ -775,10 +788,13 @@ static void dsi_phy_hw_v3_0_lane_settings(struct msm_dsi_phy *phy) dsi_phy_write(lane_base + REG_DSI_10nm_PHY_LN_CFG2(i), 0x0); dsi_phy_write(lane_base + REG_DSI_10nm_PHY_LN_CFG3(i), i == 4 ? 0x80 : 0x0); - dsi_phy_write(lane_base + - REG_DSI_10nm_PHY_LN_OFFSET_TOP_CTRL(i), 0x0); - dsi_phy_write(lane_base + - REG_DSI_10nm_PHY_LN_OFFSET_BOT_CTRL(i), 0x0); + + /* platform specific dsi phy drive strength adjustment */ + dsi_phy_write(lane_base + REG_DSI_10nm_PHY_LN_OFFSET_TOP_CTRL(i), + tuning_cfg->rescode_offset_top[i]); + dsi_phy_write(lane_base + REG_DSI_10nm_PHY_LN_OFFSET_BOT_CTRL(i), + tuning_cfg->rescode_offset_bot[i]); + dsi_phy_write(lane_base + REG_DSI_10nm_PHY_LN_TX_DCTRL(i), tx_dctrl[i]); } @@ -799,6 +815,7 @@ static int dsi_10nm_phy_enable(struct msm_dsi_phy *phy, u32 const timeout_us = 1000; struct msm_dsi_dphy_timing *timing = &phy->timing; void __iomem *base = phy->base; + struct dsi_phy_10nm_tuning_cfg *tuning_cfg = phy->tuning_cfg; u32 data;
DBG(""); @@ -834,8 +851,9 @@ static int dsi_10nm_phy_enable(struct msm_dsi_phy *phy, /* Select MS1 byte-clk */ dsi_phy_write(base + REG_DSI_10nm_PHY_CMN_GLBL_CTRL, 0x10);
- /* Enable LDO */ - dsi_phy_write(base + REG_DSI_10nm_PHY_CMN_VREG_CTRL, 0x59); + /* Enable LDO with platform specific drive level/amplitude adjustment */ + dsi_phy_write(base + REG_DSI_10nm_PHY_CMN_VREG_CTRL, + tuning_cfg->vreg_ctrl);
/* Configure PHY lane swap (TODO: we need to calculate this) */ dsi_phy_write(base + REG_DSI_10nm_PHY_CMN_LANE_CFG0, 0x21); @@ -922,6 +940,92 @@ static void dsi_10nm_phy_disable(struct msm_dsi_phy *phy) DBG("DSI%d PHY disabled", phy->id); }
+static int dsi_10nm_phy_parse_dt(struct msm_dsi_phy *phy) +{ + struct device *dev = &phy->pdev->dev; + struct dsi_phy_10nm_tuning_cfg *tuning_cfg; + s8 offset_top[DSI_LANE_MAX] = { 0 }; /* No offset */ + s8 offset_bot[DSI_LANE_MAX] = { 0 }; /* No offset */ + u32 ldo_level = 400; /* 400mV */ + u8 level; + int ret, i; + + tuning_cfg = devm_kzalloc(dev, sizeof(*tuning_cfg), GFP_KERNEL); + if (!tuning_cfg) + return -ENOMEM; + + /* Drive strength adjustment parameters */ + ret = of_property_read_u8_array(dev->of_node, "qcom,phy-rescode-offset-top", + offset_top, DSI_LANE_MAX); + if (ret && ret != -EINVAL) { + DRM_DEV_ERROR(dev, "failed to parse qcom,phy-rescode-offset-top, %d\n", ret); + return ret; + } + + for (i = 0; i < DSI_LANE_MAX; i++) { + if (offset_top[i] < -32 || offset_top[i] > 31) { + DRM_DEV_ERROR(dev, + "qcom,phy-rescode-offset-top value %d is not in range [-32..31]\n", + offset_top[i]); + return -EINVAL; + } + tuning_cfg->rescode_offset_top[i] = 0x3f & offset_top[i]; + } + + ret = of_property_read_u8_array(dev->of_node, "qcom,phy-rescode-offset-bot", + offset_bot, DSI_LANE_MAX); + if (ret && ret != -EINVAL) { + DRM_DEV_ERROR(dev, "failed to parse qcom,phy-rescode-offset-bot, %d\n", ret); + return ret; + } + + for (i = 0; i < DSI_LANE_MAX; i++) { + if (offset_bot[i] < -32 || offset_bot[i] > 31) { + DRM_DEV_ERROR(dev, + "qcom,phy-rescode-offset-bot value %d is not in range [-32..31]\n", + offset_bot[i]); + return -EINVAL; + } + tuning_cfg->rescode_offset_bot[i] = 0x3f & offset_bot[i]; + } + + /* Drive level/amplitude adjustment parameters */ + ret = of_property_read_u32(dev->of_node, "qcom,phy-drive-ldo-level", &ldo_level); + if (ret && ret != -EINVAL) { + DRM_DEV_ERROR(dev, "failed to parse qcom,phy-drive-ldo-level, %d\n", ret); + return ret; + } + + switch (ldo_level) { + case 375: + level = 0; + break; + case 400: + level = 1; + break; + case 425: + level = 2; + break; + case 450: + level = 3; + break; + case 475: + level = 4; + break; + case 500: + level = 5; + break; + default: + DRM_DEV_ERROR(dev, "qcom,phy-drive-ldo-level %d is not supported\n"); + return -EINVAL; + } + tuning_cfg->vreg_ctrl = 0x58 | (0x7 & level); + + phy->tuning_cfg = tuning_cfg; + + return 0; +} + const struct msm_dsi_phy_cfg dsi_phy_10nm_cfgs = { .has_phy_lane = true, .reg_cfg = { @@ -936,6 +1040,7 @@ const struct msm_dsi_phy_cfg dsi_phy_10nm_cfgs = { .pll_init = dsi_pll_10nm_init, .save_pll_state = dsi_10nm_pll_save_state, .restore_pll_state = dsi_10nm_pll_restore_state, + .parse_dt_properties = dsi_10nm_phy_parse_dt, }, .min_pll_rate = 1000000000UL, .max_pll_rate = 3500000000UL, @@ -957,6 +1062,7 @@ const struct msm_dsi_phy_cfg dsi_phy_10nm_8998_cfgs = { .pll_init = dsi_pll_10nm_init, .save_pll_state = dsi_10nm_pll_save_state, .restore_pll_state = dsi_10nm_pll_restore_state, + .parse_dt_properties = dsi_10nm_phy_parse_dt, }, .min_pll_rate = 1000000000UL, .max_pll_rate = 3500000000UL,