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@xxxxxxxxxxx>
---
Changes in v2:
- Split into generic code and 10nm-specific part (Dmitry Baryshkov)
- Fix the backward compatibility (Dmitry Baryshkov)
drivers/gpu/drm/msm/dsi/phy/dsi_phy_10nm.c | 51 ++++++++++++++++++++++++++----
1 file changed, 45 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..40cd0f7 100644
--- a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_10nm.c
+++ b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_10nm.c
@@ -775,10 +775,13 @@ 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),
+ phy->tuning_cfg.rescode_offset_top[i]);
+ dsi_phy_write(lane_base + REG_DSI_10nm_PHY_LN_OFFSET_BOT_CTRL(i),
+ phy->tuning_cfg.rescode_offset_bot[i]);
+
dsi_phy_write(lane_base + REG_DSI_10nm_PHY_LN_TX_DCTRL(i),
tx_dctrl[i]);
}
@@ -834,8 +837,9 @@ 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,
+ phy->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 +926,39 @@ static void dsi_10nm_phy_disable(struct msm_dsi_phy *phy)
DBG("DSI%d PHY disabled", phy->id);
}
+static void dsi_10nm_phy_tuning_cfg_init(struct msm_dsi_phy *phy)
+{
+ struct device *dev = &phy->pdev->dev;
+ u8 offset_top[DSI_LANE_MAX] = { 0 }; /* No offset */
+ u8 offset_bot[DSI_LANE_MAX] = { 0 }; /* No offset */
+ u8 ldo_level = 0x1; /* 400mV */
+ int ret, i;
+
+ /* Drive strength adjustment parameters */
+ ret = of_property_read_u8_array(dev->of_node, "phy-resocde-offset-top",
+ offset_top, DSI_LANE_MAX);
+ if (ret && ret != -EINVAL)
+ DRM_DEV_ERROR(dev, "failed to parse phy-resocde-offset-top, %d\n", ret);
+
+ for (i = 0; i < DSI_LANE_MAX; i++)
+ phy->tuning_cfg.rescode_offset_top[i] = 0x3f & offset_top[i];
+
+ ret = of_property_read_u8_array(dev->of_node, "phy-resocde-offset-bot",
+ offset_bot, DSI_LANE_MAX);
+ if (ret && ret != -EINVAL)
+ DRM_DEV_ERROR(dev, "failed to parse phy-resocde-offset-bot, %d\n", ret);
+
+ for (i = 0; i < DSI_LANE_MAX; i++)
+ phy->tuning_cfg.rescode_offset_bot[i] = 0x3f & offset_bot[i];
+
+ /* Drive level/amplitude adjustment parameters */
+ ret = of_property_read_u8(dev->of_node, "phy-drive-ldo-level", &ldo_level);
+ if (ret && ret != -EINVAL)
+ DRM_DEV_ERROR(dev, "failed to parse phy-drive-ldo-level, %d\n", ret);
+
+ phy->tuning_cfg.vreg_ctrl = 0x58 | (0x7 & ldo_level);
+}
+
const struct msm_dsi_phy_cfg dsi_phy_10nm_cfgs = {
.has_phy_lane = true,
.reg_cfg = {
@@ -936,6 +973,7 @@ 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,
+ .tuning_cfg_init = dsi_10nm_phy_tuning_cfg_init,
},
.min_pll_rate = 1000000000UL,
.max_pll_rate = 3500000000UL,
@@ -957,6 +995,7 @@ 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,
+ .tuning_cfg_init = dsi_10nm_phy_tuning_cfg_init,
},
.min_pll_rate = 1000000000UL,
.max_pll_rate = 3500000000UL,
--
2.7.4
