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)
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,
--
2.7.4
