diff mbox series

[v1,3/3] PCI: dwc: add rx margining settings for gen4

Message ID 20240301051220.20917-4-quic_schintav@quicinc.com
State New
Headers show
Series Add Gen4 equalization and margining settings | expand

Commit Message

Shashank Babu Chinta Venkata March 1, 2024, 5:11 a.m. UTC 
Add rx margining settings for gen4 operation.

Signed-off-by: Shashank Babu Chinta Venkata <quic_schintav@quicinc.com>
---
 drivers/pci/controller/dwc/pcie-qcom-cmn.c | 36 ++++++++++++++++++++++
 drivers/pci/controller/dwc/pcie-qcom-cmn.h | 34 ++++++++++++++++++++
 drivers/pci/controller/dwc/pcie-qcom-ep.c  |  4 ++-
 drivers/pci/controller/dwc/pcie-qcom.c     |  4 ++-
 4 files changed, 76 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/pci/controller/dwc/pcie-qcom-cmn.c b/drivers/pci/controller/dwc/pcie-qcom-cmn.c
index cfdc04eef78c..abba4de32005 100644
--- a/drivers/pci/controller/dwc/pcie-qcom-cmn.c
+++ b/drivers/pci/controller/dwc/pcie-qcom-cmn.c
@@ -50,6 +50,42 @@  void qcom_pcie_cmn_set_gen4_eq_settings(struct dw_pcie *pci)
 }
 EXPORT_SYMBOL_GPL(qcom_pcie_cmn_set_gen4_eq_settings);
 
+void qcom_pcie_cmn_set_gen4_rx_margining_settings(struct dw_pcie *pci)
+{
+	u32 reg;
+
+	reg = dw_pcie_readl_dbi(pci, GEN4_LANE_MARGINING_1_OFF);
+	reg &= ~MARGINING_MAX_VOLTAGE_OFFSET_MASK;
+	reg |= (MARGINING_MAX_VOLTAGE_OFFSET_VAL <<
+		MARGINING_MAX_VOLTAGE_OFFSET_SHIFT);
+	reg &= ~MARGINING_NUM_VOLTAGE_STEPS_MASK;
+	reg |= (MARGINING_NUM_VOLTAGE_STEPS_VAL <<
+		MARGINING_NUM_VOLTAGE_STEPS_SHIFT);
+	reg &= ~MARGINING_MAX_TIMING_OFFSET_MASK;
+	reg |= (MARGINING_MAX_TIMING_OFFSET_VAL <<
+		MARGINING_MAX_TIMING_OFFSET_SHIFT);
+	reg &= ~MARGINING_NUM_TIMING_STEPS_MASK;
+	reg |= MARGINING_NUM_TIMING_STEPS_VAL;
+	dw_pcie_writel_dbi(pci, GEN4_LANE_MARGINING_1_OFF, reg);
+
+
+	reg = dw_pcie_readl_dbi(pci, GEN4_LANE_MARGINING_2_OFF);
+	reg |= MARGINING_IND_ERROR_SAMPLER;
+	reg |= MARGINING_SAMPLE_REPORTING_METHOD;
+	reg |= MARGINING_IND_LEFT_RIGHT_TIMING;
+	reg |= MARGINING_VOLTAGE_SUPPORTED;
+	reg &= ~MARGINING_IND_UP_DOWN_VOLTAGE;
+	reg &= ~MARGINING_MAXLANES_MASK;
+	reg |= (pci->num_lanes <<
+		MARGINING_MAXLANES_SHIFT);
+	reg &= ~MARGINING_SAMPLE_RATE_TIMING_MASK;
+	reg |= (MARGINING_SAMPLE_RATE_TIMING_VAL <<
+		MARGINING_SAMPLE_RATE_TIMING_SHIFT);
+	reg |= MARGINING_SAMPLE_RATE_VOLTAGE_VAL;
+	dw_pcie_writel_dbi(pci, GEN4_LANE_MARGINING_2_OFF, reg);
+}
+EXPORT_SYMBOL_GPL(qcom_pcie_cmn_set_gen4_rx_margining_settings);
+
 int qcom_pcie_cmn_icc_get_resource(struct dw_pcie *pci, struct icc_path *icc_mem)
 {
 	int ret = 0;
diff --git a/drivers/pci/controller/dwc/pcie-qcom-cmn.h b/drivers/pci/controller/dwc/pcie-qcom-cmn.h
index 08e1bd179207..b145743a7558 100644
--- a/drivers/pci/controller/dwc/pcie-qcom-cmn.h
+++ b/drivers/pci/controller/dwc/pcie-qcom-cmn.h
@@ -27,11 +27,40 @@ 
 #define GEN3_EQ_FMDC_MAX_PRE_CUSROR_DELTA_SHIFT		10
 #define GEN3_EQ_FMDC_MAX_POST_CUSROR_DELTA_SHIFT	14
 
+#define GEN4_LANE_MARGINING_1_OFF		0xb80
+#define GEN4_LANE_MARGINING_2_OFF		0xb84
+
+#define MARGINING_MAX_VOLTAGE_OFFSET_MASK	GENMASK(29, 24)
+#define MARGINING_NUM_VOLTAGE_STEPS_MASK	GENMASK(22, 16)
+#define MARGINING_MAX_TIMING_OFFSET_MASK	GENMASK(13, 8)
+#define MARGINING_NUM_TIMING_STEPS_MASK		GENMASK(5, 0)
+#define MARGINING_MAX_VOLTAGE_OFFSET_SHIFT	24
+#define MARGINING_NUM_VOLTAGE_STEPS_SHIFT	16
+#define MARGINING_MAX_TIMING_OFFSET_SHIFT	8
+#define MARGINING_MAX_VOLTAGE_OFFSET_VAL	0x24
+#define MARGINING_NUM_VOLTAGE_STEPS_VAL		0x78
+#define MARGINING_MAX_TIMING_OFFSET_VAL		0x32
+#define MARGINING_NUM_TIMING_STEPS_VAL		0x10
+
+#define MARGINING_IND_ERROR_SAMPLER		BIT(28)
+#define MARGINING_SAMPLE_REPORTING_METHOD	BIT(27)
+#define MARGINING_IND_LEFT_RIGHT_TIMING		BIT(26)
+#define MARGINING_IND_UP_DOWN_VOLTAGE		BIT(25)
+#define MARGINING_VOLTAGE_SUPPORTED		BIT(24)
+#define MARGINING_MAXLANES_MASK			GENMASK(20, 16)
+#define MARGINING_SAMPLE_RATE_TIMING_MASK	GENMASK(13, 8)
+#define MARGINING_SAMPLE_RATE_VOLTAGE_MASK	GENMASK(5, 0)
+#define MARGINING_MAXLANES_SHIFT		16
+#define MARGINING_SAMPLE_RATE_TIMING_SHIFT	8
+#define MARGINING_SAMPLE_RATE_TIMING_VAL	0x3f
+#define MARGINING_SAMPLE_RATE_VOLTAGE_VAL	0x3f
+
 #ifdef CONFIG_PCIE_QCOM_CMN
 int qcom_pcie_cmn_icc_get_resource(struct dw_pcie *pci, struct icc_path *icc_mem);
 int qcom_pcie_cmn_icc_init(struct dw_pcie *pci, struct icc_path *icc_mem);
 void qcom_pcie_cmn_icc_update(struct dw_pcie *pci, struct icc_path *icc_mem);
 void qcom_pcie_cmn_set_gen4_eq_settings(struct dw_pcie *pci);
+void qcom_pcie_cmn_set_gen4_rx_margining_settings(struct dw_pcie *pci);
 #else
 static inline int qcom_pcie_cmn_icc_get_resource(struct dw_pcie *pci, struct icc_path *icc_mem)
 {
@@ -50,4 +79,9 @@  static inline void qcom_pcie_cmn_icc_update(struct dw_pcie *pci, struct icc_path
 static inline void qcom_pcie_cmn_set_gen4_eq_settings(struct dw_pcie *pci)
 {
 }
+
+static inline void qcom_pcie_cmn_set_gen4_rx_margining_settings(struct dw_pcie *pci)
+{
+}
+
 #endif
diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c
index 0b169bcd081d..5422fa970d9d 100644
--- a/drivers/pci/controller/dwc/pcie-qcom-ep.c
+++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c
@@ -439,8 +439,10 @@  static int qcom_pcie_perst_deassert(struct dw_pcie *pci)
 	}
 
 	/* set Gen4 equalization settings */
-	if (pci->link_gen == 4)
+	if (pci->link_gen == 4) {
 		qcom_pcie_cmn_set_gen4_eq_settings(pci);
+		qcom_pcie_cmn_set_gen4_rx_margining_settings(pci);
+	}
 
 	/*
 	 * The physical address of the MMIO region which is exposed as the BAR
diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index ad0cd55da777..3ada1e9fdd11 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -264,8 +264,10 @@  static int qcom_pcie_start_link(struct dw_pcie *pci)
 	struct qcom_pcie *pcie = to_qcom_pcie(pci);
 
 	/* set Gen4 equalization settings */
-	if (pci->link_gen == 4)
+	if (pci->link_gen == 4) {
 		qcom_pcie_cmn_set_gen4_eq_settings(pci);
+		qcom_pcie_cmn_set_gen4_rx_margining_settings(pci);
+	}
 
 	/* Enable Link Training state machine */
 	if (pcie->cfg->ops->ltssm_enable)