[PATCH v2 3/6] phy: qcom: qmp-usbc: handle CLAMP register in a correct way

[Dmitry Baryshkov]

The QMP USB PHYs on msm8998, qcm2290 and some other platforms don't have
the PCS_MISC_CLAMP_ENABLE register. Instead they need to toggle the
register in the TCSR space. Make the new phy-qcom-qmp-usbc driver
correctly handle the clamp register.

Fixes: a51969fafc82 ("phy: qcom-qmp: Add QMP V3 USB3 PHY support for msm8998")
Fixes: 8abe5e778b2c ("phy: qcom-qmp: Add QCM2290 USB3 PHY support")
Cc: Jeffrey Hugo <quic_jhugo at quicinc.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
---
 drivers/phy/qualcomm/phy-qcom-qmp-usbc.c | 48 ++++++++++++++++++++++++--------
 1 file changed, 37 insertions(+), 11 deletions(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-usbc.c b/drivers/phy/qualcomm/phy-qcom-qmp-usbc.c
index 214cf4203de4..3a4b4849db0f 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-usbc.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-usbc.c
@@ -10,11 +10,13 @@
 #include <linux/io.h>
 #include <linux/iopoll.h>
 #include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
+#include <linux/regmap.h>
 #include <linux/regulator/consumer.h>
 #include <linux/reset.h>
 #include <linux/slab.h>
@@ -56,9 +58,6 @@
 /* QPHY_PCS_LFPS_RXTERM_IRQ_CLEAR register bits */
 #define IRQ_CLEAR				BIT(0)
 
-/* QPHY_V3_PCS_MISC_CLAMP_ENABLE register bits */
-#define CLAMP_EN				BIT(0) /* enables i/o clamp_n */
-
 #define PHY_INIT_COMPLETE_TIMEOUT		10000
 
 struct qmp_phy_init_tbl {
@@ -94,7 +93,6 @@ enum qphy_reg_layout {
 	QPHY_PCS_AUTONOMOUS_MODE_CTRL,
 	QPHY_PCS_LFPS_RXTERM_IRQ_CLEAR,
 	QPHY_PCS_POWER_DOWN_CONTROL,
-	QPHY_PCS_MISC_CLAMP_ENABLE,
 	/* Keep last to ensure regs_layout arrays are properly initialized */
 	QPHY_LAYOUT_SIZE
 };
@@ -106,7 +104,6 @@ static const unsigned int qmp_v3_usb3phy_regs_layout[QPHY_LAYOUT_SIZE] = {
 	[QPHY_PCS_AUTONOMOUS_MODE_CTRL]	= QPHY_V3_PCS_AUTONOMOUS_MODE_CTRL,
 	[QPHY_PCS_LFPS_RXTERM_IRQ_CLEAR] = QPHY_V3_PCS_LFPS_RXTERM_IRQ_CLEAR,
 	[QPHY_PCS_POWER_DOWN_CONTROL]	= QPHY_V3_PCS_POWER_DOWN_CONTROL,
-	[QPHY_PCS_MISC_CLAMP_ENABLE]	= QPHY_V3_PCS_MISC_CLAMP_ENABLE,
 };
 
 static const unsigned int qmp_v3_usb3phy_regs_layout_qcm2290[QPHY_LAYOUT_SIZE] = {
@@ -369,6 +366,9 @@ struct qmp_usbc {
 	void __iomem *tx2;
 	void __iomem *rx2;
 
+	struct regmap *tcsr_map;
+	u32 vls_clamp_reg;
+
 	struct clk *pipe_clk;
 	struct clk_bulk_data *clks;
 	int num_clks;
@@ -691,7 +691,6 @@ static void qmp_usbc_enable_autonomous_mode(struct qmp_usbc *qmp)
 {
 	const struct qmp_phy_cfg *cfg = qmp->cfg;
 	void __iomem *pcs = qmp->pcs;
-	void __iomem *pcs_misc = qmp->pcs_misc;
 	u32 intr_mask;
 
 	if (qmp->mode == PHY_MODE_USB_HOST_SS ||
@@ -712,19 +711,18 @@ static void qmp_usbc_enable_autonomous_mode(struct qmp_usbc *qmp)
 	qphy_setbits(pcs, cfg->regs[QPHY_PCS_AUTONOMOUS_MODE_CTRL], intr_mask);
 
 	/* Enable i/o clamp_n for autonomous mode */
-	if (pcs_misc && cfg->regs[QPHY_PCS_MISC_CLAMP_ENABLE])
-		qphy_clrbits(pcs_misc, cfg->regs[QPHY_PCS_MISC_CLAMP_ENABLE], CLAMP_EN);
+	if (qmp->tcsr_map && qmp->vls_clamp_reg)
+		regmap_write(qmp->tcsr_map, qmp->vls_clamp_reg, 1);
 }
 
 static void qmp_usbc_disable_autonomous_mode(struct qmp_usbc *qmp)
 {
 	const struct qmp_phy_cfg *cfg = qmp->cfg;
 	void __iomem *pcs = qmp->pcs;
-	void __iomem *pcs_misc = qmp->pcs_misc;
 
 	/* Disable i/o clamp_n on resume for normal mode */
-	if (pcs_misc && cfg->regs[QPHY_PCS_MISC_CLAMP_ENABLE])
-		qphy_setbits(pcs_misc, cfg->regs[QPHY_PCS_MISC_CLAMP_ENABLE], CLAMP_EN);
+	if (qmp->tcsr_map && qmp->vls_clamp_reg)
+		regmap_write(qmp->tcsr_map, qmp->vls_clamp_reg, 0);
 
 	qphy_clrbits(pcs, cfg->regs[QPHY_PCS_AUTONOMOUS_MODE_CTRL],
 		     ARCVR_DTCT_EN | ARCVR_DTCT_EVENT_SEL | ALFPS_DTCT_EN);
@@ -1063,6 +1061,30 @@ static int qmp_usbc_parse_dt(struct qmp_usbc *qmp)
 	return 0;
 }
 
+static int qmp_usbc_parse_vls_clamp(struct qmp_usbc *qmp)
+{
+	struct of_phandle_args tcsr_args;
+	struct device *dev = qmp->dev;
+	int ret;
+
+	/*  for backwards compatibility ignore if there is no property */
+	ret = of_parse_phandle_with_fixed_args(dev->of_node, "qcom,tcsr-reg", 1, 0,
+					       &tcsr_args);
+	if (ret == -ENOENT)
+		return 0;
+	else if (ret < 0)
+		return dev_err_probe(dev, ret, "Failed to parse qcom,tcsr-reg\n");
+
+	qmp->tcsr_map = syscon_node_to_regmap(tcsr_args.np);
+	of_node_put(tcsr_args.np);
+	if (IS_ERR(qmp->tcsr_map))
+		return PTR_ERR(qmp->tcsr_map);
+
+	qmp->vls_clamp_reg = tcsr_args.args[0];
+
+	return 0;
+}
+
 static int qmp_usbc_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -1093,6 +1115,10 @@ static int qmp_usbc_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	ret = qmp_usbc_parse_vls_clamp(qmp);
+	if (ret)
+		return ret;
+
 	/* Check for legacy binding with child node. */
 	np = of_get_child_by_name(dev->of_node, "phy");
 	if (np) {

-- 
2.39.2