[PATCH v2 16/17] phy: qcom-qmp: Override lane0_power_present signal in device mode

[Manu Gautam]

lane0_power_present signal must be asserted of hardware to
operate properly in SS device mode. On some platforms where VBUS
line is not connected to SS QMP PHY there is SS_PHY_CTRL register
in QSCRATCH wrapper that can be used by software to override VBUS.

Signed-off-by: Manu Gautam <mgau...@codeaurora.org>
---
 drivers/phy/qualcomm/phy-qcom-qmp.c | 38 +++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp.c 
b/drivers/phy/qualcomm/phy-qcom-qmp.c
index d4e1436..1403de3 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp.c
@@ -61,6 +61,9 @@
 #define USB3_MODE                              BIT(0) /* enables USB3 mode */
 #define DP_MODE                                        BIT(1) /* enables DP 
mode */
 
+/* QSCRATCH register bits */
+#define QSCRATCH_SS_PHY_CTRL                   0x30
+#define LANE0_PWR_PRESENT                      BIT(24)
 
 #define PHY_INIT_COMPLETE_TIMEOUT              1000
 #define POWER_DOWN_DELAY_US_MIN                        10
@@ -558,6 +561,7 @@ struct qmp_phy {
  * @dev: device
  * @serdes: iomapped memory space for phy's serdes
  * @dp_com: iomapped memory space for phy's dp_com control block
+ * @qscratch_base: iomapped memory space for qscratch region
  *
  * @clks: array of clocks required by phy
  * @resets: array of resets required by phy
@@ -572,6 +576,7 @@ struct qcom_qmp {
        struct device *dev;
        void __iomem *serdes;
        void __iomem *dp_com;
+       void __iomem *qscratch_base;
 
        struct clk_bulk_data *clks;
        struct reset_control **resets;
@@ -582,6 +587,7 @@ struct qcom_qmp {
 
        struct mutex phy_mutex;
        int init_count;
+       enum phy_mode mode;
 };
 
 static inline void qphy_setbits(void __iomem *base, u32 offset, u32 val)
@@ -1024,6 +1030,26 @@ static int qcom_qmp_phy_exit(struct phy *phy)
        return 0;
 }
 
+static int qcom_qmp_phy_set_mode(struct phy *phy, enum phy_mode mode)
+{
+       struct qmp_phy *qphy = phy_get_drvdata(phy);
+       struct qcom_qmp *qmp = qphy->qmp;
+
+       qmp->mode = mode;
+
+       /* Update VBUS override in qscratch register */
+       if (qmp->qscratch_base) {
+               if (mode == PHY_MODE_USB_DEVICE)
+                       qphy_setbits(qmp->qscratch_base, QSCRATCH_SS_PHY_CTRL,
+                                    LANE0_PWR_PRESENT);
+               else
+                       qphy_clrbits(qmp->qscratch_base, QSCRATCH_SS_PHY_CTRL,
+                                    LANE0_PWR_PRESENT);
+       }
+
+       return 0;
+}
+
 static int qcom_qmp_phy_vreg_init(struct device *dev)
 {
        struct qcom_qmp *qmp = dev_get_drvdata(dev);
@@ -1133,6 +1159,7 @@ static int phy_pipe_clk_register(struct qcom_qmp *qmp, 
struct device_node *np)
 static const struct phy_ops qcom_qmp_phy_gen_ops = {
        .init           = qcom_qmp_phy_init,
        .exit           = qcom_qmp_phy_exit,
+       .set_mode       = qcom_qmp_phy_set_mode,
        .owner          = THIS_MODULE,
 };
 
@@ -1273,7 +1300,18 @@ static int qcom_qmp_phy_probe(struct platform_device 
*pdev)
                qmp->dp_com = base;
        }
 
+       /* Check if platform uses qscratch wrapper */
+       res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "qscratch");
+       if (res) {
+               /* Can't request region as used by other phy and glue drivers */
+               qmp->qscratch_base = devm_ioremap(dev, res->start,
+                                                  resource_size(res));
+               if (IS_ERR(qmp->qscratch_base))
+                       return PTR_ERR(qmp->qscratch_base);
+       }
+
        mutex_init(&qmp->phy_mutex);
+       qmp->mode = PHY_MODE_INVALID;
 
        ret = qcom_qmp_phy_clk_init(dev);
        if (ret)
-- 
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