[RESEND PATCH v1 01/15] phy: Add DisplayPort configuration options

From: Yuti Amonkar
Date: Wed Dec 11 2019 - 08:09:41 EST


Add generic DP API for configuring DisplayPort PHYs. The parameters
that will be configured are link rate, number of lanes, voltage swing
and pre-emphasis.

Signed-off-by: Yuti Amonkar <yamonkar@xxxxxxxxxxx>
---
include/linux/phy/phy-dp.h | 95 ++++++++++++++++++++++++++++++++++++++++++++++
include/linux/phy/phy.h | 4 ++
2 files changed, 99 insertions(+)
create mode 100644 include/linux/phy/phy-dp.h

diff --git a/include/linux/phy/phy-dp.h b/include/linux/phy/phy-dp.h
new file mode 100644
index 0000000..18cad23
--- /dev/null
+++ b/include/linux/phy/phy-dp.h
@@ -0,0 +1,95 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019 Cadence Design Systems Inc.
+ */
+
+#ifndef __PHY_DP_H_
+#define __PHY_DP_H_
+
+#include <linux/types.h>
+
+/**
+ * struct phy_configure_opts_dp - DisplayPort PHY configuration set
+ *
+ * This structure is used to represent the configuration state of a
+ * DisplayPort phy.
+ */
+struct phy_configure_opts_dp {
+ /**
+ * @link_rate:
+ *
+ * Link Rate, in Mb/s, of the main link.
+ *
+ * Allowed values: 1620, 2160, 2430, 2700, 3240, 4320, 5400, 8100 Mb/s
+ */
+ unsigned int link_rate;
+
+ /**
+ * @lanes:
+ *
+ * Number of active, consecutive, data lanes, starting from
+ * lane 0, used for the transmissions on main link.
+ *
+ * Allowed values: 1, 2, 4
+ */
+ unsigned int lanes;
+
+ /**
+ * @voltage:
+ *
+ * Voltage swing levels, as specified by DisplayPort specification,
+ * to be used by particular lanes. One value per lane.
+ * voltage[0] is for lane 0, voltage[1] is for lane 1, etc.
+ *
+ * Maximum value: 3
+ */
+ unsigned int voltage[4];
+
+ /**
+ * @pre:
+ *
+ * Pre-emphasis levels, as specified by DisplayPort specification, to be
+ * used by particular lanes. One value per lane.
+ *
+ * Maximum value: 3
+ */
+ unsigned int pre[4];
+
+ /**
+ * @ssc:
+ *
+ * Flag indicating, whether or not to enable spread-spectrum clocking.
+ *
+ */
+ u8 ssc : 1;
+
+ /**
+ * @set_rate:
+ *
+ * Flag indicating, whether or not reconfigure link rate and SSC to
+ * requested values.
+ *
+ */
+ u8 set_rate : 1;
+
+ /**
+ * @set_lanes:
+ *
+ * Flag indicating, whether or not reconfigure lane count to
+ * requested value.
+ *
+ */
+ u8 set_lanes : 1;
+
+ /**
+ * @set_voltages:
+ *
+ * Flag indicating, whether or not reconfigure voltage swing
+ * and pre-emphasis to requested values. Only lanes specified
+ * by "lanes" parameter will be affected.
+ *
+ */
+ u8 set_voltages : 1;
+};
+
+#endif /* __PHY_DP_H_ */
diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
index 15032f14..ba0aab5 100644
--- a/include/linux/phy/phy.h
+++ b/include/linux/phy/phy.h
@@ -16,6 +16,7 @@
#include <linux/pm_runtime.h>
#include <linux/regulator/consumer.h>

+#include <linux/phy/phy-dp.h>
#include <linux/phy/phy-mipi-dphy.h>

struct phy;
@@ -46,9 +47,12 @@ enum phy_mode {
*
* @mipi_dphy: Configuration set applicable for phys supporting
* the MIPI_DPHY phy mode.
+ * @dp: Configuration set applicable for phys supporting
+ * the DisplayPort protocol.
*/
union phy_configure_opts {
struct phy_configure_opts_mipi_dphy mipi_dphy;
+ struct phy_configure_opts_dp dp;
};

/**
--
2.7.4