[PATCH v5 0/5] phy: phy-fsl-imx8-mipi-dphy: Add i.MX8qxp LVDS PHY mode support

[PATCH v5 0/5] phy: phy-fsl-imx8-mipi-dphy: Add i.MX8qxp LVDS PHY mode support

[Liu Ying]

Hi,

This series adds i.MX8qxp LVDS PHY mode support for the Mixel PHY in the
Freescale i.MX8qxp SoC.

The Mixel PHY is MIPI DPHY + LVDS PHY combo, which can works in either
MIPI DPHY mode or LVDS PHY mode.  The PHY mode is controlled by i.MX8qxp
SCU firmware.  The PHY driver would call a SCU function to configure the
mode.

The PHY driver is already supporting the Mixel MIPI DPHY in i.MX8mq SoC,
where it appears to be a single MIPI DPHY.


Patch 1/5 sets PHY mode in the Northwest Logic MIPI DSI host controller
bridge driver, since i.MX8qxp SoC embeds this controller IP to support
MIPI DSI displays together with the Mixel PHY.

Patch 2/5 allows LVDS PHYs to be configured through the generic PHY functions
and through a custom structure added to the generic PHY configuration union.

Patch 3/5 converts mixel,mipi-dsi-phy plain text dt binding to json-schema.

Patch 4/5 adds dt binding support for the Mixel combo PHY in i.MX8qxp SoC.

Patch 5/5 adds the i.MX8qxp LVDS PHY mode support in the Mixel PHY driver.


Welcome comments, thanks.

v4->v5:
* Align kernel-doc style of include/linux/phy/phy-lvds.h to
  include/linux/phy/phy.h for patch 2/5. (Vinod)
* Trivial tweaks on patch 2/5.
* Drop Robert's R-b tag on patch 2/5.

v3->v4:
* Add all R-b tags received from v3 on relevant patches and respin. (Robert)

v2->v3:
* Improve readability of mixel_dphy_set_mode() in the Mixel PHY driver. (Guido)
* Improve the 'clock-names' property in the PHY dt binding.

v1->v2:
* Convert mixel,mipi-dsi-phy plain text dt binding to json-schema. (Guido)
* Print invalid PHY mode in dmesg from the Mixel PHY driver. (Guido)
* Add Guido's R-b tag on the patch for the nwl-dsi drm bridge driver.

Liu Ying (5):
  drm/bridge: nwl-dsi: Set PHY mode in nwl_dsi_enable()
  phy: Add LVDS configuration options
  dt-bindings: phy: Convert mixel,mipi-dsi-phy to json-schema
  dt-bindings: phy: mixel: mipi-dsi-phy: Add Mixel combo PHY support for
    i.MX8qxp
  phy: freescale: phy-fsl-imx8-mipi-dphy: Add i.MX8qxp LVDS PHY mode
    support

 .../devicetree/bindings/phy/mixel,mipi-dsi-phy.txt |  29 ---
 .../bindings/phy/mixel,mipi-dsi-phy.yaml           | 107 ++++++++
 drivers/gpu/drm/bridge/nwl-dsi.c                   |   6 +
 drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c     | 269 ++++++++++++++++++++-
 include/linux/phy/phy-lvds.h                       |  32 +++
 include/linux/phy/phy.h                            |   4 +
 6 files changed, 407 insertions(+), 40 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/phy/mixel,mipi-dsi-phy.txt
 create mode 100644 Documentation/devicetree/bindings/phy/mixel,mipi-dsi-phy.yaml
 create mode 100644 include/linux/phy/phy-lvds.h

-- 
2.7.4

[PATCH v5 1/5] drm/bridge: nwl-dsi: Set PHY mode in nwl_dsi_enable()

[Liu Ying]

The Northwest Logic MIPI DSI host controller embedded in i.MX8qxp
works with a Mixel MIPI DPHY + LVDS PHY combo to support either
a MIPI DSI display or a LVDS display.  So, this patch calls
phy_set_mode() from nwl_dsi_enable() to set PHY mode to MIPI DPHY
explicitly.

Cc: Guido Günther <agx@sigxcpu.org>
Cc: Robert Chiras <robert.chiras@nxp.com>
Cc: Martin Kepplinger <martin.kepplinger@puri.sm>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Jonas Karlman <jonas@kwiboo.se>
Cc: Jernej Skrabec <jernej.skrabec@siol.net>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: NXP Linux Team <linux-imx@nxp.com>
Reviewed-by: Guido Günther <agx@sigxcpu.org>
Signed-off-by: Liu Ying <victor.liu@nxp.com>
---
v4->v5:
* No change.

v3->v4:
* No change.

v2->v3:
* No change.

v1->v2:
* Add Guido's R-b tag.

 drivers/gpu/drm/bridge/nwl-dsi.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/bridge/nwl-dsi.c b/drivers/gpu/drm/bridge/nwl-dsi.c
index 66b6740..be6bfc5 100644
--- a/drivers/gpu/drm/bridge/nwl-dsi.c
+++ b/drivers/gpu/drm/bridge/nwl-dsi.c
@@ -678,6 +678,12 @@ static int nwl_dsi_enable(struct nwl_dsi *dsi)
 		return ret;
 	}
 
+	ret = phy_set_mode(dsi->phy, PHY_MODE_MIPI_DPHY);
+	if (ret < 0) {
+		DRM_DEV_ERROR(dev, "Failed to set DSI phy mode: %d\n", ret);
+		goto uninit_phy;
+	}
+
 	ret = phy_configure(dsi->phy, phy_cfg);
 	if (ret < 0) {
 		DRM_DEV_ERROR(dev, "Failed to configure DSI phy: %d\n", ret);
-- 
2.7.4

[PATCH v5 2/5] phy: Add LVDS configuration options

[Liu Ying]

This patch allows LVDS PHYs to be configured through
the generic functions and through a custom structure
added to the generic union.

The parameters added here are based on common LVDS PHY
implementation practices.  The set of parameters
should cover all potential users.

Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: NXP Linux Team <linux-imx@nxp.com>
Signed-off-by: Liu Ying <victor.liu@nxp.com>
---
v4->v5:
* Align kernel-doc style to include/linux/phy/phy.h. (Vinod)
* Trivial tweaks.
* Drop Robert's R-b tag.

v3->v4:
* Add Robert's R-b tag.

v2->v3:
* No change.

v1->v2:
* No change.

 include/linux/phy/phy-lvds.h | 32 ++++++++++++++++++++++++++++++++
 include/linux/phy/phy.h      |  4 ++++
 2 files changed, 36 insertions(+)
 create mode 100644 include/linux/phy/phy-lvds.h

diff --git a/include/linux/phy/phy-lvds.h b/include/linux/phy/phy-lvds.h
new file mode 100644
index 00000000..7a2f474
--- /dev/null
+++ b/include/linux/phy/phy-lvds.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright 2020 NXP
+ */
+
+#ifndef __PHY_LVDS_H_
+#define __PHY_LVDS_H_
+
+/**
+ * struct phy_configure_opts_lvds - LVDS configuration set
+ * @bits_per_lane_and_dclk_cycle:	Number of bits per data lane and
+ *					differential clock cycle.
+ * @differential_clk_rate:		Clock rate, in Hertz, of the LVDS
+ *					differential clock.
+ * @lanes:				Number of active, consecutive,
+ *					data lanes, starting from lane 0,
+ *					used for the transmissions.
+ * @is_slave:				Boolean, true if the phy is a slave
+ *					which works together with a master
+ *					phy to support dual link transmission,
+ *					otherwise a regular phy or a master phy.
+ *
+ * This structure is used to represent the configuration state of a LVDS phy.
+ */
+struct phy_configure_opts_lvds {
+	unsigned int	bits_per_lane_and_dclk_cycle;
+	unsigned long	differential_clk_rate;
+	unsigned int	lanes;
+	bool		is_slave;
+};
+
+#endif /* __PHY_LVDS_H_ */
diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
index e435bdb..d450b44 100644
--- a/include/linux/phy/phy.h
+++ b/include/linux/phy/phy.h
@@ -17,6 +17,7 @@
 #include <linux/regulator/consumer.h>
 
 #include <linux/phy/phy-dp.h>
+#include <linux/phy/phy-lvds.h>
 #include <linux/phy/phy-mipi-dphy.h>
 
 struct phy;
@@ -51,10 +52,13 @@ enum phy_mode {
  *		the MIPI_DPHY phy mode.
  * @dp:		Configuration set applicable for phys supporting
  *		the DisplayPort protocol.
+ * @lvds:	Configuration set applicable for phys supporting
+ *		the LVDS phy mode.
  */
 union phy_configure_opts {
 	struct phy_configure_opts_mipi_dphy	mipi_dphy;
 	struct phy_configure_opts_dp		dp;
+	struct phy_configure_opts_lvds		lvds;
 };
 
 /**
-- 
2.7.4

[PATCH v5 3/5] dt-bindings: phy: Convert mixel,mipi-dsi-phy to json-schema

[Liu Ying]

This patch converts the mixel,mipi-dsi-phy binding to
DT schema format using json-schema.

Comparing to the plain text version, the new binding adds
the 'assigned-clocks', 'assigned-clock-parents' and
'assigned-clock-rates' properites, otherwise 'make dtbs_check'
would complain that there are mis-matches.  Also, the new
binding requires the 'power-domains' property since all potential
SoCs that embed this PHY would provide a power domain for it.
The example of the new binding takes reference to the latest
dphy node in imx8mq.dtsi.

Cc: Guido Günther <agx@sigxcpu.org>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: NXP Linux Team <linux-imx@nxp.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Guido Günther <agx@sigxcpu.org>
Signed-off-by: Liu Ying <victor.liu@nxp.com>
---
v4->v5:
* No change.

v3->v4:
* Add Rob's and Guido's R-b tags.

v2->v3:
* Improve the 'clock-names' property by dropping 'items:'.

v1->v2:
* Newly introduced in v2.  (Guido)

 .../devicetree/bindings/phy/mixel,mipi-dsi-phy.txt | 29 ---------
 .../bindings/phy/mixel,mipi-dsi-phy.yaml           | 72 ++++++++++++++++++++++
 2 files changed, 72 insertions(+), 29 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/phy/mixel,mipi-dsi-phy.txt
 create mode 100644 Documentation/devicetree/bindings/phy/mixel,mipi-dsi-phy.yaml

diff --git a/Documentation/devicetree/bindings/phy/mixel,mipi-dsi-phy.txt b/Documentation/devicetree/bindings/phy/mixel,mipi-dsi-phy.txt
deleted file mode 100644
index 9b23407..00000000
--- a/Documentation/devicetree/bindings/phy/mixel,mipi-dsi-phy.txt
+++ /dev/null
@@ -1,29 +0,0 @@
-Mixel DSI PHY for i.MX8
-
-The Mixel MIPI-DSI PHY IP block is e.g. found on i.MX8 platforms (along the
-MIPI-DSI IP from Northwest Logic). It represents the physical layer for the
-electrical signals for DSI.
-
-Required properties:
-- compatible: Must be:
-  - "fsl,imx8mq-mipi-dphy"
-- clocks: Must contain an entry for each entry in clock-names.
-- clock-names: Must contain the following entries:
-  - "phy_ref": phandle and specifier referring to the DPHY ref clock
-- reg: the register range of the PHY controller
-- #phy-cells: number of cells in PHY, as defined in
-  Documentation/devicetree/bindings/phy/phy-bindings.txt
-  this must be <0>
-
-Optional properties:
-- power-domains: phandle to power domain
-
-Example:
-	dphy: dphy@30a0030 {
-		compatible = "fsl,imx8mq-mipi-dphy";
-		clocks = <&clk IMX8MQ_CLK_DSI_PHY_REF>;
-		clock-names = "phy_ref";
-		reg = <0x30a00300 0x100>;
-		power-domains = <&pd_mipi0>;
-		#phy-cells = <0>;
-        };
diff --git a/Documentation/devicetree/bindings/phy/mixel,mipi-dsi-phy.yaml b/Documentation/devicetree/bindings/phy/mixel,mipi-dsi-phy.yaml
new file mode 100644
index 00000000..c34f2e6
--- /dev/null
+++ b/Documentation/devicetree/bindings/phy/mixel,mipi-dsi-phy.yaml
@@ -0,0 +1,72 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/phy/mixel,mipi-dsi-phy.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Mixel DSI PHY for i.MX8
+
+maintainers:
+  - Guido Günther <agx@sigxcpu.org>
+
+description: |
+  The Mixel MIPI-DSI PHY IP block is e.g. found on i.MX8 platforms (along the
+  MIPI-DSI IP from Northwest Logic). It represents the physical layer for the
+  electrical signals for DSI.
+
+properties:
+  compatible:
+    enum:
+      - fsl,imx8mq-mipi-dphy
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    const: phy_ref
+
+  assigned-clocks:
+    maxItems: 1
+
+  assigned-clock-parents:
+    maxItems: 1
+
+  assigned-clock-rates:
+    maxItems: 1
+
+  "#phy-cells":
+    const: 0
+
+  power-domains:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - assigned-clocks
+  - assigned-clock-parents
+  - assigned-clock-rates
+  - "#phy-cells"
+  - power-domains
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/imx8mq-clock.h>
+    dphy: dphy@30a0030 {
+        compatible = "fsl,imx8mq-mipi-dphy";
+        reg = <0x30a00300 0x100>;
+        clocks = <&clk IMX8MQ_CLK_DSI_PHY_REF>;
+        clock-names = "phy_ref";
+        assigned-clocks = <&clk IMX8MQ_CLK_DSI_PHY_REF>;
+        assigned-clock-parents = <&clk IMX8MQ_VIDEO_PLL1_OUT>;
+        assigned-clock-rates = <24000000>;
+        #phy-cells = <0>;
+        power-domains = <&pgc_mipi>;
+    };
-- 
2.7.4

[PATCH v5 4/5] dt-bindings: phy: mixel: mipi-dsi-phy: Add Mixel combo PHY support for i.MX8qxp

[Liu Ying]

Add support for Mixel MIPI DPHY + LVDS PHY combo IP
as found on Freescale i.MX8qxp SoC.

Cc: Guido Günther <agx@sigxcpu.org>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: NXP Linux Team <linux-imx@nxp.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Guido Günther <agx@sigxcpu.org>
Signed-off-by: Liu Ying <victor.liu@nxp.com>
---
v4->v5:
* No change.

v3->v4:
* Add Rob's and Guido's R-b tags.

v2->v3:
* No change.

v1->v2:
* Add the binding for i.MX8qxp Mixel combo PHY based on the converted binding.
  (Guido)

 .../bindings/phy/mixel,mipi-dsi-phy.yaml           | 41 ++++++++++++++++++++--
 1 file changed, 38 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/phy/mixel,mipi-dsi-phy.yaml b/Documentation/devicetree/bindings/phy/mixel,mipi-dsi-phy.yaml
index c34f2e6..786cfd7 100644
--- a/Documentation/devicetree/bindings/phy/mixel,mipi-dsi-phy.yaml
+++ b/Documentation/devicetree/bindings/phy/mixel,mipi-dsi-phy.yaml
@@ -14,10 +14,14 @@ description: |
   MIPI-DSI IP from Northwest Logic). It represents the physical layer for the
   electrical signals for DSI.
 
+  The Mixel PHY IP block found on i.MX8qxp is a combo PHY that can work
+  in either MIPI-DSI PHY mode or LVDS PHY mode.
+
 properties:
   compatible:
     enum:
       - fsl,imx8mq-mipi-dphy
+      - fsl,imx8qxp-mipi-dphy
 
   reg:
     maxItems: 1
@@ -40,6 +44,11 @@ properties:
   "#phy-cells":
     const: 0
 
+  fsl,syscon:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description: |
+      A phandle which points to Control and Status Registers(CSR) module.
+
   power-domains:
     maxItems: 1
 
@@ -48,12 +57,38 @@ required:
   - reg
   - clocks
   - clock-names
-  - assigned-clocks
-  - assigned-clock-parents
-  - assigned-clock-rates
   - "#phy-cells"
   - power-domains
 
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: fsl,imx8mq-mipi-dphy
+    then:
+      properties:
+        fsl,syscon: false
+
+      required:
+        - assigned-clocks
+        - assigned-clock-parents
+        - assigned-clock-rates
+
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: fsl,imx8qxp-mipi-dphy
+    then:
+      properties:
+        assigned-clocks: false
+        assigned-clock-parents: false
+        assigned-clock-rates: false
+
+      required:
+        - fsl,syscon
+
 additionalProperties: false
 
 examples:
-- 
2.7.4

[PATCH v5 5/5] phy: freescale: phy-fsl-imx8-mipi-dphy: Add i.MX8qxp LVDS PHY mode support

[Liu Ying]

i.MX8qxp SoC embeds a Mixel MIPI DPHY + LVDS PHY combo which supports
either a MIPI DSI display or a LVDS display.  The PHY mode is controlled
by SCU firmware and the driver would call a SCU firmware function to
configure the PHY mode.  The single LVDS PHY has 4 data lanes to support
a LVDS display.  Also, with a master LVDS PHY and a slave LVDS PHY, they
may work together to support a LVDS display with 8 data lanes(usually, dual
LVDS link display).  Note that this patch supports the LVDS PHY mode only
for the i.MX8qxp Mixel combo PHY, i.e., the MIPI DPHY mode is yet to be
supported, so for now error would be returned from ->set_mode() if MIPI
DPHY mode is passed over to it for the combo PHY.

Cc: Guido Günther <agx@sigxcpu.org>
Cc: Robert Chiras <robert.chiras@nxp.com>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: NXP Linux Team <linux-imx@nxp.com>
Reviewed-by: Guido Günther <agx@sigxcpu.org>
Signed-off-by: Liu Ying <victor.liu@nxp.com>
---
v4->v5:
* No change.

v3->v4:
* Add Guido's R-b tag.

v2->v3:
* Improve readability of mixel_dphy_set_mode(). (Guido)

v1->v2:
* Print invalid PHY mode in dmesg. (Guido)

 drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c | 269 ++++++++++++++++++++++++-
 1 file changed, 258 insertions(+), 11 deletions(-)

diff --git a/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c b/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
index a95572b..af1ecda 100644
--- a/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
+++ b/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
@@ -4,17 +4,31 @@
  * Copyright 2019 Purism SPC
  */
 
+#include <linux/bitfield.h>
 #include <linux/clk.h>
 #include <linux/clk-provider.h>
 #include <linux/delay.h>
+#include <linux/firmware/imx/ipc.h>
+#include <linux/firmware/imx/svc/misc.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_platform.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
+#include <dt-bindings/firmware/imx/rsrc.h>
+
+/* Control and Status Registers(CSR) */
+#define PHY_CTRL			0x00
+#define  CCM_MASK			GENMASK(7, 5)
+#define  CCM(n)				FIELD_PREP(CCM_MASK, (n))
+#define  CA_MASK			GENMASK(4, 2)
+#define  CA(n)				FIELD_PREP(CA_MASK, (n))
+#define  RFB				BIT(1)
+#define  LVDS_EN			BIT(0)
 
 /* DPHY registers */
 #define DPHY_PD_DPHY			0x00
@@ -55,8 +69,15 @@
 #define PWR_ON	0
 #define PWR_OFF	1
 
+#define MIN_VCO_FREQ 640000000
+#define MAX_VCO_FREQ 1500000000
+
+#define MIN_LVDS_REFCLK_FREQ 24000000
+#define MAX_LVDS_REFCLK_FREQ 150000000
+
 enum mixel_dphy_devtype {
 	MIXEL_IMX8MQ,
+	MIXEL_IMX8QXP,
 };
 
 struct mixel_dphy_devdata {
@@ -65,6 +86,7 @@ struct mixel_dphy_devdata {
 	u8 reg_rxlprp;
 	u8 reg_rxcdrp;
 	u8 reg_rxhs_settle;
+	bool is_combo;	/* MIPI DPHY and LVDS PHY combo */
 };
 
 static const struct mixel_dphy_devdata mixel_dphy_devdata[] = {
@@ -74,6 +96,10 @@ static const struct mixel_dphy_devdata mixel_dphy_devdata[] = {
 		.reg_rxlprp = 0x40,
 		.reg_rxcdrp = 0x44,
 		.reg_rxhs_settle = 0x48,
+		.is_combo = false,
+	},
+	[MIXEL_IMX8QXP] = {
+		.is_combo = true,
 	},
 };
 
@@ -95,8 +121,12 @@ struct mixel_dphy_cfg {
 struct mixel_dphy_priv {
 	struct mixel_dphy_cfg cfg;
 	struct regmap *regmap;
+	struct regmap *lvds_regmap;
 	struct clk *phy_ref_clk;
 	const struct mixel_dphy_devdata *devdata;
+	struct imx_sc_ipc *ipc_handle;
+	bool is_slave;
+	int id;
 };
 
 static const struct regmap_config mixel_dphy_regmap_config = {
@@ -317,7 +347,8 @@ static int mixel_dphy_set_pll_params(struct phy *phy)
 	return 0;
 }
 
-static int mixel_dphy_configure(struct phy *phy, union phy_configure_opts *opts)
+static int
+mixel_dphy_configure_mipi_dphy(struct phy *phy, union phy_configure_opts *opts)
 {
 	struct mixel_dphy_priv *priv = phy_get_drvdata(phy);
 	struct mixel_dphy_cfg cfg = { 0 };
@@ -345,15 +376,121 @@ static int mixel_dphy_configure(struct phy *phy, union phy_configure_opts *opts)
 	return 0;
 }
 
+static int
+mixel_dphy_configure_lvds_phy(struct phy *phy, union phy_configure_opts *opts)
+{
+	struct mixel_dphy_priv *priv = phy_get_drvdata(phy);
+	struct phy_configure_opts_lvds *lvds_opts = &opts->lvds;
+	unsigned long data_rate;
+	unsigned long fvco;
+	u32 rsc;
+	u32 co;
+	int ret;
+
+	priv->is_slave = lvds_opts->is_slave;
+
+	/* LVDS interface pins */
+	regmap_write(priv->lvds_regmap, PHY_CTRL, CCM(0x5) | CA(0x4) | RFB);
+
+	/* enable MODE8 only for slave LVDS PHY */
+	rsc = priv->id ? IMX_SC_R_MIPI_1 : IMX_SC_R_MIPI_0;
+	ret = imx_sc_misc_set_control(priv->ipc_handle, rsc, IMX_SC_C_DUAL_MODE,
+				      lvds_opts->is_slave);
+	if (ret) {
+		dev_err(&phy->dev, "Failed to configure MODE8: %d\n", ret);
+		return ret;
+	}
+
+	/*
+	 * Choose an appropriate divider ratio to meet the requirement of
+	 * PLL VCO frequency range.
+	 *
+	 *  -----  640MHz ~ 1500MHz   ------------      ---------------
+	 * | VCO | ----------------> | CO divider | -> | LVDS data rate|
+	 *  -----       FVCO          ------------      ---------------
+	 *                            1/2/4/8 div     7 * differential_clk_rate
+	 */
+	data_rate = 7 * lvds_opts->differential_clk_rate;
+	for (co = 1; co <= 8; co *= 2) {
+		fvco = data_rate * co;
+
+		if (fvco >= MIN_VCO_FREQ)
+			break;
+	}
+
+	if (fvco < MIN_VCO_FREQ || fvco > MAX_VCO_FREQ) {
+		dev_err(&phy->dev, "VCO frequency %lu is out of range\n", fvco);
+		return -ERANGE;
+	}
+
+	/*
+	 * CO is configurable, while CN and CM are not,
+	 * as fixed ratios 1 and 7 are applied respectively.
+	 */
+	phy_write(phy, __ffs(co), DPHY_CO);
+
+	/* set reference clock rate */
+	clk_set_rate(priv->phy_ref_clk, lvds_opts->differential_clk_rate);
+
+	return ret;
+}
+
+static int mixel_dphy_configure(struct phy *phy, union phy_configure_opts *opts)
+{
+	if (phy->attrs.mode == PHY_MODE_MIPI_DPHY)
+		return mixel_dphy_configure_mipi_dphy(phy, opts);
+	else if (phy->attrs.mode == PHY_MODE_LVDS)
+		return mixel_dphy_configure_lvds_phy(phy, opts);
+
+	dev_err(&phy->dev,
+		"Failed to configure PHY with invalid PHY mode: %d\n",
+							phy->attrs.mode);
+	return -EINVAL;
+}
+
+static int
+mixel_dphy_validate_lvds_phy(struct phy *phy, union phy_configure_opts *opts)
+{
+	struct phy_configure_opts_lvds *lvds_cfg = &opts->lvds;
+
+	if (lvds_cfg->bits_per_lane_and_dclk_cycle != 7) {
+		dev_err(&phy->dev, "Invalid bits per LVDS data lane: %u\n",
+					lvds_cfg->bits_per_lane_and_dclk_cycle);
+		return -EINVAL;
+	}
+
+	if (lvds_cfg->lanes != 4) {
+		dev_err(&phy->dev, "Invalid LVDS data lanes: %u\n",
+						lvds_cfg->lanes);
+		return -EINVAL;
+	}
+
+	if (lvds_cfg->differential_clk_rate < MIN_LVDS_REFCLK_FREQ ||
+	    lvds_cfg->differential_clk_rate > MAX_LVDS_REFCLK_FREQ) {
+		dev_err(&phy->dev,
+			"Invalid LVDS differential clock rate: %lu\n",
+					lvds_cfg->differential_clk_rate);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static int mixel_dphy_validate(struct phy *phy, enum phy_mode mode, int submode,
 			       union phy_configure_opts *opts)
 {
-	struct mixel_dphy_cfg cfg = { 0 };
+	if (mode == PHY_MODE_MIPI_DPHY) {
+		struct mixel_dphy_cfg mipi_dphy_cfg = { 0 };
 
-	if (mode != PHY_MODE_MIPI_DPHY)
-		return -EINVAL;
+		return mixel_dphy_config_from_opts(phy, &opts->mipi_dphy,
+							&mipi_dphy_cfg);
+	} else if (mode == PHY_MODE_LVDS) {
+		return mixel_dphy_validate_lvds_phy(phy, opts);
+	}
 
-	return mixel_dphy_config_from_opts(phy, &opts->mipi_dphy, &cfg);
+	dev_err(&phy->dev,
+		"Failed to validate PHY with invalid PHY mode: %d\n", mode);
+	return -EINVAL;
 }
 
 static int mixel_dphy_init(struct phy *phy)
@@ -373,27 +510,75 @@ static int mixel_dphy_exit(struct phy *phy)
 	return 0;
 }
 
-static int mixel_dphy_power_on(struct phy *phy)
+static int mixel_dphy_power_on_mipi_dphy(struct phy *phy)
 {
 	struct mixel_dphy_priv *priv = phy_get_drvdata(phy);
 	u32 locked;
 	int ret;
 
-	ret = clk_prepare_enable(priv->phy_ref_clk);
-	if (ret < 0)
-		return ret;
-
 	phy_write(phy, PWR_ON, DPHY_PD_PLL);
 	ret = regmap_read_poll_timeout(priv->regmap, DPHY_LOCK, locked,
 				       locked, PLL_LOCK_SLEEP,
 				       PLL_LOCK_TIMEOUT);
 	if (ret < 0) {
 		dev_err(&phy->dev, "Could not get DPHY lock (%d)!\n", ret);
-		goto clock_disable;
+		return ret;
 	}
 	phy_write(phy, PWR_ON, DPHY_PD_DPHY);
 
 	return 0;
+}
+
+static int mixel_dphy_power_on_lvds_phy(struct phy *phy)
+{
+	struct mixel_dphy_priv *priv = phy_get_drvdata(phy);
+	u32 locked;
+	int ret;
+
+	regmap_update_bits(priv->lvds_regmap, PHY_CTRL, LVDS_EN, LVDS_EN);
+
+	phy_write(phy, PWR_ON, DPHY_PD_DPHY);
+	phy_write(phy, PWR_ON, DPHY_PD_PLL);
+
+	/* do not wait for slave LVDS PHY being locked */
+	if (priv->is_slave)
+		return 0;
+
+	ret = regmap_read_poll_timeout(priv->regmap, DPHY_LOCK, locked,
+				       locked, PLL_LOCK_SLEEP,
+				       PLL_LOCK_TIMEOUT);
+	if (ret < 0) {
+		dev_err(&phy->dev, "Could not get LVDS PHY lock (%d)!\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int mixel_dphy_power_on(struct phy *phy)
+{
+	struct mixel_dphy_priv *priv = phy_get_drvdata(phy);
+	int ret;
+
+	ret = clk_prepare_enable(priv->phy_ref_clk);
+	if (ret < 0)
+		return ret;
+
+	if (phy->attrs.mode == PHY_MODE_MIPI_DPHY) {
+		ret = mixel_dphy_power_on_mipi_dphy(phy);
+	} else if (phy->attrs.mode == PHY_MODE_LVDS) {
+		ret = mixel_dphy_power_on_lvds_phy(phy);
+	} else {
+		dev_err(&phy->dev,
+			"Failed to power on PHY with invalid PHY mode: %d\n",
+							phy->attrs.mode);
+		ret = -EINVAL;
+	}
+
+	if (ret)
+		goto clock_disable;
+
+	return 0;
 clock_disable:
 	clk_disable_unprepare(priv->phy_ref_clk);
 	return ret;
@@ -406,16 +591,51 @@ static int mixel_dphy_power_off(struct phy *phy)
 	phy_write(phy, PWR_OFF, DPHY_PD_PLL);
 	phy_write(phy, PWR_OFF, DPHY_PD_DPHY);
 
+	if (phy->attrs.mode == PHY_MODE_LVDS)
+		regmap_update_bits(priv->lvds_regmap, PHY_CTRL, LVDS_EN, 0);
+
 	clk_disable_unprepare(priv->phy_ref_clk);
 
 	return 0;
 }
 
+static int mixel_dphy_set_mode(struct phy *phy, enum phy_mode mode, int submode)
+{
+	struct mixel_dphy_priv *priv = phy_get_drvdata(phy);
+	int ret;
+
+	if (priv->devdata->is_combo && mode != PHY_MODE_LVDS) {
+		dev_err(&phy->dev, "Failed to set PHY mode for combo PHY\n");
+		return -EINVAL;
+	}
+
+	if (!priv->devdata->is_combo && mode != PHY_MODE_MIPI_DPHY) {
+		dev_err(&phy->dev, "Failed to set PHY mode to MIPI DPHY\n");
+		return -EINVAL;
+	}
+
+	if (priv->devdata->is_combo) {
+		u32 rsc = priv->id ? IMX_SC_R_MIPI_1 : IMX_SC_R_MIPI_0;
+
+		ret = imx_sc_misc_set_control(priv->ipc_handle,
+					      rsc, IMX_SC_C_MODE,
+					      mode == PHY_MODE_LVDS);
+		if (ret) {
+			dev_err(&phy->dev,
+				"Failed to set PHY mode via SCU ipc: %d\n", ret);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
 static const struct phy_ops mixel_dphy_phy_ops = {
 	.init = mixel_dphy_init,
 	.exit = mixel_dphy_exit,
 	.power_on = mixel_dphy_power_on,
 	.power_off = mixel_dphy_power_off,
+	.set_mode = mixel_dphy_set_mode,
 	.configure = mixel_dphy_configure,
 	.validate = mixel_dphy_validate,
 	.owner = THIS_MODULE,
@@ -424,6 +644,8 @@ static const struct phy_ops mixel_dphy_phy_ops = {
 static const struct of_device_id mixel_dphy_of_match[] = {
 	{ .compatible = "fsl,imx8mq-mipi-dphy",
 	  .data = &mixel_dphy_devdata[MIXEL_IMX8MQ] },
+	{ .compatible = "fsl,imx8qxp-mipi-dphy",
+	  .data = &mixel_dphy_devdata[MIXEL_IMX8QXP] },
 	{ /* sentinel */ },
 };
 MODULE_DEVICE_TABLE(of, mixel_dphy_of_match);
@@ -436,6 +658,7 @@ static int mixel_dphy_probe(struct platform_device *pdev)
 	struct mixel_dphy_priv *priv;
 	struct phy *phy;
 	void __iomem *base;
+	int ret;
 
 	if (!np)
 		return -ENODEV;
@@ -467,6 +690,30 @@ static int mixel_dphy_probe(struct platform_device *pdev)
 	dev_dbg(dev, "phy_ref clock rate: %lu\n",
 		clk_get_rate(priv->phy_ref_clk));
 
+	if (priv->devdata->is_combo) {
+		priv->lvds_regmap =
+			syscon_regmap_lookup_by_phandle(np, "fsl,syscon");
+		if (IS_ERR(priv->lvds_regmap)) {
+			ret = PTR_ERR(priv->lvds_regmap);
+			dev_err_probe(dev, ret, "Failed to get LVDS regmap\n");
+			return ret;
+		}
+
+		priv->id = of_alias_get_id(np, "mipi_dphy");
+		if (priv->id < 0) {
+			dev_err(dev, "Failed to get phy node alias id: %d\n",
+								 priv->id);
+			return priv->id;
+		}
+
+		ret = imx_scu_get_handle(&priv->ipc_handle);
+		if (ret) {
+			dev_err_probe(dev, ret,
+				      "Failed to get SCU ipc handle\n");
+			return ret;
+		}
+	}
+
 	dev_set_drvdata(dev, priv);
 
 	phy = devm_phy_create(dev, np, &mixel_dphy_phy_ops);
-- 
2.7.4

Re: [PATCH v5 2/5] phy: Add LVDS configuration options

[Kishon Vijay Abraham I]

Hi,

On 25/03/21 2:30 pm, Liu Ying wrote:
> This patch allows LVDS PHYs to be configured through
> the generic functions and through a custom structure
> added to the generic union.
> 
> The parameters added here are based on common LVDS PHY
> implementation practices.  The set of parameters
> should cover all potential users.
> 
> Cc: Kishon Vijay Abraham I <kishon@ti.com>
> Cc: Vinod Koul <vkoul@kernel.org>
> Cc: NXP Linux Team <linux-imx@nxp.com>
> Signed-off-by: Liu Ying <victor.liu@nxp.com>
> ---
> v4->v5:
> * Align kernel-doc style to include/linux/phy/phy.h. (Vinod)
> * Trivial tweaks.
> * Drop Robert's R-b tag.
> 
> v3->v4:
> * Add Robert's R-b tag.
> 
> v2->v3:
> * No change.
> 
> v1->v2:
> * No change.
> 
>  include/linux/phy/phy-lvds.h | 32 ++++++++++++++++++++++++++++++++
>  include/linux/phy/phy.h      |  4 ++++
>  2 files changed, 36 insertions(+)
>  create mode 100644 include/linux/phy/phy-lvds.h
> 
> diff --git a/include/linux/phy/phy-lvds.h b/include/linux/phy/phy-lvds.h
> new file mode 100644
> index 00000000..7a2f474
> --- /dev/null
> +++ b/include/linux/phy/phy-lvds.h
> @@ -0,0 +1,32 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright 2020 NXP
> + */
> +
> +#ifndef __PHY_LVDS_H_
> +#define __PHY_LVDS_H_
> +
> +/**
> + * struct phy_configure_opts_lvds - LVDS configuration set
> + * @bits_per_lane_and_dclk_cycle:	Number of bits per data lane and
> + *					differential clock cycle.

phy_set_bus_width() instead?
> + * @differential_clk_rate:		Clock rate, in Hertz, of the LVDS
> + *					differential clock.

Please use clk API's to get rate.
> + * @lanes:				Number of active, consecutive,
> + *					data lanes, starting from lane 0,
> + *					used for the transmissions.
> + * @is_slave:				Boolean, true if the phy is a slave
> + *					which works together with a master
> + *					phy to support dual link transmission,
> + *					otherwise a regular phy or a master phy.

For parameters that are known at design time, it doesn't have to be
passed from consumer driver. So all these parameters do they really have
to be passed at runtime?

Thanks
Kishon
> + *
> + * This structure is used to represent the configuration state of a LVDS phy.
> + */
> +struct phy_configure_opts_lvds {
> +	unsigned int	bits_per_lane_and_dclk_cycle;
> +	unsigned long	differential_clk_rate;
> +	unsigned int	lanes;
> +	bool		is_slave;
> +};
> +
> +#endif /* __PHY_LVDS_H_ */
> diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
> index e435bdb..d450b44 100644
> --- a/include/linux/phy/phy.h
> +++ b/include/linux/phy/phy.h
> @@ -17,6 +17,7 @@
>  #include <linux/regulator/consumer.h>
>  
>  #include <linux/phy/phy-dp.h>
> +#include <linux/phy/phy-lvds.h>
>  #include <linux/phy/phy-mipi-dphy.h>
>  
>  struct phy;
> @@ -51,10 +52,13 @@ enum phy_mode {
>   *		the MIPI_DPHY phy mode.
>   * @dp:		Configuration set applicable for phys supporting
>   *		the DisplayPort protocol.
> + * @lvds:	Configuration set applicable for phys supporting
> + *		the LVDS phy mode.
>   */
>  union phy_configure_opts {
>  	struct phy_configure_opts_mipi_dphy	mipi_dphy;
>  	struct phy_configure_opts_dp		dp;
> +	struct phy_configure_opts_lvds		lvds;
>  };
>  
>  /**
> 

Re: [PATCH v5 2/5] phy: Add LVDS configuration options

[Liu Ying]

Hi Kishon,

First of all, thanks for your review.

On Wed, 2021-03-31 at 19:02 +0530, Kishon Vijay Abraham I wrote:
> Hi,
> 
> On 25/03/21 2:30 pm, Liu Ying wrote:
> > This patch allows LVDS PHYs to be configured through
> > the generic functions and through a custom structure
> > added to the generic union.
> > 
> > The parameters added here are based on common LVDS PHY
> > implementation practices.  The set of parameters
> > should cover all potential users.
> > 
> > Cc: Kishon Vijay Abraham I <kishon@ti.com>
> > Cc: Vinod Koul <vkoul@kernel.org>
> > Cc: NXP Linux Team <linux-imx@nxp.com>
> > Signed-off-by: Liu Ying <victor.liu@nxp.com>
> > ---
> > v4->v5:
> > * Align kernel-doc style to include/linux/phy/phy.h. (Vinod)
> > * Trivial tweaks.
> > * Drop Robert's R-b tag.
> > 
> > v3->v4:
> > * Add Robert's R-b tag.
> > 
> > v2->v3:
> > * No change.
> > 
> > v1->v2:
> > * No change.
> > 
> >  include/linux/phy/phy-lvds.h | 32 ++++++++++++++++++++++++++++++++
> >  include/linux/phy/phy.h      |  4 ++++
> >  2 files changed, 36 insertions(+)
> >  create mode 100644 include/linux/phy/phy-lvds.h
> > 
> > diff --git a/include/linux/phy/phy-lvds.h b/include/linux/phy/phy-lvds.h
> > new file mode 100644
> > index 00000000..7a2f474
> > --- /dev/null
> > +++ b/include/linux/phy/phy-lvds.h
> > @@ -0,0 +1,32 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +/*
> > + * Copyright 2020 NXP
> > + */
> > +
> > +#ifndef __PHY_LVDS_H_
> > +#define __PHY_LVDS_H_
> > +
> > +/**
> > + * struct phy_configure_opts_lvds - LVDS configuration set
> > + * @bits_per_lane_and_dclk_cycle:	Number of bits per data lane and
> > + *					differential clock cycle.
> 
> phy_set_bus_width() instead?

This member aims to configure the number of bits transmitted during a
period of time(a clock cycle). It doesn't sound like a concept of 'bus
width'?

> > + * @differential_clk_rate:		Clock rate, in Hertz, of the LVDS
> > + *					differential clock.
> 
> Please use clk API's to get rate.

I like your idea. But, this rate is likely runtime-configurable, e.g.,
a LVDS to HDMI chip is connected. It seems that there is no appropriate
driver to set the rate by calling clk_set_rate() then?

> > + * @lanes:				Number of active, consecutive,
> > + *					data lanes, starting from lane 0,
> > + *					used for the transmissions.
> > + * @is_slave:				Boolean, true if the phy is a slave
> > + *					which works together with a master
> > + *					phy to support dual link transmission,
> > + *					otherwise a regular phy or a master phy.
> 
> For parameters that are known at design time, it doesn't have to be
> passed from consumer driver. So all these parameters do they really have
> to be passed at runtime?

Yes for all, perhaps. Details below:

1) bits_per_lane_and_dclk_cycle
i.MX8qxp LVDS phy can only do 7, while i.MX8qm LVDS phy(a different IP)
can do either 7 or 10(configurable by setting a phy register).

2) differential_clk_rate
It's likely runtime-configurable, as I mentioned above.

3) lanes
The higher color depth is, the more lanes are used:
RGB666 - 3 lanes
RGB888 - 4 lanes
RGB101010 - 5 lanes

That means a phy with 5 lanes(like i.MX8qm LVDS phy) support up to the
3 types of RGB pixels.

Though the i.MX LVDS phys don't have any register to configure the
lanes to be used, it would be good to define it for phy_validate() or
other potential phys?

4) is_slave
Any i.MX8qxp LVDS phy instance can act as a regular phy or a master phy
or a slave phy. Changing mode at runtime is probably unneeded. But,
it's difficult for the phy driver to get the mode from device tree(see
drm_of_lvds_get_port_pixels_type()), I think. Export an i.MX8qxp LVDS
phy specific function to set this instead?

Regards,
Liu Ying

> 
> Thanks
> Kishon
> > + *
> > + * This structure is used to represent the configuration state of a LVDS phy.
> > + */
> > +struct phy_configure_opts_lvds {
> > +	unsigned int	bits_per_lane_and_dclk_cycle;
> > +	unsigned long	differential_clk_rate;
> > +	unsigned int	lanes;
> > +	bool		is_slave;
> > +};
> > +
> > +#endif /* __PHY_LVDS_H_ */
> > diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
> > index e435bdb..d450b44 100644
> > --- a/include/linux/phy/phy.h
> > +++ b/include/linux/phy/phy.h
> > @@ -17,6 +17,7 @@
> >  #include <linux/regulator/consumer.h>
> >  
> >  #include <linux/phy/phy-dp.h>
> > +#include <linux/phy/phy-lvds.h>
> >  #include <linux/phy/phy-mipi-dphy.h>
> >  
> >  struct phy;
> > @@ -51,10 +52,13 @@ enum phy_mode {
> >   *		the MIPI_DPHY phy mode.
> >   * @dp:		Configuration set applicable for phys supporting
> >   *		the DisplayPort protocol.
> > + * @lvds:	Configuration set applicable for phys supporting
> > + *		the LVDS phy mode.
> >   */
> >  union phy_configure_opts {
> >  	struct phy_configure_opts_mipi_dphy	mipi_dphy;
> >  	struct phy_configure_opts_dp		dp;
> > +	struct phy_configure_opts_lvds		lvds;
> >  };
> >  
> >  /**
> > 

Re: [PATCH v5 2/5] phy: Add LVDS configuration options

[Liu Ying]

Hi Kishon, Vinod,

Any follow-up comments/suggestions based on my previous reply?
Or, perhaps, just keep the patch as-is to support the generic lvds phy
configuration structure?

Thanks,
Liu Ying

On Thu, 2021-04-01 at 16:36 +0800, Liu Ying wrote:
> Hi Kishon,
> 
> First of all, thanks for your review.
> 
> On Wed, 2021-03-31 at 19:02 +0530, Kishon Vijay Abraham I wrote:
> > Hi,
> > 
> > On 25/03/21 2:30 pm, Liu Ying wrote:
> > > This patch allows LVDS PHYs to be configured through
> > > the generic functions and through a custom structure
> > > added to the generic union.
> > > 
> > > The parameters added here are based on common LVDS PHY
> > > implementation practices.  The set of parameters
> > > should cover all potential users.
> > > 
> > > Cc: Kishon Vijay Abraham I <kishon@ti.com>
> > > Cc: Vinod Koul <vkoul@kernel.org>
> > > Cc: NXP Linux Team <linux-imx@nxp.com>
> > > Signed-off-by: Liu Ying <victor.liu@nxp.com>
> > > ---
> > > v4->v5:
> > > * Align kernel-doc style to include/linux/phy/phy.h. (Vinod)
> > > * Trivial tweaks.
> > > * Drop Robert's R-b tag.
> > > 
> > > v3->v4:
> > > * Add Robert's R-b tag.
> > > 
> > > v2->v3:
> > > * No change.
> > > 
> > > v1->v2:
> > > * No change.
> > > 
> > >  include/linux/phy/phy-lvds.h | 32 ++++++++++++++++++++++++++++++++
> > >  include/linux/phy/phy.h      |  4 ++++
> > >  2 files changed, 36 insertions(+)
> > >  create mode 100644 include/linux/phy/phy-lvds.h
> > > 
> > > diff --git a/include/linux/phy/phy-lvds.h b/include/linux/phy/phy-lvds.h
> > > new file mode 100644
> > > index 00000000..7a2f474
> > > --- /dev/null
> > > +++ b/include/linux/phy/phy-lvds.h
> > > @@ -0,0 +1,32 @@
> > > +/* SPDX-License-Identifier: GPL-2.0 */
> > > +/*
> > > + * Copyright 2020 NXP
> > > + */
> > > +
> > > +#ifndef __PHY_LVDS_H_
> > > +#define __PHY_LVDS_H_
> > > +
> > > +/**
> > > + * struct phy_configure_opts_lvds - LVDS configuration set
> > > + * @bits_per_lane_and_dclk_cycle:	Number of bits per data lane and
> > > + *					differential clock cycle.
> > 
> > phy_set_bus_width() instead?
> 
> This member aims to configure the number of bits transmitted during a
> period of time(a clock cycle). It doesn't sound like a concept of 'bus
> width'?
> 
> > > + * @differential_clk_rate:		Clock rate, in Hertz, of the LVDS
> > > + *					differential clock.
> > 
> > Please use clk API's to get rate.
> 
> I like your idea. But, this rate is likely runtime-configurable, e.g.,
> a LVDS to HDMI chip is connected. It seems that there is no appropriate
> driver to set the rate by calling clk_set_rate() then?
> 
> > > + * @lanes:				Number of active, consecutive,
> > > + *					data lanes, starting from lane 0,
> > > + *					used for the transmissions.
> > > + * @is_slave:				Boolean, true if the phy is a slave
> > > + *					which works together with a master
> > > + *					phy to support dual link transmission,
> > > + *					otherwise a regular phy or a master phy.
> > 
> > For parameters that are known at design time, it doesn't have to be
> > passed from consumer driver. So all these parameters do they really have
> > to be passed at runtime?
> 
> Yes for all, perhaps. Details below:
> 
> 1) bits_per_lane_and_dclk_cycle
> i.MX8qxp LVDS phy can only do 7, while i.MX8qm LVDS phy(a different IP)
> can do either 7 or 10(configurable by setting a phy register).
> 
> 2) differential_clk_rate
> It's likely runtime-configurable, as I mentioned above.
> 
> 3) lanes
> The higher color depth is, the more lanes are used:
> RGB666 - 3 lanes
> RGB888 - 4 lanes
> RGB101010 - 5 lanes
> 
> That means a phy with 5 lanes(like i.MX8qm LVDS phy) support up to the
> 3 types of RGB pixels.
> 
> Though the i.MX LVDS phys don't have any register to configure the
> lanes to be used, it would be good to define it for phy_validate() or
> other potential phys?
> 
> 4) is_slave
> Any i.MX8qxp LVDS phy instance can act as a regular phy or a master phy
> or a slave phy. Changing mode at runtime is probably unneeded. But,
> it's difficult for the phy driver to get the mode from device tree(see
> drm_of_lvds_get_port_pixels_type()), I think. Export an i.MX8qxp LVDS
> phy specific function to set this instead?
> 
> Regards,
> Liu Ying
> 
> > Thanks
> > Kishon
> > > + *
> > > + * This structure is used to represent the configuration state of a LVDS phy.
> > > + */
> > > +struct phy_configure_opts_lvds {
> > > +	unsigned int	bits_per_lane_and_dclk_cycle;
> > > +	unsigned long	differential_clk_rate;
> > > +	unsigned int	lanes;
> > > +	bool		is_slave;
> > > +};
> > > +
> > > +#endif /* __PHY_LVDS_H_ */
> > > diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
> > > index e435bdb..d450b44 100644
> > > --- a/include/linux/phy/phy.h
> > > +++ b/include/linux/phy/phy.h
> > > @@ -17,6 +17,7 @@
> > >  #include <linux/regulator/consumer.h>
> > >  
> > >  #include <linux/phy/phy-dp.h>
> > > +#include <linux/phy/phy-lvds.h>
> > >  #include <linux/phy/phy-mipi-dphy.h>
> > >  
> > >  struct phy;
> > > @@ -51,10 +52,13 @@ enum phy_mode {
> > >   *		the MIPI_DPHY phy mode.
> > >   * @dp:		Configuration set applicable for phys supporting
> > >   *		the DisplayPort protocol.
> > > + * @lvds:	Configuration set applicable for phys supporting
> > > + *		the LVDS phy mode.
> > >   */
> > >  union phy_configure_opts {
> > >  	struct phy_configure_opts_mipi_dphy	mipi_dphy;
> > >  	struct phy_configure_opts_dp		dp;
> > > +	struct phy_configure_opts_lvds		lvds;
> > >  };
> > >  
> > >  /**
> > > 

Re: [PATCH v5 2/5] phy: Add LVDS configuration options

[Liu Ying]

Hi Kishon, Vinod,

On Thu, 2021-06-10 at 17:38 +0800, Liu Ying wrote:
> Hi Kishon, Vinod,
> 
> Any follow-up comments/suggestions based on my previous reply?
> Or, perhaps, just keep the patch as-is to support the generic lvds
> phy
> configuration structure?

Ping... Any follow-up comments/suggestions please?

This series is flying for more than one year and is blocking the series
of adding DRM bridge drivers for the LVDS display pipeline on i.MX8qxp
SoC.

IMHO, the generic lvds phy configuration structure is useful to custom
drivers.  Shall we keep the patch as-is?

I may rebase this series as patch 1/1 for nwl-dsi driver needs to keep
updated with the latest nwl-dsi driver.

Two more comments below...

> 
> Thanks,
> Liu Ying
> 
> On Thu, 2021-04-01 at 16:36 +0800, Liu Ying wrote:
> > Hi Kishon,
> > 
> > First of all, thanks for your review.
> > 
> > On Wed, 2021-03-31 at 19:02 +0530, Kishon Vijay Abraham I wrote:
> > > Hi,
> > > 
> > > On 25/03/21 2:30 pm, Liu Ying wrote:
> > > > This patch allows LVDS PHYs to be configured through
> > > > the generic functions and through a custom structure
> > > > added to the generic union.
> > > > 
> > > > The parameters added here are based on common LVDS PHY
> > > > implementation practices.  The set of parameters
> > > > should cover all potential users.
> > > > 
> > > > Cc: Kishon Vijay Abraham I <kishon@ti.com>
> > > > Cc: Vinod Koul <vkoul@kernel.org>
> > > > Cc: NXP Linux Team <linux-imx@nxp.com>
> > > > Signed-off-by: Liu Ying <victor.liu@nxp.com>
> > > > ---
> > > > v4->v5:
> > > > * Align kernel-doc style to include/linux/phy/phy.h. (Vinod)
> > > > * Trivial tweaks.
> > > > * Drop Robert's R-b tag.
> > > > 
> > > > v3->v4:
> > > > * Add Robert's R-b tag.
> > > > 
> > > > v2->v3:
> > > > * No change.
> > > > 
> > > > v1->v2:
> > > > * No change.
> > > > 
> > > >  include/linux/phy/phy-lvds.h | 32
> > > > ++++++++++++++++++++++++++++++++
> > > >  include/linux/phy/phy.h      |  4 ++++
> > > >  2 files changed, 36 insertions(+)
> > > >  create mode 100644 include/linux/phy/phy-lvds.h
> > > > 
> > > > diff --git a/include/linux/phy/phy-lvds.h
> > > > b/include/linux/phy/phy-lvds.h
> > > > new file mode 100644
> > > > index 00000000..7a2f474
> > > > --- /dev/null
> > > > +++ b/include/linux/phy/phy-lvds.h
> > > > @@ -0,0 +1,32 @@
> > > > +/* SPDX-License-Identifier: GPL-2.0 */
> > > > +/*
> > > > + * Copyright 2020 NXP
> > > > + */
> > > > +
> > > > +#ifndef __PHY_LVDS_H_
> > > > +#define __PHY_LVDS_H_
> > > > +
> > > > +/**
> > > > + * struct phy_configure_opts_lvds - LVDS configuration set
> > > > + * @bits_per_lane_and_dclk_cycle:	Number of bits per data
> > > > lane and
> > > > + *					differential clock
> > > > cycle.
> > > 
> > > phy_set_bus_width() instead?
> > 
> > This member aims to configure the number of bits transmitted during
> > a
> > period of time(a clock cycle). It doesn't sound like a concept of
> > 'bus
> > width'?
> > 
> > > > + * @differential_clk_rate:		Clock rate, in Hertz,
> > > > of the LVDS
> > > > + *					differential clock.
> > > 
> > > Please use clk API's to get rate.
> > 
> > I like your idea. But, this rate is likely runtime-configurable,
> > e.g.,
> > a LVDS to HDMI chip is connected. It seems that there is no
> > appropriate
> > driver to set the rate by calling clk_set_rate() then?

It doesn't seem to be reasonable to use clk API's to get the rate,
since the phy should generate the clock signal(act as a clk provider).
If the phy drivers do act as a clk provider to register a clk for the
differential clk, the phy drivers still need some way to know the clk
rate. 'assigned-clock-rates' DT property cannot provide the rate
because the rate is likely runtime-configurable like I mentioned. So,
it looks like the differential_clk_rate member is the appropriate way
to provide the rate.  

> > 
> > > > + * @lanes:				Number of active,
> > > > consecutive,
> > > > + *					data lanes, starting
> > > > from lane 0,
> > > > + *					used for the
> > > > transmissions.
> > > > + * @is_slave:				Boolean, true if the
> > > > phy is a slave
> > > > + *					which works together
> > > > with a master
> > > > + *					phy to support dual
> > > > link transmission,
> > > > + *					otherwise a regular phy
> > > > or a master phy.
> > > 
> > > For parameters that are known at design time, it doesn't have to
> > > be
> > > passed from consumer driver. So all these parameters do they
> > > really have
> > > to be passed at runtime?
> > 
> > Yes for all, perhaps. Details below:
> > 
> > 1) bits_per_lane_and_dclk_cycle
> > i.MX8qxp LVDS phy can only do 7, while i.MX8qm LVDS phy(a different
> > IP)
> > can do either 7 or 10(configurable by setting a phy register).
> > 
> > 2) differential_clk_rate
> > It's likely runtime-configurable, as I mentioned above.
> > 
> > 3) lanes
> > The higher color depth is, the more lanes are used:
> > RGB666 - 3 lanes
> > RGB888 - 4 lanes
> > RGB101010 - 5 lanes
> > 
> > That means a phy with 5 lanes(like i.MX8qm LVDS phy) support up to
> > the
> > 3 types of RGB pixels.
> > 
> > Though the i.MX LVDS phys don't have any register to configure the
> > lanes to be used, it would be good to define it for phy_validate()
> > or
> > other potential phys?

Like the lanes member in struct phy_configure_opts_mipi_dphy, the lanes
member is useful for custom drivers to choose/validate lane number.

Regards,
Liu Ying

> > 
> > 4) is_slave
> > Any i.MX8qxp LVDS phy instance can act as a regular phy or a master
> > phy
> > or a slave phy. Changing mode at runtime is probably unneeded. But,
> > it's difficult for the phy driver to get the mode from device
> > tree(see
> > drm_of_lvds_get_port_pixels_type()), I think. Export an i.MX8qxp
> > LVDS
> > phy specific function to set this instead?
> > 
> > Regards,
> > Liu Ying
> > 
> > > Thanks
> > > Kishon
> > > > + *
> > > > + * This structure is used to represent the configuration state
> > > > of a LVDS phy.
> > > > + */
> > > > +struct phy_configure_opts_lvds {
> > > > +	unsigned int	bits_per_lane_and_dclk_cycle;
> > > > +	unsigned long	differential_clk_rate;
> > > > +	unsigned int	lanes;
> > > > +	bool		is_slave;
> > > > +};
> > > > +
> > > > +#endif /* __PHY_LVDS_H_ */
> > > > diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
> > > > index e435bdb..d450b44 100644
> > > > --- a/include/linux/phy/phy.h
> > > > +++ b/include/linux/phy/phy.h
> > > > @@ -17,6 +17,7 @@
> > > >  #include <linux/regulator/consumer.h>
> > > >  
> > > >  #include <linux/phy/phy-dp.h>
> > > > +#include <linux/phy/phy-lvds.h>
> > > >  #include <linux/phy/phy-mipi-dphy.h>
> > > >  
> > > >  struct phy;
> > > > @@ -51,10 +52,13 @@ enum phy_mode {
> > > >   *		the MIPI_DPHY phy mode.
> > > >   * @dp:		Configuration set applicable for phys
> > > > supporting
> > > >   *		the DisplayPort protocol.
> > > > + * @lvds:	Configuration set applicable for phys
> > > > supporting
> > > > + *		the LVDS phy mode.
> > > >   */
> > > >  union phy_configure_opts {
> > > >  	struct phy_configure_opts_mipi_dphy	mipi_dphy;
> > > >  	struct phy_configure_opts_dp		dp;
> > > > +	struct phy_configure_opts_lvds		lvds;
> > > >  };
> > > >  
> > > >  /**
> > > >