Merge branch 'net-ethernet-ti-netcp-update-and-enable-cpts-support'

Grygorii Strashko says:

====================
net: ethernet: ti: netcp: update and enable cpts support

The Keystone 2 66AK2HK/E/L 1G Ethernet Switch Subsystems contains The
Common Platform Time Sync (CPTS) module which is in general compatible with
CPTS module found on TI AM3/4/5 SoCs. So, the basic support for
Keystone 2 CPTS is available by default, but not documented and has never been
enabled inconfig files.

The Keystone 2 CPTS module supports also some additional features like time
sync reference (RFTCLK) clock selection through CPTS_RFTCLK_SEL register
(offset: x08) in CPTS module, which can modelled as multiplexer clock
(this was discussed some time ago [1]).

This series adds missed binding documentation for Keystone 2 66AK2HK/E/L
CPTS module and enables CPTS for TI Keystone 2 66AK2HK/E/L SoCs with possiblity
to select CPTS reference clock.

Patch 1: adds the CPTS binding documentation. CPTS bindings are defined in the
way that allows CPTS properties to be grouped under "cpts" sub-node.
It also defines "cpts-refclk-mux" clock for CPTS RFTCLK selection.
Patches 2-3: implement CPTS properties grouping under "cpts" sub-node with
backward compatibility support.
Patch 4: adds support for time sync reference (RFTCLK) clock selection from DT
by adding support for "cpts-refclk-mux" multiplexer clock.
Patches 5-9: DT CPTS nodes update for TI Keystone 2 66AK2HK/E/L SoCs.
Patch 10: enables CPTS for TI Keystone 2 66AK2HK/E/L SoCs.

I grouped all patches in one series for better illustration of the changes,
but in general Pateches 1-4 are netdev matarieal (first) and other patches
are platform specific.

Series can be found at:
 git@git.ti.com:~gragst/ti-linux-kernel/gragsts-ti-linux-kernel.git
branch:
 net-next-k2e-cpts-refclk

Changes in v2:
 - do reverse christmas tree in cpts_of_mux_clk_setup()
 - add ack from Richard Cochran

v1: https://lkml.org/lkml/2019/6/1/77

[1] https://www.spinics.net/lists/netdev/msg408931.html
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/keystone-netcp.txt

@@ -104,6 +104,23 @@ Required properties:
 			- 10Gb mac<->mac forced mode : 11
 ----phy-handle:	phandle to PHY device
 
+- cpts:		sub-node time synchronization (CPTS) submodule configuration
+-- clocks:	CPTS reference clock. Should point on cpts-refclk-mux clock.
+-- clock-names: should be "cpts"
+-- cpts-refclk-mux: multiplexer clock definition sub-node for CPTS reference (RFTCLK) clock
+--- #clock-cells: should be 0
+--- clocks:	list of CPTS reference (RFTCLK) clock's parents as defined in Data manual
+--- ti,mux-tbl: array of multiplexer indexes as defined in Data manual
+--- assigned-clocks: should point on cpts-refclk-mux clock
+--- assigned-clock-parents: should point on required RFTCLK clock parent to be selected
+-- cpts_clock_mult: (optional) Numerator to convert input clock ticks
+		into nanoseconds
+-- cpts_clock_shift: (optional) Denominator to convert input clock ticks into
+		nanoseconds.
+		Mult and shift will be calculated basing on CPTS
+		rftclk frequency if both cpts_clock_shift and
+		cpts_clock_mult properties are not provided.
+
 Optional properties:
 - enable-ale:	NetCP driver keeps the address learning feature in the ethernet
 		switch module disabled. This attribute is to enable the address
@@ -168,6 +185,23 @@ netcp: netcp@2000000 {
 			tx-queue = <648>;
 			tx-channel = <8>;
 
+			cpts {
+				clocks = <&cpts_refclk_mux>;
+				clock-names = "cpts";
+
+				cpts_refclk_mux: cpts-refclk-mux {
+					#clock-cells = <0>;
+					clocks = <&chipclk12>, <&chipclk13>,
+						 <&timi0>, <&timi1>,
+						 <&tsipclka>, <&tsrefclk>,
+						 <&tsipclkb>;
+					ti,mux-tbl = <0x0>, <0x1>, <0x2>,
+						<0x3>, <0x4>, <0x8>, <0xC>;
+					assigned-clocks = <&cpts_refclk_mux>;
+					assigned-clock-parents = <&chipclk12>;
+				};
+			};
+
 			interfaces {
 				gbe0: interface-0 {
 					slave-port = <0>;
@@ -219,3 +253,13 @@ netcp: netcp@2000000 {
 		};
 	};
 };
+
+CPTS board configuration - select external CPTS RFTCLK:
+
+&tsrefclk{
+	clock-frequency = <500000000>;
+};
+
+&cpts_refclk_mux {
+	assigned-clock-parents = <&tsrefclk>;
+};

drivers/net/ethernet/ti/cpts.c

@@ -5,6 +5,7 @@
  * Copyright (C) 2012 Richard Cochran <richardcochran@gmail.com>
  *
  */
+#include <linux/clk-provider.h>
 #include <linux/err.h>
 #include <linux/if.h>
 #include <linux/hrtimer.h>
@@ -532,6 +533,82 @@ static void cpts_calc_mult_shift(struct cpts *cpts)
 		 freq, cpts->cc.mult, cpts->cc.shift, (ns - NSEC_PER_SEC));
 }
 
+static int cpts_of_mux_clk_setup(struct cpts *cpts, struct device_node *node)
+{
+	struct device_node *refclk_np;
+	const char **parent_names;
+	unsigned int num_parents;
+	struct clk_hw *clk_hw;
+	int ret = -EINVAL;
+	u32 *mux_table;
+
+	refclk_np = of_get_child_by_name(node, "cpts-refclk-mux");
+	if (!refclk_np)
+		/* refclk selection supported not for all SoCs */
+		return 0;
+
+	num_parents = of_clk_get_parent_count(refclk_np);
+	if (num_parents < 1) {
+		dev_err(cpts->dev, "mux-clock %s must have parents\n",
+			refclk_np->name);
+		goto mux_fail;
+	}
+
+	parent_names = devm_kzalloc(cpts->dev, (sizeof(char *) * num_parents),
+				    GFP_KERNEL);
+
+	mux_table = devm_kzalloc(cpts->dev, sizeof(*mux_table) * num_parents,
+				 GFP_KERNEL);
+	if (!mux_table || !parent_names) {
+		ret = -ENOMEM;
+		goto mux_fail;
+	}
+
+	of_clk_parent_fill(refclk_np, parent_names, num_parents);
+
+	ret = of_property_read_variable_u32_array(refclk_np, "ti,mux-tbl",
+						  mux_table,
+						  num_parents, num_parents);
+	if (ret < 0)
+		goto mux_fail;
+
+	clk_hw = clk_hw_register_mux_table(cpts->dev, refclk_np->name,
+					   parent_names, num_parents,
+					   0,
+					   &cpts->reg->rftclk_sel, 0, 0x1F,
+					   0, mux_table, NULL);
+	if (IS_ERR(clk_hw)) {
+		ret = PTR_ERR(clk_hw);
+		goto mux_fail;
+	}
+
+	ret = devm_add_action_or_reset(cpts->dev,
+				       (void(*)(void *))clk_hw_unregister_mux,
+				       clk_hw);
+	if (ret) {
+		dev_err(cpts->dev, "add clkmux unreg action %d", ret);
+		goto mux_fail;
+	}
+
+	ret = of_clk_add_hw_provider(refclk_np, of_clk_hw_simple_get, clk_hw);
+	if (ret)
+		goto mux_fail;
+
+	ret = devm_add_action_or_reset(cpts->dev,
+				       (void(*)(void *))of_clk_del_provider,
+				       refclk_np);
+	if (ret) {
+		dev_err(cpts->dev, "add clkmux provider unreg action %d", ret);
+		goto mux_fail;
+	}
+
+	return ret;
+
+mux_fail:
+	of_node_put(refclk_np);
+	return ret;
+}
+
 static int cpts_of_parse(struct cpts *cpts, struct device_node *node)
 {
 	int ret = -EINVAL;
@@ -547,7 +624,7 @@ static int cpts_of_parse(struct cpts *cpts, struct device_node *node)
 	    (!cpts->cc.mult && cpts->cc.shift))
 		goto of_error;
 
-	return 0;
+	return cpts_of_mux_clk_setup(cpts, node);
 
 of_error:
 	dev_err(cpts->dev, "CPTS: Missing property in the DT.\n");
@@ -572,9 +649,14 @@ struct cpts *cpts_create(struct device *dev, void __iomem *regs,
 	if (ret)
 		return ERR_PTR(ret);
 
+	cpts->refclk = devm_get_clk_from_child(dev, node, "cpts");
+	if (IS_ERR(cpts->refclk))
+		/* try get clk from dev node for compatibility */
 		cpts->refclk = devm_clk_get(dev, "cpts");
+
 	if (IS_ERR(cpts->refclk)) {
-		dev_err(dev, "Failed to get cpts refclk\n");
+		dev_err(dev, "Failed to get cpts refclk %ld\n",
+			PTR_ERR(cpts->refclk));
 		return ERR_CAST(cpts->refclk);
 	}
 

drivers/net/ethernet/ti/cpts.h

@@ -24,7 +24,7 @@
 struct cpsw_cpts {
 	u32 idver;                /* Identification and version */
 	u32 control;              /* Time sync control */
-	u32 res1;
+	u32 rftclk_sel;		  /* Reference Clock Select Register */
 	u32 ts_push;              /* Time stamp event push */
 	u32 ts_load_val;          /* Time stamp load value */
 	u32 ts_load_en;           /* Time stamp load enable */

drivers/net/ethernet/ti/netcp_ethss.c

@@ -3554,7 +3554,7 @@ static int set_gbenu_ethss_priv(struct gbe_priv *gbe_dev,
 static int gbe_probe(struct netcp_device *netcp_device, struct device *dev,
 		     struct device_node *node, void **inst_priv)
 {
-	struct device_node *interfaces, *interface;
+	struct device_node *interfaces, *interface, *cpts_node;
 	struct device_node *secondary_ports;
 	struct cpsw_ale_params ale_params;
 	struct gbe_priv *gbe_dev;
@@ -3713,7 +3713,12 @@ static int gbe_probe(struct netcp_device *netcp_device, struct device *dev,
 		dev_dbg(gbe_dev->dev, "Created a gbe ale engine\n");
 	}
 
-	gbe_dev->cpts = cpts_create(gbe_dev->dev, gbe_dev->cpts_reg, node);
+	cpts_node = of_get_child_by_name(node, "cpts");
+	if (!cpts_node)
+		cpts_node = of_node_get(node);
+
+	gbe_dev->cpts = cpts_create(gbe_dev->dev, gbe_dev->cpts_reg, cpts_node);
+	of_node_put(cpts_node);
 	if (IS_ENABLED(CONFIG_TI_CPTS) && IS_ERR(gbe_dev->cpts)) {
 		ret = PTR_ERR(gbe_dev->cpts);
 		goto free_sec_ports;