staging: comedi: add interface to ni routing table information

Adds interface and associated unittests for accessing/looking-up/validating
the new ni routing table information.

Signed-off-by: Spencer E. Olson <olsonse@umich.edu>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/Kconfig

@@ -1313,5 +1313,9 @@ config COMEDI_NI_LABPC_ISADMA
 
 config COMEDI_NI_TIO
 	tristate
+	select COMEDI_NI_ROUTING
+
+config COMEDI_NI_ROUTING
+	tristate
 
 endif # COMEDI

drivers/staging/comedi/drivers/Makefile

@@ -137,6 +137,33 @@ obj-$(CONFIG_COMEDI_VMK80XX)		+= vmk80xx.o
 obj-$(CONFIG_COMEDI_MITE)		+= mite.o
 obj-$(CONFIG_COMEDI_NI_TIO)		+= ni_tio.o
 obj-$(CONFIG_COMEDI_NI_TIOCMD)		+= ni_tiocmd.o
+obj-$(CONFIG_COMEDI_NI_ROUTING)		+= ni_routing.o
+ni_routing-objs				+= ni_routes.o \
+					   ni_routing/ni_route_values.o \
+					   ni_routing/ni_route_values/ni_660x.o \
+					   ni_routing/ni_route_values/ni_eseries.o \
+					   ni_routing/ni_route_values/ni_mseries.o \
+					   ni_routing/ni_device_routes.o \
+					   ni_routing/ni_device_routes/pxi-6030e.o \
+					   ni_routing/ni_device_routes/pci-6070e.o \
+					   ni_routing/ni_device_routes/pci-6220.o \
+					   ni_routing/ni_device_routes/pci-6221.o \
+					   ni_routing/ni_device_routes/pxi-6224.o \
+					   ni_routing/ni_device_routes/pxi-6225.o \
+					   ni_routing/ni_device_routes/pci-6229.o \
+					   ni_routing/ni_device_routes/pci-6251.o \
+					   ni_routing/ni_device_routes/pxi-6251.o \
+					   ni_routing/ni_device_routes/pxie-6251.o \
+					   ni_routing/ni_device_routes/pci-6254.o \
+					   ni_routing/ni_device_routes/pci-6259.o \
+					   ni_routing/ni_device_routes/pci-6534.o \
+					   ni_routing/ni_device_routes/pxie-6535.o \
+					   ni_routing/ni_device_routes/pci-6602.o \
+					   ni_routing/ni_device_routes/pci-6713.o \
+					   ni_routing/ni_device_routes/pci-6723.o \
+					   ni_routing/ni_device_routes/pci-6733.o \
+					   ni_routing/ni_device_routes/pxi-6733.o \
+					   ni_routing/ni_device_routes/pxie-6738.o
 obj-$(CONFIG_COMEDI_NI_LABPC)		+= ni_labpc_common.o
 obj-$(CONFIG_COMEDI_NI_LABPC_ISADMA)	+= ni_labpc_isadma.o
 

drivers/staging/comedi/drivers/ni_routes.h

@@ -0,0 +1,329 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/* vim: set ts=8 sw=8 noet tw=80 nowrap: */
+/*
+ *  comedi/drivers/ni_routes.h
+ *  Route information for NI boards.
+ *
+ *  COMEDI - Linux Control and Measurement Device Interface
+ *  Copyright (C) 2016 Spencer E. Olson <olsonse@umich.edu>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ */
+
+#ifndef _COMEDI_DRIVERS_NI_ROUTES_H
+#define _COMEDI_DRIVERS_NI_ROUTES_H
+
+#include <linux/types.h>
+#include <linux/errno.h>
+
+#ifndef NI_ROUTE_VALUE_EXTERNAL_CONVERSION
+#include <linux/bitops.h>
+#endif
+
+#include "../comedi.h"
+
+/**
+ * struct ni_route_set - Set of destinations with a common source.
+ * @dest: Destination of all sources in this route set.
+ * @n_src: Number of sources for this route set.
+ * @src: List of sources that all map to the same destination.
+ */
+struct ni_route_set {
+	int dest;
+	int n_src;
+	int *src;
+};
+
+/**
+ * struct ni_device_routes - List of all src->dest sets for a particular device.
+ * @device: Name of board/device (e.g. pxi-6733).
+ * @n_route_sets: Number of route sets that are valid for this device.
+ * @routes: List of route sets that are valid for this device.
+ */
+struct ni_device_routes {
+	const char *device;
+	int n_route_sets;
+	struct ni_route_set *routes;
+};
+
+/**
+ * struct ni_route_tables - Register values and valid routes for a device.
+ * @valid_routes: Pointer to a all valid route sets for a single device.
+ * @route_values: Pointer to register values for all routes for the family to
+ *		  which the device belongs.
+ *
+ * Link to the valid src->dest routes and the register values used to assign
+ * such routes for that particular device.
+ */
+struct ni_route_tables {
+	const struct ni_device_routes *valid_routes;
+	const u8 *route_values;
+};
+
+/*
+ * ni_assign_device_routes() - Assign the proper lookup table for NI signal
+ *			       routing to the specified NI device.
+ *
+ * Return: -ENODATA if assignment was not successful; 0 if successful.
+ */
+int ni_assign_device_routes(const char *device_family,
+			    const char *board_name,
+			    struct ni_route_tables *tables);
+
+/*
+ * ni_find_route_set() - Finds the proper route set with the specified
+ *			 destination.
+ * @destination: Destination of which to search for the route set.
+ * @valid_routes: Pointer to device routes within which to search.
+ *
+ * Return: NULL if no route_set is found with the specified @destination;
+ *	otherwise, a pointer to the route_set if found.
+ */
+const struct ni_route_set *
+ni_find_route_set(const int destination,
+		  const struct ni_device_routes *valid_routes);
+
+/*
+ * ni_route_set_has_source() - Determines whether the given source is in
+ *			       included given route_set.
+ *
+ * Return: true if found; false otherwise.
+ */
+bool ni_route_set_has_source(const struct ni_route_set *routes, const int src);
+
+/*
+ * ni_route_to_register() - Validates and converts the specified signal route
+ *			    (src-->dest) to the value used at the appropriate
+ *			    register.
+ * @src:	global-identifier for route source
+ * @dest:	global-identifier for route destination
+ * @tables:	pointer to relevant set of routing tables.
+ *
+ * Generally speaking, most routes require the first six bits and a few require
+ * 7 bits.  Special handling is given for the return value when the route is to
+ * be handled by the RTSI sub-device.  In this case, the returned register may
+ * not be sufficient to define the entire route path, but rather may only
+ * indicate the intermediate route.  For example, if the route must go through
+ * the RGOUT0 pin, the (src->RGOUT0) register value will be returned.
+ * Similarly, if the route must go through the NI_RTSI_BRD lines, the BIT(6)
+ * will be set:
+ *
+ * if route does not need RTSI_BRD lines:
+ *   bits 0:7 : register value
+ *              for a route that must go through RGOUT0 pin, this will be equal
+ *              to the (src->RGOUT0) register value.
+ * else: * route is (src->RTSI_BRD(x), RTSI_BRD(x)->TRIGGER_LINE(i)) *
+ *   bits 0:5 : zero
+ *   bits 6   : set to 1
+ *   bits 7:7 : zero
+ *
+ * Return: register value to be used for source at destination with special
+ *	cases given above; Otherwise, -1 if the specified route is not valid for
+ *	this particular device.
+ */
+s8 ni_route_to_register(const int src, const int dest,
+			const struct ni_route_tables *tables);
+
+static inline bool ni_rtsi_route_requires_mux(s8 value)
+{
+	return value & BIT(6);
+}
+
+/*
+ * ni_lookup_route_register() - Look up a register value for a particular route
+ *				without checking whether the route is valid for
+ *				the particular device.
+ * @src:	global-identifier for route source
+ * @dest:	global-identifier for route destination
+ * @tables:	pointer to relevant set of routing tables.
+ *
+ * Return: -EINVAL if the specified route is not valid for this device family.
+ */
+s8 ni_lookup_route_register(int src, int dest,
+			    const struct ni_route_tables *tables);
+
+/**
+ * route_is_valid() - Determines whether the specified signal route (src-->dest)
+ *		      is valid for the given NI comedi_device.
+ * @src:	global-identifier for route source
+ * @dest:	global-identifier for route destination
+ * @tables:	pointer to relevant set of routing tables.
+ *
+ * Return: True if the route is valid, otherwise false.
+ */
+static inline bool route_is_valid(const int src, const int dest,
+				  const struct ni_route_tables *tables)
+{
+	return ni_route_to_register(src, dest, tables) >= 0;
+}
+
+/*
+ * ni_is_cmd_dest() - Determine whether the given destination is only
+ *		      configurable via a comedi_cmd struct.
+ * @dest: Destination to test.
+ */
+bool ni_is_cmd_dest(int dest);
+
+static inline bool channel_is_pfi(int channel)
+{
+	return NI_PFI(0) <= channel && channel <= NI_PFI(-1);
+}
+
+static inline bool channel_is_rtsi(int channel)
+{
+	return TRIGGER_LINE(0) <= channel && channel <= TRIGGER_LINE(-1);
+}
+
+static inline bool channel_is_ctr(int channel)
+{
+	return channel >= NI_COUNTER_NAMES_BASE &&
+	       channel <= NI_COUNTER_NAMES_MAX;
+}
+
+/*
+ * ni_count_valid_routes() - Count the number of valid routes.
+ * @tables: Routing tables for which to count all valid routes.
+ */
+unsigned int ni_count_valid_routes(const struct ni_route_tables *tables);
+
+/*
+ * ni_get_valid_routes() - Implements INSN_DEVICE_CONFIG_GET_ROUTES.
+ * @tables:	pointer to relevant set of routing tables.
+ * @n_pairs:	Number of pairs for which memory is allocated by the user.  If
+ *		the user specifies '0', only the number of available pairs is
+ *		returned.
+ * @pair_data:	Pointer to memory allocated to return pairs back to user.  Each
+ *		even, odd indexed member of this array will hold source,
+ *		destination of a route pair respectively.
+ *
+ * Return: the number of valid routes if n_pairs == 0; otherwise, the number of
+ *	valid routes copied.
+ */
+unsigned int ni_get_valid_routes(const struct ni_route_tables *tables,
+				 unsigned int n_pairs,
+				 unsigned int *pair_data);
+
+/*
+ * ni_sort_device_routes() - Sort the list of valid device signal routes in
+ *			     preparation for use.
+ * @valid_routes:	pointer to ni_device_routes struct to sort.
+ */
+void ni_sort_device_routes(struct ni_device_routes *valid_routes);
+
+/*
+ * ni_find_route_source() - Finds the signal source corresponding to a signal
+ *			    route (src-->dest) of the specified routing register
+ *			    value and the specified route destination on the
+ *			    specified device.
+ *
+ * Note that this function does _not_ validate the source based on device
+ * routes.
+ *
+ * Return: The NI signal value (e.g. NI_PFI(0) or PXI_Clk10) if found.
+ *	If the source was not found (i.e. the register value is not
+ *	valid for any routes to the destination), -EINVAL is returned.
+ */
+int ni_find_route_source(const u8 src_sel_reg_value, const int dest,
+			 const struct ni_route_tables *tables);
+
+/**
+ * route_register_is_valid() - Determines whether the register value for the
+ *			       specified route destination on the specified
+ *			       device is valid.
+ */
+static inline bool route_register_is_valid(const u8 src_sel_reg_value,
+					   const int dest,
+					   const struct ni_route_tables *tables)
+{
+	return ni_find_route_source(src_sel_reg_value, dest, tables) >= 0;
+}
+
+/**
+ * ni_get_reg_value_roffs() - Determines the proper register value for a
+ *			      particular valid NI signal/terminal route.
+ * @src:	Either a direct register value or one of NI_* signal names.
+ * @dest:	global-identifier for route destination
+ * @tables:	pointer to relevant set of routing tables.
+ * @direct_reg_offset:
+ *		Compatibility compensation argument.  This argument allows us to
+ *		arbitrarily apply an offset to src if src is a direct register
+ *		value reference.  This is necessary to be compatible with
+ *		definitions of register values as previously exported directly
+ *		to user space.
+ *
+ * Return: the register value (>0) to be used at the destination if the src is
+ *	valid for the given destination; -1 otherwise.
+ */
+static inline s8 ni_get_reg_value_roffs(int src, const int dest,
+					const struct ni_route_tables *tables,
+					const int direct_reg_offset)
+{
+	if (src < NI_NAMES_BASE) {
+		src += direct_reg_offset;
+		/*
+		 * In this case, the src is expected to actually be a register
+		 * value.
+		 */
+		if (route_register_is_valid(src, dest, tables))
+			return src;
+		return -1;
+	}
+
+	/*
+	 * Otherwise, the src is expected to be one of the abstracted NI
+	 * signal/terminal names.
+	 */
+	return ni_route_to_register(src, dest, tables);
+}
+
+static inline int ni_get_reg_value(const int src, const int dest,
+				   const struct ni_route_tables *tables)
+{
+	return ni_get_reg_value_roffs(src, dest, tables, 0);
+}
+
+/**
+ * ni_check_trigger_arg_roffs() - Checks the trigger argument (*_arg) of an NI
+ *				  device to ensure that the *_arg value
+ *				  corresponds to _either_ a valid register value
+ *				  to define a trigger source, _or_ a valid NI
+ *				  signal/terminal name that has a valid route to
+ *				  the destination on the particular device.
+ * @src:	Either a direct register value or one of NI_* signal names.
+ * @dest:	global-identifier for route destination
+ * @tables:	pointer to relevant set of routing tables.
+ * @direct_reg_offset:
+ *		Compatibility compensation argument.  This argument allows us to
+ *		arbitrarily apply an offset to src if src is a direct register
+ *		value reference.  This is necessary to be compatible with
+ *		definitions of register values as previously exported directly
+ *		to user space.
+ *
+ * Return: 0 if the src (either register value or NI signal/terminal name) is
+ *	valid for the destination; -EINVAL otherwise.
+ */
+static inline
+int ni_check_trigger_arg_roffs(int src, const int dest,
+			       const struct ni_route_tables *tables,
+			       const int direct_reg_offset)
+{
+	if (ni_get_reg_value_roffs(src, dest, tables, direct_reg_offset) < 0)
+		return -EINVAL;
+	return 0;
+}
+
+static inline int ni_check_trigger_arg(const int src, const int dest,
+				       const struct ni_route_tables *tables)
+{
+	return ni_check_trigger_arg_roffs(src, dest, tables, 0);
+}
+
+#endif /* _COMEDI_DRIVERS_NI_ROUTES_H */

drivers/staging/comedi/drivers/ni_stc.h

@@ -15,6 +15,7 @@
 #define _COMEDI_NI_STC_H
 
 #include "ni_tio.h"
+#include "ni_routes.h"
 
 /*
  * Registers in the National Instruments DAQ-STC chip
@@ -1058,6 +1059,9 @@ struct ni_private {
 	 * possible.
 	 */
 	unsigned int ao_needs_arming:1;
+
+	/* device signal route tables */
+	struct ni_route_tables routing_tables;
 };
 
 static const struct comedi_lrange range_ni_E_ao_ext;

drivers/staging/comedi/drivers/tests/Makefile

@@ -3,4 +3,5 @@
 #
 ccflags-$(CONFIG_COMEDI_DEBUG)		:= -DDEBUG
 
-obj-$(CONFIG_COMEDI_TESTS)		+= example_test.o
+obj-$(CONFIG_COMEDI_TESTS)		+= example_test.o ni_routes_test.o
+CFLAGS_ni_routes_test.o			:= -DDEBUG