comedi: Move "comedi_8254.h" to <linux/comedi/comedi_8254.h>

Some of the header files in "drivers/comedi/drivers/" are common enough
to be useful to out-of-tree comedi driver modules.  Using them for
out-of-tree module builds is hampered by the headers being outside the
"include/" directory so it is desirable to move them.

There are about a couple of dozen or so Comedi device drivers that use
the "comedi_8254" module to add timers based on the venerable 8254
Programmable Interval Timer chip.  The macros and declarations to use
that module are in the "comedi_8254.h" header file in the comedi
"drivers" directory.  Move it into "include/linux/comedi/".

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20211117120604.117740-5-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 134 insertions, 0 deletions

diff --git a/include/linux/comedi/comedi_8254.h b/include/linux/comedi/comedi_8254.h
new file mode 100644
index 000000000000..d8264417e53c
--- /dev/null
+++ b/include/linux/comedi/comedi_8254.h
@@ -0,0 +1,134 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * comedi_8254.h
+ * Generic 8254 timer/counter support
+ * Copyright (C) 2014 H Hartley Sweeten <hsweeten@visionengravers.com>
+ *
+ * COMEDI - Linux Control and Measurement Device Interface
+ * Copyright (C) 2000 David A. Schleef <ds@schleef.org>
+ */
+
+#ifndef _COMEDI_8254_H
+#define _COMEDI_8254_H
+
+#include <linux/types.h>
+
+struct comedi_device;
+struct comedi_insn;
+struct comedi_subdevice;
+
+/*
+ * Common oscillator base values in nanoseconds
+ */
+#define I8254_OSC_BASE_10MHZ	100
+#define I8254_OSC_BASE_5MHZ	200
+#define I8254_OSC_BASE_4MHZ	250
+#define I8254_OSC_BASE_2MHZ	500
+#define I8254_OSC_BASE_1MHZ	1000
+#define I8254_OSC_BASE_100KHZ	10000
+#define I8254_OSC_BASE_10KHZ	100000
+#define I8254_OSC_BASE_1KHZ	1000000
+
+/*
+ * I/O access size used to read/write registers
+ */
+#define I8254_IO8		1
+#define I8254_IO16		2
+#define I8254_IO32		4
+
+/*
+ * Register map for generic 8254 timer (I8254_IO8 with 0 regshift)
+ */
+#define I8254_COUNTER0_REG		0x00
+#define I8254_COUNTER1_REG		0x01
+#define I8254_COUNTER2_REG		0x02
+#define I8254_CTRL_REG			0x03
+#define I8254_CTRL_SEL_CTR(x)		((x) << 6)
+#define I8254_CTRL_READBACK(x)		(I8254_CTRL_SEL_CTR(3) | BIT(x))
+#define I8254_CTRL_READBACK_COUNT	I8254_CTRL_READBACK(4)
+#define I8254_CTRL_READBACK_STATUS	I8254_CTRL_READBACK(5)
+#define I8254_CTRL_READBACK_SEL_CTR(x)	(2 << (x))
+#define I8254_CTRL_RW(x)		(((x) & 0x3) << 4)
+#define I8254_CTRL_LATCH		I8254_CTRL_RW(0)
+#define I8254_CTRL_LSB_ONLY		I8254_CTRL_RW(1)
+#define I8254_CTRL_MSB_ONLY		I8254_CTRL_RW(2)
+#define I8254_CTRL_LSB_MSB		I8254_CTRL_RW(3)
+
+/* counter maps zero to 0x10000 */
+#define I8254_MAX_COUNT			0x10000
+
+/**
+ * struct comedi_8254 - private data used by this module
+ * @iobase:		PIO base address of the registers (in/out)
+ * @mmio:		MMIO base address of the registers (read/write)
+ * @iosize:		I/O size used to access the registers (b/w/l)
+ * @regshift:		register gap shift
+ * @osc_base:		cascaded oscillator speed in ns
+ * @divisor:		divisor for single counter
+ * @divisor1:		divisor loaded into first cascaded counter
+ * @divisor2:		divisor loaded into second cascaded counter
+ * #next_div:		next divisor for single counter
+ * @next_div1:		next divisor to use for first cascaded counter
+ * @next_div2:		next divisor to use for second cascaded counter
+ * @clock_src;		current clock source for each counter (driver specific)
+ * @gate_src;		current gate source  for each counter (driver specific)
+ * @busy:		flags used to indicate that a counter is "busy"
+ * @insn_config:	driver specific (*insn_config) callback
+ */
+struct comedi_8254 {
+	unsigned long iobase;
+	void __iomem *mmio;
+	unsigned int iosize;
+	unsigned int regshift;
+	unsigned int osc_base;
+	unsigned int divisor;
+	unsigned int divisor1;
+	unsigned int divisor2;
+	unsigned int next_div;
+	unsigned int next_div1;
+	unsigned int next_div2;
+	unsigned int clock_src[3];
+	unsigned int gate_src[3];
+	bool busy[3];
+
+	int (*insn_config)(struct comedi_device *dev,
+			   struct comedi_subdevice *s,
+			   struct comedi_insn *insn, unsigned int *data);
+};
+
+unsigned int comedi_8254_status(struct comedi_8254 *i8254,
+				unsigned int counter);
+unsigned int comedi_8254_read(struct comedi_8254 *i8254, unsigned int counter);
+void comedi_8254_write(struct comedi_8254 *i8254,
+		       unsigned int counter, unsigned int val);
+
+int comedi_8254_set_mode(struct comedi_8254 *i8254,
+			 unsigned int counter, unsigned int mode);
+int comedi_8254_load(struct comedi_8254 *i8254,
+		     unsigned int counter, unsigned int val, unsigned int mode);
+
+void comedi_8254_pacer_enable(struct comedi_8254 *i8254,
+			      unsigned int counter1, unsigned int counter2,
+			      bool enable);
+void comedi_8254_update_divisors(struct comedi_8254 *i8254);
+void comedi_8254_cascade_ns_to_timer(struct comedi_8254 *i8254,
+				     unsigned int *nanosec, unsigned int flags);
+void comedi_8254_ns_to_timer(struct comedi_8254 *i8254,
+			     unsigned int *nanosec, unsigned int flags);
+
+void comedi_8254_set_busy(struct comedi_8254 *i8254,
+			  unsigned int counter, bool busy);
+
+void comedi_8254_subdevice_init(struct comedi_subdevice *s,
+				struct comedi_8254 *i8254);
+
+struct comedi_8254 *comedi_8254_init(unsigned long iobase,
+				     unsigned int osc_base,
+				     unsigned int iosize,
+				     unsigned int regshift);
+struct comedi_8254 *comedi_8254_mm_init(void __iomem *mmio,
+					unsigned int osc_base,
+					unsigned int iosize,
+					unsigned int regshift);
+
+#endif	/* _COMEDI_8254_H */