162 lines
		
	
	
		
			5.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			162 lines
		
	
	
		
			5.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0+ */
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| /*
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|  * comedi_8254.h
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|  * Generic 8254 timer/counter support
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|  * Copyright (C) 2014 H Hartley Sweeten <hsweeten@visionengravers.com>
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|  *
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|  * COMEDI - Linux Control and Measurement Device Interface
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|  * Copyright (C) 2000 David A. Schleef <ds@schleef.org>
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|  */
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| 
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| #ifndef _COMEDI_8254_H
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| #define _COMEDI_8254_H
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| 
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| #include <linux/types.h>
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| #include <linux/errno.h>
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| #include <linux/err.h>
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| 
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| struct comedi_device;
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| struct comedi_insn;
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| struct comedi_subdevice;
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| 
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| /*
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|  * Common oscillator base values in nanoseconds
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|  */
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| #define I8254_OSC_BASE_10MHZ	100
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| #define I8254_OSC_BASE_5MHZ	200
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| #define I8254_OSC_BASE_4MHZ	250
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| #define I8254_OSC_BASE_2MHZ	500
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| #define I8254_OSC_BASE_1MHZ	1000
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| #define I8254_OSC_BASE_100KHZ	10000
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| #define I8254_OSC_BASE_10KHZ	100000
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| #define I8254_OSC_BASE_1KHZ	1000000
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| 
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| /*
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|  * I/O access size used to read/write registers
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|  */
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| #define I8254_IO8		1
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| #define I8254_IO16		2
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| #define I8254_IO32		4
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| 
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| /*
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|  * Register map for generic 8254 timer (I8254_IO8 with 0 regshift)
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|  */
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| #define I8254_COUNTER0_REG		0x00
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| #define I8254_COUNTER1_REG		0x01
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| #define I8254_COUNTER2_REG		0x02
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| #define I8254_CTRL_REG			0x03
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| #define I8254_CTRL_SEL_CTR(x)		((x) << 6)
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| #define I8254_CTRL_READBACK(x)		(I8254_CTRL_SEL_CTR(3) | BIT(x))
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| #define I8254_CTRL_READBACK_COUNT	I8254_CTRL_READBACK(4)
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| #define I8254_CTRL_READBACK_STATUS	I8254_CTRL_READBACK(5)
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| #define I8254_CTRL_READBACK_SEL_CTR(x)	(2 << (x))
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| #define I8254_CTRL_RW(x)		(((x) & 0x3) << 4)
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| #define I8254_CTRL_LATCH		I8254_CTRL_RW(0)
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| #define I8254_CTRL_LSB_ONLY		I8254_CTRL_RW(1)
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| #define I8254_CTRL_MSB_ONLY		I8254_CTRL_RW(2)
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| #define I8254_CTRL_LSB_MSB		I8254_CTRL_RW(3)
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| 
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| /* counter maps zero to 0x10000 */
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| #define I8254_MAX_COUNT			0x10000
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| 
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| struct comedi_8254;
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| 
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| /**
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|  * typedef comedi_8254_iocb_fn - call-back function type for 8254 register access
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|  * @i8254:		pointer to struct comedi_8254
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|  * @dir:		direction (0 = read, 1 = write)
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|  * @reg:		register number
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|  * @val:		value to write
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|  *
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|  * Return: Register value when reading, 0 when writing.
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|  */
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| typedef unsigned int comedi_8254_iocb_fn(struct comedi_8254 *i8254, int dir,
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| 					 unsigned int reg, unsigned int val);
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| 
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| /**
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|  * struct comedi_8254 - private data used by this module
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|  * @iocb:		I/O call-back function for register access
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|  * @context:		context for register access (e.g. a base address)
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|  * @iosize:		I/O size used to access the registers (b/w/l)
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|  * @regshift:		register gap shift
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|  * @osc_base:		cascaded oscillator speed in ns
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|  * @divisor:		divisor for single counter
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|  * @divisor1:		divisor loaded into first cascaded counter
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|  * @divisor2:		divisor loaded into second cascaded counter
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|  * #next_div:		next divisor for single counter
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|  * @next_div1:		next divisor to use for first cascaded counter
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|  * @next_div2:		next divisor to use for second cascaded counter
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|  * @clock_src;		current clock source for each counter (driver specific)
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|  * @gate_src;		current gate source  for each counter (driver specific)
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|  * @busy:		flags used to indicate that a counter is "busy"
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|  * @insn_config:	driver specific (*insn_config) callback
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|  */
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| struct comedi_8254 {
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| 	comedi_8254_iocb_fn *iocb;
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| 	unsigned long context;
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| 	unsigned int iosize;
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| 	unsigned int regshift;
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| 	unsigned int osc_base;
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| 	unsigned int divisor;
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| 	unsigned int divisor1;
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| 	unsigned int divisor2;
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| 	unsigned int next_div;
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| 	unsigned int next_div1;
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| 	unsigned int next_div2;
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| 	unsigned int clock_src[3];
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| 	unsigned int gate_src[3];
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| 	bool busy[3];
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| 
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| 	int (*insn_config)(struct comedi_device *dev,
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| 			   struct comedi_subdevice *s,
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| 			   struct comedi_insn *insn, unsigned int *data);
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| };
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| 
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| unsigned int comedi_8254_status(struct comedi_8254 *i8254,
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| 				unsigned int counter);
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| unsigned int comedi_8254_read(struct comedi_8254 *i8254, unsigned int counter);
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| void comedi_8254_write(struct comedi_8254 *i8254,
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| 		       unsigned int counter, unsigned int val);
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| 
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| int comedi_8254_set_mode(struct comedi_8254 *i8254,
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| 			 unsigned int counter, unsigned int mode);
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| int comedi_8254_load(struct comedi_8254 *i8254,
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| 		     unsigned int counter, unsigned int val, unsigned int mode);
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| 
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| void comedi_8254_pacer_enable(struct comedi_8254 *i8254,
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| 			      unsigned int counter1, unsigned int counter2,
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| 			      bool enable);
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| void comedi_8254_update_divisors(struct comedi_8254 *i8254);
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| void comedi_8254_cascade_ns_to_timer(struct comedi_8254 *i8254,
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| 				     unsigned int *nanosec, unsigned int flags);
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| void comedi_8254_ns_to_timer(struct comedi_8254 *i8254,
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| 			     unsigned int *nanosec, unsigned int flags);
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| 
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| void comedi_8254_set_busy(struct comedi_8254 *i8254,
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| 			  unsigned int counter, bool busy);
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| 
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| void comedi_8254_subdevice_init(struct comedi_subdevice *s,
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| 				struct comedi_8254 *i8254);
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| 
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| #ifdef CONFIG_HAS_IOPORT
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| struct comedi_8254 *comedi_8254_io_alloc(unsigned long iobase,
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| 					 unsigned int osc_base,
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| 					 unsigned int iosize,
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| 					 unsigned int regshift);
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| #else
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| static inline struct comedi_8254 *comedi_8254_io_alloc(unsigned long iobase,
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| 						       unsigned int osc_base,
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| 						       unsigned int iosize,
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| 						       unsigned int regshift)
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| {
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| 	return ERR_PTR(-ENXIO);
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| }
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| #endif
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| 
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| struct comedi_8254 *comedi_8254_mm_alloc(void __iomem *mmio,
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| 					 unsigned int osc_base,
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| 					 unsigned int iosize,
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| 					 unsigned int regshift);
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| 
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| #endif	/* _COMEDI_8254_H */
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