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/* SPDX-License-Identifier: GPL-2.0+ */
/*
* comedi_8254.h
* Generic 8254 timer/counter support
* Copyright (C) 2014 H Hartley Sweeten <[email protected]>
*
* COMEDI - Linux Control and Measurement Device Interface
* Copyright (C) 2000 David A. Schleef <[email protected]>
*/
#ifndef _COMEDI_8254_H
#define _COMEDI_8254_H
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/err.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;
/**
* typedef comedi_8254_iocb_fn - call-back function type for 8254 register access
* @i8254: pointer to struct comedi_8254
* @dir: direction (0 = read, 1 = write)
* @reg: register number
* @val: value to write
*
* Return: Register value when reading, 0 when writing.
*/
typedef unsigned int comedi_8254_iocb_fn(struct comedi_8254 *i8254, int dir,
unsigned int reg, unsigned int val);
/**
* struct comedi_8254 - private data used by this module
* @iocb: I/O call-back function for register access
* @context: context for register access (e.g. a base address)
* @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 {
comedi_8254_iocb_fn *iocb;
unsigned long context;
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);
#ifdef CONFIG_HAS_IOPORT
struct comedi_8254 *comedi_8254_io_alloc(unsigned long iobase,
unsigned int osc_base,
unsigned int iosize,
unsigned int regshift);
#else
static inline struct comedi_8254 *comedi_8254_io_alloc(unsigned long iobase,
unsigned int osc_base,
unsigned int iosize,
unsigned int regshift)
{
return ERR_PTR(-ENXIO);
}
#endif
struct comedi_8254 *comedi_8254_mm_alloc(void __iomem *mmio,
unsigned int osc_base,
unsigned int iosize,
unsigned int regshift);
#endif /* _COMEDI_8254_H */
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