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1/* SPDX-License-Identifier: GPL-2.0+ */2/*3 * comedi_8254.h4 * Generic 8254 timer/counter support5 * Copyright (C) 2014 H Hartley Sweeten <hsweeten@visionengravers.com>6 *7 * COMEDI - Linux Control and Measurement Device Interface8 * Copyright (C) 2000 David A. Schleef <ds@schleef.org>9 */10 11#ifndef _COMEDI_8254_H12#define _COMEDI_8254_H13 14#include <linux/types.h>15#include <linux/errno.h>16#include <linux/err.h>17 18struct comedi_device;19struct comedi_insn;20struct comedi_subdevice;21 22/*23 * Common oscillator base values in nanoseconds24 */25#define I8254_OSC_BASE_10MHZ 10026#define I8254_OSC_BASE_5MHZ 20027#define I8254_OSC_BASE_4MHZ 25028#define I8254_OSC_BASE_2MHZ 50029#define I8254_OSC_BASE_1MHZ 100030#define I8254_OSC_BASE_100KHZ 1000031#define I8254_OSC_BASE_10KHZ 10000032#define I8254_OSC_BASE_1KHZ 100000033 34/*35 * I/O access size used to read/write registers36 */37#define I8254_IO8 138#define I8254_IO16 239#define I8254_IO32 440 41/*42 * Register map for generic 8254 timer (I8254_IO8 with 0 regshift)43 */44#define I8254_COUNTER0_REG 0x0045#define I8254_COUNTER1_REG 0x0146#define I8254_COUNTER2_REG 0x0247#define I8254_CTRL_REG 0x0348#define I8254_CTRL_SEL_CTR(x) ((x) << 6)49#define I8254_CTRL_READBACK(x) (I8254_CTRL_SEL_CTR(3) | BIT(x))50#define I8254_CTRL_READBACK_COUNT I8254_CTRL_READBACK(4)51#define I8254_CTRL_READBACK_STATUS I8254_CTRL_READBACK(5)52#define I8254_CTRL_READBACK_SEL_CTR(x) (2 << (x))53#define I8254_CTRL_RW(x) (((x) & 0x3) << 4)54#define I8254_CTRL_LATCH I8254_CTRL_RW(0)55#define I8254_CTRL_LSB_ONLY I8254_CTRL_RW(1)56#define I8254_CTRL_MSB_ONLY I8254_CTRL_RW(2)57#define I8254_CTRL_LSB_MSB I8254_CTRL_RW(3)58 59/* counter maps zero to 0x10000 */60#define I8254_MAX_COUNT 0x1000061 62struct comedi_8254;63 64/**65 * typedef comedi_8254_iocb_fn - call-back function type for 8254 register access66 * @i8254: pointer to struct comedi_825467 * @dir: direction (0 = read, 1 = write)68 * @reg: register number69 * @val: value to write70 *71 * Return: Register value when reading, 0 when writing.72 */73typedef unsigned int comedi_8254_iocb_fn(struct comedi_8254 *i8254, int dir,74 unsigned int reg, unsigned int val);75 76/**77 * struct comedi_8254 - private data used by this module78 * @iocb: I/O call-back function for register access79 * @context: context for register access (e.g. a base address)80 * @iosize: I/O size used to access the registers (b/w/l)81 * @regshift: register gap shift82 * @osc_base: cascaded oscillator speed in ns83 * @divisor: divisor for single counter84 * @divisor1: divisor loaded into first cascaded counter85 * @divisor2: divisor loaded into second cascaded counter86 * #next_div: next divisor for single counter87 * @next_div1: next divisor to use for first cascaded counter88 * @next_div2: next divisor to use for second cascaded counter89 * @clock_src; current clock source for each counter (driver specific)90 * @gate_src; current gate source for each counter (driver specific)91 * @busy: flags used to indicate that a counter is "busy"92 * @insn_config: driver specific (*insn_config) callback93 */94struct comedi_8254 {95 comedi_8254_iocb_fn *iocb;96 unsigned long context;97 unsigned int iosize;98 unsigned int regshift;99 unsigned int osc_base;100 unsigned int divisor;101 unsigned int divisor1;102 unsigned int divisor2;103 unsigned int next_div;104 unsigned int next_div1;105 unsigned int next_div2;106 unsigned int clock_src[3];107 unsigned int gate_src[3];108 bool busy[3];109 110 int (*insn_config)(struct comedi_device *dev,111 struct comedi_subdevice *s,112 struct comedi_insn *insn, unsigned int *data);113};114 115unsigned int comedi_8254_status(struct comedi_8254 *i8254,116 unsigned int counter);117unsigned int comedi_8254_read(struct comedi_8254 *i8254, unsigned int counter);118void comedi_8254_write(struct comedi_8254 *i8254,119 unsigned int counter, unsigned int val);120 121int comedi_8254_set_mode(struct comedi_8254 *i8254,122 unsigned int counter, unsigned int mode);123int comedi_8254_load(struct comedi_8254 *i8254,124 unsigned int counter, unsigned int val, unsigned int mode);125 126void comedi_8254_pacer_enable(struct comedi_8254 *i8254,127 unsigned int counter1, unsigned int counter2,128 bool enable);129void comedi_8254_update_divisors(struct comedi_8254 *i8254);130void comedi_8254_cascade_ns_to_timer(struct comedi_8254 *i8254,131 unsigned int *nanosec, unsigned int flags);132void comedi_8254_ns_to_timer(struct comedi_8254 *i8254,133 unsigned int *nanosec, unsigned int flags);134 135void comedi_8254_set_busy(struct comedi_8254 *i8254,136 unsigned int counter, bool busy);137 138void comedi_8254_subdevice_init(struct comedi_subdevice *s,139 struct comedi_8254 *i8254);140 141#ifdef CONFIG_HAS_IOPORT142struct comedi_8254 *comedi_8254_io_alloc(unsigned long iobase,143 unsigned int osc_base,144 unsigned int iosize,145 unsigned int regshift);146#else147static inline struct comedi_8254 *comedi_8254_io_alloc(unsigned long iobase,148 unsigned int osc_base,149 unsigned int iosize,150 unsigned int regshift)151{152 return ERR_PTR(-ENXIO);153}154#endif155 156struct comedi_8254 *comedi_8254_mm_alloc(void __iomem *mmio,157 unsigned int osc_base,158 unsigned int iosize,159 unsigned int regshift);160 161#endif /* _COMEDI_8254_H */162