1 /* SPDX-License-Identifier: GPL-2.0+ */ 2 /* 3 * comedi_8254.h 4 * Generic 8254 timer/counter support 5 * Copyright (C) 2014 H Hartley Sweeten <hsweeten@visionengravers.com> 6 * 7 * COMEDI - Linux Control and Measurement Device Interface 8 * Copyright (C) 2000 David A. Schleef <ds@schleef.org> 9 */ 10 11 #ifndef _COMEDI_8254_H 12 #define _COMEDI_8254_H 13 14 #include <linux/types.h> 15 16 struct comedi_device; 17 struct comedi_insn; 18 struct comedi_subdevice; 19 20 /* 21 * Common oscillator base values in nanoseconds 22 */ 23 #define I8254_OSC_BASE_10MHZ 100 24 #define I8254_OSC_BASE_5MHZ 200 25 #define I8254_OSC_BASE_4MHZ 250 26 #define I8254_OSC_BASE_2MHZ 500 27 #define I8254_OSC_BASE_1MHZ 1000 28 #define I8254_OSC_BASE_100KHZ 10000 29 #define I8254_OSC_BASE_10KHZ 100000 30 #define I8254_OSC_BASE_1KHZ 1000000 31 32 /* 33 * I/O access size used to read/write registers 34 */ 35 #define I8254_IO8 1 36 #define I8254_IO16 2 37 #define I8254_IO32 4 38 39 /* 40 * Register map for generic 8254 timer (I8254_IO8 with 0 regshift) 41 */ 42 #define I8254_COUNTER0_REG 0x00 43 #define I8254_COUNTER1_REG 0x01 44 #define I8254_COUNTER2_REG 0x02 45 #define I8254_CTRL_REG 0x03 46 #define I8254_CTRL_SEL_CTR(x) ((x) << 6) 47 #define I8254_CTRL_READBACK(x) (I8254_CTRL_SEL_CTR(3) | BIT(x)) 48 #define I8254_CTRL_READBACK_COUNT I8254_CTRL_READBACK(4) 49 #define I8254_CTRL_READBACK_STATUS I8254_CTRL_READBACK(5) 50 #define I8254_CTRL_READBACK_SEL_CTR(x) (2 << (x)) 51 #define I8254_CTRL_RW(x) (((x) & 0x3) << 4) 52 #define I8254_CTRL_LATCH I8254_CTRL_RW(0) 53 #define I8254_CTRL_LSB_ONLY I8254_CTRL_RW(1) 54 #define I8254_CTRL_MSB_ONLY I8254_CTRL_RW(2) 55 #define I8254_CTRL_LSB_MSB I8254_CTRL_RW(3) 56 57 /* counter maps zero to 0x10000 */ 58 #define I8254_MAX_COUNT 0x10000 59 60 /** 61 * struct comedi_8254 - private data used by this module 62 * @iobase: PIO base address of the registers (in/out) 63 * @mmio: MMIO base address of the registers (read/write) 64 * @iosize: I/O size used to access the registers (b/w/l) 65 * @regshift: register gap shift 66 * @osc_base: cascaded oscillator speed in ns 67 * @divisor: divisor for single counter 68 * @divisor1: divisor loaded into first cascaded counter 69 * @divisor2: divisor loaded into second cascaded counter 70 * #next_div: next divisor for single counter 71 * @next_div1: next divisor to use for first cascaded counter 72 * @next_div2: next divisor to use for second cascaded counter 73 * @clock_src; current clock source for each counter (driver specific) 74 * @gate_src; current gate source for each counter (driver specific) 75 * @busy: flags used to indicate that a counter is "busy" 76 * @insn_config: driver specific (*insn_config) callback 77 */ 78 struct comedi_8254 { 79 unsigned long iobase; 80 void __iomem *mmio; 81 unsigned int iosize; 82 unsigned int regshift; 83 unsigned int osc_base; 84 unsigned int divisor; 85 unsigned int divisor1; 86 unsigned int divisor2; 87 unsigned int next_div; 88 unsigned int next_div1; 89 unsigned int next_div2; 90 unsigned int clock_src[3]; 91 unsigned int gate_src[3]; 92 bool busy[3]; 93 94 int (*insn_config)(struct comedi_device *dev, 95 struct comedi_subdevice *s, 96 struct comedi_insn *insn, unsigned int *data); 97 }; 98 99 unsigned int comedi_8254_status(struct comedi_8254 *i8254, 100 unsigned int counter); 101 unsigned int comedi_8254_read(struct comedi_8254 *i8254, unsigned int counter); 102 void comedi_8254_write(struct comedi_8254 *i8254, 103 unsigned int counter, unsigned int val); 104 105 int comedi_8254_set_mode(struct comedi_8254 *i8254, 106 unsigned int counter, unsigned int mode); 107 int comedi_8254_load(struct comedi_8254 *i8254, 108 unsigned int counter, unsigned int val, unsigned int mode); 109 110 void comedi_8254_pacer_enable(struct comedi_8254 *i8254, 111 unsigned int counter1, unsigned int counter2, 112 bool enable); 113 void comedi_8254_update_divisors(struct comedi_8254 *i8254); 114 void comedi_8254_cascade_ns_to_timer(struct comedi_8254 *i8254, 115 unsigned int *nanosec, unsigned int flags); 116 void comedi_8254_ns_to_timer(struct comedi_8254 *i8254, 117 unsigned int *nanosec, unsigned int flags); 118 119 void comedi_8254_set_busy(struct comedi_8254 *i8254, 120 unsigned int counter, bool busy); 121 122 void comedi_8254_subdevice_init(struct comedi_subdevice *s, 123 struct comedi_8254 *i8254); 124 125 struct comedi_8254 *comedi_8254_init(unsigned long iobase, 126 unsigned int osc_base, 127 unsigned int iosize, 128 unsigned int regshift); 129 struct comedi_8254 *comedi_8254_mm_init(void __iomem *mmio, 130 unsigned int osc_base, 131 unsigned int iosize, 132 unsigned int regshift); 133 134 #endif /* _COMEDI_8254_H */ 135