3 * Generic 8254 timer/counter support
4 * Copyright (C) 2014 H Hartley Sweeten <hsweeten@visionengravers.com>
6 * COMEDI - Linux Control and Measurement Device Interface
7 * Copyright (C) 2000 David A. Schleef <ds@schleef.org>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
20 #ifndef _COMEDI_8254_H
21 #define _COMEDI_8254_H
24 * Common oscillator base values in nanoseconds
26 #define I8254_OSC_BASE_10MHZ 100
27 #define I8254_OSC_BASE_5MHZ 200
28 #define I8254_OSC_BASE_4MHZ 250
29 #define I8254_OSC_BASE_2MHZ 500
30 #define I8254_OSC_BASE_1MHZ 1000
31 #define I8254_OSC_BASE_100KHZ 10000
32 #define I8254_OSC_BASE_10KHZ 100000
33 #define I8254_OSC_BASE_1KHZ 1000000
36 * I/O access size used to read/write registers
43 * Register map for generic 8254 timer (I8254_IO8 with 0 regshift)
45 #define I8254_COUNTER0_REG 0x00
46 #define I8254_COUNTER1_REG 0x01
47 #define I8254_COUNTER2_REG 0x02
48 #define I8254_CTRL_REG 0x03
49 #define I8254_CTRL_SEL_CTR(x) ((x) << 6)
50 #define I8254_CTRL_READBACK_COUNT ((3 << 6) | (1 << 4))
51 #define I8254_CTRL_READBACK_STATUS ((3 << 6) | (1 << 5))
52 #define I8254_CTRL_READBACK_SEL_CTR(x) (2 << (x))
53 #define I8254_CTRL_LATCH (0 << 4)
54 #define I8254_CTRL_LSB_ONLY (1 << 4)
55 #define I8254_CTRL_MSB_ONLY (2 << 4)
56 #define I8254_CTRL_LSB_MSB (3 << 4)
58 /* counter maps zero to 0x10000 */
59 #define I8254_MAX_COUNT 0x10000
62 * struct comedi_8254 - private data used by this module
63 * @iobase: PIO base address of the registers (in/out)
64 * @mmio: MMIO base address of the registers (read/write)
65 * @iosize: I/O size used to access the registers (b/w/l)
66 * @regshift: register gap shift
67 * @osc_base: cascaded oscillator speed in ns
68 * @divisor: divisor for single counter
69 * @divisor1: divisor loaded into first cascaded counter
70 * @divisor2: divisor loaded into second cascaded counter
71 * #next_div: next divisor for single counter
72 * @next_div1: next divisor to use for first cascaded counter
73 * @next_div2: next divisor to use for second cascaded counter
74 * @clock_src; current clock source for each counter (driver specific)
75 * @gate_src; current gate source for each counter (driver specific)
76 * @busy: flags used to indicate that a counter is "busy"
77 * @insn_config: driver specific (*insn_config) callback
83 unsigned int regshift;
84 unsigned int osc_base;
86 unsigned int divisor1;
87 unsigned int divisor2;
88 unsigned int next_div;
89 unsigned int next_div1;
90 unsigned int next_div2;
91 unsigned int clock_src[3];
92 unsigned int gate_src[3];
95 int (*insn_config)(struct comedi_device *, struct comedi_subdevice *s,
96 struct comedi_insn *, unsigned int *data);
99 unsigned int comedi_8254_status(struct comedi_8254 *, unsigned int counter);
100 unsigned int comedi_8254_read(struct comedi_8254 *, unsigned int counter);
101 void comedi_8254_write(struct comedi_8254 *,
102 unsigned int counter, unsigned int val);
104 int comedi_8254_set_mode(struct comedi_8254 *,
105 unsigned int counter, unsigned int mode);
106 int comedi_8254_load(struct comedi_8254 *,
107 unsigned int counter, unsigned int val, unsigned int mode);
109 void comedi_8254_pacer_enable(struct comedi_8254 *,
110 unsigned int counter1, unsigned int counter2,
112 void comedi_8254_update_divisors(struct comedi_8254 *);
113 void comedi_8254_cascade_ns_to_timer(struct comedi_8254 *,
114 unsigned int *nanosec, unsigned int flags);
115 void comedi_8254_ns_to_timer(struct comedi_8254 *,
116 unsigned int *nanosec, unsigned int flags);
118 void comedi_8254_set_busy(struct comedi_8254 *,
119 unsigned int counter, bool busy);
121 void comedi_8254_subdevice_init(struct comedi_subdevice *,
122 struct comedi_8254 *);
124 struct comedi_8254 *comedi_8254_init(unsigned long iobase,
125 unsigned int osc_base,
127 unsigned int regshift);
128 struct comedi_8254 *comedi_8254_mm_init(void __iomem *mmio,
129 unsigned int osc_base,
131 unsigned int regshift);
133 #endif /* _COMEDI_8254_H */