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 | #include <linux/errno.h> |
16 | #include <linux/err.h> |
17 | |
18 | struct comedi_device; |
19 | struct comedi_insn; |
20 | struct comedi_subdevice; |
21 | |
22 | /* |
23 | * Common oscillator base values in nanoseconds |
24 | */ |
25 | #define I8254_OSC_BASE_10MHZ 100 |
26 | #define I8254_OSC_BASE_5MHZ 200 |
27 | #define I8254_OSC_BASE_4MHZ 250 |
28 | #define I8254_OSC_BASE_2MHZ 500 |
29 | #define I8254_OSC_BASE_1MHZ 1000 |
30 | #define I8254_OSC_BASE_100KHZ 10000 |
31 | #define I8254_OSC_BASE_10KHZ 100000 |
32 | #define I8254_OSC_BASE_1KHZ 1000000 |
33 | |
34 | /* |
35 | * I/O access size used to read/write registers |
36 | */ |
37 | #define I8254_IO8 1 |
38 | #define I8254_IO16 2 |
39 | #define I8254_IO32 4 |
40 | |
41 | /* |
42 | * Register map for generic 8254 timer (I8254_IO8 with 0 regshift) |
43 | */ |
44 | #define I8254_COUNTER0_REG 0x00 |
45 | #define I8254_COUNTER1_REG 0x01 |
46 | #define I8254_COUNTER2_REG 0x02 |
47 | #define I8254_CTRL_REG 0x03 |
48 | #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 0x10000 |
61 | |
62 | struct comedi_8254; |
63 | |
64 | /** |
65 | * typedef comedi_8254_iocb_fn - call-back function type for 8254 register access |
66 | * @i8254: pointer to struct comedi_8254 |
67 | * @dir: direction (0 = read, 1 = write) |
68 | * @reg: register number |
69 | * @val: value to write |
70 | * |
71 | * Return: Register value when reading, 0 when writing. |
72 | */ |
73 | typedef 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 module |
78 | * @iocb: I/O call-back function for register access |
79 | * @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 shift |
82 | * @osc_base: cascaded oscillator speed in ns |
83 | * @divisor: divisor for single counter |
84 | * @divisor1: divisor loaded into first cascaded counter |
85 | * @divisor2: divisor loaded into second cascaded counter |
86 | * #next_div: next divisor for single counter |
87 | * @next_div1: next divisor to use for first cascaded counter |
88 | * @next_div2: next divisor to use for second cascaded counter |
89 | * @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) callback |
93 | */ |
94 | struct 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 | |
115 | unsigned int comedi_8254_status(struct comedi_8254 *i8254, |
116 | unsigned int counter); |
117 | unsigned int comedi_8254_read(struct comedi_8254 *i8254, unsigned int counter); |
118 | void comedi_8254_write(struct comedi_8254 *i8254, |
119 | unsigned int counter, unsigned int val); |
120 | |
121 | int comedi_8254_set_mode(struct comedi_8254 *i8254, |
122 | unsigned int counter, unsigned int mode); |
123 | int comedi_8254_load(struct comedi_8254 *i8254, |
124 | unsigned int counter, unsigned int val, unsigned int mode); |
125 | |
126 | void comedi_8254_pacer_enable(struct comedi_8254 *i8254, |
127 | unsigned int counter1, unsigned int counter2, |
128 | bool enable); |
129 | void comedi_8254_update_divisors(struct comedi_8254 *i8254); |
130 | void comedi_8254_cascade_ns_to_timer(struct comedi_8254 *i8254, |
131 | unsigned int *nanosec, unsigned int flags); |
132 | void comedi_8254_ns_to_timer(struct comedi_8254 *i8254, |
133 | unsigned int *nanosec, unsigned int flags); |
134 | |
135 | void comedi_8254_set_busy(struct comedi_8254 *i8254, |
136 | unsigned int counter, bool busy); |
137 | |
138 | void comedi_8254_subdevice_init(struct comedi_subdevice *s, |
139 | struct comedi_8254 *i8254); |
140 | |
141 | #ifdef CONFIG_HAS_IOPORT |
142 | struct comedi_8254 *comedi_8254_io_alloc(unsigned long iobase, |
143 | unsigned int osc_base, |
144 | unsigned int iosize, |
145 | unsigned int regshift); |
146 | #else |
147 | static 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 | #endif |
155 | |
156 | struct 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 | |