/* SPDX-License-Identifier: GPL-2.0+ */ /* * comedi_8254.h * Generic 8254 timer/counter support * Copyright (C) 2014 H Hartley Sweeten * * COMEDI - Linux Control and Measurement Device Interface * Copyright (C) 2000 David A. Schleef */ #ifndef _COMEDI_8254_H #define _COMEDI_8254_H #include #include #include 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 */