u-boot/include/linux/clk/analogbits-wrpll-cln28hpc.h
Anup Patel d04c79d2b2 clk: sifive: Factor-out PLL library as separate module
To match SiFive clock driver with latest Linux, we factor-out PLL
library as separate module under drivers/clk/analogbits.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2019-07-19 14:24:51 +08:00

101 lines
3.7 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (c) 2019 Western Digital Corporation or its affiliates.
*
* Copyright (C) 2018 SiFive, Inc.
* Wesley Terpstra
* Paul Walmsley
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#ifndef __LINUX_CLK_ANALOGBITS_WRPLL_CLN28HPC_H
#define __LINUX_CLK_ANALOGBITS_WRPLL_CLN28HPC_H
#include <linux/types.h>
/* DIVQ_VALUES: number of valid DIVQ values */
#define DIVQ_VALUES 6
/*
* Bit definitions for struct analogbits_wrpll_cfg.flags
*
* WRPLL_FLAGS_BYPASS_FLAG: if set, the PLL is either in bypass, or should be
* programmed to enter bypass
* WRPLL_FLAGS_RESET_FLAG: if set, the PLL is in reset
* WRPLL_FLAGS_INT_FEEDBACK_FLAG: if set, the PLL is configured for internal
* feedback mode
* WRPLL_FLAGS_EXT_FEEDBACK_FLAG: if set, the PLL is configured for external
* feedback mode (not yet supported by this driver)
*
* The flags WRPLL_FLAGS_INT_FEEDBACK_FLAG and WRPLL_FLAGS_EXT_FEEDBACK_FLAG are
* mutually exclusive. If both bits are set, or both are zero, the struct
* analogbits_wrpll_cfg record is uninitialized or corrupt.
*/
#define WRPLL_FLAGS_BYPASS_SHIFT 0
#define WRPLL_FLAGS_BYPASS_MASK BIT(WRPLL_FLAGS_BYPASS_SHIFT)
#define WRPLL_FLAGS_RESET_SHIFT 1
#define WRPLL_FLAGS_RESET_MASK BIT(WRPLL_FLAGS_RESET_SHIFT)
#define WRPLL_FLAGS_INT_FEEDBACK_SHIFT 2
#define WRPLL_FLAGS_INT_FEEDBACK_MASK BIT(WRPLL_FLAGS_INT_FEEDBACK_SHIFT)
#define WRPLL_FLAGS_EXT_FEEDBACK_SHIFT 3
#define WRPLL_FLAGS_EXT_FEEDBACK_MASK BIT(WRPLL_FLAGS_EXT_FEEDBACK_SHIFT)
/**
* struct analogbits_wrpll_cfg - WRPLL configuration values
* @divr: reference divider value (6 bits), as presented to the PLL signals.
* @divf: feedback divider value (9 bits), as presented to the PLL signals.
* @divq: output divider value (3 bits), as presented to the PLL signals.
* @flags: PLL configuration flags. See above for more information.
* @range: PLL loop filter range. See below for more information.
* @_output_rate_cache: cached output rates, swept across DIVQ.
* @_parent_rate: PLL refclk rate for which values are valid
* @_max_r: maximum possible R divider value, given @parent_rate
* @_init_r: initial R divider value to start the search from
*
* @divr, @divq, @divq, @range represent what the PLL expects to see
* on its input signals. Thus @divr and @divf are the actual divisors
* minus one. @divq is a power-of-two divider; for example, 1 =
* divide-by-2 and 6 = divide-by-64. 0 is an invalid @divq value.
*
* When initially passing a struct analogbits_wrpll_cfg record, the
* record should be zero-initialized with the exception of the @flags
* field. The only flag bits that need to be set are either
* WRPLL_FLAGS_INT_FEEDBACK or WRPLL_FLAGS_EXT_FEEDBACK.
*
* Field names beginning with an underscore should be considered
* private to the wrpll-cln28hpc.c code.
*/
struct analogbits_wrpll_cfg {
u8 divr;
u8 divq;
u8 range;
u8 flags;
u16 divf;
u32 _output_rate_cache[DIVQ_VALUES];
unsigned long _parent_rate;
u8 _max_r;
u8 _init_r;
};
/*
* Function prototypes
*/
int analogbits_wrpll_configure_for_rate(struct analogbits_wrpll_cfg *c,
u32 target_rate,
unsigned long parent_rate);
unsigned int analogbits_wrpll_calc_max_lock_us(struct analogbits_wrpll_cfg *c);
unsigned long analogbits_wrpll_calc_output_rate(struct analogbits_wrpll_cfg *c,
unsigned long parent_rate);
#endif /* __LINUX_CLK_ANALOGBITS_WRPLL_CLN28HPC_H */