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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2018-2019 SiFive, Inc.
* Wesley Terpstra
* Paul Walmsley
*/
#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 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)
*/
#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 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 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.
*/
struct wrpll_cfg {
u8 divr;
u8 divq;
u8 range;
u8 flags;
u16 divf;
/* private: */
u32 output_rate_cache[DIVQ_VALUES];
unsigned long parent_rate;
u8 max_r;
u8 init_r;
};
int wrpll_configure_for_rate(struct wrpll_cfg *c, u32 target_rate,
unsigned long parent_rate);
unsigned int wrpll_calc_max_lock_us(const struct wrpll_cfg *c);
unsigned long wrpll_calc_output_rate(const struct wrpll_cfg *c,
unsigned long parent_rate);
#endif /* __LINUX_CLK_ANALOGBITS_WRPLL_CLN28HPC_H */
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