diff options
Diffstat (limited to 'include/linux/clk/analogbits-wrpll-cln28hpc.h')
| -rw-r--r-- | include/linux/clk/analogbits-wrpll-cln28hpc.h | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/include/linux/clk/analogbits-wrpll-cln28hpc.h b/include/linux/clk/analogbits-wrpll-cln28hpc.h new file mode 100644 index 000000000000..03279097e138 --- /dev/null +++ b/include/linux/clk/analogbits-wrpll-cln28hpc.h @@ -0,0 +1,79 @@ +/* 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 */ |