Now that SiFive clock driver is merged in upstream Linux, we sync-up WRPLL library used by SiFive clock driver with upstream Linux sources.
Signed-off-by: Anup Patel anup.patel@wdc.com --- drivers/clk/analogbits/wrpll-cln28hpc.c | 165 ++++++++---------- drivers/clk/sifive/fu540-prci.c | 26 +-- include/linux/clk/analogbits-wrpll-cln28hpc.h | 70 +++----- 3 files changed, 107 insertions(+), 154 deletions(-)
diff --git a/drivers/clk/analogbits/wrpll-cln28hpc.c b/drivers/clk/analogbits/wrpll-cln28hpc.c index 68eb1148b9..776ead319a 100644 --- a/drivers/clk/analogbits/wrpll-cln28hpc.c +++ b/drivers/clk/analogbits/wrpll-cln28hpc.c @@ -1,20 +1,9 @@ // SPDX-License-Identifier: GPL-2.0 /* - * Copyright (c) 2019 Western Digital Corporation or its affiliates. - * - * Copyright (C) 2018 SiFive, Inc. + * Copyright (C) 2018-2019 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. - * * This library supports configuration parsing and reprogramming of * the CLN28HPC variant of the Analog Bits Wide Range PLL. The * intention is for this library to be reusable for any device that @@ -29,6 +18,7 @@ * References: * - Analog Bits "Wide Range PLL Datasheet", version 2015.10.01 * - SiFive FU540-C000 Manual v1p0, Chapter 7 "Clocking and Reset" + * https://static.dev.sifive.com/FU540-C000-v1.0.pdf */
#include <linux/bug.h> @@ -84,40 +74,38 @@ * range selection. * * Return: The RANGE value to be presented to the PLL configuration inputs, - * or -1 upon error. + * or a negative return code upon error. */ static int __wrpll_calc_filter_range(unsigned long post_divr_freq) { - u8 range; - if (post_divr_freq < MIN_POST_DIVR_FREQ || post_divr_freq > MAX_POST_DIVR_FREQ) { WARN(1, "%s: post-divider reference freq out of range: %lu", __func__, post_divr_freq); - return -1; + return -ERANGE; }
- if (post_divr_freq < 11000000) - range = 1; - else if (post_divr_freq < 18000000) - range = 2; - else if (post_divr_freq < 30000000) - range = 3; - else if (post_divr_freq < 50000000) - range = 4; - else if (post_divr_freq < 80000000) - range = 5; - else if (post_divr_freq < 130000000) - range = 6; - else - range = 7; - - return range; + switch (post_divr_freq) { + case 0 ... 10999999: + return 1; + case 11000000 ... 17999999: + return 2; + case 18000000 ... 29999999: + return 3; + case 30000000 ... 49999999: + return 4; + case 50000000 ... 79999999: + return 5; + case 80000000 ... 129999999: + return 6; + } + + return 7; }
/** * __wrpll_calc_fbdiv() - return feedback fixed divide value - * @c: ptr to a struct analogbits_wrpll_cfg record to read from + * @c: ptr to a struct wrpll_cfg record to read from * * The internal feedback path includes a fixed by-two divider; the * external feedback path does not. Return the appropriate divider @@ -132,7 +120,7 @@ static int __wrpll_calc_filter_range(unsigned long post_divr_freq) * Return: 2 if internal feedback is enabled or 1 if external feedback * is enabled. */ -static u8 __wrpll_calc_fbdiv(struct analogbits_wrpll_cfg *c) +static u8 __wrpll_calc_fbdiv(const struct wrpll_cfg *c) { return (c->flags & WRPLL_FLAGS_INT_FEEDBACK_MASK) ? 2 : 1; } @@ -172,7 +160,7 @@ static u8 __wrpll_calc_divq(u32 target_rate, u64 *vco_rate) *vco_rate = MIN_VCO_FREQ; } else { divq = ilog2(s); - *vco_rate = target_rate << divq; + *vco_rate = (u64)target_rate << divq; }
wcd_out: @@ -181,7 +169,7 @@ wcd_out:
/** * __wrpll_update_parent_rate() - update PLL data when parent rate changes - * @c: ptr to a struct analogbits_wrpll_cfg record to write PLL data to + * @c: ptr to a struct wrpll_cfg record to write PLL data to * @parent_rate: PLL input refclk rate (pre-R-divider) * * Pre-compute some data used by the PLL configuration algorithm when @@ -189,46 +177,40 @@ wcd_out: * computation when the parent rate remains constant - expected to be * the common case. * - * Returns: 0 upon success or -1 if the reference clock rate is out of range. + * Returns: 0 upon success or -ERANGE if the reference clock rate is + * out of range. */ -static int __wrpll_update_parent_rate(struct analogbits_wrpll_cfg *c, +static int __wrpll_update_parent_rate(struct wrpll_cfg *c, unsigned long parent_rate) { u8 max_r_for_parent;
if (parent_rate > MAX_INPUT_FREQ || parent_rate < MIN_POST_DIVR_FREQ) - return -1; + return -ERANGE;
- c->_parent_rate = parent_rate; + c->parent_rate = parent_rate; max_r_for_parent = div_u64(parent_rate, MIN_POST_DIVR_FREQ); - c->_max_r = min_t(u8, MAX_DIVR_DIVISOR, max_r_for_parent); + c->max_r = min_t(u8, MAX_DIVR_DIVISOR, max_r_for_parent);
- /* Round up */ - c->_init_r = div_u64(parent_rate + MAX_POST_DIVR_FREQ - 1, - MAX_POST_DIVR_FREQ); + c->init_r = DIV_ROUND_UP_ULL(parent_rate, MAX_POST_DIVR_FREQ);
return 0; }
-/* - * Public functions - */ - /** - * analogbits_wrpll_configure() - compute PLL configuration for a target rate - * @c: ptr to a struct analogbits_wrpll_cfg record to write into + * wrpll_configure() - compute PLL configuration for a target rate + * @c: ptr to a struct wrpll_cfg record to write into * @target_rate: target PLL output clock rate (post-Q-divider) * @parent_rate: PLL input refclk rate (pre-R-divider) * - * Given a pointer to a PLL context @c, a desired PLL target output - * rate @target_rate, and a reference clock input rate @parent_rate, - * compute the appropriate PLL signal configuration values. PLL - * reprogramming is not glitchless, so the caller should switch any - * downstream logic to a different clock source or clock-gate it - * before presenting these values to the PLL configuration signals. + * Compute the appropriate PLL signal configuration values and store + * in PLL context @c. PLL reprogramming is not glitchless, so the + * caller should switch any downstream logic to a different clock + * source or clock-gate it before presenting these values to the PLL + * configuration signals. * * The caller must pass this function a pre-initialized struct - * analogbits_wrpll_cfg record: either initialized to zero (with the + * wrpll_cfg record: either initialized to zero (with the * exception of the .name and .flags fields) or read from the PLL. * * Context: Any context. Caller must protect the memory pointed to by @c @@ -236,41 +218,26 @@ static int __wrpll_update_parent_rate(struct analogbits_wrpll_cfg *c, * * Return: 0 upon success; anything else upon failure. */ -int analogbits_wrpll_configure_for_rate(struct analogbits_wrpll_cfg *c, - u32 target_rate, - unsigned long parent_rate) +int wrpll_configure_for_rate(struct wrpll_cfg *c, u32 target_rate, + unsigned long parent_rate) { unsigned long ratio; u64 target_vco_rate, delta, best_delta, f_pre_div, vco, vco_pre; - u32 best_f, f, post_divr_freq, fbcfg; + u32 best_f, f, post_divr_freq; u8 fbdiv, divq, best_r, r; - - if (!c) - return -1; + int range;
if (c->flags == 0) { WARN(1, "%s called with uninitialized PLL config", __func__); - return -1; - } - - fbcfg = WRPLL_FLAGS_INT_FEEDBACK_MASK | WRPLL_FLAGS_EXT_FEEDBACK_MASK; - if ((c->flags & fbcfg) == fbcfg) { - WARN(1, "%s called with invalid PLL config", __func__); - return -1; - } - - if (c->flags == WRPLL_FLAGS_EXT_FEEDBACK_MASK) { - WARN(1, "%s: external feedback mode not currently supported", - __func__); - return -1; + return -EINVAL; }
/* Initialize rounding data if it hasn't been initialized already */ - if (parent_rate != c->_parent_rate) { + if (parent_rate != c->parent_rate) { if (__wrpll_update_parent_rate(c, parent_rate)) { pr_err("%s: PLL input rate is out of range\n", __func__); - return -1; + return -ERANGE; } }
@@ -281,11 +248,12 @@ int analogbits_wrpll_configure_for_rate(struct analogbits_wrpll_cfg *c, c->flags |= WRPLL_FLAGS_BYPASS_MASK; return 0; } + c->flags &= ~WRPLL_FLAGS_BYPASS_MASK;
/* Calculate the Q shift and target VCO rate */ divq = __wrpll_calc_divq(target_rate, &target_vco_rate); - if (divq == 0) + if (!divq) return -1; c->divq = divq;
@@ -301,8 +269,7 @@ int analogbits_wrpll_configure_for_rate(struct analogbits_wrpll_cfg *c, * Consider all values for R which land within * [MIN_POST_DIVR_FREQ, MAX_POST_DIVR_FREQ]; prefer smaller R */ - for (r = c->_init_r; r <= c->_max_r; ++r) { - /* What is the best F we can pick in this case? */ + for (r = c->init_r; r <= c->max_r; ++r) { f_pre_div = ratio * r; f = (f_pre_div + (1 << ROUND_SHIFT)) >> ROUND_SHIFT; f >>= (fbdiv - 1); @@ -334,46 +301,54 @@ int analogbits_wrpll_configure_for_rate(struct analogbits_wrpll_cfg *c, post_divr_freq = div_u64(parent_rate, best_r);
/* Pick the best PLL jitter filter */ - c->range = __wrpll_calc_filter_range(post_divr_freq); + range = __wrpll_calc_filter_range(post_divr_freq); + if (range < 0) + return range; + c->range = range;
return 0; }
/** - * analogbits_wrpll_calc_output_rate() - calculate the PLL's target output rate - * @c: ptr to a struct analogbits_wrpll_cfg record to read from + * wrpll_calc_output_rate() - calculate the PLL's target output rate + * @c: ptr to a struct wrpll_cfg record to read from * @parent_rate: PLL refclk rate * * Given a pointer to the PLL's current input configuration @c and the * PLL's input reference clock rate @parent_rate (before the R * pre-divider), calculate the PLL's output clock rate (after the Q - * post-divider) + * post-divider). * * Context: Any context. Caller must protect the memory pointed to by @c * from simultaneous modification. * - * Return: the PLL's output clock rate, in Hz. + * Return: the PLL's output clock rate, in Hz. The return value from + * this function is intended to be convenient to pass directly + * to the Linux clock framework; thus there is no explicit + * error return value. */ -unsigned long analogbits_wrpll_calc_output_rate(struct analogbits_wrpll_cfg *c, - unsigned long parent_rate) +unsigned long wrpll_calc_output_rate(const struct wrpll_cfg *c, + unsigned long parent_rate) { u8 fbdiv; u64 n;
- WARN(c->flags & WRPLL_FLAGS_EXT_FEEDBACK_MASK, - "external feedback mode not yet supported"); + if (c->flags & WRPLL_FLAGS_EXT_FEEDBACK_MASK) { + WARN(1, "external feedback mode not yet supported"); + return ULONG_MAX; + }
fbdiv = __wrpll_calc_fbdiv(c); n = parent_rate * fbdiv * (c->divf + 1); - n = div_u64(n, (c->divr + 1)); + n = div_u64(n, c->divr + 1); n >>= c->divq;
return n; }
/** - * analogbits_wrpll_calc_max_lock_us() - return the time for the PLL to lock - * @c: ptr to a struct analogbits_wrpll_cfg record to read from + * wrpll_calc_max_lock_us() - return the time for the PLL to lock + * @c: ptr to a struct wrpll_cfg record to read from * * Return the minimum amount of time (in microseconds) that the caller * must wait after reprogramming the PLL to ensure that it is locked @@ -383,7 +358,7 @@ unsigned long analogbits_wrpll_calc_output_rate(struct analogbits_wrpll_cfg *c, * Return: the minimum amount of time the caller must wait for the PLL * to lock (in microseconds) */ -unsigned int analogbits_wrpll_calc_max_lock_us(struct analogbits_wrpll_cfg *c) +unsigned int wrpll_calc_max_lock_us(const struct wrpll_cfg *c) { return MAX_LOCK_US; } diff --git a/drivers/clk/sifive/fu540-prci.c b/drivers/clk/sifive/fu540-prci.c index 56084db2e6..cdbf35e871 100644 --- a/drivers/clk/sifive/fu540-prci.c +++ b/drivers/clk/sifive/fu540-prci.c @@ -174,7 +174,7 @@ struct __prci_data { * bypass mux is not glitchless. */ struct __prci_wrpll_data { - struct analogbits_wrpll_cfg c; + struct wrpll_cfg c; void (*bypass)(struct __prci_data *pd); void (*no_bypass)(struct __prci_data *pd); u8 cfg0_offs; @@ -244,7 +244,7 @@ static void __prci_writel(u32 v, u32 offs, struct __prci_data *pd)
/** * __prci_wrpll_unpack() - unpack WRPLL configuration registers into parameters - * @c: ptr to a struct analogbits_wrpll_cfg record to write config into + * @c: ptr to a struct wrpll_cfg record to write config into * @r: value read from the PRCI PLL configuration register * * Given a value @r read from an FU540 PRCI PLL configuration register, @@ -256,7 +256,7 @@ static void __prci_writel(u32 v, u32 offs, struct __prci_data *pd) * * Context: Any context. */ -static void __prci_wrpll_unpack(struct analogbits_wrpll_cfg *c, u32 r) +static void __prci_wrpll_unpack(struct wrpll_cfg *c, u32 r) { u32 v;
@@ -287,7 +287,7 @@ static void __prci_wrpll_unpack(struct analogbits_wrpll_cfg *c, u32 r)
/** * __prci_wrpll_pack() - pack PLL configuration parameters into a register value - * @c: pointer to a struct analogbits_wrpll_cfg record containing the PLL's cfg + * @c: pointer to a struct wrpll_cfg record containing the PLL's cfg * * Using a set of WRPLL configuration values pointed to by @c, * assemble a PRCI PLL configuration register value, and return it to @@ -300,7 +300,7 @@ static void __prci_wrpll_unpack(struct analogbits_wrpll_cfg *c, u32 r) * Returns: a value suitable for writing into a PRCI PLL configuration * register */ -static u32 __prci_wrpll_pack(struct analogbits_wrpll_cfg *c) +static u32 __prci_wrpll_pack(struct wrpll_cfg *c) { u32 r = 0;
@@ -348,11 +348,11 @@ static void __prci_wrpll_read_cfg(struct __prci_data *pd, */ static void __prci_wrpll_write_cfg(struct __prci_data *pd, struct __prci_wrpll_data *pwd, - struct analogbits_wrpll_cfg *c) + struct wrpll_cfg *c) { __prci_writel(__prci_wrpll_pack(c), pwd->cfg0_offs, pd);
- memcpy(&pwd->c, c, sizeof(struct analogbits_wrpll_cfg)); + memcpy(&pwd->c, c, sizeof(struct wrpll_cfg)); }
/* Core clock mux control */ @@ -403,7 +403,7 @@ static unsigned long sifive_fu540_prci_wrpll_recalc_rate( { struct __prci_wrpll_data *pwd = pc->pwd;
- return analogbits_wrpll_calc_output_rate(&pwd->c, parent_rate); + return wrpll_calc_output_rate(&pwd->c, parent_rate); }
static unsigned long sifive_fu540_prci_wrpll_round_rate( @@ -412,13 +412,13 @@ static unsigned long sifive_fu540_prci_wrpll_round_rate( unsigned long *parent_rate) { struct __prci_wrpll_data *pwd = pc->pwd; - struct analogbits_wrpll_cfg c; + struct wrpll_cfg c;
memcpy(&c, &pwd->c, sizeof(c));
- analogbits_wrpll_configure_for_rate(&c, rate, *parent_rate); + wrpll_configure_for_rate(&c, rate, *parent_rate);
- return analogbits_wrpll_calc_output_rate(&c, *parent_rate); + return wrpll_calc_output_rate(&c, *parent_rate); }
static int sifive_fu540_prci_wrpll_set_rate(struct __prci_clock *pc, @@ -429,7 +429,7 @@ static int sifive_fu540_prci_wrpll_set_rate(struct __prci_clock *pc, struct __prci_data *pd = pc->pd; int r;
- r = analogbits_wrpll_configure_for_rate(&pwd->c, rate, parent_rate); + r = wrpll_configure_for_rate(&pwd->c, rate, parent_rate); if (r) return -ERANGE;
@@ -438,7 +438,7 @@ static int sifive_fu540_prci_wrpll_set_rate(struct __prci_clock *pc,
__prci_wrpll_write_cfg(pd, pwd, &pwd->c);
- udelay(analogbits_wrpll_calc_max_lock_us(&pwd->c)); + udelay(wrpll_calc_max_lock_us(&pwd->c));
if (pwd->no_bypass) pwd->no_bypass(pd); diff --git a/include/linux/clk/analogbits-wrpll-cln28hpc.h b/include/linux/clk/analogbits-wrpll-cln28hpc.h index 4432e24749..03279097e1 100644 --- a/include/linux/clk/analogbits-wrpll-cln28hpc.h +++ b/include/linux/clk/analogbits-wrpll-cln28hpc.h @@ -1,19 +1,8 @@ /* SPDX-License-Identifier: GPL-2.0 */ /* - * Copyright (c) 2019 Western Digital Corporation or its affiliates. - * - * Copyright (C) 2018 SiFive, Inc. + * Copyright (C) 2018-2019 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 @@ -25,7 +14,7 @@ #define DIVQ_VALUES 6
/* - * Bit definitions for struct analogbits_wrpll_cfg.flags + * 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 @@ -34,10 +23,6 @@ * 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) @@ -49,53 +34,46 @@ #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 + * 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 analogbits_wrpll_cfg record, the + * 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. - * - * Field names beginning with an underscore should be considered - * private to the wrpll-cln28hpc.c code. */ -struct analogbits_wrpll_cfg { +struct 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; +/* private: */ + 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); +int wrpll_configure_for_rate(struct wrpll_cfg *c, u32 target_rate, + unsigned long parent_rate);
-unsigned int analogbits_wrpll_calc_max_lock_us(struct analogbits_wrpll_cfg *c); +unsigned int wrpll_calc_max_lock_us(const struct wrpll_cfg *c);
-unsigned long analogbits_wrpll_calc_output_rate(struct analogbits_wrpll_cfg *c, - unsigned long parent_rate); +unsigned long wrpll_calc_output_rate(const struct wrpll_cfg *c, + unsigned long parent_rate);
#endif /* __LINUX_CLK_ANALOGBITS_WRPLL_CLN28HPC_H */