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u-boot/drivers/clk/clk_kendryte.c
Sean Anderson 425c08faa8 clk: k210: Try harder to get the best config 
In some cases, the best config cannot be used because the VCO would be
out-of-spec. In these cases, we may need to try a worse combination of r/od
in order to find the best representable config. This also adds a few test
cases to catch this and other (possible) unlikely errors.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2021-10-07 16:08:23 +08:00

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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2019-20 Sean Anderson <seanga2@gmail.com>
*/
#define LOG_CATEGORY UCLASS_CLK
#include <common.h>
#include <clk.h>
#include <clk-uclass.h>
#include <div64.h>
#include <dm.h>
#include <log.h>
#include <mapmem.h>
#include <serial.h>
#include <dt-bindings/clock/k210-sysctl.h>
#include <dt-bindings/mfd/k210-sysctl.h>
#include <kendryte/pll.h>
#include <linux/bitfield.h>
DECLARE_GLOBAL_DATA_PTR;
/**
* struct k210_clk_priv - K210 clock driver private data
* @base: The base address of the sysctl device
* @in0: The "in0" external oscillator
*/
struct k210_clk_priv {
void __iomem *base;
struct clk in0;
};
/*
* All parameters for different sub-clocks are collected into parameter arrays.
* These parameters are then initialized by the clock which uses them during
* probe. To save space, ids are automatically generated for each sub-clock by
* using an enum. Instead of storing a parameter struct for each clock, even for
* those clocks which don't use a particular type of sub-clock, we can just
* store the parameters for the clocks which need them.
*
* So why do it like this? Arranging all the sub-clocks together makes it very
* easy to find bugs in the code.
*/
/**
* enum k210_clk_div_type - The type of divider
* @K210_DIV_ONE: freq = parent / (reg + 1)
* @K210_DIV_EVEN: freq = parent / 2 / (reg + 1)
* @K210_DIV_POWER: freq = parent / (2 << reg)
* @K210_DIV_FIXED: freq = parent / factor
*/
enum k210_clk_div_type {
K210_DIV_ONE,
K210_DIV_EVEN,
K210_DIV_POWER,
K210_DIV_FIXED,
};
/**
* struct k210_div_params - Parameters for dividing clocks
* @type: An &enum k210_clk_div_type specifying the dividing formula
* @off: The offset of the divider from the sysctl base address
* @shift: The offset of the LSB of the divider
* @width: The number of bits in the divider
* @div: The fixed divisor for this divider
*/
struct k210_div_params {
u8 type;
union {
struct {
u8 off;
u8 shift;
u8 width;
};
u8 div;
};
};
#define DIV_LIST \
DIV(K210_CLK_ACLK, K210_SYSCTL_SEL0, 1, 2, K210_DIV_POWER) \
DIV(K210_CLK_APB0, K210_SYSCTL_SEL0, 3, 3, K210_DIV_ONE) \
DIV(K210_CLK_APB1, K210_SYSCTL_SEL0, 6, 3, K210_DIV_ONE) \
DIV(K210_CLK_APB2, K210_SYSCTL_SEL0, 9, 3, K210_DIV_ONE) \
DIV(K210_CLK_SRAM0, K210_SYSCTL_THR0, 0, 4, K210_DIV_ONE) \
DIV(K210_CLK_SRAM1, K210_SYSCTL_THR0, 4, 4, K210_DIV_ONE) \
DIV(K210_CLK_AI, K210_SYSCTL_THR0, 8, 4, K210_DIV_ONE) \
DIV(K210_CLK_DVP, K210_SYSCTL_THR0, 12, 4, K210_DIV_ONE) \
DIV(K210_CLK_ROM, K210_SYSCTL_THR0, 16, 4, K210_DIV_ONE) \
DIV(K210_CLK_SPI0, K210_SYSCTL_THR1, 0, 8, K210_DIV_EVEN) \
DIV(K210_CLK_SPI1, K210_SYSCTL_THR1, 8, 8, K210_DIV_EVEN) \
DIV(K210_CLK_SPI2, K210_SYSCTL_THR1, 16, 8, K210_DIV_EVEN) \
DIV(K210_CLK_SPI3, K210_SYSCTL_THR1, 24, 8, K210_DIV_EVEN) \
DIV(K210_CLK_TIMER0, K210_SYSCTL_THR2, 0, 8, K210_DIV_EVEN) \
DIV(K210_CLK_TIMER1, K210_SYSCTL_THR2, 8, 8, K210_DIV_EVEN) \
DIV(K210_CLK_TIMER2, K210_SYSCTL_THR2, 16, 8, K210_DIV_EVEN) \
DIV(K210_CLK_I2S0, K210_SYSCTL_THR3, 0, 16, K210_DIV_EVEN) \
DIV(K210_CLK_I2S1, K210_SYSCTL_THR3, 16, 16, K210_DIV_EVEN) \
DIV(K210_CLK_I2S2, K210_SYSCTL_THR4, 0, 16, K210_DIV_EVEN) \
DIV(K210_CLK_I2S0_M, K210_SYSCTL_THR4, 16, 8, K210_DIV_EVEN) \
DIV(K210_CLK_I2S1_M, K210_SYSCTL_THR4, 24, 8, K210_DIV_EVEN) \
DIV(K210_CLK_I2S2_M, K210_SYSCTL_THR4, 0, 8, K210_DIV_EVEN) \
DIV(K210_CLK_I2C0, K210_SYSCTL_THR5, 8, 8, K210_DIV_EVEN) \
DIV(K210_CLK_I2C1, K210_SYSCTL_THR5, 16, 8, K210_DIV_EVEN) \
DIV(K210_CLK_I2C2, K210_SYSCTL_THR5, 24, 8, K210_DIV_EVEN) \
DIV(K210_CLK_WDT0, K210_SYSCTL_THR6, 0, 8, K210_DIV_EVEN) \
DIV(K210_CLK_WDT1, K210_SYSCTL_THR6, 8, 8, K210_DIV_EVEN) \
DIV_FIXED(K210_CLK_CLINT, 50) \
#define _DIVIFY(id) K210_CLK_DIV_##id
#define DIVIFY(id) _DIVIFY(id)
enum k210_div_id {
#define DIV(id, ...) DIVIFY(id),
#define DIV_FIXED DIV
DIV_LIST
#undef DIV
#undef DIV_FIXED
K210_CLK_DIV_NONE,
};
static const struct k210_div_params k210_divs[] = {
#define DIV(id, _off, _shift, _width, _type) \
[DIVIFY(id)] = { \
.type = (_type), \
.off = (_off), \
.shift = (_shift), \
.width = (_width), \
},
#define DIV_FIXED(id, _div) \
[DIVIFY(id)] = { \
.type = K210_DIV_FIXED, \
.div = (_div) \
},
DIV_LIST
#undef DIV
#undef DIV_FIXED
};
#undef DIV
#undef DIV_LIST
/**
* struct k210_gate_params - Parameters for gated clocks
* @off: The offset of the gate from the sysctl base address
* @bit_idx: The index of the bit within the register
*/
struct k210_gate_params {
u8 off;
u8 bit_idx;
};
#define GATE_LIST \
GATE(K210_CLK_CPU, K210_SYSCTL_EN_CENT, 0) \
GATE(K210_CLK_SRAM0, K210_SYSCTL_EN_CENT, 1) \
GATE(K210_CLK_SRAM1, K210_SYSCTL_EN_CENT, 2) \
GATE(K210_CLK_APB0, K210_SYSCTL_EN_CENT, 3) \
GATE(K210_CLK_APB1, K210_SYSCTL_EN_CENT, 4) \
GATE(K210_CLK_APB2, K210_SYSCTL_EN_CENT, 5) \
GATE(K210_CLK_ROM, K210_SYSCTL_EN_PERI, 0) \
GATE(K210_CLK_DMA, K210_SYSCTL_EN_PERI, 1) \
GATE(K210_CLK_AI, K210_SYSCTL_EN_PERI, 2) \
GATE(K210_CLK_DVP, K210_SYSCTL_EN_PERI, 3) \
GATE(K210_CLK_FFT, K210_SYSCTL_EN_PERI, 4) \
GATE(K210_CLK_GPIO, K210_SYSCTL_EN_PERI, 5) \
GATE(K210_CLK_SPI0, K210_SYSCTL_EN_PERI, 6) \
GATE(K210_CLK_SPI1, K210_SYSCTL_EN_PERI, 7) \
GATE(K210_CLK_SPI2, K210_SYSCTL_EN_PERI, 8) \
GATE(K210_CLK_SPI3, K210_SYSCTL_EN_PERI, 9) \
GATE(K210_CLK_I2S0, K210_SYSCTL_EN_PERI, 10) \
GATE(K210_CLK_I2S1, K210_SYSCTL_EN_PERI, 11) \
GATE(K210_CLK_I2S2, K210_SYSCTL_EN_PERI, 12) \
GATE(K210_CLK_I2C0, K210_SYSCTL_EN_PERI, 13) \
GATE(K210_CLK_I2C1, K210_SYSCTL_EN_PERI, 14) \
GATE(K210_CLK_I2C2, K210_SYSCTL_EN_PERI, 15) \
GATE(K210_CLK_UART1, K210_SYSCTL_EN_PERI, 16) \
GATE(K210_CLK_UART2, K210_SYSCTL_EN_PERI, 17) \
GATE(K210_CLK_UART3, K210_SYSCTL_EN_PERI, 18) \
GATE(K210_CLK_AES, K210_SYSCTL_EN_PERI, 19) \
GATE(K210_CLK_FPIOA, K210_SYSCTL_EN_PERI, 20) \
GATE(K210_CLK_TIMER0, K210_SYSCTL_EN_PERI, 21) \
GATE(K210_CLK_TIMER1, K210_SYSCTL_EN_PERI, 22) \
GATE(K210_CLK_TIMER2, K210_SYSCTL_EN_PERI, 23) \
GATE(K210_CLK_WDT0, K210_SYSCTL_EN_PERI, 24) \
GATE(K210_CLK_WDT1, K210_SYSCTL_EN_PERI, 25) \
GATE(K210_CLK_SHA, K210_SYSCTL_EN_PERI, 26) \
GATE(K210_CLK_OTP, K210_SYSCTL_EN_PERI, 27) \
GATE(K210_CLK_RTC, K210_SYSCTL_EN_PERI, 29)
#define _GATEIFY(id) K210_CLK_GATE_##id
#define GATEIFY(id) _GATEIFY(id)
enum k210_gate_id {
#define GATE(id, ...) GATEIFY(id),
GATE_LIST
#undef GATE
K210_CLK_GATE_NONE,
};
static const struct k210_gate_params k210_gates[] = {
#define GATE(id, _off, _idx) \
[GATEIFY(id)] = { \
.off = (_off), \
.bit_idx = (_idx), \
},
GATE_LIST
#undef GATE
};
#undef GATE_LIST
/* The most parents is PLL2 */
#define K210_CLK_MAX_PARENTS 3
/**
* struct k210_mux_params - Parameters for muxed clocks
* @parents: A list of parent clock ids
* @num_parents: The number of parent clocks
* @off: The offset of the mux from the base sysctl address
* @shift: The offset of the LSB of the mux selector
* @width: The number of bits in the mux selector
*/
struct k210_mux_params {
u8 parents[K210_CLK_MAX_PARENTS];
u8 num_parents;
u8 off;
u8 shift;
u8 width;
};
#define MUX(id, reg, shift, width) \
MUX_PARENTS(id, reg, shift, width, K210_CLK_IN0, K210_CLK_PLL0)
#define MUX_LIST \
MUX_PARENTS(K210_CLK_PLL2, K210_SYSCTL_PLL2, 26, 2, \
K210_CLK_IN0, K210_CLK_PLL0, K210_CLK_PLL1) \
MUX(K210_CLK_ACLK, K210_SYSCTL_SEL0, 0, 1) \
MUX(K210_CLK_SPI3, K210_SYSCTL_SEL0, 12, 1) \
MUX(K210_CLK_TIMER0, K210_SYSCTL_SEL0, 13, 1) \
MUX(K210_CLK_TIMER1, K210_SYSCTL_SEL0, 14, 1) \
MUX(K210_CLK_TIMER2, K210_SYSCTL_SEL0, 15, 1)
#define _MUXIFY(id) K210_CLK_MUX_##id
#define MUXIFY(id) _MUXIFY(id)
enum k210_mux_id {
#define MUX_PARENTS(id, ...) MUXIFY(id),
MUX_LIST
#undef MUX_PARENTS
K210_CLK_MUX_NONE,
};
static const struct k210_mux_params k210_muxes[] = {
#define MUX_PARENTS(id, _off, _shift, _width, ...) \
[MUXIFY(id)] = { \
.parents = { __VA_ARGS__ }, \
.num_parents = __count_args(__VA_ARGS__), \
.off = (_off), \
.shift = (_shift), \
.width = (_width), \
},
MUX_LIST
#undef MUX_PARENTS
};
#undef MUX
#undef MUX_LIST
/**
* struct k210_pll_params - K210 PLL parameters
* @off: The offset of the PLL from the base sysctl address
* @shift: The offset of the LSB of the lock status
* @width: The number of bits in the lock status
*/
struct k210_pll_params {
u8 off;
u8 shift;
u8 width;
};
static const struct k210_pll_params k210_plls[] = {
#define PLL(_off, _shift, _width) { \
.off = (_off), \
.shift = (_shift), \
.width = (_width), \
}
[0] = PLL(K210_SYSCTL_PLL0, 0, 2),
[1] = PLL(K210_SYSCTL_PLL1, 8, 1),
[2] = PLL(K210_SYSCTL_PLL2, 16, 1),
#undef PLL
};
/**
* enum k210_clk_flags - The type of a K210 clock
* @K210_CLKF_MUX: This clock has a mux and not a static parent
* @K210_CLKF_PLL: This clock is a PLL
*/
enum k210_clk_flags {
K210_CLKF_MUX = BIT(0),
K210_CLKF_PLL = BIT(1),
};
/**
* struct k210_clk_params - The parameters defining a K210 clock
* @name: The name of the clock
* @flags: A set of &enum k210_clk_flags defining which fields are valid
* @mux: An &enum k210_mux_id of this clock's mux
* @parent: The clock id of this clock's parent
* @pll: The id of the PLL (if this clock is a PLL)
* @div: An &enum k210_div_id of this clock's divider
* @gate: An &enum k210_gate_id of this clock's gate
*/
struct k210_clk_params {
#if CONFIG_IS_ENABLED(CMD_CLK)
const char *name;
#endif
u8 flags;
union {
u8 parent;
u8 mux;
};
union {
u8 pll;
struct {
u8 div;
u8 gate;
};
};
};
static const struct k210_clk_params k210_clks[] = {
#if CONFIG_IS_ENABLED(CMD_CLK)
#define NAME(_name) .name = (_name),
#else
#define NAME(name)
#endif
#define CLK(id, _name, _parent, _div, _gate) \
[id] = { \
NAME(_name) \
.parent = (_parent), \
.div = (_div), \
.gate = (_gate), \
}
#define CLK_MUX(id, _name, _mux, _div, _gate) \
[id] = { \
NAME(_name) \
.flags = K210_CLKF_MUX, \
.mux = (_mux), \
.div = (_div), \
.gate = (_gate), \
}
#define CLK_PLL(id, _pll, _parent) \
[id] = { \
NAME("pll" #_pll) \
.flags = K210_CLKF_PLL, \
.parent = (_parent), \
.pll = (_pll), \
}
#define CLK_FULL(id, name) \
CLK_MUX(id, name, MUXIFY(id), DIVIFY(id), GATEIFY(id))
#define CLK_NOMUX(id, name, parent) \
CLK(id, name, parent, DIVIFY(id), GATEIFY(id))
#define CLK_DIV(id, name, parent) \
CLK(id, name, parent, DIVIFY(id), K210_CLK_GATE_NONE)
#define CLK_GATE(id, name, parent) \
CLK(id, name, parent, K210_CLK_DIV_NONE, GATEIFY(id))
CLK_PLL(K210_CLK_PLL0, 0, K210_CLK_IN0),
CLK_PLL(K210_CLK_PLL1, 1, K210_CLK_IN0),
[K210_CLK_PLL2] = {
NAME("pll2")
.flags = K210_CLKF_MUX | K210_CLKF_PLL,
.mux = MUXIFY(K210_CLK_PLL2),
.pll = 2,
},
CLK_MUX(K210_CLK_ACLK, "aclk", MUXIFY(K210_CLK_ACLK),
DIVIFY(K210_CLK_ACLK), K210_CLK_GATE_NONE),
CLK_FULL(K210_CLK_SPI3, "spi3"),
CLK_FULL(K210_CLK_TIMER0, "timer0"),
CLK_FULL(K210_CLK_TIMER1, "timer1"),
CLK_FULL(K210_CLK_TIMER2, "timer2"),
CLK_NOMUX(K210_CLK_SRAM0, "sram0", K210_CLK_ACLK),
CLK_NOMUX(K210_CLK_SRAM1, "sram1", K210_CLK_ACLK),
CLK_NOMUX(K210_CLK_ROM, "rom", K210_CLK_ACLK),
CLK_NOMUX(K210_CLK_DVP, "dvp", K210_CLK_ACLK),
CLK_NOMUX(K210_CLK_APB0, "apb0", K210_CLK_ACLK),
CLK_NOMUX(K210_CLK_APB1, "apb1", K210_CLK_ACLK),
CLK_NOMUX(K210_CLK_APB2, "apb2", K210_CLK_ACLK),
CLK_NOMUX(K210_CLK_AI, "ai", K210_CLK_PLL1),
CLK_NOMUX(K210_CLK_I2S0, "i2s0", K210_CLK_PLL2),
CLK_NOMUX(K210_CLK_I2S1, "i2s1", K210_CLK_PLL2),
CLK_NOMUX(K210_CLK_I2S2, "i2s2", K210_CLK_PLL2),
CLK_NOMUX(K210_CLK_WDT0, "wdt0", K210_CLK_IN0),
CLK_NOMUX(K210_CLK_WDT1, "wdt1", K210_CLK_IN0),
CLK_NOMUX(K210_CLK_SPI0, "spi0", K210_CLK_PLL0),
CLK_NOMUX(K210_CLK_SPI1, "spi1", K210_CLK_PLL0),
CLK_NOMUX(K210_CLK_SPI2, "spi2", K210_CLK_PLL0),
CLK_NOMUX(K210_CLK_I2C0, "i2c0", K210_CLK_PLL0),
CLK_NOMUX(K210_CLK_I2C1, "i2c1", K210_CLK_PLL0),
CLK_NOMUX(K210_CLK_I2C2, "i2c2", K210_CLK_PLL0),
CLK_DIV(K210_CLK_I2S0_M, "i2s0_m", K210_CLK_PLL2),
CLK_DIV(K210_CLK_I2S1_M, "i2s1_m", K210_CLK_PLL2),
CLK_DIV(K210_CLK_I2S2_M, "i2s2_m", K210_CLK_PLL2),
CLK_DIV(K210_CLK_CLINT, "clint", K210_CLK_ACLK),
CLK_GATE(K210_CLK_CPU, "cpu", K210_CLK_ACLK),
CLK_GATE(K210_CLK_DMA, "dma", K210_CLK_ACLK),
CLK_GATE(K210_CLK_FFT, "fft", K210_CLK_ACLK),
CLK_GATE(K210_CLK_GPIO, "gpio", K210_CLK_APB0),
CLK_GATE(K210_CLK_UART1, "uart1", K210_CLK_APB0),
CLK_GATE(K210_CLK_UART2, "uart2", K210_CLK_APB0),
CLK_GATE(K210_CLK_UART3, "uart3", K210_CLK_APB0),
CLK_GATE(K210_CLK_FPIOA, "fpioa", K210_CLK_APB0),
CLK_GATE(K210_CLK_SHA, "sha", K210_CLK_APB0),
CLK_GATE(K210_CLK_AES, "aes", K210_CLK_APB1),
CLK_GATE(K210_CLK_OTP, "otp", K210_CLK_APB1),
CLK_GATE(K210_CLK_RTC, "rtc", K210_CLK_IN0),
#undef NAME
#undef CLK_PLL
#undef CLK
#undef CLK_FULL
#undef CLK_NOMUX
#undef CLK_DIV
#undef CLK_GATE
#undef CLK_LIST
};
#define K210_PLL_CLKR GENMASK(3, 0)
#define K210_PLL_CLKF GENMASK(9, 4)
#define K210_PLL_CLKOD GENMASK(13, 10) /* Output Divider */
#define K210_PLL_BWADJ GENMASK(19, 14) /* BandWidth Adjust */
#define K210_PLL_RESET BIT(20)
#define K210_PLL_PWRD BIT(21) /* PoWeReD */
#define K210_PLL_INTFB BIT(22) /* Internal FeedBack */
#define K210_PLL_BYPASS BIT(23)
#define K210_PLL_TEST BIT(24)
#define K210_PLL_EN BIT(25)
#define K210_PLL_TEST_EN BIT(26)
#define K210_PLL_LOCK 0
#define K210_PLL_CLEAR_SLIP 2
#define K210_PLL_TEST_OUT 3
#ifdef CONFIG_CLK_K210_SET_RATE
static int k210_pll_enable(struct k210_clk_priv *priv, int id);
static int k210_pll_disable(struct k210_clk_priv *priv, int id);
static ulong k210_pll_get_rate(struct k210_clk_priv *priv, int id, ulong rate_in);
/*
* The PLL included with the Kendryte K210 appears to be a True Circuits, Inc.
* General-Purpose PLL. The logical layout of the PLL with internal feedback is
* approximately the following:
*
* +---------------+
* |reference clock|
* +---------------+
* |
* v
* +--+
* |/r|
* +--+
* |
* v
* +-------------+
* |divided clock|
* +-------------+
* |
* v
* +--------------+
* |phase detector|<---+
* +--------------+ |
* | |
* v +--------------+
* +---+ |feedback clock|
* |VCO| +--------------+
* +---+ ^
* | +--+ |
* +--->|/f|---+
* | +--+
* v
* +---+
* |/od|
* +---+
* |
* v
* +------+
* |output|
* +------+
*
* The k210 PLLs have three factors: r, f, and od. Because of the feedback mode,
* the effect of the division by f is to multiply the input frequency. The
* equation for the output rate is
* rate = (rate_in * f) / (r * od).
* Moving knowns to one side of the equation, we get
* rate / rate_in = f / (r * od)
* Rearranging slightly,
* abs_error = abs((rate / rate_in) - (f / (r * od))).
* To get relative, error, we divide by the expected ratio
* error = abs((rate / rate_in) - (f / (r * od))) / (rate / rate_in).
* Simplifying,
* error = abs(1 - f / (r * od)) / (rate / rate_in)
* error = abs(1 - (f * rate_in) / (r * od * rate))
* Using the constants ratio = rate / rate_in and inv_ratio = rate_in / rate,
* error = abs((f * inv_ratio) / (r * od) - 1)
* This is the error used in evaluating parameters.
*
* r and od are four bits each, while f is six bits. Because r and od are
* multiplied together, instead of the full 256 values possible if both bits
* were used fully, there are only 97 distinct products. Combined with f, there
* are 6208 theoretical settings for the PLL. However, most of these settings
* can be ruled out immediately because they do not have the correct ratio.
*
* In addition to the constraint of approximating the desired ratio, parameters
* must also keep internal pll frequencies within acceptable ranges. The divided
* clock's minimum and maximum frequencies have a ratio of around 128. This
* leaves fairly substantial room to work with, especially since the only
* affected parameter is r. The VCO's minimum and maximum frequency have a ratio
* of 5, which is considerably more restrictive.
*
* The r and od factors are stored in a table. This is to make it easy to find
* the next-largest product. Some products have multiple factorizations, but
* only when one factor has at least a 2.5x ratio to the factors of the other
* factorization. This is because any smaller ratio would not make a difference
* when ensuring the VCO's frequency is within spec.
*
* Throughout the calculation function, fixed point arithmetic is used. Because
* the range of rate and rate_in may be up to 1.75 GHz, or around 2^30, 64-bit
* 32.32 fixed-point numbers are used to represent ratios. In general, to
* implement division, the numerator is first multiplied by 2^32. This gives a
* result where the whole number part is in the upper 32 bits, and the fraction
* is in the lower 32 bits.
*
* In general, rounding is done to the closest integer. This helps find the best
* approximation for the ratio. Rounding in one direction (e.g down) could cause
* the function to miss a better ratio with one of the parameters increased by
* one.
*/
/*
* The factors table was generated with the following python code:
*
* def p(x, y):
* return (1.0*x/y > 2.5) or (1.0*y/x > 2.5)
*
* factors = {}
* for i in range(1, 17):
* for j in range(1, 17):
* fs = factors.get(i*j) or []
* if fs == [] or all([
* (p(i, x) and p(i, y)) or (p(j, x) and p(j, y))
* for (x, y) in fs]):
* fs.append((i, j))
* factors[i*j] = fs
*
* for k, l in sorted(factors.items()):
* for v in l:
* print("PACK(%s, %s)," % v)
*/
#define PACK(r, od) (((((r) - 1) & 0xF) << 4) | (((od) - 1) & 0xF))
#define UNPACK_R(val) ((((val) >> 4) & 0xF) + 1)
#define UNPACK_OD(val) (((val) & 0xF) + 1)
static const u8 factors[] = {
PACK(1, 1),
PACK(1, 2),
PACK(1, 3),
PACK(1, 4),
PACK(1, 5),
PACK(1, 6),
PACK(1, 7),
PACK(1, 8),
PACK(1, 9),
PACK(3, 3),
PACK(1, 10),
PACK(1, 11),
PACK(1, 12),
PACK(3, 4),
PACK(1, 13),
PACK(1, 14),
PACK(1, 15),
PACK(3, 5),
PACK(1, 16),
PACK(4, 4),
PACK(2, 9),
PACK(2, 10),
PACK(3, 7),
PACK(2, 11),
PACK(2, 12),
PACK(5, 5),
PACK(2, 13),
PACK(3, 9),
PACK(2, 14),
PACK(2, 15),
PACK(2, 16),
PACK(3, 11),
PACK(5, 7),
PACK(3, 12),
PACK(3, 13),
PACK(4, 10),
PACK(3, 14),
PACK(4, 11),
PACK(3, 15),
PACK(3, 16),
PACK(7, 7),
PACK(5, 10),
PACK(4, 13),
PACK(6, 9),
PACK(5, 11),
PACK(4, 14),
PACK(4, 15),
PACK(7, 9),
PACK(4, 16),
PACK(5, 13),
PACK(6, 11),
PACK(5, 14),
PACK(6, 12),
PACK(5, 15),
PACK(7, 11),
PACK(6, 13),
PACK(5, 16),
PACK(9, 9),
PACK(6, 14),
PACK(8, 11),
PACK(6, 15),
PACK(7, 13),
PACK(6, 16),
PACK(7, 14),
PACK(9, 11),
PACK(10, 10),
PACK(8, 13),
PACK(7, 15),
PACK(9, 12),
PACK(10, 11),
PACK(7, 16),
PACK(9, 13),
PACK(8, 15),
PACK(11, 11),
PACK(9, 14),
PACK(8, 16),
PACK(10, 13),
PACK(11, 12),
PACK(9, 15),
PACK(10, 14),
PACK(11, 13),
PACK(9, 16),
PACK(10, 15),
PACK(11, 14),
PACK(12, 13),
PACK(10, 16),
PACK(11, 15),
PACK(12, 14),
PACK(13, 13),
PACK(11, 16),
PACK(12, 15),
PACK(13, 14),
PACK(12, 16),
PACK(13, 15),
PACK(14, 14),
PACK(13, 16),
PACK(14, 15),
PACK(14, 16),
PACK(15, 15),
PACK(15, 16),
PACK(16, 16),
};
TEST_STATIC int k210_pll_calc_config(u32 rate, u32 rate_in,
struct k210_pll_config *best)
{
int i;
s64 error, best_error;
u64 ratio, inv_ratio; /* fixed point 32.32 ratio of the rates */
u64 max_r;
u64 r, f, od;
/*
* Can't go over 1.75 GHz or under 21.25 MHz due to limitations on the
* VCO frequency. These are not the same limits as below because od can
* reduce the output frequency by 16.
*/
if (rate > 1750000000 || rate < 21250000)
return -EINVAL;
/* Similar restrictions on the input rate */
if (rate_in > 1750000000 || rate_in < 13300000)
return -EINVAL;
ratio = DIV_ROUND_CLOSEST_ULL((u64)rate << 32, rate_in);
inv_ratio = DIV_ROUND_CLOSEST_ULL((u64)rate_in << 32, rate);
/* Can't increase by more than 64 or reduce by more than 256 */
if (rate > rate_in && ratio > (64ULL << 32))
return -EINVAL;
else if (rate <= rate_in && inv_ratio > (256ULL << 32))
return -EINVAL;
/*
* The divided clock (rate_in / r) must stay between 1.75 GHz and 13.3
* MHz. There is no minimum, since the only way to get a higher input
* clock than 26 MHz is to use a clock generated by a PLL. Because PLLs
* cannot output frequencies greater than 1.75 GHz, the minimum would
* never be greater than one.
*/
max_r = DIV_ROUND_DOWN_ULL(rate_in, 13300000);
/* Variables get immediately incremented, so start at -1th iteration */
i = -1;
f = 0;
r = 0;
od = 0;
best_error = S64_MAX;
error = best_error;
/* do-while here so we always try at least one ratio */
do {
/*
* Whether we swapped r and od while enforcing frequency limits
*/
bool swapped = false;
/*
* Whether the intermediate frequencies are out-of-spec
*/
bool out_of_spec;
u64 last_od = od;
u64 last_r = r;
/*
* Try the next largest value for f (or r and od) and
* recalculate the other parameters based on that
*/
if (rate > rate_in) {
/*
* Skip factors of the same product if we already tried
* out that product
*/
do {
i++;
r = UNPACK_R(factors[i]);
od = UNPACK_OD(factors[i]);
} while (i + 1 < ARRAY_SIZE(factors) &&
r * od == last_r * last_od);
/* Round close */
f = (r * od * ratio + BIT(31)) >> 32;
if (f > 64)
f = 64;
} else {
u64 tmp = ++f * inv_ratio;
bool round_up = !!(tmp & BIT(31));
u32 goal = (tmp >> 32) + round_up;
u32 err, last_err;
/* Get the next r/od pair in factors */
while (r * od < goal && i + 1 < ARRAY_SIZE(factors)) {
i++;
r = UNPACK_R(factors[i]);
od = UNPACK_OD(factors[i]);
}
/*
* This is a case of double rounding. If we rounded up
* above, we need to round down (in cases of ties) here.
* This prevents off-by-one errors resulting from
* choosing X+2 over X when X.Y rounds up to X+1 and
* there is no r * od = X+1. For the converse, when X.Y
* is rounded down to X, we should choose X+1 over X-1.
*/
err = abs(r * od - goal);
last_err = abs(last_r * last_od - goal);
if (last_err < err || (round_up && last_err == err)) {
i--;
r = last_r;
od = last_od;
}
}
/*
* Enforce limits on internal clock frequencies. If we
* aren't in spec, try swapping r and od. If everything is
* in-spec, calculate the relative error.
*/
again:
out_of_spec = false;
if (r > max_r) {
out_of_spec = true;
} else {
/*
* There is no way to only divide once; we need
* to examine the frequency with and without the
* effect of od.
*/
u64 vco = DIV_ROUND_CLOSEST_ULL(rate_in * f, r);
if (vco > 1750000000 || vco < 340000000)
out_of_spec = true;
}
if (out_of_spec) {
u64 new_r, new_od;
if (!swapped) {
u64 tmp = r;
r = od;
od = tmp;
swapped = true;
goto again;
}
/*
* Try looking ahead to see if there are additional
* factors for the same product.
*/
if (i + 1 < ARRAY_SIZE(factors)) {
i++;
new_r = UNPACK_R(factors[i]);
new_od = UNPACK_OD(factors[i]);
if (r * od == new_r * new_od) {
r = new_r;
od = new_od;
swapped = false;
goto again;
}
i--;
}
/*
* Try looking back to see if there is a worse ratio
* that we could try anyway
*/
while (i > 0) {
i--;
new_r = UNPACK_R(factors[i]);
new_od = UNPACK_OD(factors[i]);
/*
* Don't loop over factors for the same product
* to avoid getting stuck because of the above
* clause
*/
if (r * od != new_r * new_od) {
if (new_r * new_od > last_r * last_od) {
r = new_r;
od = new_od;
swapped = false;
goto again;
}
break;
}
}
/* We ran out of things to try */
continue;
}
error = DIV_ROUND_CLOSEST_ULL(f * inv_ratio, r * od);
/* The lower 16 bits are spurious */
error = abs((error - BIT(32))) >> 16;
if (error < best_error) {
best->r = r;
best->f = f;
best->od = od;
best_error = error;
}
} while (f < 64 && i + 1 < ARRAY_SIZE(factors) && error != 0);
log_debug("best error %lld\n", best_error);
if (best_error == S64_MAX)
return -EINVAL;
return 0;
}
static ulong k210_pll_set_rate(struct k210_clk_priv *priv, int id, ulong rate,
ulong rate_in)
{
int err;
const struct k210_pll_params *pll = &k210_plls[id];
struct k210_pll_config config = {};
u32 reg;
ulong calc_rate;
err = k210_pll_calc_config(rate, rate_in, &config);
if (err)
return err;
log_debug("Got r=%u f=%u od=%u\n", config.r, config.f, config.od);
/* Don't bother setting the rate if we're already at that rate */
calc_rate = DIV_ROUND_DOWN_ULL(((u64)rate_in) * config.f,
config.r * config.od);
if (calc_rate == k210_pll_get_rate(priv, id, rate))
return calc_rate;
k210_pll_disable(priv, id);
reg = readl(priv->base + pll->off);
reg &= ~K210_PLL_CLKR
& ~K210_PLL_CLKF
& ~K210_PLL_CLKOD
& ~K210_PLL_BWADJ;
reg |= FIELD_PREP(K210_PLL_CLKR, config.r - 1)
| FIELD_PREP(K210_PLL_CLKF, config.f - 1)
| FIELD_PREP(K210_PLL_CLKOD, config.od - 1)
| FIELD_PREP(K210_PLL_BWADJ, config.f - 1);
writel(reg, priv->base + pll->off);
k210_pll_enable(priv, id);
serial_setbrg();
return k210_pll_get_rate(priv, id, rate);
}
#else
static ulong k210_pll_set_rate(struct k210_clk_priv *priv, int id, ulong rate,
ulong rate_in)
{
return -ENOSYS;
}
#endif /* CONFIG_CLK_K210_SET_RATE */
static ulong k210_pll_get_rate(struct k210_clk_priv *priv, int id,
ulong rate_in)
{
u64 r, f, od;
u32 reg = readl(priv->base + k210_plls[id].off);
if (reg & K210_PLL_BYPASS)
return rate_in;
if (!(reg & K210_PLL_PWRD))
return 0;
r = FIELD_GET(K210_PLL_CLKR, reg) + 1;
f = FIELD_GET(K210_PLL_CLKF, reg) + 1;
od = FIELD_GET(K210_PLL_CLKOD, reg) + 1;
return DIV_ROUND_DOWN_ULL(((u64)rate_in) * f, r * od);
}
/*
* Wait for the PLL to be locked. If the PLL is not locked, try clearing the
* slip before retrying
*/
static void k210_pll_waitfor_lock(struct k210_clk_priv *priv, int id)
{
const struct k210_pll_params *pll = &k210_plls[id];
u32 mask = (BIT(pll->width) - 1) << pll->shift;
while (true) {
u32 reg = readl(priv->base + K210_SYSCTL_PLL_LOCK);
if ((reg & mask) == mask)
break;
reg |= BIT(pll->shift + K210_PLL_CLEAR_SLIP);
writel(reg, priv->base + K210_SYSCTL_PLL_LOCK);
}
}
static bool k210_pll_enabled(u32 reg)
{
return (reg & K210_PLL_PWRD) && (reg & K210_PLL_EN) &&
!(reg & K210_PLL_RESET);
}
/* Adapted from sysctl_pll_enable */
static int k210_pll_enable(struct k210_clk_priv *priv, int id)
{
const struct k210_pll_params *pll = &k210_plls[id];
u32 reg = readl(priv->base + pll->off);
if (k210_pll_enabled(reg))
return 0;
reg |= K210_PLL_PWRD;
writel(reg, priv->base + pll->off);
/* Ensure reset is low before asserting it */
reg &= ~K210_PLL_RESET;
writel(reg, priv->base + pll->off);
reg |= K210_PLL_RESET;
writel(reg, priv->base + pll->off);
nop();
nop();
reg &= ~K210_PLL_RESET;
writel(reg, priv->base + pll->off);
k210_pll_waitfor_lock(priv, id);
reg &= ~K210_PLL_BYPASS;
reg |= K210_PLL_EN;
writel(reg, priv->base + pll->off);
return 0;
}
static int k210_pll_disable(struct k210_clk_priv *priv, int id)
{
const struct k210_pll_params *pll = &k210_plls[id];
u32 reg = readl(priv->base + pll->off);
/*
* Bypassing before powering off is important so child clocks don't stop
* working. This is especially important for pll0, the indirect parent
* of the cpu clock.
*/
reg |= K210_PLL_BYPASS;
writel(reg, priv->base + pll->off);
reg &= ~K210_PLL_PWRD;
reg &= ~K210_PLL_EN;
writel(reg, priv->base + pll->off);
return 0;
}
static u32 k210_clk_readl(struct k210_clk_priv *priv, u8 off, u8 shift,
u8 width)
{
u32 reg = readl(priv->base + off);
return (reg >> shift) & (BIT(width) - 1);
}
static void k210_clk_writel(struct k210_clk_priv *priv, u8 off, u8 shift,
u8 width, u32 val)
{
u32 reg = readl(priv->base + off);
u32 mask = (BIT(width) - 1) << shift;
reg &= ~mask;
reg |= mask & (val << shift);
writel(reg, priv->base + off);
}
static int k210_clk_get_parent(struct k210_clk_priv *priv, int id)
{
u32 sel;
const struct k210_mux_params *mux;
if (!(k210_clks[id].flags & K210_CLKF_MUX))
return k210_clks[id].parent;
mux = &k210_muxes[k210_clks[id].mux];
sel = k210_clk_readl(priv, mux->off, mux->shift, mux->width);
assert(sel < mux->num_parents);
return mux->parents[sel];
}
static ulong do_k210_clk_get_rate(struct k210_clk_priv *priv, int id)
{
int parent;
u32 val;
ulong parent_rate;
const struct k210_div_params *div;
if (id == K210_CLK_IN0)
return clk_get_rate(&priv->in0);
parent = k210_clk_get_parent(priv, id);
parent_rate = do_k210_clk_get_rate(priv, parent);
if (IS_ERR_VALUE(parent_rate))
return parent_rate;
if (k210_clks[id].flags & K210_CLKF_PLL)
return k210_pll_get_rate(priv, k210_clks[id].pll, parent_rate);
if (k210_clks[id].div == K210_CLK_DIV_NONE)
return parent_rate;
div = &k210_divs[k210_clks[id].div];
if (div->type == K210_DIV_FIXED)
return parent_rate / div->div;
val = k210_clk_readl(priv, div->off, div->shift, div->width);
switch (div->type) {
case K210_DIV_ONE:
return parent_rate / (val + 1);
case K210_DIV_EVEN:
return parent_rate / 2 / (val + 1);
case K210_DIV_POWER:
/* This is ACLK, which has no divider on IN0 */
if (parent == K210_CLK_IN0)
return parent_rate;
return parent_rate / (2 << val);
default:
assert(false);
return -EINVAL;
};
}
static ulong k210_clk_get_rate(struct clk *clk)
{
return do_k210_clk_get_rate(dev_get_priv(clk->dev), clk->id);
}
static int do_k210_clk_set_parent(struct k210_clk_priv *priv, int id, int new)
{
int i;
const struct k210_mux_params *mux;
if (!(k210_clks[id].flags & K210_CLKF_MUX))
return -ENOSYS;
mux = &k210_muxes[k210_clks[id].mux];
for (i = 0; i < mux->num_parents; i++) {
if (mux->parents[i] == new) {
k210_clk_writel(priv, mux->off, mux->shift, mux->width,
i);
return 0;
}
}
return -EINVAL;
}
static int k210_clk_set_parent(struct clk *clk, struct clk *parent)
{
return do_k210_clk_set_parent(dev_get_priv(clk->dev), clk->id,
parent->id);
}
static ulong k210_clk_set_rate(struct clk *clk, unsigned long rate)
{
int parent, ret, err;
ulong rate_in, val;
const struct k210_div_params *div;
struct k210_clk_priv *priv = dev_get_priv(clk->dev);
if (clk->id == K210_CLK_IN0)
return clk_set_rate(&priv->in0, rate);
parent = k210_clk_get_parent(priv, clk->id);
rate_in = do_k210_clk_get_rate(priv, parent);
if (IS_ERR_VALUE(rate_in))
return rate_in;
log_debug("id=%ld rate=%lu rate_in=%lu\n", clk->id, rate, rate_in);
if (clk->id == K210_CLK_PLL0) {
/* Bypass ACLK so the CPU keeps going */
ret = do_k210_clk_set_parent(priv, K210_CLK_ACLK, K210_CLK_IN0);
if (ret)
return ret;
} else if (clk->id == K210_CLK_PLL1 && gd->flags & GD_FLG_RELOC) {
/*
* We can't bypass the AI clock like we can ACLK, and after
* relocation we are using the AI ram.
*/
return -EPERM;
}
if (k210_clks[clk->id].flags & K210_CLKF_PLL) {
ret = k210_pll_set_rate(priv, k210_clks[clk->id].pll, rate,
rate_in);
if (!IS_ERR_VALUE(ret) && clk->id == K210_CLK_PLL0) {
/*
* This may have the side effect of reparenting ACLK,
* but I don't really want to keep track of what the old
* parent was.
*/
err = do_k210_clk_set_parent(priv, K210_CLK_ACLK,
K210_CLK_PLL0);
if (err)
return err;
}
return ret;
}
if (k210_clks[clk->id].div == K210_CLK_DIV_NONE)
return -ENOSYS;
div = &k210_divs[k210_clks[clk->id].div];
switch (div->type) {
case K210_DIV_ONE:
val = DIV_ROUND_CLOSEST_ULL((u64)rate_in, rate);
val = val ? val - 1 : 0;
break;
case K210_DIV_EVEN:
val = DIV_ROUND_CLOSEST_ULL((u64)rate_in, 2 * rate);
break;
case K210_DIV_POWER:
/* This is ACLK, which has no divider on IN0 */
if (parent == K210_CLK_IN0)
return -ENOSYS;
val = DIV_ROUND_CLOSEST_ULL((u64)rate_in, rate);
val = __ffs(val);
break;
default:
assert(false);
return -EINVAL;
};
val = val ? val - 1 : 0;
k210_clk_writel(priv, div->off, div->shift, div->width, val);
return do_k210_clk_get_rate(priv, clk->id);
}
static int k210_clk_endisable(struct k210_clk_priv *priv, int id, bool enable)
{
int parent = k210_clk_get_parent(priv, id);
const struct k210_gate_params *gate;
if (id == K210_CLK_IN0) {
if (enable)
return clk_enable(&priv->in0);
else
return clk_disable(&priv->in0);
}
/* Only recursively enable clocks since we don't track refcounts */
if (enable) {
int ret = k210_clk_endisable(priv, parent, true);
if (ret && ret != -ENOSYS)
return ret;
}
if (k210_clks[id].flags & K210_CLKF_PLL) {
if (enable)
return k210_pll_enable(priv, k210_clks[id].pll);
else
return k210_pll_disable(priv, k210_clks[id].pll);
}
if (k210_clks[id].gate == K210_CLK_GATE_NONE)
return -ENOSYS;
gate = &k210_gates[k210_clks[id].gate];
k210_clk_writel(priv, gate->off, gate->bit_idx, 1, enable);
return 0;
}
static int k210_clk_enable(struct clk *clk)
{
return k210_clk_endisable(dev_get_priv(clk->dev), clk->id, true);
}
static int k210_clk_disable(struct clk *clk)
{
return k210_clk_endisable(dev_get_priv(clk->dev), clk->id, false);
}
static int k210_clk_request(struct clk *clk)
{
if (clk->id >= ARRAY_SIZE(k210_clks))
return -EINVAL;
return 0;
}
static const struct clk_ops k210_clk_ops = {
.request = k210_clk_request,
.set_rate = k210_clk_set_rate,
.get_rate = k210_clk_get_rate,
.set_parent = k210_clk_set_parent,
.enable = k210_clk_enable,
.disable = k210_clk_disable,
};
static int k210_clk_probe(struct udevice *dev)
{
int ret;
struct k210_clk_priv *priv = dev_get_priv(dev);
priv->base = dev_read_addr_ptr(dev_get_parent(dev));
if (!priv->base)
return -EINVAL;
ret = clk_get_by_index(dev, 0, &priv->in0);
if (ret)
return ret;
/*
* Force setting defaults, even before relocation. This is so we can
* set the clock rate for PLL1 before we relocate into aisram.
*/
if (!(gd->flags & GD_FLG_RELOC))
clk_set_defaults(dev, CLK_DEFAULTS_POST_FORCE);
return 0;
}
static const struct udevice_id k210_clk_ids[] = {
{ .compatible = "kendryte,k210-clk" },
{ },
};
U_BOOT_DRIVER(k210_clk) = {
.name = "k210_clk",
.id = UCLASS_CLK,
.of_match = k210_clk_ids,
.ops = &k210_clk_ops,
.probe = k210_clk_probe,
.priv_auto = sizeof(struct k210_clk_priv),
};
#if CONFIG_IS_ENABLED(CMD_CLK)
static char show_enabled(struct k210_clk_priv *priv, int id)
{
bool enabled;
if (k210_clks[id].flags & K210_CLKF_PLL) {
const struct k210_pll_params *pll =
&k210_plls[k210_clks[id].pll];
enabled = k210_pll_enabled(readl(priv->base + pll->off));
} else if (k210_clks[id].gate == K210_CLK_GATE_NONE) {
return '-';
} else {
const struct k210_gate_params *gate =
&k210_gates[k210_clks[id].gate];
enabled = k210_clk_readl(priv, gate->off, gate->bit_idx, 1);
}
return enabled ? 'y' : 'n';
}
static void show_clks(struct k210_clk_priv *priv, int id, int depth)
{
int i;
for (i = 0; i < ARRAY_SIZE(k210_clks); i++) {
if (k210_clk_get_parent(priv, i) != id)
continue;
printf(" %-9lu %-7c %*s%s\n", do_k210_clk_get_rate(priv, i),
show_enabled(priv, i), depth * 4, "",
k210_clks[i].name);
show_clks(priv, i, depth + 1);
}
}
int soc_clk_dump(void)
{
int ret;
struct udevice *dev;
struct k210_clk_priv *priv;
ret = uclass_get_device_by_driver(UCLASS_CLK, DM_DRIVER_GET(k210_clk),
&dev);
if (ret)
return ret;
priv = dev_get_priv(dev);
puts(" Rate Enabled Name\n");
puts("------------------------\n");
printf(" %-9lu %-7c %*s%s\n", clk_get_rate(&priv->in0), 'y', 0, "",
priv->in0.dev->name);
show_clks(priv, K210_CLK_IN0, 1);
return 0;
}
#endif
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