u-boot/arch/arm/cpu/arm926ejs/mxs/clock.c

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/*
* Freescale i.MX23/i.MX28 clock setup code
*
* Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
* on behalf of DENX Software Engineering GmbH
*
* Based on code from LTIB:
* Copyright (C) 2010 Freescale Semiconductor, Inc.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <asm/errno.h>
#include <asm/io.h>
#include <asm/arch/clock.h>
#include <asm/arch/imx-regs.h>
/*
* The PLL frequency is 480MHz and XTAL frequency is 24MHz
* iMX23: datasheet section 4.2
* iMX28: datasheet section 10.2
*/
#define PLL_FREQ_KHZ 480000
#define PLL_FREQ_COEF 18
#define XTAL_FREQ_KHZ 24000
#define PLL_FREQ_MHZ (PLL_FREQ_KHZ / 1000)
#define XTAL_FREQ_MHZ (XTAL_FREQ_KHZ / 1000)
#if defined(CONFIG_MX23)
#define MXC_SSPCLK_MAX MXC_SSPCLK0
#elif defined(CONFIG_MX28)
#define MXC_SSPCLK_MAX MXC_SSPCLK3
#endif
static uint32_t mxs_get_pclk(void)
{
struct mxs_clkctrl_regs *clkctrl_regs =
(struct mxs_clkctrl_regs *)MXS_CLKCTRL_BASE;
uint32_t clkctrl, clkseq, div;
uint8_t clkfrac, frac;
clkctrl = readl(&clkctrl_regs->hw_clkctrl_cpu);
/* No support of fractional divider calculation */
if (clkctrl &
(CLKCTRL_CPU_DIV_XTAL_FRAC_EN | CLKCTRL_CPU_DIV_CPU_FRAC_EN)) {
return 0;
}
clkseq = readl(&clkctrl_regs->hw_clkctrl_clkseq);
/* XTAL Path */
if (clkseq & CLKCTRL_CLKSEQ_BYPASS_CPU) {
div = (clkctrl & CLKCTRL_CPU_DIV_XTAL_MASK) >>
CLKCTRL_CPU_DIV_XTAL_OFFSET;
return XTAL_FREQ_MHZ / div;
}
/* REF Path */
clkfrac = readb(&clkctrl_regs->hw_clkctrl_frac0[CLKCTRL_FRAC0_CPU]);
frac = clkfrac & CLKCTRL_FRAC_FRAC_MASK;
div = clkctrl & CLKCTRL_CPU_DIV_CPU_MASK;
return (PLL_FREQ_MHZ * PLL_FREQ_COEF / frac) / div;
}
static uint32_t mxs_get_hclk(void)
{
struct mxs_clkctrl_regs *clkctrl_regs =
(struct mxs_clkctrl_regs *)MXS_CLKCTRL_BASE;
uint32_t div;
uint32_t clkctrl;
clkctrl = readl(&clkctrl_regs->hw_clkctrl_hbus);
/* No support of fractional divider calculation */
if (clkctrl & CLKCTRL_HBUS_DIV_FRAC_EN)
return 0;
div = clkctrl & CLKCTRL_HBUS_DIV_MASK;
return mxs_get_pclk() / div;
}
static uint32_t mxs_get_emiclk(void)
{
struct mxs_clkctrl_regs *clkctrl_regs =
(struct mxs_clkctrl_regs *)MXS_CLKCTRL_BASE;
uint32_t clkctrl, clkseq, div;
uint8_t clkfrac, frac;
clkseq = readl(&clkctrl_regs->hw_clkctrl_clkseq);
clkctrl = readl(&clkctrl_regs->hw_clkctrl_emi);
/* XTAL Path */
if (clkseq & CLKCTRL_CLKSEQ_BYPASS_EMI) {
div = (clkctrl & CLKCTRL_EMI_DIV_XTAL_MASK) >>
CLKCTRL_EMI_DIV_XTAL_OFFSET;
return XTAL_FREQ_MHZ / div;
}
/* REF Path */
clkfrac = readb(&clkctrl_regs->hw_clkctrl_frac0[CLKCTRL_FRAC0_EMI]);
frac = clkfrac & CLKCTRL_FRAC_FRAC_MASK;
div = clkctrl & CLKCTRL_EMI_DIV_EMI_MASK;
return (PLL_FREQ_MHZ * PLL_FREQ_COEF / frac) / div;
}
static uint32_t mxs_get_gpmiclk(void)
{
struct mxs_clkctrl_regs *clkctrl_regs =
(struct mxs_clkctrl_regs *)MXS_CLKCTRL_BASE;
#if defined(CONFIG_MX23)
uint8_t *reg =
&clkctrl_regs->hw_clkctrl_frac0[CLKCTRL_FRAC0_CPU];
#elif defined(CONFIG_MX28)
uint8_t *reg =
&clkctrl_regs->hw_clkctrl_frac1[CLKCTRL_FRAC1_GPMI];
#endif
uint32_t clkctrl, clkseq, div;
uint8_t clkfrac, frac;
clkseq = readl(&clkctrl_regs->hw_clkctrl_clkseq);
clkctrl = readl(&clkctrl_regs->hw_clkctrl_gpmi);
/* XTAL Path */
if (clkseq & CLKCTRL_CLKSEQ_BYPASS_GPMI) {
div = clkctrl & CLKCTRL_GPMI_DIV_MASK;
return XTAL_FREQ_MHZ / div;
}
/* REF Path */
clkfrac = readb(reg);
frac = clkfrac & CLKCTRL_FRAC_FRAC_MASK;
div = clkctrl & CLKCTRL_GPMI_DIV_MASK;
return (PLL_FREQ_MHZ * PLL_FREQ_COEF / frac) / div;
}
/*
* Set IO clock frequency, in kHz
*/
void mxs_set_ioclk(enum mxs_ioclock io, uint32_t freq)
{
struct mxs_clkctrl_regs *clkctrl_regs =
(struct mxs_clkctrl_regs *)MXS_CLKCTRL_BASE;
uint32_t div;
int io_reg;
if (freq == 0)
return;
if ((io < MXC_IOCLK0) || (io > MXC_IOCLK1))
return;
div = (PLL_FREQ_KHZ * PLL_FREQ_COEF) / freq;
if (div < 18)
div = 18;
if (div > 35)
div = 35;
io_reg = CLKCTRL_FRAC0_IO0 - io; /* Register order is reversed */
writeb(CLKCTRL_FRAC_CLKGATE,
&clkctrl_regs->hw_clkctrl_frac0_set[io_reg]);
writeb(CLKCTRL_FRAC_CLKGATE | (div & CLKCTRL_FRAC_FRAC_MASK),
&clkctrl_regs->hw_clkctrl_frac0[io_reg]);
writeb(CLKCTRL_FRAC_CLKGATE,
&clkctrl_regs->hw_clkctrl_frac0_clr[io_reg]);
}
/*
* Get IO clock, returns IO clock in kHz
*/
static uint32_t mxs_get_ioclk(enum mxs_ioclock io)
{
struct mxs_clkctrl_regs *clkctrl_regs =
(struct mxs_clkctrl_regs *)MXS_CLKCTRL_BASE;
uint8_t ret;
int io_reg;
if ((io < MXC_IOCLK0) || (io > MXC_IOCLK1))
return 0;
io_reg = CLKCTRL_FRAC0_IO0 - io; /* Register order is reversed */
ret = readb(&clkctrl_regs->hw_clkctrl_frac0[io_reg]) &
CLKCTRL_FRAC_FRAC_MASK;
return (PLL_FREQ_KHZ * PLL_FREQ_COEF) / ret;
}
/*
* Configure SSP clock frequency, in kHz
*/
void mxs_set_sspclk(enum mxs_sspclock ssp, uint32_t freq, int xtal)
{
struct mxs_clkctrl_regs *clkctrl_regs =
(struct mxs_clkctrl_regs *)MXS_CLKCTRL_BASE;
uint32_t clk, clkreg;
if (ssp > MXC_SSPCLK_MAX)
return;
clkreg = (uint32_t)(&clkctrl_regs->hw_clkctrl_ssp0) +
(ssp * sizeof(struct mxs_register_32));
clrbits_le32(clkreg, CLKCTRL_SSP_CLKGATE);
while (readl(clkreg) & CLKCTRL_SSP_CLKGATE)
;
if (xtal)
clk = XTAL_FREQ_KHZ;
else
clk = mxs_get_ioclk(ssp >> 1);
if (freq > clk)
return;
/* Calculate the divider and cap it if necessary */
clk /= freq;
if (clk > CLKCTRL_SSP_DIV_MASK)
clk = CLKCTRL_SSP_DIV_MASK;
clrsetbits_le32(clkreg, CLKCTRL_SSP_DIV_MASK, clk);
while (readl(clkreg) & CLKCTRL_SSP_BUSY)
;
if (xtal)
writel(CLKCTRL_CLKSEQ_BYPASS_SSP0 << ssp,
&clkctrl_regs->hw_clkctrl_clkseq_set);
else
writel(CLKCTRL_CLKSEQ_BYPASS_SSP0 << ssp,
&clkctrl_regs->hw_clkctrl_clkseq_clr);
}
/*
* Return SSP frequency, in kHz
*/
static uint32_t mxs_get_sspclk(enum mxs_sspclock ssp)
{
struct mxs_clkctrl_regs *clkctrl_regs =
(struct mxs_clkctrl_regs *)MXS_CLKCTRL_BASE;
uint32_t clkreg;
uint32_t clk, tmp;
if (ssp > MXC_SSPCLK_MAX)
return 0;
tmp = readl(&clkctrl_regs->hw_clkctrl_clkseq);
if (tmp & (CLKCTRL_CLKSEQ_BYPASS_SSP0 << ssp))
return XTAL_FREQ_KHZ;
clkreg = (uint32_t)(&clkctrl_regs->hw_clkctrl_ssp0) +
(ssp * sizeof(struct mxs_register_32));
tmp = readl(clkreg) & CLKCTRL_SSP_DIV_MASK;
if (tmp == 0)
return 0;
clk = mxs_get_ioclk(ssp >> 1);
return clk / tmp;
}
/*
* Set SSP/MMC bus frequency, in kHz)
*/
void mxs_set_ssp_busclock(unsigned int bus, uint32_t freq)
{
struct mxs_ssp_regs *ssp_regs;
const enum mxs_sspclock clk = mxs_ssp_clock_by_bus(bus);
const uint32_t sspclk = mxs_get_sspclk(clk);
uint32_t reg;
uint32_t divide, rate, tgtclk;
ssp_regs = mxs_ssp_regs_by_bus(bus);
/*
* SSP bit rate = SSPCLK / (CLOCK_DIVIDE * (1 + CLOCK_RATE)),
* CLOCK_DIVIDE has to be an even value from 2 to 254, and
* CLOCK_RATE could be any integer from 0 to 255.
*/
for (divide = 2; divide < 254; divide += 2) {
rate = sspclk / freq / divide;
if (rate <= 256)
break;
}
tgtclk = sspclk / divide / rate;
while (tgtclk > freq) {
rate++;
tgtclk = sspclk / divide / rate;
}
if (rate > 256)
rate = 256;
/* Always set timeout the maximum */
reg = SSP_TIMING_TIMEOUT_MASK |
(divide << SSP_TIMING_CLOCK_DIVIDE_OFFSET) |
((rate - 1) << SSP_TIMING_CLOCK_RATE_OFFSET);
writel(reg, &ssp_regs->hw_ssp_timing);
debug("SPI%d: Set freq rate to %d KHz (requested %d KHz)\n",
bus, tgtclk, freq);
}
void mxs_set_lcdclk(uint32_t freq)
{
struct mxs_clkctrl_regs *clkctrl_regs =
(struct mxs_clkctrl_regs *)MXS_CLKCTRL_BASE;
uint32_t fp, x, k_rest, k_best, x_best, tk;
int32_t k_best_l = 999, k_best_t = 0, x_best_l = 0xff, x_best_t = 0xff;
if (freq == 0)
return;
#if defined(CONFIG_MX23)
writel(CLKCTRL_CLKSEQ_BYPASS_PIX, &clkctrl_regs->hw_clkctrl_clkseq_clr);
#elif defined(CONFIG_MX28)
writel(CLKCTRL_CLKSEQ_BYPASS_DIS_LCDIF, &clkctrl_regs->hw_clkctrl_clkseq_clr);
#endif
/*
* / 18 \ 1 1
* freq kHz = | 480000000 Hz * -- | * --- * ------
* \ x / k 1000
*
* 480000000 Hz 18
* ------------ * --
* freq kHz x
* k = -------------------
* 1000
*/
fp = ((PLL_FREQ_KHZ * 1000) / freq) * 18;
for (x = 18; x <= 35; x++) {
tk = fp / x;
if ((tk / 1000 == 0) || (tk / 1000 > 255))
continue;
k_rest = tk % 1000;
if (k_rest < (k_best_l % 1000)) {
k_best_l = tk;
x_best_l = x;
}
if (k_rest > (k_best_t % 1000)) {
k_best_t = tk;
x_best_t = x;
}
}
if (1000 - (k_best_t % 1000) > (k_best_l % 1000)) {
k_best = k_best_l;
x_best = x_best_l;
} else {
k_best = k_best_t;
x_best = x_best_t;
}
k_best /= 1000;
#if defined(CONFIG_MX23)
writeb(CLKCTRL_FRAC_CLKGATE,
&clkctrl_regs->hw_clkctrl_frac0_set[CLKCTRL_FRAC0_PIX]);
writeb(CLKCTRL_FRAC_CLKGATE | (x_best & CLKCTRL_FRAC_FRAC_MASK),
&clkctrl_regs->hw_clkctrl_frac0[CLKCTRL_FRAC0_PIX]);
writeb(CLKCTRL_FRAC_CLKGATE,
&clkctrl_regs->hw_clkctrl_frac0_clr[CLKCTRL_FRAC0_PIX]);
writel(CLKCTRL_PIX_CLKGATE,
&clkctrl_regs->hw_clkctrl_pix_set);
clrsetbits_le32(&clkctrl_regs->hw_clkctrl_pix,
CLKCTRL_PIX_DIV_MASK | CLKCTRL_PIX_CLKGATE,
k_best << CLKCTRL_PIX_DIV_OFFSET);
while (readl(&clkctrl_regs->hw_clkctrl_pix) & CLKCTRL_PIX_BUSY)
;
#elif defined(CONFIG_MX28)
writeb(CLKCTRL_FRAC_CLKGATE,
&clkctrl_regs->hw_clkctrl_frac1_set[CLKCTRL_FRAC1_PIX]);
writeb(CLKCTRL_FRAC_CLKGATE | (x_best & CLKCTRL_FRAC_FRAC_MASK),
&clkctrl_regs->hw_clkctrl_frac1[CLKCTRL_FRAC1_PIX]);
writeb(CLKCTRL_FRAC_CLKGATE,
&clkctrl_regs->hw_clkctrl_frac1_clr[CLKCTRL_FRAC1_PIX]);
writel(CLKCTRL_DIS_LCDIF_CLKGATE,
&clkctrl_regs->hw_clkctrl_lcdif_set);
clrsetbits_le32(&clkctrl_regs->hw_clkctrl_lcdif,
CLKCTRL_DIS_LCDIF_DIV_MASK | CLKCTRL_DIS_LCDIF_CLKGATE,
k_best << CLKCTRL_DIS_LCDIF_DIV_OFFSET);
while (readl(&clkctrl_regs->hw_clkctrl_lcdif) & CLKCTRL_DIS_LCDIF_BUSY)
;
#endif
}
uint32_t mxc_get_clock(enum mxc_clock clk)
{
switch (clk) {
case MXC_ARM_CLK:
return mxs_get_pclk() * 1000000;
case MXC_GPMI_CLK:
return mxs_get_gpmiclk() * 1000000;
case MXC_AHB_CLK:
case MXC_IPG_CLK:
return mxs_get_hclk() * 1000000;
case MXC_EMI_CLK:
return mxs_get_emiclk();
case MXC_IO0_CLK:
return mxs_get_ioclk(MXC_IOCLK0);
case MXC_IO1_CLK:
return mxs_get_ioclk(MXC_IOCLK1);
case MXC_XTAL_CLK:
return XTAL_FREQ_KHZ * 1000;
case MXC_SSP0_CLK:
return mxs_get_sspclk(MXC_SSPCLK0);
#ifdef CONFIG_MX28
case MXC_SSP1_CLK:
return mxs_get_sspclk(MXC_SSPCLK1);
case MXC_SSP2_CLK:
return mxs_get_sspclk(MXC_SSPCLK2);
case MXC_SSP3_CLK:
return mxs_get_sspclk(MXC_SSPCLK3);
#endif
}
return 0;
}