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u-boot/cpu/blackfin/initcode.c
Mike Frysinger f790ef6ff1 Blackfin: dynamically update UART speed when initializing 
Previously, booting over the UART required the baud rate to be known ahead
of time.  Using a bit of tricky simple math, we can calculate the new board
rate based on the old divisors.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org>
2009-02-05 21:25:35 -05:00

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/*
* initcode.c - Initialize the processor. This is usually entails things
* like external memory, voltage regulators, etc... Note that this file
* cannot make any function calls as it may be executed all by itself by
* the Blackfin's bootrom in LDR format.
*
* Copyright (c) 2004-2008 Analog Devices Inc.
*
* Licensed under the GPL-2 or later.
*/
#include <config.h>
#include <asm/blackfin.h>
#include <asm/mach-common/bits/bootrom.h>
#include <asm/mach-common/bits/ebiu.h>
#include <asm/mach-common/bits/pll.h>
#include <asm/mach-common/bits/uart.h>
#define BFIN_IN_INITCODE
#include "serial.h"
__attribute__((always_inline))
static inline void serial_init(void)
{
#ifdef __ADSPBF54x__
# ifdef BFIN_BOOT_UART_USE_RTS
# define BFIN_UART_USE_RTS 1
# else
# define BFIN_UART_USE_RTS 0
# endif
if (BFIN_UART_USE_RTS && CONFIG_BFIN_BOOT_MODE == BFIN_BOOT_UART) {
size_t i;
/* force RTS rather than relying on auto RTS */
bfin_write_UART1_MCR(bfin_read_UART1_MCR() | FCPOL);
/* Wait for the line to clear up. We cannot rely on UART
* registers as none of them reflect the status of the RSR.
* Instead, we'll sleep for ~10 bit times at 9600 baud.
* We can precalc things here by assuming boot values for
* PLL rather than loading registers and calculating.
* baud = SCLK / (16 ^ (1 - EDBO) * Divisor)
* EDB0 = 0
* Divisor = (SCLK / baud) / 16
* SCLK = baud * 16 * Divisor
* SCLK = (0x14 * CONFIG_CLKIN_HZ) / 5
* CCLK = (16 * Divisor * 5) * (9600 / 10)
* In reality, this will probably be just about 1 second delay,
* so assuming 9600 baud is OK (both as a very low and too high
* speed as this will buffer things enough).
*/
#define _NUMBITS (10) /* how many bits to delay */
#define _LOWBAUD (9600) /* low baud rate */
#define _SCLK ((0x14 * CONFIG_CLKIN_HZ) / 5) /* SCLK based on PLL */
#define _DIVISOR ((_SCLK / _LOWBAUD) / 16) /* UART DLL/DLH */
#define _NUMINS (3) /* how many instructions in loop */
#define _CCLK (((16 * _DIVISOR * 5) * (_LOWBAUD / _NUMBITS)) / _NUMINS)
i = _CCLK;
while (i--)
asm volatile("" : : : "memory");
}
#endif
if (BFIN_DEBUG_EARLY_SERIAL) {
int ucen = *pUART_GCTL & UCEN;
serial_early_init();
/* If the UART is off, that means we need to program
* the baud rate ourselves initially.
*/
if (ucen != UCEN)
serial_early_set_baud(CONFIG_BAUDRATE);
}
}
__attribute__((always_inline))
static inline void serial_deinit(void)
{
#ifdef __ADSPBF54x__
if (BFIN_UART_USE_RTS && CONFIG_BFIN_BOOT_MODE == BFIN_BOOT_UART) {
/* clear forced RTS rather than relying on auto RTS */
bfin_write_UART1_MCR(bfin_read_UART1_MCR() & ~FCPOL);
}
#endif
}
__attribute__((always_inline))
static inline void serial_putc(char c)
{
if (!BFIN_DEBUG_EARLY_SERIAL)
return;
if (c == '\n')
*pUART_THR = '\r';
*pUART_THR = c;
while (!(*pUART_LSR & TEMT))
continue;
}
/* Max SCLK can be 133MHz ... dividing that by (2*4) gives
* us a freq of 16MHz for SPI which should generally be
* slow enough for the slow reads the bootrom uses.
*/
#if !defined(CONFIG_SPI_FLASH_SLOW_READ) && \
((defined(__ADSPBF52x__) && __SILICON_REVISION__ >= 2) || \
(defined(__ADSPBF54x__) && __SILICON_REVISION__ >= 1))
# define BOOTROM_SUPPORTS_SPI_FAST_READ 1
#else
# define BOOTROM_SUPPORTS_SPI_FAST_READ 0
#endif
#ifndef CONFIG_SPI_BAUD_INITBLOCK
# define CONFIG_SPI_BAUD_INITBLOCK (BOOTROM_SUPPORTS_SPI_FAST_READ ? 2 : 4)
#endif
#ifdef SPI0_BAUD
# define bfin_write_SPI_BAUD bfin_write_SPI0_BAUD
#endif
/* PLL_DIV defines */
#ifndef CONFIG_PLL_DIV_VAL
# if (CONFIG_CCLK_DIV == 1)
# define CONFIG_CCLK_ACT_DIV CCLK_DIV1
# elif (CONFIG_CCLK_DIV == 2)
# define CONFIG_CCLK_ACT_DIV CCLK_DIV2
# elif (CONFIG_CCLK_DIV == 4)
# define CONFIG_CCLK_ACT_DIV CCLK_DIV4
# elif (CONFIG_CCLK_DIV == 8)
# define CONFIG_CCLK_ACT_DIV CCLK_DIV8
# else
# define CONFIG_CCLK_ACT_DIV CONFIG_CCLK_DIV_not_defined_properly
# endif
# define CONFIG_PLL_DIV_VAL (CONFIG_CCLK_ACT_DIV | CONFIG_SCLK_DIV)
#endif
#ifndef CONFIG_PLL_LOCKCNT_VAL
# define CONFIG_PLL_LOCKCNT_VAL 0x0300
#endif
#ifndef CONFIG_PLL_CTL_VAL
# define CONFIG_PLL_CTL_VAL (SPORT_HYST | (CONFIG_VCO_MULT << 9) | CONFIG_CLKIN_HALF)
#endif
#ifndef CONFIG_EBIU_RSTCTL_VAL
# define CONFIG_EBIU_RSTCTL_VAL 0 /* only MDDRENABLE is useful */
#endif
#if ((CONFIG_EBIU_RSTCTL_VAL & 0xFFFFFFC4) != 0)
# error invalid EBIU_RSTCTL value: must not set reserved bits
#endif
#ifndef CONFIG_EBIU_MBSCTL_VAL
# define CONFIG_EBIU_MBSCTL_VAL 0
#endif
#if defined(CONFIG_EBIU_DDRQUE_VAL) && ((CONFIG_EBIU_DDRQUE_VAL & 0xFFFF8000) != 0)
# error invalid EBIU_DDRQUE value: must not set reserved bits
#endif
/* Make sure our voltage value is sane so we don't blow up! */
#ifndef CONFIG_VR_CTL_VAL
# define BFIN_CCLK ((CONFIG_CLKIN_HZ * CONFIG_VCO_MULT) / CONFIG_CCLK_DIV)
# if defined(__ADSPBF533__) || defined(__ADSPBF532__) || defined(__ADSPBF531__)
# define CCLK_VLEV_120 400000000
# define CCLK_VLEV_125 533000000
# elif defined(__ADSPBF537__) || defined(__ADSPBF536__) || defined(__ADSPBF534__)
# define CCLK_VLEV_120 401000000
# define CCLK_VLEV_125 401000000
# elif defined(__ADSPBF561__)
# define CCLK_VLEV_120 300000000
# define CCLK_VLEV_125 501000000
# endif
# if BFIN_CCLK < CCLK_VLEV_120
# define CONFIG_VR_CTL_VLEV VLEV_120
# elif BFIN_CCLK < CCLK_VLEV_125
# define CONFIG_VR_CTL_VLEV VLEV_125
# else
# define CONFIG_VR_CTL_VLEV VLEV_130
# endif
# if defined(__ADSPBF52x__) /* TBD; use default */
# undef CONFIG_VR_CTL_VLEV
# define CONFIG_VR_CTL_VLEV VLEV_110
# elif defined(__ADSPBF54x__) /* TBD; use default */
# undef CONFIG_VR_CTL_VLEV
# define CONFIG_VR_CTL_VLEV VLEV_120
# elif defined(__ADSPBF538__) || defined(__ADSPBF539__) /* TBD; use default */
# undef CONFIG_VR_CTL_VLEV
# define CONFIG_VR_CTL_VLEV VLEV_125
# endif
# ifdef CONFIG_BFIN_MAC
# define CONFIG_VR_CTL_CLKBUF CLKBUFOE
# else
# define CONFIG_VR_CTL_CLKBUF 0
# endif
# if defined(__ADSPBF52x__)
# define CONFIG_VR_CTL_FREQ FREQ_1000
# else
# define CONFIG_VR_CTL_FREQ (GAIN_20 | FREQ_1000)
# endif
# define CONFIG_VR_CTL_VAL (CONFIG_VR_CTL_CLKBUF | CONFIG_VR_CTL_VLEV | CONFIG_VR_CTL_FREQ)
#endif
BOOTROM_CALLED_FUNC_ATTR
void initcode(ADI_BOOT_DATA *bootstruct)
{
/* Save the clock pieces that are used in baud rate calculation */
unsigned int sdivB, divB, vcoB;
serial_init();
if (BFIN_DEBUG_EARLY_SERIAL || CONFIG_BFIN_BOOT_MODE == BFIN_BOOT_UART) {
sdivB = bfin_read_PLL_DIV() & 0xf;
vcoB = (bfin_read_PLL_CTL() >> 9) & 0x3f;
divB = serial_early_get_div();
}
#ifdef CONFIG_HW_WATCHDOG
# ifndef CONFIG_HW_WATCHDOG_TIMEOUT_INITCODE
# define CONFIG_HW_WATCHDOG_TIMEOUT_INITCODE 20000
# endif
/* Program the watchdog with an initial timeout of ~20 seconds.
* Hopefully that should be long enough to load the u-boot LDR
* (from wherever) and then the common u-boot code can take over.
* In bypass mode, the start.S would have already set a much lower
* timeout, so don't clobber that.
*/
if (CONFIG_BFIN_BOOT_MODE != BFIN_BOOT_BYPASS) {
bfin_write_WDOG_CNT(MSEC_TO_SCLK(CONFIG_HW_WATCHDOG_TIMEOUT_INITCODE));
bfin_write_WDOG_CTL(0);
}
#endif
serial_putc('S');
/* Blackfin bootroms use the SPI slow read opcode instead of the SPI
* fast read, so we need to slow down the SPI clock a lot more during
* boot. Once we switch over to u-boot's SPI flash driver, we'll
* increase the speed appropriately.
*/
if (CONFIG_BFIN_BOOT_MODE == BFIN_BOOT_SPI_MASTER) {
if (BOOTROM_SUPPORTS_SPI_FAST_READ && CONFIG_SPI_BAUD_INITBLOCK < 4)
bootstruct->dFlags |= BFLAG_FASTREAD;
bfin_write_SPI_BAUD(CONFIG_SPI_BAUD_INITBLOCK);
}
serial_putc('B');
/* Disable all peripheral wakeups except for the PLL event. */
#ifdef SIC_IWR0
bfin_write_SIC_IWR0(1);
bfin_write_SIC_IWR1(0);
# ifdef SIC_IWR2
bfin_write_SIC_IWR2(0);
# endif
#elif defined(SICA_IWR0)
bfin_write_SICA_IWR0(1);
bfin_write_SICA_IWR1(0);
#else
bfin_write_SIC_IWR(1);
#endif
/* With newer bootroms, we use the helper function to set up
* the memory controller. Older bootroms lacks such helpers
* so we do it ourselves.
*/
if (BOOTROM_CAPS_SYSCONTROL) {
serial_putc('S');
ADI_SYSCTRL_VALUES memory_settings;
memory_settings.uwVrCtl = CONFIG_VR_CTL_VAL;
memory_settings.uwPllCtl = CONFIG_PLL_CTL_VAL;
memory_settings.uwPllDiv = CONFIG_PLL_DIV_VAL;
memory_settings.uwPllLockCnt = CONFIG_PLL_LOCKCNT_VAL;
syscontrol(SYSCTRL_WRITE | SYSCTRL_VRCTL | SYSCTRL_PLLCTL | SYSCTRL_PLLDIV | SYSCTRL_LOCKCNT |
(CONFIG_VR_CTL_VAL & FREQ_MASK ? SYSCTRL_INTVOLTAGE : SYSCTRL_EXTVOLTAGE), &memory_settings, NULL);
} else {
serial_putc('L');
bfin_write_PLL_LOCKCNT(CONFIG_PLL_LOCKCNT_VAL);
serial_putc('A');
/* Only reprogram when needed to avoid triggering unnecessary
* PLL relock sequences.
*/
if (bfin_read_VR_CTL() != CONFIG_VR_CTL_VAL) {
serial_putc('!');
bfin_write_VR_CTL(CONFIG_VR_CTL_VAL);
asm("idle;");
}
serial_putc('C');
bfin_write_PLL_DIV(CONFIG_PLL_DIV_VAL);
serial_putc('K');
/* Only reprogram when needed to avoid triggering unnecessary
* PLL relock sequences.
*/
if (bfin_read_PLL_CTL() != CONFIG_PLL_CTL_VAL) {
serial_putc('!');
bfin_write_PLL_CTL(CONFIG_PLL_CTL_VAL);
asm("idle;");
}
}
/* Since we've changed the SCLK above, we may need to update
* the UART divisors (UART baud rates are based on SCLK).
* Do the division by hand as there are no native instructions
* for dividing which means we'd generate a libgcc reference.
*/
if (CONFIG_BFIN_BOOT_MODE == BFIN_BOOT_UART) {
unsigned int sdivR, vcoR;
sdivR = bfin_read_PLL_DIV() & 0xf;
vcoR = (bfin_read_PLL_CTL() >> 9) & 0x3f;
int dividend = sdivB * divB * vcoR;
int divisor = vcoB * sdivR;
unsigned int quotient;
for (quotient = 0; dividend > 0; ++quotient)
dividend -= divisor;
serial_early_put_div(quotient - ANOMALY_05000230);
}
serial_putc('F');
/* Program the async banks controller. */
bfin_write_EBIU_AMBCTL0(CONFIG_EBIU_AMBCTL0_VAL);
bfin_write_EBIU_AMBCTL1(CONFIG_EBIU_AMBCTL1_VAL);
bfin_write_EBIU_AMGCTL(CONFIG_EBIU_AMGCTL_VAL);
#ifdef EBIU_MODE
/* Not all parts have these additional MMRs. */
bfin_write_EBIU_MBSCTL(CONFIG_EBIU_MBSCTL_VAL);
bfin_write_EBIU_MODE(CONFIG_EBIU_MODE_VAL);
bfin_write_EBIU_FCTL(CONFIG_EBIU_FCTL_VAL);
#endif
serial_putc('I');
/* Program the external memory controller. */
#ifdef EBIU_RSTCTL
bfin_write_EBIU_RSTCTL(bfin_read_EBIU_RSTCTL() | 0x1 /*DDRSRESET*/ | CONFIG_EBIU_RSTCTL_VAL);
bfin_write_EBIU_DDRCTL0(CONFIG_EBIU_DDRCTL0_VAL);
bfin_write_EBIU_DDRCTL1(CONFIG_EBIU_DDRCTL1_VAL);
bfin_write_EBIU_DDRCTL2(CONFIG_EBIU_DDRCTL2_VAL);
# ifdef CONFIG_EBIU_DDRCTL3_VAL
/* default is disable, so don't need to force this */
bfin_write_EBIU_DDRCTL3(CONFIG_EBIU_DDRCTL3_VAL);
# endif
#else
bfin_write_EBIU_SDRRC(CONFIG_EBIU_SDRRC_VAL);
bfin_write_EBIU_SDBCTL(CONFIG_EBIU_SDBCTL_VAL);
bfin_write_EBIU_SDGCTL(CONFIG_EBIU_SDGCTL_VAL);
#endif
serial_putc('N');
/* Restore all peripheral wakeups. */
#ifdef SIC_IWR0
bfin_write_SIC_IWR0(-1);
bfin_write_SIC_IWR1(-1);
# ifdef SIC_IWR2
bfin_write_SIC_IWR2(-1);
# endif
#elif defined(SICA_IWR0)
bfin_write_SICA_IWR0(-1);
bfin_write_SICA_IWR1(-1);
#else
bfin_write_SIC_IWR(-1);
#endif
serial_putc('>');
serial_putc('\n');
serial_deinit();
}
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