diff options
Diffstat (limited to 'arch/powerpc/cpu/ppc4xx/4xx_uart.c')
| -rw-r--r-- | arch/powerpc/cpu/ppc4xx/4xx_uart.c | 307 |
1 files changed, 307 insertions, 0 deletions
diff --git a/arch/powerpc/cpu/ppc4xx/4xx_uart.c b/arch/powerpc/cpu/ppc4xx/4xx_uart.c new file mode 100644 index 0000000..2ab185f --- /dev/null +++ b/arch/powerpc/cpu/ppc4xx/4xx_uart.c @@ -0,0 +1,307 @@ +/* + * (C) Copyright 2000-2006 + * Wolfgang Denk, DENX Software Engineering, wd@denx.de. + * + * (C) Copyright 2010 + * Stefan Roese, DENX Software Engineering, sr@denx.de. + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +/* + * This source code is dual-licensed. You may use it under the terms of the + * GNU General Public License version 2, or under the license below. + * + * This source code has been made available to you by IBM on an AS-IS + * basis. Anyone receiving this source is licensed under IBM + * copyrights to use it in any way he or she deems fit, including + * copying it, modifying it, compiling it, and redistributing it either + * with or without modifications. No license under IBM patents or + * patent applications is to be implied by the copyright license. + * + * Any user of this software should understand that IBM cannot provide + * technical support for this software and will not be responsible for + * any consequences resulting from the use of this software. + * + * Any person who transfers this source code or any derivative work + * must include the IBM copyright notice, this paragraph, and the + * preceding two paragraphs in the transferred software. + * + * COPYRIGHT I B M CORPORATION 1995 + * LICENSED MATERIAL - PROGRAM PROPERTY OF I B M + */ + +#include <common.h> +#include <commproc.h> +#include <asm/processor.h> +#include <asm/io.h> +#include <watchdog.h> +#include <asm/ppc4xx.h> + +DECLARE_GLOBAL_DATA_PTR; + +#if defined(CONFIG_405GP) || defined(CONFIG_405CR) || \ + defined(CONFIG_405EP) || defined(CONFIG_405EZ) || \ + defined(CONFIG_405EX) || defined(CONFIG_440) + +#if defined(CONFIG_440) + +#if defined(CONFIG_440GP) +#define CR0_MASK 0x3fff0000 +#define CR0_EXTCLK_ENA 0x00600000 +#define CR0_UDIV_POS 16 +#define UDIV_SUBTRACT 1 +#define UART0_SDR CPC0_CR0 +#define MFREG(a, d) d = mfdcr(a) +#define MTREG(a, d) mtdcr(a, d) +#else /* #if defined(CONFIG_440GP) */ +/* all other 440 PPC's access clock divider via sdr register */ +#define CR0_MASK 0xdfffffff +#define CR0_EXTCLK_ENA 0x00800000 +#define CR0_UDIV_POS 0 +#define UDIV_SUBTRACT 0 +#define UART0_SDR SDR0_UART0 +#define UART1_SDR SDR0_UART1 +#if defined(CONFIG_440EP) || defined(CONFIG_440EPX) || \ + defined(CONFIG_440GR) || defined(CONFIG_440GRX) || \ + defined(CONFIG_440SP) || defined(CONFIG_440SPE) || \ + defined(CONFIG_460EX) || defined(CONFIG_460GT) +#define UART2_SDR SDR0_UART2 +#endif +#if defined(CONFIG_440EP) || defined(CONFIG_440EPX) || \ + defined(CONFIG_440GR) || defined(CONFIG_440GRX) || \ + defined(CONFIG_460EX) || defined(CONFIG_460GT) +#define UART3_SDR SDR0_UART3 +#endif +#define MFREG(a, d) mfsdr(a, d) +#define MTREG(a, d) mtsdr(a, d) +#endif /* #if defined(CONFIG_440GP) */ +#elif defined(CONFIG_405EP) || defined(CONFIG_405EZ) +#define UCR0_MASK 0x0000007f +#define UCR1_MASK 0x00007f00 +#define UCR0_UDIV_POS 0 +#define UCR1_UDIV_POS 8 +#define UDIV_MAX 127 +#elif defined(CONFIG_405EX) +#define MFREG(a, d) mfsdr(a, d) +#define MTREG(a, d) mtsdr(a, d) +#define CR0_MASK 0x000000ff +#define CR0_EXTCLK_ENA 0x00800000 +#define CR0_UDIV_POS 0 +#define UDIV_SUBTRACT 0 +#define UART0_SDR SDR0_UART0 +#define UART1_SDR SDR0_UART1 +#else /* CONFIG_405GP || CONFIG_405CR */ +#define CR0_MASK 0x00001fff +#define CR0_EXTCLK_ENA 0x000000c0 +#define CR0_UDIV_POS 1 +#define UDIV_MAX 32 +#endif + +#if defined(CONFIG_405EP) && defined(CONFIG_SYS_EXT_SERIAL_CLOCK) +#error "External serial clock not supported on AMCC PPC405EP!" +#endif + +#if (defined(CONFIG_405EX) || defined(CONFIG_405EZ) || \ + defined(CONFIG_440)) && !defined(CONFIG_SYS_EXT_SERIAL_CLOCK) +/* + * For some SoC's, the cpu clock is on divider chain A, UART on + * divider chain B ... so cpu clock is irrelevant. Get the + * "optimized" values that are subject to the 1/2 opb clock + * constraint. + */ +static u16 serial_bdiv(int baudrate, u32 *udiv) +{ + sys_info_t sysinfo; + u32 div; /* total divisor udiv * bdiv */ + u32 umin; /* minimum udiv */ + u16 diff; /* smallest diff */ + u16 idiff; /* current diff */ + u16 ibdiv; /* current bdiv */ + u32 i; + u32 est; /* current estimate */ + u32 max; +#if defined(CONFIG_405EZ) + u32 cpr_pllc; + u32 plloutb; + u32 reg; +#endif + + get_sys_info(&sysinfo); + +#if defined(CONFIG_405EZ) + /* check the pll feedback source */ + mfcpr(CPR0_PLLC, cpr_pllc); + plloutb = ((CONFIG_SYS_CLK_FREQ * ((cpr_pllc & PLLC_SRC_MASK) ? + sysinfo.pllFwdDivB : sysinfo.pllFwdDiv) * + sysinfo.pllFbkDiv) / sysinfo.pllFwdDivB); + div = plloutb / (16 * baudrate); /* total divisor */ + umin = (plloutb / get_OPB_freq()) << 1; /* 2 x OPB divisor */ + max = 256; /* highest possible */ +#else /* 405EZ */ + div = sysinfo.freqPLB / (16 * baudrate); /* total divisor */ + umin = sysinfo.pllOpbDiv << 1; /* 2 x OPB divisor */ + max = 32; /* highest possible */ +#endif /* 405EZ */ + + *udiv = diff = max; + + /* + * i is the test udiv value -- start with the largest + * possible (max) to minimize serial clock and constrain + * search to umin. + */ + for (i = max; i > umin; i--) { + ibdiv = div / i; + est = i * ibdiv; + idiff = (est > div) ? (est - div) : (div - est); + if (idiff == 0) { + *udiv = i; + break; /* can't do better */ + } else if (idiff < diff) { + *udiv = i; /* best so far */ + diff = idiff; /* update lowest diff*/ + } + } + +#if defined(CONFIG_405EZ) + mfcpr(CPR0_PERD0, reg); + reg &= ~0x0000ffff; + reg |= ((*udiv - 0) << 8) | (*udiv - 0); + mtcpr(CPR0_PERD0, reg); +#endif + + return div / *udiv; +} +#endif /* #if (defined(CONFIG_405EP) ... */ + +/* + * This function returns the UART clock used by the common + * NS16550 driver. Additionally the SoC internal divisors for + * optimal UART baudrate are configured. + */ +int get_serial_clock(void) +{ + u32 clk; + u32 udiv; +#if !defined(CONFIG_405EZ) + u32 reg; +#endif +#if !defined(CONFIG_SYS_EXT_SERIAL_CLOCK) + PPC4xx_SYS_INFO sys_info; +#endif + + /* + * Programming of the internal divisors is SoC specific. + * Let's handle this in some #ifdef's for the SoC's. + */ + +#if defined(CONFIG_405CR) || defined(CONFIG_405GP) + reg = mfdcr(CPC0_CR0) & ~CR0_MASK; +#ifdef CONFIG_SYS_EXT_SERIAL_CLOCK + clk = CONFIG_SYS_EXT_SERIAL_CLOCK; + udiv = 1; + reg |= CR0_EXTCLK_ENA; +#else /* CONFIG_SYS_EXT_SERIAL_CLOCK */ + clk = gd->cpu_clk; +#ifdef CONFIG_SYS_405_UART_ERRATA_59 + udiv = 31; /* Errata 59: stuck at 31 */ +#else /* CONFIG_SYS_405_UART_ERRATA_59 */ + { + u32 tmp = CONFIG_SYS_BASE_BAUD * 16; + + udiv = (clk + tmp / 2) / tmp; + } + if (udiv > UDIV_MAX) /* max. n bits for udiv */ + udiv = UDIV_MAX; +#endif /* CONFIG_SYS_405_UART_ERRATA_59 */ +#endif /* CONFIG_SYS_EXT_SERIAL_CLOCK */ + reg |= (udiv - 1) << CR0_UDIV_POS; /* set the UART divisor */ + mtdcr (CPC0_CR0, reg); +#ifdef CONFIG_SYS_EXT_SERIAL_CLOCK + clk = CONFIG_SYS_EXT_SERIAL_CLOCK; +#else + clk = CONFIG_SYS_BASE_BAUD * 16; +#endif +#endif /* CONFIG_405CR */ + +#if defined(CONFIG_405EP) + { + u32 tmp = CONFIG_SYS_BASE_BAUD * 16; + + reg = mfdcr(CPC0_UCR) & ~(UCR0_MASK | UCR1_MASK); + clk = gd->cpu_clk; + udiv = (clk + tmp / 2) / tmp; + if (udiv > UDIV_MAX) /* max. n bits for udiv */ + udiv = UDIV_MAX; + } + reg |= udiv << UCR0_UDIV_POS; /* set the UART divisor */ + reg |= udiv << UCR1_UDIV_POS; /* set the UART divisor */ + mtdcr(CPC0_UCR, reg); + clk = CONFIG_SYS_BASE_BAUD * 16; +#endif /* CONFIG_405EP */ + +#if defined(CONFIG_405EX) || defined(CONFIG_440) + MFREG(UART0_SDR, reg); + reg &= ~CR0_MASK; + +#ifdef CONFIG_SYS_EXT_SERIAL_CLOCK + reg |= CR0_EXTCLK_ENA; + udiv = 1; + clk = CONFIG_SYS_EXT_SERIAL_CLOCK; +#else /* CONFIG_SYS_EXT_SERIAL_CLOCK */ + clk = gd->baudrate * serial_bdiv(gd->baudrate, &udiv) * 16; +#endif /* CONFIG_SYS_EXT_SERIAL_CLOCK */ + + reg |= (udiv - UDIV_SUBTRACT) << CR0_UDIV_POS; /* set the UART divisor */ + + /* + * Configure input clock to baudrate generator for all + * available serial ports here + */ + MTREG(UART0_SDR, reg); +#if defined(UART1_SDR) + MTREG(UART1_SDR, reg); +#endif +#if defined(UART2_SDR) + MTREG(UART2_SDR, reg); +#endif +#if defined(UART3_SDR) + MTREG(UART3_SDR, reg); +#endif +#endif /* CONFIG_405EX ... */ + +#if defined(CONFIG_405EZ) + clk = gd->baudrate * serial_bdiv(gd->baudrate, &udiv) * 16; +#endif /* CONFIG_405EZ */ + + /* + * Correct UART frequency in bd-info struct now that + * the UART divisor is available + */ +#ifdef CONFIG_SYS_EXT_SERIAL_CLOCK + gd->arch.uart_clk = CONFIG_SYS_EXT_SERIAL_CLOCK; +#else + get_sys_info(&sys_info); + gd->arch.uart_clk = sys_info.freqUART / udiv; +#endif + + return clk; +} +#endif /* CONFIG_405GP || CONFIG_405CR */ |
