u-boot/arch/powerpc/cpu/mpc8260/commproc.c
Scott Wood a166fbca20 powerpc: fix 8xx and 82xx type-punning warnings with GCC 4.7
C99's strict aliasing rules are insane to use in low-level code such as a
bootloader, but as Wolfgang has rejected -fno-strict-aliasing in the
past, add a union so that 16-bit accesses can be performed.

Compile-tested only.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Acked-by: Wolfgang Denk <wd@denx.de>
2013-06-11 22:01:45 +02:00

178 lines
4.4 KiB
C

/*
* This file is based on "arch/powerpc/8260_io/commproc.c" - here is it's
* copyright notice:
*
* General Purpose functions for the global management of the
* 8260 Communication Processor Module.
* Copyright (c) 1999 Dan Malek (dmalek@jlc.net)
* Copyright (c) 2000 MontaVista Software, Inc (source@mvista.com)
* 2.3.99 Updates
*
* In addition to the individual control of the communication
* channels, there are a few functions that globally affect the
* communication processor.
*
* Buffer descriptors must be allocated from the dual ported memory
* space. The allocator for that is here. When the communication
* process is reset, we reclaim the memory available. There is
* currently no deallocator for this memory.
*/
#include <common.h>
#include <asm/cpm_8260.h>
DECLARE_GLOBAL_DATA_PTR;
void
m8260_cpm_reset(void)
{
volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
volatile ulong count;
/* Reclaim the DP memory for our use.
*/
gd->arch.dp_alloc_base = CPM_DATAONLY_BASE;
gd->arch.dp_alloc_top = gd->arch.dp_alloc_base + CPM_DATAONLY_SIZE;
/*
* Reset CPM
*/
immr->im_cpm.cp_cpcr = CPM_CR_RST;
count = 0;
do { /* Spin until command processed */
__asm__ __volatile__ ("eieio");
} while ((immr->im_cpm.cp_cpcr & CPM_CR_FLG) && ++count < 1000000);
#ifdef CONFIG_HARD_I2C
immr->im_dprambase16[PROFF_I2C_BASE / sizeof(u16)] = 0;
#endif
}
/* Allocate some memory from the dual ported ram.
* To help protocols with object alignment restrictions, we do that
* if they ask.
*/
uint
m8260_cpm_dpalloc(uint size, uint align)
{
volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
uint retloc;
uint align_mask, off;
uint savebase;
align_mask = align - 1;
savebase = gd->arch.dp_alloc_base;
off = gd->arch.dp_alloc_base & align_mask;
if (off != 0)
gd->arch.dp_alloc_base += (align - off);
if ((off = size & align_mask) != 0)
size += align - off;
if ((gd->arch.dp_alloc_base + size) >= gd->arch.dp_alloc_top) {
gd->arch.dp_alloc_base = savebase;
panic("m8260_cpm_dpalloc: ran out of dual port ram!");
}
retloc = gd->arch.dp_alloc_base;
gd->arch.dp_alloc_base += size;
memset((void *)&immr->im_dprambase[retloc], 0, size);
return(retloc);
}
/* We also own one page of host buffer space for the allocation of
* UART "fifos" and the like.
*/
uint
m8260_cpm_hostalloc(uint size, uint align)
{
/* the host might not even have RAM yet - just use dual port RAM */
return (m8260_cpm_dpalloc(size, align));
}
/* Set a baud rate generator. This needs lots of work. There are
* eight BRGs, which can be connected to the CPM channels or output
* as clocks. The BRGs are in two different block of internal
* memory mapped space.
* The baud rate clock is the system clock divided by something.
* It was set up long ago during the initial boot phase and is
* is given to us.
* Baud rate clocks are zero-based in the driver code (as that maps
* to port numbers). Documentation uses 1-based numbering.
*/
#define BRG_INT_CLK gd->arch.brg_clk
#define BRG_UART_CLK (BRG_INT_CLK / 16)
/* This function is used by UARTs, or anything else that uses a 16x
* oversampled clock.
*/
void
m8260_cpm_setbrg(uint brg, uint rate)
{
volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
volatile uint *bp;
uint cd = BRG_UART_CLK / rate;
if ((BRG_UART_CLK % rate) < (rate / 2))
cd--;
if (brg < 4) {
bp = (uint *)&immr->im_brgc1;
}
else {
bp = (uint *)&immr->im_brgc5;
brg -= 4;
}
bp += brg;
*bp = (cd << 1) | CPM_BRG_EN;
}
/* This function is used to set high speed synchronous baud rate
* clocks.
*/
void
m8260_cpm_fastbrg(uint brg, uint rate, int div16)
{
volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
volatile uint *bp;
/* This is good enough to get SMCs running.....
*/
if (brg < 4) {
bp = (uint *)&immr->im_brgc1;
}
else {
bp = (uint *)&immr->im_brgc5;
brg -= 4;
}
bp += brg;
*bp = (((((BRG_INT_CLK+rate-1)/rate)-1)&0xfff)<<1)|CPM_BRG_EN;
if (div16)
*bp |= CPM_BRG_DIV16;
}
/* This function is used to set baud rate generators using an external
* clock source and 16x oversampling.
*/
void
m8260_cpm_extcbrg(uint brg, uint rate, uint extclk, int pinsel)
{
volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
volatile uint *bp;
if (brg < 4) {
bp = (uint *)&immr->im_brgc1;
}
else {
bp = (uint *)&immr->im_brgc5;
brg -= 4;
}
bp += brg;
*bp = ((((((extclk/16)+rate-1)/rate)-1)&0xfff)<<1)|CPM_BRG_EN;
if (pinsel == 0)
*bp |= CPM_BRG_EXTC_CLK3_9;
else
*bp |= CPM_BRG_EXTC_CLK5_15;
}