alistair23-linux/arch/powerpc/sysdev/cpm2_common.c
Scott Wood 83fcdb4b35 [POWERPC] cpm2: Fix off-by-one error in setbrg().
The hardware adds one to the BRG value to get the divider, so it must
be subtracted by software.  Without this patch, characters will occasionally
be corrupted.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2007-09-10 16:02:09 -05:00

309 lines
7.4 KiB
C

/*
* General Purpose functions for the global management of the
* 8260 Communication Processor Module.
* Copyright (c) 1999-2001 Dan Malek <dan@embeddedalley.com>
* Copyright (c) 2000 MontaVista Software, Inc (source@mvista.com)
* 2.3.99 Updates
*
* 2006 (c) MontaVista Software, Inc.
* Vitaly Bordug <vbordug@ru.mvista.com>
* Merged to arch/powerpc from arch/ppc/syslib/cpm2_common.c
*
* This file is licensed under the terms of the GNU General Public License
* version 2. This program is licensed "as is" without any warranty of any
* kind, whether express or implied.
*/
/*
*
* 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 <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/param.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/mpc8260.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/cpm2.h>
#include <asm/rheap.h>
#include <asm/fs_pd.h>
#include <sysdev/fsl_soc.h>
static void cpm2_dpinit(void);
cpm_cpm2_t *cpmp; /* Pointer to comm processor space */
/* We allocate this here because it is used almost exclusively for
* the communication processor devices.
*/
cpm2_map_t *cpm2_immr;
intctl_cpm2_t *cpm2_intctl;
#define CPM_MAP_SIZE (0x40000) /* 256k - the PQ3 reserve this amount
of space for CPM as it is larger
than on PQ2 */
void
cpm2_reset(void)
{
cpm2_immr = (cpm2_map_t *)ioremap(CPM_MAP_ADDR, CPM_MAP_SIZE);
cpm2_intctl = cpm2_map(im_intctl);
/* Reclaim the DP memory for our use.
*/
cpm2_dpinit();
/* Tell everyone where the comm processor resides.
*/
cpmp = &cpm2_immr->im_cpm;
}
/* 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 (get_brgfreq())
#define BRG_UART_CLK (BRG_INT_CLK/16)
/* This function is used by UARTS, or anything else that uses a 16x
* oversampled clock.
*/
void
cpm_setbrg(uint brg, uint rate)
{
volatile uint *bp;
/* This is good enough to get SMCs running.....
*/
if (brg < 4) {
bp = cpm2_map_size(im_brgc1, 16);
} else {
bp = cpm2_map_size(im_brgc5, 16);
brg -= 4;
}
bp += brg;
out_be32(bp, (((BRG_UART_CLK / rate) - 1) << 1) | CPM_BRG_EN);
cpm2_unmap(bp);
}
/* This function is used to set high speed synchronous baud rate
* clocks.
*/
void
cpm2_fastbrg(uint brg, uint rate, int div16)
{
volatile uint *bp;
if (brg < 4) {
bp = cpm2_map_size(im_brgc1, 16);
}
else {
bp = cpm2_map_size(im_brgc5, 16);
brg -= 4;
}
bp += brg;
*bp = ((BRG_INT_CLK / rate) << 1) | CPM_BRG_EN;
if (div16)
*bp |= CPM_BRG_DIV16;
cpm2_unmap(bp);
}
int cpm2_clk_setup(enum cpm_clk_target target, int clock, int mode)
{
int ret = 0;
int shift;
int i, bits = 0;
cpmux_t *im_cpmux;
u32 *reg;
u32 mask = 7;
u8 clk_map [24][3] = {
{CPM_CLK_FCC1, CPM_BRG5, 0},
{CPM_CLK_FCC1, CPM_BRG6, 1},
{CPM_CLK_FCC1, CPM_BRG7, 2},
{CPM_CLK_FCC1, CPM_BRG8, 3},
{CPM_CLK_FCC1, CPM_CLK9, 4},
{CPM_CLK_FCC1, CPM_CLK10, 5},
{CPM_CLK_FCC1, CPM_CLK11, 6},
{CPM_CLK_FCC1, CPM_CLK12, 7},
{CPM_CLK_FCC2, CPM_BRG5, 0},
{CPM_CLK_FCC2, CPM_BRG6, 1},
{CPM_CLK_FCC2, CPM_BRG7, 2},
{CPM_CLK_FCC2, CPM_BRG8, 3},
{CPM_CLK_FCC2, CPM_CLK13, 4},
{CPM_CLK_FCC2, CPM_CLK14, 5},
{CPM_CLK_FCC2, CPM_CLK15, 6},
{CPM_CLK_FCC2, CPM_CLK16, 7},
{CPM_CLK_FCC3, CPM_BRG5, 0},
{CPM_CLK_FCC3, CPM_BRG6, 1},
{CPM_CLK_FCC3, CPM_BRG7, 2},
{CPM_CLK_FCC3, CPM_BRG8, 3},
{CPM_CLK_FCC3, CPM_CLK13, 4},
{CPM_CLK_FCC3, CPM_CLK14, 5},
{CPM_CLK_FCC3, CPM_CLK15, 6},
{CPM_CLK_FCC3, CPM_CLK16, 7}
};
im_cpmux = cpm2_map(im_cpmux);
switch (target) {
case CPM_CLK_SCC1:
reg = &im_cpmux->cmx_scr;
shift = 24;
case CPM_CLK_SCC2:
reg = &im_cpmux->cmx_scr;
shift = 16;
break;
case CPM_CLK_SCC3:
reg = &im_cpmux->cmx_scr;
shift = 8;
break;
case CPM_CLK_SCC4:
reg = &im_cpmux->cmx_scr;
shift = 0;
break;
case CPM_CLK_FCC1:
reg = &im_cpmux->cmx_fcr;
shift = 24;
break;
case CPM_CLK_FCC2:
reg = &im_cpmux->cmx_fcr;
shift = 16;
break;
case CPM_CLK_FCC3:
reg = &im_cpmux->cmx_fcr;
shift = 8;
break;
default:
printk(KERN_ERR "cpm2_clock_setup: invalid clock target\n");
return -EINVAL;
}
if (mode == CPM_CLK_RX)
shift +=3;
for (i=0; i<24; i++) {
if (clk_map[i][0] == target && clk_map[i][1] == clock) {
bits = clk_map[i][2];
break;
}
}
if (i == sizeof(clk_map)/3)
ret = -EINVAL;
bits <<= shift;
mask <<= shift;
out_be32(reg, (in_be32(reg) & ~mask) | bits);
cpm2_unmap(im_cpmux);
return ret;
}
/*
* dpalloc / dpfree bits.
*/
static spinlock_t cpm_dpmem_lock;
/* 16 blocks should be enough to satisfy all requests
* until the memory subsystem goes up... */
static rh_block_t cpm_boot_dpmem_rh_block[16];
static rh_info_t cpm_dpmem_info;
static u8* im_dprambase;
static void cpm2_dpinit(void)
{
spin_lock_init(&cpm_dpmem_lock);
im_dprambase = ioremap(CPM_MAP_ADDR, CPM_DATAONLY_BASE + CPM_DATAONLY_SIZE);
/* initialize the info header */
rh_init(&cpm_dpmem_info, 1,
sizeof(cpm_boot_dpmem_rh_block) /
sizeof(cpm_boot_dpmem_rh_block[0]),
cpm_boot_dpmem_rh_block);
/* Attach the usable dpmem area */
/* XXX: This is actually crap. CPM_DATAONLY_BASE and
* CPM_DATAONLY_SIZE is only a subset of the available dpram. It
* varies with the processor and the microcode patches activated.
* But the following should be at least safe.
*/
rh_attach_region(&cpm_dpmem_info, CPM_DATAONLY_BASE, CPM_DATAONLY_SIZE);
}
/* This function returns an index into the DPRAM area.
*/
unsigned long cpm_dpalloc(uint size, uint align)
{
unsigned long start;
unsigned long flags;
spin_lock_irqsave(&cpm_dpmem_lock, flags);
cpm_dpmem_info.alignment = align;
start = rh_alloc(&cpm_dpmem_info, size, "commproc");
spin_unlock_irqrestore(&cpm_dpmem_lock, flags);
return (uint)start;
}
EXPORT_SYMBOL(cpm_dpalloc);
int cpm_dpfree(unsigned long offset)
{
int ret;
unsigned long flags;
spin_lock_irqsave(&cpm_dpmem_lock, flags);
ret = rh_free(&cpm_dpmem_info, offset);
spin_unlock_irqrestore(&cpm_dpmem_lock, flags);
return ret;
}
EXPORT_SYMBOL(cpm_dpfree);
/* not sure if this is ever needed */
unsigned long cpm_dpalloc_fixed(unsigned long offset, uint size, uint align)
{
unsigned long start;
unsigned long flags;
spin_lock_irqsave(&cpm_dpmem_lock, flags);
cpm_dpmem_info.alignment = align;
start = rh_alloc_fixed(&cpm_dpmem_info, offset, size, "commproc");
spin_unlock_irqrestore(&cpm_dpmem_lock, flags);
return start;
}
EXPORT_SYMBOL(cpm_dpalloc_fixed);
void cpm_dpdump(void)
{
rh_dump(&cpm_dpmem_info);
}
EXPORT_SYMBOL(cpm_dpdump);
void *cpm_dpram_addr(unsigned long offset)
{
return (void *)(im_dprambase + offset);
}
EXPORT_SYMBOL(cpm_dpram_addr);