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- Obtain main clock frequency dynamically based on CKGR_MCFR register

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contents.
- It is possible to override the dynamic configuration by using
  AT91C_MAIN_CLOCK option in kernel config.

PR:		arm/128961 (based on)
Submitted by:	Bjorn Konig <bkoenig@alpha-tierchen.de>
Reviewed by:	imp
Approved by:	kib (mentor, implicit)
This commit is contained in:
stas 2008-11-30 22:33:03 +00:00
parent ef1cb4c265
commit 610e0aa6be
2 changed files with 52 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

58
sys/arm/at91/at91_pmc.c
View File

@ -31,6 +31,7 @@ __FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/limits.h>
#include <sys/module.h>
#include <sys/time.h>
#include <sys/bus.h>
@ -54,7 +55,7 @@ static struct at91_pmc_softc {
bus_space_handle_t sc_sh;
struct resource *mem_res; /* Memory resource */
device_t dev;
int main_clock_hz;
unsigned int main_clock_hz;
uint32_t pllb_init;
} *pmc_softc;
@ -145,6 +146,18 @@ static struct at91_pmc_clock *const clock_list[] = {
&ohci_clk
};
#if !defined(AT91C_MAIN_CLOCK)
static const unsigned int at91_mainf_tbl[] = {
3000000, 3276800, 3686400, 3840000, 4000000,
4433619, 4915200, 5000000, 5242880, 6000000,
6144000, 6400000, 6553600, 7159090, 7372800,
7864320, 8000000, 9830400, 10000000, 11059200,
12000000, 12288000, 13560000, 14318180, 14745600,
16000000, 17344700, 18432000, 20000000
};
#define MAINF_TBL_LEN (sizeof(at91_mainf_tbl) / sizeof(*at91_mainf_tbl))
#endif
static inline uint32_t
RD4(struct at91_pmc_softc *sc, bus_size_t off)
{
@ -301,7 +314,7 @@ at91_pmc_pll_calc(uint32_t main_freq, uint32_t out_freq)
}
static void
at91_pmc_init_clock(struct at91_pmc_softc *sc, int main_clock)
at91_pmc_init_clock(struct at91_pmc_softc *sc, unsigned int main_clock)
{
uint32_t mckr;
int freq;
@ -384,21 +397,52 @@ at91_pmc_probe(device_t dev)
return (0);
}
#if !defined(AT91C_MAIN_CLOCK)
static unsigned int
at91_pmc_sense_mainf(struct at91_pmc_softc *sc)
{
unsigned int ckgr_val;
unsigned int diff, matchdiff;
int i, match;
ckgr_val = (RD4(sc, CKGR_MCFR) & CKGR_MCFR_MAINF_MASK) << 11;
/*
* Try to find the standard frequency that match best.
*/
match = 0;
matchdiff = abs(ckgr_val - at91_mainf_tbl[0]);
for (i = 1; i < MAINF_TBL_LEN; i++) {
diff = abs(ckgr_val - at91_mainf_tbl[i]);
if (diff < matchdiff) {
match = i;
matchdiff = diff;
}
}
return (at91_mainf_tbl[match]);
}
#endif
static int
at91_pmc_attach(device_t dev)
{
unsigned int mainf;
int err;
pmc_softc = device_get_softc(dev);
pmc_softc->dev = dev;
if ((err = at91_pmc_activate(dev)) != 0)
return err;
#if defined(AT91_TSC) | defined (AT91_BWCT)
at91_pmc_init_clock(pmc_softc, 16000000);
#else
at91_pmc_init_clock(pmc_softc, 10000000);
#endif
/*
* Configure main clock frequency.
*/
#if !defined(AT91C_MAIN_CLOCK)
mainf = at91_pmc_sense_mainf(pmc_softc);
#else
mainf = AT91C_MAIN_CLOCK;
#endif
at91_pmc_init_clock(pmc_softc, mainf);
return (0);
}

1
sys/conf/options.arm
View File

@ -5,6 +5,7 @@ ARMFPE opt_global.h
ARM_KERN_DIRECTMAP opt_vm.h
ARM_USE_SMALL_ALLOC opt_global.h
AT91C_MASTER_CLOCK opt_global.h
AT91C_MAIN_CLOCK opt_at91.h
COUNTS_PER_SEC opt_timer.h
CPU_SA1100 opt_global.h
CPU_SA1110 opt_global.h