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ARM: at91: add pmc DT support

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Specified the main Oscillator via clock binding.
This will allow to do not hardcode it anymore in the DT board at 12MHz.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
This commit is contained in:
Jean-Christophe PLAGNIOL-VILLARD
2012-03-02 20:44:23 +08:00
parent 2b11ea5bf2
commit eb5e76ffd4
10 changed files with 112 additions and 7 deletions
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56
arch/arm/mach-at91/clock.c
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@@ -23,6 +23,7 @@
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/of_address.h>
#include <mach/hardware.h>
#include <mach/at91_pmc.h>
@@ -671,16 +672,12 @@ static void __init at91_upll_usbfs_clock_init(unsigned long main_clock)
uhpck.rate_hz /= 1 + ((at91_pmc_read(AT91_PMC_USB) & AT91_PMC_OHCIUSBDIV) >> 8);
}
int __init at91_clock_init(unsigned long main_clock)
static int __init at91_pmc_init(unsigned long main_clock)
{
unsigned tmp, freq, mckr;
int i;
int pll_overclock = false;
at91_pmc_base = ioremap(AT91_PMC, 256);
if (!at91_pmc_base)
panic("Impossible to ioremap AT91_PMC 0x%x\n", AT91_PMC);
/*
* When the bootloader initialized the main oscillator correctly,
* there's no problem using the cycle counter. But if it didn't,
@@ -802,6 +799,55 @@ int __init at91_clock_init(unsigned long main_clock)
return 0;
}
#if defined(CONFIG_OF)
static struct of_device_id pmc_ids[] = {
{ .compatible = "atmel,at91rm9200-pmc" },
{ /*sentinel*/ }
};
static struct of_device_id osc_ids[] = {
{ .compatible = "atmel,osc" },
{ /*sentinel*/ }
};
int __init at91_dt_clock_init(void)
{
struct device_node *np;
u32 main_clock = 0;
np = of_find_matching_node(NULL, pmc_ids);
if (!np)
panic("unable to find compatible pmc node in dtb\n");
at91_pmc_base = of_iomap(np, 0);
if (!at91_pmc_base)
panic("unable to map pmc cpu registers\n");
of_node_put(np);
/* retrieve the freqency of fixed clocks from device tree */
np = of_find_matching_node(NULL, osc_ids);
if (np) {
u32 rate;
if (!of_property_read_u32(np, "clock-frequency", &rate))
main_clock = rate;
}
of_node_put(np);
return at91_pmc_init(main_clock);
}
#endif
int __init at91_clock_init(unsigned long main_clock)
{
at91_pmc_base = ioremap(AT91_PMC, 256);
if (!at91_pmc_base)
panic("Impossible to ioremap AT91_PMC 0x%x\n", AT91_PMC);
return at91_pmc_init(main_clock);
}
/*
* Several unused clocks may be active. Turn them off.
*/