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ARM: OMAP1: Update dpll1 default rate reprogramming method
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According to comments in omap1_select_table_rate(), reprogramming dpll1
is tricky, and should always be done from SRAM.

While being at it, move OMAP730 special case handling inside
omap_sram_reprogram_clock().

Created on top of version 2 of the series "ARM: OMAP1: Fix dpll1
reprogramming related issues", which it depends on.
Tested on Amstrad Delta.

Signed-off-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Signed-off-by: Tony Lindgren <tony@atomide.com>
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Janusz Krzysztofik authored and Tony Lindgren committed Dec 9, 2011
1 parent 24ce270 commit f9e5908
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Showing 3 changed files with 9 additions and 7 deletions.
6 changes: 1 addition & 5 deletions arch/arm/mach-omap1/clock.c
Original file line number Diff line number Diff line change
Expand Up @@ -218,12 +218,8 @@ int omap1_select_table_rate(struct clk *clk, unsigned long rate)
/*
* In most cases we should not need to reprogram DPLL.
* Reprogramming the DPLL is tricky, it must be done from SRAM.
* (on 730, bit 13 must always be 1)
*/
if (cpu_is_omap7xx())
omap_sram_reprogram_clock(ptr->dpllctl_val, ptr->ckctl_val | 0x2000);
else
omap_sram_reprogram_clock(ptr->dpllctl_val, ptr->ckctl_val);
omap_sram_reprogram_clock(ptr->dpllctl_val, ptr->ckctl_val);

/* XXX Do we need to recalculate the tree below DPLL1 at this point? */
ck_dpll1_p->rate = ptr->pll_rate;
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7 changes: 5 additions & 2 deletions arch/arm/mach-omap1/clock_data.c
Original file line number Diff line number Diff line change
Expand Up @@ -25,6 +25,7 @@
#include <plat/clock.h>
#include <plat/cpu.h>
#include <plat/clkdev_omap.h>
#include <plat/sram.h> /* for omap_sram_reprogram_clock() */
#include <plat/usb.h> /* for OTG_BASE */

#include "clock.h"
Expand Down Expand Up @@ -944,8 +945,10 @@ void __init omap1_clk_late_init(void)
/* Find the highest supported frequency and enable it */
if (omap1_select_table_rate(&virtual_ck_mpu, ~0)) {
pr_err("System frequencies not set, using default. Check your config.\n");
omap_writew(0x2290, DPLL_CTL);
omap_writew(cpu_is_omap7xx() ? 0x2005 : 0x0005, ARM_CKCTL);
/*
* Reprogramming the DPLL is tricky, it must be done from SRAM.
*/
omap_sram_reprogram_clock(0x2290, 0x0005);
ck_dpll1.rate = OMAP1_DPLL1_SANE_VALUE;
}
propagate_rate(&ck_dpll1);
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3 changes: 3 additions & 0 deletions arch/arm/plat-omap/sram.c
Original file line number Diff line number Diff line change
Expand Up @@ -222,6 +222,9 @@ static void (*_omap_sram_reprogram_clock)(u32 dpllctl, u32 ckctl);
void omap_sram_reprogram_clock(u32 dpllctl, u32 ckctl)
{
BUG_ON(!_omap_sram_reprogram_clock);
/* On 730, bit 13 must always be 1 */
if (cpu_is_omap7xx())
ckctl |= 0x2000;
_omap_sram_reprogram_clock(dpllctl, ckctl);
}

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