linux/arch/mips/alchemy/common/vss.c

85 lines
2.2 KiB
C

/*
* Au1300 media block power gating (VSS)
*
* This is a stop-gap solution until I have the clock framework integration
* ready. This stuff here really must be handled transparently when clocks
* for various media blocks are enabled/disabled.
*/
#include <linux/module.h>
#include <linux/spinlock.h>
#include <asm/mach-au1x00/au1000.h>
#define VSS_GATE 0x00 /* gate wait timers */
#define VSS_CLKRST 0x04 /* clock/block control */
#define VSS_FTR 0x08 /* footers */
#define VSS_ADDR(blk) (KSEG1ADDR(AU1300_VSS_PHYS_ADDR) + (blk * 0x0c))
static DEFINE_SPINLOCK(au1300_vss_lock);
/* enable a block as outlined in the databook */
static inline void __enable_block(int block)
{
void __iomem *base = (void __iomem *)VSS_ADDR(block);
__raw_writel(3, base + VSS_CLKRST); /* enable clock, assert reset */
wmb();
__raw_writel(0x01fffffe, base + VSS_GATE); /* maximum setup time */
wmb();
/* enable footers in sequence */
__raw_writel(0x01, base + VSS_FTR);
wmb();
__raw_writel(0x03, base + VSS_FTR);
wmb();
__raw_writel(0x07, base + VSS_FTR);
wmb();
__raw_writel(0x0f, base + VSS_FTR);
wmb();
__raw_writel(0x01ffffff, base + VSS_GATE); /* start FSM too */
wmb();
__raw_writel(2, base + VSS_CLKRST); /* deassert reset */
wmb();
__raw_writel(0x1f, base + VSS_FTR); /* enable isolation cells */
wmb();
}
/* disable a block as outlined in the databook */
static inline void __disable_block(int block)
{
void __iomem *base = (void __iomem *)VSS_ADDR(block);
__raw_writel(0x0f, base + VSS_FTR); /* disable isolation cells */
wmb();
__raw_writel(0, base + VSS_GATE); /* disable FSM */
wmb();
__raw_writel(3, base + VSS_CLKRST); /* assert reset */
wmb();
__raw_writel(1, base + VSS_CLKRST); /* disable clock */
wmb();
__raw_writel(0, base + VSS_FTR); /* disable all footers */
wmb();
}
void au1300_vss_block_control(int block, int enable)
{
unsigned long flags;
if (alchemy_get_cputype() != ALCHEMY_CPU_AU1300)
return;
/* only one block at a time */
spin_lock_irqsave(&au1300_vss_lock, flags);
if (enable)
__enable_block(block);
else
__disable_block(block);
spin_unlock_irqrestore(&au1300_vss_lock, flags);
}
EXPORT_SYMBOL_GPL(au1300_vss_block_control);