86 lines
2.2 KiB
C
86 lines
2.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Au1300 media block power gating (VSS)
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*
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* This is a stop-gap solution until I have the clock framework integration
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* ready. This stuff here really must be handled transparently when clocks
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* for various media blocks are enabled/disabled.
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*/
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#include <linux/export.h>
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#include <linux/spinlock.h>
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#include <asm/mach-au1x00/au1000.h>
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#define VSS_GATE 0x00 /* gate wait timers */
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#define VSS_CLKRST 0x04 /* clock/block control */
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#define VSS_FTR 0x08 /* footers */
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#define VSS_ADDR(blk) (KSEG1ADDR(AU1300_VSS_PHYS_ADDR) + (blk * 0x0c))
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static DEFINE_SPINLOCK(au1300_vss_lock);
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/* enable a block as outlined in the databook */
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static inline void __enable_block(int block)
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{
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void __iomem *base = (void __iomem *)VSS_ADDR(block);
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__raw_writel(3, base + VSS_CLKRST); /* enable clock, assert reset */
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wmb();
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__raw_writel(0x01fffffe, base + VSS_GATE); /* maximum setup time */
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wmb();
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/* enable footers in sequence */
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__raw_writel(0x01, base + VSS_FTR);
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wmb();
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__raw_writel(0x03, base + VSS_FTR);
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wmb();
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__raw_writel(0x07, base + VSS_FTR);
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wmb();
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__raw_writel(0x0f, base + VSS_FTR);
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wmb();
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__raw_writel(0x01ffffff, base + VSS_GATE); /* start FSM too */
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wmb();
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__raw_writel(2, base + VSS_CLKRST); /* deassert reset */
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wmb();
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__raw_writel(0x1f, base + VSS_FTR); /* enable isolation cells */
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wmb();
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}
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/* disable a block as outlined in the databook */
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static inline void __disable_block(int block)
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{
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void __iomem *base = (void __iomem *)VSS_ADDR(block);
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__raw_writel(0x0f, base + VSS_FTR); /* disable isolation cells */
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wmb();
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__raw_writel(0, base + VSS_GATE); /* disable FSM */
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wmb();
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__raw_writel(3, base + VSS_CLKRST); /* assert reset */
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wmb();
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__raw_writel(1, base + VSS_CLKRST); /* disable clock */
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wmb();
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__raw_writel(0, base + VSS_FTR); /* disable all footers */
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wmb();
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}
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void au1300_vss_block_control(int block, int enable)
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{
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unsigned long flags;
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if (alchemy_get_cputype() != ALCHEMY_CPU_AU1300)
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return;
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/* only one block at a time */
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spin_lock_irqsave(&au1300_vss_lock, flags);
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if (enable)
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__enable_block(block);
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else
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__disable_block(block);
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spin_unlock_irqrestore(&au1300_vss_lock, flags);
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}
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EXPORT_SYMBOL_GPL(au1300_vss_block_control);
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