1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Au1300 media block power gating (VSS) 4 * 5 * This is a stop-gap solution until I have the clock framework integration 6 * ready. This stuff here really must be handled transparently when clocks 7 * for various media blocks are enabled/disabled. 8 */ 9 10 #include <linux/export.h> 11 #include <linux/spinlock.h> 12 #include <asm/mach-au1x00/au1000.h> 13 14 #define VSS_GATE 0x00 /* gate wait timers */ 15 #define VSS_CLKRST 0x04 /* clock/block control */ 16 #define VSS_FTR 0x08 /* footers */ 17 18 #define VSS_ADDR(blk) (KSEG1ADDR(AU1300_VSS_PHYS_ADDR) + (blk * 0x0c)) 19 20 static DEFINE_SPINLOCK(au1300_vss_lock); 21 22 /* enable a block as outlined in the databook */ 23 static inline void __enable_block(int block) 24 { 25 void __iomem *base = (void __iomem *)VSS_ADDR(block); 26 27 __raw_writel(3, base + VSS_CLKRST); /* enable clock, assert reset */ 28 wmb(); 29 30 __raw_writel(0x01fffffe, base + VSS_GATE); /* maximum setup time */ 31 wmb(); 32 33 /* enable footers in sequence */ 34 __raw_writel(0x01, base + VSS_FTR); 35 wmb(); 36 __raw_writel(0x03, base + VSS_FTR); 37 wmb(); 38 __raw_writel(0x07, base + VSS_FTR); 39 wmb(); 40 __raw_writel(0x0f, base + VSS_FTR); 41 wmb(); 42 43 __raw_writel(0x01ffffff, base + VSS_GATE); /* start FSM too */ 44 wmb(); 45 46 __raw_writel(2, base + VSS_CLKRST); /* deassert reset */ 47 wmb(); 48 49 __raw_writel(0x1f, base + VSS_FTR); /* enable isolation cells */ 50 wmb(); 51 } 52 53 /* disable a block as outlined in the databook */ 54 static inline void __disable_block(int block) 55 { 56 void __iomem *base = (void __iomem *)VSS_ADDR(block); 57 58 __raw_writel(0x0f, base + VSS_FTR); /* disable isolation cells */ 59 wmb(); 60 __raw_writel(0, base + VSS_GATE); /* disable FSM */ 61 wmb(); 62 __raw_writel(3, base + VSS_CLKRST); /* assert reset */ 63 wmb(); 64 __raw_writel(1, base + VSS_CLKRST); /* disable clock */ 65 wmb(); 66 __raw_writel(0, base + VSS_FTR); /* disable all footers */ 67 wmb(); 68 } 69 70 void au1300_vss_block_control(int block, int enable) 71 { 72 unsigned long flags; 73 74 if (alchemy_get_cputype() != ALCHEMY_CPU_AU1300) 75 return; 76 77 /* only one block at a time */ 78 spin_lock_irqsave(&au1300_vss_lock, flags); 79 if (enable) 80 __enable_block(block); 81 else 82 __disable_block(block); 83 spin_unlock_irqrestore(&au1300_vss_lock, flags); 84 } 85 EXPORT_SYMBOL_GPL(au1300_vss_block_control); 86