--- /dev/null
+/*
+ * sh7372 lowlevel sleep code for "Core Standby Mode"
+ *
+ * Copyright (C) 2011 Magnus Damm
+ *
+ * In "Core Standby Mode" the ARM core is off, but L2 cache is still on
+ *
+ * Based on mach-omap2/sleep34xx.S
+ *
+ * (C) Copyright 2007 Texas Instruments
+ * Karthik Dasu <karthik-dp@ti.com>
+ *
+ * (C) Copyright 2004 Texas Instruments, <www.ti.com>
+ * Richard Woodruff <r-woodruff2@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR /PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+
+#define SMFRAM 0xe6a70000
+
+ .align
+kernel_flush:
+ .word v7_flush_dcache_all
+
+ .align 3
+ENTRY(sh7372_cpu_suspend)
+ stmfd sp!, {r0-r12, lr} @ save registers on stack
+
+ ldr r8, =SMFRAM
+
+ mov r4, sp @ Store sp
+ mrs r5, spsr @ Store spsr
+ mov r6, lr @ Store lr
+ stmia r8!, {r4-r6}
+
+ mrc p15, 0, r4, c1, c0, 2 @ Coprocessor access control register
+ mrc p15, 0, r5, c2, c0, 0 @ TTBR0
+ mrc p15, 0, r6, c2, c0, 1 @ TTBR1
+ mrc p15, 0, r7, c2, c0, 2 @ TTBCR
+ stmia r8!, {r4-r7}
+
+ mrc p15, 0, r4, c3, c0, 0 @ Domain access Control Register
+ mrc p15, 0, r5, c10, c2, 0 @ PRRR
+ mrc p15, 0, r6, c10, c2, 1 @ NMRR
+ stmia r8!,{r4-r6}
+
+ mrc p15, 0, r4, c13, c0, 1 @ Context ID
+ mrc p15, 0, r5, c13, c0, 2 @ User r/w thread and process ID
+ mrc p15, 0, r6, c12, c0, 0 @ Secure or NS vector base address
+ mrs r7, cpsr @ Store current cpsr
+ stmia r8!, {r4-r7}
+
+ mrc p15, 0, r4, c1, c0, 0 @ save control register
+ stmia r8!, {r4}
+
+ /*
+ * jump out to kernel flush routine
+ * - reuse that code is better
+ * - it executes in a cached space so is faster than refetch per-block
+ * - should be faster and will change with kernel
+ * - 'might' have to copy address, load and jump to it
+ * Flush all data from the L1 data cache before disabling
+ * SCTLR.C bit.
+ */
+ ldr r1, kernel_flush
+ mov lr, pc
+ bx r1
+
+ /*
+ * Clear the SCTLR.C bit to prevent further data cache
+ * allocation. Clearing SCTLR.C would make all the data accesses
+ * strongly ordered and would not hit the cache.
+ */
+ mrc p15, 0, r0, c1, c0, 0
+ bic r0, r0, #(1 << 2) @ Disable the C bit
+ mcr p15, 0, r0, c1, c0, 0
+ isb
+
+ /*
+ * Invalidate L1 data cache. Even though only invalidate is
+ * necessary exported flush API is used here. Doing clean
+ * on already clean cache would be almost NOP.
+ */
+ ldr r1, kernel_flush
+ blx r1
+ /*
+ * The kernel doesn't interwork: v7_flush_dcache_all in particluar will
+ * always return in Thumb state when CONFIG_THUMB2_KERNEL is enabled.
+ * This sequence switches back to ARM. Note that .align may insert a
+ * nop: bx pc needs to be word-aligned in order to work.
+ */
+ THUMB( .thumb )
+ THUMB( .align )
+ THUMB( bx pc )
+ THUMB( nop )
+ .arm
+
+ /* Data memory barrier and Data sync barrier */
+ dsb
+ dmb
+
+/*
+ * ===================================
+ * == WFI instruction => Enter idle ==
+ * ===================================
+ */
+ wfi @ wait for interrupt
+
+/*
+ * ===================================
+ * == Resume path for non-OFF modes ==
+ * ===================================
+ */
+ mrc p15, 0, r0, c1, c0, 0
+ tst r0, #(1 << 2) @ Check C bit enabled?
+ orreq r0, r0, #(1 << 2) @ Enable the C bit if cleared
+ mcreq p15, 0, r0, c1, c0, 0
+ isb
+
+/*
+ * ===================================
+ * == Exit point from non-OFF modes ==
+ * ===================================
+ */
+ ldmfd sp!, {r0-r12, pc} @ restore regs and return
+
+ .pool
+
+ .align 12
+ .text
+ .global sh7372_cpu_resume
+sh7372_cpu_resume:
+
+ mov r1, #0
+ /*
+ * Invalidate all instruction caches to PoU
+ * and flush branch target cache
+ */
+ mcr p15, 0, r1, c7, c5, 0
+
+ ldr r3, =SMFRAM
+
+ ldmia r3!, {r4-r6}
+ mov sp, r4 @ Restore sp
+ msr spsr_cxsf, r5 @ Restore spsr
+ mov lr, r6 @ Restore lr
+
+ ldmia r3!, {r4-r7}
+ mcr p15, 0, r4, c1, c0, 2 @ Coprocessor access Control Register
+ mcr p15, 0, r5, c2, c0, 0 @ TTBR0
+ mcr p15, 0, r6, c2, c0, 1 @ TTBR1
+ mcr p15, 0, r7, c2, c0, 2 @ TTBCR
+
+ ldmia r3!,{r4-r6}
+ mcr p15, 0, r4, c3, c0, 0 @ Domain access Control Register
+ mcr p15, 0, r5, c10, c2, 0 @ PRRR
+ mcr p15, 0, r6, c10, c2, 1 @ NMRR
+
+ ldmia r3!,{r4-r7}
+ mcr p15, 0, r4, c13, c0, 1 @ Context ID
+ mcr p15, 0, r5, c13, c0, 2 @ User r/w thread and process ID
+ mrc p15, 0, r6, c12, c0, 0 @ Secure or NS vector base address
+ msr cpsr, r7 @ store cpsr
+
+ /* Starting to enable MMU here */
+ mrc p15, 0, r7, c2, c0, 2 @ Read TTBRControl
+ /* Extract N (0:2) bits and decide whether to use TTBR0 or TTBR1 */
+ and r7, #0x7
+ cmp r7, #0x0
+ beq usettbr0
+ttbr_error:
+ /*
+ * More work needs to be done to support N[0:2] value other than 0
+ * So looping here so that the error can be detected
+ */
+ b ttbr_error
+
+ .align
+cache_pred_disable_mask:
+ .word 0xFFFFE7FB
+ttbrbit_mask:
+ .word 0xFFFFC000
+table_index_mask:
+ .word 0xFFF00000
+table_entry:
+ .word 0x00000C02
+usettbr0:
+
+ mrc p15, 0, r2, c2, c0, 0
+ ldr r5, ttbrbit_mask
+ and r2, r5
+ mov r4, pc
+ ldr r5, table_index_mask
+ and r4, r5 @ r4 = 31 to 20 bits of pc
+ /* Extract the value to be written to table entry */
+ ldr r6, table_entry
+ /* r6 has the value to be written to table entry */
+ add r6, r6, r4
+ /* Getting the address of table entry to modify */
+ lsr r4, #18
+ /* r2 has the location which needs to be modified */
+ add r2, r4
+ ldr r4, [r2]
+ str r6, [r2] /* modify the table entry */
+
+ mov r7, r6
+ mov r5, r2
+ mov r6, r4
+ /* r5 = original page table address */
+ /* r6 = original page table data */
+
+ mov r0, #0
+ mcr p15, 0, r0, c7, c5, 4 @ Flush prefetch buffer
+ mcr p15, 0, r0, c7, c5, 6 @ Invalidate branch predictor array
+ mcr p15, 0, r0, c8, c5, 0 @ Invalidate instruction TLB
+ mcr p15, 0, r0, c8, c6, 0 @ Invalidate data TLB
+
+ /*
+ * Restore control register. This enables the MMU.
+ * The caches and prediction are not enabled here, they
+ * will be enabled after restoring the MMU table entry.
+ */
+ ldmia r3!, {r4}
+ stmia r3!, {r5} /* save original page table address */
+ stmia r3!, {r6} /* save original page table data */
+ stmia r3!, {r7} /* save modified page table data */
+
+ ldr r2, cache_pred_disable_mask
+ and r4, r2
+ mcr p15, 0, r4, c1, c0, 0
+ dsb
+ isb
+
+ ldr r0, =restoremmu_on
+ bx r0
+
+/*
+ * ==============================
+ * == Exit point from OFF mode ==
+ * ==============================
+ */
+restoremmu_on:
+
+ ldmfd sp!, {r0-r12, pc} @ restore regs and return
projects / platform / kernel / linux-rpi.git / commitdiff