1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * linux/arch/arm/plat-omap/sram-fn.S 4 * 5 * Functions that need to be run in internal SRAM 6 */ 7 8 #include <linux/linkage.h> 9 10 #include <asm/assembler.h> 11 12 #include <mach/hardware.h> 13 14 #include "iomap.h" 15 16 .text 17 18 /* 19 * Reprograms ULPD and CKCTL. 20 */ 21 .align 3 22 ENTRY(omap1_sram_reprogram_clock) 23 stmfd sp!, {r0 - r12, lr} @ save registers on stack 24 25 mov r2, #OMAP1_IO_ADDRESS(DPLL_CTL) & 0xff000000 26 orr r2, r2, #OMAP1_IO_ADDRESS(DPLL_CTL) & 0x00ff0000 27 orr r2, r2, #OMAP1_IO_ADDRESS(DPLL_CTL) & 0x0000ff00 28 29 mov r3, #OMAP1_IO_ADDRESS(ARM_CKCTL) & 0xff000000 30 orr r3, r3, #OMAP1_IO_ADDRESS(ARM_CKCTL) & 0x00ff0000 31 orr r3, r3, #OMAP1_IO_ADDRESS(ARM_CKCTL) & 0x0000ff00 32 33 tst r0, #1 << 4 @ want lock mode? 34 beq newck @ nope 35 bic r0, r0, #1 << 4 @ else clear lock bit 36 strh r0, [r2] @ set dpll into bypass mode 37 orr r0, r0, #1 << 4 @ set lock bit again 38 39 newck: 40 strh r1, [r3] @ write new ckctl value 41 strh r0, [r2] @ write new dpll value 42 43 mov r4, #0x0700 @ let the clocks settle 44 orr r4, r4, #0x00ff 45 delay: sub r4, r4, #1 46 cmp r4, #0 47 bne delay 48 49 lock: ldrh r4, [r2], #0 @ read back dpll value 50 tst r0, #1 << 4 @ want lock mode? 51 beq out @ nope 52 tst r4, #1 << 0 @ dpll rate locked? 53 beq lock @ try again 54 55 out: 56 ldmfd sp!, {r0 - r12, pc} @ restore regs and return 57 ENTRY(omap1_sram_reprogram_clock_sz) 58 .word . - omap1_sram_reprogram_clock 59