diff options
Diffstat (limited to 'arch/arm/mach-omap1/sram.S')
| -rw-r--r-- | arch/arm/mach-omap1/sram.S | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/arch/arm/mach-omap1/sram.S b/arch/arm/mach-omap1/sram.S new file mode 100644 index 0000000000..89f4dc1b70 --- /dev/null +++ b/arch/arm/mach-omap1/sram.S @@ -0,0 +1,58 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * linux/arch/arm/plat-omap/sram-fn.S + * + * Functions that need to be run in internal SRAM + */ + +#include <linux/linkage.h> +#include <linux/soc/ti/omap1-io.h> + +#include <asm/assembler.h> + +#include "hardware.h" +#include "iomap.h" + + .text + +/* + * Reprograms ULPD and CKCTL. + */ + .align 3 +ENTRY(omap1_sram_reprogram_clock) + stmfd sp!, {r0 - r12, lr} @ save registers on stack + + mov r2, #OMAP1_IO_ADDRESS(DPLL_CTL) & 0xff000000 + orr r2, r2, #OMAP1_IO_ADDRESS(DPLL_CTL) & 0x00ff0000 + orr r2, r2, #OMAP1_IO_ADDRESS(DPLL_CTL) & 0x0000ff00 + + mov r3, #OMAP1_IO_ADDRESS(ARM_CKCTL) & 0xff000000 + orr r3, r3, #OMAP1_IO_ADDRESS(ARM_CKCTL) & 0x00ff0000 + orr r3, r3, #OMAP1_IO_ADDRESS(ARM_CKCTL) & 0x0000ff00 + + tst r0, #1 << 4 @ want lock mode? + beq newck @ nope + bic r0, r0, #1 << 4 @ else clear lock bit + strh r0, [r2] @ set dpll into bypass mode + orr r0, r0, #1 << 4 @ set lock bit again + +newck: + strh r1, [r3] @ write new ckctl value + strh r0, [r2] @ write new dpll value + + mov r4, #0x0700 @ let the clocks settle + orr r4, r4, #0x00ff +delay: sub r4, r4, #1 + cmp r4, #0 + bne delay + +lock: ldrh r4, [r2], #0 @ read back dpll value + tst r0, #1 << 4 @ want lock mode? + beq out @ nope + tst r4, #1 << 0 @ dpll rate locked? + beq lock @ try again + +out: + ldmfd sp!, {r0 - r12, pc} @ restore regs and return +ENTRY(omap1_sram_reprogram_clock_sz) + .word . - omap1_sram_reprogram_clock |