/* * linux/arch/arm/mach-omap3/sram.S * * Omap3 specific functions that need to be run in internal SRAM * * (C) Copyright 2007 * Texas Instruments Inc. * Rajendra Nayak * * (C) Copyright 2004 * Texas Instruments, * Richard Woodruff * * 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 #include #include #include #include "sdrc.h" #include "cm.h" .text /* * Change frequency of core dpll * r0 = sdrc_rfr_ctrl r1 = sdrc_actim_ctrla r2 = sdrc_actim_ctrlb r3 = M2 * r4 = Unlock SDRC DLL? (1 = yes, 0 = no) -- only unlock DLL for * SDRC rates < 83MHz */ ENTRY(omap3_sram_configure_core_dpll) stmfd sp!, {r1-r12, lr} @ store regs to stack ldr r4, [sp, #52] @ pull extra args off the stack dsb @ flush buffered writes to interconnect cmp r3, #0x2 blne configure_sdrc cmp r4, #0x1 bleq unlock_dll blne lock_dll bl sdram_in_selfrefresh @ put the SDRAM in self refresh bl configure_core_dpll bl enable_sdrc cmp r4, #0x1 bleq wait_dll_unlock blne wait_dll_lock cmp r3, #0x1 blne configure_sdrc isb @ prevent speculative exec past here mov r0, #0 @ return value ldmfd sp!, {r1-r12, pc} @ restore regs and return unlock_dll: ldr r11, omap3_sdrc_dlla_ctrl ldr r12, [r11] orr r12, r12, #0x4 str r12, [r11] @ (no OCP barrier needed) bx lr lock_dll: ldr r11, omap3_sdrc_dlla_ctrl ldr r12, [r11] bic r12, r12, #0x4 str r12, [r11] @ (no OCP barrier needed) bx lr sdram_in_selfrefresh: ldr r11, omap3_sdrc_power @ read the SDRC_POWER register ldr r12, [r11] @ read the contents of SDRC_POWER mov r9, r12 @ keep a copy of SDRC_POWER bits orr r12, r12, #0x40 @ enable self refresh on idle req bic r12, r12, #0x4 @ clear PWDENA str r12, [r11] @ write back to SDRC_POWER register ldr r12, [r11] @ posted-write barrier for SDRC ldr r11, omap3_cm_iclken1_core @ read the CM_ICLKEN1_CORE reg ldr r12, [r11] bic r12, r12, #0x2 @ disable iclk bit for SDRC str r12, [r11] wait_sdrc_idle: ldr r11, omap3_cm_idlest1_core ldr r12, [r11] and r12, r12, #0x2 @ check for SDRC idle cmp r12, #2 bne wait_sdrc_idle bx lr configure_core_dpll: ldr r11, omap3_cm_clksel1_pll ldr r12, [r11] ldr r10, core_m2_mask_val @ modify m2 for core dpll and r12, r12, r10 orr r12, r12, r3, lsl #0x1B @ r3 contains the M2 val str r12, [r11] ldr r12, [r11] @ posted-write barrier for CM mov r12, #0x800 @ wait for the clock to stabilise cmp r3, #2 bne wait_clk_stable bx lr wait_clk_stable: subs r12, r12, #1 bne wait_clk_stable nop nop nop nop nop nop nop nop nop nop bx lr enable_sdrc: ldr r11, omap3_cm_iclken1_core ldr r12, [r11] orr r12, r12, #0x2 @ enable iclk bit for SDRC str r12, [r11] wait_sdrc_idle1: ldr r11, omap3_cm_idlest1_core ldr r12, [r11] and r12, r12, #0x2 cmp r12, #0 bne wait_sdrc_idle1 restore_sdrc_power_val: ldr r11, omap3_sdrc_power str r9, [r11] @ restore SDRC_POWER, no barrier needed bx lr wait_dll_lock: ldr r11, omap3_sdrc_dlla_status ldr r12, [r11] and r12, r12, #0x4 cmp r12, #0x4 bne wait_dll_lock bx lr wait_dll_unlock: ldr r11, omap3_sdrc_dlla_status ldr r12, [r11] and r12, r12, #0x4 cmp r12, #0x0 bne wait_dll_unlock bx lr configure_sdrc: ldr r11, omap3_sdrc_rfr_ctrl str r0, [r11] ldr r11, omap3_sdrc_actim_ctrla str r1, [r11] ldr r11, omap3_sdrc_actim_ctrlb str r2, [r11] ldr r2, [r11] @ posted-write barrier for SDRC bx lr omap3_sdrc_power: .word OMAP34XX_SDRC_REGADDR(SDRC_POWER) omap3_cm_clksel1_pll: .word OMAP34XX_CM_REGADDR(PLL_MOD, CM_CLKSEL1) omap3_cm_idlest1_core: .word OMAP34XX_CM_REGADDR(CORE_MOD, CM_IDLEST) omap3_cm_iclken1_core: .word OMAP34XX_CM_REGADDR(CORE_MOD, CM_ICLKEN1) omap3_sdrc_rfr_ctrl: .word OMAP34XX_SDRC_REGADDR(SDRC_RFR_CTRL_0) omap3_sdrc_actim_ctrla: .word OMAP34XX_SDRC_REGADDR(SDRC_ACTIM_CTRL_A_0) omap3_sdrc_actim_ctrlb: .word OMAP34XX_SDRC_REGADDR(SDRC_ACTIM_CTRL_B_0) omap3_sdrc_dlla_status: .word OMAP34XX_SDRC_REGADDR(SDRC_DLLA_STATUS) omap3_sdrc_dlla_ctrl: .word OMAP34XX_SDRC_REGADDR(SDRC_DLLA_CTRL) core_m2_mask_val: .word 0x07FFFFFF ENTRY(omap3_sram_configure_core_dpll_sz) .word . - omap3_sram_configure_core_dpll