/* * linux/arch/arm/mach-omap3/sram.S * * Omap3 specific functions that need to be run in internal SRAM * * Copyright (C) 2004, 2007, 2008 Texas Instruments, Inc. * Copyright (C) 2008 Nokia Corporation * * Rajendra Nayak * Richard Woodruff * Paul Walmsley * * 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 "cm2xxx_3xxx.h" /* * This file needs be built unconditionally as ARM to interoperate correctly * with non-Thumb-2-capable firmware. */ .arm .text /* r1 parameters */ #define SDRC_NO_UNLOCK_DLL 0x0 #define SDRC_UNLOCK_DLL 0x1 /* SDRC_DLLA_CTRL bit settings */ #define FIXEDDELAY_SHIFT 24 #define FIXEDDELAY_MASK (0xff << FIXEDDELAY_SHIFT) #define DLLIDLE_MASK 0x4 /* * SDRC_DLLA_CTRL default values: TI hardware team indicates that * FIXEDDELAY should be initialized to 0xf. This apparently was * empirically determined during process testing, so no derivation * was provided. */ #define FIXEDDELAY_DEFAULT (0x0f << FIXEDDELAY_SHIFT) /* SDRC_DLLA_STATUS bit settings */ #define LOCKSTATUS_MASK 0x4 /* SDRC_POWER bit settings */ #define SRFRONIDLEREQ_MASK 0x40 /* CM_IDLEST1_CORE bit settings */ #define ST_SDRC_MASK 0x2 /* CM_ICLKEN1_CORE bit settings */ #define EN_SDRC_MASK 0x2 /* CM_CLKSEL1_PLL bit settings */ #define CORE_DPLL_CLKOUT_DIV_SHIFT 0x1b /* * omap3_sram_configure_core_dpll - change DPLL3 M2 divider * * Params passed in registers: * r0 = new M2 divider setting (only 1 and 2 supported right now) * r1 = unlock SDRC DLL? (1 = yes, 0 = no). Only unlock DLL for * SDRC rates < 83MHz * r2 = number of MPU cycles to wait for SDRC to stabilize after * reprogramming the SDRC when switching to a slower MPU speed * r3 = increasing SDRC rate? (1 = yes, 0 = no) * * Params passed via the stack. The needed params will be copied in SRAM * before use by the code in SRAM (SDRAM is not accessible during SDRC * reconfiguration): * new SDRC_RFR_CTRL_0 register contents * new SDRC_ACTIM_CTRL_A_0 register contents * new SDRC_ACTIM_CTRL_B_0 register contents * new SDRC_MR_0 register value * new SDRC_RFR_CTRL_1 register contents * new SDRC_ACTIM_CTRL_A_1 register contents * new SDRC_ACTIM_CTRL_B_1 register contents * new SDRC_MR_1 register value * * If the param SDRC_RFR_CTRL_1 is 0, the parameters are not programmed into * the SDRC CS1 registers * * NOTE: This code no longer attempts to program the SDRC AC timing and MR * registers. This is because the code currently cannot ensure that all * L3 initiators (e.g., sDMA, IVA, DSS DISPC, etc.) are not accessing the * SDRAM when the registers are written. If the registers are changed while * an initiator is accessing SDRAM, memory can be corrupted and/or the SDRC * may enter an unpredictable state. In the future, the intent is to * re-enable this code in cases where we can ensure that no initiators are * touching the SDRAM. Until that time, users who know that their use case * can satisfy the above requirement can enable the CONFIG_OMAP3_SDRC_AC_TIMING * option. * * Richard Woodruff notes that any changes to this code must be carefully * audited and tested to ensure that they don't cause a TLB miss while * the SDRAM is inaccessible. Such a situation will crash the system * since it will cause the ARM MMU to attempt to walk the page tables. * These crashes may be intermittent. */ ENTRY(omap3_sram_configure_core_dpll) stmfd sp!, {r1-r12, lr} @ store regs to stack @ pull the extra args off the stack @ and store them in SRAM /* * PC-relative stores are deprecated in ARMv7 and lead to undefined behaviour * in Thumb-2: use a r7 as a base instead. * Be careful not to clobber r7 when maintaing this file. */ THUMB( adr r7, omap3_sram_configure_core_dpll ) .macro strtext Rt:req, label:req ARM( str \Rt, \label ) THUMB( str \Rt, [r7, \label - omap3_sram_configure_core_dpll] ) .endm ldr r4, [sp, #52] strtext r4, omap_sdrc_rfr_ctrl_0_val ldr r4, [sp, #56] strtext r4, omap_sdrc_actim_ctrl_a_0_val ldr r4, [sp, #60] strtext r4, omap_sdrc_actim_ctrl_b_0_val ldr r4, [sp, #64] strtext r4, omap_sdrc_mr_0_val ldr r4, [sp, #68] strtext r4, omap_sdrc_rfr_ctrl_1_val cmp r4, #0 @ if SDRC_RFR_CTRL_1 is 0, beq skip_cs1_params @ do not use cs1 params ldr r4, [sp, #72] strtext r4, omap_sdrc_actim_ctrl_a_1_val ldr r4, [sp, #76] strtext r4, omap_sdrc_actim_ctrl_b_1_val ldr r4, [sp, #80] strtext r4, omap_sdrc_mr_1_val skip_cs1_params: mrc p15, 0, r8, c1, c0, 0 @ read ctrl register bic r10, r8, #0x800 @ clear Z-bit, disable branch prediction mcr p15, 0, r10, c1, c0, 0 @ write ctrl register dsb @ flush buffered writes to interconnect isb @ prevent speculative exec past here cmp r3, #1 @ if increasing SDRC clk rate, bleq configure_sdrc @ program the SDRC regs early (for RFR) cmp r1, #SDRC_UNLOCK_DLL @ set the intended DLL state bleq unlock_dll blne lock_dll bl sdram_in_selfrefresh @ put SDRAM in self refresh, idle SDRC bl configure_core_dpll @ change the DPLL3 M2 divider mov r12, r2 bl wait_clk_stable @ wait for SDRC to stabilize bl enable_sdrc @ take SDRC out of idle cmp r1, #SDRC_UNLOCK_DLL @ wait for DLL status to change bleq wait_dll_unlock blne wait_dll_lock cmp r3, #1 @ if increasing SDRC clk rate, beq return_to_sdram @ return to SDRAM code, otherwise, bl configure_sdrc @ reprogram SDRC regs now return_to_sdram: mcr p15, 0, r8, c1, c0, 0 @ restore ctrl register 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] bic r12, r12, #FIXEDDELAY_MASK orr r12, r12, #FIXEDDELAY_DEFAULT orr r12, r12, #DLLIDLE_MASK str r12, [r11] @ (no OCP barrier needed) bx lr lock_dll: ldr r11, omap3_sdrc_dlla_ctrl ldr r12, [r11] bic r12, r12, #DLLIDLE_MASK 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, #SRFRONIDLEREQ_MASK @ enable self refresh on idle str r12, [r11] @ write back to SDRC_POWER register ldr r12, [r11] @ posted-write barrier for SDRC idle_sdrc: ldr r11, omap3_cm_iclken1_core @ read the CM_ICLKEN1_CORE reg ldr r12, [r11] bic r12, r12, #EN_SDRC_MASK @ disable iclk bit for SDRC str r12, [r11] wait_sdrc_idle: ldr r11, omap3_cm_idlest1_core ldr r12, [r11] and r12, r12, #ST_SDRC_MASK @ check for SDRC idle cmp r12, #ST_SDRC_MASK 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, r0, lsl #CORE_DPLL_CLKOUT_DIV_SHIFT str r12, [r11] ldr r12, [r11] @ posted-write barrier for CM bx lr wait_clk_stable: subs r12, r12, #1 bne wait_clk_stable bx lr enable_sdrc: ldr r11, omap3_cm_iclken1_core ldr r12, [r11] orr r12, r12, #EN_SDRC_MASK @ enable iclk bit for SDRC str r12, [r11] wait_sdrc_idle1: ldr r11, omap3_cm_idlest1_core ldr r12, [r11] and r12, r12, #ST_SDRC_MASK 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, #LOCKSTATUS_MASK cmp r12, #LOCKSTATUS_MASK bne wait_dll_lock bx lr wait_dll_unlock: ldr r11, omap3_sdrc_dlla_status ldr r12, [r11] and r12, r12, #LOCKSTATUS_MASK cmp r12, #0x0 bne wait_dll_unlock bx lr configure_sdrc: ldr r12, omap_sdrc_rfr_ctrl_0_val @ fetch value from SRAM ldr r11, omap3_sdrc_rfr_ctrl_0 @ fetch addr from SRAM str r12, [r11] @ store #ifdef CONFIG_OMAP3_SDRC_AC_TIMING ldr r12, omap_sdrc_actim_ctrl_a_0_val ldr r11, omap3_sdrc_actim_ctrl_a_0 str r12, [r11] ldr r12, omap_sdrc_actim_ctrl_b_0_val ldr r11, omap3_sdrc_actim_ctrl_b_0 str r12, [r11] ldr r12, omap_sdrc_mr_0_val ldr r11, omap3_sdrc_mr_0 str r12, [r11] #endif ldr r12, omap_sdrc_rfr_ctrl_1_val cmp r12, #0 @ if SDRC_RFR_CTRL_1 is 0, beq skip_cs1_prog @ do not program cs1 params ldr r11, omap3_sdrc_rfr_ctrl_1 str r12, [r11] #ifdef CONFIG_OMAP3_SDRC_AC_TIMING ldr r12, omap_sdrc_actim_ctrl_a_1_val ldr r11, omap3_sdrc_actim_ctrl_a_1 str r12, [r11] ldr r12, omap_sdrc_actim_ctrl_b_1_val ldr r11, omap3_sdrc_actim_ctrl_b_1 str r12, [r11] ldr r12, omap_sdrc_mr_1_val ldr r11, omap3_sdrc_mr_1 str r12, [r11] #endif skip_cs1_prog: ldr r12, [r11] @ posted-write barrier for SDRC bx lr .align 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_0: .word OMAP34XX_SDRC_REGADDR(SDRC_RFR_CTRL_0) omap3_sdrc_rfr_ctrl_1: .word OMAP34XX_SDRC_REGADDR(SDRC_RFR_CTRL_1) omap3_sdrc_actim_ctrl_a_0: .word OMAP34XX_SDRC_REGADDR(SDRC_ACTIM_CTRL_A_0) omap3_sdrc_actim_ctrl_a_1: .word OMAP34XX_SDRC_REGADDR(SDRC_ACTIM_CTRL_A_1) omap3_sdrc_actim_ctrl_b_0: .word OMAP34XX_SDRC_REGADDR(SDRC_ACTIM_CTRL_B_0) omap3_sdrc_actim_ctrl_b_1: .word OMAP34XX_SDRC_REGADDR(SDRC_ACTIM_CTRL_B_1) omap3_sdrc_mr_0: .word OMAP34XX_SDRC_REGADDR(SDRC_MR_0) omap3_sdrc_mr_1: .word OMAP34XX_SDRC_REGADDR(SDRC_MR_1) omap_sdrc_rfr_ctrl_0_val: .word 0xDEADBEEF omap_sdrc_rfr_ctrl_1_val: .word 0xDEADBEEF omap_sdrc_actim_ctrl_a_0_val: .word 0xDEADBEEF omap_sdrc_actim_ctrl_a_1_val: .word 0xDEADBEEF omap_sdrc_actim_ctrl_b_0_val: .word 0xDEADBEEF omap_sdrc_actim_ctrl_b_1_val: .word 0xDEADBEEF omap_sdrc_mr_0_val: .word 0xDEADBEEF omap_sdrc_mr_1_val: .word 0xDEADBEEF 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 ENDPROC(omap3_sram_configure_core_dpll) ENTRY(omap3_sram_configure_core_dpll_sz) .word . - omap3_sram_configure_core_dpll