diff options
Diffstat (limited to 'kernel/arch/arm/mach-omap2/sram34xx.S')
| -rw-r--r-- | kernel/arch/arm/mach-omap2/sram34xx.S | 346 |
1 files changed, 346 insertions, 0 deletions
diff --git a/kernel/arch/arm/mach-omap2/sram34xx.S b/kernel/arch/arm/mach-omap2/sram34xx.S new file mode 100644 index 000000000..1446331b5 --- /dev/null +++ b/kernel/arch/arm/mach-omap2/sram34xx.S @@ -0,0 +1,346 @@ +/* + * 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 <rnayak@ti.com> + * Richard Woodruff <r-woodruff2@ti.com> + * 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 <linux/linkage.h> + +#include <asm/assembler.h> + +#include "soc.h" +#include "iomap.h" +#include "sdrc.h" +#include "cm3xxx.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. + */ + .align 3 +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 + |