diff options
Diffstat (limited to 'arch/arm/mach-imx/lpddr2_freq_imx6sll.S')
| -rw-r--r-- | arch/arm/mach-imx/lpddr2_freq_imx6sll.S | 460 |
1 files changed, 460 insertions, 0 deletions
diff --git a/arch/arm/mach-imx/lpddr2_freq_imx6sll.S b/arch/arm/mach-imx/lpddr2_freq_imx6sll.S new file mode 100644 index 000000000000..c67d9e2b82ef --- /dev/null +++ b/arch/arm/mach-imx/lpddr2_freq_imx6sll.S @@ -0,0 +1,460 @@ +/* + * Copyright (C) 2016 Freescale Semiconductor, Inc. All Rights Reserved. + * + * 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. + */ + +#include <linux/linkage.h> +#include "hardware.h" + +#define CCM_CBCDR 0x14 +#define CCM_CBCMR 0x18 +#define CCM_CSCMR1 0x1c +#define CCM_CDHIPR 0x48 + +#define L2_CACHE_SYNC 0x730 +#define PL310_AUX_CTRL 0x104 +#define PL310_DCACHE_LOCKDOWN_BASE 0x900 +#define PL310_AUX_16WAY_BIT 0x10000 +#define PL310_LOCKDOWN_NBREGS 8 +#define PL310_LOCKDOWN_SZREG 4 +#define PL310_8WAYS_MASK 0x00FF +#define PL310_16WAYS_UPPERMASK 0xFF00 + +#define MMDC0_MDPDC 0x4 +#define MMDC0_MAPSR 0x404 +#define MMDC0_MADPCR0 0x410 + +#define HIGH_BUS_MODE 0x0 + + .macro wait_for_ccm_handshake + +1: + ldr r8, [r2, #CCM_CDHIPR] + cmp r8, #0 + bne 1b + + .endm + + .macro switch_to_24MHz + + /* periph2_clk2 sel to OSC_CLK */ + ldr r8, [r2, #CCM_CBCMR] + orr r8, r8, #(1 << 20) + str r8, [r2, #CCM_CBCMR] + + /* periph2_clk2_podf to 0 */ + ldr r8, [r2, #CCM_CBCDR] + bic r8, r8, #0x7 + str r8, [r2, #CCM_CBCDR] + + /* periph2_clk sel to periph2_clk2 */ + ldr r8, [r2, #CCM_CBCDR] + orr r8, r8, #(0x1 << 26) + str r8, [r2, #CCM_CBCDR] + + wait_for_ccm_handshake + + /* fabric_mmdc_podf to 0 */ + ldr r8, [r2, #CCM_CBCDR] + bic r8, r8, #(0x7 << 3) + str r8, [r2, #CCM_CBCDR] + + wait_for_ccm_handshake + + .endm + + .macro switch_to_100MHz + + /* check whether periph2_clk is from top path */ + ldr r8, [r2, #CCM_CBCDR] + ands r8, #(1 << 26) + beq skip_periph2_clk2_switch_100m + + /* now switch periph2_clk back. */ + ldr r8, [r2, #CCM_CBCDR] + bic r8, r8, #(1 << 26) + str r8, [r2, #CCM_CBCDR] + + wait_for_ccm_handshake + + /* + * on i.MX6SLL, pre_periph2_clk will be always from + * pll2_pfd2, so no need to set pre_periph2_clk + * parent, just set the mmdc divider directly. + */ +skip_periph2_clk2_switch_100m: + + /* fabric_mmdc_podf to 3 so that mmdc is 400 / 4 = 100MHz */ + ldr r8, [r2, #CCM_CBCDR] + bic r8, r8, #(0x7 << 3) + orr r8, r8, #(0x3 << 3) + str r8, [r2, #CCM_CBCDR] + + wait_for_ccm_handshake + + .endm + + .macro switch_to_400MHz + + /* check whether periph2_clk is from top path */ + ldr r8, [r2, #CCM_CBCDR] + ands r8, #(1 << 26) + beq skip_periph2_clk2_switch_400m + + /* now switch periph2_clk back. */ + ldr r8, [r2, #CCM_CBCDR] + bic r8, r8, #(1 << 26) + str r8, [r2, #CCM_CBCDR] + + wait_for_ccm_handshake + + /* + * on i.MX6SLL, pre_periph2_clk will be always from + * pll2_pfd2, so no need to set pre_periph2_clk + * parent, just set the mmdc divider directly. + */ +skip_periph2_clk2_switch_400m: + + /* fabric_mmdc_podf to 0 */ + ldr r8, [r2, #CCM_CBCDR] + bic r8, r8, #(0x7 << 3) + str r8, [r2, #CCM_CBCDR] + + wait_for_ccm_handshake + + .endm + + .macro mmdc_clk_lower_100MHz + /* if MMDC is not in 400MHz mode, skip double mu count */ + cmp r1, #HIGH_BUS_MODE + bne 1f + + /* + * Prior to reducing the DDR frequency (at 528/400 MHz), + * read the Measure unit count bits (MU_UNIT_DEL_NUM) + */ + ldr r8, =0x8B8 + ldr r6, [r5, r8] + /* Original MU unit count */ + mov r6, r6, LSR #16 + ldr r4, =0x3FF + and r6, r6, r4 + /* Original MU unit count * 2 */ + mov r7, r6, LSL #1 + /* + * Bypass the automatic measure unit when below 100 MHz + * by setting the Measure unit bypass enable bit (MU_BYP_EN) + */ + ldr r6, [r5, r8] + orr r6, r6, #0x400 + str r6, [r5, r8] + /* + * Double the measure count value read in step 1 and program it in the + * measurement bypass bits (MU_BYP_VAL) of the MMDC PHY Measure Unit + * Register for the reduced frequency operation below 100 MHz + */ + ldr r6, [r5, r8] + ldr r4, =0x3FF + bic r6, r6, r4 + orr r6, r6, r7 + str r6, [r5, r8] + + /* For freq lower than 100MHz, need to set RALAT to 2 */ + ldr r6, [r5, #0x18] + bic r6, r6, #(0x7 << 6) + orr r6, r6, #(0x2 << 6) + str r6, [r5, #0x18] +1: + .endm + + .macro mmdc_clk_above_100MHz + + /* Make sure that the PHY measurement unit is NOT in bypass mode */ + ldr r8, =0x8B8 + ldr r6, [r5, r8] + bic r6, r6, #0x400 + str r6, [r5, r8] + /* Now perform a Force Measurement. */ + ldr r6, [r5, r8] + orr r6, r6, #0x800 + str r6, [r5, r8] + /* Wait for FRC_MSR to clear. */ +force_measure1: + ldr r6, [r5, r8] + and r6, r6, #0x800 + cmp r6, #0x0 + bne force_measure1 + + /* For freq higher than 100MHz, need to set RALAT to 5 */ + ldr r6, [r5, #0x18] + bic r6, r6, #(0x7 << 6) + orr r6, r6, #(0x5 << 6) + str r6, [r5, #0x18] + + .endm + + .align 3 +/* + * Below code can be used by i.MX6SLL when changing the + * frequency of MMDC. the MMDC is the same on these two SOCs. + */ +ENTRY(imx6sll_lpddr2_freq_change) + push {r2 - r8} + + /* + * To ensure no page table walks occur in DDR, we + * have a another page table stored in IRAM that only + * contains entries pointing to IRAM, AIPS1 and AIPS2. + * We need to set the TTBR1 to the new IRAM TLB. + * Do the following steps: + * 1. Flush the Branch Target Address Cache (BTAC) + * 2. Set TTBR1 to point to IRAM page table. + * 3. Disable page table walks in TTBR0 (PD0 = 1) + * 4. Set TTBR0.N=1, implying 0-2G is translated by TTBR0 + * and 2-4G is translated by TTBR1. + */ + + ldr r6, =iram_tlb_phys_addr + ldr r7, [r6] + + /* Flush the Branch Target Address Cache (BTAC) */ + ldr r6, =0x0 + mcr p15, 0, r6, c7, c1, 6 + + /* Disable Branch Prediction, Z bit in SCTLR. */ + mrc p15, 0, r6, c1, c0, 0 + bic r6, r6, #0x800 + mcr p15, 0, r6, c1, c0, 0 + + dsb + isb + /* Store the IRAM table in TTBR1 */ + mcr p15, 0, r7, c2, c0, 1 + + /* Read TTBCR and set PD0=1, N = 1 */ + mrc p15, 0, r6, c2, c0, 2 + orr r6, r6, #0x11 + mcr p15, 0, r6, c2, c0, 2 + + dsb + isb + + /* flush the TLB */ + ldr r6, =0x0 + mcr p15, 0, r6, c8, c3, 0 + + /* Disable L1 data cache. */ + mrc p15, 0, r6, c1, c0, 0 + bic r6, r6, #0x4 + mcr p15, 0, r6, c1, c0, 0 + + dsb + isb + +#ifdef CONFIG_CACHE_L2X0 + /* + * Need to make sure the buffers in L2 are drained. + * Performing a sync operation does this. + */ + ldr r7, =IMX_IO_P2V(MX6Q_L2_BASE_ADDR) + mov r6, #0x0 + str r6, [r7, #L2_CACHE_SYNC] + + /* + * The second dsb might be needed to keep cache sync (device write) + * ordering with the memory accesses before it. + */ + dsb + isb + + ldr r3, [r7, #PL310_AUX_CTRL] + tst r3, #PL310_AUX_16WAY_BIT + mov r3, #PL310_8WAYS_MASK + orrne r3, #PL310_16WAYS_UPPERMASK + mov r6, #PL310_LOCKDOWN_NBREGS + add r5, r7, #PL310_DCACHE_LOCKDOWN_BASE +1: /* lock Dcache and Icache */ + str r3, [r5], #PL310_LOCKDOWN_SZREG + str r3, [r5], #PL310_LOCKDOWN_SZREG + subs r6, r6, #1 + bne 1b +#endif + + ldr r2, =IMX_IO_P2V(MX6Q_CCM_BASE_ADDR) + ldr r3, =IMX_IO_P2V(MX6Q_ANATOP_BASE_ADDR) + ldr r5, =IMX_IO_P2V(MX6Q_MMDC_P0_BASE_ADDR) + + /* Disable Automatic power savings. */ + ldr r6, [r5, #MMDC0_MAPSR] + orr r6, r6, #0x1 + str r6, [r5, #MMDC0_MAPSR] + + /* Delay for a while */ + ldr r8, =10 +delay: + ldr r7, =0 +cont: + ldr r6, [r5, r7] + add r7, r7, #4 + cmp r7, #16 + bne cont + sub r8, r8, #1 + cmp r8, #0 + bgt delay + + /* Make the DDR explicitly enter self-refresh. */ + ldr r6, [r5, #MMDC0_MAPSR] + orr r6, r6, #0x200000 + str r6, [r5, #MMDC0_MAPSR] + +poll_dvfs_set_1: + ldr r6, [r5, #MMDC0_MAPSR] + and r6, r6, #0x2000000 + cmp r6, #0x2000000 + bne poll_dvfs_set_1 + + /* set SBS step-by-step mode */ + ldr r6, [r5, #MMDC0_MADPCR0] + orr r6, r6, #0x100 + str r6, [r5, #MMDC0_MADPCR0] + + ldr r6, =100000000 + cmp r0, r6 + bgt set_ddr_mu_above_100 + mmdc_clk_lower_100MHz + +set_ddr_mu_above_100: + ldr r6, =24000000 + cmp r0, r6 + beq set_to_24MHz + + ldr r6, =100000000 + cmp r0, r6 + beq set_to_100MHz + + switch_to_400MHz + + mmdc_clk_above_100MHz + + b done + +set_to_24MHz: + switch_to_24MHz + b done +set_to_100MHz: + switch_to_100MHz +done: + /* clear DVFS - exit from self refresh mode */ + ldr r6, [r5, #MMDC0_MAPSR] + bic r6, r6, #0x200000 + str r6, [r5, #MMDC0_MAPSR] + +poll_dvfs_clear_1: + ldr r6, [r5, #MMDC0_MAPSR] + and r6, r6, #0x2000000 + cmp r6, #0x2000000 + beq poll_dvfs_clear_1 + + /* Enable Automatic power savings. */ + ldr r6, [r5, #MMDC0_MAPSR] + bic r6, r6, #0x1 + str r6, [r5, #MMDC0_MAPSR] + + /* clear SBS - unblock DDR accesses */ + ldr r6, [r5, #MMDC0_MADPCR0] + bic r6, r6, #0x100 + str r6, [r5, #MMDC0_MADPCR0] + + ldr r6, =0xa0000000 + str r6, [r5, #0x83c] + + +#ifdef CONFIG_CACHE_L2X0 + ldr r7, =IMX_IO_P2V(MX6Q_L2_BASE_ADDR) + ldr r3, [r7, #PL310_AUX_CTRL] + tst r3, #PL310_AUX_16WAY_BIT + mov r6, #PL310_LOCKDOWN_NBREGS + mov r3, #0x00 /* 8 ways mask */ + orrne r3, #0x0000 /* 16 ways mask */ + add r5, r7, #PL310_DCACHE_LOCKDOWN_BASE +1: /* lock Dcache and Icache */ + str r3, [r5], #PL310_LOCKDOWN_SZREG + str r3, [r5], #PL310_LOCKDOWN_SZREG + subs r6, r6, #1 + bne 1b +#endif + + /* Enable L1 data cache. */ + mrc p15, 0, r6, c1, c0, 0 + orr r6, r6, #0x4 + mcr p15, 0, r6, c1, c0, 0 + + /* Restore the TTBCR */ + dsb + isb + + /* Read TTBCR and set PD0=0, N = 0 */ + mrc p15, 0, r6, c2, c0, 2 + bic r6, r6, #0x11 + mcr p15, 0, r6, c2, c0, 2 + dsb + isb + + /* flush the TLB */ + ldr r6, =0x0 + mcr p15, 0, r6, c8, c3, 0 + + dsb + isb + + /* Enable Branch Prediction, Z bit in SCTLR. */ + mrc p15, 0, r6, c1, c0, 0 + orr r6, r6, #0x800 + mcr p15, 0, r6, c1, c0, 0 + + /* Flush the Branch Target Address Cache (BTAC) */ + ldr r6, =0x0 + mcr p15, 0, r6, c7, c1, 6 + + nop + nop + nop + nop + nop + + nop + nop + nop + nop + nop + + nop + nop + nop + nop + nop + + nop + nop + nop + nop + nop + + nop + nop + nop + nop + nop + + /* Restore registers */ + pop {r2 - r8} + mov pc, lr |