diff options
Diffstat (limited to 'arch/arm/mach-mx6/mx6sl_ddr.S')
| -rw-r--r-- | arch/arm/mach-mx6/mx6sl_ddr.S | 570 |
1 files changed, 570 insertions, 0 deletions
diff --git a/arch/arm/mach-mx6/mx6sl_ddr.S b/arch/arm/mach-mx6/mx6sl_ddr.S new file mode 100644 index 00000000..bac1e7c2 --- /dev/null +++ b/arch/arm/mach-mx6/mx6sl_ddr.S @@ -0,0 +1,570 @@ +/* + * Copyright (C) 2012-2013 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. + + * 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., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include <linux/linkage.h> +#include <mach/hardware.h> +.extern iram_tlb_phys_addr +.extern mx6sl_ddr_freq_base +.extern mx6sl_ddr_freq_phys_addr + + .macro mx6sl_switch_to_24MHz + + /* Set MMDC clock to be sourced from PLL3. */ + /* Ensure first periph2_clk2 is sourced from PLL3. */ + /* Set the PERIPH2_CLK2_PODF to divide by 2. */ + ldr r6, [r2, #0x14] + bic r6, r6, #0x7 + orr r6, r6, #0x1 + str r6, [r2, #0x14] + + /* Select PLL3 to source MMDC. */ + ldr r6, [r2, #0x18] + bic r6, r6, #0x100000 + str r6, [r2, #0x18] + + /* Swtich periph2_clk_sel to run from PLL3. */ + ldr r6, [r2, #0x14] + orr r6, r6, #0x4000000 + str r6, [r2, #0x14] + +periph2_clk_switch1: + ldr r6, [r2, #0x48] + cmp r6, #0 + bne periph2_clk_switch1 + + /* Need to clock gate the 528 PFDs before + * powering down PLL2. + * Only the PLL2_PFD2_400M should be ON + * as it feeds the MMDC + */ + ldr r6, [r3, #0x100] + orr r6, r6, #0x800000 + str r6, [r3, #0x100] + + /* Set PLL2 to bypass state. We should be here + *only if MMDC is not sourced from PLL2.*/ + ldr r6, [r3, #0x30] + orr r6, r6, #0x10000 + str r6, [r3, #0x30] + + ldr r6, [r3, #0x30] + orr r6, r6, #0x1000 + str r6, [r3, #0x30] + + /* Ensure pre_periph2_clk_mux is set to pll2 */ + ldr r6, [r2, #0x18] + bic r6, r6, #0x600000 + str r6, [r2, #0x18] + + /* Set MMDC clock to be sourced from the bypassed PLL2. */ + ldr r6, [r2, #0x14] + bic r6, r6, #0x4000000 + str r6, [r2, #0x14] + +periph2_clk_switch2: + ldr r6, [r2, #0x48] + cmp r6, #0 + bne periph2_clk_switch2 + + /* Now move MMDC back to periph2_clk2 source. + * after selecting PLL2 as the option. + */ + /* Select PLL2 as the source. */ + ldr r6, [r2, #0x18] + orr r6, r6, #0x100000 + str r6, [r2, #0x18] + + /* set periph2_clk2_podf to divide by 1. */ + ldr r6, [r2, #0x14] + bic r6, r6, #0x7 + str r6, [r2, #0x14] + + /* Now move periph2_clk to periph2_clk2 source */ + ldr r6, [r2, #0x14] + orr r6, r6, #0x4000000 + str r6, [r2, #0x14] + +periph2_clk_switch3: + ldr r6, [r2, #0x48] + cmp r6, #0 + bne periph2_clk_switch3 + + /* Now set the MMDC PODF back to 1.*/ + ldr r6, [r2, #0x14] + bic r6, r6, #0x38 + str r6, [r2, #0x14] + +mmdc_podf0: + ldr r6, [r2, #0x48] + cmp r6, #0 + bne mmdc_podf0 + + .endm + + .macro ddr_switch_400MHz + + /* Set MMDC divider first, in case PLL3 is at 480MHz. */ + ldr r6, [r3, #0x10] + and r6, r6, #0x10000 + cmp r6, #0x10000 + beq pll3_in_bypass + /* Set MMDC divder to divide by 2. */ + ldr r6, [r2, #0x14] + bic r6, r6, #0x38 + orr r6, r6, #0x8 + str r6, [r2, #0x14] + +mmdc_podf: + ldr r6, [r2, #0x48] + cmp r6, #0 + bne mmdc_podf + +pll3_in_bypass: + + /* Check if we are switching between + * 400Mhz <-> 100MHz.If so, we should + * try to source MMDC from PLL2_200M. + */ + cmp r1, #0 + beq not_low_bus_freq + + /* Ensure that MMDC is sourced from PLL2 mux first. */ + ldr r6, [r2, #0x14] + bic r6, r6, #0x4000000 + str r6, [r2, #0x14] + +periph2_clk_switch4: + ldr r6, [r2, #0x48] + cmp r6, #0 + bne periph2_clk_switch4 + +not_low_bus_freq: + /* Now ensure periph2_clk2_sel mux is set to PLL3 */ + ldr r6, [r2, #0x18] + bic r6, r6, #0x100000 + str r6, [r2, #0x18] + + /* Now switch MMDC to PLL3. */ + ldr r6, [r2, #0x14] + orr r6, r6, #0x4000000 + str r6, [r2, #0x14] + +periph2_clk_switch5: + ldr r6, [r2, #0x48] + cmp r6, #0 + bne periph2_clk_switch5 + + /* Check if PLL2 is already unlocked. + * If so do nothing with PLL2. + */ + cmp r1, #0 + beq pll2_already_on + + /* Now power up PLL2 and unbypass it. */ + ldr r6, [r3, #0x30] + bic r6, r6, #0x1000 + str r6, [r3, #0x30] + + /* Make sure PLL2 has locked.*/ +wait_for_pll_lock: + ldr r6, [r3, #0x30] + and r6, r6, #0x80000000 + cmp r6, #0x80000000 + bne wait_for_pll_lock + + ldr r6, [r3, #0x30] + bic r6, r6, #0x10000 + str r6, [r3, #0x30] + + /* Need to enable the 528 PFDs after + * powering up PLL2. + * Only the PLL2_PFD2_400M should be ON + * as it feeds the MMDC. Rest should have + * been managed by clock code. + */ + ldr r6, [r3, #0x100] + bic r6, r6, #0x800000 + str r6, [r3, #0x100] + +pll2_already_on: + /* Now switch MMDC clk back to pll2_mux option. */ + /* Ensure pre_periph2_clk2 is set to pll2_pfd_400M */ + /* If switching to audio DDR freq, set the + * pre_periph2_clk2 to PLL2_PFD_200M + */ + ldr r6, =400000000 + cmp r6, r0 + bne use_pll2_pfd_200M + + ldr r6, [r2, #0x18] + bic r6, r6, #0x600000 + orr r6, r6, #0x200000 + str r6, [r2, #0x18] + ldr r6, =400000000 + b cont2 + +use_pll2_pfd_200M: + ldr r6, [r2, #0x18] + orr r6, r6, #0x600000 + str r6, [r2, #0x18] + ldr r6, =200000000 + +cont2: + ldr r4, [r2, #0x14] + bic r4, r4, #0x4000000 + str r4, [r2, #0x14] + +periph2_clk_switch6: + ldr r4, [r2, #0x48] + cmp r4, #0 + bne periph2_clk_switch6 + +change_divider_only: + /* Calculate the MMDC divider + * based on the requested freq. + */ + ldr r4, =0 +Loop2: + sub r6, r6, r0 + cmp r6, r0 + blt Div_Found + add r4, r4, #1 + bgt Loop2 + + /* Shift divider into correct offset. */ + lsl r4, r4, #3 +Div_Found: + /* Set the MMDC PODF. */ + ldr r6, [r2, #0x14] + bic r6, r6, #0x38 + orr r6, r6, r4 + str r6, [r2, #0x14] + +mmdc_podf1: + ldr r6, [r2, #0x48] + cmp r6, #0 + bne mmdc_podf1 + + .endm + + .macro mmdc_clk_lower_100MHz + + /* Prior to reducing the DDR frequency (at 528/400 MHz), + read the Measure unit count bits (MU_UNIT_DEL_NUM) */ + ldr r5, =0x8B8 + ldr r6, [r8, r5] + /* 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, [r8, r5] + orr r6, r6, #0x400 + str r6, [r8, r5] + /* 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, [r8, r5] + ldr r4, =0x3FF + bic r6, r6, r4 + orr r6, r6, r7 + str r6, [r8, r5] + /* Now perform a Force Measurement. */ + ldr r6, [r8, r5] + orr r6, r6, #0x800 + str r6, [r8, r5] + /* Wait for FRC_MSR to clear. */ +force_measure: + ldr r6, [r8, r5] + and r6, r6, #0x800 + cmp r6, #0x0 + bne force_measure + + .endm + + .macro mmdc_clk_above_100MHz + + /* Make sure that the PHY measurement unit is NOT in bypass mode */ + ldr r5, =0x8B8 + ldr r6, [r8, r5] + bic r6, r6, #0x400 + str r6, [r8, r5] + /* Now perform a Force Measurement. */ + ldr r6, [r8, r5] + orr r6, r6, #0x800 + str r6, [r8, r5] + /* Wait for FRC_MSR to clear. */ +force_measure1: + ldr r6, [r8, r5] + and r6, r6, #0x800 + cmp r6, #0x0 + bne force_measure1 + .endm + + .align 3 +/* + * mx6sl_ddr_iram + * + * Idle the processor (eg, wait for interrupt). + * Make sure DDR is in self-refresh. + * IRQs are already disabled. + * r0 : DDR freq. + * r1: low_bus_freq_mode flag + */ +ENTRY(mx6sl_ddr_iram) + + push {r4-r10} + + /* + * 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 + +mx6sl_ddr_freq_change: + /* 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 + + /* + * Sync L2 and then disable it. + */ + dsb + ldr r4, =L2_BASE_ADDR + add r4, r4, #PERIPBASE_VIRT + ldr r6, =0x0 + str r6, [r4, #0x730] + /* Disable L2. */ + str r6, [r4, #0x100] + + dsb + isb + + ldr r3, =ANATOP_BASE_ADDR + add r3, r3, #PERIPBASE_VIRT + ldr r2, =CCM_BASE_ADDR + add r2, r2, #PERIPBASE_VIRT + ldr r8, =MMDC_P0_BASE_ADDR + add r8, r8, #PERIPBASE_VIRT + + /* Disable Automatic power savings. */ + ldr r6, [r8, #0x404] + orr r6, r6, #0x01 + str r6, [r8, #0x404] + + /* Disable MMDC power down timer. */ + /*MMDC0_MDPDC disable power down timer */ + ldr r6, [r8, #0x4] + bic r6, r6, #0xff00 + str r6, [r8, #0x4] + + /* Delay for a while */ + ldr r10, =10 +delay1: + ldr r7, =0 +cont1: + ldr r6, [r8, r7] + add r7, r7, #4 + cmp r7, #16 + bne cont1 + sub r10, r10, #1 + cmp r10, #0 + bgt delay1 + + /* Make the DDR explicitly enter self-refresh. */ + ldr r6, [r8, #0x404] + orr r6, r6, #0x200000 + str r6, [r8, #0x404] + +poll_dvfs_set_1: + ldr r6, [r8, #0x404] + and r6, r6, #0x2000000 + cmp r6, #0x2000000 + bne poll_dvfs_set_1 + + /* set SBS step-by-step mode */ + ldr r6, [r8, #0x410] + orr r6, r6, #0x100 + str r6, [r8, #0x410] + + ldr r10, =100000000 + cmp r0, r10 + bgt set_ddr_mu_above_100 + mmdc_clk_lower_100MHz + +set_ddr_mu_above_100: + ldr r10, =24000000 + cmp r0, r10 + beq set_to_24MHz + + ddr_switch_400MHz + ldr r10, =100000000 + cmp r0, r10 + blt done + mmdc_clk_above_100MHz + b done + +set_to_24MHz: + mx6sl_switch_to_24MHz + +done: + /* clear DVFS - exit from self refresh mode */ + ldr r6, [r8, #0x404] + bic r6, r6, #0x200000 + str r6, [r8, #0x404] + +poll_dvfs_clear_1: + ldr r6, [r8, #0x404] + and r6, r6, #0x2000000 + cmp r6, #0x2000000 + beq poll_dvfs_clear_1 + + /* Enable Automatic power savings. */ + ldr r6, [r8, #0x404] + bic r6, r6, #0x01 + str r6, [r8, #0x404] + + ldr r10, =24000000 + cmp r0, r10 + beq skip_power_down + + /* Enable MMDC power down timer. */ + ldr r6, [r8, #0x4] + orr r6, r6, #0x5500 + str r6, [r8, #0x4] + +skip_power_down: + /* clear SBS - unblock DDR accesses */ + ldr r6, [r8, #0x410] + bic r6, r6, #0x100 + str r6, [r8, #0x410] + + /* Enable L2. */ + ldr r1, =L2_BASE_ADDR + add r1, r1, #PERIPBASE_VIRT + ldr r6, =0x1 + str r6, [r1, #0x100] + + /* 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 + + pop {r4-r10} + + /* Restore registers */ + mov pc, lr |