From: Alan Tull <at...@opensource.altera.com> Add code that requests that the sdr controller go into self-refresh mode. This code is run from ocram.
This patch assumes that u-boot has already configured sdr: sdr.ctrlcfg.lowpwreq.selfrfshmask = 3 sdr.ctrlcfg.lowpwrtiming.clkdisablecycles = 8 sdr.ctrlcfg.dramtiming4.selfrfshexit = 512 How to suspend to ram: $ echo enabled > \ /sys/devices/soc/ffc02000.serial0/tty/ttyS0/power/wakeup $ echo -n mem > /sys/power/state Signed-off-by: Alan Tull <at...@opensource.altera.com> --- arch/arm/mach-socfpga/Makefile | 1 + arch/arm/mach-socfpga/core.h | 4 + arch/arm/mach-socfpga/pm.c | 141 ++++++++++++++++++++++++++++++++ arch/arm/mach-socfpga/self-refresh.S | 148 ++++++++++++++++++++++++++++++++++ arch/arm/mach-socfpga/socfpga.c | 10 +++ 5 files changed, 304 insertions(+) create mode 100644 arch/arm/mach-socfpga/pm.c create mode 100644 arch/arm/mach-socfpga/self-refresh.S diff --git a/arch/arm/mach-socfpga/Makefile b/arch/arm/mach-socfpga/Makefile index 6dd7a93..0591927 100644 --- a/arch/arm/mach-socfpga/Makefile +++ b/arch/arm/mach-socfpga/Makefile @@ -4,3 +4,4 @@ obj-y := socfpga.o obj-$(CONFIG_SMP) += headsmp.o platsmp.o +obj-$(CONFIG_SUSPEND) += pm.o self-refresh.o diff --git a/arch/arm/mach-socfpga/core.h b/arch/arm/mach-socfpga/core.h index c4a0929..cc1a2fb 100644 --- a/arch/arm/mach-socfpga/core.h +++ b/arch/arm/mach-socfpga/core.h @@ -38,6 +38,7 @@ extern void socfpga_sysmgr_init(void); extern void __iomem *sys_manager_base_addr; extern void __iomem *rst_manager_base_addr; +extern void __iomem *sdr_ctl_base_addr; extern struct smp_operations socfpga_smp_ops; extern char secondary_trampoline, secondary_trampoline_end; @@ -46,4 +47,7 @@ extern unsigned long cpu1start_addr; #define SOCFPGA_SCU_VIRT_BASE 0xfffec000 +u32 socfpga_sdram_self_refresh(u32 sdr_base, u32 scu_base); +extern unsigned int socfpga_sdram_self_refresh_sz; + #endif diff --git a/arch/arm/mach-socfpga/pm.c b/arch/arm/mach-socfpga/pm.c new file mode 100644 index 0000000..02c3719 --- /dev/null +++ b/arch/arm/mach-socfpga/pm.c @@ -0,0 +1,141 @@ +/* + * arch/arm/mach-socfpga/pm.c + * + * Copyright (C) 2014 Altera Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/bitops.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/of_platform.h> +#include <linux/suspend.h> +#include <asm/suspend.h> +#include <asm/fncpy.h> +#include "core.h" + +/* Pointer to function copied to ocram */ +static u32 (*socfpga_sdram_self_refresh_in_ocram)(u32 sdr_base, u32 scu_base); + +/* Round up a pointer address to fix aligment for fncpy() */ +static void *fncpy_align(void *ptr) +{ + u32 value = (u32)ptr; + + if ((value & (FNCPY_ALIGN - 1)) != 0) + value = ((value & ~(FNCPY_ALIGN - 1)) + FNCPY_ALIGN); + + return (void *)value; +} + +static void *socfpga_init_ocram_exec(void) +{ + struct device_node *np; + const __be32 *prop; + u32 ocram_hwaddr, len; + void __iomem *iomem_exec_ocram; + size_t size; + + np = of_find_compatible_node(NULL, NULL, "mmio-sram"); + if (!np) { + pr_err("SOCFPGA: Unable to find mmio-sram in dtb\n"); + return 0; + } + + /* Determine the OCRAM address and size */ + prop = of_get_property(np, "reg", &size); + ocram_hwaddr = be32_to_cpup(prop++); + len = be32_to_cpup(prop); + + if (!prop || size < sizeof(*prop)) { + pr_err("SOCFPGA: Unable to find OCRAM mapping in dtb\n"); + return 0; + } + + iomem_exec_ocram = __arm_ioremap_exec(ocram_hwaddr, len, 0); + + /* Fix alignment to work with fncpy */ + iomem_exec_ocram = fncpy_align(iomem_exec_ocram); + + return iomem_exec_ocram; +} + +static int socfpga_setup_ocram_self_refresh(void) +{ + void *ocram_addr; + + /* Configure ocram and make it executable */ + ocram_addr = socfpga_init_ocram_exec(); + WARN(!ocram_addr, "Unable to initialize ocram for pm"); + if (!ocram_addr) + return -EFAULT; + + /* Copy the code that puts DDR in self refresh to ocram */ + socfpga_sdram_self_refresh_in_ocram = + (void *)fncpy((void *)ocram_addr, + &socfpga_sdram_self_refresh, + socfpga_sdram_self_refresh_sz); + + WARN(!socfpga_sdram_self_refresh_in_ocram, + "could not copy function to ocram"); + if (!socfpga_sdram_self_refresh_in_ocram) + return -EFAULT; + + return 0; +} + +static int socfpga_pm_suspend(unsigned long arg) +{ + u32 ret; + + ret = socfpga_sdram_self_refresh_in_ocram((u32)sdr_ctl_base_addr, + (u32)socfpga_scu_base_addr); + + pr_debug("%s self-refresh loops request=%d exit=%d\n", __func__, + ret & 0xffff, (ret >> 16) & 0xffff); + + return 0; +} + +static int socfpga_pm_enter(suspend_state_t state) +{ + switch (state) { + case PM_SUSPEND_STANDBY: + case PM_SUSPEND_MEM: + outer_disable(); + cpu_suspend(0, socfpga_pm_suspend); + outer_resume(); + break; + default: + return -EINVAL; + } + return 0; +} + +static const struct platform_suspend_ops socfpga_pm_ops = { + .valid = suspend_valid_only_mem, + .enter = socfpga_pm_enter, +}; + +static int __init socfpga_pm_init(void) +{ + if (socfpga_setup_ocram_self_refresh()) + return -EFAULT; + + suspend_set_ops(&socfpga_pm_ops); + pr_info("SoCFPGA initialized for DDR self-refresh during suspend.\n"); + + return 0; +} +arch_initcall(socfpga_pm_init); diff --git a/arch/arm/mach-socfpga/self-refresh.S b/arch/arm/mach-socfpga/self-refresh.S new file mode 100644 index 0000000..a58b58f --- /dev/null +++ b/arch/arm/mach-socfpga/self-refresh.S @@ -0,0 +1,148 @@ +/* + * Copyright (C) 2014 Altera Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>. + */ +#include <linux/linkage.h> +#include <asm/assembler.h> + +#define SOCFPGA_SCU_CTRL_OFFS 0 +#define SCU_STANDBY_ENA 0x20 +#define MAX_LOOP_COUNT 1000 + +/* Register offset */ +#define SDR_CTRLGRP_LOWPWREQ_ADDR 0x54 +#define SDR_CTRLGRP_LOWPWRACK_ADDR 0x58 + +/* Bitfield positions */ +#define SELFRSHREQ_POS 3 +#define SELFRSHREQ_MASK 0x8 + +#define SELFRFSHACK_POS 1 +#define SELFRFSHACK_MASK 0x2 + + .arch armv7-a + .text + .align 3 + + /* + * socfpga_sdram_self_refresh + * + * r0 : sdr_ctl_base_addr + * r1 : socfpga_scu_base_addr + * r2 : temp storage of register values + * r3 : loop counter + * r4 : temp storage of return value + * + * return value: lower 16 bits: loop count going into self refresh + * upper 16 bits: loop count exiting self refresh + */ +ENTRY(socfpga_sdram_self_refresh) + stmfd sp!, {r4} + + /* + * Enable SCU (snoop) standby mode. + * + * From the ARM Cortex-A9 MPCore Technical Reference Manual: + * "When set, SCU CLK is turned off when all processors are in WFI + * mode, there is no pending request on the ACP (if implemented), and + * there is no remaining activity in the SCU." + */ + ldr r2, [r1, #SOCFPGA_SCU_CTRL_OFFS] + orr r2, r2, #SCU_STANDBY_ENA + str r2, [r1, #SOCFPGA_SCU_CTRL_OFFS] + + /* Enable dynamic clock gating in the Power Control Register. */ + mrc p15, 0, r2, c15, c0, 0 + orr r2, r2, #1 + mcr p15, 0, r2, c15, c0, 0 + + /* Enable self refresh: set sdr.ctrlgrp.lowpwreq.selfrshreq = 1 */ + ldr r2, [r0, #SDR_CTRLGRP_LOWPWREQ_ADDR] + orr r2, r2, #SELFRSHREQ_MASK + str r2, [r0, #SDR_CTRLGRP_LOWPWREQ_ADDR] + + /* Poll until sdr.ctrlgrp.lowpwrack.selfrfshack == 1 or hit max loops */ + mov r3, #0 +while_ack_0: + ldr r2, [r0, #SDR_CTRLGRP_LOWPWRACK_ADDR] + and r2, r2, #SELFRFSHACK_MASK + cmp r2, #SELFRFSHACK_MASK + beq ack_1 + + add r3, #1 + cmp r3, #MAX_LOOP_COUNT + bne while_ack_0 + +ack_1: + mov r4, r3 + + /* + * Execute an ISB instruction to ensure that all of the + * CP15 register changes have been committed. + */ + isb + + /* + * Execute a barrier instruction to ensure that all cache, + * TLB and branch predictor maintenance operations issued + * by any CPU in the cluster have completed. + */ + dsb + dmb + + wfi + + /* Disable self-refresh: set sdr.ctrlgrp.lowpwreq.selfrshreq = 0 */ + ldr r2, [r0, #SDR_CTRLGRP_LOWPWREQ_ADDR] + bic r2, r2, #SELFRSHREQ_MASK + str r2, [r0, #SDR_CTRLGRP_LOWPWREQ_ADDR] + + /* Poll until sdr.ctrlgrp.lowpwrack.selfrfshack == 0 or hit max loops */ + mov r3, #0 +while_ack_1: + ldr r2, [r0, #SDR_CTRLGRP_LOWPWRACK_ADDR] + and r2, r2, #SELFRFSHACK_MASK + cmp r2, #SELFRFSHACK_MASK + bne ack_0 + + add r3, #1 + cmp r3, #MAX_LOOP_COUNT + bne while_ack_1 + +ack_0: + /* + * Prepare return value: + * Shift loop count for exiting self refresh into upper 16 bits. + * Leave loop count for requesting self refresh in lower 16 bits. + */ + mov r3, r3, lsl #16 + add r4, r4, r3 + + /* Disable dynamic clock gating in the Power Control Register. */ + mrc p15, 0, r2, c15, c0, 0 + bic r2, r2, #1 + mcr p15, 0, r2, c15, c0, 0 + + /* Disable SCU standby mode */ + ldr r2, [r1, #SOCFPGA_SCU_CTRL_OFFS] + bic r2, r2, #SCU_STANDBY_ENA + str r2, [r1, #SOCFPGA_SCU_CTRL_OFFS] + + mov r0, r4 @ return value + ldmfd sp!, {r4} + bx lr @ return + +ENDPROC(socfpga_sdram_self_refresh) +ENTRY(socfpga_sdram_self_refresh_sz) + .word . - socfpga_sdram_self_refresh diff --git a/arch/arm/mach-socfpga/socfpga.c b/arch/arm/mach-socfpga/socfpga.c index adbf383..34b4cc5 100644 --- a/arch/arm/mach-socfpga/socfpga.c +++ b/arch/arm/mach-socfpga/socfpga.c @@ -30,6 +30,7 @@ void __iomem *socfpga_scu_base_addr = ((void __iomem *)(SOCFPGA_SCU_VIRT_BASE)); void __iomem *sys_manager_base_addr; void __iomem *rst_manager_base_addr; unsigned long cpu1start_addr; +void __iomem *sdr_ctl_base_addr; static struct map_desc scu_io_desc __initdata = { .virtual = SOCFPGA_SCU_VIRT_BASE, @@ -77,6 +78,15 @@ void __init socfpga_sysmgr_init(void) np = of_find_compatible_node(NULL, NULL, "altr,rst-mgr"); rst_manager_base_addr = of_iomap(np, 0); + + np = of_find_compatible_node(NULL, NULL, "altr,sdr-ctl"); + if (!np) { + pr_err("SOCFPGA: Unable to find sdr-ctl\n"); + return; + } + + sdr_ctl_base_addr = of_iomap(np, 0); + WARN_ON(!sdr_ctl_base_addr); } static void __init socfpga_init_irq(void) -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
