diff options
Diffstat (limited to '')
| -rw-r--r-- | arch/arm/mach-zynq/Kconfig | 17 | ||||
| -rw-r--r-- | arch/arm/mach-zynq/Makefile | 8 | ||||
| -rw-r--r-- | arch/arm/mach-zynq/common.c | 200 | ||||
| -rw-r--r-- | arch/arm/mach-zynq/common.h | 43 | ||||
| -rw-r--r-- | arch/arm/mach-zynq/headsmp.S | 23 | ||||
| -rw-r--r-- | arch/arm/mach-zynq/platsmp.c | 163 | ||||
| -rw-r--r-- | arch/arm/mach-zynq/pm.c | 71 | ||||
| -rw-r--r-- | arch/arm/mach-zynq/slcr.c | 233 |
8 files changed, 758 insertions, 0 deletions
diff --git a/arch/arm/mach-zynq/Kconfig b/arch/arm/mach-zynq/Kconfig new file mode 100644 index 000000000..05be5aa9b --- /dev/null +++ b/arch/arm/mach-zynq/Kconfig @@ -0,0 +1,17 @@ +# SPDX-License-Identifier: GPL-2.0 +config ARCH_ZYNQ + bool "Xilinx Zynq ARM Cortex A9 Platform" + depends on ARCH_MULTI_V7 + select ARCH_HAS_RESET_CONTROLLER + select ARM_AMBA + select ARM_GIC + select ARM_GLOBAL_TIMER + select CADENCE_TTC_TIMER + select HAVE_ARM_SCU if SMP + select HAVE_ARM_TWD if SMP + select MFD_SYSCON + select PINCTRL + select PINCTRL_ZYNQ + select SOC_BUS + help + Support for Xilinx Zynq ARM Cortex A9 Platform diff --git a/arch/arm/mach-zynq/Makefile b/arch/arm/mach-zynq/Makefile new file mode 100644 index 000000000..9df74cd85 --- /dev/null +++ b/arch/arm/mach-zynq/Makefile @@ -0,0 +1,8 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# Makefile for the linux kernel. +# + +# Common support +obj-y := common.o slcr.o pm.o +obj-$(CONFIG_SMP) += headsmp.o platsmp.o diff --git a/arch/arm/mach-zynq/common.c b/arch/arm/mach-zynq/common.c new file mode 100644 index 000000000..15e8a321a --- /dev/null +++ b/arch/arm/mach-zynq/common.c @@ -0,0 +1,200 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file contains common code that is intended to be used across + * boards so that it's not replicated. + * + * Copyright (C) 2011 Xilinx + */ + +#include <linux/init.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/cpumask.h> +#include <linux/platform_device.h> +#include <linux/clk.h> +#include <linux/clk/zynq.h> +#include <linux/clocksource.h> +#include <linux/of_address.h> +#include <linux/of_clk.h> +#include <linux/of_irq.h> +#include <linux/of_platform.h> +#include <linux/of.h> +#include <linux/memblock.h> +#include <linux/irqchip.h> +#include <linux/irqchip/arm-gic.h> +#include <linux/slab.h> +#include <linux/sys_soc.h> +#include <linux/pgtable.h> + +#include <asm/mach/arch.h> +#include <asm/mach/map.h> +#include <asm/mach/time.h> +#include <asm/mach-types.h> +#include <asm/page.h> +#include <asm/smp_scu.h> +#include <asm/system_info.h> +#include <asm/hardware/cache-l2x0.h> + +#include "common.h" + +#define ZYNQ_DEVCFG_MCTRL 0x80 +#define ZYNQ_DEVCFG_PS_VERSION_SHIFT 28 +#define ZYNQ_DEVCFG_PS_VERSION_MASK 0xF + +void __iomem *zynq_scu_base; + +/** + * zynq_memory_init - Initialize special memory + * + * We need to stop things allocating the low memory as DMA can't work in + * the 1st 512K of memory. + */ +static void __init zynq_memory_init(void) +{ + if (!__pa(PAGE_OFFSET)) + memblock_reserve(__pa(PAGE_OFFSET), 0x80000); +} + +static struct platform_device zynq_cpuidle_device = { + .name = "cpuidle-zynq", +}; + +/** + * zynq_get_revision - Get Zynq silicon revision + * + * Return: Silicon version or -1 otherwise + */ +static int __init zynq_get_revision(void) +{ + struct device_node *np; + void __iomem *zynq_devcfg_base; + u32 revision; + + np = of_find_compatible_node(NULL, NULL, "xlnx,zynq-devcfg-1.0"); + if (!np) { + pr_err("%s: no devcfg node found\n", __func__); + return -1; + } + + zynq_devcfg_base = of_iomap(np, 0); + of_node_put(np); + if (!zynq_devcfg_base) { + pr_err("%s: Unable to map I/O memory\n", __func__); + return -1; + } + + revision = readl(zynq_devcfg_base + ZYNQ_DEVCFG_MCTRL); + revision >>= ZYNQ_DEVCFG_PS_VERSION_SHIFT; + revision &= ZYNQ_DEVCFG_PS_VERSION_MASK; + + iounmap(zynq_devcfg_base); + + return revision; +} + +static void __init zynq_init_late(void) +{ + zynq_core_pm_init(); + zynq_pm_late_init(); +} + +/** + * zynq_init_machine - System specific initialization, intended to be + * called from board specific initialization. + */ +static void __init zynq_init_machine(void) +{ + struct soc_device_attribute *soc_dev_attr; + struct soc_device *soc_dev; + struct device *parent = NULL; + + soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL); + if (!soc_dev_attr) + goto out; + + system_rev = zynq_get_revision(); + + soc_dev_attr->family = kasprintf(GFP_KERNEL, "Xilinx Zynq"); + soc_dev_attr->revision = kasprintf(GFP_KERNEL, "0x%x", system_rev); + soc_dev_attr->soc_id = kasprintf(GFP_KERNEL, "0x%x", + zynq_slcr_get_device_id()); + + soc_dev = soc_device_register(soc_dev_attr); + if (IS_ERR(soc_dev)) { + kfree(soc_dev_attr->family); + kfree(soc_dev_attr->revision); + kfree(soc_dev_attr->soc_id); + kfree(soc_dev_attr); + goto out; + } + + parent = soc_device_to_device(soc_dev); + +out: + /* + * Finished with the static registrations now; fill in the missing + * devices + */ + of_platform_default_populate(NULL, NULL, parent); + + platform_device_register(&zynq_cpuidle_device); +} + +static void __init zynq_timer_init(void) +{ + zynq_clock_init(); + of_clk_init(NULL); + timer_probe(); +} + +static struct map_desc zynq_cortex_a9_scu_map __initdata = { + .length = SZ_256, + .type = MT_DEVICE, +}; + +static void __init zynq_scu_map_io(void) +{ + unsigned long base; + + base = scu_a9_get_base(); + zynq_cortex_a9_scu_map.pfn = __phys_to_pfn(base); + /* Expected address is in vmalloc area that's why simple assign here */ + zynq_cortex_a9_scu_map.virtual = base; + iotable_init(&zynq_cortex_a9_scu_map, 1); + zynq_scu_base = (void __iomem *)base; + BUG_ON(!zynq_scu_base); +} + +/** + * zynq_map_io - Create memory mappings needed for early I/O. + */ +static void __init zynq_map_io(void) +{ + debug_ll_io_init(); + zynq_scu_map_io(); +} + +static void __init zynq_irq_init(void) +{ + zynq_early_slcr_init(); + irqchip_init(); +} + +static const char * const zynq_dt_match[] = { + "xlnx,zynq-7000", + NULL +}; + +DT_MACHINE_START(XILINX_EP107, "Xilinx Zynq Platform") + /* 64KB way size, 8-way associativity, parity disabled */ + .l2c_aux_val = 0x00400000, + .l2c_aux_mask = 0xffbfffff, + .smp = smp_ops(zynq_smp_ops), + .map_io = zynq_map_io, + .init_irq = zynq_irq_init, + .init_machine = zynq_init_machine, + .init_late = zynq_init_late, + .init_time = zynq_timer_init, + .dt_compat = zynq_dt_match, + .reserve = zynq_memory_init, +MACHINE_END diff --git a/arch/arm/mach-zynq/common.h b/arch/arm/mach-zynq/common.h new file mode 100644 index 000000000..60e662324 --- /dev/null +++ b/arch/arm/mach-zynq/common.h @@ -0,0 +1,43 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * This file contains common function prototypes to avoid externs + * in the c files. + * + * Copyright (C) 2011 Xilinx + */ + +#ifndef __MACH_ZYNQ_COMMON_H__ +#define __MACH_ZYNQ_COMMON_H__ + +extern int zynq_slcr_init(void); +extern int zynq_early_slcr_init(void); +extern void zynq_slcr_cpu_stop(int cpu); +extern void zynq_slcr_cpu_start(int cpu); +extern bool zynq_slcr_cpu_state_read(int cpu); +extern void zynq_slcr_cpu_state_write(int cpu, bool die); +extern u32 zynq_slcr_get_device_id(void); + +#ifdef CONFIG_SMP +extern char zynq_secondary_trampoline; +extern char zynq_secondary_trampoline_jump; +extern char zynq_secondary_trampoline_end; +extern int zynq_cpun_start(u32 address, int cpu); +extern const struct smp_operations zynq_smp_ops; +#endif + +extern void __iomem *zynq_scu_base; + +void zynq_pm_late_init(void); + +static inline void zynq_core_pm_init(void) +{ + /* A9 clock gating */ + asm volatile ("mrc p15, 0, r12, c15, c0, 0\n" + "orr r12, r12, #1\n" + "mcr p15, 0, r12, c15, c0, 0\n" + : /* no outputs */ + : /* no inputs */ + : "r12"); +} + +#endif diff --git a/arch/arm/mach-zynq/headsmp.S b/arch/arm/mach-zynq/headsmp.S new file mode 100644 index 000000000..3449e0d1f --- /dev/null +++ b/arch/arm/mach-zynq/headsmp.S @@ -0,0 +1,23 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (c) 2013 Steffen Trumtrar <s.trumtrar@pengutronix.de> + * Copyright (c) 2012-2013 Xilinx + */ +#include <linux/linkage.h> +#include <linux/init.h> +#include <asm/assembler.h> + + .arm + +ENTRY(zynq_secondary_trampoline) +ARM_BE8(setend be) @ ensure we are in BE8 mode + ldr r0, zynq_secondary_trampoline_jump +ARM_BE8(rev r0, r0) + bx r0 +.globl zynq_secondary_trampoline_jump +zynq_secondary_trampoline_jump: + /* Space for jumping address */ + .word 0 /* cpu 1 */ +.globl zynq_secondary_trampoline_end +zynq_secondary_trampoline_end: +ENDPROC(zynq_secondary_trampoline) diff --git a/arch/arm/mach-zynq/platsmp.c b/arch/arm/mach-zynq/platsmp.c new file mode 100644 index 000000000..68ec303fa --- /dev/null +++ b/arch/arm/mach-zynq/platsmp.c @@ -0,0 +1,163 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file contains Xilinx specific SMP code, used to start up + * the second processor. + * + * Copyright (C) 2011-2013 Xilinx + * + * based on linux/arch/arm/mach-realview/platsmp.c + * + * Copyright (C) 2002 ARM Ltd. + */ + +#include <linux/export.h> +#include <linux/jiffies.h> +#include <linux/init.h> +#include <linux/io.h> +#include <asm/cacheflush.h> +#include <asm/smp_plat.h> +#include <asm/smp_scu.h> +#include <linux/irqchip/arm-gic.h> +#include "common.h" + +/* + * Store number of cores in the system + * Because of scu_get_core_count() must be in __init section and can't + * be called from zynq_cpun_start() because it is not in __init section. + */ +static int ncores; + +int zynq_cpun_start(u32 address, int cpu) +{ + u32 trampoline_code_size = &zynq_secondary_trampoline_end - + &zynq_secondary_trampoline; + u32 phy_cpuid = cpu_logical_map(cpu); + + /* MS: Expectation that SLCR are directly map and accessible */ + /* Not possible to jump to non aligned address */ + if (!(address & 3) && (!address || (address >= trampoline_code_size))) { + /* Store pointer to ioremap area which points to address 0x0 */ + static u8 __iomem *zero; + u32 trampoline_size = &zynq_secondary_trampoline_jump - + &zynq_secondary_trampoline; + + zynq_slcr_cpu_stop(phy_cpuid); + if (address) { + if (__pa(PAGE_OFFSET)) { + zero = ioremap(0, trampoline_code_size); + if (!zero) { + pr_warn("BOOTUP jump vectors not accessible\n"); + return -1; + } + } else { + zero = (__force u8 __iomem *)PAGE_OFFSET; + } + + /* + * This is elegant way how to jump to any address + * 0x0: Load address at 0x8 to r0 + * 0x4: Jump by mov instruction + * 0x8: Jumping address + */ + memcpy_toio(zero, &zynq_secondary_trampoline, + trampoline_size); + writel(address, zero + trampoline_size); + + flush_cache_all(); + outer_flush_range(0, trampoline_code_size); + smp_wmb(); + + if (__pa(PAGE_OFFSET)) + iounmap(zero); + } + zynq_slcr_cpu_start(phy_cpuid); + + return 0; + } + + pr_warn("Can't start CPU%d: Wrong starting address %x\n", cpu, address); + + return -1; +} +EXPORT_SYMBOL(zynq_cpun_start); + +static int zynq_boot_secondary(unsigned int cpu, struct task_struct *idle) +{ + return zynq_cpun_start(__pa_symbol(secondary_startup_arm), cpu); +} + +/* + * Initialise the CPU possible map early - this describes the CPUs + * which may be present or become present in the system. + */ +static void __init zynq_smp_init_cpus(void) +{ + int i; + + ncores = scu_get_core_count(zynq_scu_base); + + for (i = 0; i < ncores && i < CONFIG_NR_CPUS; i++) + set_cpu_possible(i, true); +} + +static void __init zynq_smp_prepare_cpus(unsigned int max_cpus) +{ + scu_enable(zynq_scu_base); +} + +/** + * zynq_secondary_init - Initialize secondary CPU cores + * @cpu: CPU that is initialized + * + * This function is in the hotplug path. Don't move it into the + * init section!! + */ +static void zynq_secondary_init(unsigned int cpu) +{ + zynq_core_pm_init(); +} + +#ifdef CONFIG_HOTPLUG_CPU +static int zynq_cpu_kill(unsigned cpu) +{ + unsigned long timeout = jiffies + msecs_to_jiffies(50); + + while (zynq_slcr_cpu_state_read(cpu)) + if (time_after(jiffies, timeout)) + return 0; + + zynq_slcr_cpu_stop(cpu); + return 1; +} + +/** + * zynq_cpu_die - Let a CPU core die + * @cpu: Dying CPU + * + * Platform-specific code to shutdown a CPU. + * Called with IRQs disabled on the dying CPU. + */ +static void zynq_cpu_die(unsigned int cpu) +{ + zynq_slcr_cpu_state_write(cpu, true); + + /* + * there is no power-control hardware on this platform, so all + * we can do is put the core into WFI; this is safe as the calling + * code will have already disabled interrupts + */ + for (;;) + cpu_do_idle(); +} +#endif + +const struct smp_operations zynq_smp_ops __initconst = { + .smp_init_cpus = zynq_smp_init_cpus, + .smp_prepare_cpus = zynq_smp_prepare_cpus, + .smp_boot_secondary = zynq_boot_secondary, + .smp_secondary_init = zynq_secondary_init, +#ifdef CONFIG_HOTPLUG_CPU + .cpu_die = zynq_cpu_die, + .cpu_kill = zynq_cpu_kill, +#endif +}; diff --git a/arch/arm/mach-zynq/pm.c b/arch/arm/mach-zynq/pm.c new file mode 100644 index 000000000..8ba450ab5 --- /dev/null +++ b/arch/arm/mach-zynq/pm.c @@ -0,0 +1,71 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Zynq power management + * + * Copyright (C) 2012 - 2014 Xilinx + * + * Sören Brinkmann <soren.brinkmann@xilinx.com> + */ + +#include <linux/io.h> +#include <linux/of_address.h> +#include <linux/of_device.h> +#include "common.h" + +/* register offsets */ +#define DDRC_CTRL_REG1_OFFS 0x60 +#define DDRC_DRAM_PARAM_REG3_OFFS 0x20 + +/* bitfields */ +#define DDRC_CLOCKSTOP_MASK BIT(23) +#define DDRC_SELFREFRESH_MASK BIT(12) + +static void __iomem *ddrc_base; + +/** + * zynq_pm_ioremap() - Create IO mappings + * @comp: DT compatible string + * Return: Pointer to the mapped memory or NULL. + * + * Remap the memory region for a compatible DT node. + */ +static void __iomem *zynq_pm_ioremap(const char *comp) +{ + struct device_node *np; + void __iomem *base = NULL; + + np = of_find_compatible_node(NULL, NULL, comp); + if (np) { + base = of_iomap(np, 0); + of_node_put(np); + } else { + pr_warn("%s: no compatible node found for '%s'\n", __func__, + comp); + } + + return base; +} + +/** + * zynq_pm_late_init() - Power management init + * + * Initialization of power management related features and infrastructure. + */ +void __init zynq_pm_late_init(void) +{ + u32 reg; + + ddrc_base = zynq_pm_ioremap("xlnx,zynq-ddrc-a05"); + if (!ddrc_base) { + pr_warn("%s: Unable to map DDRC IO memory.\n", __func__); + } else { + /* + * Enable DDRC clock stop feature. The HW takes care of + * entering/exiting the correct mode depending + * on activity state. + */ + reg = readl(ddrc_base + DDRC_DRAM_PARAM_REG3_OFFS); + reg |= DDRC_CLOCKSTOP_MASK; + writel(reg, ddrc_base + DDRC_DRAM_PARAM_REG3_OFFS); + } +} diff --git a/arch/arm/mach-zynq/slcr.c b/arch/arm/mach-zynq/slcr.c new file mode 100644 index 000000000..9765b3f4c --- /dev/null +++ b/arch/arm/mach-zynq/slcr.c @@ -0,0 +1,233 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Xilinx SLCR driver + * + * Copyright (c) 2011-2013 Xilinx Inc. + */ + +#include <linux/io.h> +#include <linux/reboot.h> +#include <linux/mfd/syscon.h> +#include <linux/of_address.h> +#include <linux/regmap.h> +#include <linux/clk/zynq.h> +#include "common.h" + +/* register offsets */ +#define SLCR_UNLOCK_OFFSET 0x8 /* SCLR unlock register */ +#define SLCR_PS_RST_CTRL_OFFSET 0x200 /* PS Software Reset Control */ +#define SLCR_A9_CPU_RST_CTRL_OFFSET 0x244 /* CPU Software Reset Control */ +#define SLCR_REBOOT_STATUS_OFFSET 0x258 /* PS Reboot Status */ +#define SLCR_PSS_IDCODE 0x530 /* PS IDCODE */ +#define SLCR_L2C_RAM 0xA1C /* L2C_RAM in AR#54190 */ + +#define SLCR_UNLOCK_MAGIC 0xDF0D +#define SLCR_A9_CPU_CLKSTOP 0x10 +#define SLCR_A9_CPU_RST 0x1 +#define SLCR_PSS_IDCODE_DEVICE_SHIFT 12 +#define SLCR_PSS_IDCODE_DEVICE_MASK 0x1F + +static void __iomem *zynq_slcr_base; +static struct regmap *zynq_slcr_regmap; + +/** + * zynq_slcr_write - Write to a register in SLCR block + * + * @val: Value to write to the register + * @offset: Register offset in SLCR block + * + * Return: a negative value on error, 0 on success + */ +static int zynq_slcr_write(u32 val, u32 offset) +{ + return regmap_write(zynq_slcr_regmap, offset, val); +} + +/** + * zynq_slcr_read - Read a register in SLCR block + * + * @val: Pointer to value to be read from SLCR + * @offset: Register offset in SLCR block + * + * Return: a negative value on error, 0 on success + */ +static int zynq_slcr_read(u32 *val, u32 offset) +{ + return regmap_read(zynq_slcr_regmap, offset, val); +} + +/** + * zynq_slcr_unlock - Unlock SLCR registers + * + * Return: a negative value on error, 0 on success + */ +static inline int zynq_slcr_unlock(void) +{ + zynq_slcr_write(SLCR_UNLOCK_MAGIC, SLCR_UNLOCK_OFFSET); + + return 0; +} + +/** + * zynq_slcr_get_device_id - Read device code id + * + * Return: Device code id + */ +u32 zynq_slcr_get_device_id(void) +{ + u32 val; + + zynq_slcr_read(&val, SLCR_PSS_IDCODE); + val >>= SLCR_PSS_IDCODE_DEVICE_SHIFT; + val &= SLCR_PSS_IDCODE_DEVICE_MASK; + + return val; +} + +/** + * zynq_slcr_system_restart - Restart the entire system. + * + * @nb: Pointer to restart notifier block (unused) + * @action: Reboot mode (unused) + * @data: Restart handler private data (unused) + * + * Return: 0 always + */ +static +int zynq_slcr_system_restart(struct notifier_block *nb, + unsigned long action, void *data) +{ + u32 reboot; + + /* + * Clear 0x0F000000 bits of reboot status register to workaround + * the FSBL not loading the bitstream after soft-reboot + * This is a temporary solution until we know more. + */ + zynq_slcr_read(&reboot, SLCR_REBOOT_STATUS_OFFSET); + zynq_slcr_write(reboot & 0xF0FFFFFF, SLCR_REBOOT_STATUS_OFFSET); + zynq_slcr_write(1, SLCR_PS_RST_CTRL_OFFSET); + return 0; +} + +static struct notifier_block zynq_slcr_restart_nb = { + .notifier_call = zynq_slcr_system_restart, + .priority = 192, +}; + +/** + * zynq_slcr_cpu_start - Start cpu + * @cpu: cpu number + */ +void zynq_slcr_cpu_start(int cpu) +{ + u32 reg; + + zynq_slcr_read(®, SLCR_A9_CPU_RST_CTRL_OFFSET); + reg &= ~(SLCR_A9_CPU_RST << cpu); + zynq_slcr_write(reg, SLCR_A9_CPU_RST_CTRL_OFFSET); + reg &= ~(SLCR_A9_CPU_CLKSTOP << cpu); + zynq_slcr_write(reg, SLCR_A9_CPU_RST_CTRL_OFFSET); + + zynq_slcr_cpu_state_write(cpu, false); +} + +/** + * zynq_slcr_cpu_stop - Stop cpu + * @cpu: cpu number + */ +void zynq_slcr_cpu_stop(int cpu) +{ + u32 reg; + + zynq_slcr_read(®, SLCR_A9_CPU_RST_CTRL_OFFSET); + reg |= (SLCR_A9_CPU_CLKSTOP | SLCR_A9_CPU_RST) << cpu; + zynq_slcr_write(reg, SLCR_A9_CPU_RST_CTRL_OFFSET); +} + +/** + * zynq_slcr_cpu_state - Read/write cpu state + * @cpu: cpu number + * + * SLCR_REBOOT_STATUS save upper 2 bits (31/30 cpu states for cpu0 and cpu1) + * 0 means cpu is running, 1 cpu is going to die. + * + * Return: true if cpu is running, false if cpu is going to die + */ +bool zynq_slcr_cpu_state_read(int cpu) +{ + u32 state; + + state = readl(zynq_slcr_base + SLCR_REBOOT_STATUS_OFFSET); + state &= 1 << (31 - cpu); + + return !state; +} + +/** + * zynq_slcr_cpu_state - Read/write cpu state + * @cpu: cpu number + * @die: cpu state - true if cpu is going to die + * + * SLCR_REBOOT_STATUS save upper 2 bits (31/30 cpu states for cpu0 and cpu1) + * 0 means cpu is running, 1 cpu is going to die. + */ +void zynq_slcr_cpu_state_write(int cpu, bool die) +{ + u32 state, mask; + + state = readl(zynq_slcr_base + SLCR_REBOOT_STATUS_OFFSET); + mask = 1 << (31 - cpu); + if (die) + state |= mask; + else + state &= ~mask; + writel(state, zynq_slcr_base + SLCR_REBOOT_STATUS_OFFSET); +} + +/** + * zynq_early_slcr_init - Early slcr init function + * + * Return: 0 on success, negative errno otherwise. + * + * Called very early during boot from platform code to unlock SLCR. + */ +int __init zynq_early_slcr_init(void) +{ + struct device_node *np; + + np = of_find_compatible_node(NULL, NULL, "xlnx,zynq-slcr"); + if (!np) { + pr_err("%s: no slcr node found\n", __func__); + BUG(); + } + + zynq_slcr_base = of_iomap(np, 0); + if (!zynq_slcr_base) { + pr_err("%s: Unable to map I/O memory\n", __func__); + BUG(); + } + + np->data = (__force void *)zynq_slcr_base; + + zynq_slcr_regmap = syscon_regmap_lookup_by_compatible("xlnx,zynq-slcr"); + if (IS_ERR(zynq_slcr_regmap)) { + pr_err("%s: failed to find zynq-slcr\n", __func__); + of_node_put(np); + return -ENODEV; + } + + /* unlock the SLCR so that registers can be changed */ + zynq_slcr_unlock(); + + /* See AR#54190 design advisory */ + regmap_update_bits(zynq_slcr_regmap, SLCR_L2C_RAM, 0x70707, 0x20202); + + register_restart_handler(&zynq_slcr_restart_nb); + + pr_info("%pOFn mapped to %p\n", np, zynq_slcr_base); + + of_node_put(np); + + return 0; +} |