arch/arm/mach-ux500/cpu-db8500.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2008-2009 ST-Ericsson SA
   4  *
   5  * Author: Srinidhi KASAGAR <srinidhi.kasagar@stericsson.com>
   6  */
   7 #include <linux/types.h>
   8 #include <linux/init.h>
   9 #include <linux/device.h>
  10 #include <linux/amba/bus.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/irq.h>
  13 #include <linux/irqchip.h>
  14 #include <linux/irqchip/arm-gic.h>
  15 #include <linux/mfd/dbx500-prcmu.h>
  16 #include <linux/platform_data/arm-ux500-pm.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/io.h>
  19 #include <linux/of.h>
  20 #include <linux/of_address.h>
  21 #include <linux/of_platform.h>
  22 #include <linux/regulator/machine.h>
  23
  24 #include <asm/outercache.h>
  25 #include <asm/hardware/cache-l2x0.h>
  26 #include <asm/mach/map.h>
  27 #include <asm/mach/arch.h>
  28
  29 static int __init ux500_l2x0_unlock(void)
  30 {
  31         int i;
  32         struct device_node *np;
  33         void __iomem *l2x0_base;
  34
  35         np = of_find_compatible_node(NULL, NULL, "arm,pl310-cache");
  36         l2x0_base = of_iomap(np, 0);
  37         of_node_put(np);
  38         if (!l2x0_base)
  39                 return -ENODEV;
  40
  41         /*
  42          * Unlock Data and Instruction Lock if locked. Ux500 U-Boot versions
  43          * apparently locks both caches before jumping to the kernel. The
  44          * l2x0 core will not touch the unlock registers if the l2x0 is
  45          * already enabled, so we do it right here instead. The PL310 has
  46          * 8 sets of registers, one per possible CPU.
  47          */
  48         for (i = 0; i < 8; i++) {
  49                 writel_relaxed(0x0, l2x0_base + L2X0_LOCKDOWN_WAY_D_BASE +
  50                                i * L2X0_LOCKDOWN_STRIDE);
  51                 writel_relaxed(0x0, l2x0_base + L2X0_LOCKDOWN_WAY_I_BASE +
  52                                i * L2X0_LOCKDOWN_STRIDE);
  53         }
  54         iounmap(l2x0_base);
  55         return 0;
  56 }
  57
  58 static void ux500_l2c310_write_sec(unsigned long val, unsigned reg)
  59 {
  60         /*
  61          * We can't write to secure registers as we are in non-secure
  62          * mode, until we have some SMI service available.
  63          */
  64 }
  65
  66 /*
  67  * FIXME: Should we set up the GPIO domain here?
  68  *
  69  * The problem is that we cannot put the interrupt resources into the platform
  70  * device until the irqdomain has been added. Right now, we set the GIC interrupt
  71  * domain from init_irq(), then load the gpio driver from
  72  * core_initcall(nmk_gpio_init) and add the platform devices from
  73  * arch_initcall(customize_machine).
  74  *
  75  * This feels fragile because it depends on the gpio device getting probed
  76  * _before_ any device uses the gpio interrupts.
  77 */
  78 static void __init ux500_init_irq(void)
  79 {
  80         struct device_node *np;
  81         struct resource r;
  82
  83         irqchip_init();
  84         prcmu_early_init();
  85         np = of_find_compatible_node(NULL, NULL, "stericsson,db8500-prcmu");
  86         of_address_to_resource(np, 0, &r);
  87         of_node_put(np);
  88         if (!r.start) {
  89                 pr_err("could not find PRCMU base resource\n");
  90                 return;
  91         }
  92         ux500_pm_init(r.start, r.end-r.start);
  93
  94         /* Unlock before init */
  95         ux500_l2x0_unlock();
  96         outer_cache.write_sec = ux500_l2c310_write_sec;
  97 }
  98
  99 static void ux500_restart(enum reboot_mode mode, const char *cmd)
 100 {
 101         local_irq_disable();
 102         local_fiq_disable();
 103
 104         prcmu_system_reset(0);
 105 }
 106
 107 static const struct of_device_id u8500_local_bus_nodes[] = {
 108         /* only create devices below soc node */
 109         { .compatible = "stericsson,db8500", },
 110         { .compatible = "simple-bus"},
 111         { },
 112 };
 113
 114 static void __init u8500_init_machine(void)
 115 {
 116         of_platform_populate(NULL, u8500_local_bus_nodes,
 117                              NULL, NULL);
 118 }
 119
 120 static const char * stericsson_dt_platform_compat[] = {
 121         "st-ericsson,u8500",
 122         "st-ericsson,u9500",
 123         NULL,
 124 };
 125
 126 DT_MACHINE_START(U8500_DT, "ST-Ericsson Ux5x0 platform (Device Tree Support)")
 127         .l2c_aux_val    = 0,
 128         .l2c_aux_mask   = ~0,
 129         .init_irq       = ux500_init_irq,
 130         .init_machine   = u8500_init_machine,
 131         .dt_compat      = stericsson_dt_platform_compat,
 132         .restart        = ux500_restart,
 133 MACHINE_END