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

   1 /*
   2  * Copyright (C) 2008-2009 ST-Ericsson SA
   3  *
   4  * Author: Srinidhi KASAGAR <srinidhi.kasagar@stericsson.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2, as
   8  * published by the Free Software Foundation.
   9  *
  10  */
  11 #include <linux/types.h>
  12 #include <linux/init.h>
  13 #include <linux/device.h>
  14 #include <linux/amba/bus.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/irq.h>
  17 #include <linux/irqchip.h>
  18 #include <linux/irqchip/arm-gic.h>
  19 #include <linux/mfd/dbx500-prcmu.h>
  20 #include <linux/platform_data/arm-ux500-pm.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/io.h>
  23 #include <linux/of.h>
  24 #include <linux/of_address.h>
  25 #include <linux/of_platform.h>
  26 #include <linux/perf/arm_pmu.h>
  27 #include <linux/regulator/machine.h>
  28
  29 #include <asm/outercache.h>
  30 #include <asm/hardware/cache-l2x0.h>
  31 #include <asm/mach/map.h>
  32 #include <asm/mach/arch.h>
  33
  34 #include "db8500-regs.h"
  35 #include "pm_domains.h"
  36
  37 static int __init ux500_l2x0_unlock(void)
  38 {
  39         int i;
  40         struct device_node *np;
  41         void __iomem *l2x0_base;
  42
  43         np = of_find_compatible_node(NULL, NULL, "arm,pl310-cache");
  44         l2x0_base = of_iomap(np, 0);
  45         of_node_put(np);
  46         if (!l2x0_base)
  47                 return -ENODEV;
  48
  49         /*
  50          * Unlock Data and Instruction Lock if locked. Ux500 U-Boot versions
  51          * apparently locks both caches before jumping to the kernel. The
  52          * l2x0 core will not touch the unlock registers if the l2x0 is
  53          * already enabled, so we do it right here instead. The PL310 has
  54          * 8 sets of registers, one per possible CPU.
  55          */
  56         for (i = 0; i < 8; i++) {
  57                 writel_relaxed(0x0, l2x0_base + L2X0_LOCKDOWN_WAY_D_BASE +
  58                                i * L2X0_LOCKDOWN_STRIDE);
  59                 writel_relaxed(0x0, l2x0_base + L2X0_LOCKDOWN_WAY_I_BASE +
  60                                i * L2X0_LOCKDOWN_STRIDE);
  61         }
  62         iounmap(l2x0_base);
  63         return 0;
  64 }
  65
  66 static void ux500_l2c310_write_sec(unsigned long val, unsigned reg)
  67 {
  68         /*
  69          * We can't write to secure registers as we are in non-secure
  70          * mode, until we have some SMI service available.
  71          */
  72 }
  73
  74 /*
  75  * FIXME: Should we set up the GPIO domain here?
  76  *
  77  * The problem is that we cannot put the interrupt resources into the platform
  78  * device until the irqdomain has been added. Right now, we set the GIC interrupt
  79  * domain from init_irq(), then load the gpio driver from
  80  * core_initcall(nmk_gpio_init) and add the platform devices from
  81  * arch_initcall(customize_machine).
  82  *
  83  * This feels fragile because it depends on the gpio device getting probed
  84  * _before_ any device uses the gpio interrupts.
  85 */
  86 static void __init ux500_init_irq(void)
  87 {
  88         struct device_node *np;
  89         struct resource r;
  90
  91         irqchip_init();
  92         np = of_find_compatible_node(NULL, NULL, "stericsson,db8500-prcmu");
  93         of_address_to_resource(np, 0, &r);
  94         of_node_put(np);
  95         if (!r.start) {
  96                 pr_err("could not find PRCMU base resource\n");
  97                 return;
  98         }
  99         prcmu_early_init(r.start, r.end-r.start);
 100         ux500_pm_init(r.start, r.end-r.start);
 101
 102         /* Unlock before init */
 103         ux500_l2x0_unlock();
 104         outer_cache.write_sec = ux500_l2c310_write_sec;
 105 }
 106
 107 static void ux500_restart(enum reboot_mode mode, const char *cmd)
 108 {
 109         local_irq_disable();
 110         local_fiq_disable();
 111
 112         prcmu_system_reset(0);
 113 }
 114
 115 /*
 116  * The PMU IRQ lines of two cores are wired together into a single interrupt.
 117  * Bounce the interrupt to the other core if it's not ours.
 118  */
 119 static irqreturn_t db8500_pmu_handler(int irq, void *dev, irq_handler_t handler)
 120 {
 121         irqreturn_t ret = handler(irq, dev);
 122         int other = !smp_processor_id();
 123
 124         if (ret == IRQ_NONE && cpu_online(other))
 125                 irq_set_affinity(irq, cpumask_of(other));
 126
 127         /*
 128          * We should be able to get away with the amount of IRQ_NONEs we give,
 129          * while still having the spurious IRQ detection code kick in if the
 130          * interrupt really starts hitting spuriously.
 131          */
 132         return ret;
 133 }
 134
 135 static struct arm_pmu_platdata db8500_pmu_platdata = {
 136         .handle_irq             = db8500_pmu_handler,
 137         .irq_flags              = IRQF_NOBALANCING | IRQF_NO_THREAD,
 138 };
 139
 140 static struct of_dev_auxdata u8500_auxdata_lookup[] __initdata = {
 141         /* Requires call-back bindings. */
 142         OF_DEV_AUXDATA("arm,cortex-a9-pmu", 0, "arm-pmu", &db8500_pmu_platdata),
 143         {},
 144 };
 145
 146 static struct of_dev_auxdata u8540_auxdata_lookup[] __initdata = {
 147         OF_DEV_AUXDATA("stericsson,db8500-prcmu", 0x80157000, "db8500-prcmu", NULL),
 148         {},
 149 };
 150
 151 static const struct of_device_id u8500_local_bus_nodes[] = {
 152         /* only create devices below soc node */
 153         { .compatible = "stericsson,db8500", },
 154         { .compatible = "stericsson,db8500-prcmu", },
 155         { .compatible = "simple-bus"},
 156         { },
 157 };
 158
 159 static void __init u8500_init_machine(void)
 160 {
 161         /* Initialize ux500 power domains */
 162         ux500_pm_domains_init();
 163
 164         /* automatically probe child nodes of dbx5x0 devices */
 165         if (of_machine_is_compatible("st-ericsson,u8540"))
 166                 of_platform_populate(NULL, u8500_local_bus_nodes,
 167                                      u8540_auxdata_lookup, NULL);
 168         else
 169                 of_platform_populate(NULL, u8500_local_bus_nodes,
 170                                      u8500_auxdata_lookup, NULL);
 171 }
 172
 173 static const char * stericsson_dt_platform_compat[] = {
 174         "st-ericsson,u8500",
 175         "st-ericsson,u8540",
 176         "st-ericsson,u9500",
 177         "st-ericsson,u9540",
 178         NULL,
 179 };
 180
 181 DT_MACHINE_START(U8500_DT, "ST-Ericsson Ux5x0 platform (Device Tree Support)")
 182         .l2c_aux_val    = 0,
 183         .l2c_aux_mask   = ~0,
 184         .init_irq       = ux500_init_irq,
 185         .init_machine   = u8500_init_machine,
 186         .dt_compat      = stericsson_dt_platform_compat,
 187         .restart        = ux500_restart,
 188 MACHINE_END