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