root/arch/arm/mach-omap2/omap4-common.c

DEFINITIONS

1. omap4_mb
2. omap_interconnect_sync
3. omap4_sram_init
4. omap_barrier_reserve_memblock
5. omap_barriers_init
6. gic_dist_disable
7. gic_dist_enable
8. gic_dist_disabled
9. gic_timer_retrigger
10. omap4_get_l2cache_base
11. omap4_l2c310_write_sec
12. omap_l2_cache_init
13. omap4_get_sar_ram_base
14. omap4_sar_ram_init
15. omap_gic_of_init

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * OMAP4 specific common source file.
   4  *
   5  * Copyright (C) 2010 Texas Instruments, Inc.
   6  * Author:
   7  *      Santosh Shilimkar <santosh.shilimkar@ti.com>
   8  */
   9 
  10 #include <linux/kernel.h>
  11 #include <linux/init.h>
  12 #include <linux/io.h>
  13 #include <linux/irq.h>
  14 #include <linux/irqchip.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/memblock.h>
  17 #include <linux/of_irq.h>
  18 #include <linux/of_platform.h>
  19 #include <linux/export.h>
  20 #include <linux/irqchip/arm-gic.h>
  21 #include <linux/of_address.h>
  22 #include <linux/reboot.h>
  23 #include <linux/genalloc.h>
  24 
  25 #include <asm/hardware/cache-l2x0.h>
  26 #include <asm/mach/map.h>
  27 #include <asm/memblock.h>
  28 #include <asm/smp_twd.h>
  29 
  30 #include "omap-wakeupgen.h"
  31 #include "soc.h"
  32 #include "iomap.h"
  33 #include "common.h"
  34 #include "prminst44xx.h"
  35 #include "prcm_mpu44xx.h"
  36 #include "omap4-sar-layout.h"
  37 #include "omap-secure.h"
  38 #include "sram.h"
  39 
  40 #ifdef CONFIG_CACHE_L2X0
  41 static void __iomem *l2cache_base;
  42 #endif
  43 
  44 static void __iomem *sar_ram_base;
  45 static void __iomem *gic_dist_base_addr;
  46 static void __iomem *twd_base;
  47 
  48 #define IRQ_LOCALTIMER          29
  49 
  50 #ifdef CONFIG_OMAP_INTERCONNECT_BARRIER
  51 
  52 /* Used to implement memory barrier on DRAM path */
  53 #define OMAP4_DRAM_BARRIER_VA                   0xfe600000
  54 
  55 static void __iomem *dram_sync, *sram_sync;
  56 static phys_addr_t dram_sync_paddr;
  57 static u32 dram_sync_size;
  58 
  59 /*
  60  * The OMAP4 bus structure contains asynchronous bridges which can buffer
  61  * data writes from the MPU. These asynchronous bridges can be found on
  62  * paths between the MPU to EMIF, and the MPU to L3 interconnects.
  63  *
  64  * We need to be careful about re-ordering which can happen as a result
  65  * of different accesses being performed via different paths, and
  66  * therefore different asynchronous bridges.
  67  */
  68 
  69 /*
  70  * OMAP4 interconnect barrier which is called for each mb() and wmb().
  71  * This is to ensure that normal paths to DRAM (normal memory, cacheable
  72  * accesses) are properly synchronised with writes to DMA coherent memory
  73  * (normal memory, uncacheable) and device writes.
  74  *
  75  * The mb() and wmb() barriers only operate only on the MPU->MA->EMIF
  76  * path, as we need to ensure that data is visible to other system
  77  * masters prior to writes to those system masters being seen.
  78  *
  79  * Note: the SRAM path is not synchronised via mb() and wmb().
  80  */
  81 static void omap4_mb(void)
  82 {
  83         if (dram_sync)
  84                 writel_relaxed(0, dram_sync);
  85 }
  86 
  87 /*
  88  * OMAP4 Errata i688 - asynchronous bridge corruption when entering WFI.
  89  *
  90  * If a data is stalled inside asynchronous bridge because of back
  91  * pressure, it may be accepted multiple times, creating pointer
  92  * misalignment that will corrupt next transfers on that data path until
  93  * next reset of the system. No recovery procedure once the issue is hit,
  94  * the path remains consistently broken.
  95  *
  96  * Async bridges can be found on paths between MPU to EMIF and MPU to L3
  97  * interconnects.
  98  *
  99  * This situation can happen only when the idle is initiated by a Master
 100  * Request Disconnection (which is trigged by software when executing WFI
 101  * on the CPU).
 102  *
 103  * The work-around for this errata needs all the initiators connected
 104  * through an async bridge to ensure that data path is properly drained
 105  * before issuing WFI. This condition will be met if one Strongly ordered
 106  * access is performed to the target right before executing the WFI.
 107  *
 108  * In MPU case, L3 T2ASYNC FIFO and DDR T2ASYNC FIFO needs to be drained.
 109  * IO barrier ensure that there is no synchronisation loss on initiators
 110  * operating on both interconnect port simultaneously.
 111  *
 112  * This is a stronger version of the OMAP4 memory barrier below, and
 113  * operates on both the MPU->MA->EMIF path but also the MPU->OCP path
 114  * as well, and is necessary prior to executing a WFI.
 115  */
 116 void omap_interconnect_sync(void)
 117 {
 118         if (dram_sync && sram_sync) {
 119                 writel_relaxed(readl_relaxed(dram_sync), dram_sync);
 120                 writel_relaxed(readl_relaxed(sram_sync), sram_sync);
 121                 isb();
 122         }
 123 }
 124 
 125 static int __init omap4_sram_init(void)
 126 {
 127         struct device_node *np;
 128         struct gen_pool *sram_pool;
 129 
 130         if (!soc_is_omap44xx() && !soc_is_omap54xx())
 131                 return 0;
 132 
 133         np = of_find_compatible_node(NULL, NULL, "ti,omap4-mpu");
 134         if (!np)
 135                 pr_warn("%s:Unable to allocate sram needed to handle errata I688\n",
 136                         __func__);
 137         sram_pool = of_gen_pool_get(np, "sram", 0);
 138         if (!sram_pool)
 139                 pr_warn("%s:Unable to get sram pool needed to handle errata I688\n",
 140                         __func__);
 141         else
 142                 sram_sync = (void *)gen_pool_alloc(sram_pool, PAGE_SIZE);
 143 
 144         return 0;
 145 }
 146 omap_arch_initcall(omap4_sram_init);
 147 
 148 /* Steal one page physical memory for barrier implementation */
 149 void __init omap_barrier_reserve_memblock(void)
 150 {
 151         dram_sync_size = ALIGN(PAGE_SIZE, SZ_1M);
 152         dram_sync_paddr = arm_memblock_steal(dram_sync_size, SZ_1M);
 153 }
 154 
 155 void __init omap_barriers_init(void)
 156 {
 157         struct map_desc dram_io_desc[1];
 158 
 159         dram_io_desc[0].virtual = OMAP4_DRAM_BARRIER_VA;
 160         dram_io_desc[0].pfn = __phys_to_pfn(dram_sync_paddr);
 161         dram_io_desc[0].length = dram_sync_size;
 162         dram_io_desc[0].type = MT_MEMORY_RW_SO;
 163         iotable_init(dram_io_desc, ARRAY_SIZE(dram_io_desc));
 164         dram_sync = (void __iomem *) dram_io_desc[0].virtual;
 165 
 166         pr_info("OMAP4: Map %pa to %p for dram barrier\n",
 167                 &dram_sync_paddr, dram_sync);
 168 
 169         soc_mb = omap4_mb;
 170 }
 171 
 172 #endif
 173 
 174 void gic_dist_disable(void)
 175 {
 176         if (gic_dist_base_addr)
 177                 writel_relaxed(0x0, gic_dist_base_addr + GIC_DIST_CTRL);
 178 }
 179 
 180 void gic_dist_enable(void)
 181 {
 182         if (gic_dist_base_addr)
 183                 writel_relaxed(0x1, gic_dist_base_addr + GIC_DIST_CTRL);
 184 }
 185 
 186 bool gic_dist_disabled(void)
 187 {
 188         return !(readl_relaxed(gic_dist_base_addr + GIC_DIST_CTRL) & 0x1);
 189 }
 190 
 191 void gic_timer_retrigger(void)
 192 {
 193         u32 twd_int = readl_relaxed(twd_base + TWD_TIMER_INTSTAT);
 194         u32 gic_int = readl_relaxed(gic_dist_base_addr + GIC_DIST_PENDING_SET);
 195         u32 twd_ctrl = readl_relaxed(twd_base + TWD_TIMER_CONTROL);
 196 
 197         if (twd_int && !(gic_int & BIT(IRQ_LOCALTIMER))) {
 198                 /*
 199                  * The local timer interrupt got lost while the distributor was
 200                  * disabled.  Ack the pending interrupt, and retrigger it.
 201                  */
 202                 pr_warn("%s: lost localtimer interrupt\n", __func__);
 203                 writel_relaxed(1, twd_base + TWD_TIMER_INTSTAT);
 204                 if (!(twd_ctrl & TWD_TIMER_CONTROL_PERIODIC)) {
 205                         writel_relaxed(1, twd_base + TWD_TIMER_COUNTER);
 206                         twd_ctrl |= TWD_TIMER_CONTROL_ENABLE;
 207                         writel_relaxed(twd_ctrl, twd_base + TWD_TIMER_CONTROL);
 208                 }
 209         }
 210 }
 211 
 212 #ifdef CONFIG_CACHE_L2X0
 213 
 214 void __iomem *omap4_get_l2cache_base(void)
 215 {
 216         return l2cache_base;
 217 }
 218 
 219 void omap4_l2c310_write_sec(unsigned long val, unsigned reg)
 220 {
 221         unsigned smc_op;
 222 
 223         switch (reg) {
 224         case L2X0_CTRL:
 225                 smc_op = OMAP4_MON_L2X0_CTRL_INDEX;
 226                 break;
 227 
 228         case L2X0_AUX_CTRL:
 229                 smc_op = OMAP4_MON_L2X0_AUXCTRL_INDEX;
 230                 break;
 231 
 232         case L2X0_DEBUG_CTRL:
 233                 smc_op = OMAP4_MON_L2X0_DBG_CTRL_INDEX;
 234                 break;
 235 
 236         case L310_PREFETCH_CTRL:
 237                 smc_op = OMAP4_MON_L2X0_PREFETCH_INDEX;
 238                 break;
 239 
 240         case L310_POWER_CTRL:
 241                 pr_info_once("OMAP L2C310: ROM does not support power control setting\n");
 242                 return;
 243 
 244         default:
 245                 WARN_ONCE(1, "OMAP L2C310: ignoring write to reg 0x%x\n", reg);
 246                 return;
 247         }
 248 
 249         omap_smc1(smc_op, val);
 250 }
 251 
 252 int __init omap_l2_cache_init(void)
 253 {
 254         /* Static mapping, never released */
 255         l2cache_base = ioremap(OMAP44XX_L2CACHE_BASE, SZ_4K);
 256         if (WARN_ON(!l2cache_base))
 257                 return -ENOMEM;
 258         return 0;
 259 }
 260 #endif
 261 
 262 void __iomem *omap4_get_sar_ram_base(void)
 263 {
 264         return sar_ram_base;
 265 }
 266 
 267 /*
 268  * SAR RAM used to save and restore the HW context in low power modes.
 269  * Note that we need to initialize this very early for kexec. See
 270  * omap4_mpuss_early_init().
 271  */
 272 void __init omap4_sar_ram_init(void)
 273 {
 274         unsigned long sar_base;
 275 
 276         /*
 277          * To avoid code running on other OMAPs in
 278          * multi-omap builds
 279          */
 280         if (cpu_is_omap44xx())
 281                 sar_base = OMAP44XX_SAR_RAM_BASE;
 282         else if (soc_is_omap54xx())
 283                 sar_base = OMAP54XX_SAR_RAM_BASE;
 284         else
 285                 return;
 286 
 287         /* Static mapping, never released */
 288         sar_ram_base = ioremap(sar_base, SZ_16K);
 289         if (WARN_ON(!sar_ram_base))
 290                 return;
 291 }
 292 
 293 static const struct of_device_id intc_match[] = {
 294         { .compatible = "ti,omap4-wugen-mpu", },
 295         { .compatible = "ti,omap5-wugen-mpu", },
 296         { },
 297 };
 298 
 299 static struct device_node *intc_node;
 300 
 301 void __init omap_gic_of_init(void)
 302 {
 303         struct device_node *np;
 304 
 305         intc_node = of_find_matching_node(NULL, intc_match);
 306         if (WARN_ON(!intc_node)) {
 307                 pr_err("No WUGEN found in DT, system will misbehave.\n");
 308                 pr_err("UPDATE YOUR DEVICE TREE!\n");
 309         }
 310 
 311         /* Extract GIC distributor and TWD bases for OMAP4460 ROM Errata WA */
 312         if (!cpu_is_omap446x())
 313                 goto skip_errata_init;
 314 
 315         np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-gic");
 316         gic_dist_base_addr = of_iomap(np, 0);
 317         WARN_ON(!gic_dist_base_addr);
 318 
 319         np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-twd-timer");
 320         twd_base = of_iomap(np, 0);
 321         WARN_ON(!twd_base);
 322 
 323 skip_errata_init:
 324         irqchip_init();
 325 }