LXR linux/drivers/memory/ti-emif-pm.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * TI AM33XX SRAM EMIF Driver
   4 *
   5 * Copyright (C) 2016-2017 Texas Instruments Inc.
   6 *      Dave Gerlach
   7 */
   8
   9#include <linux/err.h>
  10#include <linux/genalloc.h>
  11#include <linux/io.h>
  12#include <linux/kernel.h>
  13#include <linux/module.h>
  14#include <linux/of.h>
  15#include <linux/of_platform.h>
  16#include <linux/platform_device.h>
  17#include <linux/sram.h>
  18#include <linux/ti-emif-sram.h>
  19
  20#include "emif.h"
  21
  22#define TI_EMIF_SRAM_SYMBOL_OFFSET(sym) ((unsigned long)(sym) - \
  23                                         (unsigned long)&ti_emif_sram)
  24
  25#define EMIF_POWER_MGMT_WAIT_SELF_REFRESH_8192_CYCLES           0x00a0
  26
  27struct ti_emif_data {
  28        phys_addr_t ti_emif_sram_phys;
  29        phys_addr_t ti_emif_sram_data_phys;
  30        unsigned long ti_emif_sram_virt;
  31        unsigned long ti_emif_sram_data_virt;
  32        struct gen_pool *sram_pool_code;
  33        struct gen_pool *sram_pool_data;
  34        struct ti_emif_pm_data pm_data;
  35        struct ti_emif_pm_functions pm_functions;
  36};
  37
  38static struct ti_emif_data *emif_instance;
  39
  40static u32 sram_suspend_address(struct ti_emif_data *emif_data,
  41                                unsigned long addr)
  42{
  43        return (emif_data->ti_emif_sram_virt +
  44                TI_EMIF_SRAM_SYMBOL_OFFSET(addr));
  45}
  46
  47static phys_addr_t sram_resume_address(struct ti_emif_data *emif_data,
  48                                       unsigned long addr)
  49{
  50        return ((unsigned long)emif_data->ti_emif_sram_phys +
  51                TI_EMIF_SRAM_SYMBOL_OFFSET(addr));
  52}
  53
  54static void ti_emif_free_sram(struct ti_emif_data *emif_data)
  55{
  56        gen_pool_free(emif_data->sram_pool_code, emif_data->ti_emif_sram_virt,
  57                      ti_emif_sram_sz);
  58        gen_pool_free(emif_data->sram_pool_data,
  59                      emif_data->ti_emif_sram_data_virt,
  60                      sizeof(struct emif_regs_amx3));
  61}
  62
  63static int ti_emif_alloc_sram(struct device *dev,
  64                              struct ti_emif_data *emif_data)
  65{
  66        struct device_node *np = dev->of_node;
  67        int ret;
  68
  69        emif_data->sram_pool_code = of_gen_pool_get(np, "sram", 0);
  70        if (!emif_data->sram_pool_code) {
  71                dev_err(dev, "Unable to get sram pool for ocmcram code\n");
  72                return -ENODEV;
  73        }
  74
  75        emif_data->ti_emif_sram_virt =
  76                        gen_pool_alloc(emif_data->sram_pool_code,
  77                                       ti_emif_sram_sz);
  78        if (!emif_data->ti_emif_sram_virt) {
  79                dev_err(dev, "Unable to allocate code memory from ocmcram\n");
  80                return -ENOMEM;
  81        }
  82
  83        /* Save physical address to calculate resume offset during pm init */
  84        emif_data->ti_emif_sram_phys =
  85                        gen_pool_virt_to_phys(emif_data->sram_pool_code,
  86                                              emif_data->ti_emif_sram_virt);
  87
  88        /* Get sram pool for data section and allocate space */
  89        emif_data->sram_pool_data = of_gen_pool_get(np, "sram", 1);
  90        if (!emif_data->sram_pool_data) {
  91                dev_err(dev, "Unable to get sram pool for ocmcram data\n");
  92                ret = -ENODEV;
  93                goto err_free_sram_code;
  94        }
  95
  96        emif_data->ti_emif_sram_data_virt =
  97                                gen_pool_alloc(emif_data->sram_pool_data,
  98                                               sizeof(struct emif_regs_amx3));
  99        if (!emif_data->ti_emif_sram_data_virt) {
 100                dev_err(dev, "Unable to allocate data memory from ocmcram\n");
 101                ret = -ENOMEM;
 102                goto err_free_sram_code;
 103        }
 104
 105        /* Save physical address to calculate resume offset during pm init */
 106        emif_data->ti_emif_sram_data_phys =
 107                gen_pool_virt_to_phys(emif_data->sram_pool_data,
 108                                      emif_data->ti_emif_sram_data_virt);
 109        /*
 110         * These functions are called during suspend path while MMU is
 111         * still on so add virtual base to offset for absolute address
 112         */
 113        emif_data->pm_functions.save_context =
 114                sram_suspend_address(emif_data,
 115                                     (unsigned long)ti_emif_save_context);
 116        emif_data->pm_functions.enter_sr =
 117                sram_suspend_address(emif_data,
 118                                     (unsigned long)ti_emif_enter_sr);
 119        emif_data->pm_functions.abort_sr =
 120                sram_suspend_address(emif_data,
 121                                     (unsigned long)ti_emif_abort_sr);
 122
 123        /*
 124         * These are called during resume path when MMU is not enabled
 125         * so physical address is used instead
 126         */
 127        emif_data->pm_functions.restore_context =
 128                sram_resume_address(emif_data,
 129                                    (unsigned long)ti_emif_restore_context);
 130        emif_data->pm_functions.exit_sr =
 131                sram_resume_address(emif_data,
 132                                    (unsigned long)ti_emif_exit_sr);
 133        emif_data->pm_functions.run_hw_leveling =
 134                sram_resume_address(emif_data,
 135                                    (unsigned long)ti_emif_run_hw_leveling);
 136
 137        emif_data->pm_data.regs_virt =
 138                (struct emif_regs_amx3 *)emif_data->ti_emif_sram_data_virt;
 139        emif_data->pm_data.regs_phys = emif_data->ti_emif_sram_data_phys;
 140
 141        return 0;
 142
 143err_free_sram_code:
 144        gen_pool_free(emif_data->sram_pool_code, emif_data->ti_emif_sram_virt,
 145                      ti_emif_sram_sz);
 146        return ret;
 147}
 148
 149static int ti_emif_push_sram(struct device *dev, struct ti_emif_data *emif_data)
 150{
 151        void *copy_addr;
 152        u32 data_addr;
 153
 154        copy_addr = sram_exec_copy(emif_data->sram_pool_code,
 155                                   (void *)emif_data->ti_emif_sram_virt,
 156                                   &ti_emif_sram, ti_emif_sram_sz);
 157        if (!copy_addr) {
 158                dev_err(dev, "Cannot copy emif code to sram\n");
 159                return -ENODEV;
 160        }
 161
 162        data_addr = sram_suspend_address(emif_data,
 163                                         (unsigned long)&ti_emif_pm_sram_data);
 164        copy_addr = sram_exec_copy(emif_data->sram_pool_code,
 165                                   (void *)data_addr,
 166                                   &emif_data->pm_data,
 167                                   sizeof(emif_data->pm_data));
 168        if (!copy_addr) {
 169                dev_err(dev, "Cannot copy emif data to code sram\n");
 170                return -ENODEV;
 171        }
 172
 173        return 0;
 174}
 175
 176/*
 177 * Due to Usage Note 3.1.2 "DDR3: JEDEC Compliance for Maximum
 178 * Self-Refresh Command Limit" found in AM335x Silicon Errata
 179 * (Document SPRZ360F Revised November 2013) we must configure
 180 * the self refresh delay timer to 0xA (8192 cycles) to avoid
 181 * generating too many refresh command from the EMIF.
 182 */
 183static void ti_emif_configure_sr_delay(struct ti_emif_data *emif_data)
 184{
 185        writel(EMIF_POWER_MGMT_WAIT_SELF_REFRESH_8192_CYCLES,
 186               (emif_data->pm_data.ti_emif_base_addr_virt +
 187                EMIF_POWER_MANAGEMENT_CONTROL));
 188
 189        writel(EMIF_POWER_MGMT_WAIT_SELF_REFRESH_8192_CYCLES,
 190               (emif_data->pm_data.ti_emif_base_addr_virt +
 191                EMIF_POWER_MANAGEMENT_CTRL_SHDW));
 192}
 193
 194/**
 195 * ti_emif_copy_pm_function_table - copy mapping of pm funcs in sram
 196 * @sram_pool: pointer to struct gen_pool where dst resides
 197 * @dst: void * to address that table should be copied
 198 *
 199 * Returns 0 if success other error code if table is not available
 200 */
 201int ti_emif_copy_pm_function_table(struct gen_pool *sram_pool, void *dst)
 202{
 203        void *copy_addr;
 204
 205        if (!emif_instance)
 206                return -ENODEV;
 207
 208        copy_addr = sram_exec_copy(sram_pool, dst,
 209                                   &emif_instance->pm_functions,
 210                                   sizeof(emif_instance->pm_functions));
 211        if (!copy_addr)
 212                return -ENODEV;
 213
 214        return 0;
 215}
 216EXPORT_SYMBOL_GPL(ti_emif_copy_pm_function_table);
 217
 218/**
 219 * ti_emif_get_mem_type - return type for memory type in use
 220 *
 221 * Returns memory type value read from EMIF or error code if fails
 222 */
 223int ti_emif_get_mem_type(void)
 224{
 225        unsigned long temp;
 226
 227        if (!emif_instance)
 228                return -ENODEV;
 229
 230        temp = readl(emif_instance->pm_data.ti_emif_base_addr_virt +
 231                     EMIF_SDRAM_CONFIG);
 232
 233        temp = (temp & SDRAM_TYPE_MASK) >> SDRAM_TYPE_SHIFT;
 234        return temp;
 235}
 236EXPORT_SYMBOL_GPL(ti_emif_get_mem_type);
 237
 238static const struct of_device_id ti_emif_of_match[] = {
 239        { .compatible = "ti,emif-am3352", .data =
 240                                        (void *)EMIF_SRAM_AM33_REG_LAYOUT, },
 241        { .compatible = "ti,emif-am4372", .data =
 242                                        (void *)EMIF_SRAM_AM43_REG_LAYOUT, },
 243        {},
 244};
 245MODULE_DEVICE_TABLE(of, ti_emif_of_match);
 246
 247#ifdef CONFIG_PM_SLEEP
 248static int ti_emif_resume(struct device *dev)
 249{
 250        unsigned long tmp =
 251                        __raw_readl((void __iomem *)emif_instance->ti_emif_sram_virt);
 252
 253        /*
 254         * Check to see if what we are copying is already present in the
 255         * first byte at the destination, only copy if it is not which
 256         * indicates we have lost context and sram no longer contains
 257         * the PM code
 258         */
 259        if (tmp != ti_emif_sram)
 260                ti_emif_push_sram(dev, emif_instance);
 261
 262        return 0;
 263}
 264
 265static int ti_emif_suspend(struct device *dev)
 266{
 267        /*
 268         * The contents will be present in DDR hence no need to
 269         * explicitly save
 270         */
 271        return 0;
 272}
 273#endif /* CONFIG_PM_SLEEP */
 274
 275static int ti_emif_probe(struct platform_device *pdev)
 276{
 277        int ret;
 278        struct resource *res;
 279        struct device *dev = &pdev->dev;
 280        const struct of_device_id *match;
 281        struct ti_emif_data *emif_data;
 282
 283        emif_data = devm_kzalloc(dev, sizeof(*emif_data), GFP_KERNEL);
 284        if (!emif_data)
 285                return -ENOMEM;
 286
 287        match = of_match_device(ti_emif_of_match, &pdev->dev);
 288        if (!match)
 289                return -ENODEV;
 290
 291        emif_data->pm_data.ti_emif_sram_config = (unsigned long)match->data;
 292
 293        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 294        emif_data->pm_data.ti_emif_base_addr_virt = devm_ioremap_resource(dev,
 295                                                                          res);
 296        if (IS_ERR(emif_data->pm_data.ti_emif_base_addr_virt)) {
 297                ret = PTR_ERR(emif_data->pm_data.ti_emif_base_addr_virt);
 298                return ret;
 299        }
 300
 301        emif_data->pm_data.ti_emif_base_addr_phys = res->start;
 302
 303        ti_emif_configure_sr_delay(emif_data);
 304
 305        ret = ti_emif_alloc_sram(dev, emif_data);
 306        if (ret)
 307                return ret;
 308
 309        ret = ti_emif_push_sram(dev, emif_data);
 310        if (ret)
 311                goto fail_free_sram;
 312
 313        emif_instance = emif_data;
 314
 315        return 0;
 316
 317fail_free_sram:
 318        ti_emif_free_sram(emif_data);
 319
 320        return ret;
 321}
 322
 323static int ti_emif_remove(struct platform_device *pdev)
 324{
 325        struct ti_emif_data *emif_data = emif_instance;
 326
 327        emif_instance = NULL;
 328
 329        ti_emif_free_sram(emif_data);
 330
 331        return 0;
 332}
 333
 334static const struct dev_pm_ops ti_emif_pm_ops = {
 335        SET_SYSTEM_SLEEP_PM_OPS(ti_emif_suspend, ti_emif_resume)
 336};
 337
 338static struct platform_driver ti_emif_driver = {
 339        .probe = ti_emif_probe,
 340        .remove = ti_emif_remove,
 341        .driver = {
 342                .name = KBUILD_MODNAME,
 343                .of_match_table = ti_emif_of_match,
 344                .pm = &ti_emif_pm_ops,
 345        },
 346};
 347module_platform_driver(ti_emif_driver);
 348
 349MODULE_AUTHOR("Dave Gerlach <d-gerlach@ti.com>");
 350MODULE_DESCRIPTION("Texas Instruments SRAM EMIF driver");
 351MODULE_LICENSE("GPL v2");
 352