drivers/memory/ti-emif-pm.c

   1 /*
   2  * TI AM33XX SRAM EMIF Driver
   3  *
   4  * Copyright (C) 2016-2017 Texas Instruments Inc.
   5  *      Dave Gerlach
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * version 2 as published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  */
  16
  17 #include <linux/err.h>
  18 #include <linux/genalloc.h>
  19 #include <linux/io.h>
  20 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/of.h>
  23 #include <linux/of_platform.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/sram.h>
  26 #include <linux/ti-emif-sram.h>
  27
  28 #include "emif.h"
  29
  30 #define TI_EMIF_SRAM_SYMBOL_OFFSET(sym) ((unsigned long)(sym) - \
  31                                          (unsigned long)&ti_emif_sram)
  32
  33 #define EMIF_POWER_MGMT_WAIT_SELF_REFRESH_8192_CYCLES           0x00a0
  34
  35 struct ti_emif_data {
  36         phys_addr_t ti_emif_sram_phys;
  37         phys_addr_t ti_emif_sram_data_phys;
  38         unsigned long ti_emif_sram_virt;
  39         unsigned long ti_emif_sram_data_virt;
  40         struct gen_pool *sram_pool_code;
  41         struct gen_pool *sram_pool_data;
  42         struct ti_emif_pm_data pm_data;
  43         struct ti_emif_pm_functions pm_functions;
  44 };
  45
  46 static struct ti_emif_data *emif_instance;
  47
  48 static u32 sram_suspend_address(struct ti_emif_data *emif_data,
  49                                 unsigned long addr)
  50 {
  51         return (emif_data->ti_emif_sram_virt +
  52                 TI_EMIF_SRAM_SYMBOL_OFFSET(addr));
  53 }
  54
  55 static phys_addr_t sram_resume_address(struct ti_emif_data *emif_data,
  56                                        unsigned long addr)
  57 {
  58         return ((unsigned long)emif_data->ti_emif_sram_phys +
  59                 TI_EMIF_SRAM_SYMBOL_OFFSET(addr));
  60 }
  61
  62 static void ti_emif_free_sram(struct ti_emif_data *emif_data)
  63 {
  64         gen_pool_free(emif_data->sram_pool_code, emif_data->ti_emif_sram_virt,
  65                       ti_emif_sram_sz);
  66         gen_pool_free(emif_data->sram_pool_data,
  67                       emif_data->ti_emif_sram_data_virt,
  68                       sizeof(struct emif_regs_amx3));
  69 }
  70
  71 static int ti_emif_alloc_sram(struct device *dev,
  72                               struct ti_emif_data *emif_data)
  73 {
  74         struct device_node *np = dev->of_node;
  75         int ret;
  76
  77         emif_data->sram_pool_code = of_gen_pool_get(np, "sram", 0);
  78         if (!emif_data->sram_pool_code) {
  79                 dev_err(dev, "Unable to get sram pool for ocmcram code\n");
  80                 return -ENODEV;
  81         }
  82
  83         emif_data->ti_emif_sram_virt =
  84                         gen_pool_alloc(emif_data->sram_pool_code,
  85                                        ti_emif_sram_sz);
  86         if (!emif_data->ti_emif_sram_virt) {
  87                 dev_err(dev, "Unable to allocate code memory from ocmcram\n");
  88                 return -ENOMEM;
  89         }
  90
  91         /* Save physical address to calculate resume offset during pm init */
  92         emif_data->ti_emif_sram_phys =
  93                         gen_pool_virt_to_phys(emif_data->sram_pool_code,
  94                                               emif_data->ti_emif_sram_virt);
  95
  96         /* Get sram pool for data section and allocate space */
  97         emif_data->sram_pool_data = of_gen_pool_get(np, "sram", 1);
  98         if (!emif_data->sram_pool_data) {
  99                 dev_err(dev, "Unable to get sram pool for ocmcram data\n");
 100                 ret = -ENODEV;
 101                 goto err_free_sram_code;
 102         }
 103
 104         emif_data->ti_emif_sram_data_virt =
 105                                 gen_pool_alloc(emif_data->sram_pool_data,
 106                                                sizeof(struct emif_regs_amx3));
 107         if (!emif_data->ti_emif_sram_data_virt) {
 108                 dev_err(dev, "Unable to allocate data memory from ocmcram\n");
 109                 ret = -ENOMEM;
 110                 goto err_free_sram_code;
 111         }
 112
 113         /* Save physical address to calculate resume offset during pm init */
 114         emif_data->ti_emif_sram_data_phys =
 115                 gen_pool_virt_to_phys(emif_data->sram_pool_data,
 116                                       emif_data->ti_emif_sram_data_virt);
 117         /*
 118          * These functions are called during suspend path while MMU is
 119          * still on so add virtual base to offset for absolute address
 120          */
 121         emif_data->pm_functions.save_context =
 122                 sram_suspend_address(emif_data,
 123                                      (unsigned long)ti_emif_save_context);
 124         emif_data->pm_functions.enter_sr =
 125                 sram_suspend_address(emif_data,
 126                                      (unsigned long)ti_emif_enter_sr);
 127         emif_data->pm_functions.abort_sr =
 128                 sram_suspend_address(emif_data,
 129                                      (unsigned long)ti_emif_abort_sr);
 130
 131         /*
 132          * These are called during resume path when MMU is not enabled
 133          * so physical address is used instead
 134          */
 135         emif_data->pm_functions.restore_context =
 136                 sram_resume_address(emif_data,
 137                                     (unsigned long)ti_emif_restore_context);
 138         emif_data->pm_functions.exit_sr =
 139                 sram_resume_address(emif_data,
 140                                     (unsigned long)ti_emif_exit_sr);
 141
 142         emif_data->pm_data.regs_virt =
 143                 (struct emif_regs_amx3 *)emif_data->ti_emif_sram_data_virt;
 144         emif_data->pm_data.regs_phys = emif_data->ti_emif_sram_data_phys;
 145
 146         return 0;
 147
 148 err_free_sram_code:
 149         gen_pool_free(emif_data->sram_pool_code, emif_data->ti_emif_sram_virt,
 150                       ti_emif_sram_sz);
 151         return ret;
 152 }
 153
 154 static int ti_emif_push_sram(struct device *dev, struct ti_emif_data *emif_data)
 155 {
 156         void *copy_addr;
 157         u32 data_addr;
 158
 159         copy_addr = sram_exec_copy(emif_data->sram_pool_code,
 160                                    (void *)emif_data->ti_emif_sram_virt,
 161                                    &ti_emif_sram, ti_emif_sram_sz);
 162         if (!copy_addr) {
 163                 dev_err(dev, "Cannot copy emif code to sram\n");
 164                 return -ENODEV;
 165         }
 166
 167         data_addr = sram_suspend_address(emif_data,
 168                                          (unsigned long)&ti_emif_pm_sram_data);
 169         copy_addr = sram_exec_copy(emif_data->sram_pool_code,
 170                                    (void *)data_addr,
 171                                    &emif_data->pm_data,
 172                                    sizeof(emif_data->pm_data));
 173         if (!copy_addr) {
 174                 dev_err(dev, "Cannot copy emif data to code sram\n");
 175                 return -ENODEV;
 176         }
 177
 178         return 0;
 179 }
 180
 181 /*
 182  * Due to Usage Note 3.1.2 "DDR3: JEDEC Compliance for Maximum
 183  * Self-Refresh Command Limit" found in AM335x Silicon Errata
 184  * (Document SPRZ360F Revised November 2013) we must configure
 185  * the self refresh delay timer to 0xA (8192 cycles) to avoid
 186  * generating too many refresh command from the EMIF.
 187  */
 188 static void ti_emif_configure_sr_delay(struct ti_emif_data *emif_data)
 189 {
 190         writel(EMIF_POWER_MGMT_WAIT_SELF_REFRESH_8192_CYCLES,
 191                (emif_data->pm_data.ti_emif_base_addr_virt +
 192                 EMIF_POWER_MANAGEMENT_CONTROL));
 193
 194         writel(EMIF_POWER_MGMT_WAIT_SELF_REFRESH_8192_CYCLES,
 195                (emif_data->pm_data.ti_emif_base_addr_virt +
 196                 EMIF_POWER_MANAGEMENT_CTRL_SHDW));
 197 }
 198
 199 /**
 200  * ti_emif_copy_pm_function_table - copy mapping of pm funcs in sram
 201  * @sram_pool: pointer to struct gen_pool where dst resides
 202  * @dst: void * to address that table should be copied
 203  *
 204  * Returns 0 if success other error code if table is not available
 205  */
 206 int ti_emif_copy_pm_function_table(struct gen_pool *sram_pool, void *dst)
 207 {
 208         void *copy_addr;
 209
 210         if (!emif_instance)
 211                 return -ENODEV;
 212
 213         copy_addr = sram_exec_copy(sram_pool, dst,
 214                                    &emif_instance->pm_functions,
 215                                    sizeof(emif_instance->pm_functions));
 216         if (!copy_addr)
 217                 return -ENODEV;
 218
 219         return 0;
 220 }
 221 EXPORT_SYMBOL_GPL(ti_emif_copy_pm_function_table);
 222
 223 /**
 224  * ti_emif_get_mem_type - return type for memory type in use
 225  *
 226  * Returns memory type value read from EMIF or error code if fails
 227  */
 228 int ti_emif_get_mem_type(void)
 229 {
 230         unsigned long temp;
 231
 232         if (!emif_instance)
 233                 return -ENODEV;
 234
 235         temp = readl(emif_instance->pm_data.ti_emif_base_addr_virt +
 236                      EMIF_SDRAM_CONFIG);
 237
 238         temp = (temp & SDRAM_TYPE_MASK) >> SDRAM_TYPE_SHIFT;
 239         return temp;
 240 }
 241 EXPORT_SYMBOL_GPL(ti_emif_get_mem_type);
 242
 243 static const struct of_device_id ti_emif_of_match[] = {
 244         { .compatible = "ti,emif-am3352", .data =
 245                                         (void *)EMIF_SRAM_AM33_REG_LAYOUT, },
 246         { .compatible = "ti,emif-am4372", .data =
 247                                         (void *)EMIF_SRAM_AM43_REG_LAYOUT, },
 248         {},
 249 };
 250 MODULE_DEVICE_TABLE(of, ti_emif_of_match);
 251
 252 #ifdef CONFIG_PM_SLEEP
 253 static int ti_emif_resume(struct device *dev)
 254 {
 255         unsigned long tmp =
 256                         __raw_readl((void *)emif_instance->ti_emif_sram_virt);
 257
 258         /*
 259          * Check to see if what we are copying is already present in the
 260          * first byte at the destination, only copy if it is not which
 261          * indicates we have lost context and sram no longer contains
 262          * the PM code
 263          */
 264         if (tmp != ti_emif_sram)
 265                 ti_emif_push_sram(dev, emif_instance);
 266
 267         return 0;
 268 }
 269
 270 static int ti_emif_suspend(struct device *dev)
 271 {
 272         /*
 273          * The contents will be present in DDR hence no need to
 274          * explicitly save
 275          */
 276         return 0;
 277 }
 278 #endif /* CONFIG_PM_SLEEP */
 279
 280 static int ti_emif_probe(struct platform_device *pdev)
 281 {
 282         int ret;
 283         struct resource *res;
 284         struct device *dev = &pdev->dev;
 285         const struct of_device_id *match;
 286         struct ti_emif_data *emif_data;
 287
 288         emif_data = devm_kzalloc(dev, sizeof(*emif_data), GFP_KERNEL);
 289         if (!emif_data)
 290                 return -ENOMEM;
 291
 292         match = of_match_device(ti_emif_of_match, &pdev->dev);
 293         if (!match)
 294                 return -ENODEV;
 295
 296         emif_data->pm_data.ti_emif_sram_config = (unsigned long)match->data;
 297
 298         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 299         emif_data->pm_data.ti_emif_base_addr_virt = devm_ioremap_resource(dev,
 300                                                                           res);
 301         if (IS_ERR(emif_data->pm_data.ti_emif_base_addr_virt)) {
 302                 ret = PTR_ERR(emif_data->pm_data.ti_emif_base_addr_virt);
 303                 return ret;
 304         }
 305
 306         emif_data->pm_data.ti_emif_base_addr_phys = res->start;
 307
 308         ti_emif_configure_sr_delay(emif_data);
 309
 310         ret = ti_emif_alloc_sram(dev, emif_data);
 311         if (ret)
 312                 return ret;
 313
 314         ret = ti_emif_push_sram(dev, emif_data);
 315         if (ret)
 316                 goto fail_free_sram;
 317
 318         emif_instance = emif_data;
 319
 320         return 0;
 321
 322 fail_free_sram:
 323         ti_emif_free_sram(emif_data);
 324
 325         return ret;
 326 }
 327
 328 static int ti_emif_remove(struct platform_device *pdev)
 329 {
 330         struct ti_emif_data *emif_data = emif_instance;
 331
 332         emif_instance = NULL;
 333
 334         ti_emif_free_sram(emif_data);
 335
 336         return 0;
 337 }
 338
 339 static const struct dev_pm_ops ti_emif_pm_ops = {
 340         SET_SYSTEM_SLEEP_PM_OPS(ti_emif_suspend, ti_emif_resume)
 341 };
 342
 343 static struct platform_driver ti_emif_driver = {
 344         .probe = ti_emif_probe,
 345         .remove = ti_emif_remove,
 346         .driver = {
 347                 .name = KBUILD_MODNAME,
 348                 .of_match_table = of_match_ptr(ti_emif_of_match),
 349                 .pm = &ti_emif_pm_ops,
 350         },
 351 };
 352 module_platform_driver(ti_emif_driver);
 353
 354 MODULE_AUTHOR("Dave Gerlach <d-gerlach@ti.com>");
 355 MODULE_DESCRIPTION("Texas Instruments SRAM EMIF driver");
 356 MODULE_LICENSE("GPL v2");