root/drivers/memory/ti-emif-pm.c

DEFINITIONS

1. sram_suspend_address
2. sram_resume_address
3. ti_emif_free_sram
4. ti_emif_alloc_sram
5. ti_emif_push_sram
6. ti_emif_configure_sr_delay
7. ti_emif_copy_pm_function_table
8. ti_emif_get_mem_type
9. ti_emif_resume
10. ti_emif_suspend
11. ti_emif_probe
12. ti_emif_remove

   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 
  27 struct 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 
  38 static struct ti_emif_data *emif_instance;
  39 
  40 static 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 
  47 static 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 
  54 static 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 
  63 static 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 
 143 err_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 
 149 static 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  */
 183 static 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  */
 201 int 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 }
 216 EXPORT_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  */
 223 int 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 }
 236 EXPORT_SYMBOL_GPL(ti_emif_get_mem_type);
 237 
 238 static 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 };
 245 MODULE_DEVICE_TABLE(of, ti_emif_of_match);
 246 
 247 #ifdef CONFIG_PM_SLEEP
 248 static int ti_emif_resume(struct device *dev)
 249 {
 250         unsigned long tmp =
 251                         __raw_readl((void *)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 
 265 static 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 
 275 static 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 
 317 fail_free_sram:
 318         ti_emif_free_sram(emif_data);
 319 
 320         return ret;
 321 }
 322 
 323 static 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 
 334 static const struct dev_pm_ops ti_emif_pm_ops = {
 335         SET_SYSTEM_SLEEP_PM_OPS(ti_emif_suspend, ti_emif_resume)
 336 };
 337 
 338 static 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 = of_match_ptr(ti_emif_of_match),
 344                 .pm = &ti_emif_pm_ops,
 345         },
 346 };
 347 module_platform_driver(ti_emif_driver);
 348 
 349 MODULE_AUTHOR("Dave Gerlach <d-gerlach@ti.com>");
 350 MODULE_DESCRIPTION("Texas Instruments SRAM EMIF driver");
 351 MODULE_LICENSE("GPL v2");