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"); 357