/* * TI AM33XX SRAM EMIF Driver * * Copyright (C) 2016-2017 Texas Instruments Inc. * Dave Gerlach * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * version 2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include <linux/err.h> #include <linux/genalloc.h> #include <linux/io.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/of.h> #include <linux/of_platform.h> #include <linux/platform_device.h> #include <linux/sram.h> #include <linux/ti-emif-sram.h> #include "emif.h" #define TI_EMIF_SRAM_SYMBOL_OFFSET(sym) ((unsigned long)(sym) - \ (unsigned long)&ti_emif_sram) #define EMIF_POWER_MGMT_WAIT_SELF_REFRESH_8192_CYCLES 0x00a0 struct ti_emif_data { phys_addr_t ti_emif_sram_phys; phys_addr_t ti_emif_sram_data_phys; unsigned long ti_emif_sram_virt; unsigned long ti_emif_sram_data_virt; struct gen_pool *sram_pool_code; struct gen_pool *sram_pool_data; struct ti_emif_pm_data pm_data; struct ti_emif_pm_functions pm_functions; }; static struct ti_emif_data *emif_instance; static u32 sram_suspend_address(struct ti_emif_data *emif_data, unsigned long addr) { return (emif_data->ti_emif_sram_virt + TI_EMIF_SRAM_SYMBOL_OFFSET(addr)); } static phys_addr_t sram_resume_address(struct ti_emif_data *emif_data, unsigned long addr) { return ((unsigned long)emif_data->ti_emif_sram_phys + TI_EMIF_SRAM_SYMBOL_OFFSET(addr)); } static void ti_emif_free_sram(struct ti_emif_data *emif_data) { gen_pool_free(emif_data->sram_pool_code, emif_data->ti_emif_sram_virt, ti_emif_sram_sz); gen_pool_free(emif_data->sram_pool_data, emif_data->ti_emif_sram_data_virt, sizeof(struct emif_regs_amx3)); } static int ti_emif_alloc_sram(struct device *dev, struct ti_emif_data *emif_data) { struct device_node *np = dev->of_node; int ret; emif_data->sram_pool_code = of_gen_pool_get(np, "sram", 0); if (!emif_data->sram_pool_code) { dev_err(dev, "Unable to get sram pool for ocmcram code\n"); return -ENODEV; } emif_data->ti_emif_sram_virt = gen_pool_alloc(emif_data->sram_pool_code, ti_emif_sram_sz); if (!emif_data->ti_emif_sram_virt) { dev_err(dev, "Unable to allocate code memory from ocmcram\n"); return -ENOMEM; } /* Save physical address to calculate resume offset during pm init */ emif_data->ti_emif_sram_phys = gen_pool_virt_to_phys(emif_data->sram_pool_code, emif_data->ti_emif_sram_virt); /* Get sram pool for data section and allocate space */ emif_data->sram_pool_data = of_gen_pool_get(np, "sram", 1); if (!emif_data->sram_pool_data) { dev_err(dev, "Unable to get sram pool for ocmcram data\n"); ret = -ENODEV; goto err_free_sram_code; } emif_data->ti_emif_sram_data_virt = gen_pool_alloc(emif_data->sram_pool_data, sizeof(struct emif_regs_amx3)); if (!emif_data->ti_emif_sram_data_virt) { dev_err(dev, "Unable to allocate data memory from ocmcram\n"); ret = -ENOMEM; goto err_free_sram_code; } /* Save physical address to calculate resume offset during pm init */ emif_data->ti_emif_sram_data_phys = gen_pool_virt_to_phys(emif_data->sram_pool_data, emif_data->ti_emif_sram_data_virt); /* * These functions are called during suspend path while MMU is * still on so add virtual base to offset for absolute address */ emif_data->pm_functions.save_context = sram_suspend_address(emif_data, (unsigned long)ti_emif_save_context); emif_data->pm_functions.enter_sr = sram_suspend_address(emif_data, (unsigned long)ti_emif_enter_sr); emif_data->pm_functions.abort_sr = sram_suspend_address(emif_data, (unsigned long)ti_emif_abort_sr); /* * These are called during resume path when MMU is not enabled * so physical address is used instead */ emif_data->pm_functions.restore_context = sram_resume_address(emif_data, (unsigned long)ti_emif_restore_context); emif_data->pm_functions.exit_sr = sram_resume_address(emif_data, (unsigned long)ti_emif_exit_sr); emif_data->pm_data.regs_virt = (struct emif_regs_amx3 *)emif_data->ti_emif_sram_data_virt; emif_data->pm_data.regs_phys = emif_data->ti_emif_sram_data_phys; return 0; err_free_sram_code: gen_pool_free(emif_data->sram_pool_code, emif_data->ti_emif_sram_virt, ti_emif_sram_sz); return ret; } static int ti_emif_push_sram(struct device *dev, struct ti_emif_data *emif_data) { void *copy_addr; u32 data_addr; copy_addr = sram_exec_copy(emif_data->sram_pool_code, (void *)emif_data->ti_emif_sram_virt, &ti_emif_sram, ti_emif_sram_sz); if (!copy_addr) { dev_err(dev, "Cannot copy emif code to sram\n"); return -ENODEV; } data_addr = sram_suspend_address(emif_data, (unsigned long)&ti_emif_pm_sram_data); copy_addr = sram_exec_copy(emif_data->sram_pool_code, (void *)data_addr, &emif_data->pm_data, sizeof(emif_data->pm_data)); if (!copy_addr) { dev_err(dev, "Cannot copy emif data to code sram\n"); return -ENODEV; } return 0; } /* * Due to Usage Note 3.1.2 "DDR3: JEDEC Compliance for Maximum * Self-Refresh Command Limit" found in AM335x Silicon Errata * (Document SPRZ360F Revised November 2013) we must configure * the self refresh delay timer to 0xA (8192 cycles) to avoid * generating too many refresh command from the EMIF. */ static void ti_emif_configure_sr_delay(struct ti_emif_data *emif_data) { writel(EMIF_POWER_MGMT_WAIT_SELF_REFRESH_8192_CYCLES, (emif_data->pm_data.ti_emif_base_addr_virt + EMIF_POWER_MANAGEMENT_CONTROL)); writel(EMIF_POWER_MGMT_WAIT_SELF_REFRESH_8192_CYCLES, (emif_data->pm_data.ti_emif_base_addr_virt + EMIF_POWER_MANAGEMENT_CTRL_SHDW)); } /** * ti_emif_copy_pm_function_table - copy mapping of pm funcs in sram * @sram_pool: pointer to struct gen_pool where dst resides * @dst: void * to address that table should be copied * * Returns 0 if success other error code if table is not available */ int ti_emif_copy_pm_function_table(struct gen_pool *sram_pool, void *dst) { void *copy_addr; if (!emif_instance) return -ENODEV; copy_addr = sram_exec_copy(sram_pool, dst, &emif_instance->pm_functions, sizeof(emif_instance->pm_functions)); if (!copy_addr) return -ENODEV; return 0; } EXPORT_SYMBOL_GPL(ti_emif_copy_pm_function_table); /** * ti_emif_get_mem_type - return type for memory type in use * * Returns memory type value read from EMIF or error code if fails */ int ti_emif_get_mem_type(void) { unsigned long temp; if (!emif_instance) return -ENODEV; temp = readl(emif_instance->pm_data.ti_emif_base_addr_virt + EMIF_SDRAM_CONFIG); temp = (temp & SDRAM_TYPE_MASK) >> SDRAM_TYPE_SHIFT; return temp; } EXPORT_SYMBOL_GPL(ti_emif_get_mem_type); static const struct of_device_id ti_emif_of_match[] = { { .compatible = "ti,emif-am3352", .data = (void *)EMIF_SRAM_AM33_REG_LAYOUT, }, { .compatible = "ti,emif-am4372", .data = (void *)EMIF_SRAM_AM43_REG_LAYOUT, }, {}, }; MODULE_DEVICE_TABLE(of, ti_emif_of_match); #ifdef CONFIG_PM_SLEEP static int ti_emif_resume(struct device *dev) { unsigned long tmp = __raw_readl((void *)emif_instance->ti_emif_sram_virt); /* * Check to see if what we are copying is already present in the * first byte at the destination, only copy if it is not which * indicates we have lost context and sram no longer contains * the PM code */ if (tmp != ti_emif_sram) ti_emif_push_sram(dev, emif_instance); return 0; } static int ti_emif_suspend(struct device *dev) { /* * The contents will be present in DDR hence no need to * explicitly save */ return 0; } #endif /* CONFIG_PM_SLEEP */ static int ti_emif_probe(struct platform_device *pdev) { int ret; struct resource *res; struct device *dev = &pdev->dev; const struct of_device_id *match; struct ti_emif_data *emif_data; emif_data = devm_kzalloc(dev, sizeof(*emif_data), GFP_KERNEL); if (!emif_data) return -ENOMEM; match = of_match_device(ti_emif_of_match, &pdev->dev); if (!match) return -ENODEV; emif_data->pm_data.ti_emif_sram_config = (unsigned long)match->data; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); emif_data->pm_data.ti_emif_base_addr_virt = devm_ioremap_resource(dev, res); if (IS_ERR(emif_data->pm_data.ti_emif_base_addr_virt)) { ret = PTR_ERR(emif_data->pm_data.ti_emif_base_addr_virt); return ret; } emif_data->pm_data.ti_emif_base_addr_phys = res->start; ti_emif_configure_sr_delay(emif_data); ret = ti_emif_alloc_sram(dev, emif_data); if (ret) return ret; ret = ti_emif_push_sram(dev, emif_data); if (ret) goto fail_free_sram; emif_instance = emif_data; return 0; fail_free_sram: ti_emif_free_sram(emif_data); return ret; } static int ti_emif_remove(struct platform_device *pdev) { struct ti_emif_data *emif_data = emif_instance; emif_instance = NULL; ti_emif_free_sram(emif_data); return 0; } static const struct dev_pm_ops ti_emif_pm_ops = { SET_SYSTEM_SLEEP_PM_OPS(ti_emif_suspend, ti_emif_resume) }; static struct platform_driver ti_emif_driver = { .probe = ti_emif_probe, .remove = ti_emif_remove, .driver = { .name = KBUILD_MODNAME, .of_match_table = of_match_ptr(ti_emif_of_match), .pm = &ti_emif_pm_ops, }, }; module_platform_driver(ti_emif_driver); MODULE_AUTHOR("Dave Gerlach <d-gerlach@ti.com>"); MODULE_DESCRIPTION("Texas Instruments SRAM EMIF driver"); MODULE_LICENSE("GPL v2");