diff options
Diffstat (limited to 'drivers/memory/ti-emif-pm.c')
| -rw-r--r-- | drivers/memory/ti-emif-pm.c | 324 |
1 files changed, 324 insertions, 0 deletions
diff --git a/drivers/memory/ti-emif-pm.c b/drivers/memory/ti-emif-pm.c new file mode 100644 index 000000000000..62a86c4bcd0b --- /dev/null +++ b/drivers/memory/ti-emif-pm.c @@ -0,0 +1,324 @@ +/* + * 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); + +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)) { + dev_err(dev, "could not ioremap emif mem\n"); + 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 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), + }, +}; +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"); 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