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/*
* 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_functions.run_hw_leveling =
sram_resume_address(emif_data,
(unsigned long)ti_emif_run_hw_leveling);
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");