263 lines
6.9 KiB
C
263 lines
6.9 KiB
C
/*
|
|
* Atmel AT91 SAM9 & SAMA5 SoCs reset code
|
|
*
|
|
* Copyright (C) 2007 Atmel Corporation.
|
|
* Copyright (C) BitBox Ltd 2010
|
|
* Copyright (C) 2011 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcosoft.com>
|
|
* Copyright (C) 2014 Free Electrons
|
|
*
|
|
* This file is licensed under the terms of the GNU General Public
|
|
* License version 2. This program is licensed "as is" without any
|
|
* warranty of any kind, whether express or implied.
|
|
*/
|
|
|
|
#include <linux/clk.h>
|
|
#include <linux/io.h>
|
|
#include <linux/module.h>
|
|
#include <linux/of_address.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/reboot.h>
|
|
|
|
#include <soc/at91/at91sam9_ddrsdr.h>
|
|
#include <soc/at91/at91sam9_sdramc.h>
|
|
|
|
#define AT91_RSTC_CR 0x00 /* Reset Controller Control Register */
|
|
#define AT91_RSTC_PROCRST BIT(0) /* Processor Reset */
|
|
#define AT91_RSTC_PERRST BIT(2) /* Peripheral Reset */
|
|
#define AT91_RSTC_EXTRST BIT(3) /* External Reset */
|
|
#define AT91_RSTC_KEY (0xa5 << 24) /* KEY Password */
|
|
|
|
#define AT91_RSTC_SR 0x04 /* Reset Controller Status Register */
|
|
#define AT91_RSTC_URSTS BIT(0) /* User Reset Status */
|
|
#define AT91_RSTC_RSTTYP GENMASK(10, 8) /* Reset Type */
|
|
#define AT91_RSTC_NRSTL BIT(16) /* NRST Pin Level */
|
|
#define AT91_RSTC_SRCMP BIT(17) /* Software Reset Command in Progress */
|
|
|
|
#define AT91_RSTC_MR 0x08 /* Reset Controller Mode Register */
|
|
#define AT91_RSTC_URSTEN BIT(0) /* User Reset Enable */
|
|
#define AT91_RSTC_URSTIEN BIT(4) /* User Reset Interrupt Enable */
|
|
#define AT91_RSTC_ERSTL GENMASK(11, 8) /* External Reset Length */
|
|
|
|
enum reset_type {
|
|
RESET_TYPE_GENERAL = 0,
|
|
RESET_TYPE_WAKEUP = 1,
|
|
RESET_TYPE_WATCHDOG = 2,
|
|
RESET_TYPE_SOFTWARE = 3,
|
|
RESET_TYPE_USER = 4,
|
|
};
|
|
|
|
static void __iomem *at91_ramc_base[2], *at91_rstc_base;
|
|
static struct clk *sclk;
|
|
|
|
/*
|
|
* unless the SDRAM is cleanly shutdown before we hit the
|
|
* reset register it can be left driving the data bus and
|
|
* killing the chance of a subsequent boot from NAND
|
|
*/
|
|
static int at91sam9260_restart(struct notifier_block *this, unsigned long mode,
|
|
void *cmd)
|
|
{
|
|
asm volatile(
|
|
/* Align to cache lines */
|
|
".balign 32\n\t"
|
|
|
|
/* Disable SDRAM accesses */
|
|
"str %2, [%0, #" __stringify(AT91_SDRAMC_TR) "]\n\t"
|
|
|
|
/* Power down SDRAM */
|
|
"str %3, [%0, #" __stringify(AT91_SDRAMC_LPR) "]\n\t"
|
|
|
|
/* Reset CPU */
|
|
"str %4, [%1, #" __stringify(AT91_RSTC_CR) "]\n\t"
|
|
|
|
"b .\n\t"
|
|
:
|
|
: "r" (at91_ramc_base[0]),
|
|
"r" (at91_rstc_base),
|
|
"r" (1),
|
|
"r" cpu_to_le32(AT91_SDRAMC_LPCB_POWER_DOWN),
|
|
"r" cpu_to_le32(AT91_RSTC_KEY | AT91_RSTC_PERRST | AT91_RSTC_PROCRST));
|
|
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
static int at91sam9g45_restart(struct notifier_block *this, unsigned long mode,
|
|
void *cmd)
|
|
{
|
|
asm volatile(
|
|
/*
|
|
* Test wether we have a second RAM controller to care
|
|
* about.
|
|
*
|
|
* First, test that we can dereference the virtual address.
|
|
*/
|
|
"cmp %1, #0\n\t"
|
|
"beq 1f\n\t"
|
|
|
|
/* Then, test that the RAM controller is enabled */
|
|
"ldr r0, [%1]\n\t"
|
|
"cmp r0, #0\n\t"
|
|
|
|
/* Align to cache lines */
|
|
".balign 32\n\t"
|
|
|
|
/* Disable SDRAM0 accesses */
|
|
"1: str %3, [%0, #" __stringify(AT91_DDRSDRC_RTR) "]\n\t"
|
|
/* Power down SDRAM0 */
|
|
" str %4, [%0, #" __stringify(AT91_DDRSDRC_LPR) "]\n\t"
|
|
/* Disable SDRAM1 accesses */
|
|
" strne %3, [%1, #" __stringify(AT91_DDRSDRC_RTR) "]\n\t"
|
|
/* Power down SDRAM1 */
|
|
" strne %4, [%1, #" __stringify(AT91_DDRSDRC_LPR) "]\n\t"
|
|
/* Reset CPU */
|
|
" str %5, [%2, #" __stringify(AT91_RSTC_CR) "]\n\t"
|
|
|
|
" b .\n\t"
|
|
:
|
|
: "r" (at91_ramc_base[0]),
|
|
"r" (at91_ramc_base[1]),
|
|
"r" (at91_rstc_base),
|
|
"r" (1),
|
|
"r" cpu_to_le32(AT91_DDRSDRC_LPCB_POWER_DOWN),
|
|
"r" cpu_to_le32(AT91_RSTC_KEY | AT91_RSTC_PERRST | AT91_RSTC_PROCRST)
|
|
: "r0");
|
|
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
static int sama5d3_restart(struct notifier_block *this, unsigned long mode,
|
|
void *cmd)
|
|
{
|
|
writel(cpu_to_le32(AT91_RSTC_KEY | AT91_RSTC_PERRST | AT91_RSTC_PROCRST),
|
|
at91_rstc_base);
|
|
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
static int samx7_restart(struct notifier_block *this, unsigned long mode,
|
|
void *cmd)
|
|
{
|
|
writel(cpu_to_le32(AT91_RSTC_KEY | AT91_RSTC_PROCRST),
|
|
at91_rstc_base);
|
|
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
static void __init at91_reset_status(struct platform_device *pdev)
|
|
{
|
|
const char *reason;
|
|
u32 reg = readl(at91_rstc_base + AT91_RSTC_SR);
|
|
|
|
switch ((reg & AT91_RSTC_RSTTYP) >> 8) {
|
|
case RESET_TYPE_GENERAL:
|
|
reason = "general reset";
|
|
break;
|
|
case RESET_TYPE_WAKEUP:
|
|
reason = "wakeup";
|
|
break;
|
|
case RESET_TYPE_WATCHDOG:
|
|
reason = "watchdog reset";
|
|
break;
|
|
case RESET_TYPE_SOFTWARE:
|
|
reason = "software reset";
|
|
break;
|
|
case RESET_TYPE_USER:
|
|
reason = "user reset";
|
|
break;
|
|
default:
|
|
reason = "unknown reset";
|
|
break;
|
|
}
|
|
|
|
dev_info(&pdev->dev, "Starting after %s\n", reason);
|
|
}
|
|
|
|
static const struct of_device_id at91_ramc_of_match[] = {
|
|
{ .compatible = "atmel,at91sam9260-sdramc", },
|
|
{ .compatible = "atmel,at91sam9g45-ddramc", },
|
|
{ /* sentinel */ }
|
|
};
|
|
|
|
static const struct of_device_id at91_reset_of_match[] = {
|
|
{ .compatible = "atmel,at91sam9260-rstc", .data = at91sam9260_restart },
|
|
{ .compatible = "atmel,at91sam9g45-rstc", .data = at91sam9g45_restart },
|
|
{ .compatible = "atmel,sama5d3-rstc", .data = sama5d3_restart },
|
|
{ .compatible = "atmel,samx7-rstc", .data = samx7_restart },
|
|
{ /* sentinel */ }
|
|
};
|
|
MODULE_DEVICE_TABLE(of, at91_reset_of_match);
|
|
|
|
static struct notifier_block at91_restart_nb = {
|
|
.priority = 192,
|
|
};
|
|
|
|
static int __init at91_reset_probe(struct platform_device *pdev)
|
|
{
|
|
const struct of_device_id *match;
|
|
struct device_node *np;
|
|
int ret, idx = 0;
|
|
|
|
at91_rstc_base = of_iomap(pdev->dev.of_node, 0);
|
|
if (!at91_rstc_base) {
|
|
dev_err(&pdev->dev, "Could not map reset controller address\n");
|
|
return -ENODEV;
|
|
}
|
|
|
|
if (!of_device_is_compatible(pdev->dev.of_node, "atmel,sama5d3-rstc")) {
|
|
/* we need to shutdown the ddr controller, so get ramc base */
|
|
for_each_matching_node(np, at91_ramc_of_match) {
|
|
at91_ramc_base[idx] = of_iomap(np, 0);
|
|
if (!at91_ramc_base[idx]) {
|
|
dev_err(&pdev->dev, "Could not map ram controller address\n");
|
|
of_node_put(np);
|
|
return -ENODEV;
|
|
}
|
|
idx++;
|
|
}
|
|
}
|
|
|
|
match = of_match_node(at91_reset_of_match, pdev->dev.of_node);
|
|
at91_restart_nb.notifier_call = match->data;
|
|
|
|
sclk = devm_clk_get(&pdev->dev, NULL);
|
|
if (IS_ERR(sclk))
|
|
return PTR_ERR(sclk);
|
|
|
|
ret = clk_prepare_enable(sclk);
|
|
if (ret) {
|
|
dev_err(&pdev->dev, "Could not enable slow clock\n");
|
|
return ret;
|
|
}
|
|
|
|
ret = register_restart_handler(&at91_restart_nb);
|
|
if (ret) {
|
|
clk_disable_unprepare(sclk);
|
|
return ret;
|
|
}
|
|
|
|
at91_reset_status(pdev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __exit at91_reset_remove(struct platform_device *pdev)
|
|
{
|
|
unregister_restart_handler(&at91_restart_nb);
|
|
clk_disable_unprepare(sclk);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct platform_driver at91_reset_driver = {
|
|
.remove = __exit_p(at91_reset_remove),
|
|
.driver = {
|
|
.name = "at91-reset",
|
|
.of_match_table = at91_reset_of_match,
|
|
},
|
|
};
|
|
module_platform_driver_probe(at91_reset_driver, at91_reset_probe);
|
|
|
|
MODULE_AUTHOR("Atmel Corporation");
|
|
MODULE_DESCRIPTION("Reset driver for Atmel SoCs");
|
|
MODULE_LICENSE("GPL v2");
|