142 lines
3.0 KiB
C
142 lines
3.0 KiB
C
/*
|
|
* Board-level suspend/resume support.
|
|
*
|
|
* Copyright (C) 2014 Marvell
|
|
*
|
|
* Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
|
|
*
|
|
* 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/delay.h>
|
|
#include <linux/gpio.h>
|
|
#include <linux/init.h>
|
|
#include <linux/io.h>
|
|
#include <linux/of.h>
|
|
#include <linux/of_address.h>
|
|
#include <linux/of_gpio.h>
|
|
#include <linux/slab.h>
|
|
#include "common.h"
|
|
|
|
#define ARMADA_XP_GP_PIC_NR_GPIOS 3
|
|
|
|
static void __iomem *gpio_ctrl;
|
|
static int pic_gpios[ARMADA_XP_GP_PIC_NR_GPIOS];
|
|
static int pic_raw_gpios[ARMADA_XP_GP_PIC_NR_GPIOS];
|
|
|
|
static void mvebu_armada_xp_gp_pm_enter(void __iomem *sdram_reg, u32 srcmd)
|
|
{
|
|
u32 reg, ackcmd;
|
|
int i;
|
|
|
|
/* Put 001 as value on the GPIOs */
|
|
reg = readl(gpio_ctrl);
|
|
for (i = 0; i < ARMADA_XP_GP_PIC_NR_GPIOS; i++)
|
|
reg &= ~BIT(pic_raw_gpios[i]);
|
|
reg |= BIT(pic_raw_gpios[0]);
|
|
writel(reg, gpio_ctrl);
|
|
|
|
/* Prepare writing 111 to the GPIOs */
|
|
ackcmd = readl(gpio_ctrl);
|
|
for (i = 0; i < ARMADA_XP_GP_PIC_NR_GPIOS; i++)
|
|
ackcmd |= BIT(pic_raw_gpios[i]);
|
|
|
|
/*
|
|
* Wait a while, the PIC needs quite a bit of time between the
|
|
* two GPIO commands.
|
|
*/
|
|
mdelay(3000);
|
|
|
|
asm volatile (
|
|
/* Align to a cache line */
|
|
".balign 32\n\t"
|
|
|
|
/* Enter self refresh */
|
|
"str %[srcmd], [%[sdram_reg]]\n\t"
|
|
|
|
/*
|
|
* Wait 100 cycles for DDR to enter self refresh, by
|
|
* doing 50 times two instructions.
|
|
*/
|
|
"mov r1, #50\n\t"
|
|
"1: subs r1, r1, #1\n\t"
|
|
"bne 1b\n\t"
|
|
|
|
/* Issue the command ACK */
|
|
"str %[ackcmd], [%[gpio_ctrl]]\n\t"
|
|
|
|
/* Trap the processor */
|
|
"b .\n\t"
|
|
: : [srcmd] "r" (srcmd), [sdram_reg] "r" (sdram_reg),
|
|
[ackcmd] "r" (ackcmd), [gpio_ctrl] "r" (gpio_ctrl) : "r1");
|
|
}
|
|
|
|
static int mvebu_armada_xp_gp_pm_init(void)
|
|
{
|
|
struct device_node *np;
|
|
struct device_node *gpio_ctrl_np;
|
|
int ret = 0, i;
|
|
|
|
if (!of_machine_is_compatible("marvell,axp-gp"))
|
|
return -ENODEV;
|
|
|
|
np = of_find_node_by_name(NULL, "pm_pic");
|
|
if (!np)
|
|
return -ENODEV;
|
|
|
|
for (i = 0; i < ARMADA_XP_GP_PIC_NR_GPIOS; i++) {
|
|
char *name;
|
|
struct of_phandle_args args;
|
|
|
|
pic_gpios[i] = of_get_named_gpio(np, "ctrl-gpios", i);
|
|
if (pic_gpios[i] < 0) {
|
|
ret = -ENODEV;
|
|
goto out;
|
|
}
|
|
|
|
name = kasprintf(GFP_KERNEL, "pic-pin%d", i);
|
|
if (!name) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
ret = gpio_request(pic_gpios[i], name);
|
|
if (ret < 0) {
|
|
kfree(name);
|
|
goto out;
|
|
}
|
|
|
|
ret = gpio_direction_output(pic_gpios[i], 0);
|
|
if (ret < 0) {
|
|
gpio_free(pic_gpios[i]);
|
|
kfree(name);
|
|
goto out;
|
|
}
|
|
|
|
ret = of_parse_phandle_with_fixed_args(np, "ctrl-gpios", 2,
|
|
i, &args);
|
|
if (ret < 0) {
|
|
gpio_free(pic_gpios[i]);
|
|
kfree(name);
|
|
goto out;
|
|
}
|
|
|
|
gpio_ctrl_np = args.np;
|
|
pic_raw_gpios[i] = args.args[0];
|
|
}
|
|
|
|
gpio_ctrl = of_iomap(gpio_ctrl_np, 0);
|
|
if (!gpio_ctrl)
|
|
return -ENOMEM;
|
|
|
|
mvebu_pm_init(mvebu_armada_xp_gp_pm_enter);
|
|
|
|
out:
|
|
of_node_put(np);
|
|
return ret;
|
|
}
|
|
|
|
late_initcall(mvebu_armada_xp_gp_pm_init);
|