mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
157 lines
3.5 KiB
157 lines
3.5 KiB
/* |
|
* Board-level suspend/resume support. |
|
* |
|
* Copyright (C) 2014-2015 Marvell |
|
* |
|
* Thomas Petazzoni <[email protected]> |
|
* |
|
* 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_PIC_NR_GPIOS 3 |
|
|
|
static void __iomem *gpio_ctrl; |
|
static int pic_gpios[ARMADA_PIC_NR_GPIOS]; |
|
static int pic_raw_gpios[ARMADA_PIC_NR_GPIOS]; |
|
|
|
static void mvebu_armada_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_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_PIC_NR_GPIOS; i++) |
|
ackcmd |= BIT(pic_raw_gpios[i]); |
|
|
|
srcmd = cpu_to_le32(srcmd); |
|
ackcmd = cpu_to_le32(ackcmd); |
|
|
|
/* |
|
* 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 __init mvebu_armada_pm_init(void) |
|
{ |
|
struct device_node *np; |
|
struct device_node *gpio_ctrl_np = NULL; |
|
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_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; |
|
} |
|
|
|
if (gpio_ctrl_np) |
|
of_node_put(gpio_ctrl_np); |
|
gpio_ctrl_np = args.np; |
|
pic_raw_gpios[i] = args.args[0]; |
|
} |
|
|
|
gpio_ctrl = of_iomap(gpio_ctrl_np, 0); |
|
if (!gpio_ctrl) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
mvebu_pm_suspend_init(mvebu_armada_pm_enter); |
|
|
|
out: |
|
of_node_put(np); |
|
of_node_put(gpio_ctrl_np); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Registering the mvebu_board_pm_enter callback must be done before |
|
* the platform_suspend_ops will be registered. In the same time we |
|
* also need to have the gpio devices registered. That's why we use a |
|
* device_initcall_sync which is called after all the device_initcall |
|
* (used by the gpio device) but before the late_initcall (used to |
|
* register the platform_suspend_ops) |
|
*/ |
|
device_initcall_sync(mvebu_armada_pm_init);
|
|
|