diff options
Diffstat (limited to 'arch/arm/mach-mvebu/pm-board.c')
-rw-r--r-- | arch/arm/mach-mvebu/pm-board.c | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/arch/arm/mach-mvebu/pm-board.c b/arch/arm/mach-mvebu/pm-board.c new file mode 100644 index 000000000..db17121d7 --- /dev/null +++ b/arch/arm/mach-mvebu/pm-board.c @@ -0,0 +1,152 @@ +/* + * Board-level suspend/resume support. + * + * Copyright (C) 2014-2015 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_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; + 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; + } + + 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_suspend_init(mvebu_armada_pm_enter); + +out: + of_node_put(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); |