153 lines
3.4 KiB
C
153 lines
3.4 KiB
C
/*
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* Board-level suspend/resume support.
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*
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* Copyright (C) 2014-2015 Marvell
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*
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* Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
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*
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* This file is licensed under the terms of the GNU General Public
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* License version 2. This program is licensed "as is" without any
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* warranty of any kind, whether express or implied.
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*/
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#include <linux/delay.h>
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#include <linux/gpio.h>
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#include <linux/init.h>
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#include <linux/io.h>
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#include <linux/of.h>
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#include <linux/of_address.h>
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#include <linux/of_gpio.h>
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#include <linux/slab.h>
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#include "common.h"
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#define ARMADA_PIC_NR_GPIOS 3
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static void __iomem *gpio_ctrl;
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static int pic_gpios[ARMADA_PIC_NR_GPIOS];
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static int pic_raw_gpios[ARMADA_PIC_NR_GPIOS];
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static void mvebu_armada_pm_enter(void __iomem *sdram_reg, u32 srcmd)
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{
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u32 reg, ackcmd;
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int i;
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/* Put 001 as value on the GPIOs */
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reg = readl(gpio_ctrl);
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for (i = 0; i < ARMADA_PIC_NR_GPIOS; i++)
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reg &= ~BIT(pic_raw_gpios[i]);
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reg |= BIT(pic_raw_gpios[0]);
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writel(reg, gpio_ctrl);
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/* Prepare writing 111 to the GPIOs */
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ackcmd = readl(gpio_ctrl);
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for (i = 0; i < ARMADA_PIC_NR_GPIOS; i++)
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ackcmd |= BIT(pic_raw_gpios[i]);
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srcmd = cpu_to_le32(srcmd);
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ackcmd = cpu_to_le32(ackcmd);
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/*
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* Wait a while, the PIC needs quite a bit of time between the
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* two GPIO commands.
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*/
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mdelay(3000);
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asm volatile (
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/* Align to a cache line */
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".balign 32\n\t"
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/* Enter self refresh */
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"str %[srcmd], [%[sdram_reg]]\n\t"
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/*
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* Wait 100 cycles for DDR to enter self refresh, by
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* doing 50 times two instructions.
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*/
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"mov r1, #50\n\t"
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"1: subs r1, r1, #1\n\t"
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"bne 1b\n\t"
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/* Issue the command ACK */
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"str %[ackcmd], [%[gpio_ctrl]]\n\t"
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/* Trap the processor */
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"b .\n\t"
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: : [srcmd] "r" (srcmd), [sdram_reg] "r" (sdram_reg),
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[ackcmd] "r" (ackcmd), [gpio_ctrl] "r" (gpio_ctrl) : "r1");
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}
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static int __init mvebu_armada_pm_init(void)
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{
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struct device_node *np;
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struct device_node *gpio_ctrl_np;
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int ret = 0, i;
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if (!of_machine_is_compatible("marvell,axp-gp"))
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return -ENODEV;
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np = of_find_node_by_name(NULL, "pm_pic");
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if (!np)
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return -ENODEV;
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for (i = 0; i < ARMADA_PIC_NR_GPIOS; i++) {
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char *name;
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struct of_phandle_args args;
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pic_gpios[i] = of_get_named_gpio(np, "ctrl-gpios", i);
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if (pic_gpios[i] < 0) {
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ret = -ENODEV;
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goto out;
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}
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name = kasprintf(GFP_KERNEL, "pic-pin%d", i);
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if (!name) {
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ret = -ENOMEM;
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goto out;
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}
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ret = gpio_request(pic_gpios[i], name);
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if (ret < 0) {
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kfree(name);
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goto out;
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}
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ret = gpio_direction_output(pic_gpios[i], 0);
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if (ret < 0) {
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gpio_free(pic_gpios[i]);
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kfree(name);
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goto out;
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}
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ret = of_parse_phandle_with_fixed_args(np, "ctrl-gpios", 2,
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i, &args);
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if (ret < 0) {
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gpio_free(pic_gpios[i]);
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kfree(name);
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goto out;
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}
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gpio_ctrl_np = args.np;
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pic_raw_gpios[i] = args.args[0];
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}
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gpio_ctrl = of_iomap(gpio_ctrl_np, 0);
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if (!gpio_ctrl)
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return -ENOMEM;
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mvebu_pm_suspend_init(mvebu_armada_pm_enter);
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out:
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of_node_put(np);
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return ret;
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}
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/*
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* Registering the mvebu_board_pm_enter callback must be done before
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* the platform_suspend_ops will be registered. In the same time we
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* also need to have the gpio devices registered. That's why we use a
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* device_initcall_sync which is called after all the device_initcall
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* (used by the gpio device) but before the late_initcall (used to
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* register the platform_suspend_ops)
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*/
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device_initcall_sync(mvebu_armada_pm_init);
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