Ezequiel Garcia | e1cb367 | 2013-08-22 12:49:07 -0300 | [diff] [blame] | 1 | /* |
| 2 | * Power Management driver for Marvell Kirkwood SoCs |
| 3 | * |
| 4 | * Copyright (C) 2013 Ezequiel Garcia <ezequiel@free-electrons.com> |
| 5 | * Copyright (C) 2010 Simon Guinot <sguinot@lacie.com> |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License, |
| 9 | * version 2 of the License. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU General Public License for more details. |
| 15 | */ |
| 16 | |
| 17 | #include <linux/kernel.h> |
| 18 | #include <linux/suspend.h> |
| 19 | #include <linux/io.h> |
| 20 | #include <mach/bridge-regs.h> |
| 21 | |
| 22 | static void __iomem *ddr_operation_base; |
| 23 | |
| 24 | static void kirkwood_low_power(void) |
| 25 | { |
| 26 | u32 mem_pm_ctrl; |
| 27 | |
| 28 | mem_pm_ctrl = readl(MEMORY_PM_CTRL); |
| 29 | |
| 30 | /* Set peripherals to low-power mode */ |
| 31 | writel_relaxed(~0, MEMORY_PM_CTRL); |
| 32 | |
| 33 | /* Set DDR in self-refresh */ |
| 34 | writel_relaxed(0x7, ddr_operation_base); |
| 35 | |
| 36 | /* |
| 37 | * Set CPU in wait-for-interrupt state. |
| 38 | * This disables the CPU core clocks, |
| 39 | * the array clocks, and also the L2 controller. |
| 40 | */ |
| 41 | cpu_do_idle(); |
| 42 | |
| 43 | writel_relaxed(mem_pm_ctrl, MEMORY_PM_CTRL); |
| 44 | } |
| 45 | |
| 46 | static int kirkwood_suspend_enter(suspend_state_t state) |
| 47 | { |
| 48 | switch (state) { |
| 49 | case PM_SUSPEND_STANDBY: |
| 50 | kirkwood_low_power(); |
| 51 | break; |
| 52 | default: |
| 53 | return -EINVAL; |
| 54 | } |
| 55 | return 0; |
| 56 | } |
| 57 | |
| 58 | static int kirkwood_pm_valid_standby(suspend_state_t state) |
| 59 | { |
| 60 | return state == PM_SUSPEND_STANDBY; |
| 61 | } |
| 62 | |
| 63 | static const struct platform_suspend_ops kirkwood_suspend_ops = { |
| 64 | .enter = kirkwood_suspend_enter, |
| 65 | .valid = kirkwood_pm_valid_standby, |
| 66 | }; |
| 67 | |
| 68 | int __init kirkwood_pm_init(void) |
| 69 | { |
| 70 | ddr_operation_base = ioremap(DDR_OPERATION_BASE, 4); |
| 71 | suspend_set_ops(&kirkwood_suspend_ops); |
| 72 | return 0; |
| 73 | } |