arch/arm/mach-s5p64x0/include/mach/pm-core.h

/* linux/arch/arm/mach-s5p64x0/include/mach/pm-core.h
 *
 * Copyright (c) 2011 Samsung Electronics Co., Ltd.
 *		http://www.samsung.com
 *
 * S5P64X0 - PM core support for arch/arm/plat-samsung/pm.c
 *
 * Based on PM core support for S3C64XX by Ben Dooks
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/serial_s3c.h>

#include <mach/regs-gpio.h>

static inline void s3c_pm_debug_init_uart(void)
{
	u32 tmp = __raw_readl(S5P64X0_CLK_GATE_PCLK);

	/*
	 * As a note, since the S5P64X0 UARTs generally have multiple
	 * clock sources, we simply enable PCLK at the moment and hope
	 * that the resume settings for the UART are suitable for the
	 * use with PCLK.
	 */
	tmp |= S5P64X0_CLK_GATE_PCLK_UART0;
	tmp |= S5P64X0_CLK_GATE_PCLK_UART1;
	tmp |= S5P64X0_CLK_GATE_PCLK_UART2;
	tmp |= S5P64X0_CLK_GATE_PCLK_UART3;

	__raw_writel(tmp, S5P64X0_CLK_GATE_PCLK);
	udelay(10);
}

static inline void s3c_pm_arch_prepare_irqs(void)
{
	/* VIC should have already been taken care of */

	/* clear any pending EINT0 interrupts */
	__raw_writel(__raw_readl(S5P64X0_EINT0PEND), S5P64X0_EINT0PEND);
}

static inline void s3c_pm_arch_stop_clocks(void) { }
static inline void s3c_pm_arch_show_resume_irqs(void) { }

/*
 * make these defines, we currently do not have any need to change
 * the IRQ wake controls depending on the CPU we are running on
 */
#define s3c_irqwake_eintallow	((1 << 16) - 1)
#define s3c_irqwake_intallow	(~0)

static inline void s3c_pm_arch_update_uart(void __iomem *regs,
					struct pm_uart_save *save)
{
	u32 ucon = __raw_readl(regs + S3C2410_UCON);
	u32 ucon_clk = ucon & S3C6400_UCON_CLKMASK;
	u32 save_clk = save->ucon & S3C6400_UCON_CLKMASK;
	u32 new_ucon;
	u32 delta;

	/*
	 * S5P64X0 UART blocks only support level interrupts, so ensure that
	 * when we restore unused UART blocks we force the level interrupt
	 * settings.
	 */
	save->ucon |= S3C2410_UCON_TXILEVEL | S3C2410_UCON_RXILEVEL;

	/*
	 * We have a constraint on changing the clock type of the UART
	 * between UCLKx and PCLK, so ensure that when we restore UCON
	 * that the CLK field is correctly modified if the bootloader
	 * has changed anything.
	 */
	if (ucon_clk != save_clk) {
		new_ucon = save->ucon;
		delta = ucon_clk ^ save_clk;

		/*
		 * change from UCLKx => wrong PCLK,
		 * either UCLK can be tested for by a bit-test
		 * with UCLK0
		 */
		if (ucon_clk & S3C6400_UCON_UCLK0 &&
		!(save_clk & S3C6400_UCON_UCLK0) &&
		delta & S3C6400_UCON_PCLK2) {
			new_ucon &= ~S3C6400_UCON_UCLK0;
		} else if (delta == S3C6400_UCON_PCLK2) {
			/*
			 * as a precaution, don't change from
			 * PCLK2 => PCLK or vice-versa
			 */
			new_ucon ^= S3C6400_UCON_PCLK2;
		}

		S3C_PMDBG("ucon change %04x => %04x (save=%04x)\n",
			ucon, new_ucon, save->ucon);
		save->ucon = new_ucon;
	}
}

static inline void s3c_pm_restored_gpios(void)
{
	/* ensure sleep mode has been cleared from the system */
	__raw_writel(0, S5P64X0_SLPEN);
}

static inline void samsung_pm_saved_gpios(void)
{
	/*
	 * turn on the sleep mode and keep it there, as it seems that during
	 * suspend the xCON registers get re-set and thus you can end up with
	 * problems between going to sleep and resuming.
	 */
	__raw_writel(S5P64X0_SLPEN_USE_xSLP, S5P64X0_SLPEN);
}