Commit 577d104d authored by Geert Uytterhoeven's avatar Geert Uytterhoeven Committed by Simon Horman
Browse files

ARM: shmobile: R-Car: Improve documentation 



Add more SYSC register documentation.
Use definitions instead of hardcoded numbers.
Comment important operations.

Signed-off-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: default avatarSimon Horman <horms+renesas@verge.net.au>
parent d770e558

arch/arm/mach-shmobile/pm-rcar.c

+32 −14
Original line number Diff line number Diff line
@@ -15,15 +15,29 @@ 
#include <asm/io.h>

#include "pm-rcar.h"



/* SYSC */

#define SYSCSR 0x00

#define SYSCISR 0x04

#define SYSCISCR 0x08

/* SYSC Common */

#define SYSCSR			0x00	/* SYSC Status Register */

#define SYSCISR			0x04	/* Interrupt Status Register */

#define SYSCISCR		0x08	/* Interrupt Status Clear Register */

#define SYSCIER			0x0c	/* Interrupt Enable Register */

#define SYSCIMR			0x10	/* Interrupt Mask Register */



/* SYSC Status Register */

#define SYSCSR_PONENB		1	/* Ready for power resume requests */

#define SYSCSR_POFFENB		0	/* Ready for power shutoff requests */



/*

 * Power Control Register Offsets inside the register block for each domain

 * Note: The "CR" registers for ARM cores exist on H1 only

 *       Use WFI to power off, CPG/APMU to resume ARM cores on R-Car Gen2

 */

#define PWRSR_OFFS		0x00	/* Power Status Register */

#define PWROFFCR_OFFS		0x04	/* Power Shutoff Control Register */

#define PWROFFSR_OFFS		0x08	/* Power Shutoff Status Register */

#define PWRONCR_OFFS		0x0c	/* Power Resume Control Register */

#define PWRONSR_OFFS		0x10	/* Power Resume Status Register */

#define PWRER_OFFS		0x14	/* Power Shutoff/Resume Error */



#define PWRSR_OFFS 0x00

#define PWROFFCR_OFFS 0x04

#define PWRONCR_OFFS 0x0c

#define PWRER_OFFS 0x14



#define SYSCSR_RETRIES		100

#define SYSCSR_DELAY_US		1
@@ -39,6 +53,7 @@ static int rcar_sysc_pwr_on_off(struct rcar_sysc_ch *sysc_ch, 
{

	int k;



	/* Wait until SYSC is ready to accept a power request */

	for (k = 0; k < SYSCSR_RETRIES; k++) {

		if (ioread32(rcar_sysc_base + SYSCSR) & (1 << sr_bit))

			break;
@@ -48,6 +63,7 @@ static int rcar_sysc_pwr_on_off(struct rcar_sysc_ch *sysc_ch, 
	if (k == SYSCSR_RETRIES)

		return -EAGAIN;



	/* Submit power shutoff or power resume request */

	iowrite32(1 << sysc_ch->chan_bit,

		  rcar_sysc_base + sysc_ch->chan_offs + reg_offs);
@@ -56,12 +72,12 @@ static int rcar_sysc_pwr_on_off(struct rcar_sysc_ch *sysc_ch, 


static int rcar_sysc_pwr_off(struct rcar_sysc_ch *sysc_ch)

{

	return rcar_sysc_pwr_on_off(sysc_ch, 0, PWROFFCR_OFFS);

	return rcar_sysc_pwr_on_off(sysc_ch, SYSCSR_POFFENB, PWROFFCR_OFFS);

}



static int rcar_sysc_pwr_on(struct rcar_sysc_ch *sysc_ch)

{

	return rcar_sysc_pwr_on_off(sysc_ch, 1, PWRONCR_OFFS);

	return rcar_sysc_pwr_on_off(sysc_ch, SYSCSR_PONENB, PWRONCR_OFFS);

}



static int rcar_sysc_update(struct rcar_sysc_ch *sysc_ch,
@@ -78,6 +94,7 @@ static int rcar_sysc_update(struct rcar_sysc_ch *sysc_ch, 


	iowrite32(isr_mask, rcar_sysc_base + SYSCISCR);



	/* Submit power shutoff or resume request until it was accepted */

	do {

		ret = on_off_fn(sysc_ch);

		if (ret)
@@ -87,6 +104,7 @@ static int rcar_sysc_update(struct rcar_sysc_ch *sysc_ch, 
				  sysc_ch->chan_offs + PWRER_OFFS);

	} while (status & chan_mask);



	/* Wait until the power shutoff or resume request has completed * */

	for (k = 0; k < SYSCISR_RETRIES; k++) {

		if (ioread32(rcar_sysc_base + SYSCISR) & isr_mask)

			break;