| /* | 
 |  * arch/arm/mach-at91/pm_slow_clock.S | 
 |  * | 
 |  *  Copyright (C) 2006 Savin Zlobec | 
 |  * | 
 |  * AT91SAM9 support: | 
 |  *  Copyright (C) 2007 Anti Sullin <anti.sullin@artecdesign.ee | 
 |  * | 
 |  * 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/linkage.h> | 
 | #include <mach/hardware.h> | 
 | #include <mach/at91_pmc.h> | 
 |  | 
 | #if defined(CONFIG_ARCH_AT91RM9200) | 
 | #include <mach/at91rm9200_mc.h> | 
 | #elif defined(CONFIG_ARCH_AT91CAP9) | 
 | #include <mach/at91cap9_ddrsdr.h> | 
 | #elif defined(CONFIG_ARCH_AT91SAM9G45) | 
 | #include <mach/at91sam9_ddrsdr.h> | 
 | #else | 
 | #include <mach/at91sam9_sdramc.h> | 
 | #endif | 
 |  | 
 |  | 
 | #ifdef CONFIG_ARCH_AT91SAM9263 | 
 | /* | 
 |  * FIXME either or both the SDRAM controllers (EB0, EB1) might be in use; | 
 |  * handle those cases both here and in the Suspend-To-RAM support. | 
 |  */ | 
 | #warning Assuming EB1 SDRAM controller is *NOT* used | 
 | #endif | 
 |  | 
 | /* | 
 |  * When SLOWDOWN_MASTER_CLOCK is defined we will also slow down the Master | 
 |  * clock during suspend by adjusting its prescalar and divisor. | 
 |  * NOTE: This hasn't been shown to be stable on SAM9s; and on the RM9200 there | 
 |  *       are errata regarding adjusting the prescalar and divisor. | 
 |  */ | 
 | #undef SLOWDOWN_MASTER_CLOCK | 
 |  | 
 | #define MCKRDY_TIMEOUT		1000 | 
 | #define MOSCRDY_TIMEOUT 	1000 | 
 | #define PLLALOCK_TIMEOUT	1000 | 
 | #define PLLBLOCK_TIMEOUT	1000 | 
 |  | 
 |  | 
 | /* | 
 |  * Wait until master clock is ready (after switching master clock source) | 
 |  */ | 
 | 	.macro wait_mckrdy | 
 | 	mov	r4, #MCKRDY_TIMEOUT | 
 | 1:	sub	r4, r4, #1 | 
 | 	cmp	r4, #0 | 
 | 	beq	2f | 
 | 	ldr	r3, [r1, #(AT91_PMC_SR - AT91_PMC)] | 
 | 	tst	r3, #AT91_PMC_MCKRDY | 
 | 	beq	1b | 
 | 2: | 
 | 	.endm | 
 |  | 
 | /* | 
 |  * Wait until master oscillator has stabilized. | 
 |  */ | 
 | 	.macro wait_moscrdy | 
 | 	mov	r4, #MOSCRDY_TIMEOUT | 
 | 1:	sub	r4, r4, #1 | 
 | 	cmp	r4, #0 | 
 | 	beq	2f | 
 | 	ldr	r3, [r1, #(AT91_PMC_SR - AT91_PMC)] | 
 | 	tst	r3, #AT91_PMC_MOSCS | 
 | 	beq	1b | 
 | 2: | 
 | 	.endm | 
 |  | 
 | /* | 
 |  * Wait until PLLA has locked. | 
 |  */ | 
 | 	.macro wait_pllalock | 
 | 	mov	r4, #PLLALOCK_TIMEOUT | 
 | 1:	sub	r4, r4, #1 | 
 | 	cmp	r4, #0 | 
 | 	beq	2f | 
 | 	ldr	r3, [r1, #(AT91_PMC_SR - AT91_PMC)] | 
 | 	tst	r3, #AT91_PMC_LOCKA | 
 | 	beq	1b | 
 | 2: | 
 | 	.endm | 
 |  | 
 | /* | 
 |  * Wait until PLLB has locked. | 
 |  */ | 
 | 	.macro wait_pllblock | 
 | 	mov	r4, #PLLBLOCK_TIMEOUT | 
 | 1:	sub	r4, r4, #1 | 
 | 	cmp	r4, #0 | 
 | 	beq	2f | 
 | 	ldr	r3, [r1, #(AT91_PMC_SR - AT91_PMC)] | 
 | 	tst	r3, #AT91_PMC_LOCKB | 
 | 	beq	1b | 
 | 2: | 
 | 	.endm | 
 |  | 
 | 	.text | 
 |  | 
 | ENTRY(at91_slow_clock) | 
 | 	/* Save registers on stack */ | 
 | 	stmfd	sp!, {r0 - r12, lr} | 
 |  | 
 | 	/* | 
 | 	 * Register usage: | 
 | 	 *  R1 = Base address of AT91_PMC | 
 | 	 *  R2 = Base address of RAM Controller (SDRAM, DDRSDR, or AT91_SYS) | 
 | 	 *  R3 = temporary register | 
 | 	 *  R4 = temporary register | 
 | 	 *  R5 = Base address of second RAM Controller or 0 if not present | 
 | 	 */ | 
 | 	ldr	r1, .at91_va_base_pmc | 
 | 	ldr	r2, .at91_va_base_sdramc | 
 | 	ldr	r5, .at91_va_base_ramc1 | 
 |  | 
 | 	/* Drain write buffer */ | 
 | 	mcr	p15, 0, r0, c7, c10, 4 | 
 |  | 
 | #ifdef CONFIG_ARCH_AT91RM9200 | 
 | 	/* Put SDRAM in self-refresh mode */ | 
 | 	mov	r3, #1 | 
 | 	str	r3, [r2, #AT91_SDRAMC_SRR] | 
 | #elif defined(CONFIG_ARCH_AT91CAP9) \ | 
 | 	|| defined(CONFIG_ARCH_AT91SAM9G45) | 
 |  | 
 | 	/* prepare for DDRAM self-refresh mode */ | 
 | 	ldr	r3, [r2, #AT91_DDRSDRC_LPR] | 
 | 	str	r3, .saved_sam9_lpr | 
 | 	bic	r3, #AT91_DDRSDRC_LPCB | 
 | 	orr	r3, #AT91_DDRSDRC_LPCB_SELF_REFRESH | 
 |  | 
 | 	/* figure out if we use the second ram controller */ | 
 | 	cmp	r5, #0 | 
 | 	ldrne	r4, [r5, #AT91_DDRSDRC_LPR] | 
 | 	strne	r4, .saved_sam9_lpr1 | 
 | 	bicne	r4, #AT91_DDRSDRC_LPCB | 
 | 	orrne	r4, #AT91_DDRSDRC_LPCB_SELF_REFRESH | 
 |  | 
 | 	/* Enable DDRAM self-refresh mode */ | 
 | 	str	r3, [r2, #AT91_DDRSDRC_LPR] | 
 | 	strne	r4, [r5, #AT91_DDRSDRC_LPR] | 
 | #else | 
 | 	/* Enable SDRAM self-refresh mode */ | 
 | 	ldr	r3, [r2, #AT91_SDRAMC_LPR] | 
 | 	str	r3, .saved_sam9_lpr | 
 |  | 
 | 	bic	r3, #AT91_SDRAMC_LPCB | 
 | 	orr	r3, #AT91_SDRAMC_LPCB_SELF_REFRESH | 
 | 	str	r3, [r2, #AT91_SDRAMC_LPR] | 
 | #endif | 
 |  | 
 | 	/* Save Master clock setting */ | 
 | 	ldr	r3, [r1, #(AT91_PMC_MCKR - AT91_PMC)] | 
 | 	str	r3, .saved_mckr | 
 |  | 
 | 	/* | 
 | 	 * Set the Master clock source to slow clock | 
 | 	 */ | 
 | 	bic	r3, r3, #AT91_PMC_CSS | 
 | 	str	r3, [r1, #(AT91_PMC_MCKR - AT91_PMC)] | 
 |  | 
 | 	wait_mckrdy | 
 |  | 
 | #ifdef SLOWDOWN_MASTER_CLOCK | 
 | 	/* | 
 | 	 * Set the Master Clock PRES and MDIV fields. | 
 | 	 * | 
 | 	 * See AT91RM9200 errata #27 and #28 for details. | 
 | 	 */ | 
 | 	mov	r3, #0 | 
 | 	str	r3, [r1, #(AT91_PMC_MCKR - AT91_PMC)] | 
 |  | 
 | 	wait_mckrdy | 
 | #endif | 
 |  | 
 | 	/* Save PLLA setting and disable it */ | 
 | 	ldr	r3, [r1, #(AT91_CKGR_PLLAR - AT91_PMC)] | 
 | 	str	r3, .saved_pllar | 
 |  | 
 | 	mov	r3, #AT91_PMC_PLLCOUNT | 
 | 	orr	r3, r3, #(1 << 29)		/* bit 29 always set */ | 
 | 	str	r3, [r1, #(AT91_CKGR_PLLAR - AT91_PMC)] | 
 |  | 
 | 	/* Save PLLB setting and disable it */ | 
 | 	ldr	r3, [r1, #(AT91_CKGR_PLLBR - AT91_PMC)] | 
 | 	str	r3, .saved_pllbr | 
 |  | 
 | 	mov	r3, #AT91_PMC_PLLCOUNT | 
 | 	str	r3, [r1, #(AT91_CKGR_PLLBR - AT91_PMC)] | 
 |  | 
 | 	/* Turn off the main oscillator */ | 
 | 	ldr	r3, [r1, #(AT91_CKGR_MOR - AT91_PMC)] | 
 | 	bic	r3, r3, #AT91_PMC_MOSCEN | 
 | 	str	r3, [r1, #(AT91_CKGR_MOR - AT91_PMC)] | 
 |  | 
 | 	/* Wait for interrupt */ | 
 | 	mcr	p15, 0, r0, c7, c0, 4 | 
 |  | 
 | 	/* Turn on the main oscillator */ | 
 | 	ldr	r3, [r1, #(AT91_CKGR_MOR - AT91_PMC)] | 
 | 	orr	r3, r3, #AT91_PMC_MOSCEN | 
 | 	str	r3, [r1, #(AT91_CKGR_MOR - AT91_PMC)] | 
 |  | 
 | 	wait_moscrdy | 
 |  | 
 | 	/* Restore PLLB setting */ | 
 | 	ldr	r3, .saved_pllbr | 
 | 	str	r3, [r1, #(AT91_CKGR_PLLBR - AT91_PMC)] | 
 |  | 
 | 	tst	r3, #(AT91_PMC_MUL &  0xff0000) | 
 | 	bne	1f | 
 | 	tst	r3, #(AT91_PMC_MUL & ~0xff0000) | 
 | 	beq	2f | 
 | 1: | 
 | 	wait_pllblock | 
 | 2: | 
 |  | 
 | 	/* Restore PLLA setting */ | 
 | 	ldr	r3, .saved_pllar | 
 | 	str	r3, [r1, #(AT91_CKGR_PLLAR - AT91_PMC)] | 
 |  | 
 | 	tst	r3, #(AT91_PMC_MUL &  0xff0000) | 
 | 	bne	3f | 
 | 	tst	r3, #(AT91_PMC_MUL & ~0xff0000) | 
 | 	beq	4f | 
 | 3: | 
 | 	wait_pllalock | 
 | 4: | 
 |  | 
 | #ifdef SLOWDOWN_MASTER_CLOCK | 
 | 	/* | 
 | 	 * First set PRES if it was not 0, | 
 | 	 * than set CSS and MDIV fields. | 
 | 	 * | 
 | 	 * See AT91RM9200 errata #27 and #28 for details. | 
 | 	 */ | 
 | 	ldr	r3, .saved_mckr | 
 | 	tst	r3, #AT91_PMC_PRES | 
 | 	beq	2f | 
 | 	and	r3, r3, #AT91_PMC_PRES | 
 | 	str	r3, [r1, #(AT91_PMC_MCKR - AT91_PMC)] | 
 |  | 
 | 	wait_mckrdy | 
 | #endif | 
 |  | 
 | 	/* | 
 | 	 * Restore master clock setting | 
 | 	 */ | 
 | 2:	ldr	r3, .saved_mckr | 
 | 	str	r3, [r1, #(AT91_PMC_MCKR - AT91_PMC)] | 
 |  | 
 | 	wait_mckrdy | 
 |  | 
 | #ifdef CONFIG_ARCH_AT91RM9200 | 
 | 	/* Do nothing - self-refresh is automatically disabled. */ | 
 | #elif defined(CONFIG_ARCH_AT91CAP9) \ | 
 | 	|| defined(CONFIG_ARCH_AT91SAM9G45) | 
 | 	/* Restore LPR on AT91 with DDRAM */ | 
 | 	ldr	r3, .saved_sam9_lpr | 
 | 	str	r3, [r2, #AT91_DDRSDRC_LPR] | 
 |  | 
 | 	/* if we use the second ram controller */ | 
 | 	cmp	r5, #0 | 
 | 	ldrne	r4, .saved_sam9_lpr1 | 
 | 	strne	r4, [r5, #AT91_DDRSDRC_LPR] | 
 |  | 
 | #else | 
 | 	/* Restore LPR on AT91 with SDRAM */ | 
 | 	ldr	r3, .saved_sam9_lpr | 
 | 	str	r3, [r2, #AT91_SDRAMC_LPR] | 
 | #endif | 
 |  | 
 | 	/* Restore registers, and return */ | 
 | 	ldmfd	sp!, {r0 - r12, pc} | 
 |  | 
 |  | 
 | .saved_mckr: | 
 | 	.word 0 | 
 |  | 
 | .saved_pllar: | 
 | 	.word 0 | 
 |  | 
 | .saved_pllbr: | 
 | 	.word 0 | 
 |  | 
 | .saved_sam9_lpr: | 
 | 	.word 0 | 
 |  | 
 | .saved_sam9_lpr1: | 
 | 	.word 0 | 
 |  | 
 | .at91_va_base_pmc: | 
 | 	.word AT91_VA_BASE_SYS + AT91_PMC | 
 |  | 
 | #ifdef CONFIG_ARCH_AT91RM9200 | 
 | .at91_va_base_sdramc: | 
 | 	.word AT91_VA_BASE_SYS | 
 | #elif defined(CONFIG_ARCH_AT91CAP9) \ | 
 | 	|| defined(CONFIG_ARCH_AT91SAM9G45) | 
 | .at91_va_base_sdramc: | 
 | 	.word AT91_VA_BASE_SYS + AT91_DDRSDRC0 | 
 | #else | 
 | .at91_va_base_sdramc: | 
 | 	.word AT91_VA_BASE_SYS + AT91_SDRAMC0 | 
 | #endif | 
 |  | 
 | .at91_va_base_ramc1: | 
 | #if defined(CONFIG_ARCH_AT91SAM9G45) | 
 | 	.word AT91_VA_BASE_SYS + AT91_DDRSDRC1 | 
 | #else | 
 | 	.word 0 | 
 | #endif | 
 |  | 
 | ENTRY(at91_slow_clock_sz) | 
 | 	.word .-at91_slow_clock |