[U-Boot] [PATCH] arm/pxa: fix and cleanup of pxa_mem_setup macro v2

Marek Vasut marek.vasut at gmail.com
Mon May 31 16:30:33 CEST 2010 

Dne Po 31. května 2010 16:02:49 Mikhail Kshevetskiy napsal(a):
> WARNING: This macro do not assume the values for K0DB4, KxDB2, KxFREE,
>          K1RUN, K2RUN and APD bits of CONFIG_SYS_MDREFR_VAL as it was
>          done early on many pxa platforms. All pxa developers that plan
>          to use this macro should check the validity of their MDREFR
> values.
> 
> v1:
>   * strict following to section 6.4.10 of Intel PXA27xx Developer's Manual.
>   * use r7 to store CONFIG_SYS_MDREFR_VAL as r6 is used in pxa_wait_ticks.
> 
> v2:
>   * rename pxa_mem_setup macro to pxa2xx_mem_setup
>   * setting of MDREFR[K1RUN] and MDREFR[K2RUN] bits may be optional
>   * skip certain configuration steps if SDRAM is not present/configured
>   * improve/fix comments
> 
> Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy at gmail.com>
> ---
>  arch/arm/include/asm/arch-pxa/macro.h |   82
> ++++++++++++++++++++++----------- board/vpac270/lowlevel_init.S         | 
>   2 +-
>  2 files changed, 56 insertions(+), 28 deletions(-)
> 
> diff --git a/arch/arm/include/asm/arch-pxa/macro.h
> b/arch/arm/include/asm/arch-pxa/macro.h index 1f1759b..e2ddfe9 100644
> --- a/arch/arm/include/asm/arch-pxa/macro.h
> +++ b/arch/arm/include/asm/arch-pxa/macro.h
> @@ -102,11 +102,15 @@
>  /*
>   * This macro sets up the Memory controller of the PXA2xx CPU
>   *
> - * Clobbered regs: r3, r4, r5
> + * Clobbered regs: r3, r4, r5, r6, r7
> + *
> + * See section 6.4.10 of Intel PXA2xx Processor Developer's Manual
> + *  
> http://www.marvell.com/products/processors/applications/pxa_family/pxa_27x
> _dev_man.pdf */
> -.macro	pxa_mem_setup
> +.macro	pxa2xx_mem_setup
>  	/* This comes handy when setting MDREFR */
>  	ldr	r3, =MEMC_BASE
> +	ldr	r7, =CONFIG_SYS_MDREFR_VAL

Push this below.
> 
>  	/*
>  	 * 1) Initialize Asynchronous static memory controller
> @@ -149,51 +153,68 @@
>  	 */
> 
>  	/*
> -	 * Before accessing MDREFR we need a valid DRI field, so we set
> -	 * this to power on defaults + DRI field.
> +	 * Before accessing MDREFR we need a valid DRI field.
> +	 * Also we must properly configure MDREFR[K0DB2] and MDREFR[K0DB4].
> +	 * Optionaly we can set MDREFR[KxFREE] bits.
> +	 * So we set MDREFR to power on defaults + (DRI, K0DB2, K0DB4, KxFREE)
> +	 * fields from the config.
> +	 *
> +	 * WARNING: K0DB2 and K0DB4 bits are usually set, while KxFREE bits
> +	 *          are usually unset.

Not true. Why is such a warning here ?

>  	 */
>  	ldr	r5, [r3, #MDREFR_OFFSET]
> -	bic	r5, r5, #0x0ff
> -	bic	r5, r5, #0xf00	/* MDREFR user config with zeroed DRI */
> -
> -	ldr	r4, =CONFIG_SYS_MDREFR_VAL
> -	mov	r6, r4
> -	lsl	r4, #20
> -	lsr	r4, #20		/* Get a valid DRI field */
> -
> -	orr	r5, r5, r4	/* MDREFR user config with correct DRI */
> +	ldr	r4, =( 0xFFF | MDREFR_K0DB4 | MDREFR_K0DB2 | \
> +		       MDREFR_K0FREE | MDREFR_K1FREE | MDREFR_K2FREE )

Looks good. But then, can't you just write the full custom config here and just 
adjust the necessary bits? (K0RUN, SLFRSH, APD, E1PIN) ? That might make it even 
less complicated.

> +	bic	r5, r5, r4	/* clear DRI, K0DB2, K0DB4, KxFREE fields */
> +	and	r4, r7, r4
> +	orr	r5, r5, r4	/* use custom DRI, K0DB2, K0DB4, KxFREE */
> 
>  	orr	r5, #MDREFR_K0RUN
>  	orr	r5, #MDREFR_SLFRSH
>  	bic	r5, #MDREFR_APD
> -	bic	r5, #MDREFR_E1PIN
> +
> +	/* enable them later, if SDRAM is present */
> +	bic	r5, #( MDREFR_E1PIN | MDREFR_K1RUN | MDREFR_K2RUN | \
> +				      MDREFR_K1DB2 | MDREFR_K2DB2 )
> 
>  	str	r5, [r3, #MDREFR_OFFSET]
> -	ldr	r4, [r3, #MDREFR_OFFSET]
> +	ldr	r5, [r3, #MDREFR_OFFSET]
> 
>  	/*
>  	 * 5) Initialize Synchronous Static Memory (Flash/Peripherals)
>  	 */
> 
> -	/* Initialize SXCNFG register. Assert the enable bits.
> -	 *
> -	 * Write SXMRS to cause an MRS command to all enabled banks of
> -	 * synchronous static memory. Note that SXLCR need not be written
> -	 * at this time.
> +	/* Initialize SXCNFG register to enable synchronous flash memory.
> +	 * While the synchronous flash banks are being configured, the SDRAM
> +	 * banks must be disabled and MDREFR[APD] must be de-asserted.
>  	 */
>  	write32rb	(MEMC_BASE + SXCNFG_OFFSET), CONFIG_SYS_SXCNFG_VAL
> 
>  	/*
> -	 * 6) Initialize SDRAM
> +	 * 6) Initialize SDRAM,
> +	 *    If SDRAM present, then MDREFR[K1RUN] and/or MDREFR[K1RUN] bits

and/or K2RUN ?

> +	 *    must be set. Also we must properly configure MDREFR[K1DB2] and
> +	 *    MDREFR[K2DB2] in this case.
> +	 *
> +	 *    WARNING: K1DB2 and K2DB2 bits are usually set if SDRAM present
>  	 */
> 
> +#if (CONFIG_SYS_MDREFR_VAL & (MDREFR_K1RUN | MDREFR_K2RUN))
> +	and	r4, r7, #( MDREFR_K1RUN | MDREFR_K2RUN | \
> +			   MDREFR_K1DB2 | MDREFR_K2DB2 )
> +	ldr	r6, [r3, #MDREFR_OFFSET]
> +	orr	r6, r6, r4
> +	str	r6, [r3, #MDREFR_OFFSET]
> +	ldr	r6, [r3, #MDREFR_OFFSET]
> +
>  	bic	r6, #MDREFR_SLFRSH
>  	str	r6, [r3, #MDREFR_OFFSET]
> -	ldr	r4, [r3, #MDREFR_OFFSET]
> +	ldr	r6, [r3, #MDREFR_OFFSET]
> 
>  	orr	r6, #MDREFR_E1PIN
>  	str	r6, [r3, #MDREFR_OFFSET]
> -	ldr	r4, [r3, #MDREFR_OFFSET]
> +	ldr	r6, [r3, #MDREFR_OFFSET]
> +#endif

This can be done unconditionally. I'd like to implement memory size 
autodetection and if there was such a condition, it'd have to go away eventually 
anyway. Also, you put too much into the condition I think.
> 
>  	/*
>  	 * 7) Write MDCNFG with MDCNFG:DEx deasserted (set to 0), to configure
> @@ -209,6 +230,7 @@
>  	str	r4, [r3, #MDCNFG_OFFSET]
>  	ldr	r4, [r3, #MDCNFG_OFFSET]
> 
> +#if (CONFIG_SYS_MDREFR_VAL & (MDREFR_K1RUN | MDREFR_K2RUN))
>  	/* Wait for the clock to the SDRAMs to stabilize, 100..200 usec. */
>  	pxa_wait_ticks	0x300
> 
> @@ -226,7 +248,7 @@
>  .endr
> 
>  	/*
> -	 * 9) Write MDCNFG with enable bits asserted (MDCNFG:DEx set to 1).
> +	 * 9) Set custom MDCNFG[DEx] bits to enable required SDRAM partitions
>  	 */
> 
>  	ldr	r5, =CONFIG_SYS_MDCNFG_VAL
> @@ -238,19 +260,25 @@
>  	ldr     r4, [r3, #MDCNFG_OFFSET]
> 
>  	/*
> -	 * 10) Write MDMRS.
> +	 * 10) Write to MDMRS register to trigger an MRS command to
> +	 *     all enabled banks of SDRAM. For each SDRAM partition pair
> +	 *     that has one or both partitions enabled, this forces a pass
> +	 *     through the MRS state and a return to NOP.
>  	 */
> 
>  	ldr     r4, =CONFIG_SYS_MDMRS_VAL
>  	str     r4, [r3, #MDMRS_OFFSET]
>  	ldr     r4, [r3, #MDMRS_OFFSET]
> +#endif

Remove the conditions please.
> 
>  	/*
> -	 * 11) Enable APD
> +	 * 11) Optionaly enable auto-power-down by setting MDREFR[APD]
> +	 *
> +	 *     WARNING: APD bit is usually set.
>  	 */
> 
>  	ldr	r4, [r3, #MDREFR_OFFSET]
> -	and	r6, r6, #MDREFR_APD
> +	and	r6, r7, #MDREFR_APD
>  	orr	r4, r4, r6
>  	str	r4, [r3, #MDREFR_OFFSET]
>  	ldr	r4, [r3, #MDREFR_OFFSET]
> diff --git a/board/vpac270/lowlevel_init.S b/board/vpac270/lowlevel_init.S
> index ec0d12c..a327ebd 100644
> --- a/board/vpac270/lowlevel_init.S
> +++ b/board/vpac270/lowlevel_init.S
> @@ -32,7 +32,7 @@
>  lowlevel_init:
>  	pxa_gpio_setup
>  	pxa_wait_ticks	0x8000
> -	pxa_mem_setup
> +	pxa2xx_mem_setup
>  	pxa_wakeup
>  	pxa_intr_setup
>  	pxa_clock_setup

Keep up with it, good work.

Cheers

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