[U-Boot] [PATCH v2] davinci timer.c: Remove volatiles and memory mapped structures

Nick Thompson nick.thompson at gefanuc.com
Mon Oct 26 17:02:53 CET 2009


Paulraj, Sandeep wrote:
> 
>> Remove volatiles and memory mapped structure accesses and replace with
>> readl and writel macro usage.
>>
>> Signed-off-by: Nick Thompson <nick.thompson at gefanuc.com>
>> ---
>> This patch was originally part of the da830 support patch, but this
>> effort is now being integrated into davinci. As a result, these
>> changes would be have been lost, as no change is required for da830.
>> The changes where request to be kept available however, so here they
>> are.
>>
>>  cpu/arm926ejs/davinci/timer.c |   29 +++++++++++++++++------------
>>  1 files changed, 17 insertions(+), 12 deletions(-)
> 
> I started the process of integrating into my branch and doing some quick tests on other DM parts.
> But, I got 2 checkpatch warnings while running checkpatch.
> One of them I believe is unavoidable because U-boot does not have a linux/io.h
> 
> The other deals with using a typedef. 

I only get one warning with 0.09 of checkpatch. It warns about not adding new typedefs.
The typedef is already there though - I only removed the volatile. No excuse really.

In this case I expect it is fine to just to use a struct instead. Do you want me
to make that change?

> 
> 
>> diff --git a/cpu/arm926ejs/davinci/timer.c b/cpu/arm926ejs/davinci/timer.c
>> index 80751ad..f705a6e 100644
>> --- a/cpu/arm926ejs/davinci/timer.c
>> +++ b/cpu/arm926ejs/davinci/timer.c
>> @@ -38,8 +38,9 @@
>>   */
>>
>>  #include <common.h>
>> +#include <asm/io.h>
>>
>> -typedef volatile struct {
>> +typedef struct {
>>  	u_int32_t	pid12;
>>  	u_int32_t	emumgt;
>>  	u_int32_t	na1;
>> @@ -53,7 +54,7 @@ typedef volatile struct {
>>  	u_int32_t	wdtcr;
>>  } davinci_timer;
>>
>> -davinci_timer		*timer = (davinci_timer *)CONFIG_SYS_TIMERBASE;
>> +static davinci_timer * const timer = (davinci_timer
>> *)CONFIG_SYS_TIMERBASE;
>>
>>  #define TIMER_LOAD_VAL	(CONFIG_SYS_HZ_CLOCK / CONFIG_SYS_HZ)
>>  #define TIM_CLK_DIV	16
>> @@ -64,30 +65,30 @@ static ulong lastinc;
>>  int timer_init(void)
>>  {
>>  	/* We are using timer34 in unchained 32-bit mode, full speed */
>> -	timer->tcr = 0x0;
>> -	timer->tgcr = 0x0;
>> -	timer->tgcr = 0x06 | ((TIM_CLK_DIV - 1) << 8);
>> -	timer->tim34 = 0x0;
>> -	timer->prd34 = TIMER_LOAD_VAL;
>> +	writel(0x0, &timer->tcr);
>> +	writel(0x0, &timer->tgcr);
>> +	writel(0x06 | ((TIM_CLK_DIV - 1) << 8), &timer->tgcr);
>> +	writel(0x0, &timer->tim34);
>> +	writel(TIMER_LOAD_VAL, &timer->prd34);
>>  	lastinc = 0;
>>  	timestamp = 0;
>> -	timer->tcr = 2 << 22;
>> +	writel(2 << 22, &timer->tcr);
>>
>>  	return(0);
>>  }
>>
>>  void reset_timer(void)
>>  {
>> -	timer->tcr = 0x0;
>> -	timer->tim34 = 0;
>> +	writel(0x0, &timer->tcr);
>> +	writel(0x0, &timer->tim34);
>>  	lastinc = 0;
>>  	timestamp = 0;
>> -	timer->tcr = 2 << 22;
>> +	writel(2 << 22, &timer->tcr);
>>  }
>>
>>  static ulong get_timer_raw(void)
>>  {
>> -	ulong now = timer->tim34;
>> +	ulong now = readl(&timer->tim34);
>>
>>  	if (now >= lastinc) {
>>  		/* normal mode */
> 



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