Re: [PATCH 05/10] i.MX23/28: Fix setting of lcd clock

From: Gregory CLEMENT <gregory.clement@free-electrons.com>
To: Sascha Hauer <s.hauer@pengutronix.de>
Cc: barebox@lists.infradead.org
Subject: Re: [PATCH 05/10] i.MX23/28: Fix setting of lcd clock
Date: Thu, 20 Jan 2011 18:52:39 +0100	[thread overview]
Message-ID: <4D387667.5060607@free-electrons.com> (raw)
In-Reply-To: <20110120145741.GY9041@pengutronix.de>

On 01/20/2011 03:57 PM, Sascha Hauer wrote:
> On Thu, Jan 20, 2011 at 03:01:47PM +0100, Gregory CLEMENT wrote:
>> On 01/20/2011 10:46 AM, Sascha Hauer wrote:
>>> Use the correct bitmask for masking out which is
>>> SET_PIXFRAC(MASK_PIXFRAC)
>>>
>>
>> I was just about to send you the same kind of patch, as this bug bit me during
>> kernel boot when using cpufreq.
>>
>> As you are working on imx23 and video driver, what do you think of my previous
>> patches ? I sent them in January the 4th:
>>
>> ARM STM/i.MX: Add possibility to choose the bit per pixel for STM
>>     video driver
> 
> This looks ok.
> 
>> ARM STM/i.MX: Add possibility to select the data mode for stm video
>>       driver ( DCn signal is high )
> 
> Looks ok. What is this pin good for? Is this bit used in conjunction
> with other bits which happen to have the right value for you?
> 

You made me dig in the datasheet and check my code. And finally this
patch is pointless! The DCn signal which seems related to LCD_RS is
only used in MPU interface whereas we use Dotclock interface.
I just checked again and without it, my LCD still worked. It seems
that I forgot to test this patch alone, as my configuration need
the following patch to work, I didn't notice this patch did nothing.
Sorry for this fake patch :(

>> ARM STM/i.MX: Add the reset control of LCD
> 
> We use the same pin as gpio and toggle it in the platform specific hook,
> so I could rebase my chumby patch on this one.
> 
> For the last two patches I prefer having flags in the platform data
> rather than having a u32 for a single flag.
> 
How could we process?

Will you get the 1st patch as is ?

For the other, have you a git tree available where all your patches lie?

> Sascha
> 
>>
>> They should need to be rebased on this new patch set as you made some changes
>> with the name of the structures and the name of the files. But before doing
>> this I would like to know if there was a chance that they will be applied in
>> barebox.
>>
>>
>>> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
>>> ---
>>>  arch/arm/mach-stm/imx_lcd_clk.c |    3 ++-
>>>  1 files changed, 2 insertions(+), 1 deletions(-)
>>>
>>> diff --git a/arch/arm/mach-stm/imx_lcd_clk.c b/arch/arm/mach-stm/imx_lcd_clk.c
>>> index 8938664..65bfc6e 100644
>>> --- a/arch/arm/mach-stm/imx_lcd_clk.c
>>> +++ b/arch/arm/mach-stm/imx_lcd_clk.c
>>> @@ -120,7 +120,8 @@ unsigned imx_set_lcdifclk(unsigned nc)
>>>  			best_frac, best_div, 480 * 18 / best_frac,
>>>  			480000 * 18 / best_frac / best_div);
>>>  
>>> -	reg = readl(IMX_CCM_BASE + HW_CLKCTRL_FRAC) & ~MASK_PIXFRAC;
>>> +	reg = readl(IMX_CCM_BASE + HW_CLKCTRL_FRAC);
>>> +	reg &= ~SET_PIXFRAC(MASK_PIXFRAC);
>>>  	reg |= SET_PIXFRAC(best_frac);
>>>  	writel(reg, IMX_CCM_BASE + HW_CLKCTRL_FRAC);
>>>  	writel(reg & ~CLKCTRL_FRAC_CLKGATEPIX, IMX_CCM_BASE + HW_CLKCTRL_FRAC);
>>
>>
>> -- 
>> Gregory Clement, Free Electrons
>> Kernel, drivers, real-time and embedded Linux
>> development, consulting, training and support.
>> http://free-electrons.com
>> +33 602 196 044
>>
> 

-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
+33 602 196 044

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