Subject: [PATCH 2/2] ARM: mach-imx: CAN clock fix for i.MX53

From: [email-masked] (Roland Stigge)
Date: Fri, 26 Oct 2012 11:16:20 +0200

Hi!

On 10/26/2012 10:59 AM, Sascha Hauer wrote:
> On Thu, Oct 25, 2012 at 01:26:40PM +0200, Roland Stigge wrote:
>> This patch fixes CAN clocking on i.MX53.
>>
>> Signed-off-by: Roland Stigge <[email-masked]>
>>
>> ---
>>  arch/arm/mach-imx/clk-imx51-imx53.c |    8 ++++----
>>  1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> --- linux-2.6.orig/arch/arm/mach-imx/clk-imx51-imx53.c
>> +++ linux-2.6/arch/arm/mach-imx/clk-imx51-imx53.c
>> @@ -426,10 +426,10 @@ int __init mx53_clocks_init(unsigned lon
>>  	clk[usb_phy2_gate] = imx_clk_gate2("usb_phy2_gate", "usb_phy_sel", MXC_CCM_CCGR4, 12);
>>  	clk[can_sel] = imx_clk_mux("can_sel", MXC_CCM_CSCMR2, 6, 2,
>>  				mx53_can_sel, ARRAY_SIZE(mx53_can_sel));
>> -	clk[can1_serial_gate] = imx_clk_gate2("can1_serial_gate", "can_sel", MXC_CCM_CCGR6, 22);
>> -	clk[can1_ipg_gate] = imx_clk_gate2("can1_ipg_gate", "ipg", MXC_CCM_CCGR6, 20);
>> -	clk[can2_serial_gate] = imx_clk_gate2("can2_serial_gate", "can_sel", MXC_CCM_CCGR4, 8);
>> -	clk[can2_ipg_gate] = imx_clk_gate2("can2_ipg_gate", "ipg", MXC_CCM_CCGR4, 6);
> 
> I just rechecked. The above matches the i.MX53 Reference Manual rev 2.1
> 
>> +	clk[can1_serial_gate] = imx_clk_gate2("can1_serial_gate", "can_sel", MXC_CCM_CCGR4, 6);
>> +	clk[can1_ipg_gate] = imx_clk_gate2("can1_ipg_gate", "ipg", MXC_CCM_CCGR4, 8);
>> +	clk[can2_serial_gate] = imx_clk_gate2("can2_serial_gate", "can_sel", MXC_CCM_CCGR4, 6);
>> +	clk[can2_ipg_gate] = imx_clk_gate2("can2_ipg_gate", "ipg", MXC_CCM_CCGR4, 8);
> 
> This doesn't.

This may be right, but unfortunately, since the introduction of your
can1 + can2 clocking change, the first block stopped working for me.

My above patch is basically a rollback which works for the first block.

An interesting hint is: can2 (which was the only one defined _before_
your can1 + can2 change) didn't work before and afterwards at all. (But
I'm not using it anyway.)

Thanks,

Roland