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

From: [email-masked] (Marc Kleine-Budde)
Date: Fri, 26 Oct 2012 12:30:52 +0200

On 10/26/2012 11:16 AM, Roland Stigge wrote:
> 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

An old rev 1 manual has lists the same bits.

>>> +	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.

You are effectively using can2's clock for can1. Are you sure you
haven't mixed up can1 and can2?

> 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.)

Marc

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
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