[U-Boot] [PATCH v2 05/14] mx51: Fix USB PHY clocks

Benoît Thébaudeau benoit.thebaudeau at advansee.com
Fri Sep 28 15:00:36 CEST 2012


Hi Stefano,

On Friday, September 28, 2012 12:43:53 PM, Stefano Babic wrote:
> On 28/09/2012 12:27, Benoît Thébaudeau wrote:
> > Hi Igor,
> > 
> > On Friday, September 28, 2012 9:26:38 AM, Igor Grinberg wrote:
> >> Hi Benoît,
> >>
> >> please, see a minor #ifdef comment below
> >>
> >> On 09/27/12 22:21, Benoît Thébaudeau wrote:
> >>> The i.MX51 has a single USB PHY clock, while the i.MX53 has two.
> >>> These 3 clocks
> >>> have different clock gate control bit-fields.
> >>>
> >>> The existing code was correct only for i.MX53, so this patch
> >>> fixes
> >>> the i.MX51
> >>> use case.
> >>>
> >>> Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau at advansee.com>
> >>> Cc: Stefano Babic <sbabic at denx.de>
> >>> Cc: Marek Vasut <marex at denx.de>
> >>> Cc: Jana Rapava <fermata7 at gmail.com>
> >>> Cc: Wolfgang Grandegger <wg at denx.de>
> >>> Cc: Igor Grinberg <grinberg at compulab.co.il>
> >>> ---
> >>> This patch supersedes http://patchwork.ozlabs.org/patch/177403/ .
> >>> Changes for v2:
> >>>  - Split patch into 3 parts (the 3, 4 and 5 from this v2 series).
> >>>  - Merge the various set_usb_phy*_clk() functions (they were
> >>>  identical).
> >>>
> >>>  .../arch/arm/cpu/armv7/mx5/clock.c                 |   20
> >>>  +++++++++++++-------
> >>>  .../arch/arm/include/asm/arch-mx5/clock.h          |    7
> >>>  ++++++-
> >>>  .../drivers/usb/host/ehci-mx5.c                    |    6 +++++-
> >>>  3 files changed, 24 insertions(+), 9 deletions(-)
> >>>
> >>> diff --git u-boot-imx-e1eb75b.orig/arch/arm/cpu/armv7/mx5/clock.c
> >>> u-boot-imx-e1eb75b/arch/arm/cpu/armv7/mx5/clock.c
> >>> index df7e5cd..f727cfa 100644
> >>> --- u-boot-imx-e1eb75b.orig/arch/arm/cpu/armv7/mx5/clock.c
> >>> +++ u-boot-imx-e1eb75b/arch/arm/cpu/armv7/mx5/clock.c
> >>> @@ -126,11 +126,21 @@ int enable_i2c_clk(unsigned char enable,
> >>> unsigned i2c_num)
> >>>  }
> >>>  #endif
> >>>  
> >>> -void set_usb_phy1_clk(void)
> >>> +void set_usb_phy_clk(void)
> >>>  {
> >>>  	clrbits_le32(&mxc_ccm->cscmr1, MXC_CCM_CSCMR1_USB_PHY_CLK_SEL);
> >>>  }
> >>>  
> >>> +#if defined(CONFIG_MX51)
> >>> +void enable_usb_phy_clk(unsigned char enable)
> >>
> >> I think the same name as the MX53 case will do better, see
> >> explanation below.
> >>
> >>> +{
> >>> +	unsigned int cg = enable ? MXC_CCM_CCGR_CG_ON :
> >>> MXC_CCM_CCGR_CG_OFF;
> >>> +
> >>> +	clrsetbits_le32(&mxc_ccm->CCGR2,
> >>> +			MXC_CCM_CCGR2_USB_PHY(MXC_CCM_CCGR_CG_MASK),
> >>> +			MXC_CCM_CCGR2_USB_PHY(cg));
> >>> +}
> >>
> >> I would add here (again explanation below):
> >> void enable_usb_phy2_clk(unsigned char enable)
> >> {
> >> 	/* MX51 has a single USB PHY clock, so do nothing here */
> >> }
> >>
> >>> +#elif defined(CONFIG_MX53)
> >>>  void enable_usb_phy1_clk(unsigned char enable)
> >>>  {
> >>>  	unsigned int cg = enable ? MXC_CCM_CCGR_CG_ON :
> >>>  	MXC_CCM_CCGR_CG_OFF;
> >>> @@ -140,11 +150,6 @@ void enable_usb_phy1_clk(unsigned char
> >>> enable)
> >>>  			MXC_CCM_CCGR4_USB_PHY1(cg));
> >>>  }
> >>>  
> >>> -void set_usb_phy2_clk(void)
> >>> -{
> >>> -	clrbits_le32(&mxc_ccm->cscmr1, MXC_CCM_CSCMR1_USB_PHY_CLK_SEL);
> >>> -}
> >>> -
> >>>  void enable_usb_phy2_clk(unsigned char enable)
> >>>  {
> >>>  	unsigned int cg = enable ? MXC_CCM_CCGR_CG_ON :
> >>>  	MXC_CCM_CCGR_CG_OFF;
> >>> @@ -153,6 +158,7 @@ void enable_usb_phy2_clk(unsigned char
> >>> enable)
> >>>  			MXC_CCM_CCGR4_USB_PHY2(MXC_CCM_CCGR_CG_MASK),
> >>>  			MXC_CCM_CCGR4_USB_PHY2(cg));
> >>>  }
> >>> +#endif
> >>>  
> >>>  /*
> >>>   * Calculate the frequency of PLLn.
> >>> @@ -803,7 +809,7 @@ void mxc_set_sata_internal_clock(void)
> >>>  	u32 *tmp_base =
> >>>  		(u32 *)(IIM_BASE_ADDR + 0x180c);
> >>>  
> >>> -	set_usb_phy1_clk();
> >>> +	set_usb_phy_clk();
> >>>  
> >>>  	clrsetbits_le32(tmp_base, 0x6, 0x4);
> >>>  }
> >>> diff --git
> >>> u-boot-imx-e1eb75b.orig/arch/arm/include/asm/arch-mx5/clock.h
> >>> u-boot-imx-e1eb75b/arch/arm/include/asm/arch-mx5/clock.h
> >>> index 55e3b51..e4ca417 100644
> >>> --- u-boot-imx-e1eb75b.orig/arch/arm/include/asm/arch-mx5/clock.h
> >>> +++ u-boot-imx-e1eb75b/arch/arm/include/asm/arch-mx5/clock.h
> >>> @@ -56,8 +56,13 @@ u32 imx_get_uartclk(void);
> >>>  u32 imx_get_fecclk(void);
> >>>  unsigned int mxc_get_clock(enum mxc_clock clk);
> >>>  int mxc_set_clock(u32 ref, u32 freq, u32 clk_type);
> >>> -void set_usb_phy2_clk(void);
> >>> +void set_usb_phy_clk(void);
> >>> +#if defined(CONFIG_MX51)
> >>> +void enable_usb_phy_clk(unsigned char enable);
> >>> +#elif defined(CONFIG_MX53)
> >>> +void enable_usb_phy1_clk(unsigned char enable);
> >>>  void enable_usb_phy2_clk(unsigned char enable);
> >>> +#endif
> >>
> >> If you follow my suggestion above, then here you will only have:
> >>  -void set_usb_phy2_clk(void);
> >>  +void set_usb_phy_clk(void);
> >>  +void enable_usb_phy1_clk(unsigned char enable);
> >>
> >> and no complicating with #ifdefs needed.
> >>
> >>>  void set_usboh3_clk(void);
> >>>  void enable_usboh3_clk(unsigned char enable);
> >>>  void mxc_set_sata_internal_clock(void);
> >>> diff --git u-boot-imx-e1eb75b.orig/drivers/usb/host/ehci-mx5.c
> >>> u-boot-imx-e1eb75b/drivers/usb/host/ehci-mx5.c
> >>> index 58cdcbe..5bf89f0 100644
> >>> --- u-boot-imx-e1eb75b.orig/drivers/usb/host/ehci-mx5.c
> >>> +++ u-boot-imx-e1eb75b/drivers/usb/host/ehci-mx5.c
> >>> @@ -221,8 +221,12 @@ int ehci_hcd_init(void)
> >>>  
> >>>  	set_usboh3_clk();
> >>>  	enable_usboh3_clk(1);
> >>> -	set_usb_phy2_clk();
> >>> +	set_usb_phy_clk();
> >>> +#if defined(CONFIG_MX51) && CONFIG_MXC_USB_PORT == 0
> >>> +	enable_usb_phy_clk(1);
> >>> +#elif defined(CONFIG_MX53)
> >>>  	enable_usb_phy2_clk(1);
> >>> +#endif
> >>
> >> same here, it should be much cleaner.
> >>
> >>>  	mdelay(1);
> >>>  
> >>>  	/* Do board specific initialization */
> >>>
> > 
> > Indeed. In clock.h, the #ifdefs could anyway be removed with the
> > naming from my patch. The only difference would be an error at
> > link time rather than at compile time if these functions were
> > called for the wrong i.MX5. If we change the naming as you
> > suggest, it's not a problem for set_usb_phy1_clk(), but for
> > enable_usb_phy2_clk() I think that it would not really make sense.
> > My point is that ehci-mx5.c should be cleaned even more deeply in
> > order to initialize the USB PHYs corresponding to the selected
> > EHCI ports, and not all (or only some for i.MX53) the PHYs at the
> > beginning of ehci_hcd_init(). Also, calling enable_usb_phy2_clk()
> > for i.MX51 would not make sense, even if it does nothing, because
> > it would be confusing. So this solution has both advantages and
> > drawbacks.
> > 
> > Stefano, Marek, what do you think?
> 
> I am much sensible regarding #ifdef. I admit, I hate them. Igor's
> suggestion drop some of them, and IMHO the code is more readable,
> independently if and when the ehci-mx5.c will be cleaned up. However,
> I
> understand it is a personal taste ;-)

OK, so should I eventually send for that an update only of this specific patch
(not the full series), or will it just be fine with the current v2?

Best regards,
Benoît


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