Re: [PATCHv4 2.6.34-rc4 5/7] mxc: Add generic USB HWinitializationfor MX51

[Sascha Hauer]

On Mon, Apr 19, 2010 at 08:40:29AM -0700, Nguyen Dinh-R00091 wrote:
>  
> 
> -----Original Message-----
> From: Sascha Hauer [mailto:s.hauer@xxxxxxxxxxxxxx] 
> Sent: Saturday, April 17, 2010 9:07 PM
> To: Nguyen Dinh-R00091
> Cc: linux-kernel@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx;
> linux@xxxxxxxxxxxxxxxx; valentin.longchamp@xxxxxxx; daniel@xxxxxxxx;
> grant.likely@xxxxxxxxxxxx; bryan.wu@xxxxxxxxxxxxx;
> amit.kucheria@xxxxxxxxxxxxx; Herring Robert-RA7055; Li Jun-R65092; Zhang
> Lily-R58066
> Subject: Re: [PATCHv4 2.6.34-rc4 5/7] mxc: Add generic USB
> HWinitialization for MX51
> 
> On Fri, Apr 16, 2010 at 02:16:09PM -0500, Dinh.Nguyen@xxxxxxxxxxxxx
> wrote:
> > From: Dinh Nguyen <Dinh.Nguyen@xxxxxxxxxxxxx>
> > 
> > This patch adds USB HW initializiation code to /plat-mxc/ehci.c.
> > 	-Stops and resets USB HW
> > 	-Sets some specific PHY settings
> > 	-Stop and restart the USB HW.
> > Renames mxc_set_usbcontrol to mxc_initialize_usb_hw.
> > 
> > This patch applies to 2.6.34-rc4.
> > 
> > Signed-off-by: Dinh Nguyen <Dinh.Nguyen@xxxxxxxxxxxxx>
> > ---
> >  arch/arm/plat-mxc/ehci.c                  |  128
> ++++++++++++++++++++++++++++-
> >  arch/arm/plat-mxc/include/mach/mxc_ehci.h |    2 +-
> >  2 files changed, 127 insertions(+), 3 deletions(-)
> > 
> > diff --git a/arch/arm/plat-mxc/ehci.c b/arch/arm/plat-mxc/ehci.c index
> 
> > cb0b638..35ff1c1 100644
> > --- a/arch/arm/plat-mxc/ehci.c
> > +++ b/arch/arm/plat-mxc/ehci.c
> > @@ -1,5 +1,6 @@
> >  /*
> >   * Copyright (c) 2009 Daniel Mack <daniel@xxxxxxxx>
> > + * Copyright (C) 2010 Freescale Semiconductor, Inc.
> >   *
> >   * This program is free software; you can redistribute it and/or
> modify it
> >   * under the terms of the GNU General Public License as published by 
> > the @@ -18,6 +19,7 @@
> >  
> >  #include <linux/platform_device.h>
> >  #include <linux/io.h>
> > +#include <linux/delay.h>
> >  
> >  #include <mach/hardware.h>
> >  #include <mach/mxc_ehci.h>
> > @@ -50,9 +52,14 @@
> >  #define MX35_H1_TLL_BIT		(1 << 5)
> >  #define MX35_H1_USBTE_BIT	(1 << 4)
> >  
> > -int mxc_set_usbcontrol(int port, unsigned int flags)
> > +int mxc_intialize_usb_hw(int port, unsigned int flags)
> >  {
> >  	unsigned int v;
> > +	void __iomem *usb_base;
> > +	u32 usbotg_base;
> > +	u32 usbother_base;
> > +	int timeout;
> > +	int ret = 0;
> >  #ifdef CONFIG_ARCH_MX3
> >  	if (cpu_is_mx31()) {
> >  		v = readl(MX31_IO_ADDRESS(MX31_OTG_BASE_ADDR + @@ -186,9
> +193,126 
> > @@ int mxc_set_usbcontrol(int port, unsigned int flags)
> >  		return 0;
> >  	}
> >  #endif /* CONFIG_MACH_MX27 */
> > +#ifdef CONFIG_ARCH_MX51
> > +	if (cpu_is_mx51()) {
> > +		usb_base = ioremap(MX51_OTG_BASE_ADDR, SZ_4K);
> > +
> > +		switch (port) {
> > +		case 0:	/* OTG port */
> > +			usbotg_base = (u32)usb_base + USBOTG_OFFSET;
> > +			break;
> > +		case 1:	/* Host 1 port */
> > +			usbotg_base = (u32)usb_base + USBH1_OFFSET;
> > +			break;
> > +		default:
> > +			printk(KERN_ERR"%s no such port %d\n", __func__,
> port);
> > +			ret = -ENOENT;
> > +			goto error;
> > +		}
> > +		usbother_base = (u32)usb_base + USBOTHER_REGS_OFFSET;
> > +
> > +		/* Stop then Reset */
> > +		v = __raw_readl(usbotg_base + USBCMD_OFFSET);
> > +		v &= ~UCMD_RUN_STOP;
> > +		__raw_writel(v, usbotg_base + USBCMD_OFFSET);
> > +		timeout = 0x100000;
> > +		while (--timeout && __raw_readl(usbotg_base +
> USBCMD_OFFSET) & UCMD_RUN_STOP)
> > +			cpu_relax();
> > +		if (!timeout) {
> > +			printk(KERN_ERR "%s could not stop usb
> hardware\n", __func__);
> > +			ret = -ETIMEDOUT;
> > +			goto error;
> > +		}
> > +
> > +		v = __raw_readl(usbotg_base + USBCMD_OFFSET);
> > +		v |= UCMD_RESET;
> > +		__raw_writel(v, usbotg_base + USBCMD_OFFSET);
> > +		timeout = 0x100000;
> > +		while (--timeout && __raw_readl(usbotg_base +
> USBCMD_OFFSET) & UCMD_RESET)
> > +			cpu_relax();
> > +		if (!timeout) {
> > +			printk(KERN_ERR "%s could not reset usb
> hardware\n", __func__);
> > +			ret = -ETIMEDOUT;
> > +			goto error;
> > +		}
> > +
> > +		switch (port) {
> > +		case 0:	/*OTG port */
> > +			v = __raw_readl(usbother_base +
> USB_PHY_CTR_FUNC_OFFSET);
> > +			v |= USB_UTMI_PHYCTRL_OC_DIS; /* OC is not used
> */
> > +			__raw_writel(v, usbother_base +
> USB_PHY_CTR_FUNC_OFFSET);
> > +
> > +			v = __raw_readl(usbother_base + USBCTRL_OFFSET);
> > +			v &= ~(UCTRL_OPM | UCTRL_OWIE);/* OTG
> wakeup/power mask disable */
> > +			__raw_writel(v, usbother_base + USBCTRL_OFFSET);
> > +
> > +			/* Set the PHY clock to 19.2MHz */
> > +			v = __raw_readl(usbother_base +
> USB_PHY_CTR_FUNC2_OFFSET);
> > +			v &= ~USB_UTMI_PHYCTRL2_PLLDIV_MASK;
> > +			v |= 0x01;
> > +			__raw_writel(v, usbother_base +
> USB_PHY_CTR_FUNC2_OFFSET);
> > +			break;
> 
> The sense of this funtion is to make the interface configuration,
> especially the receiver type configurable with the flags parameter to
> this function. This all looks very specific to your board, flags is
> completely unused.
> 
> [Dinh] I think you're right Sascha, I think I can move this to the board
> initialization. Do you agree Daniel?

No, and Daniel won't agree either. What I meant is that you should add
support for the different transceiver types in this function. Take
i.MX27/31/35 as an example how to do this: Parse the flag parameter and
do whatever you have to.

Sascha


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