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Message-ID: <CADB-GoKACxJCNqj3OsQdgmWoK3y-hgbiLoCBzA7kbcJ3rMoheA@mail.gmail.com>
Date: Thu, 21 Mar 2013 14:35:54 +0800
From: Yuan-Hsin Chen <yuanlmm@...il.com>
To: Alan Stern <stern@...land.harvard.edu>
Cc: Felipe Balbi <balbi@...com>, gregkh@...uxfoundation.org,
sarah.a.sharp@...ux.intel.com, Julia.Lawall@...6.fr,
linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org,
Yuan-Hsin Chen <yhchen@...aday-tech.com>,
john453@...aday-tech.com
Subject: Re: [PATCH] usb host: Faraday FUSBH200 HCD driver.
Hi,
On Wed, Mar 20, 2013 at 10:26 PM, Alan Stern <stern@...land.harvard.edu> wrote:
> On Wed, 20 Mar 2013, Yuan-Hsin Chen wrote:
>
>> Hi,
>>
>> On Tue, Mar 19, 2013 at 11:48 PM, Alan Stern <stern@...land.harvard.edu> wrote:
>> > On Tue, 19 Mar 2013, Yuan-Hsin Chen wrote:
>> >
>> >> > What about the port_status registers? They're not between command and
>> >> > async_next. If they aren't consistent with EHCI, it makes things a lot
>> >> > more complicated.
>> >>
>> >> fusbh200 has only one port_status register with different offset,
>> >> 0x30, and the position of some bits are different from EHCI.
>>
>> How about adding kernel configuration to adjust offset for FUSBH200 in
>> ehci_def.h? So port_status would be in offset 0x20 from ehci_regs.
>>
>> For example,
>>
>> /* ASYNCLISTADDR: offset 0x18 */
>> u32 async_next; /* address of next async queue head */
>>
>> #ifndef CONFIG_USB_EHCI_HCD_FUSBH200
>> u32 reserved1[2];
>>
>> /* TXFILLTUNING: offset 0x24 */
>> u32 txfill_tuning; /* TX FIFO Tuning register */
>> #define TXFIFO_DEFAULT (8<<16) /* FIFO burst threshold 8 */
>>
>> u32 reserved2[6];
>>
>> /* CONFIGFLAG: offset 0x40 */
>> u32 configured_flag;
>> #define FLAG_CF (1<<0) /* true: we'll support "high speed" */
>>
>> #else
>> u32 reserved1;
>> #endif
>> /* PORTSC: offset 0x44 */
>> u32 port_status[0]; /* up to N_PORTS */
>
> This is acceptable _only_ if it is not possible to use an FUSBH200
> controller in the same computer as a normal EHCI controller.
>
>> Furthermore, there are PORT_POWER, PORT_OWNER, PORT_LED_XXX,
>> PORT_TEST, PORT_WKCONN_E, PORT_WKDISC_E, PORT_WKOC_E absent in
>> port_status of FUSBH200. Also PORT_OC and PORT_OCC are in another
>> register. Is it ok to use quirk flag also?
>
> Yes, those can be handled by a quirk flag. Does the FUSBH200 have a
> built-in Transaction Translator?
Yes, the FUSBH200 has built-in Transaction Translator.
I will modify the driver based on what we discussed before and re-submit it.
Thank you for your time.
>
> Alan Stern
>
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