From: tony@atomide.com (Tony Lindgren)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC 1/2] ARM: OMAP2+: AM33XX: I2C Sleep/wake sequence support
Date: Wed, 1 May 2013 16:26:49 -0700 [thread overview]
Message-ID: <20130501232649.GN28721@atomide.com> (raw)
In-Reply-To: <1367434947-6442-2-git-send-email-Russ.Dill@ti.com>
* Russ Dill <Russ.Dill@ti.com> [130501 12:07]:
> This patch adds the ability to write an I2C sleep sequence from
> SRAM just before WFI, and a wake sequence just after control is passed
> from the M3. This is useful for adjusting voltages during sleep that cannot
> be lowered while SDRAM is active.
>
> Each sequence is a series of I2C transfers in the form:
>
> u8 length | u8 chip address | u8 byte0/reg address | u8 byte 1 | u8 byte n ...
>
> The length indicates the number of bytes to transfer, including the register
> address. The length of the sequence is limited by the amount of space
> reserved in SRAM, 127 bytes.
>
> The sequences are taken from the i2c1 node in the device tree. The property
> name for the sleep sequence is "sleep_sequence" and the property name for
> the wake sequence is "wake_sequence". Each property should be an array of
> bytes.
>
> No actions are performed if the properties are not present in the device
> tree.
Looks like you should make that into just a regular device driver that lives
under drivers/ somewhere?
Regards,
Tony
next prev parent reply other threads:[~2013-05-01 23:26 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-01 19:02 [RFC 0/2] am33xx 0.950V core sleep mode Russ Dill
[not found] ` <1367434947-6442-2-git-send-email-Russ.Dill@ti.com>
2013-05-01 23:26 ` Tony Lindgren [this message]
2013-05-01 23:37 ` [RFC 1/2] ARM: OMAP2+: AM33XX: I2C Sleep/wake sequence support Russ Dill
2013-05-01 23:54 ` Tony Lindgren
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