From: Bill Gatliff <bgat@billgatliff•com>
To: linuxppc-dev@ozlabs•org
Subject: Sleep-capable GPIO slave-selects on MPC52xx?
Date: Mon, 11 Jan 2010 14:13:31 -0600 [thread overview]
Message-ID: <4B4B866B.10207@billgatliff.com> (raw)
Guys:
A platform I have inherited utilizes a GPIO on an I2C expander chip
(MAX7314) as a SPI slave-select. I'm using the actual MPC52xx SPI
peripheral, not a PSC.
It looks like the current version of the MPC52xx SPI driver won't work
with sleep-capable GPIOs for slave-selects. In particular, it looks
like mpc52xx_spi_fsmstate_transfer() is an interrupt handler that calls
mpc52xx_spi_chipsel(), which itself calls gpio_set_value(). Or, at
least my kernel thinks so, since I get a barrage of oops-type output
screaming at me whenever I hit the SPI device. :)
Am I missing something, or is this a known (or at least now-identified)
limitation of the current mpc52xx_spi.c?
Thanks!
b.g.
--
Bill Gatliff
Embedded systems training and consulting
http://billgatliff.com
bgat@billgatliff•com
next reply other threads:[~2010-01-11 20:13 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-11 20:13 Bill Gatliff [this message]
2010-01-12 16:50 ` Sleep-capable GPIO slave-selects on MPC52xx? Bill Gatliff
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