From: Martin Guy <martinwguy-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
To: Mika Westerberg <mika.westerberg-X3B1VOXEql0@public.gmane.org>
Cc: "spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org"
<spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org>,
"linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org"
<linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org>
Subject: Re: [PATCH v3 0/2] spi: driver for Cirrus EP93xx SPI controller
Date: Sat, 17 Apr 2010 19:43:23 +0100 [thread overview]
Message-ID: <s2i56d259a01004171143m74b06d85yd1cbb38ef7ce778e@mail.gmail.com> (raw)
In-Reply-To: <20100417045913.GA19534-WfG2TfFPcQ9S6P4I59wummXnswh1EIUO@public.gmane.org>
(sorry for the duplicate, Mika, I forgot to include the list)
On 4/17/10, Mika Westerberg <mika.westerberg-X3B1VOXEql0@public.gmane.org> wrote:
> However, I'm not sure what you mean by limited only to built-in GPIOs? Currently
> the driver does:
>
> info->cs_control(spi->chip_select, value, info->data);
>
> when it wants to assert/deassert the chip select.
There's a further strangeness when a board has a single SPI device not
using any GPIO chip select. At present, clients seem to need to
declare that they have 1 chip select and to provide an empty
cs_control function that does nothing. For example:
static void null_cs_control(unsigned cs, unsigned value, void *data) {
/* Sim.One only has MMC card and no GPIO chip select logic */
}
static struct ep93xx_spi_info simone_spi_info = {
.num_chipselect = 1,
.cs_control = null_cs_control,
.data = NULL,
};
...
static void __init simone_init_machine(void)
{
...
spi_register_board_info(simone_spi_board_info,
ARRAY_SIZE(simone_spi_board_info));
ep93xx_register_spi(&simone_spi_info);
...
Allowing cs_control to be NULL would do away with the empty function, but
when I just tried with num_chipselect = 0 the device did not appear. There
may be a better solution.
M
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next prev parent reply other threads:[~2010-04-17 18:43 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-13 14:10 [PATCH v3 0/2] spi: driver for Cirrus EP93xx SPI controller Mika Westerberg
[not found] ` <cover.1271156934.git.mika.westerberg-X3B1VOXEql0@public.gmane.org>
2010-04-13 14:10 ` [PATCH v3 1/2] spi: implemented " Mika Westerberg
2010-04-17 6:30 ` Grant Likely
2010-04-17 11:00 ` Mika Westerberg
2010-04-19 18:02 ` Grant Likely
[not found] ` <q2pfa686aa41004191102qc93f09b6m941785b4cb4e32db-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2010-04-19 18:52 ` Martin Guy
[not found] ` <o2g56d259a01004191152w9c2245fdgaa2d4ac1b9e95ed7-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2010-04-19 19:05 ` Grant Likely
[not found] ` <j2hfa686aa41004191205jf61e53ectc994ab0e5a2c4c53-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2010-04-19 19:26 ` Martin Guy
2010-04-19 19:16 ` Martin Guy
2010-05-20 4:56 ` Grant Likely
2010-04-20 6:16 ` Mika Westerberg
[not found] ` <e0e5dc30af89f0b65fd2e5e52f9e7fe9f162516b.1271156934.git.mika.westerberg-X3B1VOXEql0@public.gmane.org>
2010-04-13 14:10 ` [PATCH v3 2/2] ep93xx: SPI driver platform support code Mika Westerberg
[not found] ` <d24cf3f10fb125837c9b660b3880956940440b79.1271156934.git.mika.westerberg-X3B1VOXEql0@public.gmane.org>
2010-04-16 18:40 ` H Hartley Sweeten
2010-04-16 18:28 ` [PATCH v3 0/2] spi: driver for Cirrus EP93xx SPI controller H Hartley Sweeten
[not found] ` <0D753D10438DA54287A00B0270842697636D710785-gaq956PjLg32KbjnnMDalRurcAul1UnsRrxOEX5GOmysTnJN9+BGXg@public.gmane.org>
2010-04-17 4:59 ` Mika Westerberg
[not found] ` <20100417045913.GA19534-WfG2TfFPcQ9S6P4I59wummXnswh1EIUO@public.gmane.org>
2010-04-17 18:43 ` Martin Guy [this message]
[not found] ` <s2i56d259a01004171143m74b06d85yd1cbb38ef7ce778e-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2010-04-18 5:33 ` Mika Westerberg
2010-04-19 17:04 ` H Hartley Sweeten
[not found] ` <0D753D10438DA54287A00B0270842697636D78D9CF-gaq956PjLg32KbjnnMDalRurcAul1UnsRrxOEX5GOmysTnJN9+BGXg@public.gmane.org>
2010-04-19 17:44 ` Mika Westerberg
[not found] ` <20100419174446.GH19534-WfG2TfFPcQ9S6P4I59wummXnswh1EIUO@public.gmane.org>
2010-04-19 18:11 ` H Hartley Sweeten
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