From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Vasut Subject: Re: [PATCH v2 1/5] mtd: spi-nor: notify (Q)SPI controller about protocol change Date: Thu, 23 Jul 2015 09:00:50 +0200 Message-ID: <201507230900.50570.marex@denx.de> References: <201507221541.46135.marex@denx.de> <55AFC3F0.5050002@atmel.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <55AFC3F0.5050002-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org> Sender: linux-spi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Cyrille Pitchen Cc: nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org, broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, computersforpeace-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, zajec5-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, beanhuo-AL4WhLSQfzjQT0dZR+AlfA@public.gmane.org, juhosg-p3rKhJxN3npAfugRpC6u6w@public.gmane.org, shijie.huang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, ben-/+tVBieCtBitmTQ+vhA3Yw@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, pawel.moll-5wv7dgnIgG8@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg@public.gmane.org, galak-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, linux-mtd-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: devicetree@vger.kernel.org On Wednesday, July 22, 2015 at 06:25:20 PM, Cyrille Pitchen wrote: > Hi Marek, >=20 > Le 22/07/2015 15:41, Marek Vasut a =E9crit : > > On Wednesday, July 22, 2015 at 03:17:06 PM, Cyrille Pitchen wrote: > >> Once the Quad SPI mode has been enabled on a Micron flash memory, = this > >> device expects ALL the following commands to use the SPI 4-4-4 pro= tocol. > >> The (Q)SPI controller needs to be notified about the protocol chan= ge so > >> it can adapt and keep on dialoging with the Micron memory. > >>=20 > >> Signed-off-by: Cyrille Pitchen > >> --- > >>=20 > >> drivers/mtd/spi-nor/spi-nor.c | 17 +++++++++++++++++ > >> include/linux/mtd/spi-nor.h | 13 +++++++++++++ > >> 2 files changed, 30 insertions(+) > >>=20 > >> diff --git a/drivers/mtd/spi-nor/spi-nor.c > >> b/drivers/mtd/spi-nor/spi-nor.c index d78831b4422b..93627d4e6be8 1= 00644 > >> --- a/drivers/mtd/spi-nor/spi-nor.c > >> +++ b/drivers/mtd/spi-nor/spi-nor.c > >> @@ -163,6 +163,18 @@ static inline int write_disable(struct spi_no= r > >> *nor) > >>=20 > >> return nor->write_reg(nor, SPINOR_OP_WRDI, NULL, 0, 0); > >> =20 > >> } > >>=20 > >> +/* > >> + * Notify the (Q)SPI controller about the new protocol to be used= =2E > >=20 > > Hi! > >=20 > > Can you please just reword this a little, so that it is absolutelly= clear > > even to the less bright of us (like me) that this is a notification > > coming from the upper layers (ie. the spi-nor framework) toward the > > hardware ? >=20 > Sure, no problem! what about the following? >=20 > /* > * Let the spi-nor framework notify lower layers, especially the driv= er of > the * (Q)SPI controller, about the new protocol to be used. Indeed, o= nce > the * spi-nor framework has sent manufacturer specific commands to a > memory to * enable its Quad SPI mode, it should immediately after tel= l the > QSPI * controller to use the very same Quad SPI protocol as expected = by > the memory. */ Sure, excellent, thanks ! :-) -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html