From: Boris Brezillon <boris.brezillon@bootlin.com>
To: Janusz Krzysztofik <jmkrzyszt@gmail.com>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>,
Richard Weinberger <richard@nod.at>,
David Woodhouse <dwmw2@infradead.org>,
Brian Norris <computersforpeace@gmail.com>,
Marek Vasut <marek.vasut@gmail.com>,
Tony Lindgren <tony@atomide.com>,
Aaro Koskinen <aaro.koskinen@iki.fi>,
Linus Walleij <linus.walleij@linaro.org>,
linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org,
linux-mtd@lists.infradead.org, linux-gpio@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 5/7] mtd: rawnand: ams-delta: Set port direction when needed
Date: Thu, 16 Aug 2018 09:30:52 +0200 [thread overview]
Message-ID: <20180816093052.2bcbf004@bbrezillon> (raw)
In-Reply-To: <20180813223448.21316-6-jmkrzyszt@gmail.com>
On Tue, 14 Aug 2018 00:34:46 +0200
Janusz Krzysztofik <jmkrzyszt@gmail.com> wrote:
> In its current shape, the driver sets data port direction before each
> byte read/write operation, even during multi-byte transfers. Improve
> performance of the driver by setting the port direction only when
> needed.
>
> This optimisation will become particularly important as soon as
> planned conversion of the driver to GPIO API for data I/O will be
> implemented.
>
> Signed-off-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>
> ---
> drivers/mtd/nand/raw/ams-delta.c | 59 ++++++++++++++++++++++++++++++++--------
> 1 file changed, 47 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/mtd/nand/raw/ams-delta.c b/drivers/mtd/nand/raw/ams-delta.c
> index 09d6901fc94d..5f9180fe4f8b 100644
> --- a/drivers/mtd/nand/raw/ams-delta.c
> +++ b/drivers/mtd/nand/raw/ams-delta.c
> @@ -45,6 +45,7 @@ struct ams_delta_nand {
> struct gpio_desc *gpiod_ale;
> struct gpio_desc *gpiod_cle;
> void __iomem *io_base;
> + bool data_in;
> };
>
> /*
> @@ -72,50 +73,83 @@ static const struct mtd_partition partition_info[] = {
> .size = 3 * SZ_256K },
> };
>
> -static void ams_delta_write_byte(struct mtd_info *mtd, u_char byte)
> +static void ams_delta_write_next_byte(struct mtd_info *mtd, u_char byte)
> {
> struct nand_chip *this = mtd_to_nand(mtd);
> struct ams_delta_nand *priv = nand_get_controller_data(this);
> - void __iomem *io_base = priv->io_base;
>
> - writew(0, io_base + OMAP_MPUIO_IO_CNTL);
> writew(byte, this->IO_ADDR_W);
> +
> gpiod_set_value(priv->gpiod_nwe, 0);
> ndelay(40);
> gpiod_set_value(priv->gpiod_nwe, 1);
> }
>
> -static u_char ams_delta_read_byte(struct mtd_info *mtd)
> +static void ams_delta_write_byte(struct mtd_info *mtd, u_char byte)
> {
> - u_char res;
> struct nand_chip *this = mtd_to_nand(mtd);
> struct ams_delta_nand *priv = nand_get_controller_data(this);
> void __iomem *io_base = priv->io_base;
>
> + if (priv->data_in) {
> + writew(0, io_base + OMAP_MPUIO_IO_CNTL);
> + priv->data_in = false;
> + }
> +
> + ams_delta_write_next_byte(mtd, byte);
> +}
I'm not a big fan of this {read,write}_byte/next_byte() approach.
Can't we do something like:
static void ams_delta_io_write(struct ams_delta_nand *priv, u8 data)
{
writew(byte, priv->nand_chip.IO_ADDR_W);
gpiod_set_value(priv->gpiod_nwe, 0);
ndelay(40);
gpiod_set_value(priv->gpiod_nwe, 1);
}
static u8 ams_delta_io_read(struct ams_delta_nand *priv)
{
u8 res;
gpiod_set_value(priv->gpiod_nre, 0);
ndelay(40);
res = readw(priv->nand_chip.IO_ADDR_R);
gpiod_set_value(priv->gpiod_nre, 1);
return res;
}
static void ams_delta_set_io_dir(struct ams_delta_nand *priv, bool in)
{
if (in == priv->data_in)
return;
writew(in ? ~0 : 0, priv->io_base + OMAP_MPUIO_IO_CNTL);
priv->data_in = in;
}
static void ams_delta_write_buf(struct mtd_info *mtd, const u8 *buf,
int len)
{
struct nand_chip *this = mtd_to_nand(mtd);
struct ams_delta_nand *priv = nand_get_controller_data(this);
int i;
ams_delta_set_io_dir(priv, false);
for (i =0; i < len; i++)
ams_delta_io_write(priv, buf[i]);
}
static void ams_delta_write_byte(struct mtd_info *mtd, u8 byte)
{
ams_delta_write_buf(mtd, &byte, 1);
}
static void ams_delta_read_buf(struct mtd_info *mtd, u8 *buf, int len)
{
struct nand_chip *this = mtd_to_nand(mtd);
struct ams_delta_nand *priv = nand_get_controller_data(this);
int i;
ams_delta_set_io_dir(priv, true);
for (i = 0; i < len; i++)
buf[i] = ams_delta_io_read(priv);
}
static u8 ams_delta_read_byte(struct mtd_info *mtd)
{
u8 res;
ams_delta_read_buf(mtd, &res, 1);
return res;
}
next prev parent reply other threads:[~2018-08-16 7:30 UTC|newest]
Thread overview: 93+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-18 23:57 [RFC PATCH 0/8] mtd: rawnand: ams-delta: Use gpio-omap accessors for data I/O Janusz Krzysztofik
2018-07-18 23:57 ` [RFC PATCH 1/8] mtd: rawnand: ams-delta: Use private structure Janusz Krzysztofik
2018-07-19 6:17 ` Boris Brezillon
2018-07-20 17:57 ` Janusz Krzysztofik
2018-07-18 23:57 ` [RFC PATCH 2/8] mtd: rawnand: ams-delta: Write protect device during probe Janusz Krzysztofik
2018-07-19 6:22 ` Boris Brezillon
2018-07-20 18:02 ` Janusz Krzysztofik
2018-07-18 23:57 ` [RFC PATCH 3/8] mtd: rawnand: ams-delta: Set port direction once per transfer Janusz Krzysztofik
2018-07-19 6:23 ` Boris Brezillon
2018-07-20 18:12 ` Janusz Krzysztofik
2018-07-20 19:29 ` Boris Brezillon
2018-07-18 23:57 ` [RFC PATCH 4/8] mtd: rawnand: ams-delta: Optimize pointer resolution on read/write Janusz Krzysztofik
2018-07-19 6:25 ` Boris Brezillon
2018-07-20 18:14 ` Janusz Krzysztofik
2018-07-20 19:29 ` Boris Brezillon
2018-07-18 23:57 ` [RFC PATCH 5/8] mtd: rawnand: ams-delta: Request data port GPIO resource Janusz Krzysztofik
2018-07-19 6:28 ` Boris Brezillon
2018-07-18 23:57 ` [RFC PATCH 6/8] gpio: omap: Add get/set_multiple() callbacks Janusz Krzysztofik
2018-07-29 20:29 ` Linus Walleij
2018-08-03 1:52 ` Grygorii Strashko
2018-08-03 16:47 ` Linus Walleij
2018-07-18 23:57 ` [RFC PATCH 7/8] mtd: rawnand: ams-delta: Check sanity of data GPIO resource Janusz Krzysztofik
2018-07-19 6:44 ` Boris Brezillon
2018-07-29 20:36 ` Linus Walleij
2018-07-29 21:16 ` Boris Brezillon
2018-07-29 20:33 ` Linus Walleij
2018-07-18 23:57 ` [RFC PATCH 8/8] mtd: rawnand: ams-delta: Use GPIO callbacks for data I/O Janusz Krzysztofik
2018-07-19 6:47 ` Boris Brezillon
2018-07-20 18:38 ` Janusz Krzysztofik
2018-07-20 19:48 ` Boris Brezillon
2018-07-19 6:15 ` [RFC PATCH 0/8] mtd: rawnand: ams-delta: Use gpio-omap accessors " Boris Brezillon
2018-07-20 17:55 ` Janusz Krzysztofik
2018-07-20 19:25 ` Boris Brezillon
2018-08-06 22:29 ` [RFC PATCH v2] mtd: rawnand: ams-delta: Use GPIO API " Janusz Krzysztofik
2018-08-06 22:29 ` [RFC PATCH v2 01/12] mtd: rawnand: ams-delta: Assign mtd->dev.parent, not mtd->owner Janusz Krzysztofik
2018-08-06 23:54 ` Marek Vasut
2018-08-07 21:55 ` Janusz Krzysztofik
2018-08-07 16:57 ` Boris Brezillon
2018-08-06 22:29 ` [RFC PATCH v2 02/12] mtd: rawnand: ams-delta: Use private structure Janusz Krzysztofik
2018-08-07 16:59 ` Boris Brezillon
2018-08-06 22:29 ` [RFC PATCH v2 03/12] ARM: OMAP1: ams-delta: Provide GPIO lookup table for NAND data port Janusz Krzysztofik
2018-08-07 16:59 ` Boris Brezillon
2018-08-10 10:10 ` Linus Walleij
2018-08-06 22:29 ` [RFC PATCH v2 04/12] mtd: rawnand: ams-delta: request data port GPIO resource Janusz Krzysztofik
2018-08-07 17:00 ` Boris Brezillon
2018-08-10 10:11 ` Linus Walleij
2018-08-06 22:29 ` [RFC PATCH v2 05/12] mtd: rawnand: ams-delta: use GPIO API for data read/write Janusz Krzysztofik
2018-08-06 23:57 ` Marek Vasut
2018-08-07 17:06 ` Boris Brezillon
2018-08-07 17:11 ` Janusz Krzysztofik
2018-08-10 10:25 ` Linus Walleij
2018-08-06 22:29 ` [RFC PATCH v2 06/12] ARM: OMAP1: ams-delta: drop obsolete NAND resources Janusz Krzysztofik
2018-08-06 22:29 ` [RFC PATCH v2 07/12] mtd: rawnand: ams-delta: Set port direction once per transfer Janusz Krzysztofik
2018-08-07 18:57 ` Boris Brezillon
2018-08-08 16:55 ` Janusz Krzysztofik
2018-08-08 17:42 ` Miquel Raynal
2018-08-06 22:29 ` [RFC PATCH v2 08/12] mtd: rawnand: ams-delta: Simplify pointer resolution on read/write Janusz Krzysztofik
2018-08-07 17:02 ` Boris Brezillon
2018-08-07 17:15 ` Janusz Krzysztofik
2018-08-06 22:29 ` [RFC PATCH v2 09/12] gpiolib: Identify GPIO descriptor arrays with direct mapping Janusz Krzysztofik
2018-08-06 23:29 ` Linus Walleij
2018-08-07 16:50 ` Janusz Krzysztofik
2018-08-07 17:10 ` Boris Brezillon
2018-08-07 17:14 ` Boris Brezillon
2018-08-07 17:19 ` Janusz Krzysztofik
2018-08-06 22:29 ` [RFC PATCH v2 10/12] gpiolib: Introduce bitmap get/set array API extension Janusz Krzysztofik
2018-08-06 22:29 ` [RFC PATCH v2 11/12] mtd: rawnand: ams-delta: Use GPIO API bitmap extension Janusz Krzysztofik
2018-08-06 22:29 ` [RFC PATCH v2 12/12] gpiolib: Add fast processing path to bitmap API functions Janusz Krzysztofik
2018-08-06 23:43 ` Linus Walleij
2018-08-07 17:29 ` Janusz Krzysztofik
2018-08-07 17:47 ` Boris Brezillon
2018-08-10 10:55 ` Linus Walleij
2018-08-13 22:34 ` [PATCH v3 0/7] mtd: rawnand: ams-delta: Use GPIO API for data I/O Janusz Krzysztofik
2018-08-13 22:34 ` [PATCH v3 1/7] mtd: rawnand: ams-delta: show parent device in sysfs Janusz Krzysztofik
2018-08-13 22:34 ` [PATCH v3 2/7] mtd: rawnand: ams-delta: Use private structure Janusz Krzysztofik
2018-08-13 22:34 ` [PATCH v3 3/7] ARM: OMAP1: ams-delta: Provide GPIO lookup table for NAND data port Janusz Krzysztofik
2018-08-13 22:34 ` [PATCH v3 4/7] mtd: rawnand: ams-delta: request data port GPIO resource Janusz Krzysztofik
2018-08-13 22:34 ` [PATCH v3 5/7] mtd: rawnand: ams-delta: Set port direction when needed Janusz Krzysztofik
2018-08-16 7:30 ` Boris Brezillon [this message]
2018-08-13 22:34 ` [PATCH v3 6/7] mtd: rawnand: ams-delta: Simplify pointer resolution on read/write Janusz Krzysztofik
2018-08-13 22:34 ` [PATCH v3 7/7] mtd: rawnand: ams-delta: use GPIO API for data I/O Janusz Krzysztofik
2018-08-16 7:39 ` Boris Brezillon
2018-11-21 11:08 ` Subject: [PATCH v4 0/4] mtd: rawnand: ams-delta: Use " Janusz Krzysztofik
2018-11-21 11:08 ` [PATCH v4 1/4] ARM: OMAP1: ams-delta: Provide GPIO lookup table for NAND data port Janusz Krzysztofik
2018-11-23 17:02 ` Tony Lindgren
2018-11-21 11:08 ` [PATCH v4 2/4] mtd: rawnand: ams-delta: Request data port GPIO resource Janusz Krzysztofik
2018-11-21 11:08 ` [PATCH v4 3/4] mtd: rawnand: ams-delta: Use GPIO API for data I/O Janusz Krzysztofik
2018-11-21 14:53 ` Boris Brezillon
2018-11-21 11:08 ` [PATCH v4 4/4] ARM: OMAP1: ams-delta: Drop obsolete NAND resources Janusz Krzysztofik
2018-11-21 14:56 ` Subject: [PATCH v4 0/4] mtd: rawnand: ams-delta: Use GPIO API for data I/O Boris Brezillon
2018-11-23 17:03 ` Tony Lindgren
2018-12-07 8:04 ` Miquel Raynal
2018-12-07 16:10 ` Tony Lindgren
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180816093052.2bcbf004@bbrezillon \
--to=boris.brezillon@bootlin.com \
--cc=aaro.koskinen@iki.fi \
--cc=computersforpeace@gmail.com \
--cc=dwmw2@infradead.org \
--cc=jmkrzyszt@gmail.com \
--cc=linus.walleij@linaro.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-gpio@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mtd@lists.infradead.org \
--cc=linux-omap@vger.kernel.org \
--cc=marek.vasut@gmail.com \
--cc=miquel.raynal@bootlin.com \
--cc=richard@nod.at \
--cc=tony@atomide.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).