All of lore.kernel.org
 help / color / mirror / Atom feed
From: Peter Korsgaard <jacmet@sunsite.dk>
To: Andreas Larsson <andreas@gaisler.com>
Cc: linux-i2c@vger.kernel.org, Jean Delvare <khali@linux-fr.org>,
	Ben Dooks <ben-linux@fluff.org>,
	Wolfram Sang <w.sang@pengutronix.de>,
	Grant Likely <grant.likely@secretlab.ca>,
	Rob Herring <rob.herring@calxeda.com>,
	linux-kernel@vger.kernel.org,
	devicetree-discuss@lists.ozlabs.org, software@gaisler.com
Subject: Re: [PATCH 2/2] i2c: i2c-ocores: Add support for the GRLIB port of the controller and custom getreg and setreg functions
Date: Tue, 23 Oct 2012 22:24:33 +0200	[thread overview]
Message-ID: <87sj95lywu.fsf@macbook.be.48ers.dk> (raw)
In-Reply-To: <1351004637-11049-3-git-send-email-andreas@gaisler.com> (Andreas Larsson's message of "Tue, 23 Oct 2012 17:03:57 +0200")

>>>>> "Andreas" == Andreas Larsson <andreas@gaisler.com> writes:

 Andreas> The registers in the GRLIB port of the controller are 32-bit
 Andreas> and in big endian byte order. The PRELOW and PREHIGH registers
 Andreas> are merged into one register. The subsequent registers have
 Andreas> their offset decreased accordingly. Hence the register access
 Andreas> needs to be handled in a non-standard manner using custom
 Andreas> getreg and
 Andreas> setreg functions.

 Andreas> Signed-off-by: Andreas Larsson <andreas@gaisler.com>
 Andreas> ---
 Andreas>  drivers/i2c/busses/i2c-ocores.c |   57 +++++++++++++++++++++++++++++++++++++-
 Andreas>  1 files changed, 55 insertions(+), 2 deletions(-)

 Andreas> diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c
 Andreas> index 1eb8a65..e3df62f 100644
 Andreas> --- a/drivers/i2c/busses/i2c-ocores.c
 Andreas> +++ b/drivers/i2c/busses/i2c-ocores.c
 Andreas> @@ -4,6 +4,9 @@
 Andreas>   *
 Andreas>   * Peter Korsgaard <jacmet@sunsite.dk>
 Andreas>   *
 Andreas> + * Support for the GRLIB port of the controller by
 Andreas> + * Andreas Larsson <andreas@gaisler.com>
 Andreas> + *
 Andreas>   * This file is licensed under the terms of the GNU General Public License
 Andreas>   * version 2.  This program is licensed "as is" without any warranty of any
 Andreas>   * kind, whether express or implied.
 Andreas> @@ -38,6 +41,8 @@ struct ocores_i2c {
 Andreas>  	int nmsgs;
 Andreas>  	int state; /* see STATE_ */
 Andreas>  	int clock_khz;
 Andreas> +	void (*setreg)(struct ocores_i2c *i2c, int reg, u8 value);
 Andreas> +	u8 (*getreg)(struct ocores_i2c *i2c, int reg);
 Andreas>  };
 
 Andreas>  /* registers */
 Andreas> @@ -73,7 +78,9 @@ struct ocores_i2c {
 
 Andreas>  static inline void oc_setreg(struct ocores_i2c *i2c, int reg, u8 value)
 Andreas>  {
 Andreas> -	if (i2c->reg_io_width == 4)
 Andreas> +	if (i2c->setreg)
 Andreas> +		i2c->setreg(i2c, reg, value);
 Andreas> +	else if (i2c->reg_io_width == 4)
 Andreas>  		iowrite32(value, i2c->base + (reg << i2c->reg_shift));
 Andreas>  	else if (i2c->reg_io_width == 2)
 Andreas>  		iowrite16(value, i2c->base + (reg << i2c->reg_shift));
 Andreas> @@ -83,7 +90,9 @@ static inline void oc_setreg(struct ocores_i2c *i2c, int reg, u8 value)
 
 Andreas>  static inline u8 oc_getreg(struct ocores_i2c *i2c, int reg)
 Andreas>  {
 Andreas> -	if (i2c->reg_io_width == 4)
 Andreas> +	if (i2c->getreg)
 Andreas> +		return i2c->getreg(i2c, reg);
 Andreas> +	else if (i2c->reg_io_width == 4)
 Andreas>  		return ioread32(i2c->base + (reg << i2c->reg_shift));
 Andreas>  	else if (i2c->reg_io_width == 2)
 Andreas>  		return ioread16(i2c->base + (reg << i2c->reg_shift));
 Andreas> @@ -91,6 +100,40 @@ static inline u8 oc_getreg(struct ocores_i2c *i2c, int reg)
 Andreas>  		return ioread8(i2c->base + (reg << i2c->reg_shift));
 Andreas>  }
 
 Andreas> +/* Read and write functions for the GRLIB port of the controller. Registers are
 Andreas> + * 32-bit big endian and the PRELOW and PREHIGH registers are merged into one
 Andreas> + * register. The subsequent registers has their offset decreased accordingly. */
 Andreas> +static u8 oc_getreg_grlib(struct ocores_i2c *i2c, int reg)
 Andreas> +{
 Andreas> +	u32 rd;
 Andreas> +	int rreg = reg;
 Andreas> +	if (reg != OCI2C_PRELOW)
 Andreas> +		rreg--;
 Andreas> +	rd = ioread32be(i2c->base + (rreg << i2c->reg_shift));
 Andreas> +	if (reg == OCI2C_PREHIGH)
 Andreas> +		return (u8)rd >> 8;
 Andreas> +	else
 Andreas> +		return (u8)rd;
 Andreas> +}
 Andreas> +
 Andreas> +static void oc_setreg_grlib(struct ocores_i2c *i2c, int reg, u8 value)
 Andreas> +{
 Andreas> +	u32 curr, wr;
 Andreas> +	int rreg = reg;
 Andreas> +	if (reg != OCI2C_PRELOW)
 Andreas> +		rreg--;
 Andreas> +	if (reg == OCI2C_PRELOW || reg == OCI2C_PREHIGH) {
 Andreas> +		curr = ioread32be(i2c->base + (rreg << i2c->reg_shift));
 Andreas> +		if (reg == OCI2C_PRELOW)
 Andreas> +			wr = (curr & 0xff00) | value;
 Andreas> +		else
 Andreas> +			wr = (((u32)value) << 8) | (curr & 0xff);
 Andreas> +	} else {
 Andreas> +		wr = value;
 Andreas> +	}
 Andreas> +	iowrite32be(wr, i2c->base + (rreg << i2c->reg_shift));

Are all platforms using i2c-ocores guaranteed to provide ioread32be /
iowrite32be or should we stick an #ifdef CONFIG_SPARC around it?



-- 
Bye, Peter Korsgaard

  reply	other threads:[~2012-10-23 20:24 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-23 15:03 [PATCH 0/2] i2c: i2c-ocores: Add support for sparc, custom set and get functions, and the GRLIB port of the controller Andreas Larsson
2012-10-23 15:03 ` Andreas Larsson
2012-10-23 15:03 ` [PATCH 1/2] i2c: i2c-ocores: Add irq support for sparc Andreas Larsson
2012-10-23 15:03   ` Andreas Larsson
2012-10-23 20:13   ` Peter Korsgaard
2012-10-23 20:13     ` Peter Korsgaard
2012-10-24  9:05     ` Andreas Larsson
2012-10-24  9:05       ` Andreas Larsson
2012-10-23 15:03 ` [PATCH 2/2] i2c: i2c-ocores: Add support for the GRLIB port of the controller and custom getreg and setreg functions Andreas Larsson
2012-10-23 15:03   ` Andreas Larsson
2012-10-23 20:24   ` Peter Korsgaard [this message]
2012-10-24  9:05     ` Andreas Larsson
2012-10-24 11:48       ` Peter Korsgaard
2012-10-24 11:48         ` Peter Korsgaard

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=87sj95lywu.fsf@macbook.be.48ers.dk \
    --to=jacmet@sunsite.dk \
    --cc=andreas@gaisler.com \
    --cc=ben-linux@fluff.org \
    --cc=devicetree-discuss@lists.ozlabs.org \
    --cc=grant.likely@secretlab.ca \
    --cc=khali@linux-fr.org \
    --cc=linux-i2c@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=rob.herring@calxeda.com \
    --cc=software@gaisler.com \
    --cc=w.sang@pengutronix.de \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.