public inbox for u-boot@lists.denx.de
 help / color / mirror / Atom feed
From: txcotrader <txcotrader@gmail.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] PPC4XX Custom Board - Failing to read I2C
Date: Thu, 4 Apr 2013 17:04:59 -0700 (PDT)	[thread overview]
Message-ID: <1365120299377-151609.post@n7.nabble.com> (raw)
In-Reply-To: <1364939304023-151298.post@n7.nabble.com>

After looking deeper I've found a difference in register values when
performing drivers/i2c/ppc4xx_i2c.c->i2c_transfer function.

v1.7.02 code yields:

/* Transfer is in progress
         * we have to wait for upto 5 bytes of data
         * 1 byte chip address+r/w bit then bc bytes
         * of data.
         * udelay(10) is 1 bit time at 100khz
         * Doubled for slop. 20 is too small.
         */
        i = 2*5*8;
        do {
            /* Get status */
            status = in_8((u8 *)IIC_STS);
            printf("gd_ do status->i = %d, status = %d\n", i, status);
            udelay(20);
            i--;
        } while ((status & IIC_STS_PT) && !(status & IIC_STS_ERR) && (i >
0));

gd_ do status->i = 80, status = 40


v2013.01.01 Yields:
        i = 2 * 5 * 8;
        do {
            /* Get status */
            status = in_8(&i2c->sts);
            printf("gd_ do status->i = %d, status = %d\n", i, status);
            udelay(10);
            i--;
        } while ((status & IIC_STS_PT) && !(status & IIC_STS_ERR) &&
             (i > 0));

gd_ do status->i = 80, status = 40

v1.7.02 - include/4xx_i2c.h:#define IIC_STS	
(I2C_REGISTERS_BASE_ADDRESS+IICSTS)
v2013.01.01 - struct ppc4xx_i2c *i2c = (struct ppc4xx_i2c *)I2C_BASE_ADDR;

Newb question, but I should be able to add an offset to correct this issue
right?

Thanks






--
View this message in context: http://u-boot.10912.n7.nabble.com/PPC4XX-Custom-Board-Failing-to-read-I2C-tp151298p151609.html
Sent from the U-Boot mailing list archive at Nabble.com.

  parent reply	other threads:[~2013-04-05  0:04 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-04-02 21:48 [U-Boot] PPC4XX Custom Board - Failing to read I2C txcotrader
2013-04-03  0:51 ` Stefan Roese
2013-04-03 16:15   ` txcotrader
2013-04-03 17:08     ` Stefan Roese
2013-04-03 17:29       ` txcotrader
2013-04-03 17:54         ` Anatolij Gustschin
2013-04-03 19:09           ` txcotrader
2013-04-04 17:43             ` txcotrader
2013-04-04 22:18             ` Rommel Custodio
2013-04-04 22:26               ` txcotrader
2013-04-05  0:04 ` txcotrader [this message]
2013-04-05  6:04   ` Stefan Roese
2013-04-08 12:26     ` txcotrader
2013-04-08 13:33       ` Stefan Roese
2013-04-08 14:16     ` txcotrader
2013-04-08 14:34       ` Stefan Roese
2013-04-08 19:54         ` txcotrader
2013-04-09 15:49           ` Stefan Roese
2013-07-24 22:58             ` txcotrader
2013-07-25  4:33               ` Stefan Roese

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=1365120299377-151609.post@n7.nabble.com \
    --to=txcotrader@gmail.com \
    --cc=u-boot@lists.denx.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox