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.
next prev 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
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