>From the following error message, I2C controller can't receive ACK from
I2C client, so please make sure that the pins of I2C have been
initialized properly, or you can measure the tx signal and rx signal on
the right pins.
B.R,
Hongjun
________________________________
From: Uma Kanta Patro [mailto:upa...@implantaire.com]
Sent: Wednesday, September 09, 2009 9:13 PM
To: Chen Hongjun-R66092; linuxppc-dev@lists.ozlabs.org
Subject: RE: Queries regarding I2C and GPIO driver for Freescale
MPC5121e in Linux2.6.24 of BSP: MPC512xADS_20090603-ltib.iso
Hi Chen Hongjun-R66092,
Thanks for your response.
Actually for the GPIO driver I am having some success and it is
in progress.
But regarding the I2C chip(client) driver I am running witout
any progress.
Actually I followed the existing driver
$(LINUX)\drivers\rtc\rtc-m41t80.c (for the RTC M41T62 existing on the
ADS5121Rev4.1 board).
I made a legacy style driver with attach_adapter and
detach_client functions defined.
For testing purpose I geve the chip address as 0x68(address of
M41T62 existing on the board). But when I tried ot insert my driver I
get the error message as:
[r...@freescale chips]# insmod dis_fpc.ko
[ 177.808848] i2c 0-0068: uevent
[ 498.528032] In dis_fpc_init
[ 498.531851] i2c-core: driver [dis_fpc] registered
[ 498.532446] In dis_fpc_attach_adapter
[ 498.536827] i2c-adapter i2c-0: found normal entry for adapter
0, addr 0x55
[ 498.537730] i2c-adapter i2c-0: master_xfer[0] W, addr=0x55,
len=0
[ 498.538533] Doing write 0 bytes to 0x55 - 1 of 1 messages
[ 498.539770] I2C: No RXAK
[ 498.540970] In dis_fpc_attach_adapter
[ 498.554500] i2c-adapter i2c-1: found normal entry for adapter
1, addr 0x55
[ 498.555166] i2c-adapter i2c-1: master_xfer[0] W, addr=0x55,
len=0
[ 498.555872] Doing write 0 bytes to 0x55 - 1 of 1 messages
[ 498.556785] I2C: MAL
[ 498.557476] In dis_fpc_attach_adapter
[ 498.565733] i2c-adapter i2c-2: found normal entry for adapter
2, addr 0x55
[ 498.566377] i2c-adapter i2c-2: master_xfer[0] W, addr=0x55,
len=0
[ 498.567082] Doing write 0 bytes to 0x55 - 1 of 1 messages
[ 498.568240] I2C: No RXAK
So can you tell me what other places do I need to change the
configurations( like i2c_platform_data definition, linking the chip to
the specific I2C module(0/1/2) with the adapter, configuring the speed
of I2C communication etc).
I would like to get any suggestion on making the I2C chip driver
inpowerpc platform.
Thanks & Regards,
Uma
From: Chen Hongjun-R66092 [mailto:hong-jun.c...@freescale.com]
Sent: Wednesday, September 09, 2009 5:39 AM
To: Uma Kanta Patro; linuxppc-dev@lists.ozlabs.org
Subject: RE: Queries regarding I2C and GPIO driver for Freescale
MPC5121e in Linux2.6.24 of BSP: MPC512xADS_20090603-ltib.iso
One I2C driver has been included in 0603 bsp, you can refer to
it.
It has no specific driver for GPIO, but you can find some
initializing code for GPIO in arch/powerpc/platforms/512x/mpc5125_ads.c.
and mpc512x_pm_test.c.
________________________________
From:
linuxppc-dev-bounces+hong-jun.chen=freescale....@lists.ozlabs.org
[mailto:linuxppc-dev-bounces+hong-jun.chen=freescale....@lists.ozlabs.or
g] On Behalf Of Uma Kanta Patro
Sent: Tuesday, September 08, 2009 6:56 PM
To: linuxppc-dev@lists.ozlabs.org
Subject: Queries regarding I2C and GPIO driver for
Freescale MPC5121e in Linux2.6.24 of BSP: MPC512xADS_20090603-ltib.iso
Hi all,
I am a newbie to the powerpc linux
kernel, but I have worked on some drivers in arm architecture. I am
finding powerpc architecture to be fully different than that.
I am working on Freescale MPC5121e with the BSP
MPC512xADS_20090603-ltib.iso running in it on the ADS512101 Rev4.1
development kit.
Can anyone help me in finding some documentation for
understanding and working on the powerpc kernel. Any links to the
powerpc forums will also be appreciable.
-> Currently I am going to develop an I2C client driver
for one slave microcontroller of our project.
I have some knowledge in the I2C client driver
making(legacy style and new style).
I made a basic I2C client driver to probe for the chip
address and for testing I gave it the chip address 0x68(I2C chip address
of the M4T162 RTC, present on the board).
But while inserting my driver I am getting failure
message for the detection of my chip.
So I would like to know what other formalities am I
lagging in my I2C chip driver.
-> Also I am in a need for the GPIO driver for my
controller ot get interrupt on ht estate change. When I searched in the
kernel code I could not find any procedure to do that, also I could not
find out the procedure to access either any GPIO pin macros or any
register to remap with ioremap(). So please guide me in finding the
proper way to do the GPIO accessing and interrupt registration.
Will the ioremap() work on powerpc arch? If yes where
can I find the memory mapping(register definitions) to use for my GPIO
driver making.
Thanks for patience in reading my queries.
Any help is appreciable.
Thanks & Regards,
Uma
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