Olimex Support Forum

OLinuXino Android / Linux boards and System On Modules => iMX233 => Topic started by: Fadil Berisha on November 07, 2012, 06:03:18 am

Title: Kernel 3.x - testing i2c support
Post by: Fadil Berisha on November 07, 2012, 06:03:18 am
i2c driver for imx23 is included in kernel 3.x. To add i2c support on olinuxino needed to patch kernel source with patch available here:
https://www.dropbox.com/s/v9z0q9mkmoa5vsm/0001-MXS-imx23-olinuxino-Add-i2c-support.patch (https://www.dropbox.com/s/v9z0q9mkmoa5vsm/0001-MXS-imx23-olinuxino-Add-i2c-support.patch)

Following code define i2c support on olinuxino:

         i2c0: i2c@80058000 {
            pinctrl-names = "default";
            pinctrl-0 = <&i2c1_pins_a>;
            status = "okay";
         };

Example-1: MOD-IO2 board
MOD-IO2 has i2c interface to connect external  RELAYs and GPIOs to any boards with UEXT connector.
Test is done with kernel 3.7.0-rc3-next-20121102-dirty and utility i2c-tool available from Olimex web site.
To activate both relays, run command:

./i2c-tool -w 0 0x48 4 0x02 0xA0 0x40 0x03

here is response:

SLAVE ADDRESS: 0x48
NUMBER OF BYTES TO WRITE: 4
MEMORY ALLOCATED AT ADDRESS: 0x743008
/dev/i2c-0 OPENDED!
WRITE:SUCCESS

to deactivate relays, run:

./i2c-tool -w 0 0x48 4 0x02 0xA0 0x40 0x00

response:

SLAVE ADDRESS: 0x48
NUMBER OF BYTES TO WRITE: 4
MEMORY ALLOCATED AT ADDRESS: 0x1DAC008
/dev/i2c-0 OPENDED!
WRITE:SUCCESS

Following photo shown olinuxino-mini MOD-IO2 with activated relays: 
(http://farm9.staticflickr.com/8347/8162855153_850f9a276e.jpg)

If device attached on i2c UEXT connector need linux driver, previous code need to adapted by end user.

Example-2: EEPROM atmel,24c128

         i2c0: i2c@80058000 {
            pinctrl-names = "default";
            pinctrl-0 = <&i2c1_pins_a>;
            status = "okay";
            
            eeprom: eeprom@51 {
               compatible = "atmel,24c128";
               reg = <0x51>;
               pagesize = <32>;
            };
         };


Acknowledgements

Fabio Estevam, Freescale; Providing assistance and guidance in development of i2c patch
Tsvetan Usunov, Olimex:  Providing hardware for testing of i2c interface

Fadil Berisha
Title: Re: Kernel 3.x - testing i2c support
Post by: olimex on November 07, 2012, 01:11:24 pm
Amazing! Big THANKS for your efforts, if you need any other hardware you need to test/play with just let me know ;)

So now we have in 3.x: SPI, I2C, UART, USB, SD-card, GPIOs and only LRADC, Audio and Video left unimplemented from all features iMX233 have?
Title: Re: Kernel 3.x - testing i2c support
Post by: Fabio Estevam on November 08, 2012, 06:05:36 pm
LRADC is already supported in 3.7-rc4.

Regards,

Fabio Estevam
Title: Re: Kernel 3.x - testing i2c support
Post by: robwoj on November 14, 2012, 11:24:52 am
Hi,

When applied to linux-3.7-rc5 /dev/i2c-0 appeared. I have some questions now.

Quote from: Fadil Berisha on November 07, 2012, 06:03:18 am

If device attached on i2c UEXT connector need linux driver, previous code need to adapted by end user.

Example-2: EEPROM atmel,24c128

         i2c0: i2c@80058000 {
            pinctrl-names = "default";
            pinctrl-0 = <&i2c1_pins_a>;
            status = "okay";
            
            eeprom: eeprom@51 {
               compatible = "atmel,24c128";
               reg = <0x51>;
               pagesize = <32>;
            };
         };



Is changing imx23.dtsi and/or imx23-olinuxino.dts file necssary whenever I change connected devices, or only when such device need to load external module?
Let's say that I have PCF8574 device and I want to use Write/read operations only (eg. using olimex' i2c-tool or my own dedicated program). Must I change device tree files?

What is needed to get i2cdetect working? For now it says 'Error: Can't use SMBus Quick Write command on this bus'.

Thank you in advance, Robert
Title: Re: Kernel 3.x - testing i2c support
Post by: Fadil Berisha on November 14, 2012, 04:56:50 pm
Quote from: robwoj on November 14, 2012, 11:24:52 am

Is changing imx23.dtsi and/or imx23-olinuxino.dts file necssary whenever I change connected devices,


1. If device does not require driver - no need to change files,
2. If device need driver - need to change only imx23-olinuxino.dts file:

         i2c0: i2c@80058000 {
            pinctrl-names = "default";
            pinctrl-0 = <&i2c1_pins_a>;
            status = "okay";
            /* Add node for slave device here, e.g. PCF8574 */
         };

Compile new DT file and append DT file on kernel. For procedure see https://github.com/koliqi/imx23-olinuxino

Fadil Berisha


Title: Re: Kernel 3.x - testing i2c support
Post by: Niii on January 04, 2013, 11:25:08 pm
Hi,

I've some issues with i2c-tools.
Tested with linux-next git (3.8.0-rc1) and your modifications.

Now when I scan the i2c bus I've no longer error message about SMBUS.
But, after scanning address 0x30, I've got some errors about PIO reg.

Fadil, have you try scanning with i2c-tools ?
Maybe is DMA who are not ready ? (http://lxr.free-electrons.com/source/drivers/i2c/busses/i2c-mxs.c#L217)


[79108.240000] i2c i2c-0: master_xfer[0] W, addr=0x25, len=0
[79108.250000] mxs-i2c 80058000.i2c: addr: 0x0025, len: 0, flags: 0x0, stop: 1
[79108.250000] i2c i2c-0: ioctl, cmd=0x703, arg=0x26
[79108.250000] i2c i2c-0: ioctl, cmd=0x720, arg=0xbeb57c8c
[79108.250000] i2c i2c-0: master_xfer[0] W, addr=0x26, len=0
[79108.260000] mxs-i2c 80058000.i2c: addr: 0x0026, len: 0, flags: 0x0, stop: 1
[79108.260000] i2c i2c-0: ioctl, cmd=0x703, arg=0x27
[79108.260000] i2c i2c-0: ioctl, cmd=0x720, arg=0xbeb57c8c
[79108.260000] i2c i2c-0: master_xfer[0] W, addr=0x27, len=0
[79108.270000] mxs-i2c 80058000.i2c: addr: 0x0027, len: 0, flags: 0x0, stop: 1
[79108.270000] i2c i2c-0: ioctl, cmd=0x703, arg=0x28
[79108.270000] i2c i2c-0: ioctl, cmd=0x720, arg=0xbeb57c8c
[79108.270000] i2c i2c-0: master_xfer[0] W, addr=0x28, len=0
[79108.280000] mxs-i2c 80058000.i2c: addr: 0x0028, len: 0, flags: 0x0, stop: 1
[79108.280000] i2c i2c-0: ioctl, cmd=0x703, arg=0x29
[79108.280000] i2c i2c-0: ioctl, cmd=0x720, arg=0xbeb57c8c
[79108.280000] i2c i2c-0: master_xfer[0] W, addr=0x29, len=0
[79108.290000] mxs-i2c 80058000.i2c: addr: 0x0029, len: 0, flags: 0x0, stop: 1
[79108.290000] i2c i2c-0: ioctl, cmd=0x703, arg=0x2a
[79108.290000] i2c i2c-0: ioctl, cmd=0x720, arg=0xbeb57c8c
[79108.290000] i2c i2c-0: master_xfer[0] W, addr=0x2a, len=0
[79108.300000] mxs-i2c 80058000.i2c: addr: 0x002a, len: 0, flags: 0x0, stop: 1
[79108.300000] i2c i2c-0: ioctl, cmd=0x703, arg=0x2b
[79108.300000] i2c i2c-0: ioctl, cmd=0x720, arg=0xbeb57c8c
[79108.300000] i2c i2c-0: master_xfer[0] W, addr=0x2b, len=0
[79108.310000] mxs-i2c 80058000.i2c: addr: 0x002b, len: 0, flags: 0x0, stop: 1
[79108.310000] i2c i2c-0: ioctl, cmd=0x703, arg=0x2c
[79108.310000] i2c i2c-0: ioctl, cmd=0x720, arg=0xbeb57c8c
[79108.310000] i2c i2c-0: master_xfer[0] W, addr=0x2c, len=0
[79108.320000] mxs-i2c 80058000.i2c: addr: 0x002c, len: 0, flags: 0x0, stop: 1
[79108.320000] i2c i2c-0: ioctl, cmd=0x703, arg=0x2d
[79108.320000] i2c i2c-0: ioctl, cmd=0x720, arg=0xbeb57c8c
[79108.320000] i2c i2c-0: master_xfer[0] W, addr=0x2d, len=0
[79108.330000] mxs-i2c 80058000.i2c: addr: 0x002d, len: 0, flags: 0x0, stop: 1
[79108.330000] i2c i2c-0: ioctl, cmd=0x703, arg=0x2e
[79108.330000] i2c i2c-0: ioctl, cmd=0x720, arg=0xbeb57c8c
[79108.330000] i2c i2c-0: master_xfer[0] W, addr=0x2e, len=0
[79108.340000] mxs-i2c 80058000.i2c: addr: 0x002e, len: 0, flags: 0x0, stop: 1
[79108.340000] i2c i2c-0: ioctl, cmd=0x703, arg=0x2f
[79108.340000] i2c i2c-0: ioctl, cmd=0x720, arg=0xbeb57c8c
[79108.340000] i2c i2c-0: master_xfer[0] W, addr=0x2f, len=0
[79108.350000] mxs-i2c 80058000.i2c: addr: 0x002f, len: 0, flags: 0x0, stop: 1
[79108.360000] i2c i2c-0: ioctl, cmd=0x703, arg=0x30
[79108.360000] i2c i2c-0: ioctl, cmd=0x720, arg=0xbeb57c8c
[79108.360000] i2c i2c-0: master_xfer[0] R, addr=0x30, len=1
[79108.370000] mxs-i2c 80058000.i2c: addr: 0x0030, len: 1, flags: 0x1, stop: 1
[79108.380000] mxs-i2c 80058000.i2c: Failed to get PIO reg. write descriptor.
[79108.380000] i2c i2c-0: ioctl, cmd=0x703, arg=0x31
[79108.380000] i2c i2c-0: ioctl, cmd=0x720, arg=0xbeb57c8c
[79108.380000] i2c i2c-0: master_xfer[0] R, addr=0x31, len=1
[79108.390000] mxs-i2c 80058000.i2c: addr: 0x0031, len: 1, flags: 0x1, stop: 1
[79109.410000] mxs-i2c 80058000.i2c: Timeout!
[79109.410000] i2c i2c-0: ioctl, cmd=0x703, arg=0x32
[79109.410000] i2c i2c-0: ioctl, cmd=0x720, arg=0xbeb57c8c
[79109.410000] i2c i2c-0: master_xfer[0] R, addr=0x32, len=1
[79109.420000] mxs-i2c 80058000.i2c: addr: 0x0032, len: 1, flags: 0x1, stop: 1
[79109.430000] mxs-i2c 80058000.i2c: Failed to get PIO reg. write descriptor.
[79109.430000] i2c i2c-0: ioctl, cmd=0x703, arg=0x33
[79109.430000] i2c i2c-0: ioctl, cmd=0x720, arg=0xbeb57c8c
[79109.430000] i2c i2c-0: master_xfer[0] R, addr=0x33, len=1
[79109.440000] mxs-i2c 80058000.i2c: addr: 0x0033, len: 1, flags: 0x1, stop: 1
[79110.460000] mxs-i2c 80058000.i2c: Timeout!
Title: Re: Kernel 3.x - testing i2c support
Post by: Fadil Berisha on January 05, 2013, 12:28:38 am
Hi Niii
Test is done with kernel 3.7.0-rc3-next-20121102 and 3.7.1-stable using utility i2c-tool available from Olimex web site (found in software package of  MOD-IO2). i2c-tool working very well so I didn't had need to try another tool.

Fadil Berisha
Title: Re: Kernel 3.x - testing i2c support
Post by: Niii on January 05, 2013, 01:43:29 am
Fadil,

Have you a copy of your precompiled i2c-tool binary somewhere ?
I don't have windows OS with me at this time for compilation :/.

Thanks.
Title: Re: Kernel 3.x - testing i2c support
Post by: htarold on January 19, 2013, 12:03:52 pm
Hi all,

I'm having trouble also with i2c.  Specifically, a read or write results in either EINVAL with a kernel error "mxs-i2c 80058000.i2c: Failed to get PIO reg. write descriptor", or ETIMEDOUT, when using "i2c-tool -w ..." or "i2c-tool -r ...".

Output from strace:
...
open("/dev/i2c-0", O_RDWR)              = 3
write(1, "/dev/i2c-0 OPENDED!\n", 20/dev/i2c-0 OPENDED!
)   = 20
ioctl(3, 0x703, 0x18)                   = 0
write(3, " '", 2)                       = -1 ETIMEDOUT (Connection timed out)
...
Or:
...
open("/dev/i2c-0", O_RDWR)              = 3
write(1, "/dev/i2c-0 OPENDED!\n", 20/dev/i2c-0 OPENDED!
)   = 20
ioctl(3, 0x703, 0x18)                   = 0
write(3, " '", 2)                       = -1 EINVAL (Invalid argument)
...

I know the device (LSM303 compass/accel) works, it has been tested with other hardware.

There appears no signal on the SCL pin when I attach a scope.

I have tried the stock kernel that comes with the Arch linux image (http://archlinuxarm.org/platforms/armv5/olinuxino) which is 3.7.2, and also 3.7.1 patched and compiled per instructions in https://github.com/koliqi/imx23-olinuxino.

I would appreciate any help or pointers anyone has.

Thanks,
-harold
Title: Re: Kernel 3.x - testing i2c support
Post by: Niii on January 19, 2013, 12:53:27 pm
Hi,

Can you try this patch (tested on 3.8.0-rc3) :
https://www.dropbox.com/s/3jl58z6av6yfzwl/i2c_dma_reg-imx233_fix.patch
Source : http://permalink.gmane.org/gmane.linux.drivers.i2c/13798

It fix error on PIO and imx233 registers.
But your i2c hw bus will works only with "Read byte" commands(i2cdetect -r).

I've got nothing too with quick probe on my scope, it seems to be not supported (no reference in imx233 datasheet)

Nicolas
Title: Re: Kernel 3.x - testing i2c support
Post by: Fadil Berisha on January 20, 2013, 03:25:34 am
Quote from: Niii on January 19, 2013, 12:53:27 pm
Hi,

Can you try this patch (tested on 3.8.0-rc3) :



Excellent work. No more  "Failed to get PIO reg. write descriptor" error when tested with i2cdetect. My applaud and Karma +1


Fadil Berisha
Title: Re: Kernel 3.x - testing i2c support
Post by: htarold on January 20, 2013, 11:22:56 am
Hi Niii,

Thanks I will try this with 3.8.  Did you apply the new patch over the old ones or just this patch alone?

Are you saying i2c now actually works, albeit only in "read byte" mode?

Thanks,
-harold
Title: Re: Kernel 3.x - testing i2c support
Post by: Niii on January 20, 2013, 01:31:35 pm
Hi Harold,

Try this :
Just before compile your kernel, apply these three patchs :
1) Same as Fadil patch, but set compatibily for i2c0 to imx23 instead imx28.
https://www.dropbox.com/s/r6quykxgozuwiak/i2c_mxs-dts.patch

2) Patch from Marex with a minor fix (now INIT_COMPLETION is lowercase in driver, so hunk 4 fail with original patch).
https://www.dropbox.com/s/v07eehulrc4dv18/i2c_mxs-dma.patch

3) Patch for set correctly registers for imx23.
https://www.dropbox.com/s/pvbt9d883de0m6v/i2c_mxs-reg.patch

With Fadil, all mode works on 3.8.0-rc3.
For me, scan only works with -r option, and 50% scan bus fail at error -110.

I need to take a look at that.

Nicolas

Ps : For information i2c bus is on pins 23/24 CON1, and you need to solder jumpers for HW i2c (Micro manual section 6.11.1)

Title: Re: Kernel 3.x - testing i2c support
Post by: Niii on January 20, 2013, 07:21:35 pm
Hi,

I just made a patch to test debugfs, if someone wanna try :
https://www.dropbox.com/s/tdzhzmokpdqzkuw/i2c_mxs-debugfs.patch

Before a scan :

root@micro:~# cat /sys/kernel/debug/mxs-i2c/regs
MXS_I2C_DATA: 0x00000000
MXS_I2C_DEBUG0: 0x00100000
MXS_I2C_DEBUG0_CLR: 0x00100000


After a scan :

root@micro:~# cat /sys/kernel/debug/mxs-i2c/regs
MXS_I2C_DATA: 0x00000015
MXS_I2C_DEBUG0: 0x0010d000
MXS_I2C_DEBUG0_CLR: 0x0010d000



Nicolas
Title: Re: Kernel 3.x - testing i2c support
Post by: htarold on January 21, 2013, 12:02:13 pm
Hi Nicholas,

I have tried your suggested patches on 3.8-rc3, and I can get a response sometimes.  Alternate times it times out (errno = ETIMEDOUT = 110) as you observed.

Also if I read a larger buffer, I get:
[  363.140000] INFO: trying to register non-static key.
[  363.140000] the code is fine but needs lockdep annotation.
[  363.140000] turning off the locking correctness validator.
followed by an oops.

Is there any way to avoid the ETIMEOUT?

Thanks,
-harold
Title: Re: Kernel 3.x - testing i2c support
Post by: Niii on January 21, 2013, 12:10:43 pm
>Is there any way to avoid the ETIMEOUT?
For moment I don't know how.
I'm trying to found if there a relation about this and status registers.

But I don't understand why you and me have -110 error, and nothing for Fadil .
Update : Fadil has error -110 too.
Title: Re: Kernel 3.x - testing i2c support
Post by: Niii on January 22, 2013, 11:04:29 pm
There is a timeout error because of function mxs_i2c_pio_wait_dmareq() from i2c-mxs.c.
Sometimes bit 31(DMAREQ) in HW_I2C_DEBUG0 register (25.4.8 p1140) is set to 0, but for no error it should be 1.

I don't know why at this time ...
Title: Re: Kernel 3.x - testing i2c support
Post by: Niii on January 24, 2013, 02:14:04 am
Well, with a bus reset after a success command I've no timeout error.
Error is after select command in function mxs_i2c_pio_setup_xfer() :

   writel(MXS_I2C_CTRL0_RUN | MXS_CMD_I2C_SELECT, i2c->regs + MXS_I2C_CTRL0);


After this command the bit 31(DMAREQ) in HW_I2C_DEBUG0 should be 1, but sometimes it's 0, I don't know why ...
Maybe it's a ugly fix, but I reach my limit into debugging :)

Timeout patch :
https://www.dropbox.com/s/r4kling4kf8dtzq/i2c_mxs-timeout.patch
Full patch :
https://www.dropbox.com/s/0m9c6grkr4dp4j0/i2c_mxs-FULL.patch

Nicolas
Title: Re: Kernel 3.x - testing i2c support
Post by: htarold on January 24, 2013, 03:04:02 am
Hi Nicholas,

I've gone to the stock Arch image, which performs i2c well enough that I can now spend my time on other things.  Thanks for all your help.
-harold
Title: Re: Kernel 3.x - testing i2c support
Post by: lucio on January 28, 2013, 05:41:29 pm
Quote from: htarold on January 24, 2013, 03:04:02 am
Hi Nicholas,

I've gone to the stock Arch image, which performs i2c well enough that I can now spend my time on other things.  Thanks for all your help.
-harold


Specifically, which image is this?

I have been messing around with a bunch of options, ending with Linux 3.7.4, but the timeout problem persists.  I'd like to compare a known, working kernel with the sources I'm using, see what's missing.

Also, as a general question, I'm finding that earlier versions of the kernel allow a Go executable to run, a newer version reports an illegal instruction (details unknown, the reported "core" file does not materialise).  I presume I've left out some configuration detail, but there are so many, it would be hard for me to find the missing one. I have a feeling floating point stuff is missing, but I'm a bit of a newbie about all this.

Lucio.
Title: Re: Kernel 3.x - testing i2c support
Post by: Dataedge on January 29, 2013, 08:11:30 pm
Hi Lucio,

I'm currently using the ArchLinux image from :
http://archlinuxarm.org/platforms/armv5/olinuxino (http://archlinuxarm.org/platforms/armv5/olinuxino)

olinuxino kernel: [    0.000000] Linux version 3.7.2-2-ARCH (nobody@panda2) (gcc version 4.7.2 (GCC) ) #1 PREEMPT Thu Jan 17 07:51:19 UTC 2013
olinuxino kernel: [    0.000000] CPU: ARM926EJ-S [41069265] revision 5 (ARMv5TEJ), cr=00053177
olinuxino kernel: [    0.000000] CPU: VIVT data cache, VIVT instruction cache
olinuxino kernel: [    0.000000] Machine: Freescale i.MX23 (Device Tree), model: i.MX23 Olinuxino Low Cost Board


Installed GCC+make then compiled "i2c-tool" , tested with a LM75 device (i2c address: 0x48):

[root@olinuxino i2c-tool]# ./i2c-tool -rw 0 0x48 2 1 0x00
Number of parameters: 7
SLAVE ADDRESS: 0x48
NUMBER OF BYTES TO READ: 2
NUMBER OF BYTES TO WRITE: 1
/dev/i2c-0 OPENDED!
MEMORY ALLOCATED AT ADDRESS: 0xA04008
MEMORY ALLOCATED AT ADDRESS: 0xA04018

PACKET DATA:
--------------------
ADDRESS: 0x48
FLAG: 0x00
LENGHT: 0x04

ADDRESS: 0x48
FLAG: 0x01
LENGHT: 0x04
MESSAGES: 2
SENDING:DONE
BYTE[0]: 0x12
BYTE[1]: 0x60
Title: Re: Kernel 3.x - testing i2c support
Post by: tcmichals on January 29, 2013, 08:28:26 pm
I've also been looking at this for awhile, 3 months now, if accessing a i2c address that is not mapped by a device on the bus, DMA does not terminate properly.  In the 3.7, I just added a dmaengine_terminate_all(i2c->dmach); each time a i2c access is called.  Thus clearing any DMA issues.
Title: Re: Kernel 3.x - testing i2c support
Post by: Fadil Berisha on January 29, 2013, 09:27:45 pm
Quote from: tcmichals on January 29, 2013, 08:28:26 pm
I've also been looking at this for awhile, 3 months now, if accessing a i2c address that is not mapped by a device on the bus, DMA does not terminate properly.  In the 3.7, I just added a dmaengine_terminate_all(i2c->dmach); each time a i2c access is called.  Thus clearing any DMA issues.

Is that included in your old patch?
Title: Re: Kernel 3.x - testing i2c support
Post by: tcmichals on January 29, 2013, 09:38:13 pm
Yes, it is in one of my old patches. It was not accepted into the kernel.

Here is the modification to the code:
static int mxs_i2c_dma_setup_xfer(struct i2c_adapter *adap,
struct i2c_msg *msg, uint32_t flags)
{
struct dma_async_tx_descriptor *desc;
struct mxs_i2c_dev *i2c = i2c_get_adapdata(adap);

if (msg->flags & I2C_M_RD) {
i2c->dma_read = 1;
i2c->addr_data = (msg->addr << 1) | I2C_SMBUS_READ;

/*
* SELECT command.
*/

/* Queue the PIO register write transfer. */
i2c->pio_data[0] = MXS_CMD_I2C_SELECT;
desc = dmaengine_prep_slave_sg(i2c->dmach,
(struct scatterlist *)&i2c->pio_data[0],
1, DMA_TRANS_NONE, 0);
if (!desc) {
dev_err(i2c->dev,
"Failed to get PIO reg. write descriptor.\n");
goto select_init_pio_fail;
}
dmaengine_terminate_all(i2c->dmach); // <--- Add this to clear any old pending DMA..

/* Queue the DMA data transfer. */
sg_init_one(&i2c->sg_io[0], &i2c->addr_data, 1);
dma_map_sg(i2c->dev, &i2c->sg_io[0], 1, DMA_TO_DEVICE);
desc = dmaengine_prep_slave_sg(i2c->dmach, &i2c->sg_io[0], 1,
DMA_MEM_TO_DEV,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc) {
dev_err(i2c->dev,
"Failed to get DMA data write descriptor.\n");
goto select_init_dma_fail;
}
Title: Re: Kernel 3.x - testing i2c support
Post by: lucio on February 01, 2013, 11:17:41 am
Quote from: Dataedge on January 29, 2013, 08:11:30 pm
Hi Lucio,

I'm currently using the ArchLinux image from :
http://archlinuxarm.org/platforms/armv5/olinuxino (http://archlinuxarm.org/platforms/armv5/olinuxino)

olinuxino kernel: [    0.000000] Linux version 3.7.2-2-ARCH (nobody@panda2) (gcc version 4.7.2 (GCC) ) #1 PREEMPT Thu Jan 17 07:51:19 UTC 2013
olinuxino kernel: [    0.000000] CPU: ARM926EJ-S [41069265] revision 5 (ARMv5TEJ), cr=00053177
olinuxino kernel: [    0.000000] CPU: VIVT data cache, VIVT instruction cache
olinuxino kernel: [    0.000000] Machine: Freescale i.MX23 (Device Tree), model: i.MX23 Olinuxino Low Cost Board



I have the same kernel version (3.7.2-2-ARCH) running right now, but the output from running the recommended:

./i2c-tool -w 0 0x48 4 0x02 0xa0 0x40 0x03

still comes back with a time out error.  I can't believe that the user level application can be responsible, so I'm beginning to suspect the MOD-IO2 device from Olimex.

In case somebody here wants to comment, the MOD-IO2 is pristine as received from Olimex, is powered with the specified 12V DC and connected with a short ribbon cable (15 cm, I believe - female plugs at each end).   Nothing else is connected to it.

I will continue to experiment, there is much I need to learn about, but getting the MOD-IO2 to work as specified would be my first objective.

Thanks to all that have helped so far.

Lucio.

PS: I just have to fix the spelling errors in i2c-tool.c, they drive me insane, who do I submit the fixes to?
Title: Re: Kernel 3.x - testing i2c support
Post by: Niii on February 24, 2013, 12:24:06 pm
Patch tested on linux-next20130218.
https://www.dropbox.com/s/5t5ewcvtsuh4oba/next20130218_i2c-mxs.c.patch

On this next, I've an error when I read data with i2get. It always return i2c device address from MXS_I2C_DATA.
It seems the loop read too fast data after writing "read command" into MXS_I2C_CTRL0.
With a delay of 200us before read MXS_I2C_DATA, it works for me.

If anyone want try.
Title: Re: Kernel 3.x - testing i2c support
Post by: Dataedge on February 24, 2013, 07:50:50 pm
Hey Nicolas,

confirmed, your patch works in my system too! You can safely apply this from 3.8 next20130218 kernel onwards. Checked with my device tree files :

imx23.dtsi chunk:

...
i2c0: i2c@80058000 {
#address-cells = <1>;
#size-cells = <0>;
compatible = "fsl,imx23-i2c";
reg = <0x80058000 0x2000>;
interrupts = <27 26>;
clock-frequency = <100000>;
fsl,i2c-dma-channel = <3>;
status = "disabled";
};
...


imx23-olinuxino.dts chunk

...
i2c0: i2c@80058000 {
pinctrl-names = "default";
pinctrl-0 = <&i2c1_pins_a>;
status = "okay";

tsl2561: tsl2561@29 {
compatible = "taos,tsl2561";
reg = <0x29>;
};

lm75: lm75@48 {
compatible = "national,lm75";
reg = <0x48>;
};
};

...


The above because I've a LM75 temperature sensor (I2C addr.0x48) and a TSL2561 light sensor (I2C addr.0x29).
Enabled in kernel menuconfig under Device Drivers:
industrial I/O subsystem ->  Light sensors -> TAOS TSL2560, TSL2561, TSL2562 and TSL2563 ambient light sensors
Hardware Monitoring support -> National Semiconductor LM75 and compatibles

Title: lradc
Post by: lambda on June 15, 2013, 05:32:26 am
Quote from: Fabio Estevam on November 08, 2012, 06:05:36 pm
LRADC is already supported in 3.7-rc4.


Actually, not. The driver is there but the devicetree setup is still
lacking in recent kernels.

The quick hack: just setting status from "disabled" to "okay" gives me
something. (Not yet tested with some real HW.)

A proper fix likely will need some pinctrl setup, but I don't understand
that well enough to do it myself.

Harald