[dwi2c PATCH v1] dwi2c add offsets to reads

[Duffin, CooperX]

Hello Simon, 

I wasn’t using the test/dm/i2c I this was tested using hardware where I was using the dm_i2c_read() function. I just tried to use the test/dm/i2c where I am following the README but I keep getting  "sdl2-config: Command not found". I suspect it would also fail where it is trying to read but I will have to get test/dm/i2c working before I know for sure.

Essentially my test was  

int uboot_app (int argc, char * const argv[])
{
	uint8_t buf[10];
	uint8_t read_buf[5];
	uint8_t dev_addr;
	uint32_t bus_speed;
	//i2c_bus device pointer
	struct udevice *i2c_led;
	struct udevice *bus;
	app_startup(argv);
	/* Print the ABI version */
	printf ("Example expects ABI version %d\n", XF_VERSION);
	printf ("Actual U-Boot ABI version %d\n", (int)get_version());

	dev_addr = 0x60;
	bus_speed = 100000; //100KHz
	printf("starting test i2c\n");
	buf[0] = 'b';
	buf[1] = 'o';
	buf[2] = 'o';
	buf[3] = 't';
	//Get i2c chip, init the code
	printf("init starting\n");
	if(i2c_get_chip_for_busnum(0 , 0x60, 1, &i2c_led)!=0){
		printf("ERROR: no device found at %x \n",dev_addr);
		return (0);
	}
	uclass_get_device_by_seq(UCLASS_I2C, 0, &bus);
	printf("Setting bus speed to %d\n", bus_speed);
	if(dm_i2c_set_bus_speed(bus,bus_speed)!=0){
		printf("ERROR: Cannot set buspeed\n");
		return (0);
	}
	printf("i2c_led name is %s\n",i2c_led->name);
	if(i2c_led == NULL){
		printf("ERROR i2c_led 0 is null\n");
		return (0);	
	}
	printf("Writing\n");
	for(unsigned int a =0; a< 4; a++){
		if(dm_i2c_write(i2c_led,a,&buf[a],1)!=0){
			printf("ERROR writing\n");
			return (0);
		}
	}
	
	printf("Reading\n");
	for(unsigned int a =0; a< 4; a++){
		if(dm_i2c_read(i2c_led,a,&read_buf[a],1)!=0){
			printf("ERROR writing\n");
			return (0);
		}
	}
	printf("read buffer is %c, %c, %c, %c \n",read_buf[0],read_buf[1], read_buf[2],read_buf[3]);
	printf ("\n\n");
	return (0);
}

## Starting application at 0x0C100000 ...
Example expects ABI version 10
Actual U-Boot ABI version 10
starting test i2c
init starting
Setting bus speed to 100000
i2c_led name is generic_60
Writing
Reading
read buffer is o, o, o, o
 
with the fix I get:

## Starting application at 0x0C100000 ...
Example expects ABI version 10
Actual U-Boot ABI version 10
starting test i2c
init starting
Setting bus speed to 100000
i2c_led name is generic_60
Writing
Reading
read buffer is b, o, o, t

which is correct. Similarly if I stop auto boot I get a similar result:

Hit any key to stop autoboot:  0 
device # i2c 
i2c - I2C sub-system

Assuming I write "boot" to the device
device # i2c dev 0
Setting bus to 0
device # i2c md 0x60 0 4
0000: 6f 6f 6f 6f    oooo

With the fix/patch I get:
 
device# i2c md 0x60 0 4
0000: 62 6f 6f 74    boot

Which is correct. Also the reads were working in linux leading to my original suspicion that there might be something going on in the driver. Hopefully that answers your question let me know if you have anymore. 

Best regards,

-Cooper Duffin
-----Original Message-----
From: Simon Glass <sjg at chromium.org> 
Sent: Friday, November 6, 2020 10:51 AM
To: Duffin, CooperX <cooperx.duffin at intel.com>
Cc: U-Boot Mailing List <u-boot at lists.denx.de>; uboot-snps-arc at synopsys.com; Tom Rini <trini at konsulko.com>; Robert Beckett <bob.beckett at collabora.com>; Heiko Schocher <hs at denx.de>; Wolgang Denk <wd at denx.de>; Ian Ray <ian.ray at ge.com>
Subject: Re: [dwi2c PATCH v1] dwi2c add offsets to reads

Hi Cduffinx,

On Thu, 5 Nov 2020 at 14:26, cduffinx <cooperx.duffin at intel.com> wrote:
>
> modify the designware_i2c_xfer function to use 1 byte per address, it 
> was set to 0 before which makes it think its reading a register type. 
> Added offset of where it is supposed to read from. Before it was 
> always reading from offset 0 despite specifying the offset in the 
> higher level function.
>
> Signed-off-by: Cooper Duffin <cooperx.duffin at intel.com>
> Signed-off-by: cduffinx <cooperx.duffin at intel.com>
> ---
>
>  drivers/i2c/designware_i2c.c | 5 +++--
>  drivers/i2c/i2c-uclass.c     | 1 +
>  include/i2c.h                | 1 +
>  3 files changed, 5 insertions(+), 2 deletions(-)
>

Thanks for the patch!

Is there a test that was failing before (test/dm/i2c.c) or should we add a new one to catch this?

Regards,
Simon