Re: [PATCH/RFC] [POWERPC] Add i2c pins to dts and board setup on 01-31-08
From: Jochen Friedrich <jochen@scram.de>
Date: 2008-02-14 11:40:08
Hi Nima,
I've got a couple of comments about the above patch - I'm not quite sure how to add my comments to the ozlab.org site.
simply replying to the original mail will add your comments.
1 -
-- a/arch/powerpc/boot/dts/mpc8272ads.dts
[snip]
+ i2c@11860 {
+ compatible = "fsl,mpc8248-i2c",
[NIMA] Are you sure it should be mpc8248, or do you want 8272. I know
they are essentially the same chip, but just to avoid confusion, it
maybe better as 8272.Good catch, thanks! As i don't have a CPM2 chip myself, i had a tester with a MPC8248. I just took his dts parts.
quoted hunk
2-+++ b/arch/powerpc/platforms/82xx/mpc8272_ads.c@@ -96,6 +96,11 @@ static struct cpm_pin mpc8272_ads_pins[] = { {1, 31, CPM_PIN_OUTPUT | CPM_PIN_PRIMARY}, {2, 16, CPM_PIN_INPUT | CPM_PIN_PRIMARY}, {2, 17, CPM_PIN_INPUT | CPM_PIN_PRIMARY}, + + /* I2C */ + {3, 26, CPM_PIN_INPUT | CPM_PIN_SECONDARY | CPM_PIN_OPENDRAIN}, + {3, 27, CPM_PIN_INPUT | CPM_PIN_SECONDARY | CPM_PIN_OPENDRAIN},[NIMA] The MPC8272 manual states that it should be pins 14/15 and not 26/27.
Ah thanks.
However, in all my accesses, - 1st write is successful - 1st read fails (times out) - 2nd read succeeds Here is the debug log: i2c-adapter i2c-0: ioctl, cmd=0x703, arg=0x40 i2c-dev: i2c-0 writing 2 bytes. i2c-adapter i2c-0: master_xfer[0] W, addr=0x40, len=2 i2c-adapter i2c-0: i2c-algo-cpm.o: R: 0 T: 0 i2c-adapter i2c-0: cpm_iic_write(abyte=0x80) i2c-adapter i2c-0: tx sc 0 bc00 i2c-adapter i2c-0: test ready. i2c-adapter i2c-0: not ready. i2c-adapter i2c-0: Interrupt: 2 i2c-adapter i2c-0: Interrupt: 1 i2c-adapter i2c-0: test ready. i2c-adapter i2c-0: ready. i2c-adapter i2c-0: tx sc 0 3c00 i2c-dev: i2c-0 reading 1 bytes. i2c-adapter i2c-0: master_xfer[0] R, addr=0x40, len=1 i2c-adapter i2c-0: i2c-algo-cpm.o: R: 0 T: 0 i2c-adapter i2c-0: cpm_i2c_read(abyte=0x81) i2c-adapter i2c-0: test ready. i2c-adapter i2c-0: not ready. i2c-adapter i2c-0: I2C read: timeout! i2c-adapter i2c-0: cpm_i2c_force_close() i2c-dev: i2c-0 reading 1 bytes. i2c-adapter i2c-0: master_xfer[0] R, addr=0x40, len=1 i2c-adapter i2c-0: i2c-algo-cpm.o: R: 0 T: 0 i2c-adapter i2c-0: cpm_i2c_read(abyte=0x81) i2c-adapter i2c-0: test ready. i2c-adapter i2c-0: not ready. i2c-adapter i2c-0: Interrupt: 1 i2c-adapter i2c-0: test ready. i2c-adapter i2c-0: ready. i2c-adapter i2c-0: rx sc 2c00, rx sc 1800 Any ideas?
What does you chip expect? Start-Write-Start-Read-Stop or Start-Write-Stop, Start-Read-Stop? Did you try chaining the write and read request (put them into the same msg)? Thanks, Jochen