Hi Mike, Thanks for the reply, I'll give this a go.
- Martin. On Sat, Dec 1, 2018 at 10:01 AM Mike Looijmans <mike.looijm...@topic.nl> wrote: > One thing you may want to try is replace the cadence I2C driver with the > generic bit-bang GPIO driver (on the same pins). > > Example devicetree that does this in the kernel (you'll need to activate > the bitbang gpio i2c driver in the kernel config though): > > https://github.com/topic-embedded-products/linux/blob/topic-miami/arch/arm/boot/dts/topic-miami.dtsi#L52 > > We have had lots of troubles with the I2C controller in the Zynq, it > appears to be broken, and replacing the driver with a bitbang GPIO one > solved all issues. In our case, the problem was with longer transfers > like sending EDID tables to video encoder chips, but we've seen > occasional failures on simple transfers (eeprom, hw monitors, etc) as well. > > > > On 30-11-18 19:47, Martin Townsend wrote: > > Hi, > > > > We are in the process of upgrading to Sumo which has the 4.14 > > linux-xlnx kernel and everything is working fine except for our > > LTC-3375 regulator device driver which was working fine with the 4.9 > > kernel but with the newer kernel we are getting the following in the > > log. > > > > SW1: failed to get the current voltage(-6) > > ltc3375 6-0034: failed to register regulator SW1: -6 > > > > We get this message twice as there are 2 LTC-3375 on different > > channels of the PCA9548, here's a cut down version of the device tree: > > > > &i2c0 { > > status = "okay"; > > /* clock-frequency = <400000>; */ > > clock-frequency = <100000>; > > pinctrl-names = "default"; > > pinctrl-0 = <&pinctrl_i2c0_default>; > > > > > > /* I2C Switch */ > > i2cswitch@70 { > > compatible = "nxp,pca9548"; > > #address-cells = <1>; > > #size-cells = <0>; > > reg = <0x70>; > > > > /* PS Power Switcher */ > > i2c@4 { > > #address-cells = <1>; > > #size-cells = <0>; > > reg = <4>; > > > > powerswitcher1@34 { > > compatible = "ltc,ltc3375"; > > reg = <0x34>; > > interrupt-parent = <&gpiom2>; > > interrupts = <12 1>; > > > > regulators { > > sw1 { > > regulator-min-microvolt = <693987>; > > regulator-max-microvolt = <1306329>; > > lltc,fb-voltage-divider = <100000 158000>; > > regulator-ramp-delay = <7000>; > > regulator-boot-on; > > regulator-always-on; > > }; > > sw2 { > > ... > > }; > > sw3 { > > ... > > }; > > sw4 { > > ... > > }; > > sw5 { > > ... > > }; > > sw6 { > > ... > > }; > > sw7 { > > ... > > }; > > sw8 { > > ... > > }; > > }; > > }; > > }; > > > > /* PL Power Switcher */ > > i2c@5 { > > #address-cells = <1>; > > #size-cells = <0>; > > reg = <5>; > > > > powerswitcher1@34 { > > compatible = "ltc,ltc3375"; > > reg = <0x34>; > > interrupt-parent = <&gpiom2>; > > interrupts = <13 1>; > > > > regulators { > > sw1 { > > regulator-min-microvolt = <693987>; > > regulator-max-microvolt = <1306329>; > > lltc,fb-voltage-divider = <100000 158000>; > > regulator-ramp-delay = <7000>; > > regulator-boot-on; > > regulator-always-on; > > }; > > sw2 { > > ... > > }; > > sw3 { > > ... > > }; > > sw4 { > > ... > > }; > > sw5 { > > ... > > }; > > sw6 { > > ... > > }; > > sw7 { > > ... > > }; > > sw8 { > > ... > > }; > > }; > > }; > > }; > > }; > > }; > > > > I traced the -6 error code (-ENXIO) to the cadence driver where it > > basically receives a NAK. > > > > static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg > *msgs, > > int num) > > { > > ... > > /* Process the msg one by one */ > > for (count = 0; count < num; count++, msgs++) { > > if (count == (num - 1)) > > id->bus_hold_flag = 0; > > > > ret = cdns_i2c_process_msg(id, msgs, adap); > > if (ret) > > goto out; > > > > /* Report the other error interrupts to application */ > > if (id->err_status) { > > cdns_i2c_master_reset(adap); > > > > if (id->err_status & CDNS_I2C_IXR_NACK) { > > ret = -ENXIO; > > goto out; > > } > > ret = -EIO; > > goto out; > > } > > } > > } > > > > After debugging further I can see that it's trying to select the right > > channel of the PCA9548 but the i2c controller on the Xilinx is failing > > with a NAK. So it's not even getting as far as the LTC driver. Here > > is some of my debug that shows it's the PCA9548 that is failing as > > this is address 0x70 whereas the LTC is at 0x34 > > > > pca954x_select_chan: chan:4 regval:10 > > pca954x_reg_write: addr:70 val:10 > > cdns-i2c e0004000.i2c: cdns_i2c_master_xfer: id->err_status=4 > > cdns-i2c e0004000.i2c: cdns_i2c_master_xfer: id->p_msg->addr=70 > > > > I've done a diff between the 4.9 and 4.14 kernel but can't see any > > obvious in either of these drivers. I've checked the device tree in > > this area but again can see no changes. The second I2C interface is > > working fine, I2C1. > > > > I did a dump_stack on the i2c read that was failing > > [<c010e854>] (unwind_backtrace) from [<c010aa68>] (show_stack+0x10/0x14) > > [<c010aa68>] (show_stack) from [<c064a3e8>] (dump_stack+0x80/0xa0) > > [<c064a3e8>] (dump_stack) from [<c04a2e50>] > (cdns_i2c_master_xfer+0x2fc/0x3e4) > > [<c04a2e50>] (cdns_i2c_master_xfer) from [<c049e908>] > > (_i2c_transfer+0x1cc/0x20c) > > [<c049e908>] (_i2c_transfer) from [<c04a38dc>] > (pca954x_reg_write+0x4c/0x8c) > > [<c04a38dc>] (pca954x_reg_write) from [<c04a3990>] > > (pca954x_select_chan+0x44/0x5c) > > [<c04a3990>] (pca954x_select_chan) from [<c04a1548>] > > (_i2c_mux_master_xfer+0x28/0x64) > > [<c04a1548>] (_i2c_mux_master_xfer) from [<c049e908>] > > (_i2c_transfer+0x1cc/0x20c) > > [<c049e908>] (_i2c_transfer) from [<c049e9d4>] (i2c_transfer+0x8c/0xac) > > [<c049e9d4>] (i2c_transfer) from [<c03d553c>] (regmap_i2c_read+0x48/0x64) > > [<c03d553c>] (regmap_i2c_read) from [<c03d29fc>] > (regmap_raw_read+0x84/0xd0) > > [<c03d29fc>] (_regmap_raw_read) from [<c03d2a70>] > (_regmap_bus_read+0x28/0x48) > > [<c03d2a70>] (_regmap_bus_read) from [<c03d2504>] > (_regmap_read+0x84/0xac) > > [<c03d2504>] (_regmap_read) from [<c03d256c>] (regmap_read+0x40/0x58) > > [<c03d256c>] (regmap_read) from [<c0364bec>] > > (regulator_get_voltage_sel_regmap+0x1c/0x50) > > [<c0364bec>] (regulator_get_voltage_sel_regmap) from [<bf0472a8>] > > (ltc3375_get_voltage_sel_regmap+0xc/0x4c [oina_regulator_ltc3375]) > > [<bf0472a8>] (ltc3375_get_voltage_sel_regmap [oina_regulator_ltc3375]) > > from [<c0361a10>] (_regulator_get_voltage+0x8c/0x128) > > [<c0361a10>] (_regulator_get_voltage) from [<c03637f4>] > > (regulator_register+0x3ec/0xb60) > > [<c03637f4>] (regulator_register) from [<bf0475a4>] > > (ltc3375_probe+0x2bc/0x394 [oina_regulator_ltc3375]) > > [<bf0475a4>] (ltc3375_probe [regulator_ltc3375]) from [<c049e3d0>] > > (i2c_device_probe+0x22c/0x244) > > > > I'll look into the regulator_register code next but was just wondering > > if anyone else has seen this or if anyone knows if there's a fix > > available for this? > > > > Any help appreciated, > > > > Cheers, > > Martin > > > > > -- > Mike Looijmans > -- > _______________________________________________ > meta-xilinx mailing list > meta-xilinx@yoctoproject.org > https://lists.yoctoproject.org/listinfo/meta-xilinx >
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