Hi Simon,
maybe you can give me a hint on how to implement this cleanly in driver model?
To sum it up, I'd like to have a phandle pointing to *any* I2C device, not knowing which UCLASS actually fits. Then the device and the parent bus should be probed/prepared such that dm_i2c_read() can be used.
Any ideas on this?
Best regards, Philip
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On Fri, Oct 13, 2023 at 02:58:04PM +0200, Philip Oberfichtner wrote:
Hello Heiko,
On Fri, Oct 13, 2023 at 01:28:47PM +0200, Heiko Schocher wrote:
[...]
bootcount { compatible = "u-boot,bootcount-i2c"; i2c-bus = <&i2c1>; address = <0x52>;
Hmm.. do we really need this here with DTS. Why not using a phandle to a real i2c device? Something like this for example:
i2cbcdev = &i2c_rtc;with
&i2c1 { i2c_rtc: rtc@68 { [...]
and so there is no need for knowing the bus and address ...
Yeah I agree that would be much better, but ...
[...]
when you use a phandle, you can replace the part from reading "offset" with this:
uclass_get_device_by_phandle(UCLASS_I2C, dev, "i2cbcdev", &priv->bcdev);
of course plus error checking...
This does not work, UCLASS_I2C is used for the *bus above* the device we actually want.
Next thing I thougt about: Why not use the UCLASS_I2C_GENERIC. But this expects a "i2c-chip" compatible string, which our rtc or whatever device obviously does not have.
I think using UCLASS_I2C_GENERIC might indeed be the best approach. Maybe using something like 'device_bind_driver()'. But again, this expects the parent device to be there already as far as I can tell.
Any suggestions?
Best regards, Philip
- return 0;
+}
+static const struct bootcount_ops bootcount_i2c_ops = {
- .get = bootcount_i2c_get,
- .set = bootcount_i2c_set,
+};
+static const struct udevice_id bootcount_i2c_ids[] = {
- { .compatible = "u-boot,bootcount-i2c" },
- { }
+};
+U_BOOT_DRIVER(bootcount_i2c) = {
- .name = "bootcount-i2c",
- .id = UCLASS_BOOTCOUNT,
- .priv_auto = sizeof(struct bootcount_i2c_priv),
- .probe = bootcount_i2c_probe,
- .of_match = bootcount_i2c_ids,
- .ops = &bootcount_i2c_ops,
+};
bye, Heiko -- DENX Software Engineering GmbH, Managing Director: Erika Unter HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: +49-8142-66989-52 Fax: +49-8142-66989-80 Email: hs@denx.de