Messages in this thread | | | Date | Thu, 15 Nov 2012 09:36:57 +0100 | From | Andreas Larsson <> | Subject | Re: [PATCH v3 2/2] i2c: i2c-ocores: Add support for the GRLIB port of the controller and custom getreg and setreg functions |
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On 2012-11-13 23:45, Peter Korsgaard wrote: >>>>>> "Andreas" == Andreas Larsson <andreas@gaisler.com> writes: > > Hi, > > Andreas> The registers in the GRLIB port of the controller are 32-bit > Andreas> and in big endian byte order. The PRELOW and PREHIGH registers > Andreas> are merged into one register. The subsequent registers have > Andreas> their offset decreased accordingly. Hence the register access > Andreas> needs to be handled in a non-standard manner using custom > Andreas> getreg and setreg functions. > > Andreas> @@ -257,6 +300,14 @@ static int ocores_i2c_of_probe(struct platform_device *pdev, > > Andreas> of_property_read_u32(pdev->dev.of_node, "reg-io-width", > Andreas> &i2c->reg_io_width); > Andreas> + > Andreas> + if (of_device_is_compatible(pdev->dev.of_node, > Andreas> + "aeroflexgaisler,i2cmst")) { > Andreas> + dev_dbg(&pdev->dev, "GRLIB variant of i2c-ocores\n"); > Andreas> + i2c->setreg = oc_setreg_grlib; > Andreas> + i2c->getreg = oc_getreg_grlib; > Andreas> + } > Andreas> + > > Please also update the bindings documentation under > Documentation/devicetree/bindings/i2c.
Sure!
> With this core you need to add both aeroflexgaisler,i2cmst and > opencores,i2c-ocores to the compatible property, but the grlib variant > is NOT compatible with i2c-ocores, so that's not really nice. > > Adding a type define (TYPE_OCORES / TYPE_GRLIB) and a 2nd of_device_id > entry with .data = TYPE_GRLIB, and then using that in the probe routine > would be nicer. Have a look at i2c-at91.c for an example of a driver > doing something like that.
Yes, that is a good idea. Do you think casting to and from void * in the following solution is too ugly and rather have a struct pointed to, or do you think that would be unnecessary?
static struct of_device_id ocores_i2c_match[] = { { .compatible = "opencores,i2c-ocores", .data = (void *)TYPE_OCORES, }, { .compatible = "aeroflexgaisler,i2cmst", .data = (void *)TYPE_GRLIB, }, {}, }; MODULE_DEVICE_TABLE(of, ocores_i2c_match);
static int ocores_i2c_get_type(struct platform_device *pdev) { const struct of_device_id *match;
match = of_match_node(ocores_i2c_match, pdev->dev.of_node); if (match) return (int)match->data; else return TYPE_OCORES; }
Cheers, Andreas
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