Messages in this thread | | | Date | Tue, 28 Feb 2012 11:41:30 +0800 | From | Dong Aisheng <> | Subject | Re: [PATCH 20/20] pinctrl: Enhance mapping table to support pin config operations |
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On Mon, Feb 27, 2012 at 11:02:01AM -0800, Stephen Warren wrote: > Dong Aisheng wrote at Monday, February 27, 2012 5:21 AM: > > On Sun, Feb 19, 2012 at 11:46:00PM -0700, Stephen Warren wrote: > > > The pinctrl mapping table can now contain entries to: > > > * Set the mux function of a pin group > > > * Apply a set of pin config options to a pin or a group > > > > > > This allows pinctrl_select_state() to apply pin configs settings as well > > > as mux settings. > > > > > > Signed-off-by: Stephen Warren <swarren@nvidia.com> > ... > > > +The mapping table may also contain pin configuration entries. It's common for > > > +each pin/group to have a number of configuration entries that affect it, so > > > +the table entries for configuration reference an array of config parameters > > > +and values. An example using the convenience macros is shown below: > > > + > > > +static unsigned long i2c_grp_configs[] = { > > > + FOO_PIN_DRIVEN, > > > + FOO_PIN_PULLUP, > > > +}; > > > + > > > +static unsigned long i2c_pin_configs[] = { > > > + FOO_OPEN_COLLECTOR, > > > + FOO_SLEW_RATE_SLOW, > > > +}; > > > + > > > +static struct pinctrl_map __initdata mapping[] = { > > > + PIN_MAP_MUX_GROUP("foo-i2c.0", "default", "pinctrl-foo", "i2c0", "i2c0"), > > > + PIN_MAP_MUX_CONFIGS_GROUP("foo-i2c.0", "default", "pinctrl-foo", "i2c0", i2c_grp_configs), > > > + PIN_MAP_MUX_CONFIGS_PIN("foo-i2c.0", "default", "pinctrl-foo", "i2c0scl", i2c_pin_configs), > > > + PIN_MAP_MUX_CONFIGS_PIN("foo-i2c.0", "default", "pinctrl-foo", "i2c0sda", i2c_pin_configs), > > > > I still have not read all over this patch. > > But one question i'm considering is that > > will this way here also work for "virtual" group? > > For example, the virtual group "i2c_grp_configs" may actually contains > > the config for each pin in that group? > > The core will handle this difference or let each driver to handle it? > > Since the core has no knowledge of virtual groups, everything has to be > handled inside the pin controller driver: When the core asks the driver > to enumerate the groups it supports, those virtual groups must be included > in the list. The mapping table may contain entries to configure those > virtual groups, which will be passed on to the driver to implement as it > sees fit. So, in short, yes, I believe this handles virtual groups just > fine. > Ok, great.
> > > @@ -1022,7 +1074,7 @@ Since it may be common to request the core to hog a few always-applicable > > > mux settings on the primary pin controller, there is a convenience macro for > > > this: > > > > > > -PIN_MAP_SYS_HOG("active", "pinctrl-foo", "power_func") > > > > Hmm? > > Why remove this one? > > In the patch I posted, I simplified the mapping table macros by replacing > all mux entries with a single macro PIN_MAP_MUX_GROUP(). However, I've > since modified the patch to include a number of special-case macros, so > this macro has been added back (albeit under a slightly different name). > Sounds good.
> > > +int pinctrl_get_pin_id(struct pinctrl_dev *pctldev, > > > + const char *pin) > > > +{ > > > + unsigned int i; > > > + > > > + for (i = 0; i < pctldev->desc->npins; i++) { > > > + if (pctldev->desc->pins[i].name == NULL) > > > + continue; > > > + if (!strcmp(pin, pctldev->desc->pins[i].name)) { > > > + dev_dbg(pctldev->dev, "found pin id %u for %s\n", > > > + i, pin); > > > + return i; > > > > It looks actually this is not a PIN id. > > It's just the index of the pin array. > > Pin has its own id: > > struct pinctrl_pin_desc { > > unsigned number; > > const char *name; > > }; > > I guess I should just delete this function and call pin_get_from_name() > instead. > > However, this does raise one question: > > Right now, pin_config_set() calls pin_get_from_name() to find the pin > ID of a pin. This returns that "number" field in the struct above. This > is then passed to the pin controller driver's pin_config_set() callback. > Hence, the pin ID value passed to pin_config_set() can't be used to index > into the driver's own pin_desc array if the pin numbers are sparse. Is > that intended? I suppose it's OK since any driver-specific information > about each pin can't be stored in the pin_desc array anyway, since that > array has a standard type without space for driver-specific data, and > any driver-specific array would probably be indexed by the values in the > .number field, not the pin_desc array index. It's indeed.
Regards Dong Aisheng
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