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    SubjectRe: [PATCH 20/20] pinctrl: Enhance mapping table to support pin config operations
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    On Mon, Feb 20, 2012 at 7:46 AM, Stephen Warren <swarren@nvidia.com> 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>

    Overall excellent, just smaller things below:

    > @@ -817,7 +827,40 @@ it even more compact which assumes you want to use pinctrl-foo and position
    >  0 for mapping, for example:
    >
    >  static struct pinctrl_map __initdata mapping[] = {
    > -       PIN_MAP("default", "pinctrl-foo", "i2c0", "foo-i2c.0"),
    > +       PIN_MAP_MUX_GROUP("foo-i2c.o", "default", "pinctrl-foo", NULL, "i2c0"),
    > +};

    OK looks good!

    > +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 buy this too...

    > +Finally, some devices expect the mapping table to contain certain specific
    > +named states. When running on hardware that doesn't need any pin controller
    > +configuration, the mapping table must still contain those named states, in
    > +order to explicitly indicate that the states were provided and intended to
    > +be empty. Table entry macro PIN_MAP_DUMMY_STATE serves the purpose of defining
    > +a named state without causing any pin controller to be programmed:
    > +
    > +static struct pinctrl_map __initdata mapping[] = {
    > +       PIN_MAP_DUMMY_STATE("foo-i2c.0", "default"),
    >  };

    Looks useful so why not.

    > @@ -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")
    > +PIN_MAP_MUX_GROUP("pinctrl-foo", "active", "pinctrl-foo", NULL, "power_func")

    Please keep the explicit _HOG macros for readability. Relying on
    the implicit relation between dev and pctldev being the same and to be
    parsed by humans is vulnerable.

    PIN_MAP_MUX_GROUP_HOG()

    in this case, with the same arguments (though with PINCTRL_STATE_DEFAULT
    in place for "active") is better IMO.

    >  /* Pinmux settings */
    >  static struct pinctrl_map __initdata u300_pinmux_map[] = {
    >        /* anonymous maps for chip power and EMIFs */
    > -       PIN_MAP_SYS_HOG("default", "pinmux-u300", "power"),
    > -       PIN_MAP_SYS_HOG("default", "pinmux-u300", "emif0"),
    > -       PIN_MAP_SYS_HOG("default", "pinmux-u300", "emif1"),
    > +       PIN_MAP_MUX_GROUP("pinmux-u300", "default", "pinmux-u300", NULL, "power"),
    > +       PIN_MAP_MUX_GROUP("pinmux-u300", "default", "pinmux-u300", NULL, "emif0"),
    > +       PIN_MAP_MUX_GROUP("pinmux-u300", "default", "pinmux-u300", NULL, "emif1"),
    >        /* per-device maps for MMC/SD, SPI and UART */
    > -       PIN_MAP("default", "pinmux-u300", "mmc0", "mmci"),
    > -       PIN_MAP("default", "pinmux-u300", "spi0", "pl022"),
    > -       PIN_MAP("default", "pinmux-u300", "uart0", "uart0"),
    > +       PIN_MAP_MUX_GROUP("mmci",  "default", "pinmux-u300", NULL, "mmc0"),
    > +       PIN_MAP_MUX_GROUP("pl022", "default", "pinmux-u300", NULL, "spi0"),
    > +       PIN_MAP_MUX_GROUP("uart0", "default", "pinmux-u300", NULL, "uart0"),
    >  };

    PIN_MAP_MUX_GROUP_HOG() please. PINCTRL_STATE_DEFAULT instead
    of "default".

    Or maybe we should imply that PIN_MAP_MUX_GROUP_HOG() hogs the
    default state, or have PIN_MAP_MUX_GROUP_HOG_DEFAULT() even?

    > --- a/drivers/pinctrl/core.c
    > +++ b/drivers/pinctrl/core.c
    > @@ -341,6 +341,31 @@ int pinctrl_get_group_selector(struct pinctrl_dev *pctldev,
    >  }
    >
    >  /**
    > + * pinctrl_get_pin_id() - returns the group selector for a group
    > + * @pctldev: the pin controller handling the group
    > + * @pin_group: the pin group to look up

    This kerneldoc is wrong... pin, not group.

    > + */
    > +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;
    > +               }
    > +       }

    (...)

    >        /* First sanity check the new mapping */
    >        for (i = 0; i < num_maps; i++) {
    > +               if (!maps[i].dev_name) {
    > +                       pr_err("failed to register map %s (%d): no device given\n",
    > +                              maps[i].name, i);
    > +                       return -EINVAL;
    > +               }
    > +

    Hm should this not be done earlier in the patch series?

    > +       /*
    > +        * FIXME: We should really get the pin controler to dump the config
    > +        * values, so they can be decoded to something meaningful.
    > +        */
    > +       for (i = 0; i < setting->data.configs.num_configs; i++)
    > +               seq_printf(s, " %08lx", setting->data.configs.configs[i]);
    > +
    > +       seq_printf(s, "\n");
    > +}

    Per-device config print function? But no need to rush that.

    Apart from this I mostly just trust this patch, like the previous one.

    Yours,
    Linus Walleij
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