[RFC PATCH v2 2/4] pinctrl: imx: add pinmux imx driver

[Dong Aisheng-B29396]

Hi Grant,

> -----Original Message-----
> From: glikely at secretlab.ca [mailto:glikely at secretlab.ca] On Behalf Of
> Grant Likely
> Sent: Thursday, December 15, 2011 5:47 AM
> To: Linus Walleij
> Cc: Dong Aisheng-B29396; linux-kernel at vger.kernel.org; linux-arm-
> kernel at lists.infradead.org; linus.walleij at stericsson.com;
> s.hauer at pengutronix.de; Guo Shawn-R65073; kernel at pengutronix.de;
> rob.herring at calxeda.com
> Subject: Re: [RFC PATCH v2 2/4] pinctrl: imx: add pinmux imx driver
> Importance: High
> 
> On Wed, Dec 14, 2011 at 11:00 AM, Linus Walleij <linus.walleij at linaro.org>
> wrote:
> > On Wed, Dec 14, 2011 at 5:03 PM, Dong Aisheng <b29396 at freescale.com>
> wrote:
> >
> >> The driver contains the initial support for imx53 and imx6q.
> >
> > Cool! Comments below...
> >
> >> --- /dev/null
> >> +++ b/drivers/pinctrl/pinmux-imx-core.c
> >
> > We should start naming these pinctrl-* rather than pinmux-* so just
> > rename it.
> >
> > Until here it looks like business as usual..
> >
> >> +#ifdef CONFIG_OF
> >> +static int __devinit imx_pmx_parse_functions(struct device_node *np,
> >> +                       struct imx_pinctrl_info *info, u32 num) {
> >> +       struct imx_pmx_func *function;
> >> +       struct imx_pin_group *group;
> >> +       int ret, len;
> >> +
> >> +       dev_dbg(info->dev, "parse function %d\n", num);
> >> +
> >> +       group = &info->groups[num];
> >> +       function = &info->functions[num];
> >> +
> >> +       /* Initialise group */
> >> +       ret = of_property_read_string(np, "grp_name", &group->name);
> >> +       if (ret) {
> >> +               dev_err(info->dev, "failed to get grp_name\n");
> >> +               return ret;
> >> +       }
> >> +
> >> +       ret = of_property_read_u32(np, "num_pins", &group->num_pins);
> >> +       if (ret) {
> >> +               dev_err(info->dev, "failed to get num_pins\n");
> >> +               return ret;
> >> +       }
> >> +
> >> +       ret = of_property_read_u32(np, "num_mux", &group->num_mux);
> >> +       if (ret) {
> >> +               dev_err(info->dev, "failed to get num_mux\n");
> >> +               return ret;
> >> +       }
> >> +
> >> +       if (group->num_pins != group->num_mux)
> >> +               return -EINVAL;
> >> +
> >> +       group->pins = devm_kzalloc(info->dev, group->num_pins *
> >> + sizeof(unsigned int),
> >> +                               GFP_KERNEL);
> >> +       group->mux_mode = devm_kzalloc(info->dev, group->num_mux *
> >> + sizeof(unsigned int),
> >> +                               GFP_KERNEL);
> >> +       if (!group->pins || !group->mux_mode)
> >> +               return -ENOMEM;
> >> +
> >> +       /* sanity check */
> >> +       if (of_get_property(np, "grp_pins", &len) &&
> >> +               len != group->num_pins * sizeof(unsigned int)) {
> >> +               dev_err(info->dev, "wrong pins number?\n");
> >> +               return -EINVAL;
> >> +       }
> >> +
> >> +       if (of_get_property(np, "grp_mux", &len) &&
> >> +               len != group->num_mux * sizeof(unsigned int)) {
> >> +               dev_err(info->dev, "wrong pin mux number?\n");
> >> +               return -EINVAL;
> >> +       }
> >> +
> >> +       ret = of_property_read_u32_array(np, "grp_pins",
> >> +                       group->pins, group->num_pins);
> >> +       if (ret) {
> >> +               dev_err(info->dev, "failed to get grp_pins\n");
> >> +               return ret;
> >> +       }
> >> +
> >> +       ret = of_property_read_u32_array(np, "grp_mux",
> >> +                       group->mux_mode, group->num_mux);
> >> +       if (ret) {
> >> +               dev_err(info->dev, "failed to get grp_mux\n");
> >> +               return ret;
> >> +       }
> >> +
> >> +       /* Initialise function */
> >> +       ret = of_property_read_string(np, "func_name",
> >> + &function->name);
> >> +       if (ret) {
> >> +               dev_err(info->dev, "failed to get func_name\n");
> >> +               return ret;
> >> +       }
> >> +
> >> +       function->groups = devm_kzalloc(info->dev, sizeof(char **),
> >> + GFP_KERNEL);
> >> +       function->num_groups = 1;
> >> +       function->groups[0] = group->name;
> >> +
> >> +       dev_dbg(info->dev, "func_name %s grp_name %s num_groups
> >> + %d\n",
> >> +                               function->name, function->groups[0],
> >> +                               function->num_groups);
> >> +
> >> +       return 0;
> >> +}
> >> +
> >> +static int __devinit imx_pmx_probe_dt(struct platform_device *pdev,
> >> +                               struct imx_pinctrl_info *info) {
> >> +       struct device_node *np = pdev->dev.of_node;
> >> +       struct device_node *child = NULL;
> >> +       int ret, i;
> >> +       u32 nfuncs = 0;
> >> +
> >> +       if (!np)
> >> +               return -ENODEV;
> >> +
> >> +       nfuncs = of_get_child_number(np);
> >> +       if (nfuncs <= 0) {
> >> +               dev_err(&pdev->dev, "no functions defined\n");
> >> +               return -EINVAL;
> >> +       }
> >> +
> >> +       info->nfunctions = nfuncs;
> >> +       info->functions = devm_kzalloc(&pdev->dev, nfuncs *
> >> + sizeof(struct imx_pmx_func),
> >> +                                       GFP_KERNEL);
> >> +       if (!info->functions)
> >> +               return -ENOMEM;
> >> +
> >> +       /* DT file only passes one group per one function */
> >> +       info->ngroups = nfuncs;
> >> +       info->groups = devm_kzalloc(&pdev->dev, nfuncs *
> >> + sizeof(struct imx_pin_group),
> >> +                                       GFP_KERNEL);
> >> +       if (!info->groups)
> >> +               return -ENOMEM;
> >> +
> >> +       child = NULL;
> >> +       i = 0;
> >> +       for_each_child_of_node(np, child) {
> >> +               ret = imx_pmx_parse_functions(child, info, i++);
> >> +               if (ret) {
> >> +                       dev_err(&pdev->dev, "failed to parse
> >> + function\n");
> >> +                       return ret;
> >> +               }
> >> +       }
> >> +
> >> +       return 0;
> >> +}
> >> +#else
> >> +static int __devinit imx_pmx_probe_dt(struct platform_device *pdev,
> >> +                               struct imx_pinctrl_info *info) {
> >> +       return -ENODEV;
> >> +}
> >> +#endif
> >
> > Looks clever to me! And I think we have agreed that this probing must
> > be inside each driver.
> >
> > Can we have a look at the corresponding device tree?
> 
> ... and binding documentation.  While on that topic, the convention is
> for property names to use dash '-' characters, not underscores '_'.
> The properties I see here are using the later.
> 
Yes, will follow the convention and add binding doc.
Thanks for your suggestion.

Regards
Dong Aisheng