Re: [PATCH v3 1/2] gpio: designware: switch device node to fwnode

Jiang Qiu
2016-02-25T11:58:45Z

在 2016/2/24 21:46, Andy Shevchenko 写道:
> On Wed, Feb 24, 2016 at 2:33 PM, qiujiang <qiujiang@huawei.com> wrote:
>> This patch switch device node to fwnode in dwapb_port_property,
>> so as to apply a unified data structure for DT and ACPI.
>>
>> This change also needs to be done in intel_quark_i2c_gpio driver,
>> since it depends on gpio-dwapb driver.
>>
>> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
>> Signed-off-by: qiujiang <qiujiang@huawei.com>
>
> Yes, something like this.
> Though I have questions:
> - why do you use fwnode_*() instead of device_property_*() calls?
> What prevents us to move to device property API directly?
Yes, it looks more reasonable by using devce_property. Howerver,
device_get_child_node_count was used here to find each child node. This
API output the fwnode_handle for each child node directly, but device
property APIs need 'dev' data instead. Actually, the effects of fwnode_*()
and device_*() are the same. So, I used fwnode_*() APIs here.

If there is any other more way to traverse child nodes, let me know.
Thank you.
>
>> - gpio->domain = irq_domain_add_linear(node, ngpio,
>> - &irq_generic_chip_ops, gpio);
>> + gpio->domain = irq_domain_create_linear(fwnode, ngpio,
>> + &irq_generic_chip_ops, gpio);
>
> Are they equivalent?
Yes, they are equivalent.
>
>> @@ -415,7 +415,7 @@ static int dwapb_gpio_add_port(struct dwapb_gpio *gpio,
>> }
>>
>> #ifdef CONFIG_OF_GPIO
>> - port->gc.of_node = pp->node;
>> + port->gc.of_node = to_of_node(pp->fwnode);
>
> If fwnode is not OF one?
> Perhaps, something like ... = is_of_node() ? to_of_node() : NULL;
>
The way you suggested is more resonable, I will fixed it in next version.
>
>> - node = dev->of_node;
>> - if (!IS_ENABLED(CONFIG_OF_GPIO) || !node)
>> + if (!IS_ENABLED(CONFIG_OF_GPIO) || !(dev->of_node))
>> return ERR_PTR(-ENODEV);
>
> So, since you converted to fwnode, do you still need this check?
>
Although this patch coverted device node to fwnode, only DTs binding was
supported here, and patch2 support ACPI will remove this check.
>>
>> - nports = of_get_child_count(node);
>> + nports = device_get_child_node_count(dev);
>> if (nports == 0)
>> return ERR_PTR(-ENODEV);
>
> ...I think this one fail if it will not found any child.
This one fail? yes, it will return to failure.
I am not very clear here.
>
>> - if (of_property_read_u32(port_np, "reg", &pp->idx) ||
>> + if (fwnode_property_read_u32(fwnode, "reg", &pp->idx) ||
>
> device_property_*() ?
>
>> pp->idx >= DWAPB_MAX_PORTS) {
>> dev_err(dev, "missing/invalid port index for %s\n",
>> - port_np->full_name);
>> + to_of_node(fwnode)->full_name);
>
> If it's not OF?
This is checked above, and patch2 will remove it.
>
>> - if (of_property_read_u32(port_np, "snps,nr-gpios",
>> + if (fwnode_property_read_u32(fwnode, "snps,nr-gpios",
>
> Ditto.
>
>> &pp->ngpio)) {
>> dev_info(dev, "failed to get number of gpios for %s\n",
>> - port_np->full_name);
>> + to_of_node(fwnode)->full_name);
>
> Ditto.
>
>> if (pp->idx == 0 &&
>> - of_property_read_bool(port_np, "interrupt-controller")) {
>> - pp->irq = irq_of_parse_and_map(port_np, 0);
>> + of_property_read_bool(to_of_node(fwnode),
>> + "interrupt-controller")) {
>
> device_property_*() ?
>
>> + pp->irq = irq_of_parse_and_map(to_of_node(fwnode), 0);
>> if (!pp->irq) {
>> dev_warn(dev, "no irq for bank %s\n",
>> - port_np->full_name);
>> + to_of_node(fwnode)->full_name);
>> }
>> }
>>
>> pp->irq_shared = false;
>> pp->gpio_base = -1;
>> - pp->name = port_np->full_name;
>> + pp->name = to_of_node(fwnode)->full_name;
>> }
>>
>> return pdata;
>
>