On Sat, May 13, 2017 at 10:29 AM, Jan Kiszka <jan.kiszka@xxxxxxxxxxx> wrote:
> On the SIMATIC, IOT2040 only a single pin is exportable as GPIO, the
> rest is required to operate the UART. To allow modeling this case,
> use device properties to specify a (consecutive) pin subset for
> exporting by the gpio-exar driver.
> @@ -123,6 +132,7 @@ static int gpio_exar_probe(struct platform_device *pdev)
> struct exar_gpio_chip *exar_gpio;
> void __iomem *p;
> int index, ret;
> + u32 val;
>
> if (pcidev->vendor != PCI_VENDOR_ID_EXAR)
> return -ENODEV;
> @@ -152,9 +162,12 @@ static int gpio_exar_probe(struct platform_device *pdev)
> exar_gpio->gpio_chip.get = exar_get_value;
> exar_gpio->gpio_chip.set = exar_set_value;
> exar_gpio->gpio_chip.base = -1;
> - exar_gpio->gpio_chip.ngpio = 16;
> + device_property_read_u32(&pdev->dev, "ngpio", &val);
> + exar_gpio->gpio_chip.ngpio = val;
You have to check return code, otherwise you might end up with
uninitialized data.
> exar_gpio->regs = p;
> exar_gpio->index = index;
> + device_property_read_u32(&pdev->dev, "first_gpio", &val);
> + exar_gpio->first_gpio = val;
Ditto.
> #include <linux/string.h>
> #include <linux/tty.h>
> #include <linux/8250_pci.h>
> +#include <linux/property.h>
Alphabetical order, please.
> static void *
> -xr17v35x_register_gpio(struct pci_dev *pcidev)
> +xr17v35x_register_gpio(struct pci_dev *pcidev, unsigned int first_gpio,
> + unsigned int ngpio)
> {
> + struct property_entry properties[] = {
> + PROPERTY_ENTRY_U32("first_gpio", first_gpio),
This should be documented in device tree bindings, otherwise it's a
linux software hook and I'm not sure it's the best what we can do
here.
> + PROPERTY_ENTRY_U32("ngpio", ngpio),
This should be a registered property name (I see "ngpios" in the bindings).
> + { }
> + };
> struct platform_device *pdev;
>
> pdev = platform_device_alloc("gpio_exar", PLATFORM_DEVID_AUTO);
> /*
> - * platform_device_add_data kmemdups the data, therefore we can safely
> - * pass a stack reference.
> + * platform_device_add_data and platform_device_add_properties copy
> + * the data, therefore we can safely pass a stack references.
> */
Can you formulate this in an order to reduce ping-ponging lines across
the series?
--
With Best Regards,
Andy Shevchenko
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