Messages in this thread | | | From | Andy Shevchenko <> | Date | Sat, 13 May 2017 16:50:02 +0300 | Subject | Re: [PATCH 7/8] gpio-exar/8250-exar: Make set of exported GPIOs configurable |
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On Sat, May 13, 2017 at 10:29 AM, Jan Kiszka <jan.kiszka@siemens.com> 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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