On Thu, Nov 15, 2018 at 2:32 PM Florian Eckert <fe@xxxxxxxxxx> wrote: > Add a new device driver "gpio-apu" which will handle the GPIOs on APU2 > and APU3 devices from PC Engines. > > APU2 (https://pcengines.ch/schema/apu2c.pdf page 7): > - G32 is "button_reset" connected to the smd-button on the frontpanel > - G50 is "mpcie2_reset" connected to mPCIe2 reset line > - G51 is "mpcie3_reset" connected to mPCIe3 reset line > > APU3 (https://pcengines.ch/schema/apu3c.pdf page 7): > - G32 is "button_reset" connected to the smd-button on the frontpanel > - G50 is "mpcie2_reset" connected to mPCIe2 reset line > - G51 is "mpcie3_reset" connected to mPCIe3 reset line > - G33 is "simswap" connected to SIM switch IC to swap the SIM between > mPCIe2 and mPCIe3 slot > > Signed-off-by: Florian Eckert <fe@xxxxxxxxxx> This is looking better and better! Thanks to everyone helping out and thanks for your perseverance Florian! > +config GPIO_APU > + tristate "PC Engines APU2/APU3 GPIO support" > + depends on X86 > + select GPIO_GENERIC Excellent idea. But it seems you are not using this. You would be using it if you used bgpio_init() but if I understand correctly this driver cannot use that because this GPIO is something like one register per pin, correct? Let me suggest: > +struct apu_gpio_pdata { > + struct platform_device *pdev; > + struct gpio_chip *chip; Make that a real member of this struct and not a pointer. I.e. just remove the "*". > +static struct apu_gpio_pdata *apu_gpio; Why a static local? It seems you can just pass around the pointer. > +static int gpio_apu_get_dir(struct gpio_chip *chip, unsigned int offset) > +{ > + u32 val; > + > + spin_lock(&apu_gpio->lock); > + > + val = ~ioread32(apu_gpio->addr[offset]); > + val = (val >> APU_GPIO_BIT_DIR) & 1; I would just: #include <linux/bits.h> val = ~ioread32(apu_gpio->addr[offset]); spin_unlock(); return !!(val & BIT(APU_GPIO_BIT_DIR)); This clamps the value to [0,1] in a nice way. > +static int gpio_apu_get_data(struct gpio_chip *chip, unsigned int offset) > +{ > + u32 val; > + > + spin_lock(&apu_gpio->lock); > + > + val = ioread32(apu_gpio->addr[offset]); > + > + spin_unlock(&apu_gpio->lock); > + > + return (val >> APU_GPIO_BIT_RD) & 1; return !!(val & BIT(APU_GPIO_BIT_RD)); > + return devm_gpiochip_add_data(&pdev->dev, apu_gpio->chip, NULL); Instead of passing NULL pas apu_gpio as the last argument and in all callbacks you can use: struct apu_gpio_pdata *apu_gpio = gpiochip_get_data(gc); To get a pointer to the per-instance state container. Yours, Linus Walleij
