Messages in this thread | | | Subject | Re: [PATCH 1/1] pinctrl: stmfx: add irq_request/release_resources callbacks | From | Amelie DELAUNAY <> | Date | Mon, 7 Oct 2019 16:53:09 +0200 |
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Hi Linus,
On 10/5/19 6:49 PM, Linus Walleij wrote: > On Fri, Oct 4, 2019 at 2:29 PM Amelie Delaunay <amelie.delaunay@st.com> > wrote: > >> When an STMFX IO is used as interrupt through the interrupt-controller >> binding, the STMFX driver should configure this IO as input. Default >> value of STMFX IO direction is input, but if the IO is used as output >> before the interrupt use, it will not work without these callbacks. >> >> Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com> > > OK I see what you want to achieve. > >> +static int stmfx_gpio_irq_request_resources(struct irq_data *data) >> +{ >> + struct gpio_chip *gpio_chip = irq_data_get_irq_chip_data(data); >> + struct stmfx_pinctrl *pctl = gpiochip_get_data(gpio_chip); >> + int ret; >> + >> + ret = stmfx_gpio_direction_input(&pctl->gpio_chip, data->hwirq); >> + if (ret) >> + return ret; >> + >> + ret = gpiochip_lock_as_irq(&pctl->gpio_chip, data->hwirq); >> + if (ret) { >> + dev_err(pctl->dev, "Unable to lock gpio %lu as IRQ: %d\n", >> + data->hwirq, ret); >> + return ret; >> + } >> + >> + return 0; >> +} > > Just call gpiochip_reqres_irq() instead of calling the lock etc > explicitly. > >> +static void stmfx_gpio_irq_release_resources(struct irq_data *data) >> +{ >> + struct gpio_chip *gpio_chip = irq_data_get_irq_chip_data(data); >> + struct stmfx_pinctrl *pctl = gpiochip_get_data(gpio_chip); >> + >> + gpiochip_unlock_as_irq(&pctl->gpio_chip, data->hwirq); >> +} > > Just call gpiochip_relres_irq() > > But all this duplicated a lot of code from the core which is not so nice. > >> @@ -678,6 +706,8 @@ static int stmfx_pinctrl_probe(struct platform_device *pdev) >> pctl->irq_chip.irq_set_type = stmfx_pinctrl_irq_set_type; >> pctl->irq_chip.irq_bus_lock = stmfx_pinctrl_irq_bus_lock; >> pctl->irq_chip.irq_bus_sync_unlock = stmfx_pinctrl_irq_bus_sync_unlock; >> + pctl->irq_chip.irq_request_resources = stmfx_gpio_irq_request_resources; >> + pctl->irq_chip.irq_release_resources = stmfx_gpio_irq_release_resources; > > What about just adding > > pctl->irq_chip.irq_enable and do stmfx_gpio_direction_input() > in that callback instead? gpiolib will helpfully wrap it.
Thanks for pointing that out to me.
I can't use .irq_enable because of I2C transfer to set gpio direction (scheduling while atomic BUG occurs in this case). Indeed, .irq_enable is called under raw_spin_lock_irqsave in __setup_irq() while irq_request_resources is called before.
I could apply gpio direction in stmfx_pinctrl_irq_bus_sync_unlock depending on pctl->irq_gpi_src[] (checking which one is set, to set input direction), but this will be applied each time a consumer requests a stmfx gpio irq.
IMHO, keeping .irq_request/release_resources callbacks and using gpiochip_reqres_irq()/gpiochip_relres_irq() seems to be the best compromise.
Regards, Amelie
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