| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <d4624a94-7a09-e28a-30bb-5d0e367722c0@baylibre.com>
Date: Fri, 20 Jan 2017 10:24:08 +0100
From: Neil Armstrong <narmstrong@...libre.com>
To: Linus Walleij <linus.walleij@...aro.org>,
Mika Westerberg <mika.westerberg@...ux.intel.com>
Cc: Alexandre Courbot <gnurou@...il.com>,
Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
"linux-gpio@...r.kernel.org" <linux-gpio@...r.kernel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 3/3] pinctrl / gpio: Introduce .set_config() callback for
GPIO chips
On 01/20/2017 10:13 AM, Linus Walleij wrote:
> On Thu, Jan 19, 2017 at 10:48 AM, Mika Westerberg
> <mika.westerberg@...ux.intel.com> wrote:
>
>> Currently we already have two pin configuration related callbacks
>> available for GPIO chips .set_single_ended() and .set_debounce(). In
>> future we expect to have even more, which does not scale well if we need
>> to add yet another callback to the GPIO chip structure for each possible
>> configuration parameter.
>>
>> Better solution is to reuse what we already have available in the
>> generic pinconf.
>>
>> To support this, we introduce a new .set_config() callback for GPIO
>> chips. The callback takes a single packed pin configuration value as
>> parameter. This can then be extended easily beyond what is currently
>> supported by just adding new types to the generic pinconf enum.
>>
>> We then convert the existing drivers over .set_config() and finally
>> remove the .set_single_ended() and .set_debounce() callbacks.
>>
>> Suggested-by: Linus Walleij <linus.walleij@...aro.org>
>> Signed-off-by: Mika Westerberg <mika.westerberg@...ux.intel.com>
>
> Yes!!! This is exactly how this should be done.
>
> Can't wait to apply the final version of this.
>
>> +static int gpio_set_drive_mode(struct gpio_chip *gc, unsigned offset,
>> + enum pin_config_param mode)
>> +{
>> + unsigned long config = { PIN_CONF_PACKED(mode, 0) };
>> +
>> + return gc->set_config ? gc->set_config(gc, offset, config) : -ENOTSUPP;
>> +}
>
> I would name it gpio_set_drive_single_ended() as the open source/open
> drain is all we support here.
>
>> if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
>> /* First see if we can enable open drain in hardware */
>> - if (gc->set_single_ended) {
>> - ret = gc->set_single_ended(gc, gpio_chip_hwgpio(desc),
>> - LINE_MODE_OPEN_DRAIN);
>> - if (!ret)
>> - goto set_output_value;
>> - }
>> + ret = gpio_set_drive_mode(gc, gpio_chip_hwgpio(desc),
>> + PIN_CONFIG_DRIVE_OPEN_DRAIN);
>> + if (!ret)
>> + goto set_output_value;
>
> Aha I see, so if we fail to set single ended we get to the next step.
> Nice.
>
>> /* Emulate open drain by not actively driving the line high */
>> if (val)
>> return gpiod_direction_input(desc);
>> }
>
> (...)
>
>> - if (gc->set_single_ended) {
>> - ret = gc->set_single_ended(gc, gpio_chip_hwgpio(desc),
>> - LINE_MODE_OPEN_SOURCE);
>> - if (!ret)
>> - goto set_output_value;
>> - }
>> + ret = gpio_set_drive_mode(gc, gpio_chip_hwgpio(desc),
>> + PIN_CONFIG_DRIVE_OPEN_SOURCE);
>> /* Emulate open source by not actively driving the line low */
>> if (!val)
>> return gpiod_direction_input(desc);
>
> But here the handling seems to be wrong? You still need
> the if (!ret) goto set_output_value?
>
>> } else {
>> - /* Make sure to disable open drain/source hardware, if any */
>> - if (gc->set_single_ended)
>> - gc->set_single_ended(gc,
>> - gpio_chip_hwgpio(desc),
>> - LINE_MODE_PUSH_PULL);
>> + gpio_set_drive_mode(gc, gpio_chip_hwgpio(desc),
>> + PIN_CONFIG_DRIVE_PUSH_PULL);
>
> Nice.
>
>> -static int sx150x_gpio_set_single_ended(struct gpio_chip *chip,
>> - unsigned int offset,
>> - enum single_ended_mode mode)
>> +static int sx150x_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
>> + unsigned long config)
>> {
>> - struct sx150x_pinctrl *pctl = gpiochip_get_data(chip);
>> - int ret;
>> -
>> - switch (mode) {
>> - case LINE_MODE_PUSH_PULL:
>> - if (pctl->data->model != SX150X_789 ||
>> - sx150x_pin_is_oscio(pctl, offset))
>> - return 0;
>> -
>> - ret = regmap_write_bits(pctl->regmap,
>> - pctl->data->pri.x789.reg_drain,
>> - BIT(offset), 0);
>> - break;
>> -
>> - case LINE_MODE_OPEN_DRAIN:
>> - if (pctl->data->model != SX150X_789 ||
>> - sx150x_pin_is_oscio(pctl, offset))
>> - return -ENOTSUPP;
>> -
>> - ret = regmap_write_bits(pctl->regmap,
>> - pctl->data->pri.x789.reg_drain,
>> - BIT(offset), BIT(offset));
>> - break;
>> - default:
>> - ret = -ENOTSUPP;
>> - break;
>> - }
>> -
>> - return ret;
>> + return pinctrl_gpio_set_config(chip->base + offset, config);
>> }
>
> This is the beauty of it all..
It would be even cooler it this becomes a generic helper !
>
>> @@ -811,16 +782,26 @@ static int sx150x_pinconf_set(struct pinctrl_dev *pctldev, unsigned int pin,
>> break;
>>
>> case PIN_CONFIG_DRIVE_OPEN_DRAIN:
>> - ret = sx150x_gpio_set_single_ended(&pctl->gpio,
>> - pin, LINE_MODE_OPEN_DRAIN);
>> + if (pctl->data->model != SX150X_789 ||
>> + sx150x_pin_is_oscio(pctl, pin))
>> + return -ENOTSUPP;
>> +
>> + ret = regmap_write_bits(pctl->regmap,
>> + pctl->data->pri.x789.reg_drain,
>> + BIT(pin), BIT(pin));
>> if (ret < 0)
>> return ret;
>>
>> break;
>>
>> case PIN_CONFIG_DRIVE_PUSH_PULL:
>> - ret = sx150x_gpio_set_single_ended(&pctl->gpio,
>> - pin, LINE_MODE_PUSH_PULL);
>> + if (pctl->data->model != SX150X_789 ||
>> + sx150x_pin_is_oscio(pctl, pin))
>> + return 0;
>> +
>> + ret = regmap_write_bits(pctl->regmap,
>> + pctl->data->pri.x789.reg_drain,
>> + BIT(pin), 0);
>> if (ret < 0)
>> return ret;
>>
>> @@ -1178,7 +1159,7 @@ static int sx150x_probe(struct i2c_client *client,
>> pctl->gpio.direction_output = sx150x_gpio_direction_output;
>> pctl->gpio.get = sx150x_gpio_get;
>> pctl->gpio.set = sx150x_gpio_set;
>> - pctl->gpio.set_single_ended = sx150x_gpio_set_single_ended;
>> + pctl->gpio.set_config = sx150x_gpio_set_config;
>
> Would be nice if some SX150x person could look at this but it seems just
> right to me.
Seems good, please CC us in v2 so we can add a Tested-by.
Thanks,
Neil
>
>> diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
>> index c2748accea71..2939c1d84add 100644
>> --- a/include/linux/gpio/driver.h
>> +++ b/include/linux/gpio/driver.h
>> @@ -8,6 +8,7 @@
>> #include <linux/irqdomain.h>
>> #include <linux/lockdep.h>
>> #include <linux/pinctrl/pinctrl.h>
>> +#include <linux/pinctrl/pinconf-generic.h>
>
> Yups there is lands...
>
> Thanks, I'm impressed.
>
> Hope I'll be able to apply v2.
>
> Yours,
> Linus Walleij
>
Powered by blists - more mailing lists