| Message ID | 20210615080553.2021061-1-piyush.mehta@xilinx.com |
|---|---|
| Headers | show |
| Series | gpio: modepin: Add driver support for modepin GPIO controller | expand |
Hi Piyush! thanks for your patch! On Tue, Jun 15, 2021 at 10:06 AM Piyush Mehta <piyush.mehta@xilinx.com> wrote: > This patch adds support for the mode pin GPIO controller. GPIO Modepin > driver set and get the value and status of the PS_MODE pin, based on > device-tree pin configuration. These 4-bits boot-mode pins are dedicated > configurable as input/output. After the stabilization of the system, > these mode pins are sampled. > > Signed-off-by: Piyush Mehta <piyush.mehta@xilinx.com> OK, sounds interesting! > +#include <linux/slab.h> I think I saw somewhere that this is not needed anymore, check if you need it. > +#define GET_OUTEN_PIN(pin) (1U << (pin)) Delete this macro and just use BIT(pin) inline. #include <linux/bits.h> > +static int modepin_gpio_get_value(struct gpio_chip *chip, unsigned int pin) > +{ > + u32 out_en; > + u32 regval = 0; > + int ret; > + > + out_en = GET_OUTEN_PIN(pin); Drop this and out_en > + ret = zynqmp_pm_bootmode_read(®val); > + if (ret) { > + pr_err("modepin: get value err %d\n", ret); > + return ret; > + } > + > + return (out_en & (regval >> 8U)) ? 1 : 0; return !!(regval & BIT(pin + 8)); should work and is easier to read IMO. We just check the right bit immediately. > +static void modepin_gpio_set_value(struct gpio_chip *chip, unsigned int pin, > + int state) > +{ > + u32 out_en; > + u32 bootpin_val = 0; > + int ret; > + > + out_en = GET_OUTEN_PIN(pin); Skip this helper variable. > + state = state != 0 ? out_en : 0; Uh that is really hard to read and modified a parameter. Skip that too. > + bootpin_val = (state << (8U)) | out_en; What you want is mask and set. bootpin_val = BIT(pin + 8); > + /* Configure bootpin value */ > + ret = zynqmp_pm_bootmode_write(bootpin_val); This just looks weird. Why are you not reading the value first since you are using read/modify/write? I *think* you want to do this: ret = zynqmp_pm_bootmode_read(&val); if (ret) /* error handling */ if (state) val |= BIT(pin + 8); else val &= ~BIT(pin + 8); ret = zynqmp_pm_bootmode_write(val); if (ret) /* error handling */ > +/* > + * modepin_gpio_dir_in - Set the direction of the specified GPIO pin as input > + * @chip: gpio_chip instance to be worked on > + * @pin: gpio pin number within the device > + * > + * Return: 0 always > + */ > +static int modepin_gpio_dir_in(struct gpio_chip *chip, unsigned int pin) > +{ > + return 0; > +} I think you said this was configurable in the commit message. Use the define GPIO_LINE_DIRECTION_OUT rather than 0. > +static int modepin_gpio_dir_out(struct gpio_chip *chip, unsigned int pin, > + int state) > +{ > + return 0; > +} Configurable? > + status = devm_gpiochip_add_data(&pdev->dev, chip, chip); > + if (status) > + dev_err_probe(&pdev->dev, status, > + "Failed to add GPIO chip\n"); just return dev_err_probe(...) Yours, Linus Walleij
Hello Linus, Thanks for the review comments. We will address all the reviews in the next version. Regards, Piyush Mehta -----Original Message----- From: Linus Walleij <linus.walleij@linaro.org> Sent: Friday, June 18, 2021 3:14 PM To: Piyush Mehta <piyushm@xilinx.com> Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>; Rob Herring <robh+dt@kernel.org>; open list:GPIO SUBSYSTEM <linux-gpio@vger.kernel.org>; open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS <devicetree@vger.kernel.org>; linux-kernel <linux-kernel@vger.kernel.org>; Linux ARM <linux-arm-kernel@lists.infradead.org>; git <git@xilinx.com>; Srinivas Goud <sgoud@xilinx.com>; Michal Simek <michals@xilinx.com> Subject: Re: [PATCH 2/2] gpio: modepin: Add driver support for modepin GPIO controller Hi Piyush! thanks for your patch! On Tue, Jun 15, 2021 at 10:06 AM Piyush Mehta <piyush.mehta@xilinx.com> wrote: > This patch adds support for the mode pin GPIO controller. GPIO Modepin > driver set and get the value and status of the PS_MODE pin, based on > device-tree pin configuration. These 4-bits boot-mode pins are > dedicated configurable as input/output. After the stabilization of the > system, these mode pins are sampled. > > Signed-off-by: Piyush Mehta <piyush.mehta@xilinx.com> OK, sounds interesting! > +#include <linux/slab.h> I think I saw somewhere that this is not needed anymore, check if you need it. > +#define GET_OUTEN_PIN(pin) (1U << (pin)) Delete this macro and just use BIT(pin) inline. #include <linux/bits.h> > +static int modepin_gpio_get_value(struct gpio_chip *chip, unsigned > +int pin) { > + u32 out_en; > + u32 regval = 0; > + int ret; > + > + out_en = GET_OUTEN_PIN(pin); Drop this and out_en > + ret = zynqmp_pm_bootmode_read(®val); > + if (ret) { > + pr_err("modepin: get value err %d\n", ret); > + return ret; > + } > + > + return (out_en & (regval >> 8U)) ? 1 : 0; return !!(regval & BIT(pin + 8)); should work and is easier to read IMO. We just check the right bit immediately. > +static void modepin_gpio_set_value(struct gpio_chip *chip, unsigned int pin, > + int state) { > + u32 out_en; > + u32 bootpin_val = 0; > + int ret; > + > + out_en = GET_OUTEN_PIN(pin); Skip this helper variable. > + state = state != 0 ? out_en : 0; Uh that is really hard to read and modified a parameter. Skip that too. > + bootpin_val = (state << (8U)) | out_en; What you want is mask and set. bootpin_val = BIT(pin + 8); > + /* Configure bootpin value */ > + ret = zynqmp_pm_bootmode_write(bootpin_val); This just looks weird. Why are you not reading the value first since you are using read/modify/write? I *think* you want to do this: ret = zynqmp_pm_bootmode_read(&val); if (ret) /* error handling */ if (state) val |= BIT(pin + 8); else val &= ~BIT(pin + 8); ret = zynqmp_pm_bootmode_write(val); if (ret) /* error handling */ > +/* > + * modepin_gpio_dir_in - Set the direction of the specified GPIO pin as input > + * @chip: gpio_chip instance to be worked on > + * @pin: gpio pin number within the device > + * > + * Return: 0 always > + */ > +static int modepin_gpio_dir_in(struct gpio_chip *chip, unsigned int > +pin) { > + return 0; > +} I think you said this was configurable in the commit message. Use the define GPIO_LINE_DIRECTION_OUT rather than 0. > +static int modepin_gpio_dir_out(struct gpio_chip *chip, unsigned int pin, > + int state) { > + return 0; > +} Configurable? > + status = devm_gpiochip_add_data(&pdev->dev, chip, chip); > + if (status) > + dev_err_probe(&pdev->dev, status, > + "Failed to add GPIO chip\n"); just return dev_err_probe(...) Yours, Linus Walleij