From patchwork Mon Jan 13 10:35:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Patrick Delaunay X-Patchwork-Id: 239560 List-Id: U-Boot discussion From: patrick.delaunay at st.com (Patrick Delaunay) Date: Mon, 13 Jan 2020 11:35:07 +0100 Subject: [PATCH v3 13/21] gpio: add support of new GPIO direction flag In-Reply-To: <20200113103515.20879-1-patrick.delaunay@st.com> References: <20200113103515.20879-1-patrick.delaunay@st.com> Message-ID: <20200113103515.20879-14-patrick.delaunay@st.com> This commit manages the new dir flags that can be used in gpio specifiers to indicate the pull-up or pull-down resistor configuration for output gpio (GPIO_PULL_UP, GPIO_PULL_DOWN) or the Open Drain/Open Source configuration for input gpio (GPIO_OPEN_DRAIN, GPIO_OPEN_SOURCE). These flags are already supported in Linux kernel in gpio lib. This patch only parse and save the direction flags in GPIO descriptor (desc->flags), it prepares the introduction of new ops to manage them. The GPIO uclass supports new GPIO flags from device-tree (GPIO_XXX define in include/dt-bindings/gpio/gpio.h) and translate them in the dir flags (GPIOD_XXX): - GPIO_PULL_UP => GPIOD_PULL_UP - GPIO_PULL_DOWN => GPIOD_PULL_DOWN - GPIO_OPEN_DRAIN => GPIOD_OPEN_DRAIN - GPIO_OPEN_SOURCE => GPIOD_OPEN_SOURCE This patch also adds protection in the check_dir_flags function for new invalid configuration of the dir flags. Signed-off-by: Patrick Delaunay Reviewed-by: Simon Glass --- This patch was part of v2 08/14 = gpio: add ops for configuration with dir flags Changes in v3: - Split the previous patch [PATCH v2 08/14] to help review Changes in v2: None drivers/gpio/gpio-uclass.c | 30 ++++++++++++++++++++++++++++++ include/asm-generic/gpio.h | 6 +++++- 2 files changed, 35 insertions(+), 1 deletion(-) diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c index 85f0b03f81..e02ef29fed 100644 --- a/drivers/gpio/gpio-uclass.c +++ b/drivers/gpio/gpio-uclass.c @@ -144,6 +144,24 @@ int gpio_xlate_offs_flags(struct udevice *dev, struct gpio_desc *desc, if (args->args[1] & GPIO_ACTIVE_LOW) desc->flags |= GPIOD_ACTIVE_LOW; + /* + * need to test 2 bits for gpio output binding: + * OPEN_DRAIN (0x6) = SINGLE_ENDED (0x2) | LINE_OPEN_DRAIN (0x4) + * OPEN_SOURCE (0x2) = SINGLE_ENDED (0x2) | LINE_OPEN_SOURCE (0x0) + */ + if (args->args[1] & GPIO_SINGLE_ENDED) { + if (args->args[1] & GPIO_LINE_OPEN_DRAIN) + desc->flags |= GPIOD_OPEN_DRAIN; + else + desc->flags |= GPIOD_OPEN_SOURCE; + } + + if (args->args[1] & GPIO_PULL_UP) + desc->flags |= GPIOD_PULL_UP; + + if (args->args[1] & GPIO_PULL_DOWN) + desc->flags |= GPIOD_PULL_DOWN; + return 0; } @@ -520,6 +538,18 @@ static int check_dir_flags(ulong flags) return -EINVAL; } + if ((flags & GPIOD_PULL_UP) && (flags & GPIOD_PULL_DOWN)) { + log_debug("%s: flags 0x%lx has GPIOD_PULL_UP and GPIOD_PULL_DOWN\n", + __func__, flags); + return -EINVAL; + } + + if ((flags & GPIOD_OPEN_DRAIN) && (flags & GPIOD_OPEN_SOURCE)) { + log_debug("%s: flags 0x%lx has GPIOD_OPEN_DRAIN and GPIOD_OPEN_SOURCE\n", + __func__, flags); + return -EINVAL; + } + return 0; } diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h index 3dd0002b0b..4f7b43f163 100644 --- a/include/asm-generic/gpio.h +++ b/include/asm-generic/gpio.h @@ -119,8 +119,12 @@ struct gpio_desc { unsigned long flags; #define GPIOD_IS_OUT BIT(1) /* GPIO is an output */ #define GPIOD_IS_IN BIT(2) /* GPIO is an input */ -#define GPIOD_ACTIVE_LOW BIT(3) /* value has active low */ +#define GPIOD_ACTIVE_LOW BIT(3) /* GPIO is active when value is low */ #define GPIOD_IS_OUT_ACTIVE BIT(4) /* set output active */ +#define GPIOD_OPEN_DRAIN BIT(5) /* GPIO is open drain type */ +#define GPIOD_OPEN_SOURCE BIT(6) /* GPIO is open source type */ +#define GPIOD_PULL_UP BIT(7) /* GPIO has pull-up enabled */ +#define GPIOD_PULL_DOWN BIT(8) /* GPIO has pull-down enabled */ uint offset; /* GPIO offset within the device */ /*