[RFC PATCH v1 06/20] gpio: Add set_input and polling interface to GPIO lib code
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STALE1825d
REVIEWED: 1 (0M)
From: <hidden>
Date: 2021-08-24 16:48:34
Also in:
linux-gpio
Subsystem:
gpio subsystem, gpio uapi, the rest · Maintainers:
Linus Walleij, Bartosz Golaszewski, Linus Torvalds
1 review trailer.
From: Lakshmi Sowjanya D <redacted> Some Intel Timed I/O devices do not implement IRQ functionality. Augment read() interface to allow polling. Move input setup functionality to a separate function simplifying linereq_create() to add output code in subsequent commit. Co-developed-by: Christopher Hall <redacted> Signed-off-by: Christopher Hall <redacted> Signed-off-by: Tamal Saha <redacted> Signed-off-by: Lakshmi Sowjanya D <redacted> Reviewed-by: Mark Gross <redacted> --- drivers/gpio/gpiolib-cdev.c | 52 +++++++++++++++++++++++++++++++++---- 1 file changed, 47 insertions(+), 5 deletions(-)
diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index 4741bf34750b..cb6b9155884c 100644
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c@@ -1331,6 +1331,52 @@ static const struct file_operations line_fileops = { #endif }; +static int setup_input(struct linereq *lr, struct gpio_v2_line_config *lc, + u32 line_no, unsigned int offset, u32 lflags) +{ + int err, ret; + + /* Only one bias flag can be set. */ + if (((lflags & GPIO_V2_LINE_FLAG_BIAS_DISABLED) && + (lflags & (GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN | + GPIO_V2_LINE_FLAG_BIAS_PULL_UP))) || + ((lflags & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN) && + (lflags & GPIO_V2_LINE_FLAG_BIAS_PULL_UP))) + return -EINVAL; + + if (lflags & GPIO_V2_LINE_FLAG_ACTIVE_LOW) + set_bit(FLAG_ACTIVE_LOW, &lr->lines[line_no].desc->flags); + if (lflags & GPIO_V2_LINE_FLAG_BIAS_DISABLED) + set_bit(FLAG_BIAS_DISABLE, &lr->lines[line_no].desc->flags); + if (lflags & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN) + set_bit(FLAG_PULL_DOWN, &lr->lines[line_no].desc->flags); + if (lflags & GPIO_V2_LINE_FLAG_BIAS_PULL_UP) + set_bit(FLAG_PULL_UP, &lr->lines[line_no].desc->flags); + + err = gpiod_direction_input(lr->lines[line_no].desc); + if (err) + return err; + + ret = edge_detector_setup(&lr->lines[line_no], lc, line_no, + lflags & GPIO_V2_LINE_EDGE_FLAGS); + if (ret < 0) { + if (ret != -ENXIO) { + if (lr->gdev->chip->setup_poll && + lr->gdev->chip->setup_poll(lr->gdev->chip, offset, + &lflags) == 0 && + lr->gdev->chip->do_poll) + ret = 0; + else + return -ENODEV; + } else { + return -ENODEV; + } + } + + lr->lines[line_no].eflags = lflags; + return ret; +} + static int linereq_create(struct gpio_device *gdev, void __user *ip) { struct gpio_v2_line_request ulr;
@@ -1423,12 +1469,8 @@ static int linereq_create(struct gpio_device *gdev, void __user *ip) if (ret) goto out_free_linereq; } else if (flags & GPIO_V2_LINE_FLAG_INPUT) { - ret = gpiod_direction_input(desc); - if (ret) - goto out_free_linereq; + ret = setup_input(lr, lc, i, offset, flags); - ret = edge_detector_setup(&lr->lines[i], lc, i, - flags & GPIO_V2_LINE_EDGE_FLAGS); if (ret) goto out_free_linereq; }
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2.17.1