| Message ID | 1509396602-1936-3-git-send-email-timur@codeaurora.org (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | Andy Gross |
| Headers | show |
On Mon, 2017-10-30 at 15:50 -0500, Timur Tabi wrote: > Add support for specifying that some GPIOs within a range are > unavailable. > Some systems have a sparse list of GPIOs, where a range of GPIOs is > specified (usually 0 to n-1), but some subset within that range is > absent or unavailable for whatever reason. > > To support this, allow drivers to specify a bitmask of GPIOs that > are present or absent. Gpiolib will then block access to those that > are absent. > > Signed-off-by: Timur Tabi <timur@codeaurora.org> > > > static int gpiochip_irqchip_init_valid_mask(struct gpio_chip > *gpiochip) > { Instead of mangling this function wouldn't be better to introduce a separate one for line and perhaps a third one which calls them both? > - if (!gpiochip->irq_need_valid_mask) > - return 0; > + if (gpiochip->irq_need_valid_mask) { > + gpiochip->irq_valid_mask = > + kcalloc(BITS_TO_LONGS(gpiochip->ngpio), > + sizeof(long), GFP_KERNEL); > + if (!gpiochip->irq_valid_mask) > + return -ENOMEM; > > - gpiochip->irq_valid_mask = kcalloc(BITS_TO_LONGS(gpiochip- > >ngpio), > - sizeof(long), GFP_KERNEL); > - if (!gpiochip->irq_valid_mask) > - return -ENOMEM; > + /* Assume by default all GPIOs are valid */ > + bitmap_fill(gpiochip->irq_valid_mask, gpiochip- > >ngpio); > + } > > - /* Assume by default all GPIOs are valid */ > - bitmap_fill(gpiochip->irq_valid_mask, gpiochip->ngpio); > + if (gpiochip->line_need_valid_mask) { > + gpiochip->line_valid_mask = > + kcalloc(BITS_TO_LONGS(gpiochip->ngpio), > + sizeof(long), GFP_KERNEL); > + if (!gpiochip->line_valid_mask) > + return -ENOMEM; > + > + /* Assume by default all GPIOs are valid */ > + bitmap_fill(gpiochip->line_valid_mask, gpiochip- > >ngpio); > + } > > return 0; > } ...for my opinion it will drastically increase readability and reduce diff as well (better for review).
On 10/31/2017 04:12 AM, Andy Shevchenko wrote: > Instead of mangling this function wouldn't be better to introduce a > separate one for line and perhaps a third one which calls them both? The diff is convoluted, but the end result is clean: static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip) { if (gpiochip->irq_need_valid_mask) { gpiochip->irq_valid_mask = kcalloc(BITS_TO_LONGS(gpiochip->ngpio), sizeof(long), GFP_KERNEL); if (!gpiochip->irq_valid_mask) return -ENOMEM; /* Assume by default all GPIOs are valid */ bitmap_fill(gpiochip->irq_valid_mask, gpiochip->ngpio); } if (gpiochip->line_need_valid_mask) { gpiochip->line_valid_mask = kcalloc(BITS_TO_LONGS(gpiochip->ngpio), sizeof(long), GFP_KERNEL); if (!gpiochip->line_valid_mask) return -ENOMEM; /* Assume by default all GPIOs are valid */ bitmap_fill(gpiochip->line_valid_mask, gpiochip->ngpio); } return 0; } Is this acceptable?
On Tue, 2017-10-31 at 13:54 -0500, Timur Tabi wrote: > On 10/31/2017 04:12 AM, Andy Shevchenko wrote: > > Instead of mangling this function wouldn't be better to introduce a > > separate one for line and perhaps a third one which calls them both? > > The diff is convoluted, but the end result is clean: > Is this acceptable? I also put in the comment the following: --- 8< --- 8< --- 8< --- ...for my opinion it will drastically increase readability and reduce diff as well (better for review). --- 8< --- 8< --- 8< --- The decision is up to Linus. I simple shared my opinion.
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 60553af4c004..c32387936cdd 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1481,22 +1481,36 @@ static struct gpio_chip *find_chip_by_name(const char *name) static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip) { - if (!gpiochip->irq_need_valid_mask) - return 0; + if (gpiochip->irq_need_valid_mask) { + gpiochip->irq_valid_mask = + kcalloc(BITS_TO_LONGS(gpiochip->ngpio), + sizeof(long), GFP_KERNEL); + if (!gpiochip->irq_valid_mask) + return -ENOMEM; - gpiochip->irq_valid_mask = kcalloc(BITS_TO_LONGS(gpiochip->ngpio), - sizeof(long), GFP_KERNEL); - if (!gpiochip->irq_valid_mask) - return -ENOMEM; + /* Assume by default all GPIOs are valid */ + bitmap_fill(gpiochip->irq_valid_mask, gpiochip->ngpio); + } - /* Assume by default all GPIOs are valid */ - bitmap_fill(gpiochip->irq_valid_mask, gpiochip->ngpio); + if (gpiochip->line_need_valid_mask) { + gpiochip->line_valid_mask = + kcalloc(BITS_TO_LONGS(gpiochip->ngpio), + sizeof(long), GFP_KERNEL); + if (!gpiochip->line_valid_mask) + return -ENOMEM; + + /* Assume by default all GPIOs are valid */ + bitmap_fill(gpiochip->line_valid_mask, gpiochip->ngpio); + } return 0; } static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip) { + kfree(gpiochip->line_valid_mask); + gpiochip->line_valid_mask = NULL; + kfree(gpiochip->irq_valid_mask); gpiochip->irq_valid_mask = NULL; } @@ -1510,6 +1524,15 @@ static bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip, return test_bit(offset, gpiochip->irq_valid_mask); } +static bool gpiochip_irqchip_line_valid(const struct gpio_chip *gpiochip, + unsigned int offset) +{ + /* No mask means all valid */ + if (likely(!gpiochip->line_valid_mask)) + return true; + return test_bit(offset, gpiochip->line_valid_mask); +} + /** * gpiochip_set_cascaded_irqchip() - connects a cascaded irqchip to a gpiochip * @gpiochip: the gpiochip to set the irqchip chain to @@ -3320,6 +3343,10 @@ struct gpio_desc *__must_check gpiod_get_index(struct device *dev, return desc; } + /* Make sure the GPIO is valid before we request it. */ + if (!gpiochip_irqchip_line_valid(desc->gdev->chip, idx)) + return ERR_PTR(-EACCES); + status = gpiod_request(desc, con_id); if (status < 0) return ERR_PTR(status); diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index c97f8325e8bf..83df2934bdf7 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -172,6 +172,8 @@ struct gpio_chip { bool irq_nested; bool irq_need_valid_mask; unsigned long *irq_valid_mask; + bool line_need_valid_mask; + unsigned long *line_valid_mask; struct lock_class_key *lock_key; #endif
Add support for specifying that some GPIOs within a range are unavailable. Some systems have a sparse list of GPIOs, where a range of GPIOs is specified (usually 0 to n-1), but some subset within that range is absent or unavailable for whatever reason. To support this, allow drivers to specify a bitmask of GPIOs that are present or absent. Gpiolib will then block access to those that are absent. Signed-off-by: Timur Tabi <timur@codeaurora.org> --- drivers/gpio/gpiolib.c | 43 +++++++++++++++++++++++++++++++++++-------- include/linux/gpio/driver.h | 2 ++ 2 files changed, 37 insertions(+), 8 deletions(-)