This driver adds pinctrl/GPIO support for Intel Emmitsburg PCH. The
GPIO controller is based on the next generation GPIO hardware but still
compatible with the one supported by the Intel core pinctrl/GPIO driver.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Some of the pin names were provided officially to the customers
in different spelling. We update pin names in accordance with
the official list.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
The pins on the Bay Trail SoC have separate input-buffer and output-buffer
enable bits and a read of the level bit of the value register will always
return the value from the input-buffer.
The BIOS of a device may configure a pin in output-only mode, only enabling
the output buffer, and write 1 to the level bit to drive the pin high.
This 1 written to the level bit will be stored inside the data-latch of the
output buffer.
But a subsequent read of the value register will return 0 for the level bit
because the input-buffer is disabled. This causes a read-modify-write as
done by byt_gpio_set_direction() to write 0 to the level bit, driving the
pin low!
Before this commit byt_gpio_direction_output() relied on
pinctrl_gpio_direction_output() to set the direction, followed by a call
to byt_gpio_set() to apply the selected value. This causes the pin to
go low between the pinctrl_gpio_direction_output() and byt_gpio_set()
calls.
Change byt_gpio_direction_output() to directly make the register
modifications itself instead. Replacing the 2 subsequent writes to the
value register with a single write.
Note that the pinctrl code does not keep track internally of the direction,
so not going through pinctrl_gpio_direction_output() is not an issue.
This issue was noticed on a Trekstor SurfTab Twin 10.1. When the panel is
already on at boot (no external monitor connected), then the i915 driver
does a gpiod_get(..., GPIOD_OUT_HIGH) for the panel-enable GPIO. The
temporarily going low of that GPIO was causing the panel to reset itself
after which it would not show an image until it was turned off and back on
again (until a full modeset was done on it). This commit fixes this.
This commit also updates the byt_gpio_direction_input() to use direct
register accesses instead of going through pinctrl_gpio_direction_input(),
to keep it consistent with byt_gpio_direction_output().
Note for backporting, this commit depends on:
commit e2b74419e5 ("pinctrl: baytrail: Replace WARN with dev_info_once
when setting direct-irq pin to output")
Cc: stable@vger.kernel.org
Fixes: 86e3ef812f ("pinctrl: baytrail: Update gpio chip operations")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Protect IO in intel_gpio_get_direction(), intel_gpio_community_irq_handler(),
intel_config_get_debounce() and intel_config_get_pull() by lock. Even for
simple readl() we better serialize IO to avoid potential problems.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Split intel_config_get() to three functions, i.e. intel_config_get() and
two helpers intel_config_get_pull() and intel_config_get_debounce() to be
symmetrical with intel_config_set*().
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Drop the only label in the code, i.e. in intel_config_set_debounce(),
for consistency with the rest. In entire driver we use multipoint
return.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Instead of using bitwise operations against returned values,
which is a bit fragile, convert IRQ handler to count amount of
GPIO groups, where at least one interrupt happened, and convert
it to returned value by IRQ_RETVAL() macro.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
It's possible scenario that pin has been in different mode, while
the respective GPIO register has a leftover output buffer enabled.
In such case when we request GPIO it will switch to GPIO mode, and
thus to output with unknown value, followed by switching to input
mode. This can produce a glitch on the pin.
Disable input and output buffer when switching to GPIO to avoid
potential glitches.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
We have some data structures duplicated across the drivers.
Let's deduplicate them by using struct intel_pinctrl_soc_data,
struct intel_community and struct intel_pinctrl_context that
are being provided by pinctrl-intel.h.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Individual drivers may install ACPI OpRegion handlers based on
address space ID which differs from community to community.
Add special field in the struct intel_community for that purpose.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
It's common across the drivers to use the (pin_base, npins) pair to describe
community characteristics. Thus, move them in the struct intel_community
to be closer to each other.
While at it, add a blank line to cut driver usable fields from what core
reserves for itself.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
