Merge tag 'gpio-v4.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

Pull GPIO updates from Linus Walleij:
 "This is the bulk of GPIO changes for kernel cycle v4.7:

  Core infrastructural changes:

   - Support for natively single-ended GPIO driver stages.

     This means that if the hardware has registers to configure open
     drain or open source configuration, we use that rather than (as we
     did before) try to emulate it by switching the line to an input to
     get high impedance.

     This is also documented throughly in Documentation/gpio/driver.txt
     for those of you who did not understand one word of what I just
     wrote.

   - Start to do away with the unnecessarily complex and unitelligible
     ARCH_REQUIRE_GPIOLIB and ARCH_WANT_OPTIONAL_GPIOLIB, another
     evolutional artifact from the time when the GPIO subsystem was
     unmaintained.

     Archs can now just select GPIOLIB and be done with it, cleanups to
     arches will trickle in for the next kernel.  Some minor archs ACKed
     the changes immediately so these are included in this pull request.

   - Advancing the use of the data pointer inside the GPIO device for
     storing driver data by switching the PowerPC, Super-H Unicore and
     a few other subarches or subsystem drivers in ALSA SoC, Input,
     serial, SSB, staging etc to use it.

   - The initialization now reads the input/output state of the GPIO
     lines, so that each GPIO descriptor knows - if this callback is
     implemented - whether the line is input or output.  This also
     reflects nicely in userspace "lsgpio".

   - It is now possible to name GPIO producer names, line names, from
     the device tree.  (Platform data has been supported for a while).
     I bet we will get a similar mechanism for ACPI one of those days.
     This makes is possible to get sensible producer names for e.g.
     GPIO rails in "lsgpio" in userspace.

  New drivers:

   - New driver for the Loongson1.

   - The XLP driver now supports Broadcom Vulcan ARM64.

   - The IT87 driver now supports IT8620 and IT8628.

   - The PCA953X driver now supports Galileo Gen2.

  Driver improvements:

   - MCP23S08 was switched to use the gpiolib irqchip helpers and now
     also suppors level-triggered interrupts.

   - 74x164 and RCAR now supports the .set_multiple() callback

   - AMDPT was converted to use generic GPIO.

   - TC3589x, TPS65218, SX150X, F7188X, MENZ127, VX855, WM831X, WM8994
     support the new single ended callback for open drain and in some
     cases open source.

   - Implement the .get_direction() callback for a few more drivers like
     PL061, Xgene.

  Cleanups:

   - Paul Gortmaker combed through the drivers and de-modularized those
     who are not really modules.

   - Move the GPIO poweroff DT bindings to the power subdir where they
     belong.

   - Rename gpio-generic.c to gpio-mmio.c, which is much more to the
     point.  That's what it is handling, nothing more, nothing less"

* tag 'gpio-v4.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (126 commits)
  MIPS: do away with ARCH_[WANT_OPTIONAL|REQUIRE]_GPIOLIB
  gpio: zevio: make it explicitly non-modular
  gpio: timberdale: make it explicitly non-modular
  gpio: stmpe: make it explicitly non-modular
  gpio: sodaville: make it explicitly non-modular
  pinctrl: sh-pfc: Let gpio_chip.to_irq() return zero on error
  gpio: dwapb: Add ACPI device ID for DWAPB GPIO controller on X-Gene platforms
  gpio: dt-bindings: add wd,mbl-gpio bindings
  gpio: of: make it possible to name GPIO lines
  gpio: make gpiod_to_irq() return negative for NO_IRQ
  gpio: xgene: implement .get_direction()
  gpio: xgene: Enable ACPI support for X-Gene GFC GPIO driver
  gpio: tegra: Implement gpio_get_direction callback
  gpio: set up initial state from .get_direction()
  gpio: rename gpio-generic.c into gpio-mmio.c
  gpio: generic: fix GPIO_GENERIC_PLATFORM is set to module case
  gpio: dwapb: add gpio-signaled acpi event support
  gpio: dwapb: convert device node to fwnode
  gpio: dwapb: remove name from dwapb_port_property
  gpio/qoriq: select IRQ_DOMAIN
  ...

1 files changed, 91 insertions, 42 deletions

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index b747c76fd2b1..d407f904a31c 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -622,14 +622,31 @@ int gpiochip_add_data(struct gpio_chip *chip, void *data)
                 struct gpio_desc *desc = &gdev->descs[i];
 
                 desc->gdev = gdev;
-
-                /* REVISIT: most hardware initializes GPIOs as inputs (often
-                 * with pullups enabled) so power usage is minimized. Linux
-                 * code should set the gpio direction first thing; but until
-                 * it does, and in case chip->get_direction is not set, we may
-                 * expose the wrong direction in sysfs.
+                /*
+                 * REVISIT: most hardware initializes GPIOs as inputs
+                 * (often with pullups enabled) so power usage is
+                 * minimized. Linux code should set the gpio direction
+                 * first thing; but until it does, and in case
+                 * chip->get_direction is not set, we may expose the
+                 * wrong direction in sysfs.
                  */
-                desc->flags = !chip->direction_input ? (1 << FLAG_IS_OUT) : 0;
+
+                if (chip->get_direction) {
+                        /*
+                         * If we have .get_direction, set up the initial
+                         * direction flag from the hardware.
+                         */
+                        int dir = chip->get_direction(chip, i);
+
+                        if (!dir)
+                                set_bit(FLAG_IS_OUT, &desc->flags);
+                } else if (!chip->direction_input) {
+                        /*
+                         * If the chip lacks the .direction_input callback
+                         * we logically assume all lines are outputs.
+                         */
+                        set_bit(FLAG_IS_OUT, &desc->flags);
+                }
         }
 
         spin_unlock_irqrestore(&gpio_lock, flags);
@@ -1547,8 +1564,8 @@ EXPORT_SYMBOL_GPL(gpiod_direction_input);
 
 static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
 {
-        struct gpio_chip        *chip;
-        int                     status = -EINVAL;
+        struct gpio_chip *gc = desc->gdev->chip;
+        int ret;
 
         /* GPIOs used for IRQs shall not be set as output */
         if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
@@ -1558,28 +1575,50 @@ static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
                 return -EIO;
         }
 
-        /* Open drain pin should not be driven to 1 */
-        if (value && test_bit(FLAG_OPEN_DRAIN,  &desc->flags))
-                return gpiod_direction_input(desc);
-
-        /* Open source pin should not be driven to 0 */
-        if (!value && test_bit(FLAG_OPEN_SOURCE,  &desc->flags))
-                return gpiod_direction_input(desc);
+        if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
+                /* First see if we can enable open drain in hardware */
+                if (gc->set_single_ended) {
+                        ret = gc->set_single_ended(gc, gpio_chip_hwgpio(desc),
+                                                   LINE_MODE_OPEN_DRAIN);
+                        if (!ret)
+                                goto set_output_value;
+                }
+                /* Emulate open drain by not actively driving the line high */
+                if (value)
+                        return gpiod_direction_input(desc);
+        }
+        else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
+                if (gc->set_single_ended) {
+                        ret = gc->set_single_ended(gc, gpio_chip_hwgpio(desc),
+                                                   LINE_MODE_OPEN_SOURCE);
+                        if (!ret)
+                                goto set_output_value;
+                }
+                /* Emulate open source by not actively driving the line low */
+                if (!value)
+                        return gpiod_direction_input(desc);
+        } else {
+                /* Make sure to disable open drain/source hardware, if any */
+                if (gc->set_single_ended)
+                        gc->set_single_ended(gc,
+                                             gpio_chip_hwgpio(desc),
+                                             LINE_MODE_PUSH_PULL);
+        }
 
-        chip = desc->gdev->chip;
-        if (!chip->set || !chip->direction_output) {
+set_output_value:
+        if (!gc->set || !gc->direction_output) {
                 gpiod_warn(desc,
                        "%s: missing set() or direction_output() operations\n",
                        __func__);
                 return -EIO;
         }
 
-        status = chip->direction_output(chip, gpio_chip_hwgpio(desc), value);
-        if (status == 0)
+        ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), value);
+        if (!ret)
                 set_bit(FLAG_IS_OUT, &desc->flags);
         trace_gpio_value(desc_to_gpio(desc), 0, value);
-        trace_gpio_direction(desc_to_gpio(desc), 0, status);
-        return status;
+        trace_gpio_direction(desc_to_gpio(desc), 0, ret);
+        return ret;
 }
 
 /**
@@ -1841,10 +1880,10 @@ static void gpio_chip_set_multiple(struct gpio_chip *chip,
         }
 }
 
-static void gpiod_set_array_value_priv(bool raw, bool can_sleep,
-                                       unsigned int array_size,
-                                       struct gpio_desc **desc_array,
-                                       int *value_array)
+void gpiod_set_array_value_complex(bool raw, bool can_sleep,
+                                   unsigned int array_size,
+                                   struct gpio_desc **desc_array,
+                                   int *value_array)
 {
         int i = 0;
 
@@ -1950,8 +1989,8 @@ void gpiod_set_raw_array_value(unsigned int array_size,
 {
         if (!desc_array)
                 return;
-        gpiod_set_array_value_priv(true, false, array_size, desc_array,
-                                   value_array);
+        gpiod_set_array_value_complex(true, false, array_size, desc_array,
+                                      value_array);
 }
 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
 
@@ -1972,8 +2011,8 @@ void gpiod_set_array_value(unsigned int array_size,
 {
         if (!desc_array)
                 return;
-        gpiod_set_array_value_priv(false, false, array_size, desc_array,
-                                   value_array);
+        gpiod_set_array_value_complex(false, false, array_size, desc_array,
+                                      value_array);
 }
 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
 
@@ -1998,13 +2037,22 @@ EXPORT_SYMBOL_GPL(gpiod_cansleep);
  */
 int gpiod_to_irq(const struct gpio_desc *desc)
 {
-        struct gpio_chip        *chip;
-        int                     offset;
+        struct gpio_chip *chip;
+        int offset;
 
         VALIDATE_DESC(desc);
         chip = desc->gdev->chip;
         offset = gpio_chip_hwgpio(desc);
-        return chip->to_irq ? chip->to_irq(chip, offset) : -ENXIO;
+        if (chip->to_irq) {
+                int retirq = chip->to_irq(chip, offset);
+
+                /* Zero means NO_IRQ */
+                if (!retirq)
+                        return -ENXIO;
+
+                return retirq;
+        }
+        return -ENXIO;
 }
 EXPORT_SYMBOL_GPL(gpiod_to_irq);
 
@@ -2176,8 +2224,8 @@ void gpiod_set_raw_array_value_cansleep(unsigned int array_size,
         might_sleep_if(extra_checks);
         if (!desc_array)
                 return;
-        gpiod_set_array_value_priv(true, true, array_size, desc_array,
-                                   value_array);
+        gpiod_set_array_value_complex(true, true, array_size, desc_array,
+                                      value_array);
 }
 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
 
@@ -2199,8 +2247,8 @@ void gpiod_set_array_value_cansleep(unsigned int array_size,
         might_sleep_if(extra_checks);
         if (!desc_array)
                 return;
-        gpiod_set_array_value_priv(false, true, array_size, desc_array,
-                                   value_array);
+        gpiod_set_array_value_complex(false, true, array_size, desc_array,
+                                      value_array);
 }
 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
 
@@ -2726,15 +2774,16 @@ int gpiod_hog(struct gpio_desc *desc, const char *name,
 
         local_desc = gpiochip_request_own_desc(chip, hwnum, name);
         if (IS_ERR(local_desc)) {
-                pr_err("requesting hog GPIO %s (chip %s, offset %d) failed\n",
-                       name, chip->label, hwnum);
-                return PTR_ERR(local_desc);
+                status = PTR_ERR(local_desc);
+                pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
+                       name, chip->label, hwnum, status);
+                return status;
         }
 
         status = gpiod_configure_flags(desc, name, dflags);
         if (status < 0) {
-                pr_err("setup of hog GPIO %s (chip %s, offset %d) failed\n",
-                       name, chip->label, hwnum);
+                pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
+                       name, chip->label, hwnum, status);
                 gpiochip_free_own_desc(desc);
                 return status;
         }