Merge tag 'gpio-v4.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

Pull GPIO updates from Linus Walleij:
 "Here is the bulk of GPIO changes for v4.5.

  Notably there are big refactorings mostly by myself, aimed at getting
  the gpio_chip into a shape that makes me believe I can proceed to
  preserve state for a proper userspace ABI (character device) that has
  already been proposed once, but resulted in the feedback that I need
  to go back and restructure stuff.  So I've been restructuring stuff.
  On the way I ran into brokenness (return code from the get_value()
  callback) and had to fix it.  Also, refactored generic GPIO to be
  simpler.

  Some of that is still waiting to trickle down from the subsystems all
  over the kernel that provide random gpio_chips, I've touched every
  single GPIO driver in the kernel now, oh man I didn't know I was
  responsible for so much...

  Apart from that we're churning along as usual.

  I took some effort to test and retest so it should merge nicely and we
  shook out a couple of bugs in -next.

  Infrastructural changes:

   - In struct gpio_chip, rename the .dev node to .parent to better
     reflect the fact that this is not the GPIO struct device
     abstraction.  We will add that soon so this would be totallt
     confusing.

   - It was noted that the driver .get_value() callbacks was sometimes
     reporting negative -ERR values to the gpiolib core, expecting them
     to be propagated to consumer gpiod_get_value() and gpio_get_value()
     calls.  This was not happening, so as there was a mess of drivers
     returning negative errors and some returning "anything else than
     zero" to indicate that a line was active.  As some would have bit
     31 set to indicate "line active" it clashed with negative error
     codes.  This is fixed by the largeish series clamping values in all
     drivers with !!value to [0,1] and then augmenting the code to
     propagate error codes to consumers.  (Includes some ACKed patches
     in other subsystems.)

   - Add a void *data pointer to struct gpio_chip.  The container_of()
     design pattern is indeed very nice, but we want to reform the
     struct gpio_chip to be a non-volative, stateless business, and keep
     states internal to the gpiolib to be able to hold on to the state
     when adding a proper userspace ABI (character device) further down
     the road.  To achieve this, drivers need a handle at the internal
     state that is not dependent on their struct gpio_chip() so we add
     gpiochip_add_data() and gpiochip_get_data() following the pattern
     of many other subsystems.  All the "use gpiochip data pointer"
     patches transforms drivers to this scheme.

   - The Generic GPIO chip header has been merged into the general
     <linux/gpio/driver.h> header, and the custom header for that
     removed.  Instead of having a separate mm_gpio_chip struct for
     these generic drivers, merge that into struct gpio_chip,
     simplifying the code and removing the need for separate and
     confusing includes.

  Misc improvements:

   - Stabilize the way GPIOs are looked up from the ACPI legacy
     specification.

   - Incremental driver features for PXA, PCA953X, Lantiq (patches from
     the OpenWRT community), RCAR, Zynq, PL061, 104-idi-48

  New drivers:

   - Add a GPIO chip to the ALSA SoC AC97 driver.

   - Add a new Broadcom NSP SoC driver (this lands in the pinctrl dir,
     but the branch is merged here too to account for infrastructural
     changes).

   - The sx150x driver now supports the sx1502"

* tag 'gpio-v4.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (220 commits)
  gpio: generic: make bgpio_pdata always visible
  gpiolib: fix chip order in gpio list
  gpio: mpc8xxx: Do not use gpiochip_get_data() in mpc8xxx_gpio_save_regs()
  gpio: mm-lantiq: Do not use gpiochip_get_data() in ltq_mm_save_regs()
  gpio: brcmstb: Allow building driver for BMIPS_GENERIC
  gpio: brcmstb: Set endian flags for big-endian MIPS
  gpio: moxart: fix build regression
  gpio: xilinx: Do not use gpiochip_get_data() in xgpio_save_regs()
  leds: pca9532: use gpiochip data pointer
  leds: tca6507: use gpiochip data pointer
  hid: cp2112: use gpiochip data pointer
  bcma: gpio: use gpiochip data pointer
  avr32: gpio: use gpiochip data pointer
  video: fbdev: via: use gpiochip data pointer
  gpio: pch: Optimize pch_gpio_get()
  Revert "pinctrl: lantiq: Implement gpio_chip.to_irq"
  pinctrl: nsp-gpio: use gpiochip data pointer
  pinctrl: vt8500-wmt: use gpiochip data pointer
  pinctrl: exynos5440: use gpiochip data pointer
  pinctrl: at91-pio4: use gpiochip data pointer
  ...

1 files changed, 28 insertions, 51 deletions

diff --git a/drivers/gpio/gpio-74x164.c b/drivers/gpio/gpio-74x164.c
index 60172f835d15..c81224ff2dca 100644
--- a/drivers/gpio/gpio-74x164.c
+++ b/drivers/gpio/gpio-74x164.c
@@ -20,56 +20,34 @@
 #define GEN_74X164_NUMBER_GPIOS	8
 
 struct gen_74x164_chip {
-	u8			*buffer;
 	struct gpio_chip	gpio_chip;
 	struct mutex		lock;
 	u32			registers;
-};
-
-static struct gen_74x164_chip *gpio_to_74x164_chip(struct gpio_chip *gc)
-{
-	return container_of(gc, struct gen_74x164_chip, gpio_chip);
-}
-
-static int __gen_74x164_write_config(struct gen_74x164_chip *chip)
-{
-	struct spi_device *spi = to_spi_device(chip->gpio_chip.dev);
-	struct spi_message message;
-	struct spi_transfer *msg_buf;
-	int i, ret = 0;
-
-	msg_buf = kzalloc(chip->registers * sizeof(struct spi_transfer),
-			GFP_KERNEL);
-	if (!msg_buf)
-		return -ENOMEM;
-
-	spi_message_init(&message);
-
 	/*
 	 * Since the registers are chained, every byte sent will make
 	 * the previous byte shift to the next register in the
-	 * chain. Thus, the first byte send will end up in the last
+	 * chain. Thus, the first byte sent will end up in the last
 	 * register at the end of the transfer. So, to have a logical
-	 * numbering, send the bytes in reverse order so that the last
-	 * byte of the buffer will end up in the last register.
+	 * numbering, store the bytes in reverse order.
 	 */
-	for (i = chip->registers - 1; i >= 0; i--) {
-		msg_buf[i].tx_buf = chip->buffer + i;
-		msg_buf[i].len = sizeof(u8);
-		spi_message_add_tail(msg_buf + i, &message);
-	}
-
-	ret = spi_sync(spi, &message);
+	u8			buffer[0];
+};
 
-	kfree(msg_buf);
+static int __gen_74x164_write_config(struct gen_74x164_chip *chip)
+{
+	struct spi_transfer xfer = {
+		.tx_buf = chip->buffer,
+		.len = chip->registers,
+	};
 
-	return ret;
+	return spi_sync_transfer(to_spi_device(chip->gpio_chip.parent),
+				 &xfer, 1);
 }
 
 static int gen_74x164_get_value(struct gpio_chip *gc, unsigned offset)
 {
-	struct gen_74x164_chip *chip = gpio_to_74x164_chip(gc);
-	u8 bank = offset / 8;
+	struct gen_74x164_chip *chip = gpiochip_get_data(gc);
+	u8 bank = chip->registers - 1 - offset / 8;
 	u8 pin = offset % 8;
 	int ret;
 
@@ -83,8 +61,8 @@ static int gen_74x164_get_value(struct gpio_chip *gc, unsigned offset)
 static void gen_74x164_set_value(struct gpio_chip *gc,
 		unsigned offset, int val)
 {
-	struct gen_74x164_chip *chip = gpio_to_74x164_chip(gc);
-	u8 bank = offset / 8;
+	struct gen_74x164_chip *chip = gpiochip_get_data(gc);
+	u8 bank = chip->registers - 1 - offset / 8;
 	u8 pin = offset % 8;
 
 	mutex_lock(&chip->lock);
@@ -107,6 +85,7 @@ static int gen_74x164_direction_output(struct gpio_chip *gc,
 static int gen_74x164_probe(struct spi_device *spi)
 {
 	struct gen_74x164_chip *chip;
+	u32 nregs;
 	int ret;
 
 	/*
@@ -118,7 +97,14 @@ static int gen_74x164_probe(struct spi_device *spi)
 	if (ret < 0)
 		return ret;
 
-	chip = devm_kzalloc(&spi->dev, sizeof(*chip), GFP_KERNEL);
+	if (of_property_read_u32(spi->dev.of_node, "registers-number",
+				 &nregs)) {
+		dev_err(&spi->dev,
+			"Missing registers-number property in the DT.\n");
+		return -EINVAL;
+	}
+
+	chip = devm_kzalloc(&spi->dev, sizeof(*chip) + nregs, GFP_KERNEL);
 	if (!chip)
 		return -ENOMEM;
 
@@ -130,20 +116,11 @@ static int gen_74x164_probe(struct spi_device *spi)
 	chip->gpio_chip.set = gen_74x164_set_value;
 	chip->gpio_chip.base = -1;
 
-	if (of_property_read_u32(spi->dev.of_node, "registers-number",
-				 &chip->registers)) {
-		dev_err(&spi->dev,
-			"Missing registers-number property in the DT.\n");
-		return -EINVAL;
-	}
-
+	chip->registers = nregs;
 	chip->gpio_chip.ngpio = GEN_74X164_NUMBER_GPIOS * chip->registers;
-	chip->buffer = devm_kzalloc(&spi->dev, chip->registers, GFP_KERNEL);
-	if (!chip->buffer)
-		return -ENOMEM;
 
 	chip->gpio_chip.can_sleep = true;
-	chip->gpio_chip.dev = &spi->dev;
+	chip->gpio_chip.parent = &spi->dev;
 	chip->gpio_chip.owner = THIS_MODULE;
 
 	mutex_init(&chip->lock);
@@ -154,7 +131,7 @@ static int gen_74x164_probe(struct spi_device *spi)
 		goto exit_destroy;
 	}
 
-	ret = gpiochip_add(&chip->gpio_chip);
+	ret = gpiochip_add_data(&chip->gpio_chip, chip);
 	if (!ret)
 		return 0;