sh: pfc: Split out gpio chip support.

This implements a bit of rework for the PFC code, making the core itself
slightly more pluggable and moving out the gpio chip handling completely.

The API is preserved in such a way that platforms that depend on it for
early configuration are still able to do so, while making it possible to
migrate to alternate interfaces going forward.

This is the first step of chainsawing necessary to support the pinctrl
API, with the eventual goal being able to decouple pin function state
from the gpio API while retaining gpio chip tie-in for gpio pin functions
only, relying on the pinctrl/pinmux API for non-gpio function demux.

Signed-off-by: Paul Mundt <[email protected]>

drivers/sh/Makefile

@@ -6,5 +6,5 @@ obj-y	:= intc/
 obj-$(CONFIG_HAVE_CLK)		+= clk/
 obj-$(CONFIG_MAPLE)		+= maple/
 obj-$(CONFIG_SUPERHYWAY)	+= superhyway/
-obj-$(CONFIG_GENERIC_GPIO)	+= pfc.o
+obj-$(CONFIG_GENERIC_GPIO)	+= pfc.o pfc-gpio.o
 obj-y				+= pm_runtime.o

drivers/sh/pfc-gpio.c

@@ -0,0 +1,309 @@
+/*
+ * SuperH Pin Function Controller GPIO driver.
+ *
+ * Copyright (C) 2008 Magnus Damm
+ * Copyright (C) 2009 - 2012 Paul Mundt
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/init.h>
+#include <linux/gpio.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+struct sh_pfc_chip {
+	struct sh_pfc		*pfc;
+	struct gpio_chip	gpio_chip;
+};
+
+static struct sh_pfc_chip *gpio_to_pfc_chip(struct gpio_chip *gc)
+{
+	return container_of(gc, struct sh_pfc_chip, gpio_chip);
+}
+
+static struct sh_pfc *gpio_to_pfc(struct gpio_chip *gc)
+{
+	return gpio_to_pfc_chip(gc)->pfc;
+}
+
+static int sh_gpio_request(struct gpio_chip *gc, unsigned offset)
+{
+	struct sh_pfc *pfc = gpio_to_pfc(gc);
+	struct pinmux_data_reg *dummy;
+	unsigned long flags;
+	int i, ret, pinmux_type;
+
+	ret = -EINVAL;
+
+	if (!pfc)
+		goto err_out;
+
+	spin_lock_irqsave(&pfc->lock, flags);
+
+	if ((pfc->gpios[offset].flags & PINMUX_FLAG_TYPE) != PINMUX_TYPE_NONE)
+		goto err_unlock;
+
+	/* setup pin function here if no data is associated with pin */
+
+	if (sh_pfc_get_data_reg(pfc, offset, &dummy, &i) != 0)
+		pinmux_type = PINMUX_TYPE_FUNCTION;
+	else
+		pinmux_type = PINMUX_TYPE_GPIO;
+
+	if (pinmux_type == PINMUX_TYPE_FUNCTION) {
+		if (sh_pfc_config_gpio(pfc, offset,
+				       pinmux_type,
+				       GPIO_CFG_DRYRUN) != 0)
+			goto err_unlock;
+
+		if (sh_pfc_config_gpio(pfc, offset,
+				       pinmux_type,
+				       GPIO_CFG_REQ) != 0)
+			BUG();
+	}
+
+	pfc->gpios[offset].flags &= ~PINMUX_FLAG_TYPE;
+	pfc->gpios[offset].flags |= pinmux_type;
+
+	ret = 0;
+ err_unlock:
+	spin_unlock_irqrestore(&pfc->lock, flags);
+ err_out:
+	return ret;
+}
+
+static void sh_gpio_free(struct gpio_chip *gc, unsigned offset)
+{
+	struct sh_pfc *pfc = gpio_to_pfc(gc);
+	unsigned long flags;
+	int pinmux_type;
+
+	if (!pfc)
+		return;
+
+	spin_lock_irqsave(&pfc->lock, flags);
+
+	pinmux_type = pfc->gpios[offset].flags & PINMUX_FLAG_TYPE;
+	sh_pfc_config_gpio(pfc, offset, pinmux_type, GPIO_CFG_FREE);
+	pfc->gpios[offset].flags &= ~PINMUX_FLAG_TYPE;
+	pfc->gpios[offset].flags |= PINMUX_TYPE_NONE;
+
+	spin_unlock_irqrestore(&pfc->lock, flags);
+}
+
+static int sh_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
+{
+	struct sh_pfc *pfc = gpio_to_pfc(gc);
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&pfc->lock, flags);
+	ret = sh_pfc_set_direction(pfc, offset, PINMUX_TYPE_INPUT);
+	spin_unlock_irqrestore(&pfc->lock, flags);
+
+	return ret;
+}
+
+static void sh_gpio_set_value(struct sh_pfc *pfc, unsigned gpio, int value)
+{
+	struct pinmux_data_reg *dr = NULL;
+	int bit = 0;
+
+	if (!pfc || sh_pfc_get_data_reg(pfc, gpio, &dr, &bit) != 0)
+		BUG();
+	else
+		sh_pfc_write_bit(dr, bit, value);
+}
+
+static int sh_gpio_direction_output(struct gpio_chip *gc, unsigned offset,
+				    int value)
+{
+	struct sh_pfc *pfc = gpio_to_pfc(gc);
+	unsigned long flags;
+	int ret;
+
+	sh_gpio_set_value(pfc, offset, value);
+
+	spin_lock_irqsave(&pfc->lock, flags);
+	ret = sh_pfc_set_direction(pfc, offset, PINMUX_TYPE_OUTPUT);
+	spin_unlock_irqrestore(&pfc->lock, flags);
+
+	return ret;
+}
+
+static int sh_gpio_get_value(struct sh_pfc *pfc, unsigned gpio)
+{
+	struct pinmux_data_reg *dr = NULL;
+	int bit = 0;
+
+	if (!pfc || sh_pfc_get_data_reg(pfc, gpio, &dr, &bit) != 0)
+		return -EINVAL;
+
+	return sh_pfc_read_bit(dr, bit);
+}
+
+static int sh_gpio_get(struct gpio_chip *gc, unsigned offset)
+{
+	return sh_gpio_get_value(gpio_to_pfc(gc), offset);
+}
+
+static void sh_gpio_set(struct gpio_chip *gc, unsigned offset, int value)
+{
+	sh_gpio_set_value(gpio_to_pfc(gc), offset, value);
+}
+
+static int sh_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
+{
+	struct sh_pfc *pfc = gpio_to_pfc(gc);
+	pinmux_enum_t enum_id;
+	pinmux_enum_t *enum_ids;
+	int i, k, pos;
+
+	pos = 0;
+	enum_id = 0;
+	while (1) {
+		pos = sh_pfc_gpio_to_enum(pfc, offset, pos, &enum_id);
+		if (pos <= 0 || !enum_id)
+			break;
+
+		for (i = 0; i < pfc->gpio_irq_size; i++) {
+			enum_ids = pfc->gpio_irq[i].enum_ids;
+			for (k = 0; enum_ids[k]; k++) {
+				if (enum_ids[k] == enum_id)
+					return pfc->gpio_irq[i].irq;
+			}
+		}
+	}
+
+	return -ENOSYS;
+}
+
+static void sh_pfc_gpio_setup(struct sh_pfc_chip *chip)
+{
+	struct sh_pfc *pfc = chip->pfc;
+	struct gpio_chip *gc = &chip->gpio_chip;
+
+	gc->request = sh_gpio_request;
+	gc->free = sh_gpio_free;
+	gc->direction_input = sh_gpio_direction_input;
+	gc->get = sh_gpio_get;
+	gc->direction_output = sh_gpio_direction_output;
+	gc->set = sh_gpio_set;
+	gc->to_irq = sh_gpio_to_irq;
+
+	WARN_ON(pfc->first_gpio != 0); /* needs testing */
+
+	gc->label = pfc->name;
+	gc->owner = THIS_MODULE;
+	gc->base = pfc->first_gpio;
+	gc->ngpio = (pfc->last_gpio - pfc->first_gpio) + 1;
+}
+
+int sh_pfc_register_gpiochip(struct sh_pfc *pfc)
+{
+	struct sh_pfc_chip *chip;
+	int ret;
+
+	chip = kzalloc(sizeof(struct sh_pfc_chip), GFP_KERNEL);
+	if (unlikely(!chip))
+		return -ENOMEM;
+
+	chip->pfc = pfc;
+
+	sh_pfc_gpio_setup(chip);
+
+	ret = gpiochip_add(&chip->gpio_chip);
+	if (unlikely(ret < 0))
+		kfree(chip);
+
+	pr_info("%s handling gpio %d -> %d\n",
+		pfc->name, pfc->first_gpio, pfc->last_gpio);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(sh_pfc_register_gpiochip);
+
+static int sh_pfc_gpio_match(struct gpio_chip *gc, void *data)
+{
+	return !!strstr(gc->label, data);
+}
+
+static int __devinit sh_pfc_gpio_probe(struct platform_device *pdev)
+{
+	struct sh_pfc_chip *chip;
+	struct gpio_chip *gc;
+
+	gc = gpiochip_find("_pfc", sh_pfc_gpio_match);
+	if (unlikely(!gc)) {
+		pr_err("Cant find gpio chip\n");
+		return -ENODEV;
+	}
+
+	chip = gpio_to_pfc_chip(gc);
+	platform_set_drvdata(pdev, chip);
+
+	pr_info("attaching to GPIO chip %s\n", chip->pfc->name);
+
+	return 0;
+}
+
+static int __devexit sh_pfc_gpio_remove(struct platform_device *pdev)
+{
+	struct sh_pfc_chip *chip = platform_get_drvdata(pdev);
+	int ret;
+
+	ret = gpiochip_remove(&chip->gpio_chip);
+	if (unlikely(ret < 0))
+		return ret;
+
+	kfree(chip);
+	return 0;
+}
+
+static struct platform_driver sh_pfc_gpio_driver = {
+	.probe		= sh_pfc_gpio_probe,
+	.remove		= __devexit_p(sh_pfc_gpio_remove),
+	.driver		= {
+		.name	= KBUILD_MODNAME,
+		.owner	= THIS_MODULE,
+	},
+};
+
+static struct platform_device sh_pfc_gpio_device = {
+	.name		= KBUILD_MODNAME,
+	.id		= -1,
+};
+
+static int __init sh_pfc_gpio_init(void)
+{
+	int rc;
+
+	rc = platform_driver_register(&sh_pfc_gpio_driver);
+	if (likely(!rc)) {
+		rc = platform_device_register(&sh_pfc_gpio_device);
+		if (unlikely(rc))
+			platform_driver_unregister(&sh_pfc_gpio_driver);
+	}
+
+	return rc;
+}
+
+static void __exit sh_pfc_gpio_exit(void)
+{
+	platform_device_unregister(&sh_pfc_gpio_device);
+	platform_driver_unregister(&sh_pfc_gpio_driver);
+}
+
+module_init(sh_pfc_gpio_init);
+module_exit(sh_pfc_gpio_exit);
+
+MODULE_AUTHOR("Magnus Damm, Paul Mundt");
+MODULE_DESCRIPTION("GPIO driver for SuperH pin function controller");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:pfc-gpio");