drivers/video/fbdev/via/via-gpio.c - third_party/kernel - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Support for viafb GPIO ports.
  *
  * Copyright 2009 Jonathan Corbet <corbet@lwn.net>
  */

 #include <linux/spinlock.h>
 #include <linux/gpio/driver.h>
 #include <linux/platform_device.h>
 #include <linux/via-core.h>
 #include <linux/via-gpio.h>
 #include <linux/export.h>

 /*
  * The ports we know about.  Note that the port-25 gpios are not
  * mentioned in the datasheet.
  */

 struct viafb_gpio {
 	char *vg_name;	/* Data sheet name */
 	u16 vg_io_port;
 	u8  vg_port_index;
 	int  vg_mask_shift;
 };

 static struct viafb_gpio viafb_all_gpios[] = {
 	{
 		.vg_name = "VGPIO0",  /* Guess - not in datasheet */
 		.vg_io_port = VIASR,
 		.vg_port_index = 0x25,
 		.vg_mask_shift = 1
 	},
 	{
 		.vg_name = "VGPIO1",
 		.vg_io_port = VIASR,
 		.vg_port_index = 0x25,
 		.vg_mask_shift = 0
 	},
 	{
 		.vg_name = "VGPIO2",  /* aka DISPCLKI0 */
 		.vg_io_port = VIASR,
 		.vg_port_index = 0x2c,
 		.vg_mask_shift = 1
 	},
 	{
 		.vg_name = "VGPIO3",  /* aka DISPCLKO0 */
 		.vg_io_port = VIASR,
 		.vg_port_index = 0x2c,
 		.vg_mask_shift = 0
 	},
 	{
 		.vg_name = "VGPIO4",  /* DISPCLKI1 */
 		.vg_io_port = VIASR,
 		.vg_port_index = 0x3d,
 		.vg_mask_shift = 1
 	},
 	{
 		.vg_name = "VGPIO5",  /* DISPCLKO1 */
 		.vg_io_port = VIASR,
 		.vg_port_index = 0x3d,
 		.vg_mask_shift = 0
 	},
 };

 #define VIAFB_NUM_GPIOS ARRAY_SIZE(viafb_all_gpios)

 /*
  * This structure controls the active GPIOs, which may be a subset
  * of those which are known.
  */

 struct viafb_gpio_cfg {
 	struct gpio_chip gpio_chip;
 	struct viafb_dev *vdev;
 	struct viafb_gpio *active_gpios[VIAFB_NUM_GPIOS];
 	const char *gpio_names[VIAFB_NUM_GPIOS];
 };

 /*
  * GPIO access functions
  */
 static void via_gpio_set(struct gpio_chip *chip, unsigned int nr,
 			 int value)
 {
 	struct viafb_gpio_cfg *cfg = gpiochip_get_data(chip);
 	u8 reg;
 	struct viafb_gpio *gpio;
 	unsigned long flags;

 	spin_lock_irqsave(&cfg->vdev->reg_lock, flags);
 	gpio = cfg->active_gpios[nr];
 	reg = via_read_reg(VIASR, gpio->vg_port_index);
 	reg |= 0x40 << gpio->vg_mask_shift;  /* output enable */
 	if (value)
 		reg |= 0x10 << gpio->vg_mask_shift;
 	else
 		reg &= ~(0x10 << gpio->vg_mask_shift);
 	via_write_reg(VIASR, gpio->vg_port_index, reg);
 	spin_unlock_irqrestore(&cfg->vdev->reg_lock, flags);
 }

 static int via_gpio_dir_out(struct gpio_chip *chip, unsigned int nr,
 			    int value)
 {
 	via_gpio_set(chip, nr, value);
 	return 0;
 }

 /*
  * Set the input direction.  I'm not sure this is right; we should
  * be able to do input without disabling output.
  */
 static int via_gpio_dir_input(struct gpio_chip *chip, unsigned int nr)
 {
 	struct viafb_gpio_cfg *cfg = gpiochip_get_data(chip);
 	struct viafb_gpio *gpio;
 	unsigned long flags;

 	spin_lock_irqsave(&cfg->vdev->reg_lock, flags);
 	gpio = cfg->active_gpios[nr];
 	via_write_reg_mask(VIASR, gpio->vg_port_index, 0,
 			0x40 << gpio->vg_mask_shift);
 	spin_unlock_irqrestore(&cfg->vdev->reg_lock, flags);
 	return 0;
 }

 static int via_gpio_get(struct gpio_chip *chip, unsigned int nr)
 {
 	struct viafb_gpio_cfg *cfg = gpiochip_get_data(chip);
 	u8 reg;
 	struct viafb_gpio *gpio;
 	unsigned long flags;

 	spin_lock_irqsave(&cfg->vdev->reg_lock, flags);
 	gpio = cfg->active_gpios[nr];
 	reg = via_read_reg(VIASR, gpio->vg_port_index);
 	spin_unlock_irqrestore(&cfg->vdev->reg_lock, flags);
 	return !!(reg & (0x04 << gpio->vg_mask_shift));
 }


 static struct viafb_gpio_cfg viafb_gpio_config = {
 	.gpio_chip = {
 		.label = "VIAFB onboard GPIO",
 		.owner = THIS_MODULE,
 		.direction_output = via_gpio_dir_out,
 		.set = via_gpio_set,
 		.direction_input = via_gpio_dir_input,
 		.get = via_gpio_get,
 		.base = -1,
 		.ngpio = 0,
 		.can_sleep = 0
 	}
 };

 /*
  * Manage the software enable bit.
  */
 static void viafb_gpio_enable(struct viafb_gpio *gpio)
 {
 	via_write_reg_mask(VIASR, gpio->vg_port_index, 0x02, 0x02);
 }

 static void viafb_gpio_disable(struct viafb_gpio *gpio)
 {
 	via_write_reg_mask(VIASR, gpio->vg_port_index, 0, 0x02);
 }

 #ifdef CONFIG_PM

 static int viafb_gpio_suspend(void *private)
 {
 	return 0;
 }

 static int viafb_gpio_resume(void *private)
 {
 	int i;

 	for (i = 0; i < viafb_gpio_config.gpio_chip.ngpio; i += 2)
 		viafb_gpio_enable(viafb_gpio_config.active_gpios[i]);
 	return 0;
 }

 static struct viafb_pm_hooks viafb_gpio_pm_hooks = {
 	.suspend = viafb_gpio_suspend,
 	.resume = viafb_gpio_resume
 };
 #endif /* CONFIG_PM */

 /*
  * Look up a specific gpio and return the number it was assigned.
  */
 int viafb_gpio_lookup(const char *name)
 {
 	int i;

 	for (i = 0; i < viafb_gpio_config.gpio_chip.ngpio; i++)
 		if (!strcmp(name, viafb_gpio_config.active_gpios[i]->vg_name))
 			return viafb_gpio_config.gpio_chip.base + i;
 	return -1;
 }
 EXPORT_SYMBOL_GPL(viafb_gpio_lookup);

 /*
  * Platform device stuff.
  */
 static int viafb_gpio_probe(struct platform_device *platdev)
 {
 	struct viafb_dev *vdev = platdev->dev.platform_data;
 	struct via_port_cfg *port_cfg = vdev->port_cfg;
 	int i, ngpio = 0, ret;
 	struct viafb_gpio *gpio;
 	unsigned long flags;

 	/*
 	 * Set up entries for all GPIOs which have been configured to
 	 * operate as such (as opposed to as i2c ports).
 	 */
 	for (i = 0; i < VIAFB_NUM_PORTS; i++) {
 		if (port_cfg[i].mode != VIA_MODE_GPIO)
 			continue;
 		for (gpio = viafb_all_gpios;
 		     gpio < viafb_all_gpios + VIAFB_NUM_GPIOS; gpio++)
 			if (gpio->vg_port_index == port_cfg[i].ioport_index) {
 				viafb_gpio_config.active_gpios[ngpio] = gpio;
 				viafb_gpio_config.gpio_names[ngpio] =
 					gpio->vg_name;
 				ngpio++;
 			}
 	}
 	viafb_gpio_config.gpio_chip.ngpio = ngpio;
 	viafb_gpio_config.gpio_chip.names = viafb_gpio_config.gpio_names;
 	viafb_gpio_config.vdev = vdev;
 	if (ngpio == 0) {
 		printk(KERN_INFO "viafb: no GPIOs configured\n");
 		return 0;
 	}
 	/*
 	 * Enable the ports.  They come in pairs, with a single
 	 * enable bit for both.
 	 */
 	spin_lock_irqsave(&viafb_gpio_config.vdev->reg_lock, flags);
 	for (i = 0; i < ngpio; i += 2)
 		viafb_gpio_enable(viafb_gpio_config.active_gpios[i]);
 	spin_unlock_irqrestore(&viafb_gpio_config.vdev->reg_lock, flags);
 	/*
 	 * Get registered.
 	 */
 	viafb_gpio_config.gpio_chip.base = -1;  /* Dynamic */
 	ret = gpiochip_add_data(&viafb_gpio_config.gpio_chip,
 				&viafb_gpio_config);
 	if (ret) {
 		printk(KERN_ERR "viafb: failed to add gpios (%d)\n", ret);
 		viafb_gpio_config.gpio_chip.ngpio = 0;
 	}
 #ifdef CONFIG_PM
 	viafb_pm_register(&viafb_gpio_pm_hooks);
 #endif
 	return ret;
 }


 static int viafb_gpio_remove(struct platform_device *platdev)
 {
 	unsigned long flags;
 	int i;

 #ifdef CONFIG_PM
 	viafb_pm_unregister(&viafb_gpio_pm_hooks);
 #endif

 	/*
 	 * Get unregistered.
 	 */
 	if (viafb_gpio_config.gpio_chip.ngpio > 0) {
 		gpiochip_remove(&viafb_gpio_config.gpio_chip);
 	}
 	/*
 	 * Disable the ports.
 	 */
 	spin_lock_irqsave(&viafb_gpio_config.vdev->reg_lock, flags);
 	for (i = 0; i < viafb_gpio_config.gpio_chip.ngpio; i += 2)
 		viafb_gpio_disable(viafb_gpio_config.active_gpios[i]);
 	viafb_gpio_config.gpio_chip.ngpio = 0;
 	spin_unlock_irqrestore(&viafb_gpio_config.vdev->reg_lock, flags);
 	return 0;
 }

 static struct platform_driver via_gpio_driver = {
 	.driver = {
 		.name = "viafb-gpio",
 	},
 	.probe = viafb_gpio_probe,
 	.remove = viafb_gpio_remove,
 };

 int viafb_gpio_init(void)
 {
 	return platform_driver_register(&via_gpio_driver);
 }

 void viafb_gpio_exit(void)
 {
 	platform_driver_unregister(&via_gpio_driver);
 }
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Support for viafb GPIO ports.
	*
	* Copyright 2009 Jonathan Corbet <corbet@lwn.net>
	*/

	#include <linux/spinlock.h>
	#include <linux/gpio/driver.h>
	#include <linux/platform_device.h>
	#include <linux/via-core.h>
	#include <linux/via-gpio.h>
	#include <linux/export.h>

	/*
	* The ports we know about. Note that the port-25 gpios are not
	* mentioned in the datasheet.
	*/

	struct viafb_gpio {
	char vg_name; / Data sheet name */
	u16 vg_io_port;
	u8 vg_port_index;
	int vg_mask_shift;
	};

	static struct viafb_gpio viafb_all_gpios[] = {
	{
	.vg_name = "VGPIO0", /* Guess - not in datasheet */
	.vg_io_port = VIASR,
	.vg_port_index = 0x25,
	.vg_mask_shift = 1
	},
	{
	.vg_name = "VGPIO1",
	.vg_io_port = VIASR,
	.vg_port_index = 0x25,
	.vg_mask_shift = 0
	},
	{
	.vg_name = "VGPIO2", /* aka DISPCLKI0 */
	.vg_io_port = VIASR,
	.vg_port_index = 0x2c,
	.vg_mask_shift = 1
	},
	{
	.vg_name = "VGPIO3", /* aka DISPCLKO0 */
	.vg_io_port = VIASR,
	.vg_port_index = 0x2c,
	.vg_mask_shift = 0
	},
	{
	.vg_name = "VGPIO4", /* DISPCLKI1 */
	.vg_io_port = VIASR,
	.vg_port_index = 0x3d,
	.vg_mask_shift = 1
	},
	{
	.vg_name = "VGPIO5", /* DISPCLKO1 */
	.vg_io_port = VIASR,
	.vg_port_index = 0x3d,
	.vg_mask_shift = 0
	},
	};

	#define VIAFB_NUM_GPIOS ARRAY_SIZE(viafb_all_gpios)

	/*
	* This structure controls the active GPIOs, which may be a subset
	* of those which are known.
	*/

	struct viafb_gpio_cfg {
	struct gpio_chip gpio_chip;
	struct viafb_dev *vdev;
	struct viafb_gpio *active_gpios[VIAFB_NUM_GPIOS];
	const char *gpio_names[VIAFB_NUM_GPIOS];
	};

	/*
	* GPIO access functions
	*/
	static void via_gpio_set(struct gpio_chip *chip, unsigned int nr,
	int value)
	{
	struct viafb_gpio_cfg *cfg = gpiochip_get_data(chip);
	u8 reg;
	struct viafb_gpio *gpio;
	unsigned long flags;

	spin_lock_irqsave(&cfg->vdev->reg_lock, flags);
	gpio = cfg->active_gpios[nr];
	reg = via_read_reg(VIASR, gpio->vg_port_index);
	reg \|= 0x40 << gpio->vg_mask_shift; /* output enable */
	if (value)
	reg \|= 0x10 << gpio->vg_mask_shift;
	else
	reg &= ~(0x10 << gpio->vg_mask_shift);
	via_write_reg(VIASR, gpio->vg_port_index, reg);
	spin_unlock_irqrestore(&cfg->vdev->reg_lock, flags);
	}

	static int via_gpio_dir_out(struct gpio_chip *chip, unsigned int nr,
	int value)
	{
	via_gpio_set(chip, nr, value);
	return 0;
	}

	/*
	* Set the input direction. I'm not sure this is right; we should
	* be able to do input without disabling output.
	*/
	static int via_gpio_dir_input(struct gpio_chip *chip, unsigned int nr)
	{
	struct viafb_gpio_cfg *cfg = gpiochip_get_data(chip);
	struct viafb_gpio *gpio;
	unsigned long flags;

	spin_lock_irqsave(&cfg->vdev->reg_lock, flags);
	gpio = cfg->active_gpios[nr];
	via_write_reg_mask(VIASR, gpio->vg_port_index, 0,
	0x40 << gpio->vg_mask_shift);
	spin_unlock_irqrestore(&cfg->vdev->reg_lock, flags);
	return 0;
	}

	static int via_gpio_get(struct gpio_chip *chip, unsigned int nr)
	{
	struct viafb_gpio_cfg *cfg = gpiochip_get_data(chip);
	u8 reg;
	struct viafb_gpio *gpio;
	unsigned long flags;

	spin_lock_irqsave(&cfg->vdev->reg_lock, flags);
	gpio = cfg->active_gpios[nr];
	reg = via_read_reg(VIASR, gpio->vg_port_index);
	spin_unlock_irqrestore(&cfg->vdev->reg_lock, flags);
	return !!(reg & (0x04 << gpio->vg_mask_shift));
	}


	static struct viafb_gpio_cfg viafb_gpio_config = {
	.gpio_chip = {
	.label = "VIAFB onboard GPIO",
	.owner = THIS_MODULE,
	.direction_output = via_gpio_dir_out,
	.set = via_gpio_set,
	.direction_input = via_gpio_dir_input,
	.get = via_gpio_get,
	.base = -1,
	.ngpio = 0,
	.can_sleep = 0
	}
	};

	/*
	* Manage the software enable bit.
	*/
	static void viafb_gpio_enable(struct viafb_gpio *gpio)
	{
	via_write_reg_mask(VIASR, gpio->vg_port_index, 0x02, 0x02);
	}

	static void viafb_gpio_disable(struct viafb_gpio *gpio)
	{
	via_write_reg_mask(VIASR, gpio->vg_port_index, 0, 0x02);
	}

	#ifdef CONFIG_PM

	static int viafb_gpio_suspend(void *private)
	{
	return 0;
	}

	static int viafb_gpio_resume(void *private)
	{
	int i;

	for (i = 0; i < viafb_gpio_config.gpio_chip.ngpio; i += 2)
	viafb_gpio_enable(viafb_gpio_config.active_gpios[i]);
	return 0;
	}

	static struct viafb_pm_hooks viafb_gpio_pm_hooks = {
	.suspend = viafb_gpio_suspend,
	.resume = viafb_gpio_resume
	};
	#endif /* CONFIG_PM */

	/*
	* Look up a specific gpio and return the number it was assigned.
	*/
	int viafb_gpio_lookup(const char *name)
	{
	int i;

	for (i = 0; i < viafb_gpio_config.gpio_chip.ngpio; i++)
	if (!strcmp(name, viafb_gpio_config.active_gpios[i]->vg_name))
	return viafb_gpio_config.gpio_chip.base + i;
	return -1;
	}
	EXPORT_SYMBOL_GPL(viafb_gpio_lookup);

	/*
	* Platform device stuff.
	*/
	static int viafb_gpio_probe(struct platform_device *platdev)
	{
	struct viafb_dev *vdev = platdev->dev.platform_data;
	struct via_port_cfg *port_cfg = vdev->port_cfg;
	int i, ngpio = 0, ret;
	struct viafb_gpio *gpio;
	unsigned long flags;

	/*
	* Set up entries for all GPIOs which have been configured to
	* operate as such (as opposed to as i2c ports).
	*/
	for (i = 0; i < VIAFB_NUM_PORTS; i++) {
	if (port_cfg[i].mode != VIA_MODE_GPIO)
	continue;
	for (gpio = viafb_all_gpios;
	gpio < viafb_all_gpios + VIAFB_NUM_GPIOS; gpio++)
	if (gpio->vg_port_index == port_cfg[i].ioport_index) {
	viafb_gpio_config.active_gpios[ngpio] = gpio;
	viafb_gpio_config.gpio_names[ngpio] =
	gpio->vg_name;
	ngpio++;
	}
	}
	viafb_gpio_config.gpio_chip.ngpio = ngpio;
	viafb_gpio_config.gpio_chip.names = viafb_gpio_config.gpio_names;
	viafb_gpio_config.vdev = vdev;
	if (ngpio == 0) {
	printk(KERN_INFO "viafb: no GPIOs configured\n");
	return 0;
	}
	/*
	* Enable the ports. They come in pairs, with a single
	* enable bit for both.
	*/
	spin_lock_irqsave(&viafb_gpio_config.vdev->reg_lock, flags);
	for (i = 0; i < ngpio; i += 2)
	viafb_gpio_enable(viafb_gpio_config.active_gpios[i]);
	spin_unlock_irqrestore(&viafb_gpio_config.vdev->reg_lock, flags);
	/*
	* Get registered.
	*/
	viafb_gpio_config.gpio_chip.base = -1; /* Dynamic */
	ret = gpiochip_add_data(&viafb_gpio_config.gpio_chip,
	&viafb_gpio_config);
	if (ret) {
	printk(KERN_ERR "viafb: failed to add gpios (%d)\n", ret);
	viafb_gpio_config.gpio_chip.ngpio = 0;
	}
	#ifdef CONFIG_PM
	viafb_pm_register(&viafb_gpio_pm_hooks);
	#endif
	return ret;
	}


	static int viafb_gpio_remove(struct platform_device *platdev)
	{
	unsigned long flags;
	int i;

	#ifdef CONFIG_PM
	viafb_pm_unregister(&viafb_gpio_pm_hooks);
	#endif

	/*
	* Get unregistered.
	*/
	if (viafb_gpio_config.gpio_chip.ngpio > 0) {
	gpiochip_remove(&viafb_gpio_config.gpio_chip);
	}
	/*
	* Disable the ports.
	*/
	spin_lock_irqsave(&viafb_gpio_config.vdev->reg_lock, flags);
	for (i = 0; i < viafb_gpio_config.gpio_chip.ngpio; i += 2)
	viafb_gpio_disable(viafb_gpio_config.active_gpios[i]);
	viafb_gpio_config.gpio_chip.ngpio = 0;
	spin_unlock_irqrestore(&viafb_gpio_config.vdev->reg_lock, flags);
	return 0;
	}

	static struct platform_driver via_gpio_driver = {
	.driver = {
	.name = "viafb-gpio",
	},
	.probe = viafb_gpio_probe,
	.remove = viafb_gpio_remove,
	};

	int viafb_gpio_init(void)
	{
	return platform_driver_register(&via_gpio_driver);
	}

	void viafb_gpio_exit(void)
	{
	platform_driver_unregister(&via_gpio_driver);
	}