Commit 718e05ed authored by Lars Poeschel's avatar Lars Poeschel Committed by Miguel Ojeda
Browse files

auxdisplay: Introduce hd44780_common.[ch] 



There is some hd44780 specific code in charlcd and this code is used by
multiple drivers. To make charlcd independent from this device specific
code this has to be moved to a place where the multiple drivers can
share their common code. This common place is now introduced as
hd44780_common.

Reviewed-by: default avatarWilly Tarreau <w@1wt.eu>
Signed-off-by: default avatarLars Poeschel <poeschel@lemonage.de>
Signed-off-by: default avatarMiguel Ojeda <ojeda@kernel.org>
parent 66ce7d5c

drivers/auxdisplay/Kconfig

+20 −0
Original line number Diff line number Diff line
@@ -16,10 +16,29 @@ menuconfig AUXDISPLAY 


if AUXDISPLAY



config CHARLCD

	tristate "Character LCD core support" if COMPILE_TEST

	help

	  This is the base system for character-based LCD displays.

	  It makes no sense to have this alone, you select your display driver

	  and if it needs the charlcd core, it will select it automatically.

	  This is some character LCD core interface that multiple drivers can

	  use.



config HD44780_COMMON

	tristate "Common functions for HD44780 (and compatibles) LCD displays" if COMPILE_TEST

	help

	  This is a module with the common symbols for HD44780 (and compatibles)

	  displays. This is the code that multiple other modules use. It is not

	  useful alone. If you have some sort of HD44780 compatible display,

	  you very likely use this. It is selected automatically by selecting

	  your concrete display.



config HD44780

	tristate "HD44780 Character LCD support"

	depends on GPIOLIB || COMPILE_TEST

	select CHARLCD

	select HD44780_COMMON

	help

	  Enable support for Character LCDs using a HD44780 controller.

	  The LCD is accessible through the /dev/lcd char device (10, 156).
@@ -168,6 +187,7 @@ menuconfig PARPORT_PANEL 
	tristate "Parallel port LCD/Keypad Panel support"

	depends on PARPORT

	select CHARLCD

	select HD44780_COMMON

	help

	  Say Y here if you have an HD44780 or KS-0074 LCD connected to your

	  parallel port. This driver also features 4 and 6-key keypads. The LCD

drivers/auxdisplay/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 
#



obj-$(CONFIG_CHARLCD)		+= charlcd.o

obj-$(CONFIG_HD44780_COMMON)	+= hd44780_common.o

obj-$(CONFIG_ARM_CHARLCD)	+= arm-charlcd.o

obj-$(CONFIG_KS0108)		+= ks0108.o

obj-$(CONFIG_CFAG12864B)	+= cfag12864b.o cfag12864bfb.o

drivers/auxdisplay/hd44780.c

+29 −14
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#include <linux/slab.h>



#include "charlcd.h"

#include "hd44780_common.h"



enum hd44780_pin {

	/* Order does matter due to writing to GPIO array subsets! */
@@ -179,8 +180,9 @@ static int hd44780_probe(struct platform_device *pdev) 
	struct device *dev = &pdev->dev;

	unsigned int i, base;

	struct charlcd *lcd;

	struct hd44780_common *hdc;

	struct hd44780 *hd;

	int ifwidth, ret;

	int ifwidth, ret = -ENOMEM;



	/* Required pins */

	ifwidth = gpiod_count(dev, "data");
@@ -198,31 +200,39 @@ static int hd44780_probe(struct platform_device *pdev) 
		return -EINVAL;

	}



	hdc = hd44780_common_alloc();

	if (!hdc)

		return -ENOMEM;



	lcd = charlcd_alloc(sizeof(struct hd44780));

	if (!lcd)

		return -ENOMEM;

		goto fail1;



	hd = lcd->drvdata;

	hd = kzalloc(sizeof(struct hd44780), GFP_KERNEL);

	if (!hd)

		goto fail2;



	hdc->hd44780 = hd;

	lcd->drvdata = hdc;

	for (i = 0; i < ifwidth; i++) {

		hd->pins[base + i] = devm_gpiod_get_index(dev, "data", i,

							  GPIOD_OUT_LOW);

		if (IS_ERR(hd->pins[base + i])) {

			ret = PTR_ERR(hd->pins[base + i]);

			goto fail;

			goto fail3;

		}

	}



	hd->pins[PIN_CTRL_E] = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);

	if (IS_ERR(hd->pins[PIN_CTRL_E])) {

		ret = PTR_ERR(hd->pins[PIN_CTRL_E]);

		goto fail;

		goto fail3;

	}



	hd->pins[PIN_CTRL_RS] = devm_gpiod_get(dev, "rs", GPIOD_OUT_HIGH);

	if (IS_ERR(hd->pins[PIN_CTRL_RS])) {

		ret = PTR_ERR(hd->pins[PIN_CTRL_RS]);

		goto fail;

		goto fail3;

	}



	/* Optional pins */
@@ -230,24 +240,24 @@ static int hd44780_probe(struct platform_device *pdev) 
							GPIOD_OUT_LOW);

	if (IS_ERR(hd->pins[PIN_CTRL_RW])) {

		ret = PTR_ERR(hd->pins[PIN_CTRL_RW]);

		goto fail;

		goto fail3;

	}



	hd->pins[PIN_CTRL_BL] = devm_gpiod_get_optional(dev, "backlight",

							GPIOD_OUT_LOW);

	if (IS_ERR(hd->pins[PIN_CTRL_BL])) {

		ret = PTR_ERR(hd->pins[PIN_CTRL_BL]);

		goto fail;

		goto fail3;

	}



	/* Required properties */

	ret = device_property_read_u32(dev, "display-height-chars",

				       &lcd->height);

	if (ret)

		goto fail;

		goto fail3;

	ret = device_property_read_u32(dev, "display-width-chars", &lcd->width);

	if (ret)

		goto fail;

		goto fail3;



	/*

	 * On displays with more than two rows, the internal buffer width is
@@ -264,13 +274,17 @@ static int hd44780_probe(struct platform_device *pdev) 


	ret = charlcd_register(lcd);

	if (ret)

		goto fail;

		goto fail3;



	platform_set_drvdata(pdev, lcd);

	return 0;



fail:

	charlcd_free(lcd);

fail3:

	kfree(hd);

fail2:

	kfree(lcd);

fail1:

	kfree(hdc);

	return ret;

}
@@ -278,9 +292,10 @@ static int hd44780_remove(struct platform_device *pdev) 
{

	struct charlcd *lcd = platform_get_drvdata(pdev);



	kfree(lcd->drvdata);

	charlcd_unregister(lcd);



	charlcd_free(lcd);

	kfree(lcd);

	return 0;

}

drivers/auxdisplay/hd44780_common.c

0 → 100644
+19 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-or-later

#include <linux/module.h>

#include <linux/slab.h>



#include "hd44780_common.h"



struct hd44780_common *hd44780_common_alloc(void)

{

	struct hd44780_common *hd;



	hd = kzalloc(sizeof(*hd), GFP_KERNEL);

	if (!hd)

		return NULL;



	return hd;

}

EXPORT_SYMBOL_GPL(hd44780_common_alloc);



MODULE_LICENSE("GPL");

drivers/auxdisplay/hd44780_common.h

0 → 100644
+7 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0-or-later */



struct hd44780_common {

	void *hd44780;

};



struct hd44780_common *hd44780_common_alloc(void);