[PATCH 00/25] Make charlcd device independent

[PATCH 00/25] Make charlcd device independent

[poeschel]

From: Lars Poeschel <poeschel@lemonage.de>

This tries to make charlcd device independent. At the moment hd44780
device specific code is contained deep in charlcd. This moves this out
into a hd44780_common module, where the two hd44780 drivers we have at
the moment (hd44780 and panel) can use this from. The goal is that at
the end other drivers can use the charlcd interface.
I add one such driver for a modtronix lcd displau  with the last patch.
I submitted this already some time ago, where the wish was so split
this into smaller chunks what I try to do with this patchset.

This is v5 of the patchset. I address a few review comments with this.
I fixed some typos, but more importantly Miguel spotted that I reverted
commit 3f03b6498 ("auxdisplay: charlcd: Reuse hex_to_bin() instead of
custom code") during rebasing. This is corrected now.

As a note to patch 23:
This might slightly change behaviour.
On hd44780 displays with one or two lines the previous implementation
did still write characters to the buffer of the display even if they are
currently not visible. The shift_display command could be used so set
the "viewing window" to a new position in the buffer and then you could
see the characters previously written.
This described behaviour does not work for hd44780 displays with more
than two display lines. There simply is not enough buffer.
So the behaviour was a bit inconsistens across different displays.
The new behaviour is to stop writing character at the end of a visible
line, even if there would be room in the buffer. This allows us to have
an easy implementation, that should behave equal on all supported
displays. This is not hd44780 hardware dependent anymore.

Link: https://lore.kernel.org/lkml/20191016082430.5955-1-poeschel@lemonage.de/
Link: https://lore.kernel.org/lkml/CANiq72kS-u_Xd_m+2CQVh-JCncPf1XNXrXAZ=4z+mze8fwv2kw@mail.gmail.com/

Changes in v5:
- patch 1: Fix a commit message typo: of -> on
- patch 2: Remove some unnecessary newlines
- patch 8: Fix some typos
- patch 14: Fix commit message typo: it's -> its
- patch 15: this patch is squashed together from the former individual
  hd44780_common_ function patches
- patch 16: combined two cleanup patches
- patch 17: I did previously undo commit 3f03b6498 which was a mistake.
  This is now corrected.
- patch 24: Picked up Robs Reviewed-by
- patch 25: use hex_to_bin like in commit 3f03b6498 but for the lcd2s.c
  file

Changes in v4:
- modtronix -> Modtronix in new lcd2s driver
- Kconfig: remove "default n" in new lcd2s driver

Changes in v3:
- Fix some typos in Kconfig stuff
- Fix kernel test robot reported error: Missed EXPORT_SYMBOL_GPL
- new patch to reduce display timeout
- better patch description to why not move cursor beyond end of a line
- Fixed make dt_binding_doc errors

Changes in v2:
- split whole patch into many smaller chunks
- device tree doc in yaml

Lars Poeschel (25):
  auxdisplay: Use an enum for charlcd  backlight on/off ops
  auxdisplay: Introduce hd44780_common.[ch]
  auxdisplay: Move hwidth and bwidth to struct hd44780_common
  auxdisplay: Move ifwidth to struct hd44780_common
  auxdisplay: Move write_data pointer to hd44780_common
  auxdisplay: Move write_cmd pointers to hd44780 drivers
  auxdisplay: Move addr out of charlcd_priv
  auxdisplay: hd44780_common_print
  auxdisplay: provide hd44780_common_gotoxy
  auxdisplay: add home to charlcd_ops
  auxdisplay: Move clear_display to hd44780_common
  auxdisplay: make charlcd_backlight visible to hd44780_common
  auxdisplay: Make use of enum for backlight on / off
  auxdisplay: Move init_display to hd44780_common
  auxdisplay: implement various hd44780_common_ functions
  auxdisplay: cleanup unnecessary hd44780 code in charlcd
  auxdisplay: Move char redefine code to hd44780_common
  auxdisplay: Call charlcd_backlight in place
  auxdisplay: hd44780_common: Reduce clear_display timeout
  auxdisplay: hd44780: Remove clear_fast
  auxdisplay: charlcd: replace last device specific stuff
  auxdisplay: Change gotoxy calling interface
  auxdisplay: charlcd: Do not print chars at end of line
  auxdisplay: lcd2s DT binding doc
  auxdisplay: add a driver for lcd2s character display

 .../bindings/auxdisplay/modtronix,lcd2s.yaml  |  58 +++
 .../devicetree/bindings/vendor-prefixes.yaml  |   2 +
 drivers/auxdisplay/Kconfig                    |  30 ++
 drivers/auxdisplay/Makefile                   |   2 +
 drivers/auxdisplay/charlcd.c                  | 412 +++++-------------
 drivers/auxdisplay/charlcd.h                  |  86 +++-
 drivers/auxdisplay/hd44780.c                  | 120 +++--
 drivers/auxdisplay/hd44780_common.c           | 361 +++++++++++++++
 drivers/auxdisplay/hd44780_common.h           |  33 ++
 drivers/auxdisplay/lcd2s.c                    | 403 +++++++++++++++++
 drivers/auxdisplay/panel.c                    | 180 ++++----
 11 files changed, 1237 insertions(+), 450 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/auxdisplay/modtronix,lcd2s.yaml
 create mode 100644 drivers/auxdisplay/hd44780_common.c
 create mode 100644 drivers/auxdisplay/hd44780_common.h
 create mode 100644 drivers/auxdisplay/lcd2s.c

-- 
2.28.0

[PATCH v5 01/25] auxdisplay: Use an enum for charlcd backlight on/off ops

[poeschel]

From: Lars Poeschel <poeschel@lemonage.de>

We use an enum for calling the functions in charlcd, that turn the
backlight on or off. This enum is generic and can be used for other
charlcd turn on / turn off operations as well.

Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
Changes in v5:
- Fix a commit message typo: of -> on
---
 drivers/auxdisplay/charlcd.c | 2 +-
 drivers/auxdisplay/charlcd.h | 7 ++++++-
 drivers/auxdisplay/hd44780.c | 2 +-
 drivers/auxdisplay/panel.c   | 2 +-
 4 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index 5aee0f546351..8aaee0fea9ab 100644
--- a/drivers/auxdisplay/charlcd.c
+++ b/drivers/auxdisplay/charlcd.c
@@ -101,7 +101,7 @@ static void long_sleep(int ms)
 }
 
 /* turn the backlight on or off */
-static void charlcd_backlight(struct charlcd *lcd, int on)
+static void charlcd_backlight(struct charlcd *lcd, enum charlcd_onoff on)
 {
 	struct charlcd_priv *priv = charlcd_to_priv(lcd);
 
diff --git a/drivers/auxdisplay/charlcd.h b/drivers/auxdisplay/charlcd.h
index 00911ad0f3de..c66f038e5d2b 100644
--- a/drivers/auxdisplay/charlcd.h
+++ b/drivers/auxdisplay/charlcd.h
@@ -9,6 +9,11 @@
 #ifndef _CHARLCD_H
 #define _CHARLCD_H
 
+enum charlcd_onoff {
+	CHARLCD_OFF = 0,
+	CHARLCD_ON,
+};
+
 struct charlcd {
 	const struct charlcd_ops *ops;
 	const unsigned char *char_conv;	/* Optional */
@@ -30,7 +35,7 @@ struct charlcd_ops {
 	/* Optional */
 	void (*write_cmd_raw4)(struct charlcd *lcd, int cmd);	/* 4-bit only */
 	void (*clear_fast)(struct charlcd *lcd);
-	void (*backlight)(struct charlcd *lcd, int on);
+	void (*backlight)(struct charlcd *lcd, enum charlcd_onoff on);
 };
 
 struct charlcd *charlcd_alloc(unsigned int drvdata_size);
diff --git a/drivers/auxdisplay/hd44780.c b/drivers/auxdisplay/hd44780.c
index bcbe13092327..5982158557bb 100644
--- a/drivers/auxdisplay/hd44780.c
+++ b/drivers/auxdisplay/hd44780.c
@@ -37,7 +37,7 @@ struct hd44780 {
 	struct gpio_desc *pins[PIN_NUM];
 };
 
-static void hd44780_backlight(struct charlcd *lcd, int on)
+static void hd44780_backlight(struct charlcd *lcd, enum charlcd_onoff on)
 {
 	struct hd44780 *hd = lcd->drvdata;
 
diff --git a/drivers/auxdisplay/panel.c b/drivers/auxdisplay/panel.c
index 1c82d824ae00..de623ae219f1 100644
--- a/drivers/auxdisplay/panel.c
+++ b/drivers/auxdisplay/panel.c
@@ -708,7 +708,7 @@ static void lcd_send_serial(int byte)
 }
 
 /* turn the backlight on or off */
-static void lcd_backlight(struct charlcd *charlcd, int on)
+static void lcd_backlight(struct charlcd *charlcd, enum charlcd_onoff on)
 {
 	if (lcd.pins.bl == PIN_NONE)
 		return;
-- 
2.28.0

[PATCH v5 02/25] auxdisplay: Introduce hd44780_common.[ch]

[poeschel]

From: Lars Poeschel <poeschel@lemonage.de>

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: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
Changes in v5:
- Remove some unnecessary newlines

Changes in v3:
- Fix some typos
---
 drivers/auxdisplay/Kconfig          | 20 ++++++++++++++
 drivers/auxdisplay/Makefile         |  1 +
 drivers/auxdisplay/hd44780.c        | 43 +++++++++++++++++++----------
 drivers/auxdisplay/hd44780_common.c | 19 +++++++++++++
 drivers/auxdisplay/hd44780_common.h |  7 +++++
 drivers/auxdisplay/panel.c          | 18 ++++++++++--
 6 files changed, 91 insertions(+), 17 deletions(-)
 create mode 100644 drivers/auxdisplay/hd44780_common.c
 create mode 100644 drivers/auxdisplay/hd44780_common.h

diff --git a/drivers/auxdisplay/Kconfig b/drivers/auxdisplay/Kconfig
index 81757eeded68..a56171d1a1ba 100644
--- a/drivers/auxdisplay/Kconfig
+++ b/drivers/auxdisplay/Kconfig
@@ -14,12 +14,31 @@ menuconfig AUXDISPLAY
 
 	  If you say N, all options in this submenu will be skipped and disabled.
 
+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.
+
 if AUXDISPLAY
 
 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
diff --git a/drivers/auxdisplay/Makefile b/drivers/auxdisplay/Makefile
index cf54b5efb07e..7e8a8c3eb3c3 100644
--- a/drivers/auxdisplay/Makefile
+++ b/drivers/auxdisplay/Makefile
@@ -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
diff --git a/drivers/auxdisplay/hd44780.c b/drivers/auxdisplay/hd44780.c
index 5982158557bb..271dba9cd108 100644
--- a/drivers/auxdisplay/hd44780.c
+++ b/drivers/auxdisplay/hd44780.c
@@ -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;
 }
 
diff --git a/drivers/auxdisplay/hd44780_common.c b/drivers/auxdisplay/hd44780_common.c
new file mode 100644
index 000000000000..2fdea29d6a8f
--- /dev/null
+++ b/drivers/auxdisplay/hd44780_common.c
@@ -0,0 +1,19 @@
+// 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");
diff --git a/drivers/auxdisplay/hd44780_common.h b/drivers/auxdisplay/hd44780_common.h
new file mode 100644
index 000000000000..974868f7529c
--- /dev/null
+++ b/drivers/auxdisplay/hd44780_common.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+struct hd44780_common {
+	void *hd44780;
+};
+
+struct hd44780_common *hd44780_common_alloc(void);
diff --git a/drivers/auxdisplay/panel.c b/drivers/auxdisplay/panel.c
index de623ae219f1..c3a60e190a7a 100644
--- a/drivers/auxdisplay/panel.c
+++ b/drivers/auxdisplay/panel.c
@@ -56,6 +56,7 @@
 #include <linux/uaccess.h>
 
 #include "charlcd.h"
+#include "hd44780_common.h"
 
 #define LCD_MAXBYTES		256	/* max burst write */
 
@@ -895,10 +896,20 @@ static const struct charlcd_ops charlcd_tilcd_ops = {
 static void lcd_init(void)
 {
 	struct charlcd *charlcd;
+	struct hd44780_common *hdc;
+
+	hdc = hd44780_common_alloc();
+	if (!hdc)
+		return;
 
 	charlcd = charlcd_alloc(0);
-	if (!charlcd)
+	if (!charlcd) {
+		kfree(hdc);
 		return;
+	}
+
+	hdc->hd44780 = &lcd;
+	charlcd->drvdata = hdc;
 
 	/*
 	 * Init lcd struct with load-time values to preserve exact
@@ -1620,7 +1631,7 @@ static void panel_attach(struct parport *port)
 	if (lcd.enabled)
 		charlcd_unregister(lcd.charlcd);
 err_unreg_device:
-	charlcd_free(lcd.charlcd);
+	kfree(lcd.charlcd);
 	lcd.charlcd = NULL;
 	parport_unregister_device(pprt);
 	pprt = NULL;
@@ -1647,7 +1658,8 @@ static void panel_detach(struct parport *port)
 	if (lcd.enabled) {
 		charlcd_unregister(lcd.charlcd);
 		lcd.initialized = false;
-		charlcd_free(lcd.charlcd);
+		kfree(lcd.charlcd->drvdata);
+		kfree(lcd.charlcd);
 		lcd.charlcd = NULL;
 	}
 
-- 
2.28.0

[PATCH v5 03/25] auxdisplay: Move hwidth and bwidth to struct hd44780_common

[poeschel]

From: Lars Poeschel <poeschel@lemonage.de>

hwidth is for the hardware buffer size and bwidth is for the buffer
width of one single line. This is specific to the hd44780 displays and
so it is moved out from charlcd to struct hd44780_common.

Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
 drivers/auxdisplay/charlcd.c        | 40 ++++++++++++-------------
 drivers/auxdisplay/charlcd.h        |  6 ++--
 drivers/auxdisplay/hd44780.c        | 24 +++++++++------
 drivers/auxdisplay/hd44780_common.c |  2 ++
 drivers/auxdisplay/hd44780_common.h |  5 ++++
 drivers/auxdisplay/panel.c          | 45 +++++++++++++++--------------
 6 files changed, 67 insertions(+), 55 deletions(-)

diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index 8aaee0fea9ab..02392336d7d3 100644
--- a/drivers/auxdisplay/charlcd.c
+++ b/drivers/auxdisplay/charlcd.c
@@ -21,9 +21,7 @@
 #include <generated/utsrelease.h>
 
 #include "charlcd.h"
-
-#define DEFAULT_LCD_BWIDTH      40
-#define DEFAULT_LCD_HWIDTH      64
+#include "hd44780_common.h"
 
 /* Keep the backlight on this many seconds for each flash */
 #define LCD_BL_TEMPO_PERIOD	4
@@ -151,18 +149,19 @@ EXPORT_SYMBOL_GPL(charlcd_poke);
 static void charlcd_gotoxy(struct charlcd *lcd)
 {
 	struct charlcd_priv *priv = charlcd_to_priv(lcd);
+	struct hd44780_common *hdc = lcd->drvdata;
 	unsigned int addr;
 
 	/*
 	 * we force the cursor to stay at the end of the
 	 * line if it wants to go farther
 	 */
-	addr = priv->addr.x < lcd->bwidth ? priv->addr.x & (lcd->hwidth - 1)
-					  : lcd->bwidth - 1;
+	addr = priv->addr.x < hdc->bwidth ? priv->addr.x & (hdc->hwidth - 1)
+					  : hdc->bwidth - 1;
 	if (priv->addr.y & 1)
-		addr += lcd->hwidth;
+		addr += hdc->hwidth;
 	if (priv->addr.y & 2)
-		addr += lcd->bwidth;
+		addr += hdc->bwidth;
 	lcd->ops->write_cmd(lcd, LCD_CMD_SET_DDRAM_ADDR | addr);
 }
 
@@ -178,21 +177,23 @@ static void charlcd_home(struct charlcd *lcd)
 static void charlcd_print(struct charlcd *lcd, char c)
 {
 	struct charlcd_priv *priv = charlcd_to_priv(lcd);
+	struct hd44780_common *hdc = lcd->drvdata;
 
-	if (priv->addr.x < lcd->bwidth) {
+	if (priv->addr.x < hdc->bwidth) {
 		if (lcd->char_conv)
 			c = lcd->char_conv[(unsigned char)c];
 		lcd->ops->write_data(lcd, c);
 		priv->addr.x++;
 
 		/* prevents the cursor from wrapping onto the next line */
-		if (priv->addr.x == lcd->bwidth)
+		if (priv->addr.x == hdc->bwidth)
 			charlcd_gotoxy(lcd);
 	}
 }
 
 static void charlcd_clear_fast(struct charlcd *lcd)
 {
+	struct hd44780_common *hdc = lcd->drvdata;
 	int pos;
 
 	charlcd_home(lcd);
@@ -200,7 +201,7 @@ static void charlcd_clear_fast(struct charlcd *lcd)
 	if (lcd->ops->clear_fast)
 		lcd->ops->clear_fast(lcd);
 	else
-		for (pos = 0; pos < min(2, lcd->height) * lcd->hwidth; pos++)
+		for (pos = 0; pos < min(2, lcd->height) * hdc->hwidth; pos++)
 			lcd->ops->write_data(lcd, ' ');
 
 	charlcd_home(lcd);
@@ -348,6 +349,7 @@ static bool parse_xy(const char *s, unsigned long *x, unsigned long *y)
 static inline int handle_lcd_special_code(struct charlcd *lcd)
 {
 	struct charlcd_priv *priv = charlcd_to_priv(lcd);
+	struct hd44780_common *hdc = lcd->drvdata;
 
 	/* LCD special codes */
 
@@ -413,7 +415,7 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 	case 'l':	/* Shift Cursor Left */
 		if (priv->addr.x > 0) {
 			/* back one char if not at end of line */
-			if (priv->addr.x < lcd->bwidth)
+			if (priv->addr.x < hdc->bwidth)
 				lcd->ops->write_cmd(lcd, LCD_CMD_SHIFT);
 			priv->addr.x--;
 		}
@@ -422,7 +424,7 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 	case 'r':	/* shift cursor right */
 		if (priv->addr.x < lcd->width) {
 			/* allow the cursor to pass the end of the line */
-			if (priv->addr.x < (lcd->bwidth - 1))
+			if (priv->addr.x < (hdc->bwidth - 1))
 				lcd->ops->write_cmd(lcd,
 					LCD_CMD_SHIFT | LCD_CMD_SHIFT_RIGHT);
 			priv->addr.x++;
@@ -442,7 +444,7 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 	case 'k': {	/* kill end of line */
 		int x;
 
-		for (x = priv->addr.x; x < lcd->bwidth; x++)
+		for (x = priv->addr.x; x < hdc->bwidth; x++)
 			lcd->ops->write_data(lcd, ' ');
 
 		/* restore cursor position */
@@ -554,6 +556,7 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 static void charlcd_write_char(struct charlcd *lcd, char c)
 {
 	struct charlcd_priv *priv = charlcd_to_priv(lcd);
+	struct hd44780_common *hdc = lcd->drvdata;
 
 	/* first, we'll test if we're in escape mode */
 	if ((c != '\n') && priv->esc_seq.len >= 0) {
@@ -577,7 +580,7 @@ static void charlcd_write_char(struct charlcd *lcd, char c)
 				 * check if we're not at the
 				 * end of the line
 				 */
-				if (priv->addr.x < lcd->bwidth)
+				if (priv->addr.x < hdc->bwidth)
 					/* back one char */
 					lcd->ops->write_cmd(lcd, LCD_CMD_SHIFT);
 				priv->addr.x--;
@@ -596,7 +599,7 @@ static void charlcd_write_char(struct charlcd *lcd, char c)
 			 * flush the remainder of the current line and
 			 * go to the beginning of the next line
 			 */
-			for (; priv->addr.x < lcd->bwidth; priv->addr.x++)
+			for (; priv->addr.x < hdc->bwidth; priv->addr.x++)
 				lcd->ops->write_data(lcd, ' ');
 			priv->addr.x = 0;
 			priv->addr.y = (priv->addr.y + 1) % lcd->height;
@@ -779,12 +782,12 @@ static int charlcd_init(struct charlcd *lcd)
 	return 0;
 }
 
-struct charlcd *charlcd_alloc(unsigned int drvdata_size)
+struct charlcd *charlcd_alloc(void)
 {
 	struct charlcd_priv *priv;
 	struct charlcd *lcd;
 
-	priv = kzalloc(sizeof(*priv) + drvdata_size, GFP_KERNEL);
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 	if (!priv)
 		return NULL;
 
@@ -792,9 +795,6 @@ struct charlcd *charlcd_alloc(unsigned int drvdata_size)
 
 	lcd = &priv->lcd;
 	lcd->ifwidth = 8;
-	lcd->bwidth = DEFAULT_LCD_BWIDTH;
-	lcd->hwidth = DEFAULT_LCD_HWIDTH;
-	lcd->drvdata = priv->drvdata;
 
 	return lcd;
 }
diff --git a/drivers/auxdisplay/charlcd.h b/drivers/auxdisplay/charlcd.h
index c66f038e5d2b..2a12d07705a3 100644
--- a/drivers/auxdisplay/charlcd.h
+++ b/drivers/auxdisplay/charlcd.h
@@ -21,10 +21,8 @@ struct charlcd {
 	int ifwidth;			/* 4-bit or 8-bit (default) */
 	int height;
 	int width;
-	int bwidth;			/* Default set by charlcd_alloc() */
-	int hwidth;			/* Default set by charlcd_alloc() */
 
-	void *drvdata;			/* Set by charlcd_alloc() */
+	void *drvdata;
 };
 
 struct charlcd_ops {
@@ -38,7 +36,7 @@ struct charlcd_ops {
 	void (*backlight)(struct charlcd *lcd, enum charlcd_onoff on);
 };
 
-struct charlcd *charlcd_alloc(unsigned int drvdata_size);
+struct charlcd *charlcd_alloc(void);
 void charlcd_free(struct charlcd *lcd);
 
 int charlcd_register(struct charlcd *lcd);
diff --git a/drivers/auxdisplay/hd44780.c b/drivers/auxdisplay/hd44780.c
index 271dba9cd108..0603af8f2336 100644
--- a/drivers/auxdisplay/hd44780.c
+++ b/drivers/auxdisplay/hd44780.c
@@ -40,7 +40,8 @@ struct hd44780 {
 
 static void hd44780_backlight(struct charlcd *lcd, enum charlcd_onoff on)
 {
-	struct hd44780 *hd = lcd->drvdata;
+	struct hd44780_common *hdc = lcd->drvdata;
+	struct hd44780 *hd = hdc->hd44780;
 
 	if (hd->pins[PIN_CTRL_BL])
 		gpiod_set_value_cansleep(hd->pins[PIN_CTRL_BL], on);
@@ -104,7 +105,8 @@ static void hd44780_write_gpio4(struct hd44780 *hd, u8 val, unsigned int rs)
 /* Send a command to the LCD panel in 8 bit GPIO mode */
 static void hd44780_write_cmd_gpio8(struct charlcd *lcd, int cmd)
 {
-	struct hd44780 *hd = lcd->drvdata;
+	struct hd44780_common *hdc = lcd->drvdata;
+	struct hd44780 *hd = hdc->hd44780;
 
 	hd44780_write_gpio8(hd, cmd, 0);
 
@@ -115,7 +117,8 @@ static void hd44780_write_cmd_gpio8(struct charlcd *lcd, int cmd)
 /* Send data to the LCD panel in 8 bit GPIO mode */
 static void hd44780_write_data_gpio8(struct charlcd *lcd, int data)
 {
-	struct hd44780 *hd = lcd->drvdata;
+	struct hd44780_common *hdc = lcd->drvdata;
+	struct hd44780 *hd = hdc->hd44780;
 
 	hd44780_write_gpio8(hd, data, 1);
 
@@ -132,7 +135,8 @@ static const struct charlcd_ops hd44780_ops_gpio8 = {
 /* Send a command to the LCD panel in 4 bit GPIO mode */
 static void hd44780_write_cmd_gpio4(struct charlcd *lcd, int cmd)
 {
-	struct hd44780 *hd = lcd->drvdata;
+	struct hd44780_common *hdc = lcd->drvdata;
+	struct hd44780 *hd = hdc->hd44780;
 
 	hd44780_write_gpio4(hd, cmd, 0);
 
@@ -144,7 +148,8 @@ static void hd44780_write_cmd_gpio4(struct charlcd *lcd, int cmd)
 static void hd44780_write_cmd_raw_gpio4(struct charlcd *lcd, int cmd)
 {
 	DECLARE_BITMAP(values, 6); /* for DATA[4-7], RS, RW */
-	struct hd44780 *hd = lcd->drvdata;
+	struct hd44780_common *hdc = lcd->drvdata;
+	struct hd44780 *hd = hdc->hd44780;
 	unsigned int n;
 
 	/* Command nibble + RS, RW */
@@ -160,7 +165,8 @@ static void hd44780_write_cmd_raw_gpio4(struct charlcd *lcd, int cmd)
 /* Send data to the LCD panel in 4 bit GPIO mode */
 static void hd44780_write_data_gpio4(struct charlcd *lcd, int data)
 {
-	struct hd44780 *hd = lcd->drvdata;
+	struct hd44780_common *hdc = lcd->drvdata;
+	struct hd44780 *hd = hdc->hd44780;
 
 	hd44780_write_gpio4(hd, data, 1);
 
@@ -204,7 +210,7 @@ static int hd44780_probe(struct platform_device *pdev)
 	if (!hdc)
 		return -ENOMEM;
 
-	lcd = charlcd_alloc(sizeof(struct hd44780));
+	lcd = charlcd_alloc();
 	if (!lcd)
 		goto fail1;
 
@@ -264,10 +270,10 @@ static int hd44780_probe(struct platform_device *pdev)
 	 * usually equal to the display width
 	 */
 	if (lcd->height > 2)
-		lcd->bwidth = lcd->width;
+		hdc->bwidth = lcd->width;
 
 	/* Optional properties */
-	device_property_read_u32(dev, "internal-buffer-width", &lcd->bwidth);
+	device_property_read_u32(dev, "internal-buffer-width", &hdc->bwidth);
 
 	lcd->ifwidth = ifwidth;
 	lcd->ops = ifwidth == 8 ? &hd44780_ops_gpio8 : &hd44780_ops_gpio4;
diff --git a/drivers/auxdisplay/hd44780_common.c b/drivers/auxdisplay/hd44780_common.c
index 2fdea29d6a8f..3a05fd30cae0 100644
--- a/drivers/auxdisplay/hd44780_common.c
+++ b/drivers/auxdisplay/hd44780_common.c
@@ -12,6 +12,8 @@ struct hd44780_common *hd44780_common_alloc(void)
 	if (!hd)
 		return NULL;
 
+	hd->bwidth = DEFAULT_LCD_BWIDTH;
+	hd->hwidth = DEFAULT_LCD_HWIDTH;
 	return hd;
 }
 EXPORT_SYMBOL_GPL(hd44780_common_alloc);
diff --git a/drivers/auxdisplay/hd44780_common.h b/drivers/auxdisplay/hd44780_common.h
index 974868f7529c..9647d24c4490 100644
--- a/drivers/auxdisplay/hd44780_common.h
+++ b/drivers/auxdisplay/hd44780_common.h
@@ -1,6 +1,11 @@
 /* SPDX-License-Identifier: GPL-2.0-or-later */
 
+#define DEFAULT_LCD_BWIDTH      40
+#define DEFAULT_LCD_HWIDTH      64
+
 struct hd44780_common {
+	int bwidth;			/* Default set by hd44780_alloc() */
+	int hwidth;			/* Default set by hd44780_alloc() */
 	void *hd44780;
 };
 
diff --git a/drivers/auxdisplay/panel.c b/drivers/auxdisplay/panel.c
index c3a60e190a7a..cec6b729d668 100644
--- a/drivers/auxdisplay/panel.c
+++ b/drivers/auxdisplay/panel.c
@@ -299,8 +299,6 @@ static unsigned char lcd_bits[LCD_PORTS][LCD_BITS][BIT_STATES];
 #define DEFAULT_LCD_TYPE        LCD_TYPE_OLD
 #define DEFAULT_LCD_HEIGHT      2
 #define DEFAULT_LCD_WIDTH       40
-#define DEFAULT_LCD_BWIDTH      40
-#define DEFAULT_LCD_HWIDTH      64
 #define DEFAULT_LCD_CHARSET     LCD_CHARSET_NORMAL
 #define DEFAULT_LCD_PROTO       LCD_PROTO_PARALLEL
 
@@ -813,10 +811,11 @@ static void lcd_write_data_tilcd(struct charlcd *charlcd, int data)
 /* fills the display with spaces and resets X/Y */
 static void lcd_clear_fast_s(struct charlcd *charlcd)
 {
+	struct hd44780_common *hdc = charlcd->drvdata;
 	int pos;
 
 	spin_lock_irq(&pprt_lock);
-	for (pos = 0; pos < charlcd->height * charlcd->hwidth; pos++) {
+	for (pos = 0; pos < charlcd->height * hdc->hwidth; pos++) {
 		lcd_send_serial(0x5F);	/* R/W=W, RS=1 */
 		lcd_send_serial(' ' & 0x0F);
 		lcd_send_serial((' ' >> 4) & 0x0F);
@@ -829,10 +828,11 @@ static void lcd_clear_fast_s(struct charlcd *charlcd)
 /* fills the display with spaces and resets X/Y */
 static void lcd_clear_fast_p8(struct charlcd *charlcd)
 {
+	struct hd44780_common *hdc = charlcd->drvdata;
 	int pos;
 
 	spin_lock_irq(&pprt_lock);
-	for (pos = 0; pos < charlcd->height * charlcd->hwidth; pos++) {
+	for (pos = 0; pos < charlcd->height * hdc->hwidth; pos++) {
 		/* present the data to the data port */
 		w_dtr(pprt, ' ');
 
@@ -859,10 +859,11 @@ static void lcd_clear_fast_p8(struct charlcd *charlcd)
 /* fills the display with spaces and resets X/Y */
 static void lcd_clear_fast_tilcd(struct charlcd *charlcd)
 {
+	struct hd44780_common *hdc = charlcd->drvdata;
 	int pos;
 
 	spin_lock_irq(&pprt_lock);
-	for (pos = 0; pos < charlcd->height * charlcd->hwidth; pos++) {
+	for (pos = 0; pos < charlcd->height * hdc->hwidth; pos++) {
 		/* present the data to the data port */
 		w_dtr(pprt, ' ');
 		udelay(60);
@@ -902,7 +903,7 @@ static void lcd_init(void)
 	if (!hdc)
 		return;
 
-	charlcd = charlcd_alloc(0);
+	charlcd = charlcd_alloc();
 	if (!charlcd) {
 		kfree(hdc);
 		return;
@@ -917,8 +918,8 @@ static void lcd_init(void)
 	 */
 	charlcd->height = lcd_height;
 	charlcd->width = lcd_width;
-	charlcd->bwidth = lcd_bwidth;
-	charlcd->hwidth = lcd_hwidth;
+	hdc->bwidth = lcd_bwidth;
+	hdc->hwidth = lcd_hwidth;
 
 	switch (selected_lcd_type) {
 	case LCD_TYPE_OLD:
@@ -929,8 +930,8 @@ static void lcd_init(void)
 		lcd.pins.rs = PIN_AUTOLF;
 
 		charlcd->width = 40;
-		charlcd->bwidth = 40;
-		charlcd->hwidth = 64;
+		hdc->bwidth = 40;
+		hdc->hwidth = 64;
 		charlcd->height = 2;
 		break;
 	case LCD_TYPE_KS0074:
@@ -942,8 +943,8 @@ static void lcd_init(void)
 		lcd.pins.da = PIN_D0;
 
 		charlcd->width = 16;
-		charlcd->bwidth = 40;
-		charlcd->hwidth = 16;
+		hdc->bwidth = 40;
+		hdc->hwidth = 16;
 		charlcd->height = 2;
 		break;
 	case LCD_TYPE_NEXCOM:
@@ -955,8 +956,8 @@ static void lcd_init(void)
 		lcd.pins.rw = PIN_INITP;
 
 		charlcd->width = 16;
-		charlcd->bwidth = 40;
-		charlcd->hwidth = 64;
+		hdc->bwidth = 40;
+		hdc->hwidth = 64;
 		charlcd->height = 2;
 		break;
 	case LCD_TYPE_CUSTOM:
@@ -974,8 +975,8 @@ static void lcd_init(void)
 		lcd.pins.rs = PIN_SELECP;
 
 		charlcd->width = 16;
-		charlcd->bwidth = 40;
-		charlcd->hwidth = 64;
+		hdc->bwidth = 40;
+		hdc->hwidth = 64;
 		charlcd->height = 2;
 		break;
 	}
@@ -986,9 +987,9 @@ static void lcd_init(void)
 	if (lcd_width != NOT_SET)
 		charlcd->width = lcd_width;
 	if (lcd_bwidth != NOT_SET)
-		charlcd->bwidth = lcd_bwidth;
+		hdc->bwidth = lcd_bwidth;
 	if (lcd_hwidth != NOT_SET)
-		charlcd->hwidth = lcd_hwidth;
+		hdc->hwidth = lcd_hwidth;
 	if (lcd_charset != NOT_SET)
 		lcd.charset = lcd_charset;
 	if (lcd_proto != NOT_SET)
@@ -1009,10 +1010,10 @@ static void lcd_init(void)
 	/* this is used to catch wrong and default values */
 	if (charlcd->width <= 0)
 		charlcd->width = DEFAULT_LCD_WIDTH;
-	if (charlcd->bwidth <= 0)
-		charlcd->bwidth = DEFAULT_LCD_BWIDTH;
-	if (charlcd->hwidth <= 0)
-		charlcd->hwidth = DEFAULT_LCD_HWIDTH;
+	if (hdc->bwidth <= 0)
+		hdc->bwidth = DEFAULT_LCD_BWIDTH;
+	if (hdc->hwidth <= 0)
+		hdc->hwidth = DEFAULT_LCD_HWIDTH;
 	if (charlcd->height <= 0)
 		charlcd->height = DEFAULT_LCD_HEIGHT;
 
-- 
2.28.0

[PATCH v5 04/25] auxdisplay: Move ifwidth to struct hd44780_common

[poeschel]

From: Lars Poeschel <poeschel@lemonage.de>

Move struct charlcd member ifwidth to our new struct hd44780_common.
ifwidth is hd44780 device specific and is used by two drivers at the
moment, so we move it to a common place, where both can use this.

Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
 drivers/auxdisplay/charlcd.c        | 12 ++++++------
 drivers/auxdisplay/charlcd.h        |  1 -
 drivers/auxdisplay/hd44780.c        |  2 +-
 drivers/auxdisplay/hd44780_common.c |  1 +
 drivers/auxdisplay/hd44780_common.h |  1 +
 5 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index 02392336d7d3..59e0a815bf3d 100644
--- a/drivers/auxdisplay/charlcd.c
+++ b/drivers/auxdisplay/charlcd.c
@@ -223,9 +223,10 @@ static int charlcd_init_display(struct charlcd *lcd)
 {
 	void (*write_cmd_raw)(struct charlcd *lcd, int cmd);
 	struct charlcd_priv *priv = charlcd_to_priv(lcd);
+	struct hd44780_common *hdc = lcd->drvdata;
 	u8 init;
 
-	if (lcd->ifwidth != 4 && lcd->ifwidth != 8)
+	if (hdc->ifwidth != 4 && hdc->ifwidth != 8)
 		return -EINVAL;
 
 	priv->flags = ((lcd->height > 1) ? LCD_FLAG_N : 0) | LCD_FLAG_D |
@@ -238,7 +239,7 @@ static int charlcd_init_display(struct charlcd *lcd)
 	 * the LCD is in 8-bit mode afterwards
 	 */
 	init = LCD_CMD_FUNCTION_SET | LCD_CMD_DATA_LEN_8BITS;
-	if (lcd->ifwidth == 4) {
+	if (hdc->ifwidth == 4) {
 		init >>= 4;
 		write_cmd_raw = lcd->ops->write_cmd_raw4;
 	} else {
@@ -251,7 +252,7 @@ static int charlcd_init_display(struct charlcd *lcd)
 	write_cmd_raw(lcd, init);
 	long_sleep(10);
 
-	if (lcd->ifwidth == 4) {
+	if (hdc->ifwidth == 4) {
 		/* Switch to 4-bit mode, 1 line, small fonts */
 		lcd->ops->write_cmd_raw4(lcd, LCD_CMD_FUNCTION_SET >> 4);
 		long_sleep(10);
@@ -260,7 +261,7 @@ static int charlcd_init_display(struct charlcd *lcd)
 	/* set font height and lines number */
 	lcd->ops->write_cmd(lcd,
 		LCD_CMD_FUNCTION_SET |
-		((lcd->ifwidth == 8) ? LCD_CMD_DATA_LEN_8BITS : 0) |
+		((hdc->ifwidth == 8) ? LCD_CMD_DATA_LEN_8BITS : 0) |
 		((priv->flags & LCD_FLAG_F) ? LCD_CMD_FONT_5X10_DOTS : 0) |
 		((priv->flags & LCD_FLAG_N) ? LCD_CMD_TWO_LINES : 0));
 	long_sleep(10);
@@ -543,7 +544,7 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 	else if ((oldflags ^ priv->flags) & (LCD_FLAG_F | LCD_FLAG_N))
 		lcd->ops->write_cmd(lcd,
 			LCD_CMD_FUNCTION_SET |
-			((lcd->ifwidth == 8) ? LCD_CMD_DATA_LEN_8BITS : 0) |
+			((hdc->ifwidth == 8) ? LCD_CMD_DATA_LEN_8BITS : 0) |
 			((priv->flags & LCD_FLAG_F) ? LCD_CMD_FONT_5X10_DOTS : 0) |
 			((priv->flags & LCD_FLAG_N) ? LCD_CMD_TWO_LINES : 0));
 	/* check whether L flag was changed */
@@ -794,7 +795,6 @@ struct charlcd *charlcd_alloc(void)
 	priv->esc_seq.len = -1;
 
 	lcd = &priv->lcd;
-	lcd->ifwidth = 8;
 
 	return lcd;
 }
diff --git a/drivers/auxdisplay/charlcd.h b/drivers/auxdisplay/charlcd.h
index 2a12d07705a3..5dce9dd36562 100644
--- a/drivers/auxdisplay/charlcd.h
+++ b/drivers/auxdisplay/charlcd.h
@@ -18,7 +18,6 @@ struct charlcd {
 	const struct charlcd_ops *ops;
 	const unsigned char *char_conv;	/* Optional */
 
-	int ifwidth;			/* 4-bit or 8-bit (default) */
 	int height;
 	int width;
 
diff --git a/drivers/auxdisplay/hd44780.c b/drivers/auxdisplay/hd44780.c
index 0603af8f2336..f6786239c36f 100644
--- a/drivers/auxdisplay/hd44780.c
+++ b/drivers/auxdisplay/hd44780.c
@@ -275,7 +275,7 @@ static int hd44780_probe(struct platform_device *pdev)
 	/* Optional properties */
 	device_property_read_u32(dev, "internal-buffer-width", &hdc->bwidth);
 
-	lcd->ifwidth = ifwidth;
+	hdc->ifwidth = ifwidth;
 	lcd->ops = ifwidth == 8 ? &hd44780_ops_gpio8 : &hd44780_ops_gpio4;
 
 	ret = charlcd_register(lcd);
diff --git a/drivers/auxdisplay/hd44780_common.c b/drivers/auxdisplay/hd44780_common.c
index 3a05fd30cae0..4968461f0c4a 100644
--- a/drivers/auxdisplay/hd44780_common.c
+++ b/drivers/auxdisplay/hd44780_common.c
@@ -12,6 +12,7 @@ struct hd44780_common *hd44780_common_alloc(void)
 	if (!hd)
 		return NULL;
 
+	hd->ifwidth = 8;
 	hd->bwidth = DEFAULT_LCD_BWIDTH;
 	hd->hwidth = DEFAULT_LCD_HWIDTH;
 	return hd;
diff --git a/drivers/auxdisplay/hd44780_common.h b/drivers/auxdisplay/hd44780_common.h
index 9647d24c4490..54cbe5a489d7 100644
--- a/drivers/auxdisplay/hd44780_common.h
+++ b/drivers/auxdisplay/hd44780_common.h
@@ -4,6 +4,7 @@
 #define DEFAULT_LCD_HWIDTH      64
 
 struct hd44780_common {
+	int ifwidth;			/* 4-bit or 8-bit (default) */
 	int bwidth;			/* Default set by hd44780_alloc() */
 	int hwidth;			/* Default set by hd44780_alloc() */
 	void *hd44780;
-- 
2.28.0

[PATCH v5 05/25] auxdisplay: Move write_data pointer to hd44780_common

[poeschel]

From: Lars Poeschel <poeschel@lemonage.de>

This moves the write_data function pointer from struct charlcd_ops to
struct hd44780_common. This is the function that actually writes the
character to the display. This hd44780 hardware specific function is
used by two drivers at the moment.

Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
 drivers/auxdisplay/charlcd.c        | 12 ++++++------
 drivers/auxdisplay/charlcd.h        |  1 -
 drivers/auxdisplay/hd44780.c        | 16 +++++++++-------
 drivers/auxdisplay/hd44780_common.h |  1 +
 drivers/auxdisplay/panel.c          | 12 ++++++------
 5 files changed, 22 insertions(+), 20 deletions(-)

diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index 59e0a815bf3d..df54078656c1 100644
--- a/drivers/auxdisplay/charlcd.c
+++ b/drivers/auxdisplay/charlcd.c
@@ -182,7 +182,7 @@ static void charlcd_print(struct charlcd *lcd, char c)
 	if (priv->addr.x < hdc->bwidth) {
 		if (lcd->char_conv)
 			c = lcd->char_conv[(unsigned char)c];
-		lcd->ops->write_data(lcd, c);
+		hdc->write_data(hdc, c);
 		priv->addr.x++;
 
 		/* prevents the cursor from wrapping onto the next line */
@@ -202,7 +202,7 @@ static void charlcd_clear_fast(struct charlcd *lcd)
 		lcd->ops->clear_fast(lcd);
 	else
 		for (pos = 0; pos < min(2, lcd->height) * hdc->hwidth; pos++)
-			lcd->ops->write_data(lcd, ' ');
+			hdc->write_data(hdc, ' ');
 
 	charlcd_home(lcd);
 }
@@ -446,7 +446,7 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 		int x;
 
 		for (x = priv->addr.x; x < hdc->bwidth; x++)
-			lcd->ops->write_data(lcd, ' ');
+			hdc->write_data(hdc, ' ');
 
 		/* restore cursor position */
 		charlcd_gotoxy(lcd);
@@ -505,7 +505,7 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 
 		lcd->ops->write_cmd(lcd, LCD_CMD_SET_CGRAM_ADDR | (cgaddr * 8));
 		for (addr = 0; addr < cgoffset; addr++)
-			lcd->ops->write_data(lcd, cgbytes[addr]);
+			hdc->write_data(hdc, cgbytes[addr]);
 
 		/* ensures that we stop writing to CGRAM */
 		charlcd_gotoxy(lcd);
@@ -587,7 +587,7 @@ static void charlcd_write_char(struct charlcd *lcd, char c)
 				priv->addr.x--;
 			}
 			/* replace with a space */
-			lcd->ops->write_data(lcd, ' ');
+			hdc->write_data(hdc, ' ');
 			/* back one char again */
 			lcd->ops->write_cmd(lcd, LCD_CMD_SHIFT);
 			break;
@@ -601,7 +601,7 @@ static void charlcd_write_char(struct charlcd *lcd, char c)
 			 * go to the beginning of the next line
 			 */
 			for (; priv->addr.x < hdc->bwidth; priv->addr.x++)
-				lcd->ops->write_data(lcd, ' ');
+				hdc->write_data(hdc, ' ');
 			priv->addr.x = 0;
 			priv->addr.y = (priv->addr.y + 1) % lcd->height;
 			charlcd_gotoxy(lcd);
diff --git a/drivers/auxdisplay/charlcd.h b/drivers/auxdisplay/charlcd.h
index 5dce9dd36562..fba4f2cd42c4 100644
--- a/drivers/auxdisplay/charlcd.h
+++ b/drivers/auxdisplay/charlcd.h
@@ -27,7 +27,6 @@ struct charlcd {
 struct charlcd_ops {
 	/* Required */
 	void (*write_cmd)(struct charlcd *lcd, int cmd);
-	void (*write_data)(struct charlcd *lcd, int data);
 
 	/* Optional */
 	void (*write_cmd_raw4)(struct charlcd *lcd, int cmd);	/* 4-bit only */
diff --git a/drivers/auxdisplay/hd44780.c b/drivers/auxdisplay/hd44780.c
index f6786239c36f..922f0e0d2e6d 100644
--- a/drivers/auxdisplay/hd44780.c
+++ b/drivers/auxdisplay/hd44780.c
@@ -115,9 +115,8 @@ static void hd44780_write_cmd_gpio8(struct charlcd *lcd, int cmd)
 }
 
 /* Send data to the LCD panel in 8 bit GPIO mode */
-static void hd44780_write_data_gpio8(struct charlcd *lcd, int data)
+static void hd44780_write_data_gpio8(struct hd44780_common *hdc, int data)
 {
-	struct hd44780_common *hdc = lcd->drvdata;
 	struct hd44780 *hd = hdc->hd44780;
 
 	hd44780_write_gpio8(hd, data, 1);
@@ -128,7 +127,6 @@ static void hd44780_write_data_gpio8(struct charlcd *lcd, int data)
 
 static const struct charlcd_ops hd44780_ops_gpio8 = {
 	.write_cmd	= hd44780_write_cmd_gpio8,
-	.write_data	= hd44780_write_data_gpio8,
 	.backlight	= hd44780_backlight,
 };
 
@@ -163,9 +161,8 @@ static void hd44780_write_cmd_raw_gpio4(struct charlcd *lcd, int cmd)
 }
 
 /* Send data to the LCD panel in 4 bit GPIO mode */
-static void hd44780_write_data_gpio4(struct charlcd *lcd, int data)
+static void hd44780_write_data_gpio4(struct hd44780_common *hdc, int data)
 {
-	struct hd44780_common *hdc = lcd->drvdata;
 	struct hd44780 *hd = hdc->hd44780;
 
 	hd44780_write_gpio4(hd, data, 1);
@@ -177,7 +174,6 @@ static void hd44780_write_data_gpio4(struct charlcd *lcd, int data)
 static const struct charlcd_ops hd44780_ops_gpio4 = {
 	.write_cmd	= hd44780_write_cmd_gpio4,
 	.write_cmd_raw4	= hd44780_write_cmd_raw_gpio4,
-	.write_data	= hd44780_write_data_gpio4,
 	.backlight	= hd44780_backlight,
 };
 
@@ -276,7 +272,13 @@ static int hd44780_probe(struct platform_device *pdev)
 	device_property_read_u32(dev, "internal-buffer-width", &hdc->bwidth);
 
 	hdc->ifwidth = ifwidth;
-	lcd->ops = ifwidth == 8 ? &hd44780_ops_gpio8 : &hd44780_ops_gpio4;
+	if (ifwidth == 8) {
+		lcd->ops = &hd44780_ops_gpio8;
+		hdc->write_data = hd44780_write_data_gpio8;
+	} else {
+		lcd->ops = &hd44780_ops_gpio4;
+		hdc->write_data = hd44780_write_data_gpio4;
+	}
 
 	ret = charlcd_register(lcd);
 	if (ret)
diff --git a/drivers/auxdisplay/hd44780_common.h b/drivers/auxdisplay/hd44780_common.h
index 54cbe5a489d7..bcc13421bf45 100644
--- a/drivers/auxdisplay/hd44780_common.h
+++ b/drivers/auxdisplay/hd44780_common.h
@@ -7,6 +7,7 @@ struct hd44780_common {
 	int ifwidth;			/* 4-bit or 8-bit (default) */
 	int bwidth;			/* Default set by hd44780_alloc() */
 	int hwidth;			/* Default set by hd44780_alloc() */
+	void (*write_data)(struct hd44780_common *hdc, int data);
 	void *hd44780;
 };
 
diff --git a/drivers/auxdisplay/panel.c b/drivers/auxdisplay/panel.c
index cec6b729d668..15100d21a6e9 100644
--- a/drivers/auxdisplay/panel.c
+++ b/drivers/auxdisplay/panel.c
@@ -734,7 +734,7 @@ static void lcd_write_cmd_s(struct charlcd *charlcd, int cmd)
 }
 
 /* send data to the LCD panel in serial mode */
-static void lcd_write_data_s(struct charlcd *charlcd, int data)
+static void lcd_write_data_s(struct hd44780_common *hdc, int data)
 {
 	spin_lock_irq(&pprt_lock);
 	lcd_send_serial(0x5F);	/* R/W=W, RS=1 */
@@ -767,7 +767,7 @@ static void lcd_write_cmd_p8(struct charlcd *charlcd, int cmd)
 }
 
 /* send data to the LCD panel in 8 bits parallel mode */
-static void lcd_write_data_p8(struct charlcd *charlcd, int data)
+static void lcd_write_data_p8(struct hd44780_common *hdc, int data)
 {
 	spin_lock_irq(&pprt_lock);
 	/* present the data to the data port */
@@ -799,7 +799,7 @@ static void lcd_write_cmd_tilcd(struct charlcd *charlcd, int cmd)
 }
 
 /* send data to the TI LCD panel */
-static void lcd_write_data_tilcd(struct charlcd *charlcd, int data)
+static void lcd_write_data_tilcd(struct hd44780_common *hdc, int data)
 {
 	spin_lock_irq(&pprt_lock);
 	/* present the data to the data port */
@@ -874,21 +874,18 @@ static void lcd_clear_fast_tilcd(struct charlcd *charlcd)
 
 static const struct charlcd_ops charlcd_serial_ops = {
 	.write_cmd	= lcd_write_cmd_s,
-	.write_data	= lcd_write_data_s,
 	.clear_fast	= lcd_clear_fast_s,
 	.backlight	= lcd_backlight,
 };
 
 static const struct charlcd_ops charlcd_parallel_ops = {
 	.write_cmd	= lcd_write_cmd_p8,
-	.write_data	= lcd_write_data_p8,
 	.clear_fast	= lcd_clear_fast_p8,
 	.backlight	= lcd_backlight,
 };
 
 static const struct charlcd_ops charlcd_tilcd_ops = {
 	.write_cmd	= lcd_write_cmd_tilcd,
-	.write_data	= lcd_write_data_tilcd,
 	.clear_fast	= lcd_clear_fast_tilcd,
 	.backlight	= lcd_backlight,
 };
@@ -1019,6 +1016,7 @@ static void lcd_init(void)
 
 	if (lcd.proto == LCD_PROTO_SERIAL) {	/* SERIAL */
 		charlcd->ops = &charlcd_serial_ops;
+		hdc->write_data = lcd_write_data_s;
 
 		if (lcd.pins.cl == PIN_NOT_SET)
 			lcd.pins.cl = DEFAULT_LCD_PIN_SCL;
@@ -1027,6 +1025,7 @@ static void lcd_init(void)
 
 	} else if (lcd.proto == LCD_PROTO_PARALLEL) {	/* PARALLEL */
 		charlcd->ops = &charlcd_parallel_ops;
+		hdc->write_data = lcd_write_data_p8;
 
 		if (lcd.pins.e == PIN_NOT_SET)
 			lcd.pins.e = DEFAULT_LCD_PIN_E;
@@ -1036,6 +1035,7 @@ static void lcd_init(void)
 			lcd.pins.rw = DEFAULT_LCD_PIN_RW;
 	} else {
 		charlcd->ops = &charlcd_tilcd_ops;
+		hdc->write_data = lcd_write_data_tilcd;
 	}
 
 	if (lcd.pins.bl == PIN_NOT_SET)
-- 
2.28.0

[PATCH v5 06/25] auxdisplay: Move write_cmd pointers to hd44780 drivers

[poeschel]

From: Lars Poeschel <poeschel@lemonage.de>

The write_cmd function is used to send commands to hd44780 displays.
The individual hd44780 drivers then implement their appropriate way of
doing this with their supported displays. So we move this pointer so
hd44780_common.

Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
 drivers/auxdisplay/charlcd.c        | 45 +++++++++++++++--------------
 drivers/auxdisplay/charlcd.h        |  5 ----
 drivers/auxdisplay/hd44780.c        | 15 ++++------
 drivers/auxdisplay/hd44780_common.h |  3 ++
 drivers/auxdisplay/panel.c          | 12 ++++----
 5 files changed, 38 insertions(+), 42 deletions(-)

diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index df54078656c1..ce6622f71c34 100644
--- a/drivers/auxdisplay/charlcd.c
+++ b/drivers/auxdisplay/charlcd.c
@@ -162,7 +162,7 @@ static void charlcd_gotoxy(struct charlcd *lcd)
 		addr += hdc->hwidth;
 	if (priv->addr.y & 2)
 		addr += hdc->bwidth;
-	lcd->ops->write_cmd(lcd, LCD_CMD_SET_DDRAM_ADDR | addr);
+	hdc->write_cmd(hdc, LCD_CMD_SET_DDRAM_ADDR | addr);
 }
 
 static void charlcd_home(struct charlcd *lcd)
@@ -211,8 +211,9 @@ static void charlcd_clear_fast(struct charlcd *lcd)
 static void charlcd_clear_display(struct charlcd *lcd)
 {
 	struct charlcd_priv *priv = charlcd_to_priv(lcd);
+	struct hd44780_common *hdc = lcd->drvdata;
 
-	lcd->ops->write_cmd(lcd, LCD_CMD_DISPLAY_CLEAR);
+	hdc->write_cmd(hdc, LCD_CMD_DISPLAY_CLEAR);
 	priv->addr.x = 0;
 	priv->addr.y = 0;
 	/* we must wait a few milliseconds (15) */
@@ -221,7 +222,7 @@ static void charlcd_clear_display(struct charlcd *lcd)
 
 static int charlcd_init_display(struct charlcd *lcd)
 {
-	void (*write_cmd_raw)(struct charlcd *lcd, int cmd);
+	void (*write_cmd_raw)(struct hd44780_common *hdc, int cmd);
 	struct charlcd_priv *priv = charlcd_to_priv(lcd);
 	struct hd44780_common *hdc = lcd->drvdata;
 	u8 init;
@@ -241,25 +242,25 @@ static int charlcd_init_display(struct charlcd *lcd)
 	init = LCD_CMD_FUNCTION_SET | LCD_CMD_DATA_LEN_8BITS;
 	if (hdc->ifwidth == 4) {
 		init >>= 4;
-		write_cmd_raw = lcd->ops->write_cmd_raw4;
+		write_cmd_raw = hdc->write_cmd_raw4;
 	} else {
-		write_cmd_raw = lcd->ops->write_cmd;
+		write_cmd_raw = hdc->write_cmd;
 	}
-	write_cmd_raw(lcd, init);
+	write_cmd_raw(hdc, init);
 	long_sleep(10);
-	write_cmd_raw(lcd, init);
+	write_cmd_raw(hdc, init);
 	long_sleep(10);
-	write_cmd_raw(lcd, init);
+	write_cmd_raw(hdc, init);
 	long_sleep(10);
 
 	if (hdc->ifwidth == 4) {
 		/* Switch to 4-bit mode, 1 line, small fonts */
-		lcd->ops->write_cmd_raw4(lcd, LCD_CMD_FUNCTION_SET >> 4);
+		hdc->write_cmd_raw4(hdc, LCD_CMD_FUNCTION_SET >> 4);
 		long_sleep(10);
 	}
 
 	/* set font height and lines number */
-	lcd->ops->write_cmd(lcd,
+	hdc->write_cmd(hdc,
 		LCD_CMD_FUNCTION_SET |
 		((hdc->ifwidth == 8) ? LCD_CMD_DATA_LEN_8BITS : 0) |
 		((priv->flags & LCD_FLAG_F) ? LCD_CMD_FONT_5X10_DOTS : 0) |
@@ -267,10 +268,10 @@ static int charlcd_init_display(struct charlcd *lcd)
 	long_sleep(10);
 
 	/* display off, cursor off, blink off */
-	lcd->ops->write_cmd(lcd, LCD_CMD_DISPLAY_CTRL);
+	hdc->write_cmd(hdc, LCD_CMD_DISPLAY_CTRL);
 	long_sleep(10);
 
-	lcd->ops->write_cmd(lcd,
+	hdc->write_cmd(hdc,
 		LCD_CMD_DISPLAY_CTRL |	/* set display mode */
 		((priv->flags & LCD_FLAG_D) ? LCD_CMD_DISPLAY_ON : 0) |
 		((priv->flags & LCD_FLAG_C) ? LCD_CMD_CURSOR_ON : 0) |
@@ -281,7 +282,7 @@ static int charlcd_init_display(struct charlcd *lcd)
 	long_sleep(10);
 
 	/* entry mode set : increment, cursor shifting */
-	lcd->ops->write_cmd(lcd, LCD_CMD_ENTRY_MODE | LCD_CMD_CURSOR_INC);
+	hdc->write_cmd(hdc, LCD_CMD_ENTRY_MODE | LCD_CMD_CURSOR_INC);
 
 	charlcd_clear_display(lcd);
 	return 0;
@@ -417,7 +418,7 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 		if (priv->addr.x > 0) {
 			/* back one char if not at end of line */
 			if (priv->addr.x < hdc->bwidth)
-				lcd->ops->write_cmd(lcd, LCD_CMD_SHIFT);
+				hdc->write_cmd(hdc, LCD_CMD_SHIFT);
 			priv->addr.x--;
 		}
 		processed = 1;
@@ -426,18 +427,18 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 		if (priv->addr.x < lcd->width) {
 			/* allow the cursor to pass the end of the line */
 			if (priv->addr.x < (hdc->bwidth - 1))
-				lcd->ops->write_cmd(lcd,
+				hdc->write_cmd(hdc,
 					LCD_CMD_SHIFT | LCD_CMD_SHIFT_RIGHT);
 			priv->addr.x++;
 		}
 		processed = 1;
 		break;
 	case 'L':	/* shift display left */
-		lcd->ops->write_cmd(lcd, LCD_CMD_SHIFT | LCD_CMD_DISPLAY_SHIFT);
+		hdc->write_cmd(hdc, LCD_CMD_SHIFT | LCD_CMD_DISPLAY_SHIFT);
 		processed = 1;
 		break;
 	case 'R':	/* shift display right */
-		lcd->ops->write_cmd(lcd,
+		hdc->write_cmd(hdc,
 				    LCD_CMD_SHIFT | LCD_CMD_DISPLAY_SHIFT |
 				    LCD_CMD_SHIFT_RIGHT);
 		processed = 1;
@@ -503,7 +504,7 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 			}
 		}
 
-		lcd->ops->write_cmd(lcd, LCD_CMD_SET_CGRAM_ADDR | (cgaddr * 8));
+		hdc->write_cmd(hdc, LCD_CMD_SET_CGRAM_ADDR | (cgaddr * 8));
 		for (addr = 0; addr < cgoffset; addr++)
 			hdc->write_data(hdc, cgbytes[addr]);
 
@@ -535,14 +536,14 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 	if ((oldflags ^ priv->flags) &
 	    (LCD_FLAG_B | LCD_FLAG_C | LCD_FLAG_D))
 		/* set display mode */
-		lcd->ops->write_cmd(lcd,
+		hdc->write_cmd(hdc,
 			LCD_CMD_DISPLAY_CTRL |
 			((priv->flags & LCD_FLAG_D) ? LCD_CMD_DISPLAY_ON : 0) |
 			((priv->flags & LCD_FLAG_C) ? LCD_CMD_CURSOR_ON : 0) |
 			((priv->flags & LCD_FLAG_B) ? LCD_CMD_BLINK_ON : 0));
 	/* check whether one of F,N flags was changed */
 	else if ((oldflags ^ priv->flags) & (LCD_FLAG_F | LCD_FLAG_N))
-		lcd->ops->write_cmd(lcd,
+		hdc->write_cmd(hdc,
 			LCD_CMD_FUNCTION_SET |
 			((hdc->ifwidth == 8) ? LCD_CMD_DATA_LEN_8BITS : 0) |
 			((priv->flags & LCD_FLAG_F) ? LCD_CMD_FONT_5X10_DOTS : 0) |
@@ -583,13 +584,13 @@ static void charlcd_write_char(struct charlcd *lcd, char c)
 				 */
 				if (priv->addr.x < hdc->bwidth)
 					/* back one char */
-					lcd->ops->write_cmd(lcd, LCD_CMD_SHIFT);
+					hdc->write_cmd(hdc, LCD_CMD_SHIFT);
 				priv->addr.x--;
 			}
 			/* replace with a space */
 			hdc->write_data(hdc, ' ');
 			/* back one char again */
-			lcd->ops->write_cmd(lcd, LCD_CMD_SHIFT);
+			hdc->write_cmd(hdc, LCD_CMD_SHIFT);
 			break;
 		case '\f':
 			/* quickly clear the display */
diff --git a/drivers/auxdisplay/charlcd.h b/drivers/auxdisplay/charlcd.h
index fba4f2cd42c4..ad6fd2733523 100644
--- a/drivers/auxdisplay/charlcd.h
+++ b/drivers/auxdisplay/charlcd.h
@@ -25,11 +25,6 @@ struct charlcd {
 };
 
 struct charlcd_ops {
-	/* Required */
-	void (*write_cmd)(struct charlcd *lcd, int cmd);
-
-	/* Optional */
-	void (*write_cmd_raw4)(struct charlcd *lcd, int cmd);	/* 4-bit only */
 	void (*clear_fast)(struct charlcd *lcd);
 	void (*backlight)(struct charlcd *lcd, enum charlcd_onoff on);
 };
diff --git a/drivers/auxdisplay/hd44780.c b/drivers/auxdisplay/hd44780.c
index 922f0e0d2e6d..dc4738563298 100644
--- a/drivers/auxdisplay/hd44780.c
+++ b/drivers/auxdisplay/hd44780.c
@@ -103,9 +103,8 @@ static void hd44780_write_gpio4(struct hd44780 *hd, u8 val, unsigned int rs)
 }
 
 /* Send a command to the LCD panel in 8 bit GPIO mode */
-static void hd44780_write_cmd_gpio8(struct charlcd *lcd, int cmd)
+static void hd44780_write_cmd_gpio8(struct hd44780_common *hdc, int cmd)
 {
-	struct hd44780_common *hdc = lcd->drvdata;
 	struct hd44780 *hd = hdc->hd44780;
 
 	hd44780_write_gpio8(hd, cmd, 0);
@@ -126,14 +125,12 @@ static void hd44780_write_data_gpio8(struct hd44780_common *hdc, int data)
 }
 
 static const struct charlcd_ops hd44780_ops_gpio8 = {
-	.write_cmd	= hd44780_write_cmd_gpio8,
 	.backlight	= hd44780_backlight,
 };
 
 /* Send a command to the LCD panel in 4 bit GPIO mode */
-static void hd44780_write_cmd_gpio4(struct charlcd *lcd, int cmd)
+static void hd44780_write_cmd_gpio4(struct hd44780_common *hdc, int cmd)
 {
-	struct hd44780_common *hdc = lcd->drvdata;
 	struct hd44780 *hd = hdc->hd44780;
 
 	hd44780_write_gpio4(hd, cmd, 0);
@@ -143,10 +140,9 @@ static void hd44780_write_cmd_gpio4(struct charlcd *lcd, int cmd)
 }
 
 /* Send 4-bits of a command to the LCD panel in raw 4 bit GPIO mode */
-static void hd44780_write_cmd_raw_gpio4(struct charlcd *lcd, int cmd)
+static void hd44780_write_cmd_raw_gpio4(struct hd44780_common *hdc, int cmd)
 {
 	DECLARE_BITMAP(values, 6); /* for DATA[4-7], RS, RW */
-	struct hd44780_common *hdc = lcd->drvdata;
 	struct hd44780 *hd = hdc->hd44780;
 	unsigned int n;
 
@@ -172,8 +168,6 @@ static void hd44780_write_data_gpio4(struct hd44780_common *hdc, int data)
 }
 
 static const struct charlcd_ops hd44780_ops_gpio4 = {
-	.write_cmd	= hd44780_write_cmd_gpio4,
-	.write_cmd_raw4	= hd44780_write_cmd_raw_gpio4,
 	.backlight	= hd44780_backlight,
 };
 
@@ -275,9 +269,12 @@ static int hd44780_probe(struct platform_device *pdev)
 	if (ifwidth == 8) {
 		lcd->ops = &hd44780_ops_gpio8;
 		hdc->write_data = hd44780_write_data_gpio8;
+		hdc->write_cmd = hd44780_write_cmd_gpio8;
 	} else {
 		lcd->ops = &hd44780_ops_gpio4;
 		hdc->write_data = hd44780_write_data_gpio4;
+		hdc->write_cmd = hd44780_write_cmd_gpio4;
+		hdc->write_cmd_raw4 = hd44780_write_cmd_raw_gpio4;
 	}
 
 	ret = charlcd_register(lcd);
diff --git a/drivers/auxdisplay/hd44780_common.h b/drivers/auxdisplay/hd44780_common.h
index bcc13421bf45..73dd4c7c6de3 100644
--- a/drivers/auxdisplay/hd44780_common.h
+++ b/drivers/auxdisplay/hd44780_common.h
@@ -8,6 +8,9 @@ struct hd44780_common {
 	int bwidth;			/* Default set by hd44780_alloc() */
 	int hwidth;			/* Default set by hd44780_alloc() */
 	void (*write_data)(struct hd44780_common *hdc, int data);
+	void (*write_cmd)(struct hd44780_common *hdc, int cmd);
+	/* write_cmd_raw4 is for 4-bit connected displays only */
+	void (*write_cmd_raw4)(struct hd44780_common *hdc, int cmd);
 	void *hd44780;
 };
 
diff --git a/drivers/auxdisplay/panel.c b/drivers/auxdisplay/panel.c
index 15100d21a6e9..7ef9bc7188ca 100644
--- a/drivers/auxdisplay/panel.c
+++ b/drivers/auxdisplay/panel.c
@@ -723,7 +723,7 @@ static void lcd_backlight(struct charlcd *charlcd, enum charlcd_onoff on)
 }
 
 /* send a command to the LCD panel in serial mode */
-static void lcd_write_cmd_s(struct charlcd *charlcd, int cmd)
+static void lcd_write_cmd_s(struct hd44780_common *hdc, int cmd)
 {
 	spin_lock_irq(&pprt_lock);
 	lcd_send_serial(0x1F);	/* R/W=W, RS=0 */
@@ -745,7 +745,7 @@ static void lcd_write_data_s(struct hd44780_common *hdc, int data)
 }
 
 /* send a command to the LCD panel in 8 bits parallel mode */
-static void lcd_write_cmd_p8(struct charlcd *charlcd, int cmd)
+static void lcd_write_cmd_p8(struct hd44780_common *hdc, int cmd)
 {
 	spin_lock_irq(&pprt_lock);
 	/* present the data to the data port */
@@ -789,7 +789,7 @@ static void lcd_write_data_p8(struct hd44780_common *hdc, int data)
 }
 
 /* send a command to the TI LCD panel */
-static void lcd_write_cmd_tilcd(struct charlcd *charlcd, int cmd)
+static void lcd_write_cmd_tilcd(struct hd44780_common *hdc, int cmd)
 {
 	spin_lock_irq(&pprt_lock);
 	/* present the data to the control port */
@@ -873,19 +873,16 @@ static void lcd_clear_fast_tilcd(struct charlcd *charlcd)
 }
 
 static const struct charlcd_ops charlcd_serial_ops = {
-	.write_cmd	= lcd_write_cmd_s,
 	.clear_fast	= lcd_clear_fast_s,
 	.backlight	= lcd_backlight,
 };
 
 static const struct charlcd_ops charlcd_parallel_ops = {
-	.write_cmd	= lcd_write_cmd_p8,
 	.clear_fast	= lcd_clear_fast_p8,
 	.backlight	= lcd_backlight,
 };
 
 static const struct charlcd_ops charlcd_tilcd_ops = {
-	.write_cmd	= lcd_write_cmd_tilcd,
 	.clear_fast	= lcd_clear_fast_tilcd,
 	.backlight	= lcd_backlight,
 };
@@ -1017,6 +1014,7 @@ static void lcd_init(void)
 	if (lcd.proto == LCD_PROTO_SERIAL) {	/* SERIAL */
 		charlcd->ops = &charlcd_serial_ops;
 		hdc->write_data = lcd_write_data_s;
+		hdc->write_cmd = lcd_write_cmd_s;
 
 		if (lcd.pins.cl == PIN_NOT_SET)
 			lcd.pins.cl = DEFAULT_LCD_PIN_SCL;
@@ -1026,6 +1024,7 @@ static void lcd_init(void)
 	} else if (lcd.proto == LCD_PROTO_PARALLEL) {	/* PARALLEL */
 		charlcd->ops = &charlcd_parallel_ops;
 		hdc->write_data = lcd_write_data_p8;
+		hdc->write_cmd = lcd_write_cmd_p8;
 
 		if (lcd.pins.e == PIN_NOT_SET)
 			lcd.pins.e = DEFAULT_LCD_PIN_E;
@@ -1036,6 +1035,7 @@ static void lcd_init(void)
 	} else {
 		charlcd->ops = &charlcd_tilcd_ops;
 		hdc->write_data = lcd_write_data_tilcd;
+		hdc->write_cmd = lcd_write_cmd_tilcd;
 	}
 
 	if (lcd.pins.bl == PIN_NOT_SET)
-- 
2.28.0

[PATCH v5 07/25] auxdisplay: Move addr out of charlcd_priv

[poeschel]

From: Lars Poeschel <poeschel@lemonage.de>

Move out the struct addr from struct charlcd_priv into the less private
struct charlcd. This member is used to pass position information. The
individual drivers need to be able to read this information, so we move
this out of charlcd_priv to charlcd structure.

Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
 drivers/auxdisplay/charlcd.c | 61 +++++++++++++++---------------------
 drivers/auxdisplay/charlcd.h |  6 ++++
 2 files changed, 31 insertions(+), 36 deletions(-)

diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index ce6622f71c34..1b37d4bc38f9 100644
--- a/drivers/auxdisplay/charlcd.c
+++ b/drivers/auxdisplay/charlcd.c
@@ -72,12 +72,6 @@ struct charlcd_priv {
 	/* contains the LCD config state */
 	unsigned long int flags;
 
-	/* Contains the LCD X and Y offset */
-	struct {
-		unsigned long int x;
-		unsigned long int y;
-	} addr;
-
 	/* Current escape sequence and it's length or -1 if outside */
 	struct {
 		char buf[LCD_ESCAPE_LEN + 1];
@@ -148,7 +142,6 @@ EXPORT_SYMBOL_GPL(charlcd_poke);
 
 static void charlcd_gotoxy(struct charlcd *lcd)
 {
-	struct charlcd_priv *priv = charlcd_to_priv(lcd);
 	struct hd44780_common *hdc = lcd->drvdata;
 	unsigned int addr;
 
@@ -156,37 +149,34 @@ static void charlcd_gotoxy(struct charlcd *lcd)
 	 * we force the cursor to stay at the end of the
 	 * line if it wants to go farther
 	 */
-	addr = priv->addr.x < hdc->bwidth ? priv->addr.x & (hdc->hwidth - 1)
+	addr = lcd->addr.x < hdc->bwidth ? lcd->addr.x & (hdc->hwidth - 1)
 					  : hdc->bwidth - 1;
-	if (priv->addr.y & 1)
+	if (lcd->addr.y & 1)
 		addr += hdc->hwidth;
-	if (priv->addr.y & 2)
+	if (lcd->addr.y & 2)
 		addr += hdc->bwidth;
 	hdc->write_cmd(hdc, LCD_CMD_SET_DDRAM_ADDR | addr);
 }
 
 static void charlcd_home(struct charlcd *lcd)
 {
-	struct charlcd_priv *priv = charlcd_to_priv(lcd);
-
-	priv->addr.x = 0;
-	priv->addr.y = 0;
+	lcd->addr.x = 0;
+	lcd->addr.y = 0;
 	charlcd_gotoxy(lcd);
 }
 
 static void charlcd_print(struct charlcd *lcd, char c)
 {
-	struct charlcd_priv *priv = charlcd_to_priv(lcd);
 	struct hd44780_common *hdc = lcd->drvdata;
 
-	if (priv->addr.x < hdc->bwidth) {
+	if (lcd->addr.x < hdc->bwidth) {
 		if (lcd->char_conv)
 			c = lcd->char_conv[(unsigned char)c];
 		hdc->write_data(hdc, c);
-		priv->addr.x++;
+		lcd->addr.x++;
 
 		/* prevents the cursor from wrapping onto the next line */
-		if (priv->addr.x == hdc->bwidth)
+		if (lcd->addr.x == hdc->bwidth)
 			charlcd_gotoxy(lcd);
 	}
 }
@@ -210,12 +200,11 @@ static void charlcd_clear_fast(struct charlcd *lcd)
 /* clears the display and resets X/Y */
 static void charlcd_clear_display(struct charlcd *lcd)
 {
-	struct charlcd_priv *priv = charlcd_to_priv(lcd);
 	struct hd44780_common *hdc = lcd->drvdata;
 
 	hdc->write_cmd(hdc, LCD_CMD_DISPLAY_CLEAR);
-	priv->addr.x = 0;
-	priv->addr.y = 0;
+	lcd->addr.x = 0;
+	lcd->addr.y = 0;
 	/* we must wait a few milliseconds (15) */
 	long_sleep(15);
 }
@@ -415,21 +404,21 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 		processed = 1;
 		break;
 	case 'l':	/* Shift Cursor Left */
-		if (priv->addr.x > 0) {
+		if (lcd->addr.x > 0) {
 			/* back one char if not at end of line */
-			if (priv->addr.x < hdc->bwidth)
+			if (lcd->addr.x < hdc->bwidth)
 				hdc->write_cmd(hdc, LCD_CMD_SHIFT);
-			priv->addr.x--;
+			lcd->addr.x--;
 		}
 		processed = 1;
 		break;
 	case 'r':	/* shift cursor right */
-		if (priv->addr.x < lcd->width) {
+		if (lcd->addr.x < lcd->width) {
 			/* allow the cursor to pass the end of the line */
-			if (priv->addr.x < (hdc->bwidth - 1))
+			if (lcd->addr.x < (hdc->bwidth - 1))
 				hdc->write_cmd(hdc,
 					LCD_CMD_SHIFT | LCD_CMD_SHIFT_RIGHT);
-			priv->addr.x++;
+			lcd->addr.x++;
 		}
 		processed = 1;
 		break;
@@ -446,7 +435,7 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 	case 'k': {	/* kill end of line */
 		int x;
 
-		for (x = priv->addr.x; x < hdc->bwidth; x++)
+		for (x = lcd->addr.x; x < hdc->bwidth; x++)
 			hdc->write_data(hdc, ' ');
 
 		/* restore cursor position */
@@ -519,7 +508,7 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 			break;
 
 		/* If the command is valid, move to the new address */
-		if (parse_xy(esc, &priv->addr.x, &priv->addr.y))
+		if (parse_xy(esc, &lcd->addr.x, &lcd->addr.y))
 			charlcd_gotoxy(lcd);
 
 		/* Regardless of its validity, mark as processed */
@@ -577,15 +566,15 @@ static void charlcd_write_char(struct charlcd *lcd, char c)
 			break;
 		case '\b':
 			/* go back one char and clear it */
-			if (priv->addr.x > 0) {
+			if (lcd->addr.x > 0) {
 				/*
 				 * check if we're not at the
 				 * end of the line
 				 */
-				if (priv->addr.x < hdc->bwidth)
+				if (lcd->addr.x < hdc->bwidth)
 					/* back one char */
 					hdc->write_cmd(hdc, LCD_CMD_SHIFT);
-				priv->addr.x--;
+				lcd->addr.x--;
 			}
 			/* replace with a space */
 			hdc->write_data(hdc, ' ');
@@ -601,15 +590,15 @@ static void charlcd_write_char(struct charlcd *lcd, char c)
 			 * flush the remainder of the current line and
 			 * go to the beginning of the next line
 			 */
-			for (; priv->addr.x < hdc->bwidth; priv->addr.x++)
+			for (; lcd->addr.x < hdc->bwidth; lcd->addr.x++)
 				hdc->write_data(hdc, ' ');
-			priv->addr.x = 0;
-			priv->addr.y = (priv->addr.y + 1) % lcd->height;
+			lcd->addr.x = 0;
+			lcd->addr.y = (lcd->addr.y + 1) % lcd->height;
 			charlcd_gotoxy(lcd);
 			break;
 		case '\r':
 			/* go to the beginning of the same line */
-			priv->addr.x = 0;
+			lcd->addr.x = 0;
 			charlcd_gotoxy(lcd);
 			break;
 		case '\t':
diff --git a/drivers/auxdisplay/charlcd.h b/drivers/auxdisplay/charlcd.h
index ad6fd2733523..ff4896af2189 100644
--- a/drivers/auxdisplay/charlcd.h
+++ b/drivers/auxdisplay/charlcd.h
@@ -21,6 +21,12 @@ struct charlcd {
 	int height;
 	int width;
 
+	/* Contains the LCD X and Y offset */
+	struct {
+		unsigned long x;
+		unsigned long y;
+	} addr;
+
 	void *drvdata;
 };
 
-- 
2.28.0

[PATCH v5 08/25] auxdisplay: hd44780_common_print

[poeschel]

From: Lars Poeschel <poeschel@lemonage.de>

We create a hd44780_common_print function. It is derived from the
original charlcd_print. charlcd_print becomes a device independent print
function, that then only calls via its ops function pointers, into the
print function offered by drivers.

Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
Changes in v5:
- Fix some typos

Changes in v3:
- Fix kernel test robot reported error: Missed EXPORT_SYMBOL_GPL
---
 drivers/auxdisplay/charlcd.c        | 28 +++++++++++++++-------------
 drivers/auxdisplay/charlcd.h        | 12 ++++++++++++
 drivers/auxdisplay/hd44780.c        |  2 ++
 drivers/auxdisplay/hd44780_common.c | 14 ++++++++++++++
 drivers/auxdisplay/hd44780_common.h |  1 +
 5 files changed, 44 insertions(+), 13 deletions(-)

diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index 1b37d4bc38f9..72ed004a8980 100644
--- a/drivers/auxdisplay/charlcd.c
+++ b/drivers/auxdisplay/charlcd.c
@@ -167,18 +167,15 @@ static void charlcd_home(struct charlcd *lcd)
 
 static void charlcd_print(struct charlcd *lcd, char c)
 {
-	struct hd44780_common *hdc = lcd->drvdata;
+	if (lcd->char_conv)
+		c = lcd->char_conv[(unsigned char)c];
 
-	if (lcd->addr.x < hdc->bwidth) {
-		if (lcd->char_conv)
-			c = lcd->char_conv[(unsigned char)c];
-		hdc->write_data(hdc, c);
+	if (!lcd->ops->print(lcd, c))
 		lcd->addr.x++;
 
-		/* prevents the cursor from wrapping onto the next line */
-		if (lcd->addr.x == hdc->bwidth)
-			charlcd_gotoxy(lcd);
-	}
+	/* prevents the cursor from wrapping onto the next line */
+	if (lcd->addr.x == lcd->width)
+		charlcd_gotoxy(lcd);
 }
 
 static void charlcd_clear_fast(struct charlcd *lcd)
@@ -192,7 +189,7 @@ static void charlcd_clear_fast(struct charlcd *lcd)
 		lcd->ops->clear_fast(lcd);
 	else
 		for (pos = 0; pos < min(2, lcd->height) * hdc->hwidth; pos++)
-			hdc->write_data(hdc, ' ');
+			lcd->ops->print(lcd, ' ');
 
 	charlcd_home(lcd);
 }
@@ -433,12 +430,16 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 		processed = 1;
 		break;
 	case 'k': {	/* kill end of line */
-		int x;
+		int x, xs, ys;
 
+		xs = lcd->addr.x;
+		ys = lcd->addr.y;
 		for (x = lcd->addr.x; x < hdc->bwidth; x++)
-			hdc->write_data(hdc, ' ');
+			lcd->ops->print(lcd, ' ');
 
 		/* restore cursor position */
+		lcd->addr.x = xs;
+		lcd->addr.y = ys;
 		charlcd_gotoxy(lcd);
 		processed = 1;
 		break;
@@ -591,7 +592,8 @@ static void charlcd_write_char(struct charlcd *lcd, char c)
 			 * go to the beginning of the next line
 			 */
 			for (; lcd->addr.x < hdc->bwidth; lcd->addr.x++)
-				hdc->write_data(hdc, ' ');
+				lcd->ops->print(lcd, ' ');
+
 			lcd->addr.x = 0;
 			lcd->addr.y = (lcd->addr.y + 1) % lcd->height;
 			charlcd_gotoxy(lcd);
diff --git a/drivers/auxdisplay/charlcd.h b/drivers/auxdisplay/charlcd.h
index ff4896af2189..94922e3c1c4c 100644
--- a/drivers/auxdisplay/charlcd.h
+++ b/drivers/auxdisplay/charlcd.h
@@ -30,9 +30,21 @@ struct charlcd {
 	void *drvdata;
 };
 
+/**
+ * struct charlcd_ops - Functions used by charlcd. Drivers have to implement
+ * these.
+ * @clear_fast: Clear the whole display and set cursor to position 0, 0.
+ * Optional.
+ * @backlight: Turn backlight on or off. Optional.
+ * @print: Print one character to the display at current cursor position.
+ * The cursor is advanced by charlcd.
+ * The buffered cursor position is advanced by charlcd. The cursor should not
+ * wrap to the next line at the end of a line.
+ */
 struct charlcd_ops {
 	void (*clear_fast)(struct charlcd *lcd);
 	void (*backlight)(struct charlcd *lcd, enum charlcd_onoff on);
+	int (*print)(struct charlcd *lcd, int c);
 };
 
 struct charlcd *charlcd_alloc(void);
diff --git a/drivers/auxdisplay/hd44780.c b/drivers/auxdisplay/hd44780.c
index dc4738563298..9680bb611639 100644
--- a/drivers/auxdisplay/hd44780.c
+++ b/drivers/auxdisplay/hd44780.c
@@ -126,6 +126,7 @@ static void hd44780_write_data_gpio8(struct hd44780_common *hdc, int data)
 
 static const struct charlcd_ops hd44780_ops_gpio8 = {
 	.backlight	= hd44780_backlight,
+	.print		= hd44780_common_print,
 };
 
 /* Send a command to the LCD panel in 4 bit GPIO mode */
@@ -169,6 +170,7 @@ static void hd44780_write_data_gpio4(struct hd44780_common *hdc, int data)
 
 static const struct charlcd_ops hd44780_ops_gpio4 = {
 	.backlight	= hd44780_backlight,
+	.print		= hd44780_common_print,
 };
 
 static int hd44780_probe(struct platform_device *pdev)
diff --git a/drivers/auxdisplay/hd44780_common.c b/drivers/auxdisplay/hd44780_common.c
index 4968461f0c4a..1dfcb2cdbc70 100644
--- a/drivers/auxdisplay/hd44780_common.c
+++ b/drivers/auxdisplay/hd44780_common.c
@@ -2,8 +2,22 @@
 #include <linux/module.h>
 #include <linux/slab.h>
 
+#include "charlcd.h"
 #include "hd44780_common.h"
 
+int hd44780_common_print(struct charlcd *lcd, int c)
+{
+	struct hd44780_common *hdc = lcd->drvdata;
+
+	if (lcd->addr.x < hdc->bwidth) {
+		hdc->write_data(hdc, c);
+		return 0;
+	}
+
+	return 1;
+}
+EXPORT_SYMBOL_GPL(hd44780_common_print);
+
 struct hd44780_common *hd44780_common_alloc(void)
 {
 	struct hd44780_common *hd;
diff --git a/drivers/auxdisplay/hd44780_common.h b/drivers/auxdisplay/hd44780_common.h
index 73dd4c7c6de3..ac404a44889b 100644
--- a/drivers/auxdisplay/hd44780_common.h
+++ b/drivers/auxdisplay/hd44780_common.h
@@ -14,4 +14,5 @@ struct hd44780_common {
 	void *hd44780;
 };
 
+int hd44780_common_print(struct charlcd *lcd, int c);
 struct hd44780_common *hd44780_common_alloc(void);
-- 
2.28.0

[PATCH v5 09/25] auxdisplay: provide hd44780_common_gotoxy

[poeschel]

From: Lars Poeschel <poeschel@lemonage.de>

Provide a hd44780_common_gotoxy function and a pointer in the ops for
charlcd to use to move the cursor.

Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
 drivers/auxdisplay/charlcd.c        | 38 +++++++++--------------------
 drivers/auxdisplay/charlcd.h        |  4 ++-
 drivers/auxdisplay/hd44780.c        |  2 ++
 drivers/auxdisplay/hd44780_common.c | 23 +++++++++++++++++
 drivers/auxdisplay/hd44780_common.h |  1 +
 drivers/auxdisplay/panel.c          |  3 +++
 6 files changed, 43 insertions(+), 28 deletions(-)

diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index 72ed004a8980..d6f971eea6ae 100644
--- a/drivers/auxdisplay/charlcd.c
+++ b/drivers/auxdisplay/charlcd.c
@@ -55,7 +55,7 @@
 
 #define LCD_CMD_SET_CGRAM_ADDR	0x40	/* Set char generator RAM address */
 
-#define LCD_CMD_SET_DDRAM_ADDR	0x80	/* Set display data RAM address */
+#define LCD_CMD_SET_DDRAM_ADDR 0x80    /* Set display data RAM address */
 
 #define LCD_ESCAPE_LEN		24	/* Max chars for LCD escape command */
 #define LCD_ESCAPE_CHAR		27	/* Use char 27 for escape command */
@@ -140,33 +140,17 @@ void charlcd_poke(struct charlcd *lcd)
 }
 EXPORT_SYMBOL_GPL(charlcd_poke);
 
-static void charlcd_gotoxy(struct charlcd *lcd)
-{
-	struct hd44780_common *hdc = lcd->drvdata;
-	unsigned int addr;
-
-	/*
-	 * we force the cursor to stay at the end of the
-	 * line if it wants to go farther
-	 */
-	addr = lcd->addr.x < hdc->bwidth ? lcd->addr.x & (hdc->hwidth - 1)
-					  : hdc->bwidth - 1;
-	if (lcd->addr.y & 1)
-		addr += hdc->hwidth;
-	if (lcd->addr.y & 2)
-		addr += hdc->bwidth;
-	hdc->write_cmd(hdc, LCD_CMD_SET_DDRAM_ADDR | addr);
-}
-
 static void charlcd_home(struct charlcd *lcd)
 {
 	lcd->addr.x = 0;
 	lcd->addr.y = 0;
-	charlcd_gotoxy(lcd);
+	lcd->ops->gotoxy(lcd);
 }
 
 static void charlcd_print(struct charlcd *lcd, char c)
 {
+	struct hd44780_common *hdc = lcd->drvdata;
+
 	if (lcd->char_conv)
 		c = lcd->char_conv[(unsigned char)c];
 
@@ -174,8 +158,8 @@ static void charlcd_print(struct charlcd *lcd, char c)
 		lcd->addr.x++;
 
 	/* prevents the cursor from wrapping onto the next line */
-	if (lcd->addr.x == lcd->width)
-		charlcd_gotoxy(lcd);
+	if (lcd->addr.x == hdc->bwidth)
+		lcd->ops->gotoxy(lcd);
 }
 
 static void charlcd_clear_fast(struct charlcd *lcd)
@@ -440,7 +424,7 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 		/* restore cursor position */
 		lcd->addr.x = xs;
 		lcd->addr.y = ys;
-		charlcd_gotoxy(lcd);
+		lcd->ops->gotoxy(lcd);
 		processed = 1;
 		break;
 	}
@@ -499,7 +483,7 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 			hdc->write_data(hdc, cgbytes[addr]);
 
 		/* ensures that we stop writing to CGRAM */
-		charlcd_gotoxy(lcd);
+		lcd->ops->gotoxy(lcd);
 		processed = 1;
 		break;
 	}
@@ -510,7 +494,7 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 
 		/* If the command is valid, move to the new address */
 		if (parse_xy(esc, &lcd->addr.x, &lcd->addr.y))
-			charlcd_gotoxy(lcd);
+			lcd->ops->gotoxy(lcd);
 
 		/* Regardless of its validity, mark as processed */
 		processed = 1;
@@ -596,12 +580,12 @@ static void charlcd_write_char(struct charlcd *lcd, char c)
 
 			lcd->addr.x = 0;
 			lcd->addr.y = (lcd->addr.y + 1) % lcd->height;
-			charlcd_gotoxy(lcd);
+			lcd->ops->gotoxy(lcd);
 			break;
 		case '\r':
 			/* go to the beginning of the same line */
 			lcd->addr.x = 0;
-			charlcd_gotoxy(lcd);
+			lcd->ops->gotoxy(lcd);
 			break;
 		case '\t':
 			/* print a space instead of the tab */
diff --git a/drivers/auxdisplay/charlcd.h b/drivers/auxdisplay/charlcd.h
index 94922e3c1c4c..f36cc80ce385 100644
--- a/drivers/auxdisplay/charlcd.h
+++ b/drivers/auxdisplay/charlcd.h
@@ -37,14 +37,16 @@ struct charlcd {
  * Optional.
  * @backlight: Turn backlight on or off. Optional.
  * @print: Print one character to the display at current cursor position.
- * The cursor is advanced by charlcd.
  * The buffered cursor position is advanced by charlcd. The cursor should not
  * wrap to the next line at the end of a line.
+ * @gotoxy: Set cursor to x, y. The x and y values to set the cursor to are
+ * previously set in addr.x and addr.y by charlcd.
  */
 struct charlcd_ops {
 	void (*clear_fast)(struct charlcd *lcd);
 	void (*backlight)(struct charlcd *lcd, enum charlcd_onoff on);
 	int (*print)(struct charlcd *lcd, int c);
+	int (*gotoxy)(struct charlcd *lcd);
 };
 
 struct charlcd *charlcd_alloc(void);
diff --git a/drivers/auxdisplay/hd44780.c b/drivers/auxdisplay/hd44780.c
index 9680bb611639..4d9478f6e5ff 100644
--- a/drivers/auxdisplay/hd44780.c
+++ b/drivers/auxdisplay/hd44780.c
@@ -127,6 +127,7 @@ static void hd44780_write_data_gpio8(struct hd44780_common *hdc, int data)
 static const struct charlcd_ops hd44780_ops_gpio8 = {
 	.backlight	= hd44780_backlight,
 	.print		= hd44780_common_print,
+	.gotoxy		= hd44780_common_gotoxy,
 };
 
 /* Send a command to the LCD panel in 4 bit GPIO mode */
@@ -171,6 +172,7 @@ static void hd44780_write_data_gpio4(struct hd44780_common *hdc, int data)
 static const struct charlcd_ops hd44780_ops_gpio4 = {
 	.backlight	= hd44780_backlight,
 	.print		= hd44780_common_print,
+	.gotoxy		= hd44780_common_gotoxy,
 };
 
 static int hd44780_probe(struct platform_device *pdev)
diff --git a/drivers/auxdisplay/hd44780_common.c b/drivers/auxdisplay/hd44780_common.c
index 1dfcb2cdbc70..f86eb2f27cee 100644
--- a/drivers/auxdisplay/hd44780_common.c
+++ b/drivers/auxdisplay/hd44780_common.c
@@ -5,6 +5,9 @@
 #include "charlcd.h"
 #include "hd44780_common.h"
 
+/* LCD commands */
+#define LCD_CMD_SET_DDRAM_ADDR	0x80	/* Set display data RAM address */
+
 int hd44780_common_print(struct charlcd *lcd, int c)
 {
 	struct hd44780_common *hdc = lcd->drvdata;
@@ -18,6 +21,26 @@ int hd44780_common_print(struct charlcd *lcd, int c)
 }
 EXPORT_SYMBOL_GPL(hd44780_common_print);
 
+int hd44780_common_gotoxy(struct charlcd *lcd)
+{
+	struct hd44780_common *hdc = lcd->drvdata;
+	unsigned int addr;
+
+	/*
+	 * we force the cursor to stay at the end of the
+	 * line if it wants to go farther
+	 */
+	addr = lcd->addr.x < hdc->bwidth ? lcd->addr.x & (hdc->hwidth - 1)
+					  : hdc->bwidth - 1;
+	if (lcd->addr.y & 1)
+		addr += hdc->hwidth;
+	if (lcd->addr.y & 2)
+		addr += hdc->bwidth;
+	hdc->write_cmd(hdc, LCD_CMD_SET_DDRAM_ADDR | addr);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(hd44780_common_gotoxy);
+
 struct hd44780_common *hd44780_common_alloc(void)
 {
 	struct hd44780_common *hd;
diff --git a/drivers/auxdisplay/hd44780_common.h b/drivers/auxdisplay/hd44780_common.h
index ac404a44889b..d8cbea4a8658 100644
--- a/drivers/auxdisplay/hd44780_common.h
+++ b/drivers/auxdisplay/hd44780_common.h
@@ -15,4 +15,5 @@ struct hd44780_common {
 };
 
 int hd44780_common_print(struct charlcd *lcd, int c);
+int hd44780_common_gotoxy(struct charlcd *lcd);
 struct hd44780_common *hd44780_common_alloc(void);
diff --git a/drivers/auxdisplay/panel.c b/drivers/auxdisplay/panel.c
index 7ef9bc7188ca..75894eacd12f 100644
--- a/drivers/auxdisplay/panel.c
+++ b/drivers/auxdisplay/panel.c
@@ -875,16 +875,19 @@ static void lcd_clear_fast_tilcd(struct charlcd *charlcd)
 static const struct charlcd_ops charlcd_serial_ops = {
 	.clear_fast	= lcd_clear_fast_s,
 	.backlight	= lcd_backlight,
+	.gotoxy		= hd44780_common_gotoxy,
 };
 
 static const struct charlcd_ops charlcd_parallel_ops = {
 	.clear_fast	= lcd_clear_fast_p8,
 	.backlight	= lcd_backlight,
+	.gotoxy		= hd44780_common_gotoxy,
 };
 
 static const struct charlcd_ops charlcd_tilcd_ops = {
 	.clear_fast	= lcd_clear_fast_tilcd,
 	.backlight	= lcd_backlight,
+	.gotoxy		= hd44780_common_gotoxy,
 };
 
 /* initialize the LCD driver */
-- 
2.28.0

[PATCH v5 10/25] auxdisplay: add home to charlcd_ops

[poeschel]

From: Lars Poeschel <poeschel@lemonage.de>

This adds a home function to the charlcd_ops struct and offer an
implementation for hd44780_common. This implementation is used by our
two hd44780 drivers. This is to make charlcd device independent.

Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
 drivers/auxdisplay/charlcd.c        | 2 +-
 drivers/auxdisplay/charlcd.h        | 3 +++
 drivers/auxdisplay/hd44780.c        | 2 ++
 drivers/auxdisplay/hd44780_common.c | 8 ++++++++
 drivers/auxdisplay/hd44780_common.h | 1 +
 drivers/auxdisplay/panel.c          | 3 +++
 6 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index d6f971eea6ae..44dd6e02eaf9 100644
--- a/drivers/auxdisplay/charlcd.c
+++ b/drivers/auxdisplay/charlcd.c
@@ -144,7 +144,7 @@ static void charlcd_home(struct charlcd *lcd)
 {
 	lcd->addr.x = 0;
 	lcd->addr.y = 0;
-	lcd->ops->gotoxy(lcd);
+	lcd->ops->home(lcd);
 }
 
 static void charlcd_print(struct charlcd *lcd, char c)
diff --git a/drivers/auxdisplay/charlcd.h b/drivers/auxdisplay/charlcd.h
index f36cc80ce385..236fd0e9e8ab 100644
--- a/drivers/auxdisplay/charlcd.h
+++ b/drivers/auxdisplay/charlcd.h
@@ -41,12 +41,15 @@ struct charlcd {
  * wrap to the next line at the end of a line.
  * @gotoxy: Set cursor to x, y. The x and y values to set the cursor to are
  * previously set in addr.x and addr.y by charlcd.
+ * @home: Set cursor to 0, 0. The values in addr.x and addr.y are set to 0, 0 by
+ * charlcd prior to calling this function.
  */
 struct charlcd_ops {
 	void (*clear_fast)(struct charlcd *lcd);
 	void (*backlight)(struct charlcd *lcd, enum charlcd_onoff on);
 	int (*print)(struct charlcd *lcd, int c);
 	int (*gotoxy)(struct charlcd *lcd);
+	int (*home)(struct charlcd *lcd);
 };
 
 struct charlcd *charlcd_alloc(void);
diff --git a/drivers/auxdisplay/hd44780.c b/drivers/auxdisplay/hd44780.c
index 4d9478f6e5ff..b0893ea49165 100644
--- a/drivers/auxdisplay/hd44780.c
+++ b/drivers/auxdisplay/hd44780.c
@@ -128,6 +128,7 @@ static const struct charlcd_ops hd44780_ops_gpio8 = {
 	.backlight	= hd44780_backlight,
 	.print		= hd44780_common_print,
 	.gotoxy		= hd44780_common_gotoxy,
+	.home		= hd44780_common_home,
 };
 
 /* Send a command to the LCD panel in 4 bit GPIO mode */
@@ -173,6 +174,7 @@ static const struct charlcd_ops hd44780_ops_gpio4 = {
 	.backlight	= hd44780_backlight,
 	.print		= hd44780_common_print,
 	.gotoxy		= hd44780_common_gotoxy,
+	.home		= hd44780_common_home,
 };
 
 static int hd44780_probe(struct platform_device *pdev)
diff --git a/drivers/auxdisplay/hd44780_common.c b/drivers/auxdisplay/hd44780_common.c
index f86eb2f27cee..ea62beada9d8 100644
--- a/drivers/auxdisplay/hd44780_common.c
+++ b/drivers/auxdisplay/hd44780_common.c
@@ -41,6 +41,14 @@ int hd44780_common_gotoxy(struct charlcd *lcd)
 }
 EXPORT_SYMBOL_GPL(hd44780_common_gotoxy);
 
+int hd44780_common_home(struct charlcd *lcd)
+{
+	lcd->addr.x = 0;
+	lcd->addr.y = 0;
+	return hd44780_common_gotoxy(lcd);
+}
+EXPORT_SYMBOL_GPL(hd44780_common_home);
+
 struct hd44780_common *hd44780_common_alloc(void)
 {
 	struct hd44780_common *hd;
diff --git a/drivers/auxdisplay/hd44780_common.h b/drivers/auxdisplay/hd44780_common.h
index d8cbea4a8658..c91070ed931b 100644
--- a/drivers/auxdisplay/hd44780_common.h
+++ b/drivers/auxdisplay/hd44780_common.h
@@ -16,4 +16,5 @@ struct hd44780_common {
 
 int hd44780_common_print(struct charlcd *lcd, int c);
 int hd44780_common_gotoxy(struct charlcd *lcd);
+int hd44780_common_home(struct charlcd *lcd);
 struct hd44780_common *hd44780_common_alloc(void);
diff --git a/drivers/auxdisplay/panel.c b/drivers/auxdisplay/panel.c
index 75894eacd12f..b1e874f07456 100644
--- a/drivers/auxdisplay/panel.c
+++ b/drivers/auxdisplay/panel.c
@@ -876,18 +876,21 @@ static const struct charlcd_ops charlcd_serial_ops = {
 	.clear_fast	= lcd_clear_fast_s,
 	.backlight	= lcd_backlight,
 	.gotoxy		= hd44780_common_gotoxy,
+	.home		= hd44780_common_home,
 };
 
 static const struct charlcd_ops charlcd_parallel_ops = {
 	.clear_fast	= lcd_clear_fast_p8,
 	.backlight	= lcd_backlight,
 	.gotoxy		= hd44780_common_gotoxy,
+	.home		= hd44780_common_home,
 };
 
 static const struct charlcd_ops charlcd_tilcd_ops = {
 	.clear_fast	= lcd_clear_fast_tilcd,
 	.backlight	= lcd_backlight,
 	.gotoxy		= hd44780_common_gotoxy,
+	.home		= hd44780_common_home,
 };
 
 /* initialize the LCD driver */
-- 
2.28.0

[PATCH v5 11/25] auxdisplay: Move clear_display to hd44780_common

[poeschel]

From: Lars Poeschel <poeschel@lemonage.de>

This moves the clear_display function from charlcd to hd44780_common.
This is one more step to make charlcd independent from device specific
code. The two hd44780 drivers use the new function from hd44780_common
and charlcd calls this function through its function pointer in its ops
structure.

Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
 drivers/auxdisplay/charlcd.c        | 22 ++++++----------------
 drivers/auxdisplay/charlcd.h        |  4 ++++
 drivers/auxdisplay/hd44780.c        |  2 ++
 drivers/auxdisplay/hd44780_common.c | 21 +++++++++++++++++++++
 drivers/auxdisplay/hd44780_common.h |  1 +
 drivers/auxdisplay/panel.c          |  3 +++
 6 files changed, 37 insertions(+), 16 deletions(-)

diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index 44dd6e02eaf9..fc0daf4987d5 100644
--- a/drivers/auxdisplay/charlcd.c
+++ b/drivers/auxdisplay/charlcd.c
@@ -34,8 +34,6 @@
 #define LCD_FLAG_L		0x0080	/* Backlight enabled */
 
 /* LCD commands */
-#define LCD_CMD_DISPLAY_CLEAR	0x01	/* Clear entire display */
-
 #define LCD_CMD_ENTRY_MODE	0x04	/* Set entry mode */
 #define LCD_CMD_CURSOR_INC	0x02	/* Increment cursor */
 
@@ -178,18 +176,6 @@ static void charlcd_clear_fast(struct charlcd *lcd)
 	charlcd_home(lcd);
 }
 
-/* clears the display and resets X/Y */
-static void charlcd_clear_display(struct charlcd *lcd)
-{
-	struct hd44780_common *hdc = lcd->drvdata;
-
-	hdc->write_cmd(hdc, LCD_CMD_DISPLAY_CLEAR);
-	lcd->addr.x = 0;
-	lcd->addr.y = 0;
-	/* we must wait a few milliseconds (15) */
-	long_sleep(15);
-}
-
 static int charlcd_init_display(struct charlcd *lcd)
 {
 	void (*write_cmd_raw)(struct hd44780_common *hdc, int cmd);
@@ -254,7 +240,9 @@ static int charlcd_init_display(struct charlcd *lcd)
 	/* entry mode set : increment, cursor shifting */
 	hdc->write_cmd(hdc, LCD_CMD_ENTRY_MODE | LCD_CMD_CURSOR_INC);
 
-	charlcd_clear_display(lcd);
+	lcd->ops->clear_display(lcd);
+	lcd->addr.x = 0;
+	lcd->addr.y = 0;
 	return 0;
 }
 
@@ -670,8 +658,10 @@ static int charlcd_open(struct inode *inode, struct file *file)
 		goto fail;
 
 	if (priv->must_clear) {
-		charlcd_clear_display(&priv->lcd);
+		priv->lcd.ops->clear_display(&priv->lcd);
 		priv->must_clear = false;
+		priv->lcd.addr.x = 0;
+		priv->lcd.addr.y = 0;
 	}
 	return nonseekable_open(inode, file);
 
diff --git a/drivers/auxdisplay/charlcd.h b/drivers/auxdisplay/charlcd.h
index 236fd0e9e8ab..a6c32c4d1aac 100644
--- a/drivers/auxdisplay/charlcd.h
+++ b/drivers/auxdisplay/charlcd.h
@@ -43,6 +43,9 @@ struct charlcd {
  * previously set in addr.x and addr.y by charlcd.
  * @home: Set cursor to 0, 0. The values in addr.x and addr.y are set to 0, 0 by
  * charlcd prior to calling this function.
+ * @clear_display: Again clear the whole display, set the cursor to 0, 0. The
+ * values in addr.x and addr.y are set to 0, 0 by charlcd prior to calling this
+ * function.
  */
 struct charlcd_ops {
 	void (*clear_fast)(struct charlcd *lcd);
@@ -50,6 +53,7 @@ struct charlcd_ops {
 	int (*print)(struct charlcd *lcd, int c);
 	int (*gotoxy)(struct charlcd *lcd);
 	int (*home)(struct charlcd *lcd);
+	int (*clear_display)(struct charlcd *lcd);
 };
 
 struct charlcd *charlcd_alloc(void);
diff --git a/drivers/auxdisplay/hd44780.c b/drivers/auxdisplay/hd44780.c
index b0893ea49165..40ea6d25dbe1 100644
--- a/drivers/auxdisplay/hd44780.c
+++ b/drivers/auxdisplay/hd44780.c
@@ -129,6 +129,7 @@ static const struct charlcd_ops hd44780_ops_gpio8 = {
 	.print		= hd44780_common_print,
 	.gotoxy		= hd44780_common_gotoxy,
 	.home		= hd44780_common_home,
+	.clear_display	= hd44780_common_clear_display,
 };
 
 /* Send a command to the LCD panel in 4 bit GPIO mode */
@@ -175,6 +176,7 @@ static const struct charlcd_ops hd44780_ops_gpio4 = {
 	.print		= hd44780_common_print,
 	.gotoxy		= hd44780_common_gotoxy,
 	.home		= hd44780_common_home,
+	.clear_display	= hd44780_common_clear_display,
 };
 
 static int hd44780_probe(struct platform_device *pdev)
diff --git a/drivers/auxdisplay/hd44780_common.c b/drivers/auxdisplay/hd44780_common.c
index ea62beada9d8..2f7d55668eb4 100644
--- a/drivers/auxdisplay/hd44780_common.c
+++ b/drivers/auxdisplay/hd44780_common.c
@@ -1,13 +1,22 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 #include <linux/module.h>
+#include <linux/sched.h>
 #include <linux/slab.h>
 
 #include "charlcd.h"
 #include "hd44780_common.h"
 
 /* LCD commands */
+#define LCD_CMD_DISPLAY_CLEAR	0x01	/* Clear entire display */
+
 #define LCD_CMD_SET_DDRAM_ADDR	0x80	/* Set display data RAM address */
 
+/* sleeps that many milliseconds with a reschedule */
+static void long_sleep(int ms)
+{
+	schedule_timeout_interruptible(msecs_to_jiffies(ms));
+}
+
 int hd44780_common_print(struct charlcd *lcd, int c)
 {
 	struct hd44780_common *hdc = lcd->drvdata;
@@ -49,6 +58,18 @@ int hd44780_common_home(struct charlcd *lcd)
 }
 EXPORT_SYMBOL_GPL(hd44780_common_home);
 
+/* clears the display and resets X/Y */
+int hd44780_common_clear_display(struct charlcd *lcd)
+{
+	struct hd44780_common *hdc = lcd->drvdata;
+
+	hdc->write_cmd(hdc, LCD_CMD_DISPLAY_CLEAR);
+	/* we must wait a few milliseconds (15) */
+	long_sleep(15);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(hd44780_common_clear_display);
+
 struct hd44780_common *hd44780_common_alloc(void)
 {
 	struct hd44780_common *hd;
diff --git a/drivers/auxdisplay/hd44780_common.h b/drivers/auxdisplay/hd44780_common.h
index c91070ed931b..ef11935a3764 100644
--- a/drivers/auxdisplay/hd44780_common.h
+++ b/drivers/auxdisplay/hd44780_common.h
@@ -17,4 +17,5 @@ struct hd44780_common {
 int hd44780_common_print(struct charlcd *lcd, int c);
 int hd44780_common_gotoxy(struct charlcd *lcd);
 int hd44780_common_home(struct charlcd *lcd);
+int hd44780_common_clear_display(struct charlcd *lcd);
 struct hd44780_common *hd44780_common_alloc(void);
diff --git a/drivers/auxdisplay/panel.c b/drivers/auxdisplay/panel.c
index b1e874f07456..8adf627529f1 100644
--- a/drivers/auxdisplay/panel.c
+++ b/drivers/auxdisplay/panel.c
@@ -877,6 +877,7 @@ static const struct charlcd_ops charlcd_serial_ops = {
 	.backlight	= lcd_backlight,
 	.gotoxy		= hd44780_common_gotoxy,
 	.home		= hd44780_common_home,
+	.clear_display	= hd44780_common_clear_display,
 };
 
 static const struct charlcd_ops charlcd_parallel_ops = {
@@ -884,6 +885,7 @@ static const struct charlcd_ops charlcd_parallel_ops = {
 	.backlight	= lcd_backlight,
 	.gotoxy		= hd44780_common_gotoxy,
 	.home		= hd44780_common_home,
+	.clear_display	= hd44780_common_clear_display,
 };
 
 static const struct charlcd_ops charlcd_tilcd_ops = {
@@ -891,6 +893,7 @@ static const struct charlcd_ops charlcd_tilcd_ops = {
 	.backlight	= lcd_backlight,
 	.gotoxy		= hd44780_common_gotoxy,
 	.home		= hd44780_common_home,
+	.clear_display	= hd44780_common_clear_display,
 };
 
 /* initialize the LCD driver */
-- 
2.28.0

[PATCH v5 12/25] auxdisplay: make charlcd_backlight visible to hd44780_common

[poeschel]

From: Lars Poeschel <poeschel@lemonage.de>

hd44780_common wants to use the charlcd_backlight function, so make it
visible.

Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
 drivers/auxdisplay/charlcd.c | 3 ++-
 drivers/auxdisplay/charlcd.h | 1 +
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index fc0daf4987d5..154419513186 100644
--- a/drivers/auxdisplay/charlcd.c
+++ b/drivers/auxdisplay/charlcd.c
@@ -91,7 +91,7 @@ static void long_sleep(int ms)
 }
 
 /* turn the backlight on or off */
-static void charlcd_backlight(struct charlcd *lcd, enum charlcd_onoff on)
+void charlcd_backlight(struct charlcd *lcd, enum charlcd_onoff on)
 {
 	struct charlcd_priv *priv = charlcd_to_priv(lcd);
 
@@ -103,6 +103,7 @@ static void charlcd_backlight(struct charlcd *lcd, enum charlcd_onoff on)
 		lcd->ops->backlight(lcd, on);
 	mutex_unlock(&priv->bl_tempo_lock);
 }
+EXPORT_SYMBOL_GPL(charlcd_backlight);
 
 static void charlcd_bl_off(struct work_struct *work)
 {
diff --git a/drivers/auxdisplay/charlcd.h b/drivers/auxdisplay/charlcd.h
index a6c32c4d1aac..a3210305cae7 100644
--- a/drivers/auxdisplay/charlcd.h
+++ b/drivers/auxdisplay/charlcd.h
@@ -56,6 +56,7 @@ struct charlcd_ops {
 	int (*clear_display)(struct charlcd *lcd);
 };
 
+void charlcd_backlight(struct charlcd *lcd, enum charlcd_onoff on);
 struct charlcd *charlcd_alloc(void);
 void charlcd_free(struct charlcd *lcd);
 
-- 
2.28.0

[PATCH v5 13/25] auxdisplay: Make use of enum for backlight on / off

[poeschel]

From: Lars Poeschel <poeschel@lemonage.de>

To turn the backlight on or off use our new enum CHARLCD_ON /
CHARLCD_OFF.

Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
 drivers/auxdisplay/charlcd.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index 154419513186..9631f70e8128 100644
--- a/drivers/auxdisplay/charlcd.c
+++ b/drivers/auxdisplay/charlcd.c
@@ -115,7 +115,7 @@ static void charlcd_bl_off(struct work_struct *work)
 	if (priv->bl_tempo) {
 		priv->bl_tempo = false;
 		if (!(priv->flags & LCD_FLAG_L))
-			priv->lcd.ops->backlight(&priv->lcd, 0);
+			priv->lcd.ops->backlight(&priv->lcd, CHARLCD_OFF);
 	}
 	mutex_unlock(&priv->bl_tempo_lock);
 }
@@ -132,7 +132,7 @@ void charlcd_poke(struct charlcd *lcd)
 
 	mutex_lock(&priv->bl_tempo_lock);
 	if (!priv->bl_tempo && !(priv->flags & LCD_FLAG_L))
-		lcd->ops->backlight(lcd, 1);
+		lcd->ops->backlight(lcd, CHARLCD_ON);
 	priv->bl_tempo = true;
 	schedule_delayed_work(&priv->bl_work, LCD_BL_TEMPO_PERIOD * HZ);
 	mutex_unlock(&priv->bl_tempo_lock);
@@ -829,7 +829,7 @@ int charlcd_unregister(struct charlcd *lcd)
 	the_charlcd = NULL;
 	if (lcd->ops->backlight) {
 		cancel_delayed_work_sync(&priv->bl_work);
-		priv->lcd.ops->backlight(&priv->lcd, 0);
+		priv->lcd.ops->backlight(&priv->lcd, CHARLCD_OFF);
 	}
 
 	return 0;
-- 
2.28.0

[PATCH v5 14/25] auxdisplay: Move init_display to hd44780_common

[poeschel]

From: Lars Poeschel <poeschel@lemonage.de>

The init_display function is moved over to hd44780_common. charlcd uses
it via its ops function pointer and drivers initialize the ops with the
common hd44780_common_init_display function.

Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
Changes in v5:
- Fix commit message typo: it's -> its
---
 drivers/auxdisplay/charlcd.c        | 95 ++---------------------------
 drivers/auxdisplay/charlcd.h        |  9 +++
 drivers/auxdisplay/hd44780.c        |  2 +
 drivers/auxdisplay/hd44780_common.c | 88 ++++++++++++++++++++++++++
 drivers/auxdisplay/hd44780_common.h |  2 +
 drivers/auxdisplay/panel.c          |  3 +
 6 files changed, 110 insertions(+), 89 deletions(-)

diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index 9631f70e8128..94f6b0afab13 100644
--- a/drivers/auxdisplay/charlcd.c
+++ b/drivers/auxdisplay/charlcd.c
@@ -8,7 +8,6 @@
 
 #include <linux/atomic.h>
 #include <linux/ctype.h>
-#include <linux/delay.h>
 #include <linux/fs.h>
 #include <linux/miscdevice.h>
 #include <linux/module.h>
@@ -26,17 +25,7 @@
 /* Keep the backlight on this many seconds for each flash */
 #define LCD_BL_TEMPO_PERIOD	4
 
-#define LCD_FLAG_B		0x0004	/* Blink on */
-#define LCD_FLAG_C		0x0008	/* Cursor on */
-#define LCD_FLAG_D		0x0010	/* Display on */
-#define LCD_FLAG_F		0x0020	/* Large font mode */
-#define LCD_FLAG_N		0x0040	/* 2-rows mode */
-#define LCD_FLAG_L		0x0080	/* Backlight enabled */
-
 /* LCD commands */
-#define LCD_CMD_ENTRY_MODE	0x04	/* Set entry mode */
-#define LCD_CMD_CURSOR_INC	0x02	/* Increment cursor */
-
 #define LCD_CMD_DISPLAY_CTRL	0x08	/* Display control */
 #define LCD_CMD_DISPLAY_ON	0x04	/* Set display on */
 #define LCD_CMD_CURSOR_ON	0x02	/* Set cursor on */
@@ -84,12 +73,6 @@ struct charlcd_priv {
 /* Device single-open policy control */
 static atomic_t charlcd_available = ATOMIC_INIT(1);
 
-/* sleeps that many milliseconds with a reschedule */
-static void long_sleep(int ms)
-{
-	schedule_timeout_interruptible(msecs_to_jiffies(ms));
-}
-
 /* turn the backlight on or off */
 void charlcd_backlight(struct charlcd *lcd, enum charlcd_onoff on)
 {
@@ -177,76 +160,6 @@ static void charlcd_clear_fast(struct charlcd *lcd)
 	charlcd_home(lcd);
 }
 
-static int charlcd_init_display(struct charlcd *lcd)
-{
-	void (*write_cmd_raw)(struct hd44780_common *hdc, int cmd);
-	struct charlcd_priv *priv = charlcd_to_priv(lcd);
-	struct hd44780_common *hdc = lcd->drvdata;
-	u8 init;
-
-	if (hdc->ifwidth != 4 && hdc->ifwidth != 8)
-		return -EINVAL;
-
-	priv->flags = ((lcd->height > 1) ? LCD_FLAG_N : 0) | LCD_FLAG_D |
-		      LCD_FLAG_C | LCD_FLAG_B;
-
-	long_sleep(20);		/* wait 20 ms after power-up for the paranoid */
-
-	/*
-	 * 8-bit mode, 1 line, small fonts; let's do it 3 times, to make sure
-	 * the LCD is in 8-bit mode afterwards
-	 */
-	init = LCD_CMD_FUNCTION_SET | LCD_CMD_DATA_LEN_8BITS;
-	if (hdc->ifwidth == 4) {
-		init >>= 4;
-		write_cmd_raw = hdc->write_cmd_raw4;
-	} else {
-		write_cmd_raw = hdc->write_cmd;
-	}
-	write_cmd_raw(hdc, init);
-	long_sleep(10);
-	write_cmd_raw(hdc, init);
-	long_sleep(10);
-	write_cmd_raw(hdc, init);
-	long_sleep(10);
-
-	if (hdc->ifwidth == 4) {
-		/* Switch to 4-bit mode, 1 line, small fonts */
-		hdc->write_cmd_raw4(hdc, LCD_CMD_FUNCTION_SET >> 4);
-		long_sleep(10);
-	}
-
-	/* set font height and lines number */
-	hdc->write_cmd(hdc,
-		LCD_CMD_FUNCTION_SET |
-		((hdc->ifwidth == 8) ? LCD_CMD_DATA_LEN_8BITS : 0) |
-		((priv->flags & LCD_FLAG_F) ? LCD_CMD_FONT_5X10_DOTS : 0) |
-		((priv->flags & LCD_FLAG_N) ? LCD_CMD_TWO_LINES : 0));
-	long_sleep(10);
-
-	/* display off, cursor off, blink off */
-	hdc->write_cmd(hdc, LCD_CMD_DISPLAY_CTRL);
-	long_sleep(10);
-
-	hdc->write_cmd(hdc,
-		LCD_CMD_DISPLAY_CTRL |	/* set display mode */
-		((priv->flags & LCD_FLAG_D) ? LCD_CMD_DISPLAY_ON : 0) |
-		((priv->flags & LCD_FLAG_C) ? LCD_CMD_CURSOR_ON : 0) |
-		((priv->flags & LCD_FLAG_B) ? LCD_CMD_BLINK_ON : 0));
-
-	charlcd_backlight(lcd, (priv->flags & LCD_FLAG_L) ? 1 : 0);
-
-	long_sleep(10);
-
-	/* entry mode set : increment, cursor shifting */
-	hdc->write_cmd(hdc, LCD_CMD_ENTRY_MODE | LCD_CMD_CURSOR_INC);
-
-	lcd->ops->clear_display(lcd);
-	lcd->addr.x = 0;
-	lcd->addr.y = 0;
-	return 0;
-}
-
 /*
  * Parses a movement command of the form "(.*);", where the group can be
  * any number of subcommands of the form "(x|y)[0-9]+".
@@ -418,7 +331,9 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 		break;
 	}
 	case 'I':	/* reinitialize display */
-		charlcd_init_display(lcd);
+		lcd->ops->init_display(lcd);
+		priv->flags = ((lcd->height > 1) ? LCD_FLAG_N : 0) | LCD_FLAG_D |
+			LCD_FLAG_C | LCD_FLAG_B;
 		processed = 1;
 		break;
 	case 'G': {
@@ -727,6 +642,8 @@ static int charlcd_init(struct charlcd *lcd)
 	struct charlcd_priv *priv = charlcd_to_priv(lcd);
 	int ret;
 
+	priv->flags = ((lcd->height > 1) ? LCD_FLAG_N : 0) | LCD_FLAG_D |
+		      LCD_FLAG_C | LCD_FLAG_B;
 	if (lcd->ops->backlight) {
 		mutex_init(&priv->bl_tempo_lock);
 		INIT_DELAYED_WORK(&priv->bl_work, charlcd_bl_off);
@@ -737,7 +654,7 @@ static int charlcd_init(struct charlcd *lcd)
 	 * Since charlcd_init_display() needs to write data, we have to
 	 * enable mark the LCD initialized just before.
 	 */
-	ret = charlcd_init_display(lcd);
+	ret = lcd->ops->init_display(lcd);
 	if (ret)
 		return ret;
 
diff --git a/drivers/auxdisplay/charlcd.h b/drivers/auxdisplay/charlcd.h
index a3210305cae7..dd40fd814a57 100644
--- a/drivers/auxdisplay/charlcd.h
+++ b/drivers/auxdisplay/charlcd.h
@@ -9,6 +9,13 @@
 #ifndef _CHARLCD_H
 #define _CHARLCD_H
 
+#define LCD_FLAG_B		0x0004	/* Blink on */
+#define LCD_FLAG_C		0x0008	/* Cursor on */
+#define LCD_FLAG_D		0x0010	/* Display on */
+#define LCD_FLAG_F		0x0020	/* Large font mode */
+#define LCD_FLAG_N		0x0040	/* 2-rows mode */
+#define LCD_FLAG_L		0x0080	/* Backlight enabled */
+
 enum charlcd_onoff {
 	CHARLCD_OFF = 0,
 	CHARLCD_ON,
@@ -46,6 +53,7 @@ struct charlcd {
  * @clear_display: Again clear the whole display, set the cursor to 0, 0. The
  * values in addr.x and addr.y are set to 0, 0 by charlcd prior to calling this
  * function.
+ * @init_display: Initialize the display.
  */
 struct charlcd_ops {
 	void (*clear_fast)(struct charlcd *lcd);
@@ -54,6 +62,7 @@ struct charlcd_ops {
 	int (*gotoxy)(struct charlcd *lcd);
 	int (*home)(struct charlcd *lcd);
 	int (*clear_display)(struct charlcd *lcd);
+	int (*init_display)(struct charlcd *lcd);
 };
 
 void charlcd_backlight(struct charlcd *lcd, enum charlcd_onoff on);
diff --git a/drivers/auxdisplay/hd44780.c b/drivers/auxdisplay/hd44780.c
index 40ea6d25dbe1..5916da09f738 100644
--- a/drivers/auxdisplay/hd44780.c
+++ b/drivers/auxdisplay/hd44780.c
@@ -130,6 +130,7 @@ static const struct charlcd_ops hd44780_ops_gpio8 = {
 	.gotoxy		= hd44780_common_gotoxy,
 	.home		= hd44780_common_home,
 	.clear_display	= hd44780_common_clear_display,
+	.init_display	= hd44780_common_init_display,
 };
 
 /* Send a command to the LCD panel in 4 bit GPIO mode */
@@ -177,6 +178,7 @@ static const struct charlcd_ops hd44780_ops_gpio4 = {
 	.gotoxy		= hd44780_common_gotoxy,
 	.home		= hd44780_common_home,
 	.clear_display	= hd44780_common_clear_display,
+	.init_display	= hd44780_common_init_display,
 };
 
 static int hd44780_probe(struct platform_device *pdev)
diff --git a/drivers/auxdisplay/hd44780_common.c b/drivers/auxdisplay/hd44780_common.c
index 2f7d55668eb4..7d4aea36cc55 100644
--- a/drivers/auxdisplay/hd44780_common.c
+++ b/drivers/auxdisplay/hd44780_common.c
@@ -9,6 +9,19 @@
 /* LCD commands */
 #define LCD_CMD_DISPLAY_CLEAR	0x01	/* Clear entire display */
 
+#define LCD_CMD_ENTRY_MODE	0x04	/* Set entry mode */
+#define LCD_CMD_CURSOR_INC	0x02	/* Increment cursor */
+
+#define LCD_CMD_DISPLAY_CTRL	0x08	/* Display control */
+#define LCD_CMD_DISPLAY_ON	0x04	/* Set display on */
+#define LCD_CMD_CURSOR_ON	0x02	/* Set cursor on */
+#define LCD_CMD_BLINK_ON	0x01	/* Set blink on */
+
+#define LCD_CMD_FUNCTION_SET	0x20	/* Set function */
+#define LCD_CMD_DATA_LEN_8BITS	0x10	/* Set data length to 8 bits */
+#define LCD_CMD_TWO_LINES	0x08	/* Set to two display lines */
+#define LCD_CMD_FONT_5X10_DOTS	0x04	/* Set char font to 5x10 dots */
+
 #define LCD_CMD_SET_DDRAM_ADDR	0x80	/* Set display data RAM address */
 
 /* sleeps that many milliseconds with a reschedule */
@@ -70,6 +83,81 @@ int hd44780_common_clear_display(struct charlcd *lcd)
 }
 EXPORT_SYMBOL_GPL(hd44780_common_clear_display);
 
+int hd44780_common_init_display(struct charlcd *lcd)
+{
+	struct hd44780_common *hdc = lcd->drvdata;
+
+	void (*write_cmd_raw)(struct hd44780_common *hdc, int cmd);
+	u8 init;
+
+	if (hdc->ifwidth != 4 && hdc->ifwidth != 8)
+		return -EINVAL;
+
+	hdc->hd44780_common_flags = ((lcd->height > 1) ? LCD_FLAG_N : 0) |
+		LCD_FLAG_D | LCD_FLAG_C | LCD_FLAG_B;
+
+	long_sleep(20);		/* wait 20 ms after power-up for the paranoid */
+
+	/*
+	 * 8-bit mode, 1 line, small fonts; let's do it 3 times, to make sure
+	 * the LCD is in 8-bit mode afterwards
+	 */
+	init = LCD_CMD_FUNCTION_SET | LCD_CMD_DATA_LEN_8BITS;
+	if (hdc->ifwidth == 4) {
+		init >>= 4;
+		write_cmd_raw = hdc->write_cmd_raw4;
+	} else {
+		write_cmd_raw = hdc->write_cmd;
+	}
+	write_cmd_raw(hdc, init);
+	long_sleep(10);
+	write_cmd_raw(hdc, init);
+	long_sleep(10);
+	write_cmd_raw(hdc, init);
+	long_sleep(10);
+
+	if (hdc->ifwidth == 4) {
+		/* Switch to 4-bit mode, 1 line, small fonts */
+		hdc->write_cmd_raw4(hdc, LCD_CMD_FUNCTION_SET >> 4);
+		long_sleep(10);
+	}
+
+	/* set font height and lines number */
+	hdc->write_cmd(hdc,
+		LCD_CMD_FUNCTION_SET |
+		((hdc->ifwidth == 8) ? LCD_CMD_DATA_LEN_8BITS : 0) |
+		((hdc->hd44780_common_flags & LCD_FLAG_F) ?
+			LCD_CMD_FONT_5X10_DOTS : 0) |
+		((hdc->hd44780_common_flags & LCD_FLAG_N) ?
+			LCD_CMD_TWO_LINES : 0));
+	long_sleep(10);
+
+	/* display off, cursor off, blink off */
+	hdc->write_cmd(hdc, LCD_CMD_DISPLAY_CTRL);
+	long_sleep(10);
+
+	hdc->write_cmd(hdc,
+		LCD_CMD_DISPLAY_CTRL |	/* set display mode */
+		((hdc->hd44780_common_flags & LCD_FLAG_D) ?
+			LCD_CMD_DISPLAY_ON : 0) |
+		((hdc->hd44780_common_flags & LCD_FLAG_C) ?
+			LCD_CMD_CURSOR_ON : 0) |
+		((hdc->hd44780_common_flags & LCD_FLAG_B) ?
+			LCD_CMD_BLINK_ON : 0));
+
+	charlcd_backlight(lcd,
+			(hdc->hd44780_common_flags & LCD_FLAG_L) ? 1 : 0);
+
+	long_sleep(10);
+
+	/* entry mode set : increment, cursor shifting */
+	hdc->write_cmd(hdc, LCD_CMD_ENTRY_MODE | LCD_CMD_CURSOR_INC);
+
+	hd44780_common_clear_display(lcd);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(hd44780_common_init_display);
+
 struct hd44780_common *hd44780_common_alloc(void)
 {
 	struct hd44780_common *hd;
diff --git a/drivers/auxdisplay/hd44780_common.h b/drivers/auxdisplay/hd44780_common.h
index ef11935a3764..a8e322891ce2 100644
--- a/drivers/auxdisplay/hd44780_common.h
+++ b/drivers/auxdisplay/hd44780_common.h
@@ -7,6 +7,7 @@ struct hd44780_common {
 	int ifwidth;			/* 4-bit or 8-bit (default) */
 	int bwidth;			/* Default set by hd44780_alloc() */
 	int hwidth;			/* Default set by hd44780_alloc() */
+	unsigned long hd44780_common_flags;
 	void (*write_data)(struct hd44780_common *hdc, int data);
 	void (*write_cmd)(struct hd44780_common *hdc, int cmd);
 	/* write_cmd_raw4 is for 4-bit connected displays only */
@@ -18,4 +19,5 @@ int hd44780_common_print(struct charlcd *lcd, int c);
 int hd44780_common_gotoxy(struct charlcd *lcd);
 int hd44780_common_home(struct charlcd *lcd);
 int hd44780_common_clear_display(struct charlcd *lcd);
+int hd44780_common_init_display(struct charlcd *lcd);
 struct hd44780_common *hd44780_common_alloc(void);
diff --git a/drivers/auxdisplay/panel.c b/drivers/auxdisplay/panel.c
index 8adf627529f1..583bd22d3abd 100644
--- a/drivers/auxdisplay/panel.c
+++ b/drivers/auxdisplay/panel.c
@@ -878,6 +878,7 @@ static const struct charlcd_ops charlcd_serial_ops = {
 	.gotoxy		= hd44780_common_gotoxy,
 	.home		= hd44780_common_home,
 	.clear_display	= hd44780_common_clear_display,
+	.init_display	= hd44780_common_init_display,
 };
 
 static const struct charlcd_ops charlcd_parallel_ops = {
@@ -886,6 +887,7 @@ static const struct charlcd_ops charlcd_parallel_ops = {
 	.gotoxy		= hd44780_common_gotoxy,
 	.home		= hd44780_common_home,
 	.clear_display	= hd44780_common_clear_display,
+	.init_display	= hd44780_common_init_display,
 };
 
 static const struct charlcd_ops charlcd_tilcd_ops = {
@@ -894,6 +896,7 @@ static const struct charlcd_ops charlcd_tilcd_ops = {
 	.gotoxy		= hd44780_common_gotoxy,
 	.home		= hd44780_common_home,
 	.clear_display	= hd44780_common_clear_display,
+	.init_display	= hd44780_common_init_display,
 };
 
 /* initialize the LCD driver */
-- 
2.28.0

[PATCH v5 15/25] auxdisplay: implement various hd44780_common_ functions

[poeschel]

From: Lars Poeschel <poeschel@lemonage.de>

This implements various hd44780_common_ functions for hd44780 compatible
display drivers to use. charlcd then calls these functions through its
ops function pointer.
The functions namely are:
- hd44780_common_shift_cursor
- hd44780_common_display_shift
- hd44780_common_display
- hd44780_common_cursor
- hd44780_common_blink
- hd44780_common_fontsize
- hd44780_common_lines

Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
Changes in v5:
- this patch is squashed together from the former individual
  hd44780_common_ function patches
---
 drivers/auxdisplay/charlcd.c        |  73 ++++++++++------
 drivers/auxdisplay/charlcd.h        |  28 ++++++
 drivers/auxdisplay/hd44780.c        |  14 +++
 drivers/auxdisplay/hd44780_common.c | 131 ++++++++++++++++++++++++++++
 drivers/auxdisplay/hd44780_common.h |   9 ++
 drivers/auxdisplay/panel.c          |  21 +++++
 6 files changed, 249 insertions(+), 27 deletions(-)

diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index 94f6b0afab13..281a3259c144 100644
--- a/drivers/auxdisplay/charlcd.c
+++ b/drivers/auxdisplay/charlcd.c
@@ -31,10 +31,6 @@
 #define LCD_CMD_CURSOR_ON	0x02	/* Set cursor on */
 #define LCD_CMD_BLINK_ON	0x01	/* Set blink on */
 
-#define LCD_CMD_SHIFT		0x10	/* Shift cursor/display */
-#define LCD_CMD_DISPLAY_SHIFT	0x08	/* Shift display instead of cursor */
-#define LCD_CMD_SHIFT_RIGHT	0x04	/* Shift display/cursor to the right */
-
 #define LCD_CMD_FUNCTION_SET	0x20	/* Set function */
 #define LCD_CMD_DATA_LEN_8BITS	0x10	/* Set data length to 8 bits */
 #define LCD_CMD_TWO_LINES	0x08	/* Set to two display lines */
@@ -236,26 +232,44 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 	switch (*esc) {
 	case 'D':	/* Display ON */
 		priv->flags |= LCD_FLAG_D;
+		if (priv->flags != oldflags)
+			lcd->ops->display(lcd, CHARLCD_ON);
+
 		processed = 1;
 		break;
 	case 'd':	/* Display OFF */
 		priv->flags &= ~LCD_FLAG_D;
+		if (priv->flags != oldflags)
+			lcd->ops->display(lcd, CHARLCD_OFF);
+
 		processed = 1;
 		break;
 	case 'C':	/* Cursor ON */
 		priv->flags |= LCD_FLAG_C;
+		if (priv->flags != oldflags)
+			lcd->ops->cursor(lcd, CHARLCD_ON);
+
 		processed = 1;
 		break;
 	case 'c':	/* Cursor OFF */
 		priv->flags &= ~LCD_FLAG_C;
+		if (priv->flags != oldflags)
+			lcd->ops->cursor(lcd, CHARLCD_OFF);
+
 		processed = 1;
 		break;
 	case 'B':	/* Blink ON */
 		priv->flags |= LCD_FLAG_B;
+		if (priv->flags != oldflags)
+			lcd->ops->blink(lcd, CHARLCD_ON);
+
 		processed = 1;
 		break;
 	case 'b':	/* Blink OFF */
 		priv->flags &= ~LCD_FLAG_B;
+		if (priv->flags != oldflags)
+			lcd->ops->blink(lcd, CHARLCD_OFF);
+
 		processed = 1;
 		break;
 	case '+':	/* Back light ON */
@@ -272,47 +286,54 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 		break;
 	case 'f':	/* Small Font */
 		priv->flags &= ~LCD_FLAG_F;
+		if (priv->flags != oldflags)
+			lcd->ops->fontsize(lcd, CHARLCD_FONTSIZE_SMALL);
+
 		processed = 1;
 		break;
 	case 'F':	/* Large Font */
 		priv->flags |= LCD_FLAG_F;
+		if (priv->flags != oldflags)
+			lcd->ops->fontsize(lcd, CHARLCD_FONTSIZE_LARGE);
+
 		processed = 1;
 		break;
 	case 'n':	/* One Line */
 		priv->flags &= ~LCD_FLAG_N;
+		if (priv->flags != oldflags)
+			lcd->ops->lines(lcd, CHARLCD_LINES_1);
+
 		processed = 1;
 		break;
 	case 'N':	/* Two Lines */
 		priv->flags |= LCD_FLAG_N;
+		if (priv->flags != oldflags)
+			lcd->ops->lines(lcd, CHARLCD_LINES_2);
+
 		processed = 1;
 		break;
 	case 'l':	/* Shift Cursor Left */
 		if (lcd->addr.x > 0) {
-			/* back one char if not at end of line */
-			if (lcd->addr.x < hdc->bwidth)
-				hdc->write_cmd(hdc, LCD_CMD_SHIFT);
-			lcd->addr.x--;
+			if (!lcd->ops->shift_cursor(lcd, CHARLCD_SHIFT_LEFT))
+				lcd->addr.x--;
 		}
+
 		processed = 1;
 		break;
 	case 'r':	/* shift cursor right */
 		if (lcd->addr.x < lcd->width) {
-			/* allow the cursor to pass the end of the line */
-			if (lcd->addr.x < (hdc->bwidth - 1))
-				hdc->write_cmd(hdc,
-					LCD_CMD_SHIFT | LCD_CMD_SHIFT_RIGHT);
-			lcd->addr.x++;
+			if (!lcd->ops->shift_cursor(lcd, CHARLCD_SHIFT_RIGHT))
+				lcd->addr.x++;
 		}
+
 		processed = 1;
 		break;
 	case 'L':	/* shift display left */
-		hdc->write_cmd(hdc, LCD_CMD_SHIFT | LCD_CMD_DISPLAY_SHIFT);
+		lcd->ops->shift_display(lcd, CHARLCD_SHIFT_LEFT);
 		processed = 1;
 		break;
 	case 'R':	/* shift display right */
-		hdc->write_cmd(hdc,
-				    LCD_CMD_SHIFT | LCD_CMD_DISPLAY_SHIFT |
-				    LCD_CMD_SHIFT_RIGHT);
+		lcd->ops->shift_display(lcd, CHARLCD_SHIFT_RIGHT);
 		processed = 1;
 		break;
 	case 'k': {	/* kill end of line */
@@ -456,19 +477,17 @@ static void charlcd_write_char(struct charlcd *lcd, char c)
 		case '\b':
 			/* go back one char and clear it */
 			if (lcd->addr.x > 0) {
-				/*
-				 * check if we're not at the
-				 * end of the line
-				 */
-				if (lcd->addr.x < hdc->bwidth)
-					/* back one char */
-					hdc->write_cmd(hdc, LCD_CMD_SHIFT);
-				lcd->addr.x--;
+				/* back one char */
+				if (!lcd->ops->shift_cursor(lcd,
+							CHARLCD_SHIFT_LEFT))
+					lcd->addr.x--;
 			}
 			/* replace with a space */
-			hdc->write_data(hdc, ' ');
+			charlcd_print(lcd, ' ');
 			/* back one char again */
-			hdc->write_cmd(hdc, LCD_CMD_SHIFT);
+			if (!lcd->ops->shift_cursor(lcd, CHARLCD_SHIFT_LEFT))
+				lcd->addr.x--;
+
 			break;
 		case '\f':
 			/* quickly clear the display */
diff --git a/drivers/auxdisplay/charlcd.h b/drivers/auxdisplay/charlcd.h
index dd40fd814a57..5a89bdeb659a 100644
--- a/drivers/auxdisplay/charlcd.h
+++ b/drivers/auxdisplay/charlcd.h
@@ -21,6 +21,21 @@ enum charlcd_onoff {
 	CHARLCD_ON,
 };
 
+enum charlcd_shift_dir {
+	CHARLCD_SHIFT_LEFT,
+	CHARLCD_SHIFT_RIGHT,
+};
+
+enum charlcd_fontsize {
+	CHARLCD_FONTSIZE_SMALL,
+	CHARLCD_FONTSIZE_LARGE,
+};
+
+enum charlcd_lines {
+	CHARLCD_LINES_1,
+	CHARLCD_LINES_2,
+};
+
 struct charlcd {
 	const struct charlcd_ops *ops;
 	const unsigned char *char_conv;	/* Optional */
@@ -54,6 +69,12 @@ struct charlcd {
  * values in addr.x and addr.y are set to 0, 0 by charlcd prior to calling this
  * function.
  * @init_display: Initialize the display.
+ * @shift_cursor: Shift cursor left or right one position.
+ * @shift_display: Shift whole display content left or right.
+ * @display: Turn display on or off.
+ * @cursor: Turn cursor on or off.
+ * @blink: Turn cursor blink on or off.
+ * @lines: One or two lines.
  */
 struct charlcd_ops {
 	void (*clear_fast)(struct charlcd *lcd);
@@ -63,6 +84,13 @@ struct charlcd_ops {
 	int (*home)(struct charlcd *lcd);
 	int (*clear_display)(struct charlcd *lcd);
 	int (*init_display)(struct charlcd *lcd);
+	int (*shift_cursor)(struct charlcd *lcd, enum charlcd_shift_dir dir);
+	int (*shift_display)(struct charlcd *lcd, enum charlcd_shift_dir dir);
+	int (*display)(struct charlcd *lcd, enum charlcd_onoff on);
+	int (*cursor)(struct charlcd *lcd, enum charlcd_onoff on);
+	int (*blink)(struct charlcd *lcd, enum charlcd_onoff on);
+	int (*fontsize)(struct charlcd *lcd, enum charlcd_fontsize size);
+	int (*lines)(struct charlcd *lcd, enum charlcd_lines lines);
 };
 
 void charlcd_backlight(struct charlcd *lcd, enum charlcd_onoff on);
diff --git a/drivers/auxdisplay/hd44780.c b/drivers/auxdisplay/hd44780.c
index 5916da09f738..7b7b28d72198 100644
--- a/drivers/auxdisplay/hd44780.c
+++ b/drivers/auxdisplay/hd44780.c
@@ -131,6 +131,13 @@ static const struct charlcd_ops hd44780_ops_gpio8 = {
 	.home		= hd44780_common_home,
 	.clear_display	= hd44780_common_clear_display,
 	.init_display	= hd44780_common_init_display,
+	.shift_cursor	= hd44780_common_shift_cursor,
+	.shift_display	= hd44780_common_shift_display,
+	.display	= hd44780_common_display,
+	.cursor		= hd44780_common_cursor,
+	.blink		= hd44780_common_blink,
+	.fontsize	= hd44780_common_fontsize,
+	.lines		= hd44780_common_lines,
 };
 
 /* Send a command to the LCD panel in 4 bit GPIO mode */
@@ -179,6 +186,13 @@ static const struct charlcd_ops hd44780_ops_gpio4 = {
 	.home		= hd44780_common_home,
 	.clear_display	= hd44780_common_clear_display,
 	.init_display	= hd44780_common_init_display,
+	.shift_cursor	= hd44780_common_shift_cursor,
+	.shift_display	= hd44780_common_shift_display,
+	.display	= hd44780_common_display,
+	.cursor		= hd44780_common_cursor,
+	.blink		= hd44780_common_blink,
+	.fontsize	= hd44780_common_fontsize,
+	.lines		= hd44780_common_lines,
 };
 
 static int hd44780_probe(struct platform_device *pdev)
diff --git a/drivers/auxdisplay/hd44780_common.c b/drivers/auxdisplay/hd44780_common.c
index 7d4aea36cc55..9d538fdcd260 100644
--- a/drivers/auxdisplay/hd44780_common.c
+++ b/drivers/auxdisplay/hd44780_common.c
@@ -17,6 +17,10 @@
 #define LCD_CMD_CURSOR_ON	0x02	/* Set cursor on */
 #define LCD_CMD_BLINK_ON	0x01	/* Set blink on */
 
+#define LCD_CMD_SHIFT		0x10	/* Shift cursor/display */
+#define LCD_CMD_DISPLAY_SHIFT	0x08	/* Shift display instead of cursor */
+#define LCD_CMD_SHIFT_RIGHT	0x04	/* Shift display/cursor to the right */
+
 #define LCD_CMD_FUNCTION_SET	0x20	/* Set function */
 #define LCD_CMD_DATA_LEN_8BITS	0x10	/* Set data length to 8 bits */
 #define LCD_CMD_TWO_LINES	0x08	/* Set to two display lines */
@@ -158,6 +162,133 @@ int hd44780_common_init_display(struct charlcd *lcd)
 }
 EXPORT_SYMBOL_GPL(hd44780_common_init_display);
 
+int hd44780_common_shift_cursor(struct charlcd *lcd, enum charlcd_shift_dir dir)
+{
+	struct hd44780_common *hdc = lcd->drvdata;
+
+	if (dir == CHARLCD_SHIFT_LEFT) {
+		/* back one char if not at end of line */
+		if (lcd->addr.x < hdc->bwidth)
+			hdc->write_cmd(hdc, LCD_CMD_SHIFT);
+	} else if (dir == CHARLCD_SHIFT_RIGHT) {
+		/* allow the cursor to pass the end of the line */
+		if (lcd->addr.x < (hdc->bwidth - 1))
+			hdc->write_cmd(hdc,
+					LCD_CMD_SHIFT | LCD_CMD_SHIFT_RIGHT);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(hd44780_common_shift_cursor);
+
+int hd44780_common_shift_display(struct charlcd *lcd,
+		enum charlcd_shift_dir dir)
+{
+	struct hd44780_common *hdc = lcd->drvdata;
+
+	if (dir == CHARLCD_SHIFT_LEFT)
+		hdc->write_cmd(hdc, LCD_CMD_SHIFT | LCD_CMD_DISPLAY_SHIFT);
+	else if (dir == CHARLCD_SHIFT_RIGHT)
+		hdc->write_cmd(hdc, LCD_CMD_SHIFT | LCD_CMD_DISPLAY_SHIFT |
+			LCD_CMD_SHIFT_RIGHT);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(hd44780_common_shift_display);
+
+static void hd44780_common_set_mode(struct hd44780_common *hdc)
+{
+	hdc->write_cmd(hdc,
+		LCD_CMD_DISPLAY_CTRL |
+		((hdc->hd44780_common_flags & LCD_FLAG_D) ?
+			LCD_CMD_DISPLAY_ON : 0) |
+		((hdc->hd44780_common_flags & LCD_FLAG_C) ?
+			LCD_CMD_CURSOR_ON : 0) |
+		((hdc->hd44780_common_flags & LCD_FLAG_B) ?
+			LCD_CMD_BLINK_ON : 0));
+}
+
+int hd44780_common_display(struct charlcd *lcd, enum charlcd_onoff on)
+{
+	struct hd44780_common *hdc = lcd->drvdata;
+
+	if (on == CHARLCD_ON)
+		hdc->hd44780_common_flags |= LCD_FLAG_D;
+	else
+		hdc->hd44780_common_flags &= ~LCD_FLAG_D;
+
+	hd44780_common_set_mode(hdc);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(hd44780_common_display);
+
+int hd44780_common_cursor(struct charlcd *lcd, enum charlcd_onoff on)
+{
+	struct hd44780_common *hdc = lcd->drvdata;
+
+	if (on == CHARLCD_ON)
+		hdc->hd44780_common_flags |= LCD_FLAG_C;
+	else
+		hdc->hd44780_common_flags &= ~LCD_FLAG_C;
+
+	hd44780_common_set_mode(hdc);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(hd44780_common_cursor);
+
+int hd44780_common_blink(struct charlcd *lcd, enum charlcd_onoff on)
+{
+	struct hd44780_common *hdc = lcd->drvdata;
+
+	if (on == CHARLCD_ON)
+		hdc->hd44780_common_flags |= LCD_FLAG_B;
+	else
+		hdc->hd44780_common_flags &= ~LCD_FLAG_B;
+
+	hd44780_common_set_mode(hdc);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(hd44780_common_blink);
+
+static void hd44780_common_set_function(struct hd44780_common *hdc)
+{
+	hdc->write_cmd(hdc,
+		LCD_CMD_FUNCTION_SET |
+		((hdc->ifwidth == 8) ? LCD_CMD_DATA_LEN_8BITS : 0) |
+		((hdc->hd44780_common_flags & LCD_FLAG_F) ?
+			LCD_CMD_FONT_5X10_DOTS : 0) |
+		((hdc->hd44780_common_flags & LCD_FLAG_N) ?
+			LCD_CMD_TWO_LINES : 0));
+}
+
+int hd44780_common_fontsize(struct charlcd *lcd, enum charlcd_fontsize size)
+{
+	struct hd44780_common *hdc = lcd->drvdata;
+
+	if (size == CHARLCD_FONTSIZE_LARGE)
+		hdc->hd44780_common_flags |= LCD_FLAG_F;
+	else
+		hdc->hd44780_common_flags &= ~LCD_FLAG_F;
+
+	hd44780_common_set_function(hdc);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(hd44780_common_fontsize);
+
+int hd44780_common_lines(struct charlcd *lcd, enum charlcd_lines lines)
+{
+	struct hd44780_common *hdc = lcd->drvdata;
+
+	if (lines == CHARLCD_LINES_2)
+		hdc->hd44780_common_flags |= LCD_FLAG_N;
+	else
+		hdc->hd44780_common_flags &= ~LCD_FLAG_N;
+
+	hd44780_common_set_function(hdc);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(hd44780_common_lines);
+
 struct hd44780_common *hd44780_common_alloc(void)
 {
 	struct hd44780_common *hd;
diff --git a/drivers/auxdisplay/hd44780_common.h b/drivers/auxdisplay/hd44780_common.h
index a8e322891ce2..e5a69fdc3b61 100644
--- a/drivers/auxdisplay/hd44780_common.h
+++ b/drivers/auxdisplay/hd44780_common.h
@@ -20,4 +20,13 @@ int hd44780_common_gotoxy(struct charlcd *lcd);
 int hd44780_common_home(struct charlcd *lcd);
 int hd44780_common_clear_display(struct charlcd *lcd);
 int hd44780_common_init_display(struct charlcd *lcd);
+int hd44780_common_shift_cursor(struct charlcd *lcd,
+		enum charlcd_shift_dir dir);
+int hd44780_common_shift_display(struct charlcd *lcd,
+		enum charlcd_shift_dir dir);
+int hd44780_common_display(struct charlcd *lcd, enum charlcd_onoff on);
+int hd44780_common_cursor(struct charlcd *lcd, enum charlcd_onoff on);
+int hd44780_common_blink(struct charlcd *lcd, enum charlcd_onoff on);
+int hd44780_common_fontsize(struct charlcd *lcd, enum charlcd_fontsize size);
+int hd44780_common_lines(struct charlcd *lcd, enum charlcd_lines lines);
 struct hd44780_common *hd44780_common_alloc(void);
diff --git a/drivers/auxdisplay/panel.c b/drivers/auxdisplay/panel.c
index 583bd22d3abd..3d33d7cc979c 100644
--- a/drivers/auxdisplay/panel.c
+++ b/drivers/auxdisplay/panel.c
@@ -879,6 +879,13 @@ static const struct charlcd_ops charlcd_serial_ops = {
 	.home		= hd44780_common_home,
 	.clear_display	= hd44780_common_clear_display,
 	.init_display	= hd44780_common_init_display,
+	.shift_cursor	= hd44780_common_shift_cursor,
+	.shift_display	= hd44780_common_shift_display,
+	.display	= hd44780_common_display,
+	.cursor		= hd44780_common_cursor,
+	.blink		= hd44780_common_blink,
+	.fontsize	= hd44780_common_fontsize,
+	.lines		= hd44780_common_lines,
 };
 
 static const struct charlcd_ops charlcd_parallel_ops = {
@@ -888,6 +895,13 @@ static const struct charlcd_ops charlcd_parallel_ops = {
 	.home		= hd44780_common_home,
 	.clear_display	= hd44780_common_clear_display,
 	.init_display	= hd44780_common_init_display,
+	.shift_cursor	= hd44780_common_shift_cursor,
+	.shift_display	= hd44780_common_shift_display,
+	.display	= hd44780_common_display,
+	.cursor		= hd44780_common_cursor,
+	.blink		= hd44780_common_blink,
+	.fontsize	= hd44780_common_fontsize,
+	.lines		= hd44780_common_lines,
 };
 
 static const struct charlcd_ops charlcd_tilcd_ops = {
@@ -897,6 +911,13 @@ static const struct charlcd_ops charlcd_tilcd_ops = {
 	.home		= hd44780_common_home,
 	.clear_display	= hd44780_common_clear_display,
 	.init_display	= hd44780_common_init_display,
+	.shift_cursor	= hd44780_common_shift_cursor,
+	.shift_display	= hd44780_common_shift_display,
+	.display	= hd44780_common_display,
+	.cursor		= hd44780_common_cursor,
+	.blink		= hd44780_common_blink,
+	.fontsize	= hd44780_common_fontsize,
+	.lines		= hd44780_common_lines,
 };
 
 /* initialize the LCD driver */
-- 
2.28.0

[PATCH v5 16/25] auxdisplay: cleanup unnecessary hd44780 code in charlcd

[poeschel]

From: Lars Poeschel <poeschel@lemonage.de>

This cleans up now unnecessary hd44780 specific code from charlcd. We
obsoleted this with the last patch. So another chunk of hd44780 specific
code can be dropped from charlcd.

Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
Changes in v5:
- combined two cleanup patches
---
 drivers/auxdisplay/charlcd.c | 32 +-------------------------------
 1 file changed, 1 insertion(+), 31 deletions(-)

diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index 281a3259c144..29737c3e18f6 100644
--- a/drivers/auxdisplay/charlcd.c
+++ b/drivers/auxdisplay/charlcd.c
@@ -25,21 +25,8 @@
 /* Keep the backlight on this many seconds for each flash */
 #define LCD_BL_TEMPO_PERIOD	4
 
-/* LCD commands */
-#define LCD_CMD_DISPLAY_CTRL	0x08	/* Display control */
-#define LCD_CMD_DISPLAY_ON	0x04	/* Set display on */
-#define LCD_CMD_CURSOR_ON	0x02	/* Set cursor on */
-#define LCD_CMD_BLINK_ON	0x01	/* Set blink on */
-
-#define LCD_CMD_FUNCTION_SET	0x20	/* Set function */
-#define LCD_CMD_DATA_LEN_8BITS	0x10	/* Set data length to 8 bits */
-#define LCD_CMD_TWO_LINES	0x08	/* Set to two display lines */
-#define LCD_CMD_FONT_5X10_DOTS	0x04	/* Set char font to 5x10 dots */
-
 #define LCD_CMD_SET_CGRAM_ADDR	0x40	/* Set char generator RAM address */
 
-#define LCD_CMD_SET_DDRAM_ADDR 0x80    /* Set display data RAM address */
-
 #define LCD_ESCAPE_LEN		24	/* Max chars for LCD escape command */
 #define LCD_ESCAPE_CHAR		27	/* Use char 27 for escape command */
 
@@ -431,24 +418,7 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 	if (oldflags == priv->flags)
 		return processed;
 
-	/* check whether one of B,C,D flags were changed */
-	if ((oldflags ^ priv->flags) &
-	    (LCD_FLAG_B | LCD_FLAG_C | LCD_FLAG_D))
-		/* set display mode */
-		hdc->write_cmd(hdc,
-			LCD_CMD_DISPLAY_CTRL |
-			((priv->flags & LCD_FLAG_D) ? LCD_CMD_DISPLAY_ON : 0) |
-			((priv->flags & LCD_FLAG_C) ? LCD_CMD_CURSOR_ON : 0) |
-			((priv->flags & LCD_FLAG_B) ? LCD_CMD_BLINK_ON : 0));
-	/* check whether one of F,N flags was changed */
-	else if ((oldflags ^ priv->flags) & (LCD_FLAG_F | LCD_FLAG_N))
-		hdc->write_cmd(hdc,
-			LCD_CMD_FUNCTION_SET |
-			((hdc->ifwidth == 8) ? LCD_CMD_DATA_LEN_8BITS : 0) |
-			((priv->flags & LCD_FLAG_F) ? LCD_CMD_FONT_5X10_DOTS : 0) |
-			((priv->flags & LCD_FLAG_N) ? LCD_CMD_TWO_LINES : 0));
-	/* check whether L flag was changed */
-	else if ((oldflags ^ priv->flags) & LCD_FLAG_L)
+	if ((oldflags ^ priv->flags) & LCD_FLAG_L)
 		charlcd_backlight(lcd, !!(priv->flags & LCD_FLAG_L));
 
 	return processed;
-- 
2.28.0

[PATCH v5 17/25] auxdisplay: Move char redefine code to hd44780_common

[poeschel]

From: Lars Poeschel <poeschel@lemonage.de>

Take the code to redefine characters out of charlcd and move it to
hd44780_common, as this is hd44780 specific.
There is now a function hd44780_common_redefine_char that drivers use
and charlcd calls it through its ops function pointer.

Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
Changes in v5:
- I did previously undo commit 3f03b6498 which was a mistake. This is
  now corrected.
---
 drivers/auxdisplay/charlcd.c        | 60 +++--------------------------
 drivers/auxdisplay/charlcd.h        |  2 +
 drivers/auxdisplay/hd44780.c        |  2 +
 drivers/auxdisplay/hd44780_common.c | 57 +++++++++++++++++++++++++++
 drivers/auxdisplay/hd44780_common.h |  1 +
 drivers/auxdisplay/panel.c          |  3 ++
 6 files changed, 70 insertions(+), 55 deletions(-)

diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index 29737c3e18f6..dca1b138a239 100644
--- a/drivers/auxdisplay/charlcd.c
+++ b/drivers/auxdisplay/charlcd.c
@@ -25,8 +25,6 @@
 /* Keep the backlight on this many seconds for each flash */
 #define LCD_BL_TEMPO_PERIOD	4
 
-#define LCD_CMD_SET_CGRAM_ADDR	0x40	/* Set char generator RAM address */
-
 #define LCD_ESCAPE_LEN		24	/* Max chars for LCD escape command */
 #define LCD_ESCAPE_CHAR		27	/* Use char 27 for escape command */
 
@@ -344,61 +342,13 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 			LCD_FLAG_C | LCD_FLAG_B;
 		processed = 1;
 		break;
-	case 'G': {
-		/* Generator : LGcxxxxx...xx; must have <c> between '0'
-		 * and '7', representing the numerical ASCII code of the
-		 * redefined character, and <xx...xx> a sequence of 16
-		 * hex digits representing 8 bytes for each character.
-		 * Most LCDs will only use 5 lower bits of the 7 first
-		 * bytes.
-		 */
-
-		unsigned char cgbytes[8];
-		unsigned char cgaddr;
-		int cgoffset;
-		int shift;
-		char value;
-		int addr;
-
-		if (!strchr(esc, ';'))
-			break;
-
-		esc++;
-
-		cgaddr = *(esc++) - '0';
-		if (cgaddr > 7) {
+	case 'G':
+		if (lcd->ops->redefine_char)
+			processed = lcd->ops->redefine_char(lcd, esc);
+		else
 			processed = 1;
-			break;
-		}
-
-		cgoffset = 0;
-		shift = 0;
-		value = 0;
-		while (*esc && cgoffset < 8) {
-			int half;
-
-			shift ^= 4;
-
-			half = hex_to_bin(*esc++);
-			if (half < 0)
-				continue;
-
-			value |= half << shift;
-			if (shift == 0) {
-				cgbytes[cgoffset++] = value;
-				value = 0;
-			}
-		}
-
-		hdc->write_cmd(hdc, LCD_CMD_SET_CGRAM_ADDR | (cgaddr * 8));
-		for (addr = 0; addr < cgoffset; addr++)
-			hdc->write_data(hdc, cgbytes[addr]);
-
-		/* ensures that we stop writing to CGRAM */
-		lcd->ops->gotoxy(lcd);
-		processed = 1;
 		break;
-	}
+
 	case 'x':	/* gotoxy : LxXXX[yYYY]; */
 	case 'y':	/* gotoxy : LyYYY[xXXX]; */
 		if (priv->esc_seq.buf[priv->esc_seq.len - 1] != ';')
diff --git a/drivers/auxdisplay/charlcd.h b/drivers/auxdisplay/charlcd.h
index 5a89bdeb659a..3339e8c2554e 100644
--- a/drivers/auxdisplay/charlcd.h
+++ b/drivers/auxdisplay/charlcd.h
@@ -75,6 +75,7 @@ struct charlcd {
  * @cursor: Turn cursor on or off.
  * @blink: Turn cursor blink on or off.
  * @lines: One or two lines.
+ * @redefine_char: Redefine the actual pixel matrix of character.
  */
 struct charlcd_ops {
 	void (*clear_fast)(struct charlcd *lcd);
@@ -91,6 +92,7 @@ struct charlcd_ops {
 	int (*blink)(struct charlcd *lcd, enum charlcd_onoff on);
 	int (*fontsize)(struct charlcd *lcd, enum charlcd_fontsize size);
 	int (*lines)(struct charlcd *lcd, enum charlcd_lines lines);
+	int (*redefine_char)(struct charlcd *lcd, char *esc);
 };
 
 void charlcd_backlight(struct charlcd *lcd, enum charlcd_onoff on);
diff --git a/drivers/auxdisplay/hd44780.c b/drivers/auxdisplay/hd44780.c
index 7b7b28d72198..2e5e7c993933 100644
--- a/drivers/auxdisplay/hd44780.c
+++ b/drivers/auxdisplay/hd44780.c
@@ -138,6 +138,7 @@ static const struct charlcd_ops hd44780_ops_gpio8 = {
 	.blink		= hd44780_common_blink,
 	.fontsize	= hd44780_common_fontsize,
 	.lines		= hd44780_common_lines,
+	.redefine_char	= hd44780_common_redefine_char,
 };
 
 /* Send a command to the LCD panel in 4 bit GPIO mode */
@@ -193,6 +194,7 @@ static const struct charlcd_ops hd44780_ops_gpio4 = {
 	.blink		= hd44780_common_blink,
 	.fontsize	= hd44780_common_fontsize,
 	.lines		= hd44780_common_lines,
+	.redefine_char	= hd44780_common_redefine_char,
 };
 
 static int hd44780_probe(struct platform_device *pdev)
diff --git a/drivers/auxdisplay/hd44780_common.c b/drivers/auxdisplay/hd44780_common.c
index 9d538fdcd260..c528fb8e8808 100644
--- a/drivers/auxdisplay/hd44780_common.c
+++ b/drivers/auxdisplay/hd44780_common.c
@@ -26,6 +26,8 @@
 #define LCD_CMD_TWO_LINES	0x08	/* Set to two display lines */
 #define LCD_CMD_FONT_5X10_DOTS	0x04	/* Set char font to 5x10 dots */
 
+#define LCD_CMD_SET_CGRAM_ADDR	0x40	/* Set char generator RAM address */
+
 #define LCD_CMD_SET_DDRAM_ADDR	0x80	/* Set display data RAM address */
 
 /* sleeps that many milliseconds with a reschedule */
@@ -289,6 +291,61 @@ int hd44780_common_lines(struct charlcd *lcd, enum charlcd_lines lines)
 }
 EXPORT_SYMBOL_GPL(hd44780_common_lines);
 
+int hd44780_common_redefine_char(struct charlcd *lcd, char *esc)
+{
+	/* Generator : LGcxxxxx...xx; must have <c> between '0'
+	 * and '7', representing the numerical ASCII code of the
+	 * redefined character, and <xx...xx> a sequence of 16
+	 * hex digits representing 8 bytes for each character.
+	 * Most LCDs will only use 5 lower bits of the 7 first
+	 * bytes.
+	 */
+
+	struct hd44780_common *hdc = lcd->drvdata;
+	unsigned char cgbytes[8];
+	unsigned char cgaddr;
+	int cgoffset;
+	int shift;
+	char value;
+	int addr;
+
+	if (!strchr(esc, ';'))
+		return 0;
+
+	esc++;
+
+	cgaddr = *(esc++) - '0';
+	if (cgaddr > 7)
+		return 1;
+
+	cgoffset = 0;
+	shift = 0;
+	value = 0;
+	while (*esc && cgoffset < 8) {
+		int half;
+
+		shift ^= 4;
+		half = hex_to_bin(*esc++);
+		if (half < 0)
+			continue;
+
+		value |= half << shift;
+		if (shift == 0) {
+			cgbytes[cgoffset++] = value;
+			value = 0;
+		}
+	}
+
+	hdc->write_cmd(hdc, LCD_CMD_SET_CGRAM_ADDR | (cgaddr * 8));
+	for (addr = 0; addr < cgoffset; addr++)
+		hdc->write_data(hdc, cgbytes[addr]);
+
+	/* ensures that we stop writing to CGRAM */
+	lcd->ops->gotoxy(lcd);
+	return 1;
+}
+EXPORT_SYMBOL_GPL(hd44780_common_redefine_char);
+
 struct hd44780_common *hd44780_common_alloc(void)
 {
 	struct hd44780_common *hd;
diff --git a/drivers/auxdisplay/hd44780_common.h b/drivers/auxdisplay/hd44780_common.h
index e5a69fdc3b61..bc817d1610d4 100644
--- a/drivers/auxdisplay/hd44780_common.h
+++ b/drivers/auxdisplay/hd44780_common.h
@@ -29,4 +29,5 @@ int hd44780_common_cursor(struct charlcd *lcd, enum charlcd_onoff on);
 int hd44780_common_blink(struct charlcd *lcd, enum charlcd_onoff on);
 int hd44780_common_fontsize(struct charlcd *lcd, enum charlcd_fontsize size);
 int hd44780_common_lines(struct charlcd *lcd, enum charlcd_lines lines);
+int hd44780_common_redefine_char(struct charlcd *lcd, char *esc);
 struct hd44780_common *hd44780_common_alloc(void);
diff --git a/drivers/auxdisplay/panel.c b/drivers/auxdisplay/panel.c
index 3d33d7cc979c..b0d2ae5b9be8 100644
--- a/drivers/auxdisplay/panel.c
+++ b/drivers/auxdisplay/panel.c
@@ -886,6 +886,7 @@ static const struct charlcd_ops charlcd_serial_ops = {
 	.blink		= hd44780_common_blink,
 	.fontsize	= hd44780_common_fontsize,
 	.lines		= hd44780_common_lines,
+	.redefine_char	= hd44780_common_redefine_char,
 };
 
 static const struct charlcd_ops charlcd_parallel_ops = {
@@ -902,6 +903,7 @@ static const struct charlcd_ops charlcd_parallel_ops = {
 	.blink		= hd44780_common_blink,
 	.fontsize	= hd44780_common_fontsize,
 	.lines		= hd44780_common_lines,
+	.redefine_char	= hd44780_common_redefine_char,
 };
 
 static const struct charlcd_ops charlcd_tilcd_ops = {
@@ -918,6 +920,7 @@ static const struct charlcd_ops charlcd_tilcd_ops = {
 	.blink		= hd44780_common_blink,
 	.fontsize	= hd44780_common_fontsize,
 	.lines		= hd44780_common_lines,
+	.redefine_char	= hd44780_common_redefine_char,
 };
 
 /* initialize the LCD driver */
-- 
2.28.0

[PATCH v5 18/25] auxdisplay: Call charlcd_backlight in place

[poeschel]

From: Lars Poeschel <poeschel@lemonage.de>

This moves the call to charlcd_backlight from the end of the switch
into the actual case statement that originates the change of the
backlight. This is more consistent to what is now found in this switch.

Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
 drivers/auxdisplay/charlcd.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index dca1b138a239..0f0568a4bd35 100644
--- a/drivers/auxdisplay/charlcd.c
+++ b/drivers/auxdisplay/charlcd.c
@@ -259,10 +259,16 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 		break;
 	case '+':	/* Back light ON */
 		priv->flags |= LCD_FLAG_L;
+		if (priv->flags != oldflags)
+			charlcd_backlight(lcd, CHARLCD_ON);
+
 		processed = 1;
 		break;
 	case '-':	/* Back light OFF */
 		priv->flags &= ~LCD_FLAG_L;
+		if (priv->flags != oldflags)
+			charlcd_backlight(lcd, CHARLCD_OFF);
+
 		processed = 1;
 		break;
 	case '*':	/* Flash back light */
@@ -363,14 +369,6 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 		break;
 	}
 
-	/* TODO: This indent party here got ugly, clean it! */
-	/* Check whether one flag was changed */
-	if (oldflags == priv->flags)
-		return processed;
-
-	if ((oldflags ^ priv->flags) & LCD_FLAG_L)
-		charlcd_backlight(lcd, !!(priv->flags & LCD_FLAG_L));
-
 	return processed;
 }
 
-- 
2.28.0

[PATCH v5 19/25] auxdisplay: hd44780_common: Reduce clear_display timeout

[poeschel]

From: Lars Poeschel <poeschel@lemonage.de>

Digging in the hd44780 datasheet revealed that the timeout needed after
clearing the whole display is only 1,64ms not 15ms. So we can reduce
that timeout.

Link: https://lore.kernel.org/lkml/20200922092121.GG16421@1wt.eu/
Link: https://www.crystalfontz.com/controllers/Hitachi/HD44780/433/

Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
Changes in v3:
- This patch is new in v3
---
 drivers/auxdisplay/hd44780_common.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/auxdisplay/hd44780_common.c b/drivers/auxdisplay/hd44780_common.c
index c528fb8e8808..bd93a4d3367e 100644
--- a/drivers/auxdisplay/hd44780_common.c
+++ b/drivers/auxdisplay/hd44780_common.c
@@ -83,8 +83,8 @@ int hd44780_common_clear_display(struct charlcd *lcd)
 	struct hd44780_common *hdc = lcd->drvdata;
 
 	hdc->write_cmd(hdc, LCD_CMD_DISPLAY_CLEAR);
-	/* we must wait a few milliseconds (15) */
-	long_sleep(15);
+	/* datasheet says to wait 1,64 milliseconds */
+	long_sleep(2);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(hd44780_common_clear_display);
-- 
2.28.0

[PATCH v5 20/25] auxdisplay: hd44780: Remove clear_fast

[poeschel]

From: Lars Poeschel <poeschel@lemonage.de>

We remove the hd44780_clear_fast (display) clear implementation. With
the new timeout the normal clear_display is reasonably fast. So there is
no need for a clear_fast anymore.

Link: https://lore.kernel.org/lkml/20200922092121.GG16421@1wt.eu/

Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
Changes in v3:
- This patch is squashed together from 26, 27 and 28 from previous patch
  set:
Link: https://lore.kernel.org/lkml/20200921144645.2061313-27-poeschel@lemonage.de/
Link: https://lore.kernel.org/lkml/20200921144645.2061313-28-poeschel@lemonage.de/
Link: https://lore.kernel.org/lkml/20200921144645.2061313-29-poeschel@lemonage.de/

- Additionally this now removes clear_fast from charlcd_ops and from
  panel driver.
---
 drivers/auxdisplay/charlcd.c | 21 ++++-------
 drivers/auxdisplay/charlcd.h |  7 ++--
 drivers/auxdisplay/panel.c   | 67 ------------------------------------
 3 files changed, 8 insertions(+), 87 deletions(-)

diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index 0f0568a4bd35..077c01e87127 100644
--- a/drivers/auxdisplay/charlcd.c
+++ b/drivers/auxdisplay/charlcd.c
@@ -125,20 +125,11 @@ static void charlcd_print(struct charlcd *lcd, char c)
 		lcd->ops->gotoxy(lcd);
 }
 
-static void charlcd_clear_fast(struct charlcd *lcd)
+static void charlcd_clear_display(struct charlcd *lcd)
 {
-	struct hd44780_common *hdc = lcd->drvdata;
-	int pos;
-
-	charlcd_home(lcd);
-
-	if (lcd->ops->clear_fast)
-		lcd->ops->clear_fast(lcd);
-	else
-		for (pos = 0; pos < min(2, lcd->height) * hdc->hwidth; pos++)
-			lcd->ops->print(lcd, ' ');
-
-	charlcd_home(lcd);
+	lcd->ops->clear_display(lcd);
+	lcd->addr.x = 0;
+	lcd->addr.y = 0;
 }
 
 /*
@@ -409,7 +400,7 @@ static void charlcd_write_char(struct charlcd *lcd, char c)
 			break;
 		case '\f':
 			/* quickly clear the display */
-			charlcd_clear_fast(lcd);
+			charlcd_clear_display(lcd);
 			break;
 		case '\n':
 			/*
@@ -448,7 +439,7 @@ static void charlcd_write_char(struct charlcd *lcd, char c)
 
 		if (!strcmp(priv->esc_seq.buf, "[2J")) {
 			/* clear the display */
-			charlcd_clear_fast(lcd);
+			charlcd_clear_display(lcd);
 			processed = 1;
 		} else if (!strcmp(priv->esc_seq.buf, "[H")) {
 			/* cursor to home */
diff --git a/drivers/auxdisplay/charlcd.h b/drivers/auxdisplay/charlcd.h
index 3339e8c2554e..e7e9b12b1e99 100644
--- a/drivers/auxdisplay/charlcd.h
+++ b/drivers/auxdisplay/charlcd.h
@@ -55,8 +55,6 @@ struct charlcd {
 /**
  * struct charlcd_ops - Functions used by charlcd. Drivers have to implement
  * these.
- * @clear_fast: Clear the whole display and set cursor to position 0, 0.
- * Optional.
  * @backlight: Turn backlight on or off. Optional.
  * @print: Print one character to the display at current cursor position.
  * The buffered cursor position is advanced by charlcd. The cursor should not
@@ -65,8 +63,8 @@ struct charlcd {
  * previously set in addr.x and addr.y by charlcd.
  * @home: Set cursor to 0, 0. The values in addr.x and addr.y are set to 0, 0 by
  * charlcd prior to calling this function.
- * @clear_display: Again clear the whole display, set the cursor to 0, 0. The
- * values in addr.x and addr.y are set to 0, 0 by charlcd prior to calling this
+ * @clear_display: Clear the whole display and set the cursor to 0, 0. The
+ * values in addr.x and addr.y are set to 0, 0 by charlcd after to calling this
  * function.
  * @init_display: Initialize the display.
  * @shift_cursor: Shift cursor left or right one position.
@@ -78,7 +76,6 @@ struct charlcd {
  * @redefine_char: Redefine the actual pixel matrix of character.
  */
 struct charlcd_ops {
-	void (*clear_fast)(struct charlcd *lcd);
 	void (*backlight)(struct charlcd *lcd, enum charlcd_onoff on);
 	int (*print)(struct charlcd *lcd, int c);
 	int (*gotoxy)(struct charlcd *lcd);
diff --git a/drivers/auxdisplay/panel.c b/drivers/auxdisplay/panel.c
index b0d2ae5b9be8..e07fadac281d 100644
--- a/drivers/auxdisplay/panel.c
+++ b/drivers/auxdisplay/panel.c
@@ -808,72 +808,7 @@ static void lcd_write_data_tilcd(struct hd44780_common *hdc, int data)
 	spin_unlock_irq(&pprt_lock);
 }
 
-/* fills the display with spaces and resets X/Y */
-static void lcd_clear_fast_s(struct charlcd *charlcd)
-{
-	struct hd44780_common *hdc = charlcd->drvdata;
-	int pos;
-
-	spin_lock_irq(&pprt_lock);
-	for (pos = 0; pos < charlcd->height * hdc->hwidth; pos++) {
-		lcd_send_serial(0x5F);	/* R/W=W, RS=1 */
-		lcd_send_serial(' ' & 0x0F);
-		lcd_send_serial((' ' >> 4) & 0x0F);
-		/* the shortest data takes at least 40 us */
-		udelay(40);
-	}
-	spin_unlock_irq(&pprt_lock);
-}
-
-/* fills the display with spaces and resets X/Y */
-static void lcd_clear_fast_p8(struct charlcd *charlcd)
-{
-	struct hd44780_common *hdc = charlcd->drvdata;
-	int pos;
-
-	spin_lock_irq(&pprt_lock);
-	for (pos = 0; pos < charlcd->height * hdc->hwidth; pos++) {
-		/* present the data to the data port */
-		w_dtr(pprt, ' ');
-
-		/* maintain the data during 20 us before the strobe */
-		udelay(20);
-
-		set_bit(LCD_BIT_E, bits);
-		set_bit(LCD_BIT_RS, bits);
-		clear_bit(LCD_BIT_RW, bits);
-		set_ctrl_bits();
-
-		/* maintain the strobe during 40 us */
-		udelay(40);
-
-		clear_bit(LCD_BIT_E, bits);
-		set_ctrl_bits();
-
-		/* the shortest data takes at least 45 us */
-		udelay(45);
-	}
-	spin_unlock_irq(&pprt_lock);
-}
-
-/* fills the display with spaces and resets X/Y */
-static void lcd_clear_fast_tilcd(struct charlcd *charlcd)
-{
-	struct hd44780_common *hdc = charlcd->drvdata;
-	int pos;
-
-	spin_lock_irq(&pprt_lock);
-	for (pos = 0; pos < charlcd->height * hdc->hwidth; pos++) {
-		/* present the data to the data port */
-		w_dtr(pprt, ' ');
-		udelay(60);
-	}
-
-	spin_unlock_irq(&pprt_lock);
-}
-
 static const struct charlcd_ops charlcd_serial_ops = {
-	.clear_fast	= lcd_clear_fast_s,
 	.backlight	= lcd_backlight,
 	.gotoxy		= hd44780_common_gotoxy,
 	.home		= hd44780_common_home,
@@ -890,7 +825,6 @@ static const struct charlcd_ops charlcd_serial_ops = {
 };
 
 static const struct charlcd_ops charlcd_parallel_ops = {
-	.clear_fast	= lcd_clear_fast_p8,
 	.backlight	= lcd_backlight,
 	.gotoxy		= hd44780_common_gotoxy,
 	.home		= hd44780_common_home,
@@ -907,7 +841,6 @@ static const struct charlcd_ops charlcd_parallel_ops = {
 };
 
 static const struct charlcd_ops charlcd_tilcd_ops = {
-	.clear_fast	= lcd_clear_fast_tilcd,
 	.backlight	= lcd_backlight,
 	.gotoxy		= hd44780_common_gotoxy,
 	.home		= hd44780_common_home,
-- 
2.28.0

[PATCH v5 21/25] auxdisplay: charlcd: replace last device specific stuff

[poeschel]

From: Lars Poeschel <poeschel@lemonage.de>

These are the last bits left in charlcd.c that are device specific and
they are removed now.
In detail this is:
* bwidth, which is the width of the display buffer per line. This is
  replaced by width of the display.
* hwidth, which is the size of the display buffer as a whole. This is
  replaced by looping all chars of a line by all lines.
* the hd44780_common header include can go away.

Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
 drivers/auxdisplay/charlcd.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index 077c01e87127..59f21401d6a9 100644
--- a/drivers/auxdisplay/charlcd.c
+++ b/drivers/auxdisplay/charlcd.c
@@ -20,7 +20,6 @@
 #include <generated/utsrelease.h>
 
 #include "charlcd.h"
-#include "hd44780_common.h"
 
 /* Keep the backlight on this many seconds for each flash */
 #define LCD_BL_TEMPO_PERIOD	4
@@ -112,8 +111,6 @@ static void charlcd_home(struct charlcd *lcd)
 
 static void charlcd_print(struct charlcd *lcd, char c)
 {
-	struct hd44780_common *hdc = lcd->drvdata;
-
 	if (lcd->char_conv)
 		c = lcd->char_conv[(unsigned char)c];
 
@@ -121,7 +118,7 @@ static void charlcd_print(struct charlcd *lcd, char c)
 		lcd->addr.x++;
 
 	/* prevents the cursor from wrapping onto the next line */
-	if (lcd->addr.x == hdc->bwidth)
+	if (lcd->addr.x == lcd->width)
 		lcd->ops->gotoxy(lcd);
 }
 
@@ -195,7 +192,6 @@ static bool parse_xy(const char *s, unsigned long *x, unsigned long *y)
 static inline int handle_lcd_special_code(struct charlcd *lcd)
 {
 	struct charlcd_priv *priv = charlcd_to_priv(lcd);
-	struct hd44780_common *hdc = lcd->drvdata;
 
 	/* LCD special codes */
 
@@ -323,7 +319,7 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 
 		xs = lcd->addr.x;
 		ys = lcd->addr.y;
-		for (x = lcd->addr.x; x < hdc->bwidth; x++)
+		for (x = lcd->addr.x; x < lcd->width; x++)
 			lcd->ops->print(lcd, ' ');
 
 		/* restore cursor position */
@@ -366,7 +362,6 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 static void charlcd_write_char(struct charlcd *lcd, char c)
 {
 	struct charlcd_priv *priv = charlcd_to_priv(lcd);
-	struct hd44780_common *hdc = lcd->drvdata;
 
 	/* first, we'll test if we're in escape mode */
 	if ((c != '\n') && priv->esc_seq.len >= 0) {
@@ -407,7 +402,7 @@ static void charlcd_write_char(struct charlcd *lcd, char c)
 			 * flush the remainder of the current line and
 			 * go to the beginning of the next line
 			 */
-			for (; lcd->addr.x < hdc->bwidth; lcd->addr.x++)
+			for (; lcd->addr.x < lcd->width; lcd->addr.x++)
 				lcd->ops->print(lcd, ' ');
 
 			lcd->addr.x = 0;
-- 
2.28.0

[PATCH v5 22/25] auxdisplay: Change gotoxy calling interface

[poeschel]

From: Lars Poeschel <poeschel@lemonage.de>

Change the calling interface for gotoxy from supplying the x and y
coordinates in the charlcd struct to explicitly supplying x and y in
the function arguments. This is more intuitive and allows for moving
the cursor to positions independent from the position saved in the
charlcd struct.

Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
 drivers/auxdisplay/charlcd.c        | 10 +++++-----
 drivers/auxdisplay/charlcd.h        |  2 +-
 drivers/auxdisplay/hd44780_common.c | 15 ++++++---------
 drivers/auxdisplay/hd44780_common.h |  2 +-
 4 files changed, 13 insertions(+), 16 deletions(-)

diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index 59f21401d6a9..ef10b5ca0e16 100644
--- a/drivers/auxdisplay/charlcd.c
+++ b/drivers/auxdisplay/charlcd.c
@@ -119,7 +119,7 @@ static void charlcd_print(struct charlcd *lcd, char c)
 
 	/* prevents the cursor from wrapping onto the next line */
 	if (lcd->addr.x == lcd->width)
-		lcd->ops->gotoxy(lcd);
+		lcd->ops->gotoxy(lcd, lcd->addr.x - 1, lcd->addr.y);
 }
 
 static void charlcd_clear_display(struct charlcd *lcd)
@@ -325,7 +325,7 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 		/* restore cursor position */
 		lcd->addr.x = xs;
 		lcd->addr.y = ys;
-		lcd->ops->gotoxy(lcd);
+		lcd->ops->gotoxy(lcd, lcd->addr.x, lcd->addr.y);
 		processed = 1;
 		break;
 	}
@@ -349,7 +349,7 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 
 		/* If the command is valid, move to the new address */
 		if (parse_xy(esc, &lcd->addr.x, &lcd->addr.y))
-			lcd->ops->gotoxy(lcd);
+			lcd->ops->gotoxy(lcd, lcd->addr.x, lcd->addr.y);
 
 		/* Regardless of its validity, mark as processed */
 		processed = 1;
@@ -407,12 +407,12 @@ static void charlcd_write_char(struct charlcd *lcd, char c)
 
 			lcd->addr.x = 0;
 			lcd->addr.y = (lcd->addr.y + 1) % lcd->height;
-			lcd->ops->gotoxy(lcd);
+			lcd->ops->gotoxy(lcd, lcd->addr.x, lcd->addr.y);
 			break;
 		case '\r':
 			/* go to the beginning of the same line */
 			lcd->addr.x = 0;
-			lcd->ops->gotoxy(lcd);
+			lcd->ops->gotoxy(lcd, lcd->addr.x, lcd->addr.y);
 			break;
 		case '\t':
 			/* print a space instead of the tab */
diff --git a/drivers/auxdisplay/charlcd.h b/drivers/auxdisplay/charlcd.h
index e7e9b12b1e99..eed80063a6d2 100644
--- a/drivers/auxdisplay/charlcd.h
+++ b/drivers/auxdisplay/charlcd.h
@@ -78,7 +78,7 @@ struct charlcd {
 struct charlcd_ops {
 	void (*backlight)(struct charlcd *lcd, enum charlcd_onoff on);
 	int (*print)(struct charlcd *lcd, int c);
-	int (*gotoxy)(struct charlcd *lcd);
+	int (*gotoxy)(struct charlcd *lcd, unsigned int x, unsigned int y);
 	int (*home)(struct charlcd *lcd);
 	int (*clear_display)(struct charlcd *lcd);
 	int (*init_display)(struct charlcd *lcd);
diff --git a/drivers/auxdisplay/hd44780_common.c b/drivers/auxdisplay/hd44780_common.c
index bd93a4d3367e..3934c2eebf33 100644
--- a/drivers/auxdisplay/hd44780_common.c
+++ b/drivers/auxdisplay/hd44780_common.c
@@ -49,7 +49,7 @@ int hd44780_common_print(struct charlcd *lcd, int c)
 }
 EXPORT_SYMBOL_GPL(hd44780_common_print);
 
-int hd44780_common_gotoxy(struct charlcd *lcd)
+int hd44780_common_gotoxy(struct charlcd *lcd, unsigned int x, unsigned int y)
 {
 	struct hd44780_common *hdc = lcd->drvdata;
 	unsigned int addr;
@@ -58,11 +58,10 @@ int hd44780_common_gotoxy(struct charlcd *lcd)
 	 * we force the cursor to stay at the end of the
 	 * line if it wants to go farther
 	 */
-	addr = lcd->addr.x < hdc->bwidth ? lcd->addr.x & (hdc->hwidth - 1)
-					  : hdc->bwidth - 1;
-	if (lcd->addr.y & 1)
+	addr = x < hdc->bwidth ? x & (hdc->hwidth - 1) : hdc->bwidth - 1;
+	if (y & 1)
 		addr += hdc->hwidth;
-	if (lcd->addr.y & 2)
+	if (y & 2)
 		addr += hdc->bwidth;
 	hdc->write_cmd(hdc, LCD_CMD_SET_DDRAM_ADDR | addr);
 	return 0;
@@ -71,9 +70,7 @@ EXPORT_SYMBOL_GPL(hd44780_common_gotoxy);
 
 int hd44780_common_home(struct charlcd *lcd)
 {
-	lcd->addr.x = 0;
-	lcd->addr.y = 0;
-	return hd44780_common_gotoxy(lcd);
+	return hd44780_common_gotoxy(lcd, 0, 0);
 }
 EXPORT_SYMBOL_GPL(hd44780_common_home);
 
@@ -341,7 +338,7 @@ int hd44780_common_redefine_char(struct charlcd *lcd, char *esc)
 		hdc->write_data(hdc, cgbytes[addr]);
 
 	/* ensures that we stop writing to CGRAM */
-	lcd->ops->gotoxy(lcd);
+	lcd->ops->gotoxy(lcd, lcd->addr.x, lcd->addr.y);
 	return 1;
 }
 EXPORT_SYMBOL_GPL(hd44780_common_redefine_char);
diff --git a/drivers/auxdisplay/hd44780_common.h b/drivers/auxdisplay/hd44780_common.h
index bc817d1610d4..a16aa8c29c99 100644
--- a/drivers/auxdisplay/hd44780_common.h
+++ b/drivers/auxdisplay/hd44780_common.h
@@ -16,7 +16,7 @@ struct hd44780_common {
 };
 
 int hd44780_common_print(struct charlcd *lcd, int c);
-int hd44780_common_gotoxy(struct charlcd *lcd);
+int hd44780_common_gotoxy(struct charlcd *lcd, unsigned int x, unsigned int y);
 int hd44780_common_home(struct charlcd *lcd);
 int hd44780_common_clear_display(struct charlcd *lcd);
 int hd44780_common_init_display(struct charlcd *lcd);
-- 
2.28.0

[PATCH v5 23/25] auxdisplay: charlcd: Do not print chars at end of line

[poeschel]

From: Lars Poeschel <poeschel@lemonage.de>

Skip printing characters at the end of a display line. This fits to the
behaviour we already had, that the cursor is nailed to last position of
a line.
This might slightly change behaviour.
On hd44780 displays with one or two lines the previous implementation
did still write characters to the buffer of the display even if they are
currently not visible. The shift_display command could be used so set
the "viewing window" to a new position in the buffer and then you could
see the characters previously written.
This described behaviour does not work for hd44780 displays with more
than two display lines. There simply is not enough buffer.
So the behaviour was a bit inconsistens across different displays.
The new behaviour is to stop writing character at the end of a visible
line, even if there would be room in the buffer. This allows us to have
an easy implementation, that should behave equal on all supported
displays. This is not hd44780 hardware dependents anymore.

Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
Changes in v3:
- Better patch description
---
 drivers/auxdisplay/charlcd.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index ef10b5ca0e16..f43430e9dcee 100644
--- a/drivers/auxdisplay/charlcd.c
+++ b/drivers/auxdisplay/charlcd.c
@@ -111,6 +111,9 @@ static void charlcd_home(struct charlcd *lcd)
 
 static void charlcd_print(struct charlcd *lcd, char c)
 {
+	if (lcd->addr.x >= lcd->width)
+		return;
+
 	if (lcd->char_conv)
 		c = lcd->char_conv[(unsigned char)c];
 
-- 
2.28.0

[PATCH v5 24/25] auxdisplay: lcd2s DT binding doc

[poeschel]

From: Lars Poeschel <poeschel@lemonage.de>

Add a binding doc for the modtronix lcd2s auxdisplay driver. It also
adds modtronix to the list of known vendor-prefixes.

Reviewed-by: Willy Tarreau <w@1wt.eu>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
Changes in v5:
- Picked up Robs Reviewed-by
Changes in v3:
- Fixed make dt_binding_doc errors
Changes in v2:
- Adopted yaml based file format
---
 .../bindings/auxdisplay/modtronix,lcd2s.yaml  | 58 +++++++++++++++++++
 .../devicetree/bindings/vendor-prefixes.yaml  |  2 +
 2 files changed, 60 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/auxdisplay/modtronix,lcd2s.yaml

diff --git a/Documentation/devicetree/bindings/auxdisplay/modtronix,lcd2s.yaml b/Documentation/devicetree/bindings/auxdisplay/modtronix,lcd2s.yaml
new file mode 100644
index 000000000000..a1d55a2634a5
--- /dev/null
+++ b/Documentation/devicetree/bindings/auxdisplay/modtronix,lcd2s.yaml
@@ -0,0 +1,58 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/auxdisplay/modtronix,lcd2s.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Modtronix engineering LCD2S Character LCD Display
+
+maintainers:
+  - Lars Poeschel <poeschel@lemonage.de>
+
+description:
+  The LCD2S is a Character LCD Display manufactured by Modtronix Engineering.
+  The display supports a serial I2C and SPI interface. The driver currently
+  only supports the I2C interface.
+
+properties:
+  compatible:
+    const: modtronix,lcd2s
+
+  reg:
+    maxItems: 1
+    description:
+      I2C bus address of the display.
+
+  display-height-chars:
+    description: Height of the display, in character cells.
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 1
+    maximum: 4
+
+  display-width-chars:
+    description: Width of the display, in character cells.
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 16
+    maximum: 20
+
+required:
+  - compatible
+  - reg
+  - display-height-chars
+  - display-width-chars
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      lcd2s: auxdisplay@28 {
+        compatible = "modtronix,lcd2s";
+        reg = <0x28>;
+        display-height-chars = <4>;
+        display-width-chars = <20>;
+      };
+    };
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.yaml b/Documentation/devicetree/bindings/vendor-prefixes.yaml
index 2735be1a8470..65f40ab5a87f 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.yaml
+++ b/Documentation/devicetree/bindings/vendor-prefixes.yaml
@@ -681,6 +681,8 @@ patternProperties:
     description: MiraMEMS Sensing Technology Co., Ltd.
   "^mitsubishi,.*":
     description: Mitsubishi Electric Corporation
+  "^modtronix,.*":
+    description: Modtronix Engineering
   "^mosaixtech,.*":
     description: Mosaix Technologies, Inc.
   "^motorola,.*":
-- 
2.28.0

[PATCH v5 25/25] auxdisplay: add a driver for lcd2s character display

[poeschel]

From: Lars Poeschel <poeschel@lemonage.de>

This driver allows to use a lcd2s 20x4 character display from Modtronix
engineering as an auxdisplay charlcd device.

Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
Changes in v5:
- use hex_to_bin like in commit 3f03b6498 but for this file
Changes in v4:
- modtronix -> Modtronix
- Kconfig: remove "default n"
---
 drivers/auxdisplay/Kconfig  |  10 +
 drivers/auxdisplay/Makefile |   1 +
 drivers/auxdisplay/lcd2s.c  | 403 ++++++++++++++++++++++++++++++++++++
 3 files changed, 414 insertions(+)
 create mode 100644 drivers/auxdisplay/lcd2s.c

diff --git a/drivers/auxdisplay/Kconfig b/drivers/auxdisplay/Kconfig
index a56171d1a1ba..96c8cdfce48d 100644
--- a/drivers/auxdisplay/Kconfig
+++ b/drivers/auxdisplay/Kconfig
@@ -173,6 +173,16 @@ config HT16K33
 	  Say yes here to add support for Holtek HT16K33, RAM mapping 16*8
 	  LED controller driver with keyscan.
 
+config LCD2S
+	tristate "lcd2s 20x4 character display over I2C console"
+	depends on I2C
+	select CHARLCD
+	help
+	  This is a driver that lets you use the lcd2s 20x4 character display
+	  from Modtronix engineering as a console output device. The display
+	  is a simple single color character display. You have to connect it
+	  to an I2C bus.
+
 config ARM_CHARLCD
 	bool "ARM Ltd. Character LCD Driver"
 	depends on PLAT_VERSATILE
diff --git a/drivers/auxdisplay/Makefile b/drivers/auxdisplay/Makefile
index 7e8a8c3eb3c3..307771027c89 100644
--- a/drivers/auxdisplay/Makefile
+++ b/drivers/auxdisplay/Makefile
@@ -12,3 +12,4 @@ obj-$(CONFIG_IMG_ASCII_LCD)	+= img-ascii-lcd.o
 obj-$(CONFIG_HD44780)		+= hd44780.o
 obj-$(CONFIG_HT16K33)		+= ht16k33.o
 obj-$(CONFIG_PARPORT_PANEL)	+= panel.o
+obj-$(CONFIG_LCD2S)		+= lcd2s.o
diff --git a/drivers/auxdisplay/lcd2s.c b/drivers/auxdisplay/lcd2s.c
new file mode 100644
index 000000000000..cfa5f86deeef
--- /dev/null
+++ b/drivers/auxdisplay/lcd2s.c
@@ -0,0 +1,403 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  console driver for LCD2S 4x20 character displays connected through i2c.
+ *  The display also has a spi interface, but the driver does not support
+ *  this yet.
+ *
+ *  This is a driver allowing you to use a LCD2S 4x20 from modtronix
+ *  engineering as auxdisplay character device.
+ *
+ *  (C) 2019 by Lemonage Software GmbH
+ *  Author: Lars Pöschel <poeschel@lemonage.de>
+ *  All rights reserved.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/delay.h>
+
+#include "charlcd.h"
+
+#define LCD2S_CMD_CUR_MOVES_FWD		0x09
+#define LCD2S_CMD_CUR_BLINK_OFF		0x10
+#define LCD2S_CMD_CUR_UL_OFF		0x11
+#define LCD2S_CMD_DISPLAY_OFF		0x12
+#define LCD2S_CMD_CUR_BLINK_ON		0x18
+#define LCD2S_CMD_CUR_UL_ON		0x19
+#define LCD2S_CMD_DISPLAY_ON		0x1a
+#define LCD2S_CMD_BACKLIGHT_OFF		0x20
+#define LCD2S_CMD_BACKLIGHT_ON		0x28
+#define LCD2S_CMD_WRITE			0x80
+#define LCD2S_CMD_MOV_CUR_RIGHT		0x83
+#define LCD2S_CMD_MOV_CUR_LEFT		0x84
+#define LCD2S_CMD_SHIFT_RIGHT		0x85
+#define LCD2S_CMD_SHIFT_LEFT		0x86
+#define LCD2S_CMD_SHIFT_UP		0x87
+#define LCD2S_CMD_SHIFT_DOWN		0x88
+#define LCD2S_CMD_CUR_ADDR		0x89
+#define LCD2S_CMD_CUR_POS		0x8a
+#define LCD2S_CMD_CUR_RESET		0x8b
+#define LCD2S_CMD_CLEAR			0x8c
+#define LCD2S_CMD_DEF_CUSTOM_CHAR	0x92
+#define LCD2S_CMD_READ_STATUS		0xd0
+
+#define LCD2S_CHARACTER_SIZE		8
+
+#define LCD2S_STATUS_BUF_MASK		0x7f
+
+struct lcd2s_data {
+	struct i2c_client *i2c;
+	struct charlcd *charlcd;
+};
+
+static s32 lcd2s_wait_buf_free(const struct i2c_client *client, int count)
+{
+	s32 status;
+
+	status = i2c_smbus_read_byte_data(client, LCD2S_CMD_READ_STATUS);
+	if (status < 0)
+		return status;
+
+	while ((status & LCD2S_STATUS_BUF_MASK) < count) {
+		mdelay(1);
+		status = i2c_smbus_read_byte_data(client,
+						  LCD2S_CMD_READ_STATUS);
+		if (status < 0)
+			return status;
+	}
+	return 0;
+}
+
+static int lcd2s_i2c_master_send(const struct i2c_client *client,
+				 const char *buf, int count)
+{
+	s32 status;
+
+	status = lcd2s_wait_buf_free(client, count);
+	if (status < 0)
+		return status;
+
+	return i2c_master_send(client, buf, count);
+}
+
+static int lcd2s_i2c_smbus_write_byte(const struct i2c_client *client, u8 value)
+{
+	s32 status;
+
+	status = lcd2s_wait_buf_free(client, 1);
+	if (status < 0)
+		return status;
+
+	return i2c_smbus_write_byte(client, value);
+}
+
+static int lcd2s_print(struct charlcd *lcd, int c)
+{
+	struct lcd2s_data *lcd2s = lcd->drvdata;
+	u8 buf[2] = { LCD2S_CMD_WRITE, c };
+
+	lcd2s_i2c_master_send(lcd2s->i2c, buf, sizeof(buf));
+	return 0;
+}
+
+static int lcd2s_gotoxy(struct charlcd *lcd, unsigned int x, unsigned int y)
+{
+	struct lcd2s_data *lcd2s = lcd->drvdata;
+	u8 buf[] = { LCD2S_CMD_CUR_POS, y + 1, x + 1};
+
+	lcd2s_i2c_master_send(lcd2s->i2c, buf, sizeof(buf));
+
+	return 0;
+}
+
+static int lcd2s_home(struct charlcd *lcd)
+{
+	struct lcd2s_data *lcd2s = lcd->drvdata;
+
+	lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_CUR_RESET);
+	return 0;
+}
+
+static int lcd2s_init_display(struct charlcd *lcd)
+{
+	struct lcd2s_data *lcd2s = lcd->drvdata;
+
+	/* turn everything off, but display on */
+	lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_DISPLAY_ON);
+	lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_BACKLIGHT_OFF);
+	lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_CUR_MOVES_FWD);
+	lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_CUR_BLINK_OFF);
+	lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_CUR_UL_OFF);
+	lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_CLEAR);
+
+	return 0;
+}
+
+static int lcd2s_shift_cursor(struct charlcd *lcd, enum charlcd_shift_dir dir)
+{
+	struct lcd2s_data *lcd2s = lcd->drvdata;
+
+	if (dir == CHARLCD_SHIFT_LEFT)
+		lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_MOV_CUR_LEFT);
+	else
+		lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_MOV_CUR_RIGHT);
+
+	return 0;
+}
+
+static int lcd2s_shift_display(struct charlcd *lcd, enum charlcd_shift_dir dir)
+{
+	struct lcd2s_data *lcd2s = lcd->drvdata;
+
+	if (dir == CHARLCD_SHIFT_LEFT)
+		lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_SHIFT_LEFT);
+	else
+		lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_SHIFT_RIGHT);
+
+	return 0;
+}
+
+static void lcd2s_backlight(struct charlcd *lcd, enum charlcd_onoff on)
+{
+	struct lcd2s_data *lcd2s = lcd->drvdata;
+
+	if (on)
+		lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_BACKLIGHT_ON);
+	else
+		lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_BACKLIGHT_OFF);
+}
+
+static int lcd2s_display(struct charlcd *lcd, enum charlcd_onoff on)
+{
+	struct lcd2s_data *lcd2s = lcd->drvdata;
+
+	if (on)
+		lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_DISPLAY_ON);
+	else
+		lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_DISPLAY_OFF);
+
+	return 0;
+}
+
+static int lcd2s_cursor(struct charlcd *lcd, enum charlcd_onoff on)
+{
+	struct lcd2s_data *lcd2s = lcd->drvdata;
+
+	if (on)
+		lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_CUR_UL_ON);
+	else
+		lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_CUR_UL_OFF);
+
+	return 0;
+}
+
+static int lcd2s_blink(struct charlcd *lcd, enum charlcd_onoff on)
+{
+	struct lcd2s_data *lcd2s = lcd->drvdata;
+
+	if (on)
+		lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_CUR_BLINK_ON);
+	else
+		lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_CUR_BLINK_OFF);
+
+	return 0;
+}
+
+static int lcd2s_fontsize(struct charlcd *lcd, enum charlcd_fontsize size)
+{
+	return 0;
+}
+
+static int lcd2s_lines(struct charlcd *lcd, enum charlcd_lines lines)
+{
+	return 0;
+}
+
+static int lcd2s_redefine_char(struct charlcd *lcd, char *esc)
+{
+	/* Generator : LGcxxxxx...xx; must have <c> between '0'
+	 * and '7', representing the numerical ASCII code of the
+	 * redefined character, and <xx...xx> a sequence of 16
+	 * hex digits representing 8 bytes for each character.
+	 * Most LCDs will only use 5 lower bits of the 7 first
+	 * bytes.
+	 */
+
+	struct lcd2s_data *lcd2s = lcd->drvdata;
+	u8 buf[LCD2S_CHARACTER_SIZE + 2] = { LCD2S_CMD_DEF_CUSTOM_CHAR };
+	u8 value;
+	int shift, i;
+
+	if (!strchr(esc, ';'))
+		return 0;
+
+	esc++;
+
+	buf[1] = *(esc++) - '0';
+	if (buf[1] > 7)
+		return 1;
+
+	i = 0;
+	shift = 0;
+	value = 0;
+	while (*esc && i < LCD2S_CHARACTER_SIZE + 2) {
+		int half;
+
+		shift ^= 4;
+		half = hex_to_bin(*esc++);
+		if (half < 0)
+			continue;
+
+		value |= half << shift;
+		if (shift == 0) {
+			buf[i++] = value;
+			value = 0;
+		}
+	}
+
+	lcd2s_i2c_master_send(lcd2s->i2c, buf, sizeof(buf));
+	return 1;
+}
+
+static int lcd2s_clear_display(struct charlcd *lcd)
+{
+	struct lcd2s_data *lcd2s = lcd->drvdata;
+
+	/* This implicitly sets cursor to first row and column */
+	lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_CLEAR);
+	return 0;
+}
+
+static const struct charlcd_ops lcd2s_ops = {
+	.print		= lcd2s_print,
+	.backlight	= lcd2s_backlight,
+	.gotoxy		= lcd2s_gotoxy,
+	.home		= lcd2s_home,
+	.clear_display	= lcd2s_clear_display,
+	.init_display	= lcd2s_init_display,
+	.shift_cursor	= lcd2s_shift_cursor,
+	.shift_display	= lcd2s_shift_display,
+	.display	= lcd2s_display,
+	.cursor		= lcd2s_cursor,
+	.blink		= lcd2s_blink,
+	.fontsize	= lcd2s_fontsize,
+	.lines		= lcd2s_lines,
+	.redefine_char	= lcd2s_redefine_char,
+};
+
+static int lcd2s_i2c_probe(struct i2c_client *i2c,
+				const struct i2c_device_id *id)
+{
+	struct charlcd *lcd;
+	struct lcd2s_data *lcd2s;
+	int err;
+
+	if (!i2c_check_functionality(i2c->adapter,
+			I2C_FUNC_SMBUS_WRITE_BYTE_DATA |
+			I2C_FUNC_SMBUS_WRITE_BLOCK_DATA))
+		return -EIO;
+
+	/* Test, if the display is responding */
+	err = lcd2s_i2c_smbus_write_byte(i2c, LCD2S_CMD_DISPLAY_OFF);
+	if (err < 0)
+		return err;
+
+	lcd = charlcd_alloc();
+	if (!lcd)
+		return -ENOMEM;
+
+	lcd2s = kzalloc(sizeof(struct lcd2s_data), GFP_KERNEL);
+	if (!lcd2s) {
+		err = -ENOMEM;
+		goto fail1;
+	}
+
+	lcd->drvdata = lcd2s;
+	lcd2s->i2c = i2c;
+	lcd2s->charlcd = lcd;
+
+	/* Required properties */
+	err = device_property_read_u32(&i2c->dev, "display-height-chars",
+			&lcd->height);
+	if (err)
+		goto fail2;
+
+	err = device_property_read_u32(&i2c->dev, "display-width-chars",
+			&lcd->width);
+	if (err)
+		goto fail2;
+
+	lcd->ops = &lcd2s_ops;
+
+	err = charlcd_register(lcd2s->charlcd);
+	if (err)
+		goto fail2;
+
+	i2c_set_clientdata(i2c, lcd2s);
+	return 0;
+
+fail2:
+	kfree(lcd2s);
+fail1:
+	kfree(lcd);
+	return err;
+}
+
+static int lcd2s_i2c_remove(struct i2c_client *i2c)
+{
+	struct lcd2s_data *lcd2s = i2c_get_clientdata(i2c);
+
+	kfree(lcd2s->charlcd);
+	charlcd_unregister(lcd2s->charlcd);
+	return 0;
+}
+
+static const struct i2c_device_id lcd2s_i2c_id[] = {
+	{ "lcd2s", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, lcd2s_i2c_id);
+
+#ifdef CONFIG_OF
+static const struct of_device_id lcd2s_of_table[] = {
+	{ .compatible = "modtronix,lcd2s" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, lcd2s_of_table);
+#endif
+
+static struct i2c_driver lcd2s_i2c_driver = {
+	.driver = {
+		.name = "lcd2s",
+		.owner = THIS_MODULE,
+#ifdef CONFIG_OF
+		.of_match_table = of_match_ptr(lcd2s_of_table),
+#endif
+	},
+	.probe = lcd2s_i2c_probe,
+	.remove = lcd2s_i2c_remove,
+	.id_table = lcd2s_i2c_id,
+};
+
+static int __init lcd2s_modinit(void)
+{
+	int ret = 0;
+
+	ret = i2c_add_driver(&lcd2s_i2c_driver);
+	if (ret != 0)
+		pr_err("Failed to register lcd2s driver\n");
+
+	return ret;
+}
+module_init(lcd2s_modinit)
+
+static void __exit lcd2s_exit(void)
+{
+	i2c_del_driver(&lcd2s_i2c_driver);
+}
+module_exit(lcd2s_exit)
+
+MODULE_DESCRIPTION("LCD2S character display driver");
+MODULE_AUTHOR("Lars Poeschel");
+MODULE_LICENSE("GPL");
-- 
2.28.0

Re: [PATCH v5 23/25] auxdisplay: charlcd: Do not print chars at end of line

[Miguel Ojeda]

Hi Lars,

A few extra typos in this commit message.

On Thu, Oct 29, 2020 at 10:58 AM <poeschel@lemonage.de> wrote:
>
> Skip printing characters at the end of a display line. This fits to the
> behaviour we already had, that the cursor is nailed to last position of

to last -> to the last

> a line.
> This might slightly change behaviour.
> On hd44780 displays with one or two lines the previous implementation
> did still write characters to the buffer of the display even if they are
> currently not visible. The shift_display command could be used so set

so -> to

> the "viewing window" to a new position in the buffer and then you could
> see the characters previously written.
> This described behaviour does not work for hd44780 displays with more
> than two display lines. There simply is not enough buffer.
> So the behaviour was a bit inconsistens across different displays.

inconsistent -> inconsistent

> The new behaviour is to stop writing character at the end of a visible

character -> characters

> line, even if there would be room in the buffer. This allows us to have
> an easy implementation, that should behave equal on all supported
> displays. This is not hd44780 hardware dependents anymore.

dependents -> dependent

Cheers,
Miguel

Re: [PATCH v5 02/25] auxdisplay: Introduce hd44780_common.[ch]

[Miguel Ojeda]

Hi Lars,

On Thu, Oct 29, 2020 at 10:57 AM <poeschel@lemonage.de> wrote:
>
> diff --git a/drivers/auxdisplay/Kconfig b/drivers/auxdisplay/Kconfig
> index 81757eeded68..a56171d1a1ba 100644
> --- a/drivers/auxdisplay/Kconfig
> +++ b/drivers/auxdisplay/Kconfig
> @@ -14,12 +14,31 @@ menuconfig AUXDISPLAY
>
>           If you say N, all options in this submenu will be skipped and disabled.
>
> +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.
> +
>  if AUXDISPLAY
>

These two should be after `if AUXDISPLAY`, no? I noticed the menu is
broken when I went to compile test this (the options appear outside
and the auxdisplay menu is empty). Perhaps you don't use menuconfig so
you didn't see it?

Sorry I missed this in previous iterations...

Cheers,
Miguel

Re: [PATCH 00/25] Make charlcd device independent

[Miguel Ojeda]

Hi Lars,

On Thu, Oct 29, 2020 at 10:52 AM <poeschel@lemonage.de> wrote:
>
> Changes in v5:
> - patch 1: Fix a commit message typo: of -> on
> - patch 2: Remove some unnecessary newlines
> - patch 8: Fix some typos
> - patch 14: Fix commit message typo: it's -> its
> - patch 15: this patch is squashed together from the former individual
>   hd44780_common_ function patches
> - patch 16: combined two cleanup patches
> - patch 17: I did previously undo commit 3f03b6498 which was a mistake.
>   This is now corrected.
> - patch 24: Picked up Robs Reviewed-by
> - patch 25: use hex_to_bin like in commit 3f03b6498 but for the lcd2s.c
>   file

Thanks a lot for all that! Please take a look at my other two messages
for v5. We are almost there...

Cheers,
Miguel

Re: [PATCH v5 02/25] auxdisplay: Introduce hd44780_common.[ch]

[Lars Poeschel]

On Sat, Oct 31, 2020 at 10:26:30AM +0100, Miguel Ojeda wrote:
> Hi Lars,
> 
> On Thu, Oct 29, 2020 at 10:57 AM <poeschel@lemonage.de> wrote:
> >
> > diff --git a/drivers/auxdisplay/Kconfig b/drivers/auxdisplay/Kconfig
> > index 81757eeded68..a56171d1a1ba 100644
> > --- a/drivers/auxdisplay/Kconfig
> > +++ b/drivers/auxdisplay/Kconfig
> > @@ -14,12 +14,31 @@ menuconfig AUXDISPLAY
> >
> >           If you say N, all options in this submenu will be skipped and disabled.
> >
> > +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.
> > +
> >  if AUXDISPLAY
> >
> 
> These two should be after `if AUXDISPLAY`, no? I noticed the menu is
> broken when I went to compile test this (the options appear outside
> and the auxdisplay menu is empty). Perhaps you don't use menuconfig so
> you didn't see it?

I did see it and had a look and did not spot anything obvious (to me).
So I put this aside as "This is supposed to be this way."

> Sorry I missed this in previous iterations...

No need to be sorry. In the end it's my fault. I fix this.

Regards,
Lars