[PATCH 2.6.19-rc1 update4] drivers: add LCD support

[PATCH 2.6.19-rc1 update4] drivers: add LCD support

[Miguel Ojeda Sandonis]

Andrew, here it is a small update for the
drivers-add-lcd-support patch at -mm2. Please apply.

Franck Bui-Huu, thanks for pointing out the lack of mmaping support.
---

 - Adds mmaping support for the cfag12864bfb.
 - Exchange the wiring drawing URL to a local ASCII drawing
   at Documentation/auxdisplay/cfag12864b.

 Documentation/auxdisplay/cfag12864b |   37 +++++++++++++++++++++-----
 drivers/auxdisplay/Kconfig          |    7 ----
 drivers/auxdisplay/cfag12864b.c     |   22 +++++++++------
 drivers/auxdisplay/cfag12864bfb.c   |   37 +++++++++++++++++++++++---
 4 files changed, 80 insertions(+), 23 deletions(-)

miguelojeda-2.6.19-rc1-drivers-add-LCD-support-4-mmaping-and-ascii-drawing.patch
Signed-off-by: Miguel Ojeda Sandonis <maxextreme@gmail.com>
---
diff -uprN -X dontdiff linux-2.6.19-rc1-modified/Documentation/auxdisplay/cfag12864b linux/Documentation/auxdisplay/cfag12864b
--- linux-2.6.19-rc1-modified/Documentation/auxdisplay/cfag12864b	2006-10-26 16:57:38.000000000 +0000
+++ linux/Documentation/auxdisplay/cfag12864b	2006-10-26 16:38:54.000000000 +0000
@@ -4,7 +4,7 @@
 
 License:		GPLv2
 Author & Maintainer:	Miguel Ojeda Sandonis <maxextreme@gmail.com>
-Date:			2006-10-11
+Date:			2006-10-26
 
 
 
@@ -51,12 +51,37 @@ Addresses:	64 each page
 
 The cfag12864b LCD Series don't have official wiring.
 
-The common wiring is done to the parallel port:
-
-http://www.skippari.net/lcd/sekalaista/crystalfontz_cfag12864B-TMI-V.png
-
-You can get help at Crystalfontz and LCDInfo forums.
+The common wiring is done to the parallel port as shown:
 
+Parallel Port                          cfag12864b
+
+  Name Pin#                            Pin# Name
+
+Strobe ( 1)------------------------------(17) Enable
+Data 0 ( 2)------------------------------( 4) Data 0
+Data 1 ( 3)------------------------------( 5) Data 1
+Data 2 ( 4)------------------------------( 6) Data 2
+Data 3 ( 5)------------------------------( 7) Data 3
+Data 4 ( 6)------------------------------( 8) Data 4
+Data 5 ( 7)------------------------------( 9) Data 5
+Data 6 ( 8)------------------------------(10) Data 6
+Data 7 ( 9)------------------------------(11) Data 7
+       (10)                      [+5v]---( 1) Vdd
+       (11)                      [GND]---( 2) Ground
+       (12)                      [+5v]---(14) Reset
+       (13)                      [GND]---(15) Read / Write
+  Line (14)------------------------------(13) Controller Select 1
+       (15)               
+  Init (16)------------------------------(12) Controller Select 2
+Select (17)------------------------------(16) Data / Instruction
+Ground (18)---[GND]              [+5v]---(19) LED +
+Ground (19)---[GND]
+Ground (20)---[GND]              E    A             Values:
+Ground (21)---[GND]       [GND]---[P1]---(18) Vee    · R = Resistor = 22 ohm
+Ground (22)---[GND]                |                 · P1 = Preset = 10 Kohm
+Ground (23)---[GND]       ----   S ------( 3) V0     · P2 = Preset = 1 Kohm
+Ground (24)---[GND]       |  |
+Ground (25)---[GND] [GND]---[P2]---[R]---(20) LED -
 
 
 ------------------------
diff -uprN -X dontdiff linux-2.6.19-rc1-modified/drivers/auxdisplay/cfag12864b.c linux/drivers/auxdisplay/cfag12864b.c
--- linux-2.6.19-rc1-modified/drivers/auxdisplay/cfag12864b.c	2006-10-26 16:57:38.000000000 +0000
+++ linux/drivers/auxdisplay/cfag12864b.c	2006-10-26 16:48:36.000000000 +0000
@@ -6,7 +6,7 @@
  *     Depends: ks0108
  *
  *      Author: Copyright (C) Miguel Ojeda Sandonis <maxextreme@gmail.com>
- *        Date: 2006-10-13
+ *        Date: 2006-10-26
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -182,7 +182,7 @@ static void cfag12864b_nop(void)
  * cfag12864b Internal Commands
  */
 
-unsigned char *cfag12864b_cache;
+static unsigned char *cfag12864b_cache;
 unsigned char *cfag12864b_buffer;
 EXPORT_SYMBOL_GPL(cfag12864b_buffer);
 
@@ -264,12 +264,18 @@ static int __init cfag12864b_init(void)
 {
 	int ret = -EINVAL;
 
-	cfag12864b_buffer = vmalloc(sizeof(unsigned char) *
-		CFAG12864B_SIZE);
+	if(PAGE_SIZE < CFAG12864B_SIZE) {
+		printk(KERN_ERR CFAG12864B_NAME ": ERROR: "
+			"page size (%i) < cfag12864b size (%i)\n",
+			(unsigned int)PAGE_SIZE, CFAG12864B_SIZE);
+		ret = -ENOMEM;
+		goto none;
+	}
+
+	cfag12864b_buffer = (unsigned char *) __get_free_page(GFP_KERNEL);
 	if (cfag12864b_buffer == NULL) {
 		printk(KERN_ERR CFAG12864B_NAME ": ERROR: "
-			"can't v-alloc buffer (%i bytes)\n",
-			CFAG12864B_SIZE);
+			"can't get a free page\n");
 		ret = -ENOMEM;
 		goto none;
 	}
@@ -302,7 +308,7 @@ cachealloced:
 	kfree(cfag12864b_cache);
 
 bufferalloced:
-	vfree(cfag12864b_buffer);
+	free_page((unsigned long) cfag12864b_buffer);
 
 none:
 	return ret;
@@ -317,7 +323,7 @@ static void __exit cfag12864b_exit(void)
 	cfag12864b_off();
 
 	kfree(cfag12864b_cache);
-	vfree(cfag12864b_buffer);
+	free_page((unsigned long) cfag12864b_buffer);
 }
 
 module_init(cfag12864b_init);
diff -uprN -X dontdiff linux-2.6.19-rc1-modified/drivers/auxdisplay/cfag12864bfb.c linux/drivers/auxdisplay/cfag12864bfb.c
--- linux-2.6.19-rc1-modified/drivers/auxdisplay/cfag12864bfb.c	2006-10-26 16:57:38.000000000 +0000
+++ linux/drivers/auxdisplay/cfag12864bfb.c	2006-10-26 16:22:42.000000000 +0000
@@ -6,7 +6,7 @@
  *     Depends: cfag12864b
  *
  *      Author: Copyright (C) Miguel Ojeda Sandonis <maxextreme@gmail.com>
- *        Date: 2006-10-13
+ *        Date: 2006-10-26
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -35,12 +35,13 @@
 #include <linux/platform_device.h>
 #include <linux/init.h>
 #include <linux/cfag12864b.h>
+#include <asm/semaphore.h>
 #include <asm/uaccess.h>
 
 #define CFAG12864BFB_NAME "cfag12864bfb"
 
 static struct fb_fix_screeninfo cfag12864bfb_fix __initdata = {
-	.id = "cfag12864b", 
+	.id = "cfag12864b",
 	.type = FB_TYPE_PACKED_PIXELS,
 	.visual = FB_VISUAL_MONO10,
 	.xpanstep = 0,
@@ -66,11 +67,41 @@ static struct fb_var_screeninfo cfag1286
 	.vmode = FB_VMODE_NONINTERLACED,
 };
 
+DECLARE_MUTEX(cfag12864bfb_sem);
+
+struct page *cfag12864bfb_vma_nopage(struct vm_area_struct *vma,
+	unsigned long address, int *type)
+{
+	struct page *page;
+	down(&cfag12864bfb_sem);
+
+	page = virt_to_page(cfag12864b_buffer);
+	get_page(page);
+
+	if(type)
+		*type = VM_FAULT_MINOR;
+
+	up(&cfag12864bfb_sem);
+	return page;
+}
+
+static struct vm_operations_struct cfag12864bfb_vm_ops = {
+	.nopage = cfag12864bfb_vma_nopage,
+};
+
+static int cfag12864bfb_mmap(struct fb_info *info, struct vm_area_struct *vma)
+{
+	vma->vm_ops = &cfag12864bfb_vm_ops;
+	vma->vm_flags |= VM_RESERVED;
+	return 0;
+}
+
 static struct fb_ops cfag12864bfb_ops = {
 	.owner = THIS_MODULE,
 	.fb_fillrect = cfb_fillrect,
 	.fb_copyarea = cfb_copyarea,
 	.fb_imageblit = cfb_imageblit,
+	.fb_mmap = cfag12864bfb_mmap,
 };
 
 static int __init cfag12864bfb_probe(struct platform_device *device)
@@ -81,7 +112,7 @@ static int __init cfag12864bfb_probe(str
 	if (!info)
 		goto none;
 
-	info->screen_base = (char __iomem *)cfag12864b_buffer;
+	info->screen_base = (char __iomem *) cfag12864b_buffer;
 	info->screen_size = CFAG12864B_SIZE;
 	info->fbops = &cfag12864bfb_ops;
 	info->fix = cfag12864bfb_fix;
diff -uprN -X dontdiff linux-2.6.19-rc1-modified/drivers/auxdisplay/Kconfig linux/drivers/auxdisplay/Kconfig
--- linux-2.6.19-rc1-modified/drivers/auxdisplay/Kconfig	2006-10-26 17:01:26.000000000 +0000
+++ linux/drivers/auxdisplay/Kconfig	2006-10-26 17:39:57.000000000 +0000
@@ -71,12 +71,7 @@ config CFAG12864B
 	  say Y. You also need the ks0108 LCD Controller driver.
 
 	  For help about how to wire your LCD to the parallel port,
-	  check this image:
-	  
-	  http://www.skippari.net/lcd/sekalaista/crystalfontz_cfag12864B-TMI-V.png
-
-	  Also, you can find help in Crystalfontz and LCDStudio forums.
-	  Check Documentation/lcddisplay/cfag12864b for more information.
+	  check Documentation/auxdisplay/cfag12864b
 
 	  The LCD framebuffer driver can be attached to a console.
 	  It will work fine. However, you can't attach it to the fbdev driver

Re: [PATCH 2.6.19-rc1 update4] drivers: add LCD support

[Andrew Morton]

On Thu, 26 Oct 2006 17:48:58 +0000
Miguel Ojeda Sandonis <maxextreme@gmail.com> wrote:

>  
> +DECLARE_MUTEX(cfag12864bfb_sem);

Mutexes are preferred - please only use semaphores if their counting
feature is required.

This lock can have static scope.

> +struct page *cfag12864bfb_vma_nopage(struct vm_area_struct *vma,
> +	unsigned long address, int *type)

This function can have static scope.

> +{
> +	struct page *page;
> +	down(&cfag12864bfb_sem);
> +
> +	page = virt_to_page(cfag12864b_buffer);
> +	get_page(page);
> +
> +	if(type)
> +		*type = VM_FAULT_MINOR;
> +
> +	up(&cfag12864bfb_sem);
> +	return page;
> +}

What's the semaphore actually needed for?

Re: [PATCH 2.6.19-rc1 update4] drivers: add LCD support

[Miguel Ojeda]

On 10/27/06, Andrew Morton <akpm@osdl.org> wrote:
> On Thu, 26 Oct 2006 17:48:58 +0000
> Miguel Ojeda Sandonis <maxextreme@gmail.com> wrote:
>
> >
> > +DECLARE_MUTEX(cfag12864bfb_sem);
>
> Mutexes are preferred - please only use semaphores if their counting
> feature is required.
>
> This lock can have static scope.
>
> > +struct page *cfag12864bfb_vma_nopage(struct vm_area_struct *vma,
> > +     unsigned long address, int *type)
>
> This function can have static scope.
>
> > +{
> > +     struct page *page;
> > +     down(&cfag12864bfb_sem);
> > +
> > +     page = virt_to_page(cfag12864b_buffer);
> > +     get_page(page);
> > +
> > +     if(type)
> > +             *type = VM_FAULT_MINOR;
> > +
> > +     up(&cfag12864bfb_sem);
> > +     return page;
> > +}
>
> What's the semaphore actually needed for?
>

Hum, the code is based on LDD3, I just adapted it removing a few
lines. I thought this code also needed lock protection as the LDD3
example. I'm sending a new patch in a few moments with this 3 things
fixed.

Thanks you,
     Miguel Ojeda

[PATCH 2.6.19-rc1 update4] drivers: add LCD support

[Miguel Ojeda Sandonis]

Andrew, here it is the same patch without locking. Thanks you.
---

 - Adds mmaping support for the cfag12864bfb.
 - Exchange the wiring drawing URL to a local ASCII drawing
   at Documentation/auxdisplay/cfag12864b.
 - Minor coding style and documentation fixes.

 Documentation/auxdisplay/cfag12864b |   57 +++++++++++++++++++-------
 Documentation/auxdisplay/ks0108     |   14 ++----
 drivers/auxdisplay/Kconfig          |    7 ---
 drivers/auxdisplay/cfag12864b.c     |   28 +++++++-----
 drivers/auxdisplay/cfag12864bfb.c   |   30 ++++++++++++-
 5 files changed, 93 insertions(+), 43 deletions(-)

miguelojeda-2.6.19-rc1-drivers-add-LCD-support-4-mmaping-and-ascii-drawing.patch
Signed-off-by: Miguel Ojeda Sandonis <maxextreme@gmail.com>
---
diff -uprN -X dontdiff linux-2.6.19-rc1-modified/Documentation/auxdisplay/cfag12864b linux/Documentation/auxdisplay/cfag12864b
--- linux-2.6.19-rc1-modified/Documentation/auxdisplay/cfag12864b	2006-10-26 16:57:38.000000000 +0000
+++ linux/Documentation/auxdisplay/cfag12864b	2006-10-27 15:33:01.000000000 +0000
@@ -4,7 +4,7 @@
 
 License:		GPLv2
 Author & Maintainer:	Miguel Ojeda Sandonis <maxextreme@gmail.com>
-Date:			2006-10-11
+Date:			2006-10-27
 
 
 
@@ -15,7 +15,7 @@ Date:			2006-10-11
 	1. DRIVER INFORMATION
 	2. DEVICE INFORMATION
 	3. WIRING
-	4. USER-SPACE PROGRAMMING
+	4. USERSPACE PROGRAMMING
 
 
 ---------------------
@@ -42,7 +42,8 @@ Controller:	ks0108
 Controllers:	2
 Pages:		8 each controller
 Addresses:	64 each page
-
+Data size:	1 byte each address
+Memory size:	2 * 8 * 64 * 1 = 1024 bytes = 1 Kbyte
 
 
 ---------
@@ -51,25 +52,53 @@ Addresses:	64 each page
 
 The cfag12864b LCD Series don't have official wiring.
 
-The common wiring is done to the parallel port:
-
-http://www.skippari.net/lcd/sekalaista/crystalfontz_cfag12864B-TMI-V.png
-
-You can get help at Crystalfontz and LCDInfo forums.
+The common wiring is done to the parallel port as shown:
 
+Parallel Port                          cfag12864b
+
+  Name Pin#                            Pin# Name
+
+Strobe ( 1)------------------------------(17) Enable
+Data 0 ( 2)------------------------------( 4) Data 0
+Data 1 ( 3)------------------------------( 5) Data 1
+Data 2 ( 4)------------------------------( 6) Data 2
+Data 3 ( 5)------------------------------( 7) Data 3
+Data 4 ( 6)------------------------------( 8) Data 4
+Data 5 ( 7)------------------------------( 9) Data 5
+Data 6 ( 8)------------------------------(10) Data 6
+Data 7 ( 9)------------------------------(11) Data 7
+       (10)                      [+5v]---( 1) Vdd
+       (11)                      [GND]---( 2) Ground
+       (12)                      [+5v]---(14) Reset
+       (13)                      [GND]---(15) Read / Write
+  Line (14)------------------------------(13) Controller Select 1
+       (15)               
+  Init (16)------------------------------(12) Controller Select 2
+Select (17)------------------------------(16) Data / Instruction
+Ground (18)---[GND]              [+5v]---(19) LED +
+Ground (19)---[GND]
+Ground (20)---[GND]              E    A             Values:
+Ground (21)---[GND]       [GND]---[P1]---(18) Vee    · R = Resistor = 22 ohm
+Ground (22)---[GND]                |                 · P1 = Preset = 10 Kohm
+Ground (23)---[GND]       ----   S ------( 3) V0     · P2 = Preset = 1 Kohm
+Ground (24)---[GND]       |  |
+Ground (25)---[GND] [GND]---[P2]---[R]---(20) LED -
 
 
 ------------------------
 4. USERSPACE PROGRAMMING
 ------------------------
 
-The cfag12864bfb describes a framebuffer driver (/dev/fbX).
+The cfag12864bfb describes a framebuffer device (/dev/fbX).
 
-It has a size of 128 * 64 / 8 = 1024 bytes = 1 kB.
+It has a size of 1024 bytes = 1 Kbyte.
 Each bit represents one pixel. If the bit is high, the pixel will
 turn on. If the pixel is low, the pixel will turn off.
 
-You can mmap the framebuffer as usual.
+You can use the framebuffer as a file: fopen, fwrite, fclose...
+
+Also, you can mmap the framebuffer: open & mmap, munmap & close...
+which is the best option.
 
 You can use a copy of this header in your userspace programs.
 
@@ -79,7 +108,7 @@ You can use a copy of this header in you
  * Description: cfag12864b LCD Display Driver Header for user-space apps
  *
  *      Author: Miguel Ojeda Sandonis <maxextreme@gmail.com>
- *        Date: 2006-10-11
+ *        Date: 2006-10-27
  */
 
 #ifndef _CFAG12864B_H_
@@ -87,9 +116,7 @@ You can use a copy of this header in you
 
 #define CFAG12864B_WIDTH	(128)
 #define CFAG12864B_HEIGHT	(64)
-#define CFAG12864B_SIZE		((CFAG12864B_CONTROLLERS) * \
-				(CFAG12864B_PAGES) * \
-				(CFAG12864B_ADDRESSES))
+#define CFAG12864B_SIZE		(1024)
 
 #endif // _CFAG12864B_H_
 ---8<---
diff -uprN -X dontdiff linux-2.6.19-rc1-modified/Documentation/auxdisplay/ks0108 linux/Documentation/auxdisplay/ks0108
--- linux-2.6.19-rc1-modified/Documentation/auxdisplay/ks0108	2006-10-26 16:57:38.000000000 +0000
+++ linux/Documentation/auxdisplay/ks0108	2006-10-27 15:32:48.000000000 +0000
@@ -4,7 +4,7 @@
 
 License:		GPLv2
 Author & Maintainer:	Miguel Ojeda Sandonis <maxextreme@gmail.com>
-Date:			2006-10-04
+Date:			2006-10-27
 
 
 
@@ -39,7 +39,8 @@ Height:		64
 Colors:		2 (B/N)
 Pages:		8
 Addresses:	64 each page
-
+Data size:	1 byte each address
+Memory size:	8 * 64 * 1 = 512 bytes
 
 
 ---------
@@ -48,12 +49,9 @@ Addresses:	64 each page
 
 The driver supports data parallel port wiring.
 
-If you aren't creating a LCD related hardware, you should check
-your LCD specific wiring information in the same folder, not this one.
-
-
-Wiring example of a cfag12864b LCD which has two ks0108 controllers:
+If you aren't building LCD related hardware, you should check
+your LCD specific wiring information in the same folder.
 
-http://www.skippari.net/lcd/sekalaista/crystalfontz_cfag12864B-TMI-V.png
+For example, check Documentation/auxdisplay/cfag12864b.
 
 EOF
diff -uprN -X dontdiff linux-2.6.19-rc1-modified/drivers/auxdisplay/cfag12864b.c linux/drivers/auxdisplay/cfag12864b.c
--- linux-2.6.19-rc1-modified/drivers/auxdisplay/cfag12864b.c	2006-10-26 16:57:38.000000000 +0000
+++ linux/drivers/auxdisplay/cfag12864b.c	2006-10-27 15:23:04.000000000 +0000
@@ -6,7 +6,7 @@
  *     Depends: ks0108
  *
  *      Author: Copyright (C) Miguel Ojeda Sandonis <maxextreme@gmail.com>
- *        Date: 2006-10-13
+ *        Date: 2006-10-26
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -182,7 +182,7 @@ static void cfag12864b_nop(void)
  * cfag12864b Internal Commands
  */
 
-unsigned char *cfag12864b_cache;
+static unsigned char *cfag12864b_cache;
 unsigned char *cfag12864b_buffer;
 EXPORT_SYMBOL_GPL(cfag12864b_buffer);
 
@@ -226,7 +226,7 @@ static void cfag12864b_update(void *arg)
 	unsigned char c;
 	unsigned short i, j, k, b;
 
-	if(memcmp(cfag12864b_cache, cfag12864b_buffer, CFAG12864B_SIZE)) {
+	if (memcmp(cfag12864b_cache, cfag12864b_buffer, CFAG12864B_SIZE)) {
 		for (i = 0; i < CFAG12864B_CONTROLLERS; i++) {
 			cfag12864b_controller(i);
 			cfag12864b_nop();
@@ -251,7 +251,7 @@ static void cfag12864b_update(void *arg)
 		memcpy(cfag12864b_cache, cfag12864b_buffer, CFAG12864B_SIZE);
 	}
 
-	if(cfag12864b_updating)
+	if (cfag12864b_updating)
 		queue_delayed_work(cfag12864b_workqueue, &cfag12864b_work,
 			HZ / cfag12864b_rate);
 }
@@ -264,12 +264,18 @@ static int __init cfag12864b_init(void)
 {
 	int ret = -EINVAL;
 
-	cfag12864b_buffer = vmalloc(sizeof(unsigned char) *
-		CFAG12864B_SIZE);
+	if (PAGE_SIZE < CFAG12864B_SIZE) {
+		printk(KERN_ERR CFAG12864B_NAME ": ERROR: "
+			"page size (%i) < cfag12864b size (%i)\n",
+			(unsigned int)PAGE_SIZE, CFAG12864B_SIZE);
+		ret = -ENOMEM;
+		goto none;
+	}
+
+	cfag12864b_buffer = (unsigned char *) __get_free_page(GFP_KERNEL);
 	if (cfag12864b_buffer == NULL) {
 		printk(KERN_ERR CFAG12864B_NAME ": ERROR: "
-			"can't v-alloc buffer (%i bytes)\n",
-			CFAG12864B_SIZE);
+			"can't get a free page\n");
 		ret = -ENOMEM;
 		goto none;
 	}
@@ -290,7 +296,7 @@ static int __init cfag12864b_init(void)
 	cfag12864b_on();
 
 	cfag12864b_workqueue = create_singlethread_workqueue(CFAG12864B_NAME);
-	if(cfag12864b_workqueue == NULL)
+	if (cfag12864b_workqueue == NULL)
 		goto cachealloced;
 
 	cfag12864b_updating = 1;
@@ -302,7 +308,7 @@ cachealloced:
 	kfree(cfag12864b_cache);
 
 bufferalloced:
-	vfree(cfag12864b_buffer);
+	free_page((unsigned long) cfag12864b_buffer);
 
 none:
 	return ret;
@@ -317,7 +323,7 @@ static void __exit cfag12864b_exit(void)
 	cfag12864b_off();
 
 	kfree(cfag12864b_cache);
-	vfree(cfag12864b_buffer);
+	free_page((unsigned long) cfag12864b_buffer);
 }
 
 module_init(cfag12864b_init);
diff -uprN -X dontdiff linux-2.6.19-rc1-modified/drivers/auxdisplay/cfag12864bfb.c linux/drivers/auxdisplay/cfag12864bfb.c
--- linux-2.6.19-rc1-modified/drivers/auxdisplay/cfag12864bfb.c	2006-10-26 16:57:38.000000000 +0000
+++ linux/drivers/auxdisplay/cfag12864bfb.c	2006-10-27 15:23:12.000000000 +0000
@@ -6,7 +6,7 @@
  *     Depends: cfag12864b
  *
  *      Author: Copyright (C) Miguel Ojeda Sandonis <maxextreme@gmail.com>
- *        Date: 2006-10-13
+ *        Date: 2006-10-26
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -40,7 +40,7 @@
 #define CFAG12864BFB_NAME "cfag12864bfb"
 
 static struct fb_fix_screeninfo cfag12864bfb_fix __initdata = {
-	.id = "cfag12864b", 
+	.id = "cfag12864b",
 	.type = FB_TYPE_PACKED_PIXELS,
 	.visual = FB_VISUAL_MONO10,
 	.xpanstep = 0,
@@ -66,11 +66,35 @@ static struct fb_var_screeninfo cfag1286
 	.vmode = FB_VMODE_NONINTERLACED,
 };
 
+static struct page *cfag12864bfb_vma_nopage(struct vm_area_struct *vma,
+	unsigned long address, int *type)
+{
+	struct page *page = virt_to_page(cfag12864b_buffer);
+	get_page(page);
+
+	if(type)
+		*type = VM_FAULT_MINOR;
+
+	return page;
+}
+
+static struct vm_operations_struct cfag12864bfb_vm_ops = {
+	.nopage = cfag12864bfb_vma_nopage,
+};
+
+static int cfag12864bfb_mmap(struct fb_info *info, struct vm_area_struct *vma)
+{
+	vma->vm_ops = &cfag12864bfb_vm_ops;
+	vma->vm_flags |= VM_RESERVED;
+	return 0;
+}
+
 static struct fb_ops cfag12864bfb_ops = {
 	.owner = THIS_MODULE,
 	.fb_fillrect = cfb_fillrect,
 	.fb_copyarea = cfb_copyarea,
 	.fb_imageblit = cfb_imageblit,
+	.fb_mmap = cfag12864bfb_mmap,
 };
 
 static int __init cfag12864bfb_probe(struct platform_device *device)
@@ -81,7 +105,7 @@ static int __init cfag12864bfb_probe(str
 	if (!info)
 		goto none;
 
-	info->screen_base = (char __iomem *)cfag12864b_buffer;
+	info->screen_base = (char __iomem *) cfag12864b_buffer;
 	info->screen_size = CFAG12864B_SIZE;
 	info->fbops = &cfag12864bfb_ops;
 	info->fix = cfag12864bfb_fix;
diff -uprN -X dontdiff linux-2.6.19-rc1-modified/drivers/auxdisplay/Kconfig linux/drivers/auxdisplay/Kconfig
--- linux-2.6.19-rc1-modified/drivers/auxdisplay/Kconfig	2006-10-26 17:01:26.000000000 +0000
+++ linux/drivers/auxdisplay/Kconfig	2006-10-26 17:39:57.000000000 +0000
@@ -71,12 +71,7 @@ config CFAG12864B
 	  say Y. You also need the ks0108 LCD Controller driver.
 
 	  For help about how to wire your LCD to the parallel port,
-	  check this image:
-	  
-	  http://www.skippari.net/lcd/sekalaista/crystalfontz_cfag12864B-TMI-V.png
-
-	  Also, you can find help in Crystalfontz and LCDStudio forums.
-	  Check Documentation/lcddisplay/cfag12864b for more information.
+	  check Documentation/auxdisplay/cfag12864b
 
 	  The LCD framebuffer driver can be attached to a console.
 	  It will work fine. However, you can't attach it to the fbdev driver

Re: [PATCH 2.6.19-rc1 update4] drivers: add LCD support

[Franck Bui-Huu]

Andrew,

Andrew Morton wrote:
> On Thu, 26 Oct 2006 17:48:58 +0000
> Miguel Ojeda Sandonis <maxextreme@gmail.com> wrote:
> 
[snip]
> 
>> +struct page *cfag12864bfb_vma_nopage(struct vm_area_struct *vma,
>> +	unsigned long address, int *type)
> 
> This function can have static scope.
> 
>> +{
>> +	struct page *page;
>> +	down(&cfag12864bfb_sem);
>> +
>> +	page = virt_to_page(cfag12864b_buffer);
>> +	get_page(page);
>> +
>> +	if(type)
>> +		*type = VM_FAULT_MINOR;
>> +
>> +	up(&cfag12864bfb_sem);
>> +	return page;
>> +}
> 

Any idea why LDD3 states:

	An interesting limitation of remap_pfn_range is that it gives
	access only to reserved pages and physical addresses above the
	top of physical memory.

Is that true we can't do:

	buf = (char *)__get_free_page(...);
	pfn = PFN_DOWN(virt_to_phys(buf));
	remap_pfn_range(vma, vma->vm_start, pfn, PAGE_SIZE, vma->vm_page_prot);

Thanks
		Franck

Re: [PATCH 2.6.19-rc1 update4] drivers: add LCD support

[Miguel Ojeda]

On 10/30/06, Franck Bui-Huu <vagabon.xyz@gmail.com> wrote:
> Andrew,
>
> Andrew Morton wrote:
> > On Thu, 26 Oct 2006 17:48:58 +0000
> > Miguel Ojeda Sandonis <maxextreme@gmail.com> wrote:
> >
> [snip]
> >
> >> +struct page *cfag12864bfb_vma_nopage(struct vm_area_struct *vma,
> >> +    unsigned long address, int *type)
> >
> > This function can have static scope.
> >
> >> +{
> >> +    struct page *page;
> >> +    down(&cfag12864bfb_sem);
> >> +
> >> +    page = virt_to_page(cfag12864b_buffer);
> >> +    get_page(page);
> >> +
> >> +    if(type)
> >> +            *type = VM_FAULT_MINOR;
> >> +
> >> +    up(&cfag12864bfb_sem);
> >> +    return page;
> >> +}
> >
>
> Any idea why LDD3 states:
>
>         An interesting limitation of remap_pfn_range is that it gives
>         access only to reserved pages and physical addresses above the
>         top of physical memory.
>
> Is that true we can't do:
>
>         buf = (char *)__get_free_page(...);
>         pfn = PFN_DOWN(virt_to_phys(buf));
>         remap_pfn_range(vma, vma->vm_start, pfn, PAGE_SIZE, vma->vm_page_prot);
>
> Thanks
>                 Franck
>

Again: Please read LDD3. It explains it well. Read all the "Remapping
RAM" chapter and you will understand what I've done, or just try to
remap RAM yourself with remap_pfn_range. (I really tried it using
different ways and I couldn't map it with remap_pfn_range, it returns
you a place full with zeros, as LDD3 states).

Re: [PATCH 2.6.19-rc1 update4] drivers: add LCD support

[Hugh Dickins]

On Mon, 30 Oct 2006, Franck Bui-Huu wrote:
> 
> Any idea why LDD3 states:
> 
> 	An interesting limitation of remap_pfn_range is that it gives
> 	access only to reserved pages and physical addresses above the
> 	top of physical memory.

It was true until 2.6.15, when VM_PFNMAP removed that restriction to
PageReserved (or struct-page-less) pages.

Hugh

Re: [PATCH 2.6.19-rc1 update4] drivers: add LCD support

[Franck Bui-Huu]

Miguel Ojeda Sandonis wrote:
> Andrew, here it is the same patch without locking. Thanks you.

Last concern: did you think about cache aliasings ?

bye
		Franck

Re: [PATCH 2.6.19-rc1 update4] drivers: add LCD support

[Franck Bui-Huu]

Miguel Ojeda wrote:
> Again: Please read LDD3. It explains it well. Read all the "Remapping
> RAM" chapter and you will understand what I've done, or just try to
> remap RAM yourself with remap_pfn_range. 

Well, I'm trying to get an explanation here and here is what I get
from you:

MO  > LDD3 states it must work like this. (Note: it doesn't explain
      why though)
FBH > Weird I read the implementation of remap_pfn_range() and it 
      doesn't seem to have such restriction, I'm wondering how
      things work...
MO  > Again it's stated in LDD3, read again.

Do you really think you explain anything with such replies ?

Fortunately, Hugh Dickins gives a hint and it appears that the
restriction doesn't hold anymore.

> (I really tried it using
> different ways and I couldn't map it with remap_pfn_range, it returns
> you a place full with zeros, as LDD3 states).

I'm really wondering how did you test the thing... ;)

bye
		Franck

Re: [PATCH 2.6.19-rc1 update4] drivers: add LCD support

[Miguel Ojeda]

On 10/31/06, Franck Bui-Huu <vagabon.xyz@gmail.com> wrote:
> Miguel Ojeda wrote:
> > Again: Please read LDD3. It explains it well. Read all the "Remapping
> > RAM" chapter and you will understand what I've done, or just try to
> > remap RAM yourself with remap_pfn_range.
>
> Well, I'm trying to get an explanation here and here is what I get
> from you:
>
> MO  > LDD3 states it must work like this. (Note: it doesn't explain
>       why though)
> FBH > Weird I read the implementation of remap_pfn_range() and it
>       doesn't seem to have such restriction, I'm wondering how
>       things work...
> MO  > Again it's stated in LDD3, read again.
>
> Do you really think you explain anything with such replies ?
>

Do you really think I have to explain anything with my replies? I was
just trying to help you telling where I found the answer.

Anyway, isn't it explained in LDD3? isn't it stated in LDD3? I think
it is (yep, not deeply, but enough: other books cover that points
better and a device driver programmer doesn't have to know about
implementations, right?). Sure, neither the book or I didn't know
about the VM_PFNMAP change, but that doesn't change that I was trying
to encourage you to read such chapter, the same way I found the answer
there.

>
> Fortunately, Hugh Dickins gives a hint and it appears that the
> restriction doesn't hold anymore.
>
> > (I really tried it using
> > different ways and I couldn't map it with remap_pfn_range, it returns
> > you a place full with zeros, as LDD3 states).
>
> I'm really wondering how did you test the thing... ;)
>

And I still say I tried it, many ways, using remap_pfn_range() and
other weird things also. Finally, I thought something was wrong, so I
read LDD3 and I found the explanation about why my code mmap couldn't
mmap RAM. Also, my area was full of zeros, as LDD3 states. So I read a
little further and I did what "Remapping RAM" explains.

Anything else?

Bye,
       Miguel Ojeda