2007-06-15 08:58:21

by Nicolas Ferre

[permalink] [raw]
Subject: [PATCH] atmel_lcdfb: Fix STN LCD support

From: Nicolas Ferre <[email protected]>

Fixes STN LCD support for the atmel_lcdfb framebuffer driver.

Signed-off-by: Nicolas Ferre <[email protected]>
---

This patch is the result of a work from Jan Altenberg and has
been tested on a Hitachi SP06Q002 on at91sam9261ek.

It adds a Kconfig switch that enables the proper LCD in the
board configuration file (STN or TFT).

This patch includes the "Fix wrong line_length calculation"
little one from Jan and Haavard (submitted earlier).

AT91 platform informations are directly submitted trough
the at91 maintainer and follow in a [RFC] message.

drivers/video/Kconfig | 10 +++++
drivers/video/atmel_lcdfb.c | 62 +++++++++++++++++++++++++++++-----
2 files changed, 64 insertions(+), 8 deletions(-)

Index: b/drivers/video/atmel_lcdfb.c
===================================================================
--- a/drivers/video/atmel_lcdfb.c 2007-06-13 10:55:42.000000000 +0200
+++ b/drivers/video/atmel_lcdfb.c 2007-06-15 10:25:06.000000000 +0200
@@ -79,6 +79,29 @@
.accel = FB_ACCEL_NONE,
};

+static unsigned long compute_hozval(unsigned long xres, unsigned long lcdcon2)
+{
+ unsigned long value;
+
+ if (!(cpu_is_at91sam9261() || cpu_is_at32ap7000()))
+ return xres;
+
+ value = xres;
+ if ((lcdcon2 & ATMEL_LCDC_DISTYPE) != ATMEL_LCDC_DISTYPE_TFT) {
+ /* STN display */
+ if ((lcdcon2 & ATMEL_LCDC_DISTYPE) == ATMEL_LCDC_DISTYPE_STNCOLOR) {
+ value *= 3;
+ }
+ if ( (lcdcon2 & ATMEL_LCDC_IFWIDTH) == ATMEL_LCDC_IFWIDTH_4
+ || ( (lcdcon2 & ATMEL_LCDC_IFWIDTH) == ATMEL_LCDC_IFWIDTH_8
+ && (lcdcon2 & ATMEL_LCDC_SCANMOD) == ATMEL_LCDC_SCANMOD_DUAL ))
+ value = DIV_ROUND_UP(value, 4);
+ else
+ value = DIV_ROUND_UP(value, 8);
+ }
+
+ return value;
+}

static void atmel_lcdfb_update_dma(struct fb_info *info,
struct fb_var_screeninfo *var)
@@ -181,6 +204,7 @@
var->xoffset = var->yoffset = 0;

switch (var->bits_per_pixel) {
+ case 1:
case 2:
case 4:
case 8:
@@ -228,8 +252,10 @@
static int atmel_lcdfb_set_par(struct fb_info *info)
{
struct atmel_lcdfb_info *sinfo = info->par;
+ unsigned long hozval_linesz;
unsigned long value;
unsigned long clk_value_khz;
+ unsigned long bits_per_line;

dev_dbg(info->device, "%s:\n", __func__);
dev_dbg(info->device, " * resolution: %ux%u (%ux%u virtual)\n",
@@ -241,12 +267,15 @@

lcdc_writel(sinfo, ATMEL_LCDC_DMACON, 0);

- if (info->var.bits_per_pixel <= 8)
+ if (info->var.bits_per_pixel == 1)
+ info->fix.visual = FB_VISUAL_MONO01;
+ else if (info->var.bits_per_pixel <= 8)
info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
else
info->fix.visual = FB_VISUAL_TRUECOLOR;

- info->fix.line_length = info->var.xres_virtual * (info->var.bits_per_pixel / 8);
+ bits_per_line = info->var.xres_virtual * info->var.bits_per_pixel;
+ info->fix.line_length = DIV_ROUND_UP(bits_per_line, 8);

/* Re-initialize the DMA engine... */
dev_dbg(info->device, " * update DMA engine\n");
@@ -262,18 +291,21 @@
/* Set pixel clock */
clk_value_khz = clk_get_rate(sinfo->lcdc_clk) / 1000;

- value = clk_value_khz / PICOS2KHZ(info->var.pixclock);
-
- if (clk_value_khz % PICOS2KHZ(info->var.pixclock))
- value++;
+ value = DIV_ROUND_UP(clk_value_khz, PICOS2KHZ(info->var.pixclock));

value = (value / 2) - 1;
+ dev_dbg(info->device, " * programming CLKVAL = 0x%08lx\n", value);

if (value <= 0) {
dev_notice(info->device, "Bypassing pixel clock divider\n");
lcdc_writel(sinfo, ATMEL_LCDC_LCDCON1, ATMEL_LCDC_BYPASS);
- } else
+ } else {
lcdc_writel(sinfo, ATMEL_LCDC_LCDCON1, value << ATMEL_LCDC_CLKVAL_OFFSET);
+ info->var.pixclock = KHZ2PICOS(clk_value_khz / (2 * (value + 1)));
+ dev_dbg(info->device, " updated pixclk: %lu KHz\n",
+ PICOS2KHZ(info->var.pixclock));
+ }
+

/* Initialize control register 2 */
value = sinfo->default_lcdcon2;
@@ -311,9 +343,14 @@
dev_dbg(info->device, " * LCDTIM2 = %08lx\n", value);
lcdc_writel(sinfo, ATMEL_LCDC_TIM2, value);

+ /* Horizontal value (aka line size) */
+ hozval_linesz = compute_hozval(info->var.xres,
+ lcdc_readl(sinfo, ATMEL_LCDC_LCDCON2));
+
/* Display size */
- value = (info->var.xres - 1) << ATMEL_LCDC_HOZVAL_OFFSET;
+ value = (hozval_linesz - 1) << ATMEL_LCDC_HOZVAL_OFFSET;
value |= info->var.yres - 1;
+ dev_dbg(info->device, " * LCDFRMCFG = %08lx\n", value);
lcdc_writel(sinfo, ATMEL_LCDC_LCDFRMCFG, value);

/* FIFO Threshold: Use formula from data sheet */
@@ -421,6 +458,15 @@
ret = 0;
}
break;
+
+ case FB_VISUAL_MONO01:
+ if (regno < 2) {
+ val = (regno == 0) ? 0x00 : 0x1F;
+ lcdc_writel(sinfo, ATMEL_LCDC_LUT(regno), val);
+ ret = 0;
+ }
+ break;
+
}

return ret;
Index: b/drivers/video/Kconfig
===================================================================
--- a/drivers/video/Kconfig 2007-05-14 11:02:16.000000000 +0200
+++ b/drivers/video/Kconfig 2007-06-13 11:04:10.000000000 +0200
@@ -701,6 +701,16 @@
Say Y if you want to map Frame Buffer in internal SRAM. Say N if you want
to let frame buffer in external SDRAM.

+config FB_ATMEL_STN
+ bool "Use a STN display with AT91/AT32 LCD Controller"
+ depends on FB_ATMEL && ARCH_AT91SAM9261
+ default n
+ help
+ Say Y if you want to connect a STN LCD display to the AT91/AT32 LCD
+ Controller. Say N if you want to connect a TFT.
+
+ If unsure, say N.
+
config FB_NVIDIA
tristate "nVidia Framebuffer Support"
depends on FB && PCI

--
Nicolas Ferre



2007-06-15 09:14:19

by Jan Altenberg

[permalink] [raw]
Subject: Re: [PATCH] atmel_lcdfb: Fix STN LCD support

On Fri, 2007-06-15 at 10:50 +0200, Nicolas Ferre wrote:
> From: Nicolas Ferre <[email protected]>
>
> Fixes STN LCD support for the atmel_lcdfb framebuffer driver.
>
> Signed-off-by: Nicolas Ferre <[email protected]>

Acked-by: Jan Altenberg <[email protected]>

2007-06-19 07:49:12

by Haavard Skinnemoen

[permalink] [raw]
Subject: Re: [PATCH] atmel_lcdfb: Fix STN LCD support

On Fri, 15 Jun 2007 10:50:12 +0200
Nicolas Ferre <[email protected]> wrote:

> From: Nicolas Ferre <[email protected]>
>
> Fixes STN LCD support for the atmel_lcdfb framebuffer driver.
>
> Signed-off-by: Nicolas Ferre <[email protected]>

Looks correct to me. Although...

> Index: b/drivers/video/Kconfig
> ===================================================================
> --- a/drivers/video/Kconfig 2007-05-14 11:02:16.000000000 +0200
> +++ b/drivers/video/Kconfig 2007-06-13 11:04:10.000000000 +0200
> @@ -701,6 +701,16 @@
> Say Y if you want to map Frame Buffer in internal SRAM. Say N if you want
> to let frame buffer in external SDRAM.
>
> +config FB_ATMEL_STN
> + bool "Use a STN display with AT91/AT32 LCD Controller"
> + depends on FB_ATMEL && ARCH_AT91SAM9261
> + default n
> + help
> + Say Y if you want to connect a STN LCD display to the AT91/AT32 LCD
> + Controller. Say N if you want to connect a TFT.
> +
> + If unsure, say N.
> +

I don't think it's appropriate to include chip-specific options here.
This option will not affect the driver at all, it will only affect the
board-specific setup code, so IMO it should be under Platform-specific
options or something like that.

Also, the text says AT91/AT32 but it depends on one particular AT91
chip.

I haven't had a chance to test it since I don't have any STN displays
around, but I'll try forwarding it to someone who has.

Haavard

2007-06-20 12:11:04

by Nicolas Ferre

[permalink] [raw]
Subject: Re: [PATCH] atmel_lcdfb: Fix STN LCD support

Haavard Skinnemoen :
> On Fri, 15 Jun 2007 10:50:12 +0200
> Nicolas Ferre <[email protected]> wrote:
>
>> From: Nicolas Ferre <[email protected]>
>>
>> Fixes STN LCD support for the atmel_lcdfb framebuffer driver.
>>
>> Signed-off-by: Nicolas Ferre <[email protected]>
>
> Looks correct to me. Although...
>
>> Index: b/drivers/video/Kconfig
>> ===================================================================
>> --- a/drivers/video/Kconfig 2007-05-14 11:02:16.000000000 +0200
>> +++ b/drivers/video/Kconfig 2007-06-13 11:04:10.000000000 +0200
>> @@ -701,6 +701,16 @@
>> Say Y if you want to map Frame Buffer in internal SRAM. Say N if you want
>> to let frame buffer in external SDRAM.
>>
>> +config FB_ATMEL_STN
>> + bool "Use a STN display with AT91/AT32 LCD Controller"
>> + depends on FB_ATMEL && ARCH_AT91SAM9261
>> + default n
>> + help
>> + Say Y if you want to connect a STN LCD display to the AT91/AT32 LCD
>> + Controller. Say N if you want to connect a TFT.
>> +
>> + If unsure, say N.
>> +
>
> I don't think it's appropriate to include chip-specific options here.
> This option will not affect the driver at all, it will only affect the
> board-specific setup code, so IMO it should be under Platform-specific
> options or something like that.

True in a "code centric" point of view. I do not think it is very usable
to move this switch in the board setup : The user will have to check if
an option is appearing in the board menu while he select the Atmel LCD
driver. He is supposed to have already selected the chip'n'board he is
using.
Moreover, this option will not show its nose until the board that
implements it is not included in depends.
(It is basically the same case with the option just above, with the very
same arguments).

> Also, the text says AT91/AT32 but it depends on one particular AT91
> chip.

Ok, will move it to a board switch (MACH_AT91SAM9261EK for instance).
This will grow as STN configuration will be implemented for boards.

Regards,
--
Nicolas Ferre