From: Kronos <kronos@kronoz.cjb.net>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: linux-fbdev-devel@lists.sourceforge.net
Subject: [PATCH] Remove voodoo code from i2c
Date: Fri, 5 Mar 2004 22:52:10 +0100 [thread overview]
Message-ID: <20040305215210.GA23402@dreamland.darkstar.lan> (raw)
Hi,
radeon_probe_i2c_connector contains very strange code that just send
empty start-stop sequencies on the I2C bus. I copied the code from
XFree86, but speaking with I2C gurus the general feeling is that this
code can go away without any harm. I tested it on 3 different setup (all
x86...) and it works well. I don't have any "old" monitor around to
fiddle with though.
Oh, if you think that this code should stay I'll send you another patch
to make it more readable.
===== drivers/video/aty/radeon_i2c.c 1.3 vs edited =====
--- 1.3/drivers/video/aty/radeon_i2c.c Wed Feb 18 07:02:05 2004
+++ edited/drivers/video/aty/radeon_i2c.c Fri Mar 5 22:44:21 2004
@@ -180,59 +180,9 @@
OUTREG(reg, INREG(reg) &
~(VGA_DDC_DATA_OUTPUT | VGA_DDC_CLK_OUTPUT));
- OUTREG(reg, INREG(reg) & ~(VGA_DDC_CLK_OUT_EN));
- (void)INREG(reg);
-
for (i = 0; i < 3; i++) {
- /* For some old monitors we need the
- * following process to initialize/stop DDC
- */
- OUTREG(reg, INREG(reg) & ~(VGA_DDC_DATA_OUT_EN));
- (void)INREG(reg);
- wait_ms(13);
-
- OUTREG(reg, INREG(reg) & ~(VGA_DDC_CLK_OUT_EN));
- (void)INREG(reg);
- for (j = 0; j < 5; j++) {
- wait_ms(10);
- if (INREG(reg) & VGA_DDC_CLK_INPUT)
- break;
- }
- if (j == 5)
- continue;
-
- OUTREG(reg, INREG(reg) | VGA_DDC_DATA_OUT_EN);
- (void)INREG(reg);
- wait_ms(15);
- OUTREG(reg, INREG(reg) | VGA_DDC_CLK_OUT_EN);
- (void)INREG(reg);
- wait_ms(15);
- OUTREG(reg, INREG(reg) & ~(VGA_DDC_DATA_OUT_EN));
- (void)INREG(reg);
- wait_ms(15);
-
/* Do the real work */
edid = radeon_do_probe_i2c_edid(&rinfo->i2c[conn-1]);
-
- OUTREG(reg, INREG(reg) |
- (VGA_DDC_DATA_OUT_EN | VGA_DDC_CLK_OUT_EN));
- (void)INREG(reg);
- wait_ms(15);
-
- OUTREG(reg, INREG(reg) & ~(VGA_DDC_CLK_OUT_EN));
- (void)INREG(reg);
- for (j = 0; j < 10; j++) {
- wait_ms(10);
- if (INREG(reg) & VGA_DDC_CLK_INPUT)
- break;
- }
-
- OUTREG(reg, INREG(reg) & ~(VGA_DDC_DATA_OUT_EN));
- (void)INREG(reg);
- wait_ms(15);
- OUTREG(reg, INREG(reg) |
- (VGA_DDC_DATA_OUT_EN | VGA_DDC_CLK_OUT_EN));
- (void)INREG(reg);
if (edid)
break;
}
Luca
--
Home: http://kronoz.cjb.net
Runtime error 6D at f000:a12f : user incompetente
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next reply other threads:[~2004-03-05 22:06 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-03-05 21:52 Kronos [this message]
2004-03-05 23:55 ` [PATCH] Remove voodoo code from i2c Benjamin Herrenschmidt
2004-03-06 0:47 ` Kronos
2004-03-06 2:10 ` Jon Smirl
2004-03-06 3:42 ` Benjamin Herrenschmidt
2004-03-06 4:02 ` Jon Smirl
2004-03-06 15:08 ` Kronos
2004-03-08 22:17 ` Richard Smith
2004-03-08 22:56 ` Benjamin Herrenschmidt
2004-03-06 0:12 ` Michel Dänzer
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