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Re: [PATCH 3/3 v2] cyber2000fb: add I2C support

Previous thread: [PATCH 2/3] cyber2000fb: add mode_option parameter by Ondrej Zary on Saturday, July 31, 2010 - 1:55 pm. (1 message)

Next thread: Re: iw reg set does not work because udev and crda do not respond to boot-time request. by Luis R. Rodriguez on Saturday, July 31, 2010 - 2:05 pm. (1 message)
[view original message]
From: Ondrej Zary
Subject: [PATCH 3/3] cyber2000fb: add I2C support
Date: Saturday, July 31, 2010 - 1:55 pm

Add I2C support for the DDC bus to cyber2000fb driver. This is only bus
support, driver does not use EDID.
Tested on two different CyberPro 2000 cards with i2cdetect and decode-edid.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>

diff -urp linux-2.6.35-rc3-/drivers/video/cyber2000fb.c linux-2.6.35-rc3/drivers/video/cyber2000fb.c
--- linux-2.6.35-rc3-/drivers/video/cyber2000fb.c	2010-07-31 21:58:35.000000000 +0200
+++ linux-2.6.35-rc3/drivers/video/cyber2000fb.c	2010-07-31 22:49:55.000000000 +0200
@@ -48,6 +48,10 @@
 #include <linux/init.h>
 #include <linux/io.h>
 
+#include <linux/i2c.h>
+#include <linux/i2c-id.h>
+#include <linux/i2c-algo-bit.h>
+
 #include <asm/pgtable.h>
 #include <asm/system.h>
 
@@ -88,6 +92,11 @@ struct cfb_info {
 	u_char			ramdac_powerdown;
 
 	u32			pseudo_palette[16];
+#ifdef CONFIG_FB_CYBER2000_I2C
+	bool			i2c_registered;
+	struct i2c_adapter	i2c_adapter;
+	struct i2c_algo_bit_data	i2c_algo;
+#endif
 };
 
 static char *default_font = "Acorn8x8";
@@ -1145,6 +1154,95 @@ void cyber2000fb_detach(int idx)
 }
 EXPORT_SYMBOL(cyber2000fb_detach);
 
+#ifdef CONFIG_FB_CYBER2000_I2C
+
+#define DDC_REG		0xb0
+#define DDC_SCL_OUT	(1 << 0)
+#define DDC_SDA_OUT	(1 << 4)
+#define DDC_SCL_IN	(1 << 2)
+#define DDC_SDA_IN	(1 << 6)
+
+static void cyber2000fb_enable_ddc(char enable, struct cfb_info *cfb)
+{
+	cyber2000fb_writew(((enable & 0x01) << 8) | 0xbf, 0x3ce, cfb);
+}
+
+static void cyber2000fb_setscl(void *data, int val)
+{
+	struct cfb_info *cfb = data;
+	unsigned char reg;
+
+	cyber2000fb_enable_ddc(1, cfb);
+	reg = cyber2000_grphr(DDC_REG, cfb);
+	if (!val)	/* bit is inverted */
+		reg |= DDC_SCL_OUT;
+	else
+		reg &= ~DDC_SCL_OUT;
+	cyber2000_grphw(DDC_REG, reg, cfb);
+	cyber2000fb_enable_ddc(0, cfb);
+}
+
+static void cyber2000fb_setsda(void *data, int val)
+{
+	struct cfb_info *cfb = data;
+	unsigned char reg;
+
+	cyber2000fb_enable_ddc(1, cfb);
+	reg = cyber2000_grphr(DDC_REG, cfb);
+	if (!val)	/* bit is ...
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From: Russell King - ARM Linux
Subject: Re: [PATCH 3/3] cyber2000fb: add I2C support
Date: Saturday, July 31, 2010 - 2:42 pm

I'm debating a bit about this.

One thing I'm concerned about is switching the DCLK registers to DCC
mode without any protection against mode changes co-inciding with
I2C activity.  On a SMP machine, it's possible for both to happen
simultaneously.

Secondly, please name these I2C bits with 'ddc' in the name - the
CyberPro appear to have more than one I2C bus on them (or can have)
such as for driving SAA7111 video decoders.
--


[ message continues ]
[view original message]
From: Ondrej Zary
Subject: [PATCH 3/3 v2] cyber2000fb: add I2C support
Date: Saturday, July 31, 2010 - 3:13 pm

Add I2C support for the DDC bus to cyber2000fb driver. This is only bus
support, driver does not use EDID.
Tested on two different CyberPro 2000 cards with i2cdetect and decode-edid.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
---
This is v2 with added locking and ddc things properly named.

diff -urp linux-2.6.35-rc3-/drivers/video/cyber2000fb.c linux-2.6.35-rc3/drivers/video/cyber2000fb.c
--- linux-2.6.35-rc3-/drivers/video/cyber2000fb.c	2010-07-31 21:58:35.000000000 +0200
+++ linux-2.6.35-rc3/drivers/video/cyber2000fb.c	2010-08-01 00:02:59.000000000 +0200
@@ -48,6 +48,10 @@
 #include <linux/init.h>
 #include <linux/io.h>
 
+#include <linux/i2c.h>
+#include <linux/i2c-id.h>
+#include <linux/i2c-algo-bit.h>
+
 #include <asm/pgtable.h>
 #include <asm/system.h>
 
@@ -88,6 +92,12 @@ struct cfb_info {
 	u_char			ramdac_powerdown;
 
 	u32			pseudo_palette[16];
+#ifdef CONFIG_FB_CYBER2000_I2C
+	bool			ddc_registered;
+	struct i2c_adapter	ddc_adapter;
+	struct i2c_algo_bit_data	ddc_algo;
+	struct mutex		reg_b0_lock;
+#endif
 };
 
 static char *default_font = "Acorn8x8";
@@ -498,6 +508,9 @@ static void cyber2000fb_set_timing(struc
 	cyber2000_attrw(0x14, 0x00, cfb);
 
 	/* PLL registers */
+#ifdef CONFIG_FB_CYBER2000_I2C
+	mutex_lock(&cfb->reg_b0_lock);
+#endif
 	cyber2000_grphw(EXT_DCLK_MULT, hw->clock_mult, cfb);
 	cyber2000_grphw(EXT_DCLK_DIV, hw->clock_div, cfb);
 	cyber2000_grphw(EXT_MCLK_MULT, cfb->mclk_mult, cfb);
@@ -505,6 +518,9 @@ static void cyber2000fb_set_timing(struc
 	cyber2000_grphw(0x90, 0x01, cfb);
 	cyber2000_grphw(0xb9, 0x80, cfb);
 	cyber2000_grphw(0xb9, 0x00, cfb);
+#ifdef CONFIG_FB_CYBER2000_I2C
+	mutex_unlock(&cfb->reg_b0_lock);
+#endif
 
 	cfb->ramdac_ctrl = hw->ramdac;
 	cyber2000fb_write_ramdac_ctrl(cfb);
@@ -1145,6 +1161,105 @@ void cyber2000fb_detach(int idx)
 }
 EXPORT_SYMBOL(cyber2000fb_detach);
 
+#ifdef CONFIG_FB_CYBER2000_I2C
+
+#define DDC_REG		0xb0
+#define DDC_SCL_OUT	(1 << 0)
+#define DDC_SDA_OUT	(1 << ...
[ message continues ]
[view original message]
From: Russell King - ARM Linux
Subject: Re: [PATCH 3/3 v2] cyber2000fb: add I2C support
Date: Sunday, August 1, 2010 - 1:44 am

Does the weight of a mutex really matter here, or would a spinlock be




cyber2000fb_ddc_getsda
--


[ message continues ]
[view original message]
From: Ondrej Zary
Subject: [PATCH 3/3 v3] cyber2000fb: add I2C support
Date: Sunday, August 1, 2010 - 3:07 am

Add I2C support for the DDC bus to cyber2000fb driver. This is only bus
support, driver does not use EDID.
Tested on two different CyberPro 2000 cards with i2cdetect and decode-edid.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
---
This is v3 with spinlock instead of mutex (I don't know what's better here -
but both mode switch and DDC are not performance critical so it probably does
not matter) and all new things properly named ddc.

diff -urp linux-2.6.35-rc3-/drivers/video/cyber2000fb.c linux-2.6.35-rc3/drivers/video/cyber2000fb.c
--- linux-2.6.35-rc3-/drivers/video/cyber2000fb.c	2010-07-31 21:58:35.000000000 +0200
+++ linux-2.6.35-rc3/drivers/video/cyber2000fb.c	2010-08-01 11:53:32.000000000 +0200
@@ -48,6 +48,10 @@
 #include <linux/init.h>
 #include <linux/io.h>
 
+#include <linux/i2c.h>
+#include <linux/i2c-id.h>
+#include <linux/i2c-algo-bit.h>
+
 #include <asm/pgtable.h>
 #include <asm/system.h>
 
@@ -88,6 +92,12 @@ struct cfb_info {
 	u_char			ramdac_powerdown;
 
 	u32			pseudo_palette[16];
+#ifdef CONFIG_FB_CYBER2000_DDC
+	bool			ddc_registered;
+	struct i2c_adapter	ddc_adapter;
+	struct i2c_algo_bit_data	ddc_algo;
+	spinlock_t		reg_b0_lock;
+#endif
 };
 
 static char *default_font = "Acorn8x8";
@@ -498,6 +508,9 @@ static void cyber2000fb_set_timing(struc
 	cyber2000_attrw(0x14, 0x00, cfb);
 
 	/* PLL registers */
+#ifdef CONFIG_FB_CYBER2000_DDC
+	spin_lock(&cfb->reg_b0_lock);
+#endif
 	cyber2000_grphw(EXT_DCLK_MULT, hw->clock_mult, cfb);
 	cyber2000_grphw(EXT_DCLK_DIV, hw->clock_div, cfb);
 	cyber2000_grphw(EXT_MCLK_MULT, cfb->mclk_mult, cfb);
@@ -505,6 +518,9 @@ static void cyber2000fb_set_timing(struc
 	cyber2000_grphw(0x90, 0x01, cfb);
 	cyber2000_grphw(0xb9, 0x80, cfb);
 	cyber2000_grphw(0xb9, 0x00, cfb);
+#ifdef CONFIG_FB_CYBER2000_DDC
+	spin_unlock(&cfb->reg_b0_lock);
+#endif
 
 	cfb->ramdac_ctrl = hw->ramdac;
 	cyber2000fb_write_ramdac_ctrl(cfb);
@@ -1145,6 +1161,105 @@ void cyber2000fb_detach(int idx)
 }
 ...
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Previous thread: [PATCH 2/3] cyber2000fb: add mode_option parameter by Ondrej Zary on Saturday, July 31, 2010 - 1:55 pm. (1 message)

Next thread: Re: iw reg set does not work because udev and crda do not respond to boot-time request. by Luis R. Rodriguez on Saturday, July 31, 2010 - 2:05 pm. (1 message)