3 files changed, 234 insertions, 1 deletions

diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index ffe2f2796e29..7826bdce4bbe 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -1550,6 +1550,7 @@ config FB_3DFX
         select FB_CFB_IMAGEBLIT
         select FB_CFB_FILLRECT
         select FB_CFB_COPYAREA
+        select FB_MODE_HELPERS
         help
           This driver supports graphics boards with the 3Dfx Banshee,
           Voodoo3 or VSA-100 (aka Voodoo4/5) chips. Say Y if you have
@@ -1565,6 +1566,14 @@ config FB_3DFX_ACCEL
         This will compile the 3Dfx Banshee/Voodoo3/VSA-100 frame buffer
         device driver with acceleration functions.
 
+config FB_3DFX_I2C
+        bool "Enable DDC/I2C support"
+        depends on FB_3DFX && EXPERIMENTAL
+        select FB_DDC
+        default y
+        help
+          Say Y here if you want DDC/I2C support for your 3dfx Voodoo3.
+
 config FB_VOODOO1
         tristate "3Dfx Voodoo Graphics (sst1) support"
         depends on FB && PCI
diff --git a/drivers/video/tdfxfb.c b/drivers/video/tdfxfb.c
index ee64771fbe3d..bc6f916c53be 100644
--- a/drivers/video/tdfxfb.c
+++ b/drivers/video/tdfxfb.c
@@ -10,6 +10,12 @@
  * Created      : Thu Sep 23 18:17:43 1999, hmallat
  * Last modified: Tue Nov  2 21:19:47 1999, hmallat
  *
+ * I2C part copied from the i2c-voodoo3.c driver by:
+ * Frodo Looijaard <frodol@dds.nl>,
+ * Philip Edelbrock <phil@netroedge.com>,
+ * Ralph Metzler <rjkm@thp.uni-koeln.de>, and
+ * Mark D. Studebaker <mdsxyz123@yahoo.com>
+ *
  * Lots of the information here comes from the Daryll Strauss' Banshee
  * patches to the XF86 server, and the rest comes from the 3dfx
  * Banshee specification. I'm very much indebted to Daryll for his
@@ -1167,6 +1173,190 @@ static struct fb_ops tdfxfb_ops = {
 #endif
 };
 
+#ifdef CONFIG_FB_3DFX_I2C
+/* The voo GPIO registers don't have individual masks for each bit
+   so we always have to read before writing. */
+
+static void tdfxfb_i2c_setscl(void *data, int val)
+{
+        struct tdfxfb_i2c_chan  *chan = data;
+        struct tdfx_par         *par = chan->par;
+        unsigned int r;
+
+        r = tdfx_inl(par, VIDSERPARPORT);
+        if (val)
+                r |= I2C_SCL_OUT;
+        else
+                r &= ~I2C_SCL_OUT;
+        tdfx_outl(par, VIDSERPARPORT, r);
+        tdfx_inl(par, VIDSERPARPORT);   /* flush posted write */
+}
+
+static void tdfxfb_i2c_setsda(void *data, int val)
+{
+        struct tdfxfb_i2c_chan  *chan = data;
+        struct tdfx_par         *par = chan->par;
+        unsigned int r;
+
+        r = tdfx_inl(par, VIDSERPARPORT);
+        if (val)
+                r |= I2C_SDA_OUT;
+        else
+                r &= ~I2C_SDA_OUT;
+        tdfx_outl(par, VIDSERPARPORT, r);
+        tdfx_inl(par, VIDSERPARPORT);   /* flush posted write */
+}
+
+/* The GPIO pins are open drain, so the pins always remain outputs.
+   We rely on the i2c-algo-bit routines to set the pins high before
+   reading the input from other chips. */
+
+static int tdfxfb_i2c_getscl(void *data)
+{
+        struct tdfxfb_i2c_chan  *chan = data;
+        struct tdfx_par         *par = chan->par;
+
+        return (0 != (tdfx_inl(par, VIDSERPARPORT) & I2C_SCL_IN));
+}
+
+static int tdfxfb_i2c_getsda(void *data)
+{
+        struct tdfxfb_i2c_chan  *chan = data;
+        struct tdfx_par         *par = chan->par;
+
+        return (0 != (tdfx_inl(par, VIDSERPARPORT) & I2C_SDA_IN));
+}
+
+static void tdfxfb_ddc_setscl(void *data, int val)
+{
+        struct tdfxfb_i2c_chan  *chan = data;
+        struct tdfx_par         *par = chan->par;
+        unsigned int r;
+
+        r = tdfx_inl(par, VIDSERPARPORT);
+        if (val)
+                r |= DDC_SCL_OUT;
+        else
+                r &= ~DDC_SCL_OUT;
+        tdfx_outl(par, VIDSERPARPORT, r);
+        tdfx_inl(par, VIDSERPARPORT);   /* flush posted write */
+}
+
+static void tdfxfb_ddc_setsda(void *data, int val)
+{
+        struct tdfxfb_i2c_chan  *chan = data;
+        struct tdfx_par         *par = chan->par;
+        unsigned int r;
+
+        r = tdfx_inl(par, VIDSERPARPORT);
+        if (val)
+                r |= DDC_SDA_OUT;
+        else
+                r &= ~DDC_SDA_OUT;
+        tdfx_outl(par, VIDSERPARPORT, r);
+        tdfx_inl(par, VIDSERPARPORT);   /* flush posted write */
+}
+
+static int tdfxfb_ddc_getscl(void *data)
+{
+        struct tdfxfb_i2c_chan  *chan = data;
+        struct tdfx_par         *par = chan->par;
+
+        return (0 != (tdfx_inl(par, VIDSERPARPORT) & DDC_SCL_IN));
+}
+
+static int tdfxfb_ddc_getsda(void *data)
+{
+        struct tdfxfb_i2c_chan  *chan = data;
+        struct tdfx_par         *par = chan->par;
+
+        return (0 != (tdfx_inl(par, VIDSERPARPORT) & DDC_SDA_IN));
+}
+
+static int __devinit tdfxfb_setup_ddc_bus(struct tdfxfb_i2c_chan *chan,
+                                          const char *name, struct device *dev)
+{
+        int rc;
+
+        strlcpy(chan->adapter.name, name, sizeof(chan->adapter.name));
+        chan->adapter.owner             = THIS_MODULE;
+        chan->adapter.class             = I2C_CLASS_DDC;
+        chan->adapter.algo_data         = &chan->algo;
+        chan->adapter.dev.parent        = dev;
+        chan->algo.setsda               = tdfxfb_ddc_setsda;
+        chan->algo.setscl               = tdfxfb_ddc_setscl;
+        chan->algo.getsda               = tdfxfb_ddc_getsda;
+        chan->algo.getscl               = tdfxfb_ddc_getscl;
+        chan->algo.udelay               = 10;
+        chan->algo.timeout              = msecs_to_jiffies(500);
+        chan->algo.data                 = chan;
+
+        i2c_set_adapdata(&chan->adapter, chan);
+
+        rc = i2c_bit_add_bus(&chan->adapter);
+        if (rc == 0)
+                DPRINTK("I2C bus %s registered.\n", name);
+        else
+                chan->par = NULL;
+
+        return rc;
+}
+
+static int __devinit tdfxfb_setup_i2c_bus(struct tdfxfb_i2c_chan *chan,
+                                          const char *name, struct device *dev)
+{
+        int rc;
+
+        strlcpy(chan->adapter.name, name, sizeof(chan->adapter.name));
+        chan->adapter.owner             = THIS_MODULE;
+        chan->adapter.class             = I2C_CLASS_TV_ANALOG;
+        chan->adapter.algo_data         = &chan->algo;
+        chan->adapter.dev.parent        = dev;
+        chan->algo.setsda               = tdfxfb_i2c_setsda;
+        chan->algo.setscl               = tdfxfb_i2c_setscl;
+        chan->algo.getsda               = tdfxfb_i2c_getsda;
+        chan->algo.getscl               = tdfxfb_i2c_getscl;
+        chan->algo.udelay               = 10;
+        chan->algo.timeout              = msecs_to_jiffies(500);
+        chan->algo.data                 = chan;
+
+        i2c_set_adapdata(&chan->adapter, chan);
+
+        rc = i2c_bit_add_bus(&chan->adapter);
+        if (rc == 0)
+                DPRINTK("I2C bus %s registered.\n", name);
+        else
+                chan->par = NULL;
+
+        return rc;
+}
+
+static void __devinit tdfxfb_create_i2c_busses(struct fb_info *info)
+{
+        struct tdfx_par *par = info->par;
+
+        tdfx_outl(par, VIDINFORMAT, 0x8160);
+        tdfx_outl(par, VIDSERPARPORT, 0xcffc0020);
+
+        par->chan[0].par = par;
+        par->chan[1].par = par;
+
+        tdfxfb_setup_ddc_bus(&par->chan[0], "Voodoo3-DDC", info->dev);
+        tdfxfb_setup_i2c_bus(&par->chan[1], "Voodoo3-I2C", info->dev);
+}
+
+static void tdfxfb_delete_i2c_busses(struct tdfx_par *par)
+{
+        if (par->chan[0].par)
+                i2c_del_adapter(&par->chan[0].adapter);
+        par->chan[0].par = NULL;
+
+        if (par->chan[1].par)
+                i2c_del_adapter(&par->chan[1].adapter);
+        par->chan[1].par = NULL;
+}
+#endif /* CONFIG_FB_3DFX_I2C */
+
 /**
  *      tdfxfb_probe - Device Initializiation
  *
@@ -1284,7 +1474,9 @@ static int __devinit tdfxfb_probe(struct pci_dev *pdev,
         if (hwcursor)
                 info->fix.smem_len = (info->fix.smem_len - 1024) &
                                         (PAGE_MASK << 1);
-
+#ifdef CONFIG_FB_3DFX_I2C
+        tdfxfb_create_i2c_busses(info);
+#endif
         if (!mode_option)
                 mode_option = "640x480@60";
 
@@ -1315,6 +1507,9 @@ static int __devinit tdfxfb_probe(struct pci_dev *pdev,
         return 0;
 
 out_err_iobase:
+#ifdef CONFIG_FB_3DFX_I2C
+        tdfxfb_delete_i2c_busses(default_par);
+#endif
         if (default_par->mtrr_handle >= 0)
                 mtrr_del(default_par->mtrr_handle, info->fix.smem_start,
                          info->fix.smem_len);
@@ -1379,6 +1574,9 @@ static void __devexit tdfxfb_remove(struct pci_dev *pdev)
         struct tdfx_par *par = info->par;
 
         unregister_framebuffer(info);
+#ifdef CONFIG_FB_3DFX_I2C
+        tdfxfb_delete_i2c_busses(par);
+#endif
         if (par->mtrr_handle >= 0)
                 mtrr_del(par->mtrr_handle, info->fix.smem_start,
                          info->fix.smem_len);
diff --git a/include/video/tdfx.h b/include/video/tdfx.h
index 7431d9681e57..befbaf0a92d8 100644
--- a/include/video/tdfx.h
+++ b/include/video/tdfx.h
@@ -1,6 +1,9 @@
 #ifndef _TDFX_H
 #define _TDFX_H
 
+#include <linux/i2c.h>
+#include <linux/i2c-algo-bit.h>
+
 /* membase0 register offsets */
 #define STATUS          0x00
 #define PCIINIT0        0x04
@@ -123,6 +126,18 @@
 #define VIDCFG_PIXFMT_SHIFT             18
 #define DACMODE_2X                      BIT(0)
 
+/* I2C bit locations in the VIDSERPARPORT register */
+#define DDC_ENAB        0x00040000
+#define DDC_SCL_OUT     0x00080000
+#define DDC_SDA_OUT     0x00100000
+#define DDC_SCL_IN      0x00200000
+#define DDC_SDA_IN      0x00400000
+#define I2C_ENAB        0x00800000
+#define I2C_SCL_OUT     0x01000000
+#define I2C_SDA_OUT     0x02000000
+#define I2C_SCL_IN      0x04000000
+#define I2C_SDA_IN      0x08000000
+
 /* VGA rubbish, need to change this for multihead support */
 #define MISC_W          0x3c2
 #define MISC_R          0x3cc
@@ -168,12 +183,23 @@ struct banshee_reg {
         unsigned long miscinit0;
 };
 
+struct tdfx_par;
+
+struct tdfxfb_i2c_chan {
+        struct tdfx_par *par;
+        struct i2c_adapter adapter;
+        struct i2c_algo_bit_data algo;
+};
+
 struct tdfx_par {
         u32 max_pixclock;
         u32 palette[16];
         void __iomem *regbase_virt;
         unsigned long iobase;
         int mtrr_handle;
+#ifdef CONFIG_FB_3DFX_I2C
+        struct tdfxfb_i2c_chan chan[2];
+#endif
 };
 
 #endif  /* __KERNEL__ */