+#define DDC_SDA_TGUI BIT(0)
+#define DDC_SCL_TGUI BIT(1)
+#define DDC_SCL_DRIVE_TGUI BIT(2)
+#define DDC_SDA_DRIVE_TGUI BIT(3)
+#define DDC_MASK_TGUI (DDC_SCL_DRIVE_TGUI | DDC_SDA_DRIVE_TGUI)
+
+static void tridentfb_ddc_setscl_tgui(void *data, int val)
+{
+ struct tridentfb_par *par = data;
+ u8 reg = vga_mm_rcrt(par->io_virt, I2C) & DDC_MASK_TGUI;
+
+ if (val)
+ reg &= ~DDC_SCL_DRIVE_TGUI; /* disable drive - don't drive hi */
+ else
+ reg |= DDC_SCL_DRIVE_TGUI; /* drive low */
+
+ vga_mm_wcrt(par->io_virt, I2C, reg);
+}
+
+static void tridentfb_ddc_setsda_tgui(void *data, int val)
+{
+ struct tridentfb_par *par = data;
+ u8 reg = vga_mm_rcrt(par->io_virt, I2C) & DDC_MASK_TGUI;
+
+ if (val)
+ reg &= ~DDC_SDA_DRIVE_TGUI; /* disable drive - don't drive hi */
+ else
+ reg |= DDC_SDA_DRIVE_TGUI; /* drive low */
+
+ vga_mm_wcrt(par->io_virt, I2C, reg);
+}
+
+static int tridentfb_ddc_getsda_tgui(void *data)
+{
+ struct tridentfb_par *par = data;
+
+ return !!(vga_mm_rcrt(par->io_virt, I2C) & DDC_SDA_TGUI);
+}
+
+#define DDC_SDA_IN BIT(0)
+#define DDC_SCL_OUT BIT(1)
+#define DDC_SDA_OUT BIT(3)
+#define DDC_SCL_IN BIT(6)
+#define DDC_MASK (DDC_SCL_OUT | DDC_SDA_OUT)
+
+static void tridentfb_ddc_setscl(void *data, int val)
+{
+ struct tridentfb_par *par = data;
+ unsigned char reg;
+
+ reg = vga_mm_rcrt(par->io_virt, I2C) & DDC_MASK;
+ if (val)
+ reg |= DDC_SCL_OUT;
+ else
+ reg &= ~DDC_SCL_OUT;
+ vga_mm_wcrt(par->io_virt, I2C, reg);
+}
+
+static void tridentfb_ddc_setsda(void *data, int val)
+{
+ struct tridentfb_par *par = data;
+ unsigned char reg;
+
+ reg = vga_mm_rcrt(par->io_virt, I2C) & DDC_MASK;
+ if (!val)
+ reg |= DDC_SDA_OUT;
+ else
+ reg &= ~DDC_SDA_OUT;
+ vga_mm_wcrt(par->io_virt, I2C, reg);
+}
+
+static int tridentfb_ddc_getscl(void *data)
+{
+ struct tridentfb_par *par = data;
+
+ return !!(vga_mm_rcrt(par->io_virt, I2C) & DDC_SCL_IN);
+}
+
+static int tridentfb_ddc_getsda(void *data)
+{
+ struct tridentfb_par *par = data;
+
+ return !!(vga_mm_rcrt(par->io_virt, I2C) & DDC_SDA_IN);
+}
+
+static int tridentfb_setup_ddc_bus(struct fb_info *info)
+{
+ struct tridentfb_par *par = info->par;
+
+ strlcpy(par->ddc_adapter.name, info->fix.id,
+ sizeof(par->ddc_adapter.name));
+ par->ddc_adapter.owner = THIS_MODULE;
+ par->ddc_adapter.class = I2C_CLASS_DDC;
+ par->ddc_adapter.algo_data = &par->ddc_algo;
+ par->ddc_adapter.dev.parent = info->device;
+ if (is_oldclock(par->chip_id)) { /* not sure if this check is OK */
+ par->ddc_algo.setsda = tridentfb_ddc_setsda_tgui;
+ par->ddc_algo.setscl = tridentfb_ddc_setscl_tgui;
+ par->ddc_algo.getsda = tridentfb_ddc_getsda_tgui;
+ /* no getscl */
+ } else {
+ par->ddc_algo.setsda = tridentfb_ddc_setsda;
+ par->ddc_algo.setscl = tridentfb_ddc_setscl;
+ par->ddc_algo.getsda = tridentfb_ddc_getsda;
+ par->ddc_algo.getscl = tridentfb_ddc_getscl;
+ }
+ par->ddc_algo.udelay = 10;
+ par->ddc_algo.timeout = 20;
+ par->ddc_algo.data = par;
+
+ i2c_set_adapdata(&par->ddc_adapter, par);
+
+ return i2c_bit_add_bus(&par->ddc_adapter);
+}
+