intelfb: add preliminary i2c support

[06/07] intelfb: adds intelfb_i2c.c which contains the infrastructure needed to
enumerate the i2c busses on the intelfb.
Signed-off-by: Dennis Munsie <dmunsie@cecropia.com>

drivers/video/intelfb/intelfb.h

@@ -365,4 +365,8 @@ struct intelfb_info {
 
 extern int intelfb_var_to_depth(const struct fb_var_screeninfo *var);
 
+#ifdef CONFIG_FB_INTEL_I2C
+extern void intelfb_create_i2c_busses(struct intelfb_info *dinfo);
+#endif
+
 #endif /* _INTELFB_H */

drivers/video/intelfb/intelfb_i2c.c

+/**************************************************************************
+
+ Copyright 2006 Dave Airlie <airlied@linux.ie>
+
+All Rights Reserved.
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the "Software"),
+to deal in the Software without restriction, including without limitation
+on the rights to use, copy, modify, merge, publish, distribute, sub
+license, and/or sell copies of the Software, and to permit persons to whom
+the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice (including the next
+paragraph) shall be included in all copies or substantial portions of the
+Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+THE COPYRIGHT HOLDERS AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+**************************************************************************/
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/pci.h>
+#include <linux/fb.h>
+
+#include <linux/i2c.h>
+#include <linux/i2c-id.h>
+#include <linux/i2c-algo-bit.h>
+
+#include <asm/io.h>
+
+#include "intelfb.h"
+#include "intelfbhw.h"
+
+/* bit locations in the registers */
+#define SCL_DIR_MASK		0x0001
+#define SCL_DIR			0x0002
+#define SCL_VAL_MASK		0x0004
+#define SCL_VAL_OUT		0x0008
+#define SCL_VAL_IN		0x0010
+#define SDA_DIR_MASK		0x0100
+#define SDA_DIR			0x0200
+#define SDA_VAL_MASK		0x0400
+#define SDA_VAL_OUT		0x0800
+#define SDA_VAL_IN		0x1000
+
+static void intelfb_gpio_setscl(void *data, int state)
+{
+	struct intelfb_i2c_chan *chan = data;
+	struct intelfb_info *dinfo = chan->dinfo;
+	u32 val;
+
+	OUTREG(chan->reg, (state ? SCL_VAL_OUT : 0) | SCL_DIR | SCL_DIR_MASK | SCL_VAL_MASK);
+	val = INREG(chan->reg);
+}
+
+static void intelfb_gpio_setsda(void *data, int state)
+{
+	struct intelfb_i2c_chan *chan = data;
+	struct intelfb_info *dinfo = chan->dinfo;
+	u32 val;
+
+	OUTREG(chan->reg, (state ? SDA_VAL_OUT : 0) | SDA_DIR | SDA_DIR_MASK | SDA_VAL_MASK);
+	val = INREG(chan->reg);
+}
+
+static int intelfb_gpio_getscl(void *data)
+{
+	struct intelfb_i2c_chan *chan = data;
+	struct intelfb_info *dinfo = chan->dinfo;
+	u32 val;
+
+	OUTREG(chan->reg, SCL_DIR_MASK);
+	OUTREG(chan->reg, 0);
+	val = INREG(chan->reg);
+	return ((val & SCL_VAL_IN) != 0);
+}
+
+static int intelfb_gpio_getsda(void *data)
+{
+	struct intelfb_i2c_chan *chan = data;
+	struct intelfb_info *dinfo = chan->dinfo;
+	u32 val;
+
+	OUTREG(chan->reg, SDA_DIR_MASK);
+	OUTREG(chan->reg, 0);
+	val = INREG(chan->reg);
+	return ((val & SDA_VAL_IN) != 0);
+}
+
+static int intelfb_setup_i2c_bus(struct intelfb_info *dinfo,
+								 struct intelfb_i2c_chan *chan,
+								 const u32 reg, const char *name)
+{
+	int rc;
+
+	chan->dinfo					= dinfo;
+	chan->reg					= reg;
+	snprintf(chan->adapter.name, I2C_NAME_SIZE, "intelfb %s", name);
+	chan->adapter.owner			= THIS_MODULE;
+	chan->adapter.id			= I2C_HW_B_INTELFB;
+	chan->adapter.algo_data		= &chan->algo;
+	chan->adapter.dev.parent	= &chan->dinfo->pdev->dev;
+	chan->algo.setsda			= intelfb_gpio_setsda;
+	chan->algo.setscl			= intelfb_gpio_setscl;
+	chan->algo.getsda			= intelfb_gpio_getsda;
+	chan->algo.getscl			= intelfb_gpio_getscl;
+	chan->algo.udelay			= 40;
+	chan->algo.timeout			= 20;
+	chan->algo.data				= chan;
+
+	i2c_set_adapdata(&chan->adapter, chan);
+
+	/* Raise SCL and SDA */
+	intelfb_gpio_setsda(chan, 1);
+	intelfb_gpio_setscl(chan, 1);
+	udelay(20);
+
+	rc = i2c_bit_add_bus(&chan->adapter);
+	if (rc == 0)
+		DBG_MSG("I2C bus %s registered.\n", name);
+	else
+		WRN_MSG("Failed to register I2C bus %s.\n", name);
+	return rc;
+}
+
+void intelfb_create_i2c_busses(struct intelfb_info *dinfo)
+{
+	int i = 0;
+
+	/* everyone has at least a single analog output */
+	dinfo->num_outputs = 1;
+	dinfo->output[i].type = INTELFB_OUTPUT_ANALOG;
+
+	/* setup the DDC bus for analog output */
+	intelfb_setup_i2c_bus(dinfo, &dinfo->output[i].ddc_bus, GPIOA, "CRTDDC_A");
+	i++;
+
+    /* need to add the output busses for each device
+       - this function is very incomplete
+       - i915GM has LVDS and TVOUT for example
+    */
+    switch(dinfo->chipset) {
+	case INTEL_830M:
+	case INTEL_845G:
+	case INTEL_855GM:
+	case INTEL_865G:
+		dinfo->output[i].type = INTELFB_OUTPUT_DVO;
+		intelfb_setup_i2c_bus(dinfo, &dinfo->output[i].ddc_bus, GPIOD, "DVODDC_D");
+		intelfb_setup_i2c_bus(dinfo, &dinfo->output[i].i2c_bus, GPIOE, "DVOI2C_E");
+		i++;
+		break;
+	case INTEL_915G:
+	case INTEL_915GM:
+		/* has  some LVDS + tv-out */
+	case INTEL_945G:
+	case INTEL_945GM:
+		/* SDVO ports have a single control bus - 2 devices */
+		dinfo->output[i].type = INTELFB_OUTPUT_SDVO;
+		intelfb_setup_i2c_bus(dinfo, &dinfo->output[i].i2c_bus, GPIOE, "SDVOCTRL_E");
+		/* TODO: initialize the SDVO */
+//		I830SDVOInit(pScrn, i, DVOB);
+		i++;
+
+		/* set up SDVOC */
+		dinfo->output[i].type = INTELFB_OUTPUT_SDVO;
+		dinfo->output[i].i2c_bus = dinfo->output[i - 1].i2c_bus;
+		/* TODO: initialize the SDVO */
+//		I830SDVOInit(pScrn, i, DVOC);
+		i++;
+		break;
+	}
+	dinfo->num_outputs = i;
+}

drivers/video/intelfb/intelfbdrv.c

@@ -851,6 +851,11 @@ intelfb_pci_register(struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (bailearly == 5)
 		bailout(dinfo);
 
+#ifdef CONFIG_FB_INTEL_I2C
+	/* register I2C bus */
+	intelfb_create_i2c_busses(dinfo);
+#endif
+
 	if (bailearly == 6)
 		bailout(dinfo);