drm/gma500: add support for atom e6xx lpc lvds i2c

add gpio bitbanging i2c adapter on LPC device of atom e6xx
gpu chipset to access lvds EDID
tested on SECO QuadMo747-E6xx-EXTREME Qseven platform

Reviewed-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Signed-off-by: Jan Safrata <jan.nikitenko@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

6 files changed, 214 insertions, 12 deletions

diff --git a/drivers/gpu/drm/gma500/Makefile b/drivers/gpu/drm/gma500/Makefile
index b15315576376..190e55f2f891 100644
--- a/drivers/gpu/drm/gma500/Makefile
+++ b/drivers/gpu/drm/gma500/Makefile
@@ -39,6 +39,7 @@ gma500_gfx-$(CONFIG_DRM_GMA3600) +=  cdv_device.o \
 gma500_gfx-$(CONFIG_DRM_GMA600) += oaktrail_device.o \
           oaktrail_crtc.o \
           oaktrail_lvds.o \
+          oaktrail_lvds_i2c.o \
           oaktrail_hdmi.o \
           oaktrail_hdmi_i2c.o
 
diff --git a/drivers/gpu/drm/gma500/oaktrail_lvds.c b/drivers/gpu/drm/gma500/oaktrail_lvds.c
index 0d39da6e8b7a..83bbc271bcfb 100644
--- a/drivers/gpu/drm/gma500/oaktrail_lvds.c
+++ b/drivers/gpu/drm/gma500/oaktrail_lvds.c
@@ -359,22 +359,26 @@ void oaktrail_lvds_init(struct drm_device *dev,
          *    if closed, act like it's not there for now
          */
 
+        edid = NULL;
         mutex_lock(&dev->mode_config.mutex);
         i2c_adap = i2c_get_adapter(dev_priv->ops->i2c_bus);
-        if (i2c_adap == NULL)
-                dev_err(dev->dev, "No ddc adapter available!\n");
+        if (i2c_adap)
+                edid = drm_get_edid(connector, i2c_adap);
+        if (edid == NULL && dev_priv->lpc_gpio_base) {
+                oaktrail_lvds_i2c_init(encoder);
+                if (gma_encoder->ddc_bus != NULL) {
+                        i2c_adap = &gma_encoder->ddc_bus->adapter;
+                        edid = drm_get_edid(connector, i2c_adap);
+                }
+        }
         /*
          * Attempt to get the fixed panel mode from DDC.  Assume that the
          * preferred mode is the right one.
          */
-        if (i2c_adap) {
-                edid = drm_get_edid(connector, i2c_adap);
-                if (edid) {
-                        drm_mode_connector_update_edid_property(connector,
-                                                                        edid);
-                        drm_add_edid_modes(connector, edid);
-                        kfree(edid);
-                }
+        if (edid) {
+                drm_mode_connector_update_edid_property(connector, edid);
+                drm_add_edid_modes(connector, edid);
+                kfree(edid);
 
                 list_for_each_entry(scan, &connector->probed_modes, head) {
                         if (scan->type & DRM_MODE_TYPE_PREFERRED) {
@@ -383,7 +387,8 @@ void oaktrail_lvds_init(struct drm_device *dev,
                                 goto out;       /* FIXME: check for quirks */
                         }
                 }
-        }
+        } else
+                dev_err(dev->dev, "No ddc adapter available!\n");
         /*
          * If we didn't get EDID, try geting panel timing
          * from configuration data
@@ -411,8 +416,10 @@ failed_find:
         mutex_unlock(&dev->mode_config.mutex);
 
         dev_dbg(dev->dev, "No LVDS modes found, disabling.\n");
-        if (gma_encoder->ddc_bus)
+        if (gma_encoder->ddc_bus) {
                 psb_intel_i2c_destroy(gma_encoder->ddc_bus);
+                gma_encoder->ddc_bus = NULL;
+        }
 
 /* failed_ddc: */
 
diff --git a/drivers/gpu/drm/gma500/oaktrail_lvds_i2c.c b/drivers/gpu/drm/gma500/oaktrail_lvds_i2c.c
new file mode 100644
index 000000000000..f913a62eee5f
--- /dev/null
+++ b/drivers/gpu/drm/gma500/oaktrail_lvds_i2c.c
@@ -0,0 +1,170 @@
+/*
+ * Copyright (c) 2002-2010, Intel Corporation.
+ * Copyright (c) 2014 ATRON electronic GmbH
+ *   Author: Jan Safrata <jan.nikitenko@gmail.com>
+ *
+ * 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 the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, 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 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 NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS 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/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/types.h>
+#include <linux/i2c.h>
+#include <linux/i2c-algo-bit.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+
+#include <drm/drmP.h>
+#include "psb_drv.h"
+#include "psb_intel_reg.h"
+
+
+/*
+ * LPC GPIO based I2C bus for LVDS of Atom E6xx
+ */
+
+/*-----------------------------------------------------------------------------
+ * LPC Register Offsets. Used for LVDS GPIO Bit Bashing. Registers are part
+ * Atom E6xx [D31:F0]
+ ----------------------------------------------------------------------------*/
+#define RGEN    0x20
+#define RGIO    0x24
+#define RGLVL   0x28
+#define RGTPE   0x2C
+#define RGTNE   0x30
+#define RGGPE   0x34
+#define RGSMI   0x38
+#define RGTS    0x3C
+
+/* The LVDS GPIO clock lines are GPIOSUS[3]
+ * The LVDS GPIO data lines are GPIOSUS[4]
+ */
+#define GPIO_CLOCK      0x08
+#define GPIO_DATA       0x10
+
+#define LPC_READ_REG(chan, r) inl((chan)->reg + (r))
+#define LPC_WRITE_REG(chan, r, val) outl((val), (chan)->reg + (r))
+
+static int get_clock(void *data)
+{
+        struct psb_intel_i2c_chan *chan = data;
+        u32 val, tmp;
+
+        val = LPC_READ_REG(chan, RGIO);
+        val |= GPIO_CLOCK;
+        LPC_WRITE_REG(chan, RGIO, val);
+        tmp = LPC_READ_REG(chan, RGLVL);
+        val = (LPC_READ_REG(chan, RGLVL) & GPIO_CLOCK) ? 1 : 0;
+
+        return val;
+}
+
+static int get_data(void *data)
+{
+        struct psb_intel_i2c_chan *chan = data;
+        u32 val, tmp;
+
+        val = LPC_READ_REG(chan, RGIO);
+        val |= GPIO_DATA;
+        LPC_WRITE_REG(chan, RGIO, val);
+        tmp = LPC_READ_REG(chan, RGLVL);
+        val = (LPC_READ_REG(chan, RGLVL) & GPIO_DATA) ? 1 : 0;
+
+        return val;
+}
+
+static void set_clock(void *data, int state_high)
+{
+        struct psb_intel_i2c_chan *chan = data;
+        u32 val;
+
+        if (state_high) {
+                val = LPC_READ_REG(chan, RGIO);
+                val |= GPIO_CLOCK;
+                LPC_WRITE_REG(chan, RGIO, val);
+        } else {
+                val = LPC_READ_REG(chan, RGIO);
+                val &= ~GPIO_CLOCK;
+                LPC_WRITE_REG(chan, RGIO, val);
+                val = LPC_READ_REG(chan, RGLVL);
+                val &= ~GPIO_CLOCK;
+                LPC_WRITE_REG(chan, RGLVL, val);
+        }
+}
+
+static void set_data(void *data, int state_high)
+{
+        struct psb_intel_i2c_chan *chan = data;
+        u32 val;
+
+        if (state_high) {
+                val = LPC_READ_REG(chan, RGIO);
+                val |= GPIO_DATA;
+                LPC_WRITE_REG(chan, RGIO, val);
+        } else {
+                val = LPC_READ_REG(chan, RGIO);
+                val &= ~GPIO_DATA;
+                LPC_WRITE_REG(chan, RGIO, val);
+                val = LPC_READ_REG(chan, RGLVL);
+                val &= ~GPIO_DATA;
+                LPC_WRITE_REG(chan, RGLVL, val);
+        }
+}
+
+void oaktrail_lvds_i2c_init(struct drm_encoder *encoder)
+{
+        struct drm_device *dev = encoder->dev;
+        struct gma_encoder *gma_encoder = to_gma_encoder(encoder);
+        struct drm_psb_private *dev_priv = dev->dev_private;
+        struct psb_intel_i2c_chan *chan;
+
+        chan = kzalloc(sizeof(struct psb_intel_i2c_chan), GFP_KERNEL);
+        if (!chan)
+                return;
+
+        chan->drm_dev = dev;
+        chan->reg = dev_priv->lpc_gpio_base;
+        strncpy(chan->adapter.name, "gma500 LPC",  I2C_NAME_SIZE - 1);
+        chan->adapter.owner = THIS_MODULE;
+        chan->adapter.algo_data = &chan->algo;
+        chan->adapter.dev.parent = &dev->pdev->dev;
+        chan->algo.setsda = set_data;
+        chan->algo.setscl = set_clock;
+        chan->algo.getsda = get_data;
+        chan->algo.getscl = get_clock;
+        chan->algo.udelay = 100;
+        chan->algo.timeout = usecs_to_jiffies(2200);
+        chan->algo.data = chan;
+
+        i2c_set_adapdata(&chan->adapter, chan);
+
+        set_data(chan, 1);
+        set_clock(chan, 1);
+        udelay(50);
+
+        if (i2c_bit_add_bus(&chan->adapter)) {
+                kfree(chan);
+                return;
+        }
+
+        gma_encoder->ddc_bus = chan;
+}
diff --git a/drivers/gpu/drm/gma500/psb_drv.c b/drivers/gpu/drm/gma500/psb_drv.c
index 6ec3a905fdd2..92e7e5795398 100644
--- a/drivers/gpu/drm/gma500/psb_drv.c
+++ b/drivers/gpu/drm/gma500/psb_drv.c
@@ -212,6 +212,8 @@ static int psb_driver_unload(struct drm_device *dev)
                 }
                 if (dev_priv->aux_pdev)
                         pci_dev_put(dev_priv->aux_pdev);
+                if (dev_priv->lpc_pdev)
+                        pci_dev_put(dev_priv->lpc_pdev);
 
                 /* Destroy VBT data */
                 psb_intel_destroy_bios(dev);
@@ -280,6 +282,24 @@ static int psb_driver_load(struct drm_device *dev, unsigned long flags)
                         DRM_DEBUG_KMS("Couldn't find aux pci device");
                 }
                 dev_priv->gmbus_reg = dev_priv->aux_reg;
+
+                dev_priv->lpc_pdev = pci_get_bus_and_slot(0, PCI_DEVFN(31, 0));
+                if (dev_priv->lpc_pdev) {
+                        pci_read_config_word(dev_priv->lpc_pdev, PSB_LPC_GBA,
+                                &dev_priv->lpc_gpio_base);
+                        pci_write_config_dword(dev_priv->lpc_pdev, PSB_LPC_GBA,
+                                (u32)dev_priv->lpc_gpio_base | (1L<<31));
+                        pci_read_config_word(dev_priv->lpc_pdev, PSB_LPC_GBA,
+                                &dev_priv->lpc_gpio_base);
+                        dev_priv->lpc_gpio_base &= 0xffc0;
+                        if (dev_priv->lpc_gpio_base)
+                                DRM_DEBUG_KMS("Found LPC GPIO at 0x%04x\n",
+                                                dev_priv->lpc_gpio_base);
+                        else {
+                                pci_dev_put(dev_priv->lpc_pdev);
+                                dev_priv->lpc_pdev = NULL;
+                        }
+                }
         } else {
                 dev_priv->gmbus_reg = dev_priv->vdc_reg;
         }
diff --git a/drivers/gpu/drm/gma500/psb_drv.h b/drivers/gpu/drm/gma500/psb_drv.h
index 55ebe2bd88dd..e38057b91865 100644
--- a/drivers/gpu/drm/gma500/psb_drv.h
+++ b/drivers/gpu/drm/gma500/psb_drv.h
@@ -83,6 +83,7 @@ enum {
 #define PSB_PGETBL_CTL           0x2020
 #define _PSB_PGETBL_ENABLED      0x00000001
 #define PSB_SGX_2D_SLAVE_PORT    0x4000
+#define PSB_LPC_GBA              0x44
 
 /* TODO: To get rid of */
 #define PSB_TT_PRIV0_LIMIT       (256*1024*1024)
@@ -441,6 +442,7 @@ struct psb_ops;
 struct drm_psb_private {
         struct drm_device *dev;
         struct pci_dev *aux_pdev; /* Currently only used by mrst */
+        struct pci_dev *lpc_pdev; /* Currently only used by mrst */
         const struct psb_ops *ops;
         const struct psb_offset *regmap;
         
@@ -470,6 +472,7 @@ struct drm_psb_private {
         uint8_t __iomem *sgx_reg;
         uint8_t __iomem *vdc_reg;
         uint8_t __iomem *aux_reg; /* Auxillary vdc pipe regs */
+        uint16_t lpc_gpio_base;
         uint32_t gatt_free_offset;
 
         /* Fencing / irq */
diff --git a/drivers/gpu/drm/gma500/psb_intel_drv.h b/drivers/gpu/drm/gma500/psb_intel_drv.h
index 336bd3aa1a06..860dd2177ca1 100644
--- a/drivers/gpu/drm/gma500/psb_intel_drv.h
+++ b/drivers/gpu/drm/gma500/psb_intel_drv.h
@@ -223,6 +223,7 @@ extern void oaktrail_lvds_init(struct drm_device *dev,
 extern void oaktrail_wait_for_INTR_PKT_SENT(struct drm_device *dev);
 extern void oaktrail_dsi_init(struct drm_device *dev,
                            struct psb_intel_mode_device *mode_dev);
+extern void oaktrail_lvds_i2c_init(struct drm_encoder *encoder);
 extern void mid_dsi_init(struct drm_device *dev,
                     struct psb_intel_mode_device *mode_dev, int dsi_num);