[Intel-gfx] [PATCH 2/2] drm/i915: Add generic i2c mipi parsing

[Vandana Kannan]

From: vkorjani <vikas.korjani at intel.com>

The VBT now contains i2c sequences to allow the graphics driver to
bring up the device by directly writing to any devices that need to be
programmed.

Signed-off-by: vkorjani <vikas.korjani at intel.com>
Signed-off-by: Nabendu Maiti <nabendu.bikash.maiti at intel.com>
Signed-off-by: Deepak M <m.deepak at intel.com>
Signed-off-by: Rafael Barbalho <rafael.barbalho at intel.com>
---
 drivers/gpu/drm/i915/intel_bios.c          |  2 +-
 drivers/gpu/drm/i915/intel_dsi.c           |  3 ++
 drivers/gpu/drm/i915/intel_dsi.h           |  2 +
 drivers/gpu/drm/i915/intel_dsi_panel_vbt.c | 75 +++++++++++++++++++++++++++++-
 4 files changed, 80 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index c27cc6d..bb50c1a 100644
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -712,7 +712,7 @@ static u8 *goto_next_sequence(u8 *data, int *size)
 			break;
 		case MIPI_SEQ_ELEM_I2C:
 			/* skip by this element payload size */
-			data += 6;
+			data += 7;
 			len = *data;
 			data += len + 1;
 			break;
diff --git a/drivers/gpu/drm/i915/intel_dsi.c b/drivers/gpu/drm/i915/intel_dsi.c
index 0b18407..193ac18 100644
--- a/drivers/gpu/drm/i915/intel_dsi.c
+++ b/drivers/gpu/drm/i915/intel_dsi.c
@@ -155,6 +155,9 @@ static void intel_dsi_enable(struct intel_encoder *encoder)
 		if (intel_dsi->dev.dev_ops->enable)
 			intel_dsi->dev.dev_ops->enable(&intel_dsi->dev);
 
+		if (intel_dsi->dev.dev_ops->enable_backlight)
+			intel_dsi->dev.dev_ops->enable_backlight(&intel_dsi->dev);
+
 		wait_for_dsi_fifo_empty(intel_dsi);
 
 		/* assert ip_tg_enable signal */
diff --git a/drivers/gpu/drm/i915/intel_dsi.h b/drivers/gpu/drm/i915/intel_dsi.h
index 657eb5c..493bd22 100644
--- a/drivers/gpu/drm/i915/intel_dsi.h
+++ b/drivers/gpu/drm/i915/intel_dsi.h
@@ -51,6 +51,8 @@ struct intel_dsi_dev_ops {
 	/* This callback must be able to assume DSI commands can be sent */
 	void (*disable)(struct intel_dsi_device *dsi);
 
+	void (*enable_backlight)(struct intel_dsi_device *dsi);
+
 	int (*mode_valid)(struct intel_dsi_device *dsi,
 			  struct drm_display_mode *mode);
 
diff --git a/drivers/gpu/drm/i915/intel_dsi_panel_vbt.c b/drivers/gpu/drm/i915/intel_dsi_panel_vbt.c
index f6bdd44..25c05b7 100644
--- a/drivers/gpu/drm/i915/intel_dsi_panel_vbt.c
+++ b/drivers/gpu/drm/i915/intel_dsi_panel_vbt.c
@@ -30,6 +30,7 @@
 #include <drm/i915_drm.h>
 #include <linux/slab.h>
 #include <video/mipi_display.h>
+#include <linux/i2c.h>
 #include <asm/intel-mid.h>
 #include <video/mipi_display.h>
 #include "i915_drv.h"
@@ -193,12 +194,70 @@ static u8 *mipi_exec_gpio(struct intel_dsi *intel_dsi, u8 *data)
 	return data;
 }
 
+static u8 *mipi_exec_i2c(struct intel_dsi *intel_dsi, u8 *data)
+{
+	struct i2c_adapter *adapter;
+	int ret;
+	u8 reg_offset, payload_size, retries = 5;
+	struct i2c_msg msg;
+	u8 *transmit_buffer = NULL;
+
+	u8 flag = *data++;
+	u8 index = *data++;
+	u8 bus_number = *data++;
+	u16 slave_add = *(u16 *)(data);
+	data = data + 2;
+	reg_offset = *data++;
+	payload_size = *data++;
+
+	adapter = i2c_get_adapter(bus_number);
+
+	if (!adapter) {
+		DRM_ERROR("i2c_get_adapter(%u) failed, index:%u flag: %u\n",
+				(bus_number + 1), index, flag);
+		goto out;
+	}
+
+	transmit_buffer = kmalloc(1 + payload_size, GFP_TEMPORARY);
+
+	if (!transmit_buffer)
+		goto out;
+
+	transmit_buffer[0] = reg_offset;
+	memcpy(&transmit_buffer[1], data, (size_t)payload_size);
+
+	msg.addr   = slave_add;
+	msg.flags  = 0;
+	msg.len    = 2;
+	msg.buf    = &transmit_buffer[0];
+
+	do {
+		ret =  i2c_transfer(adapter, &msg, 1);
+		if (ret == -EAGAIN)
+			usleep_range(1000, 2500);
+		else if (ret != 1) {
+			DRM_ERROR("i2c transfer failed %d\n", ret);
+			break;
+		}
+	} while (retries--);
+
+	if (retries == 0)
+		DRM_ERROR("i2c transfer failed");
+
+out:
+	kfree(transmit_buffer);
+
+	data = data + payload_size;
+	return data;
+}
+
 typedef u8 * (*fn_mipi_elem_exec)(struct intel_dsi *intel_dsi, u8 *data);
 static const fn_mipi_elem_exec exec_elem[] = {
 	NULL, /* reserved */
 	mipi_exec_send_packet,
 	mipi_exec_delay,
 	mipi_exec_gpio,
+	mipi_exec_i2c,
 	NULL, /* status read; later */
 };
 
@@ -214,7 +273,10 @@ static const char * const seq_name[] = {
 	"MIPI_SEQ_INIT_OTP",
 	"MIPI_SEQ_DISPLAY_ON",
 	"MIPI_SEQ_DISPLAY_OFF",
-	"MIPI_SEQ_DEASSERT_RESET"
+	"MIPI_SEQ_DEASSERT_RESET",
+	"MIPI_BACKLIGHT_ON",
+	"MIPI_BACKLIGHT_OFF",
+	"MIPI_TEAR_ON",
 };
 
 static void generic_exec_sequence(struct intel_dsi *intel_dsi, char *sequence)
@@ -586,6 +648,16 @@ static void generic_disable(struct intel_dsi_device *dsi)
 	generic_exec_sequence(intel_dsi, sequence);
 }
 
+void generic_enable_bklt(struct intel_dsi_device *dsi)
+{
+	struct intel_dsi *intel_dsi = container_of(dsi, struct intel_dsi, dev);
+	struct drm_device *dev = intel_dsi->base.base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	char *sequence = dev_priv->vbt.dsi.sequence[MIPI_SEQ_BACKLIGHT_ON];
+	generic_exec_sequence(intel_dsi, sequence);
+}
+
 static enum drm_connector_status generic_detect(struct intel_dsi_device *dsi)
 {
 	return connector_status_connected;
@@ -618,6 +690,7 @@ struct intel_dsi_dev_ops vbt_generic_dsi_display_ops = {
 	.send_otp_cmds = generic_send_otp_cmds,
 	.enable = generic_enable,
 	.disable = generic_disable,
+	.enable_backlight = generic_enable_bklt,
 	.detect = generic_detect,
 	.get_hw_state = generic_get_hw_state,
 	.get_modes = generic_get_modes,
-- 
2.0.1