This patch adds support for LSPCON devices in dp++ adaptor
helper layer. LSPCON is DP++ type-2 adaptor with some customized
functionalities, to provide additional features in Intel Gen9 HW.
LSPCON needs I2C-over-aux support to read/write control and
data registers. This patch adds following:
- Functions for I2C over aux read/write
- Function to read EDID using I2c-over-aux
- Function to identify LSPCON among type-2 DP adaptors
Signed-off-by: Shashank Sharma <shashank.sharma@xxxxxxxxx>
---
drivers/gpu/drm/drm_dp_dual_mode_helper.c | 100 ++++++++++++++++++++++++++++++
include/drm/drm_dp_dual_mode_helper.h | 10 +++
2 files changed, 110 insertions(+)
diff --git a/drivers/gpu/drm/drm_dp_dual_mode_helper.c b/drivers/gpu/drm/drm_dp_dual_mode_helper.c
index b72b7bb..ce8e11c 100644
--- a/drivers/gpu/drm/drm_dp_dual_mode_helper.c
+++ b/drivers/gpu/drm/drm_dp_dual_mode_helper.c
@@ -132,6 +132,99 @@ ssize_t drm_dp_dual_mode_write(struct i2c_adapter *adapter,
}
EXPORT_SYMBOL(drm_dp_dual_mode_write);
+int drm_dp_dual_mode_get_edid(void *data,
+ u8 *buf, unsigned int block, size_t len)
+{
+ struct i2c_adapter *adapter = data;
+ unsigned char start = block * EDID_LENGTH;
+ unsigned char segment = block >> 1;
+ unsigned char xfers = segment ? 3 : 2;
+ int ret, retries = 5;
+
+ do {
+ struct i2c_msg msgs[] = {
+ {
+ .addr = DP_DUAL_MODE_DDC_SEGMENT_ADDR,
+ .flags = 0,
+ .len = 1,
+ .buf = &segment,
+ }, {
+ .addr = DDC_ADDR,
+ .flags = 0,
+ .len = 1,
+ .buf = &start,
+ }, {
+ .addr = DDC_ADDR,
+ .flags = I2C_M_RD,
+ .len = len,
+ .buf = buf,
+ }
+ };
+
+ ret = adapter->algo->master_xfer(adapter, &msgs[3 - xfers],
+ xfers);
+
+ if (ret == -ENXIO) {
+ DRM_ERROR("Non-existent adapter %s\n",
+ adapter->name);
+ break;
+ }
+ } while (ret != xfers && --retries);
+
+ return ret == xfers ? 0 : -1;
+}
+EXPORT_SYMBOL(drm_dp_dual_mode_get_edid);
+
+/*
+* drm_dp_dual_mode_ioa_xfer
+* Few dp->hdmi type 2 adaptors allow i2c_over_aux read/write
+* to the control and status registers. These functions help
+* to read/write from those.
+*/
+static int drm_dp_dual_mode_ioa_xfer(struct i2c_adapter *adapter,
+ u8 *buffer, u8 offset, u8 no_of_bytes, u8 rw_flag)
+{
+ int err = 0;
+
+ struct i2c_msg msgs[] = {
+ {
+ .addr = DP_DUAL_MODE_SLAVE_ADDRESS,
+ .flags = 0,
+ .len = 1,
+ .buf = &offset,
+ }, {
+ .addr = DP_DUAL_MODE_SLAVE_ADDRESS,
+ .flags = rw_flag,
+ .len = no_of_bytes,
+ .buf = buffer,
+ }
+ };
+
+ /* I2C over AUX here */
+ err = adapter->algo->master_xfer(adapter, msgs, 2);
+ if (err < 0)
+ DRM_ERROR("LSPCON: Failed I2C over Aux read(addr=0x%x)\n",
+ (unsigned int)offset);
+
+ return err;
+}
+
+int drm_dp_dual_mode_ioa_read(struct i2c_adapter *adapter, u8 *buffer,
+ u8 offset, u8 no_of_bytes)
+{
+ return drm_dp_dual_mode_ioa_xfer(adapter, buffer, offset,
+ no_of_bytes, I2C_M_RD);
+}
+EXPORT_SYMBOL(drm_dp_dual_mode_ioa_read);
+
+int drm_dp_dual_mode_ioa_write(struct i2c_adapter *adapter, u8 *buffer,
+ u8 offset, u8 no_of_bytes)
+{
+ return drm_dp_dual_mode_ioa_xfer(adapter, buffer, offset,
+ no_of_bytes, 0);
+}
+EXPORT_SYMBOL(drm_dp_dual_mode_ioa_write);
+
static bool is_hdmi_adaptor(const char hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN])
{
static const char dp_dual_mode_hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN] =
@@ -141,6 +234,11 @@ static bool is_hdmi_adaptor(const char hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN])
sizeof(dp_dual_mode_hdmi_id)) == 0;
}
+bool is_lspcon_adaptor(const uint8_t adaptor_id)
+{
+ return adaptor_id == 0xa8;
+}
+
/**
* drm_dp_dual_mode_detect - Identyfy the DP dual mode adaptor
* adapter: I2C adapter for the DDC bus
@@ -197,6 +295,8 @@ enum drm_dp_dual_mode_type drm_dp_dual_mode_detect(struct i2c_adapter *adapter)
&adaptor_id, sizeof(adaptor_id));
if (ret || (adaptor_id != (DP_DUAL_MODE_TYPE_TYPE2 |
DP_DUAL_MODE_REV_TYPE2))) {
+ if (is_lspcon_adaptor(adaptor_id))
+ return DRM_DP_DUAL_MODE_TYPE2_LSPCON;
if (is_hdmi_adaptor(hdmi_id))
return DRM_DP_DUAL_MODE_TYPE1_HDMI;
else
diff --git a/include/drm/drm_dp_dual_mode_helper.h b/include/drm/drm_dp_dual_mode_helper.h
index 8f8a8dc..26e3dd8 100644
--- a/include/drm/drm_dp_dual_mode_helper.h
+++ b/include/drm/drm_dp_dual_mode_helper.h
@@ -24,6 +24,7 @@
#define DRM_DP_DUAL_MODE_HELPER_H
#include <linux/types.h>
+#include <drm/drm_edid.h>
/*
* Optional for type 1 DVI adaptors
@@ -55,6 +56,7 @@
#define DP_DUAL_MODE_CEC_ENABLE 0x01
#define DP_DUAL_MODE_I2C_SPEED_CTRL 0x22
#define DP_DUAL_MODE_LAST_RESERVED 0xff
+#define DP_DUAL_MODE_DDC_SEGMENT_ADDR 0x30
struct i2c_adapter;
@@ -69,6 +71,7 @@ enum drm_dp_dual_mode_type {
DRM_DP_DUAL_MODE_TYPE1_HDMI,
DRM_DP_DUAL_MODE_TYPE2_DVI,
DRM_DP_DUAL_MODE_TYPE2_HDMI,
+ DRM_DP_DUAL_MODE_TYPE2_LSPCON,
};
enum drm_dp_dual_mode_type drm_dp_dual_mode_detect(struct i2c_adapter *adapter);
@@ -81,4 +84,11 @@ drm_dp_dual_mode_set_tmds_output(struct i2c_adapter *adapter, bool enable);
const char
*drm_dp_get_dual_mode_type_name(enum drm_dp_dual_mode_type type);
+int drm_dp_dual_mode_ioa_read(struct i2c_adapter *adapter, u8 *buffer,
+ u8 offset, u8 no_of_bytes);
+int drm_dp_dual_mode_ioa_write(struct i2c_adapter *adapter, u8 *buffer,
+ u8 offset, u8 no_of_bytes);
+int drm_dp_dual_mode_get_edid(void *data,
+ u8 *buf, unsigned int block, size_t len);
+
#endif
--
1.9.1
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