[Intel-gfx] [PATCH 08/12] drm: Add lspcon (custom type2 dp->hdmi) support
Sharma, Shashank
shashank.sharma at intel.com
Tue May 3 15:45:48 UTC 2016
Regards
Shashank
On 5/2/2016 7:19 PM, Ville Syrjälä wrote:
> On Mon, Apr 04, 2016 at 05:31:44PM +0530, Shashank Sharma wrote:
>> 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 at intel.com>
>> ---
>> 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);
>
> This sort of stuff shouldn't be needed. All that should be needed is
> passing the right i2c adapter to drm_get_edid() and whatnot.
>
Yeah, agree, we can optimize this.
>> +
>> +/*
>> +* 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);
>
> Aren't these just dupes of the dual mode helper read/write functions?
No, I2C over aux read uses adapter->algo->master_xfer function, which is
different in case of aux channel read/write. dp_dual_mode uses i2c_xfer.
>
>> +
>> 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;
>
> We should reorganize this a bit I think. Probably should end up looking
> somehting like:
>
> bool is_type2_adaptor();
> bool is_lspcon_adaptor();
>
> if (ret == 0) {
> if (is_lspcon_adaptor())
> return TYPE2_LSPCON;
> else if (is_type2_adaptor() && is_hdmi_adaptor)
> return TYPE2_HDMI;
> else if (is_type2_adaptor())
> return TYPE2_DVI;
> }
>
> if (is_hdmi...)
> return TYPE1_HDMI;
> else
> return TYPE1_DVI;
>
>
Yep, this is a good suggestion.
>> 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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