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drm: Helper for lspcon in drm_dp_dual_mode 

This patch adds lspcon support in dp_dual_mode helper.
lspcon is essentially a dp->hdmi dongle with dual personality.

LS mode: It works as a passive dongle, by level shifting DP++
signals to HDMI signals, in LS mode.
PCON mode: It works as a protocol converter active dongle
in pcon mode, by converting DP++ outputs to HDMI 2.0 outputs.

This patch adds support for lspcon detection and mode set
switch operations, as a dp dual mode dongle.

v2: Addressed review comments from Ville
- add adaptor id for lspcon devices (0x08), use it to identify lspcon
- change function names
  old: drm_lspcon_get_current_mode/drm_lspcon_change_mode
  new: drm_lspcon_get_mode/drm_lspcon_set_mode
- change drm_lspcon_get_mode type to int, to match
  drm_dp_dual_mode_get_tmds_output
- change 'err' to 'ret' to match the rest of the functions
- remove pointless typecasting during call to dual_mode_read
- fix the but while setting value of data, while writing lspcon mode
- fix indentation
- change mdelay(10) -> msleep(10)
- return ETIMEDOUT instead of EFAULT, when lspcon mode change times out
- Add an empty line to separate std regs macros and lspcon regs macros
  Indent bit definition

v3: Addressed review comments from Rodrigo
- change macro name from DP_DUAL_MODE_TYPE_LSPCON to
  DP_DUAL_MODE_TYPE_HAS_DPCD for better readability
- change macro name from DP_DUAL_MODE_LSPCON_MODE_PCON to
  DP_DUAL_MODE_LSPCON_MODE_PCON for better readability
- add comment for MCA specific offsets like 0x40 and 0x41
- remove DP_DUAL_MODE_REV_TYPE2 check while checking lspcon adapter id

v4: Addressed review comments from Ville
- Fixed indentation at few places
- s/current_mode/mode
- s/reqd_mode/mode
- remove unnecessary void* cast
- remove drm_edid.h from includes
- Add a comment for _HAS_DPCD
- Fix enum description, for lspcon_mode.

v5: Rebase
v6: Rebase

Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Dave Airlie <airlied@gmail.com>
Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1476720277-16298-1-git-send-email-shashank.sharma@intel.com
This commit is contained in:
Shashank Sharma 2016-10-17 21:34:37 +05:30 committed by Jani Nikula
parent 1140f9ed05
commit 056996b956
2 changed files with 129 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

103
drivers/gpu/drm/drm_dp_dual_mode_helper.c
View File

@ -148,6 +148,14 @@ static bool is_type2_adaptor(uint8_t adaptor_id)
DP_DUAL_MODE_REV_TYPE2);
}
bool is_lspcon_adaptor(const char hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN],
const uint8_t adaptor_id)
{
return is_hdmi_adaptor(hdmi_id) &&
(adaptor_id == (DP_DUAL_MODE_TYPE_TYPE2 |
DP_DUAL_MODE_TYPE_HAS_DPCD));
}
/**
* drm_dp_dual_mode_detect - Identify the DP dual mode adaptor
* @adapter: I2C adapter for the DDC bus
@ -203,6 +211,8 @@ enum drm_dp_dual_mode_type drm_dp_dual_mode_detect(struct i2c_adapter *adapter)
ret = drm_dp_dual_mode_read(adapter, DP_DUAL_MODE_ADAPTOR_ID,
&adaptor_id, sizeof(adaptor_id));
if (ret == 0) {
if (is_lspcon_adaptor(hdmi_id, adaptor_id))
return DRM_DP_DUAL_MODE_LSPCON;
if (is_type2_adaptor(adaptor_id)) {
if (is_hdmi_adaptor(hdmi_id))
return DRM_DP_DUAL_MODE_TYPE2_HDMI;
@ -364,3 +374,96 @@ const char *drm_dp_get_dual_mode_type_name(enum drm_dp_dual_mode_type type)
}
}
EXPORT_SYMBOL(drm_dp_get_dual_mode_type_name);
/**
* drm_lspcon_get_mode: Get LSPCON's current mode of operation by
* by reading offset (0x80, 0x41)
* @i2c_adapter: I2C-over-aux adapter
* @current_mode: out vaiable, current lspcon mode of operation
*
* Returns:
* 0 on success, sets the current_mode value to appropriate mode
* -error on failure
*/
int drm_lspcon_get_mode(struct i2c_adapter *adapter,
enum drm_lspcon_mode *mode)
{
u8 data;
int ret = 0;
if (!mode) {
DRM_ERROR("NULL input\n");
return -EINVAL;
}
/* Read Status: i2c over aux */
ret = drm_dp_dual_mode_read(adapter, DP_DUAL_MODE_LSPCON_CURRENT_MODE,
&data, sizeof(data));
if (ret < 0) {
DRM_ERROR("LSPCON read(0x80, 0x41) failed\n");
return -EFAULT;
}
if (data & DP_DUAL_MODE_LSPCON_MODE_PCON)
*mode = DRM_LSPCON_MODE_PCON;
else
*mode = DRM_LSPCON_MODE_LS;
return 0;
}
EXPORT_SYMBOL(drm_lspcon_get_mode);
/**
* drm_lspcon_change_mode: Change LSPCON's mode of operation by
* by writing offset (0x80, 0x40)
* @i2c_adapter: I2C-over-aux adapter
* @reqd_mode: required mode of operation
*
* Returns:
* 0 on success, -error on failure/timeout
*/
int drm_lspcon_set_mode(struct i2c_adapter *adapter,
enum drm_lspcon_mode mode)
{
u8 data = 0;
int ret;
int time_out = 200;
enum drm_lspcon_mode current_mode;
if (mode == DRM_LSPCON_MODE_PCON)
data = DP_DUAL_MODE_LSPCON_MODE_PCON;
/* Change mode */
ret = drm_dp_dual_mode_write(adapter, DP_DUAL_MODE_LSPCON_MODE_CHANGE,
&data, sizeof(data));
if (ret < 0) {
DRM_ERROR("LSPCON mode change failed\n");
return ret;
}
/*
* Confirm mode change by reading the status bit.
* Sometimes, it takes a while to change the mode,
* so wait and retry until time out or done.
*/
do {
ret = drm_lspcon_get_mode(adapter, &current_mode);
if (ret) {
DRM_ERROR("can't confirm LSPCON mode change\n");
return ret;
} else {
if (current_mode != mode) {
msleep(10);
time_out -= 10;
} else {
DRM_DEBUG_KMS("LSPCON mode changed to %s\n",
mode == DRM_LSPCON_MODE_LS ?
"LS" : "PCON");
return 0;
}
}
} while (time_out);
DRM_ERROR("LSPCON mode change timed out\n");
return -ETIMEDOUT;
}
EXPORT_SYMBOL(drm_lspcon_set_mode);

26
include/drm/drm_dp_dual_mode_helper.h
View File

@ -40,6 +40,8 @@
#define DP_DUAL_MODE_REV_TYPE2 0x00
#define DP_DUAL_MODE_TYPE_MASK 0xf0
#define DP_DUAL_MODE_TYPE_TYPE2 0xa0
/* This field is marked reserved in dual mode spec, used in LSPCON */
#define DP_DUAL_MODE_TYPE_HAS_DPCD 0x08
#define DP_DUAL_MODE_IEEE_OUI 0x11 /* 11-13*/
#define DP_DUAL_IEEE_OUI_LEN 3
#define DP_DUAL_DEVICE_ID 0x14 /* 14-19 */
@ -55,6 +57,11 @@
#define DP_DUAL_MODE_CEC_ENABLE 0x01
#define DP_DUAL_MODE_I2C_SPEED_CTRL 0x22
/* LSPCON specific registers, defined by MCA */
#define DP_DUAL_MODE_LSPCON_MODE_CHANGE 0x40
#define DP_DUAL_MODE_LSPCON_CURRENT_MODE 0x41
#define DP_DUAL_MODE_LSPCON_MODE_PCON 0x1
struct i2c_adapter;
ssize_t drm_dp_dual_mode_read(struct i2c_adapter *adapter,
@ -62,6 +69,19 @@ ssize_t drm_dp_dual_mode_read(struct i2c_adapter *adapter,
ssize_t drm_dp_dual_mode_write(struct i2c_adapter *adapter,
u8 offset, const void *buffer, size_t size);
/**
* enum drm_lspcon_mode
* @lspcon_mode_ls: Level shifter mode of LSPCON
* which drives DP++ to HDMI 1.4 conversion.
* @lspcon_mode_pcon: Protocol converter mode of LSPCON
* which drives DP++ to HDMI 2.0 active conversion.
*/
enum drm_lspcon_mode {
DRM_LSPCON_MODE_INVALID,
DRM_LSPCON_MODE_LS,
DRM_LSPCON_MODE_PCON,
};
/**
* enum drm_dp_dual_mode_type - Type of the DP dual mode adaptor
* @DRM_DP_DUAL_MODE_NONE: No DP dual mode adaptor
@ -70,6 +90,7 @@ ssize_t drm_dp_dual_mode_write(struct i2c_adapter *adapter,
* @DRM_DP_DUAL_MODE_TYPE1_HDMI: Type 1 HDMI adaptor
* @DRM_DP_DUAL_MODE_TYPE2_DVI: Type 2 DVI adaptor
* @DRM_DP_DUAL_MODE_TYPE2_HDMI: Type 2 HDMI adaptor
* @DRM_DP_DUAL_MODE_TYPE2_LSPCON: Level shifter /protocol converter
*/
enum drm_dp_dual_mode_type {
DRM_DP_DUAL_MODE_NONE,
@ -78,6 +99,7 @@ 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_LSPCON,
};
enum drm_dp_dual_mode_type drm_dp_dual_mode_detect(struct i2c_adapter *adapter);
@ -89,4 +111,8 @@ int drm_dp_dual_mode_set_tmds_output(enum drm_dp_dual_mode_type type,
struct i2c_adapter *adapter, bool enable);
const char *drm_dp_get_dual_mode_type_name(enum drm_dp_dual_mode_type type);
int drm_lspcon_get_mode(struct i2c_adapter *adapter,
enum drm_lspcon_mode *current_mode);
int drm_lspcon_set_mode(struct i2c_adapter *adapter,
enum drm_lspcon_mode reqd_mode);
#endif