[Intel-gfx] [PATCH 1/5] drm: Helper for LSPCON in drm_dp_dual_mode
Ville Syrjälä
ville.syrjala at linux.intel.com
Tue May 31 09:52:53 UTC 2016
On Tue, May 31, 2016 at 02:55:42PM +0530, Shashank Sharma wrote:
> Signed-off-by: Shashank Sharma <shashank.sharma at intel.com>
> ---
> drivers/gpu/drm/drm_dp_dual_mode_helper.c | 85 +++++++++++++++++++++++++++++++
> include/drm/drm_dp_dual_mode_helper.h | 29 +++++++++++
> 2 files changed, 114 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_dp_dual_mode_helper.c b/drivers/gpu/drm/drm_dp_dual_mode_helper.c
> index a7b2a75..11cab25 100644
> --- a/drivers/gpu/drm/drm_dp_dual_mode_helper.c
> +++ b/drivers/gpu/drm/drm_dp_dual_mode_helper.c
> @@ -148,6 +148,12 @@ 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 == 0xa8);
I'd probably make this something like
#define DP_DUAL_MODE_RESERVED_LSPCON 0x08
return adaptor_id == (DP_DUAL_MODE_TYPE_TYPE2 |
DP_DUAL_MODE_RESERVED_LSPCON |
DP_DUAL_MODE_REV_TYPE2);
> +}
> +
> /**
> * drm_dp_dual_mode_detect - Identify the DP dual mode adaptor
> * @adapter: I2C adapter for the DDC bus
> @@ -203,6 +209,8 @@ 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 +372,80 @@ 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_current_mode: Get LSPCON's current mode of operation by
> + * by reading offset (0x80, 0x41)
> + * @i2c_adapter: I2C-over-aux adapter
> + *
> + * Returns:
> + * Enum representing current mode of operation
> + */
> +enum drm_lspcon_mode
> +drm_lspcon_get_current_mode(struct i2c_adapter *adapter)
To match with drm_dp_dual_mode_get_tmds_output() this may want to
return the error status, and return the actual mode via a function
argument.
As for the name drm_dp_dual_mode_get_lspcon_mode() and
drm_dp_dual_mode_set_lspcon_mode() perhaps?
Or drm_lspcon_get_mode()/drm_lspcon_set_mode() perhaps if we want to
keep things shorter?
> +{
> + u8 data;
> + int err = 0;
I used 'ret' in the rest of the code. This is a bit inconsistent.
> +
> + /* Read Status: i2c over aux */
> + err = drm_dp_dual_mode_read(adapter, DP_DUAL_MODE_LSPCON_CURRENT_MODE,
> + (void *)&data, sizeof(data));
Pointless cast.
> + if (err < 0) {
if (ret) is what I've used elsewhere.
> + DRM_ERROR("LSPCON read(0x80, 0x41) failed\n");
I'm not sure we want and ERROR from a helper. I used DRM_DEBUG_KMS for
the other error paths.
> + return DRM_LSPCON_MODE_INVALID;
> + }
> +
> + return data & DP_DUAL_MODE_LSPCON_MODE_MASK ?
> + DRM_LSPCON_MODE_PCON : DRM_LSPCON_MODE_LS;
> +}
> +EXPORT_SYMBOL(drm_lspcon_get_current_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_change_mode(struct i2c_adapter *adapter,
> + enum drm_lspcon_mode reqd_mode)
> +{
> + u8 data;
> + int err;
> + int time_out = 200;
> +
> + if (reqd_mode == DRM_LSPCON_MODE_LS)
> + data = ~DP_DUAL_MODE_LSPCON_MODE_MASK;
Is that really correct?
> + else
> + data = DP_DUAL_MODE_LSPCON_MODE_MASK;
> +
> + /* Change mode */
> + err = drm_dp_dual_mode_write(adapter, DP_DUAL_MODE_LSPCON_MODE_CHANGE,
> + &data, sizeof(data));
> + if (err < 0) {
> + DRM_ERROR("LSPCON mode change failed\n");
> + return err;
> + }
> +
> + /*
> + * 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.
> + */
indent fail
> + while (time_out) {
> + if (reqd_mode != drm_lspcon_get_current_mode(adapter)) {
> + mdelay(10);
mdelay() is bad.
> + time_out -= 10;
> + } else {
> + DRM_DEBUG_KMS("LSPCON mode changed to %s\n",
> + reqd_mode == DRM_LSPCON_MODE_LS ? "LS" : "PCON");
> + return 0;
> + }
> + }
> +
> + DRM_ERROR("LSPCON mode change timed out\n");
> + return -EFAULT;
EFAULT doens't seem like a sensible error value here. ETIMEDOUT I
suppose seems like what we should return.
> +}
> +EXPORT_SYMBOL(drm_lspcon_change_mode);
> diff --git a/include/drm/drm_dp_dual_mode_helper.h b/include/drm/drm_dp_dual_mode_helper.h
> index e8a9dfd..f335df5 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
> @@ -54,6 +55,9 @@
> #define DP_DUAL_MODE_HDMI_PIN_CTRL 0x21
> #define DP_DUAL_MODE_CEC_ENABLE 0x01
> #define DP_DUAL_MODE_I2C_SPEED_CTRL 0x22
Maybe leave an empty line here to separate the standard regs from the
vendor specific ones. Hmm. Actually the vendor register space is
0x30-0x3f, whereas 0x40+ is reserved. But anyway empty line would
seem warranted.
> +#define DP_DUAL_MODE_LSPCON_MODE_CHANGE 0x40
> +#define DP_DUAL_MODE_LSPCON_CURRENT_MODE 0x41
> +#define DP_DUAL_MODE_LSPCON_MODE_MASK 0x1
Please indent the bit defnition by one space to make it stand out from
the reg defines a little.
> struct i2c_adapter;
>
> @@ -63,6 +67,20 @@ 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_invalid: No idea what's going on
> +* @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,
> +};
If we change the _get_mode() thing to return the error status separately
from the mode, we won't need the INVALID value.
> +
> +/**
> * enum drm_dp_dual_mode_type - Type of the DP dual mode adaptor
> * @DRM_DP_DUAL_MODE_NONE: No DP dual mode adaptor
> * @DRM_DP_DUAL_MODE_UNKNOWN: Could be either none or type 1 DVI adaptor
> @@ -70,6 +88,7 @@ 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 +97,7 @@ 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 +109,13 @@ 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_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);
> +enum drm_lspcon_mode drm_lspcon_get_current_mode(struct i2c_adapter *adapter);
> +int drm_lspcon_change_mode(struct i2c_adapter *adapter,
> + enum drm_lspcon_mode reqd_mode);
> #endif
> --
> 1.9.1
--
Ville Syrjälä
Intel OTC
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