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Message-ID: <CAOw6vbJWdrzHwa9cEintihco8=UYC+irPXOomAbjWeruwUW9Nw@mail.gmail.com>
Date: Tue, 12 Jul 2016 08:29:38 -0700
From: Sean Paul <seanpaul@...omium.org>
To: Yakir Yang <ykk@...k-chips.com>
Cc: Mark Yao <yzq@...k-chips.com>, Inki Dae <inki.dae@...sung.com>,
Jingoo Han <jingoohan1@...il.com>,
Heiko Stuebner <heiko@...ech.de>,
Daniel Vetter <daniel.vetter@...ll.ch>,
Stéphane Marchesin <marcheu@...omium.org>,
Tomasz Figa <tfiga@...omium.org>,
Doug Anderson <dianders@...omium.org>,
Thierry Reding <treding@...dia.com>,
Krzysztof Kozlowski <k.kozlowski@...sung.com>,
Javier Martinez Canillas <javier@....samsung.com>,
David Airlie <airlied@...ux.ie>,
Emil Velikov <emil.l.velikov@...il.com>,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
dri-devel <dri-devel@...ts.freedesktop.org>,
linux-samsung-soc <linux-samsung-soc@...r.kernel.org>,
linux-rockchip@...ts.infradead.org
Subject: Re: [PATCH v3 3/4] drm/bridge: analogix_dp: add the PSR function support
On Thu, Jul 7, 2016 at 7:26 PM, Yakir Yang <ykk@...k-chips.com> wrote:
> Sean,
>
> Thanks for your review.
>
>
> On 07/02/2016 03:46 AM, Sean Paul wrote:
>>
>> On Fri, Jul 1, 2016 at 5:19 AM, Yakir Yang <ykk@...k-chips.com> wrote:
>>>
>>> The full name of PSR is Panel Self Refresh, panel device could refresh
>>> itself with the hardware framebuffer in panel, this would make lots of
>>> sense to save the power consumption.
>>>
>>> This patch have exported two symbols for platform driver to implement
>>> the PSR function in hardware side:
>>> - analogix_dp_active_psr()
>>> - analogix_dp_inactive_psr()
>>>
>>> Signed-off-by: Yakir Yang <ykk@...k-chips.com>
>>> ---
>>> Changes in v3:
>>> - split analogix_dp_enable_psr(), make it more clearly
>>> analogix_dp_detect_sink_psr()
>>> analogix_dp_enable_sink_psr()
>>> - remove some nosie register setting comments
>>>
>>> Changes in v2:
>>> - introduce in v2, splite the common Analogix DP changes out
>>>
>>> drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 64
>>> ++++++++++++++++++++++
>>> drivers/gpu/drm/bridge/analogix/analogix_dp_core.h | 4 ++
>>> drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c | 54
>>> ++++++++++++++++++
>>> drivers/gpu/drm/bridge/analogix/analogix_dp_reg.h | 28 ++++++++++
>>> include/drm/bridge/analogix_dp.h | 3 +
>>> 5 files changed, 153 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>>> b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>>> index 32715da..b557097 100644
>>> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>>> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>>> @@ -97,6 +97,66 @@ static int analogix_dp_detect_hpd(struct
>>> analogix_dp_device *dp)
>>> return 0;
>>> }
>>>
>>> +int analogix_dp_active_psr(struct device *dev)
>>> +{
>>> + struct analogix_dp_device *dp = dev_get_drvdata(dev);
>>> +
>>> + if (!dp->psr_support)
>>> + return -EINVAL;
>>> +
>>> + analogix_dp_send_psr_spd(dp, EDP_VSC_PSR_STATE_ACTIVE |
>>> + EDP_VSC_PSR_CRC_VALUES_VALID);
>>> + return 0;
>>> +}
>>> +EXPORT_SYMBOL_GPL(analogix_dp_active_psr);
>>> +
>>> +int analogix_dp_inactive_psr(struct device *dev)
>>> +{
>>> + struct analogix_dp_device *dp = dev_get_drvdata(dev);
>>> +
>>> + if (!dp->psr_support)
>>> + return -EINVAL;
>>> +
>>> + analogix_dp_send_psr_spd(dp, 0);
>>> + return 0;
>>> +}
>>> +EXPORT_SYMBOL_GPL(analogix_dp_inactive_psr);
>>> +
>>> +static bool analogix_dp_detect_sink_psr(struct analogix_dp_device *dp)
>>> +{
>>> + unsigned char psr_version;
>>> +
>>> + analogix_dp_read_byte_from_dpcd(dp, DP_PSR_SUPPORT,
>>> &psr_version);
>>> + dev_info(dp->dev, "Panel PSR version : %x\n", psr_version);
>>> +
>>
>> This info message is likely to be spammy since it's printed everytime
>> the panel toggle on. Perhaps downgrade to debug level.
>
>
> Okay, done.
>
>>> + return (psr_version & DP_PSR_IS_SUPPORTED) ? true : false;
>>> +}
>>> +
>>> +static int analogix_dp_enable_sink_psr(struct analogix_dp_device *dp)
>>
>> Return type is int, but the function never fails and you don't check
>> the return value when calling it. Seems like this should be void.
>
>
> Done.
>
>>> +{
>>> + unsigned char psr_en;
>>> +
>>> + /* Disable psr function */
>>> + analogix_dp_read_byte_from_dpcd(dp, DP_PSR_EN_CFG, &psr_en);
>>> + psr_en &= ~DP_PSR_ENABLE;
>>> + analogix_dp_write_byte_to_dpcd(dp, DP_PSR_EN_CFG, psr_en);
>>> +
>>> + /* Main-Link transmitter remains active during PSR active states
>>> */
>>> + analogix_dp_read_byte_from_dpcd(dp, DP_PSR_EN_CFG, &psr_en);
>>> + psr_en = DP_PSR_MAIN_LINK_ACTIVE | DP_PSR_CRC_VERIFICATION;
>>
>> Why read psr_en if you're just going to overwrite it? Perhaps you meant |=
>> here.
>>
>
> Yes, it's my mistaken, no need to read the DP_PSR_EN_CFG, just configure it
> directly is enough.
>
>>> + analogix_dp_write_byte_to_dpcd(dp, DP_PSR_EN_CFG, psr_en);
>>> +
>>> + /* Enable psr function */
>>> + analogix_dp_read_byte_from_dpcd(dp, DP_PSR_EN_CFG, &psr_en);
>>> + psr_en = DP_PSR_ENABLE | DP_PSR_MAIN_LINK_ACTIVE |
>>> + DP_PSR_CRC_VERIFICATION;
>>
>> Again, no need to read if you're just overwriting.
>
>
> Yes, ditto
>
>
>>> + analogix_dp_write_byte_to_dpcd(dp, DP_PSR_EN_CFG, psr_en);
>>> +
>>> + analogix_dp_enable_psr_crc(dp);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> static unsigned char analogix_dp_calc_edid_check_sum(unsigned char
>>> *edid_data)
>>> {
>>> int i;
>>> @@ -921,6 +981,10 @@ static void analogix_dp_commit(struct
>>> analogix_dp_device *dp)
>>>
>>> /* Enable video */
>>> analogix_dp_start_video(dp);
>>> +
>>> + dp->psr_support = analogix_dp_detect_sink_psr(dp);
>>> + if (dp->psr_support)
>>> + analogix_dp_enable_sink_psr(dp);
>>> }
>>>
>>> int analogix_dp_get_modes(struct drm_connector *connector)
>>> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
>>> b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
>>> index b456380..6ca5dde 100644
>>> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
>>> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
>>> @@ -177,6 +177,7 @@ struct analogix_dp_device {
>>> int hpd_gpio;
>>> bool force_hpd;
>>> unsigned char edid[EDID_BLOCK_LENGTH * 2];
>>> + bool psr_support;
>>>
>>> struct analogix_dp_plat_data *plat_data;
>>> };
>>> @@ -278,4 +279,7 @@ int analogix_dp_is_video_stream_on(struct
>>> analogix_dp_device *dp);
>>> void analogix_dp_config_video_slave_mode(struct analogix_dp_device
>>> *dp);
>>> void analogix_dp_enable_scrambling(struct analogix_dp_device *dp);
>>> void analogix_dp_disable_scrambling(struct analogix_dp_device *dp);
>>> +void analogix_dp_enable_psr_crc(struct analogix_dp_device *dp);
>>> +void analogix_dp_send_psr_spd(struct analogix_dp_device *dp, int db1);
>>> +
>>> #endif /* _ANALOGIX_DP_CORE_H */
>>> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
>>> b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
>>> index 48030f0..e8372c7 100644
>>> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
>>> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
>>> @@ -1322,3 +1322,57 @@ void analogix_dp_disable_scrambling(struct
>>> analogix_dp_device *dp)
>>> reg |= SCRAMBLING_DISABLE;
>>> writel(reg, dp->reg_base + ANALOGIX_DP_TRAINING_PTN_SET);
>>> }
>>> +
>>> +void analogix_dp_enable_psr_crc(struct analogix_dp_device *dp)
>>> +{
>>> + writel(PSR_VID_CRC_FLUSH | PSR_VID_CRC_ENABLE,
>>> + dp->reg_base + ANALOGIX_DP_CRC_CON);
>>> +
>>> + usleep_range(10, 20);
>>
>> Is this sleep arbitrary, or documented somewhere? Could you add a
>> comment explaining how this was arrived at?
>>
>
> Yes, this sleep is arbitrary, there is no document about the
>
Ok, so I assume we actually need the delay for things to work? If not,
delete the delay. If we need it, please add a comment saying the wait
is required and the value was chosen via trial and error.
>
>>> +
>>> + writel(PSR_VID_CRC_ENABLE, dp->reg_base + ANALOGIX_DP_CRC_CON);
>>> +}
>>> +
>>> +void analogix_dp_send_psr_spd(struct analogix_dp_device *dp, int db1)
>>> +{
>>> + unsigned int val;
>>> +
>>> + /* don't send info frame */
>>> + val = readl(dp->reg_base + ANALOGIX_DP_PKT_SEND_CTL);
>>> + val &= ~IF_EN;
>>> + writel(val, dp->reg_base + ANALOGIX_DP_PKT_SEND_CTL);
>>> +
>>> + /* configure single frame update mode */
>>> + writel(0x3, dp->reg_base + ANALOGIX_DP_PSR_FRAME_UPDATE_CTRL);
>>> +
>>> + /* configure VSC HB0 ~ HB3 */
>>> + writel(0x00, dp->reg_base + ANALOGIX_DP_SPD_HB0);
>>> + writel(0x07, dp->reg_base + ANALOGIX_DP_SPD_HB1);
>>> + writel(0x02, dp->reg_base + ANALOGIX_DP_SPD_HB2);
>>> + writel(0x08, dp->reg_base + ANALOGIX_DP_SPD_HB3);
>>> +
>>> + /* configure VSC HB0 ~ HB3 */
>>> + writel(0x00, dp->reg_base + ANALOGIX_DP_SPD_PB0);
>>> + writel(0x16, dp->reg_base + ANALOGIX_DP_SPD_PB1);
>>> + writel(0xCE, dp->reg_base + ANALOGIX_DP_SPD_PB2);
>>> + writel(0x5D, dp->reg_base + ANALOGIX_DP_SPD_PB3);
>>> +
>>> + /* configure DB0 / DB1 values */
>>> + writel(0x00, dp->reg_base + ANALOGIX_DP_VSC_SHADOW_DB0);
>>
>> Lots of hardcoded values here. I think this could be cleaned up.
>
>
> For "HB0~HB3", "PB0~PB3" and "DB1", I don't understand very well. Those
> seems to be a kind of head number, I got those magic values from our IC
> side. So I think those should be okay to keep the hardcode values here :-D
>
Hmm. Well, I'd probably pull them out into some HBX_MAGIC_VALUE
define, but I suppose it's fine to keep them as-is. Please at least
add a comment above explaining that they're magic values provided by
your IC team.
> But for the "0x3" in "ANALOGIX_DP_PSR_FRAME_UPDATE_CTRL", I would fix it
> with suitable macro.
>
>
>>> + writel(db1, dp->reg_base + ANALOGIX_DP_VSC_SHADOW_DB1);
>>> +
>>> + /* set reuse spd inforframe */
>>> + val = readl(dp->reg_base + ANALOGIX_DP_VIDEO_CTL_3);
>>> + val |= REUSE_SPD_EN;
>>> + writel(val, dp->reg_base + ANALOGIX_DP_VIDEO_CTL_3);
>>> +
>>> + /* mark info frame update */
>>> + val = readl(dp->reg_base + ANALOGIX_DP_PKT_SEND_CTL);
>>> + val = (val | IF_UP) & ~IF_EN;
>>> + writel(val, dp->reg_base + ANALOGIX_DP_PKT_SEND_CTL);
>>> +
>>> + /* send info frame */
>>> + val = readl(dp->reg_base + ANALOGIX_DP_PKT_SEND_CTL);
>>> + val |= IF_EN;
>>> + writel(val, dp->reg_base + ANALOGIX_DP_PKT_SEND_CTL);
>>> +}
>>> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.h
>>> b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.h
>>> index cdcc6c5..a2698e4 100644
>>> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.h
>>> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.h
>>> @@ -22,6 +22,8 @@
>>> #define ANALOGIX_DP_VIDEO_CTL_8 0x3C
>>> #define ANALOGIX_DP_VIDEO_CTL_10 0x44
>>>
>>> +#define ANALOGIX_DP_SPDIF_AUDIO_CTL_0 0xD8
>>> +
>>> #define ANALOGIX_DP_PLL_REG_1 0xfc
>>> #define ANALOGIX_DP_PLL_REG_2 0x9e4
>>> #define ANALOGIX_DP_PLL_REG_3 0x9e8
>>> @@ -30,6 +32,21 @@
>>>
>>> #define ANALOGIX_DP_PD 0x12c
>>>
>>> +#define ANALOGIX_DP_IF_TYPE 0x244
>>> +#define ANALOGIX_DP_IF_PKT_DB1 0x254
>>> +#define ANALOGIX_DP_IF_PKT_DB2 0x258
>>> +#define ANALOGIX_DP_SPD_HB0 0x2F8
>>> +#define ANALOGIX_DP_SPD_HB1 0x2FC
>>> +#define ANALOGIX_DP_SPD_HB2 0x300
>>> +#define ANALOGIX_DP_SPD_HB3 0x304
>>> +#define ANALOGIX_DP_SPD_PB0 0x308
>>> +#define ANALOGIX_DP_SPD_PB1 0x30C
>>> +#define ANALOGIX_DP_SPD_PB2 0x310
>>> +#define ANALOGIX_DP_SPD_PB3 0x314
>>> +#define ANALOGIX_DP_PSR_FRAME_UPDATE_CTRL 0x318
>>> +#define ANALOGIX_DP_VSC_SHADOW_DB0 0x31C
>>> +#define ANALOGIX_DP_VSC_SHADOW_DB1 0x320
>>> +
>>> #define ANALOGIX_DP_LANE_MAP 0x35C
>>>
>>> #define ANALOGIX_DP_ANALOG_CTL_1 0x370
>>> @@ -103,6 +120,8 @@
>>>
>>> #define ANALOGIX_DP_SOC_GENERAL_CTL 0x800
>>>
>>> +#define ANALOGIX_DP_CRC_CON 0x890
>>> +
>>> /* ANALOGIX_DP_TX_SW_RESET */
>>> #define RESET_DP_TX (0x1 << 0)
>>>
>>> @@ -151,6 +170,7 @@
>>> #define VID_CHK_UPDATE_TYPE_SHIFT (4)
>>> #define VID_CHK_UPDATE_TYPE_1 (0x1 << 4)
>>> #define VID_CHK_UPDATE_TYPE_0 (0x0 << 4)
>>> +#define REUSE_SPD_EN (0x1 << 3)
>>>
>>> /* ANALOGIX_DP_VIDEO_CTL_8 */
>>> #define VID_HRES_TH(x) (((x) & 0xf) << 4)
>>> @@ -376,4 +396,12 @@
>>> #define VIDEO_MODE_SLAVE_MODE (0x1 << 0)
>>> #define VIDEO_MODE_MASTER_MODE (0x0 << 0)
>>>
>>> +/* ANALOGIX_DP_PKT_SEND_CTL */
>>> +#define IF_UP (0x1 << 4)
>>> +#define IF_EN (0x1 << 0)
>>> +
>>> +/* ANALOGIX_DP_CRC_CON */
>>> +#define PSR_VID_CRC_FLUSH (0x1 << 2)
>>> +#define PSR_VID_CRC_ENABLE (0x1 << 0)
>>> +
>>> #endif /* _ANALOGIX_DP_REG_H */
>>> diff --git a/include/drm/bridge/analogix_dp.h
>>> b/include/drm/bridge/analogix_dp.h
>>> index 261b86d..183a336 100644
>>> --- a/include/drm/bridge/analogix_dp.h
>>> +++ b/include/drm/bridge/analogix_dp.h
>>> @@ -38,6 +38,9 @@ struct analogix_dp_plat_data {
>>> struct drm_connector *);
>>> };
>>>
>>> +int analogix_dp_active_psr(struct device *dev);
>>> +int analogix_dp_inactive_psr(struct device *dev);
>>
>> Why active/inactive instead of enable/disable, which is used everywhere
>> else?
>
>
> Done
>
> Thanks,
> - Yakir
>
>
>>> +
>>> int analogix_dp_resume(struct device *dev);
>>> int analogix_dp_suspend(struct device *dev);
>>>
>>> --
>>> 1.9.1
>>>
>>>
>>
>>
>
>
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