From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752049AbeENS7Q (ORCPT ); Mon, 14 May 2018 14:59:16 -0400 Received: from mx08-00178001.pphosted.com ([91.207.212.93]:37387 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751449AbeENS7O (ORCPT ); Mon, 14 May 2018 14:59:14 -0400 From: Philippe CORNU To: Andrzej Hajda , Archit Taneja , Laurent Pinchart , David Airlie , "Rob Herring" , Mark Rutland , "dri-devel@lists.freedesktop.org" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" CC: Yannick FERTRE , Benjamin Gaignard , Alexandre TORGUE Subject: Re: [PATCH v2 2/2] drm/bridge: sii902x: add optional power supplies Thread-Topic: [PATCH v2 2/2] drm/bridge: sii902x: add optional power supplies Thread-Index: AQHT3GqO5f7596VGtE+CsIvlD/pnwKQu9GaAgAAPUwCAAI0XgA== Date: Mon, 14 May 2018 18:58:48 +0000 Message-ID: <8ed2cfcd-df26-fa9c-c45d-7bf4020f0faa@st.com> References: <20180425075314.19137-1-philippe.cornu@st.com> <20180425075314.19137-3-philippe.cornu@st.com> <69a9da79-63df-6d0a-52e3-729ec8937484@samsung.com> In-Reply-To: <69a9da79-63df-6d0a-52e3-729ec8937484@samsung.com> Accept-Language: fr-FR, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: user-agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.75.127.47] Content-Type: text/plain; charset="utf-8" Content-ID: MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-05-14_04:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id w4EIxLmu015496 Hi Andrzej, On 05/14/2018 12:33 PM, Andrzej Hajda wrote: > On 14.05.2018 11:38, Philippe CORNU wrote: >> Hi Laurent, Archit, Andrzej & Yannick, >> >> Do you have any comments on this v2 driver part? >> (more details regarding v1/v2 differences in the cover letter >> https://www.spinics.net/lists/dri-devel/msg174137.html) >> >> Thank you, >> Philippe :-) >> >> >> On 04/25/2018 09:53 AM, Philippe Cornu wrote: >>> Add the optional power supplies using the description found in >>> "SiI9022A/SiI9024A HDMI Transmitter Data Sheet (August 2016)". >>> >>> The sii902x input IOs are not "io safe" so it is important to >>> enable/disable voltage regulators during probe/remove phases to >>> avoid damages. > > What exactly does it mean? Ie I understand that the chip has some > limitations, but why enabling/disabling regulators in probe/remove > should solve it? thank you for your comment. And sorry for the "bad" explanation in the 2nd paragraph about the fact that inputs are not "io safe". I added this 2nd paragraph in v2 following a good comment from Laurent on adding the management of the regulators outside the probe/remove for a better power consumption management (enable/disable regulators only when the ic is used for displaying something for instance...). But after a deeper analysis, I realized that the only way to improve the power consumption is to implement & test the sii902x various sleep modes, that is out-of-scope of this small patch and also out-of-scope of my test board I use on which the sii902x bridge ic power consumption is very low compare to the rest of the system... I will remove this "explanation" in v3 as it creates confusion. Many thanks, Philippe :-) > > Regards > Andrzej > >>> >>> Signed-off-by: Philippe Cornu >>> --- >>> drivers/gpu/drm/bridge/sii902x.c | 38 ++++++++++++++++++++++++++++++++++---- >>> 1 file changed, 34 insertions(+), 4 deletions(-) >>> >>> diff --git a/drivers/gpu/drm/bridge/sii902x.c b/drivers/gpu/drm/bridge/sii902x.c >>> index 60373d7eb220..c367d7b91ade 100644 >>> --- a/drivers/gpu/drm/bridge/sii902x.c >>> +++ b/drivers/gpu/drm/bridge/sii902x.c >>> @@ -24,6 +24,7 @@ >>> #include >>> #include >>> #include >>> +#include >>> >>> #include >>> #include >>> @@ -86,6 +87,7 @@ struct sii902x { >>> struct drm_bridge bridge; >>> struct drm_connector connector; >>> struct gpio_desc *reset_gpio; >>> + struct regulator_bulk_data supplies[2]; >>> }; >>> >>> static inline struct sii902x *bridge_to_sii902x(struct drm_bridge *bridge) >>> @@ -392,23 +394,42 @@ static int sii902x_probe(struct i2c_client *client, >>> return PTR_ERR(sii902x->reset_gpio); >>> } >>> >>> + sii902x->supplies[0].supply = "iovcc"; >>> + sii902x->supplies[1].supply = "vcc12"; >>> + ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(sii902x->supplies), >>> + sii902x->supplies); >>> + if (ret) { >>> + dev_err(dev, "Failed to get power supplies: %d\n", ret); >>> + return ret; >>> + } >>> + >>> + ret = regulator_bulk_enable(ARRAY_SIZE(sii902x->supplies), >>> + sii902x->supplies); >>> + if (ret) { >>> + dev_err(dev, "Failed to enable power supplies: %d\n", ret); >>> + return ret; >>> + } >>> + >>> + usleep_range(10000, 20000); >>> + >>> sii902x_reset(sii902x); >>> >>> ret = regmap_write(sii902x->regmap, SII902X_REG_TPI_RQB, 0x0); >>> if (ret) >>> - return ret; >>> + goto err_disable_regulator; >>> >>> ret = regmap_bulk_read(sii902x->regmap, SII902X_REG_CHIPID(0), >>> &chipid, 4); >>> if (ret) { >>> dev_err(dev, "regmap_read failed %d\n", ret); >>> - return ret; >>> + goto err_disable_regulator; >>> } >>> >>> if (chipid[0] != 0xb0) { >>> dev_err(dev, "Invalid chipid: %02x (expecting 0xb0)\n", >>> chipid[0]); >>> - return -EINVAL; >>> + ret = -EINVAL; >>> + goto err_disable_regulator; >>> } >>> >>> /* Clear all pending interrupts */ >>> @@ -424,7 +445,7 @@ static int sii902x_probe(struct i2c_client *client, >>> IRQF_ONESHOT, dev_name(dev), >>> sii902x); >>> if (ret) >>> - return ret; >>> + goto err_disable_regulator; >>> } >>> >>> sii902x->bridge.funcs = &sii902x_bridge_funcs; >>> @@ -434,6 +455,12 @@ static int sii902x_probe(struct i2c_client *client, >>> i2c_set_clientdata(client, sii902x); >>> >>> return 0; >>> + >>> +err_disable_regulator: >>> + regulator_bulk_disable(ARRAY_SIZE(sii902x->supplies), >>> + sii902x->supplies); >>> + >>> + return ret; >>> } >>> >>> static int sii902x_remove(struct i2c_client *client) >>> @@ -443,6 +470,9 @@ static int sii902x_remove(struct i2c_client *client) >>> >>> drm_bridge_remove(&sii902x->bridge); >>> >>> + regulator_bulk_disable(ARRAY_SIZE(sii902x->supplies), >>> + sii902x->supplies); >>> + >>> return 0; >>> } >>> > >