From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754205AbaKXSSz (ORCPT ); Mon, 24 Nov 2014 13:18:55 -0500 Received: from smtp10.online.nl ([194.134.42.55]:59274 "EHLO smtp10.online.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753943AbaKXSSx (ORCPT ); Mon, 24 Nov 2014 13:18:53 -0500 X-Greylist: delayed 343 seconds by postgrey-1.27 at vger.kernel.org; Mon, 24 Nov 2014 13:18:52 EST Message-ID: <54737532.1050808@milosoftware.com> Date: Mon, 24 Nov 2014 19:13:06 +0100 From: Mike Looijmans User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Grygorii Strashko , =?windows-1252?Q?Uwe_?= =?windows-1252?Q?Kleine-K=F6nig?= CC: Wolfram Sang , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, Sekhar Nori , Kevin Hilman , Santosh Shilimkar , Murali Karicheri , Ben Gardiner , Mike Looijmans Subject: Re: [5/5] i2c: davinci: use ICPFUNC to toggle I2C as gpio for bus recovery References: <1416477788-5544-6-git-send-email-grygorii.strashko@ti.com> <20141123170400.GC4431@pengutronix.de> <54732F8E.4080105@ti.com> In-Reply-To: <54732F8E.4080105@ti.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit X-Online-Scanned: by Cloudmark authority (on smtp10.online.nl) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 24-11-2014 14:15, Grygorii Strashko wrote: > Hi Uwe, > On 11/23/2014 07:04 PM, Uwe Kleine-König wrote: >> On Thu, Nov 20, 2014 at 12:03:08PM +0200, Grygorii Strashko wrote: >>> @@ -664,6 +759,7 @@ static int davinci_i2c_probe(struct platform_device *pdev) >>> if (!of_property_read_u32(pdev->dev.of_node, "clock-frequency", >>> &prop)) >>> dev->pdata->bus_freq = prop / 1000; >>> + dev->pdata->has_pfunc = true; >> I don't understand this. Why does this ICPFUNC recovery work if the bus >> is probed by oftree, but doesn't if not? > I've mentioned this in commit message: > Allow platforms to indicate the presence of the ICPFUNC registers with a has_pfunc > platform data flag and enable this mode for platforms which supports DT (da850 and > Keystone 2 are two SoCs which support DT now and they also support ICPFUNC registers). > > I'll add proper comment here. Just thinking: What happens if you try to use the ICPFUNC registers on platforms that don't support it? If the answer is "nothing bad", then you might as well assume that if the platform doesn't specify its own GPIOs, you can always try using the ICPFUNC registers to shake the I2C bus. Better to try and fail than to never try at all... > >>> } else if (!dev->pdata) { >>> dev->pdata = &davinci_i2c_platform_data_default; >>> } >>> @@ -705,7 +801,9 @@ static int davinci_i2c_probe(struct platform_device *pdev) >>> adap->timeout = DAVINCI_I2C_TIMEOUT; >>> adap->dev.of_node = pdev->dev.of_node; >>> >>> - if (dev->pdata->scl_pin) { >>> + if (dev->pdata->has_pfunc) >>> + adap->bus_recovery_info = &davinci_i2c_scl_recovery_info; >>> + else if (dev->pdata->scl_pin) { >>> adap->bus_recovery_info = &davinci_i2c_gpio_recovery_info; >>> adap->bus_recovery_info->scl_gpio = dev->pdata->scl_pin; >>> adap->bus_recovery_info->sda_gpio = dev->pdata->sda_pin; >>> diff --git a/include/linux/platform_data/i2c-davinci.h b/include/linux/platform_data/i2c-davinci.h >>> index 2312d19..89fd347 100644 >>> --- a/include/linux/platform_data/i2c-davinci.h >>> +++ b/include/linux/platform_data/i2c-davinci.h >>> @@ -18,6 +18,7 @@ struct davinci_i2c_platform_data { >>> unsigned int bus_delay; /* post-transaction delay (usec) */ >>> unsigned int sda_pin; /* GPIO pin ID to use for SDA */ >>> unsigned int scl_pin; /* GPIO pin ID to use for SCL */ >>> + bool has_pfunc; /*chip has a ICPFUNC register */ >> Space after /* please >> > regards, > -grygorii > > > From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Looijmans Subject: Re: [5/5] i2c: davinci: use ICPFUNC to toggle I2C as gpio for bus recovery Date: Mon, 24 Nov 2014 19:13:06 +0100 Message-ID: <54737532.1050808@milosoftware.com> References: <1416477788-5544-6-git-send-email-grygorii.strashko@ti.com> <20141123170400.GC4431@pengutronix.de> <54732F8E.4080105@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <54732F8E.4080105-l0cyMroinI0@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Grygorii Strashko , =?windows-1252?Q?Uwe_?= =?windows-1252?Q?Kleine-K=F6nig?= Cc: Wolfram Sang , linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Sekhar Nori , Kevin Hilman , Santosh Shilimkar , Murali Karicheri , Ben Gardiner , Mike Looijmans List-Id: linux-i2c@vger.kernel.org On 24-11-2014 14:15, Grygorii Strashko wrote: > Hi Uwe, > On 11/23/2014 07:04 PM, Uwe Kleine-K=F6nig wrote: >> On Thu, Nov 20, 2014 at 12:03:08PM +0200, Grygorii Strashko wrote: >>> @@ -664,6 +759,7 @@ static int davinci_i2c_probe(struct platform_de= vice *pdev) >>> if (!of_property_read_u32(pdev->dev.of_node, "clock-frequency"= , >>> &prop)) >>> dev->pdata->bus_freq =3D prop / 1000; >>> + dev->pdata->has_pfunc =3D true; >> I don't understand this. Why does this ICPFUNC recovery work if the = bus >> is probed by oftree, but doesn't if not? > I've mentioned this in commit message: > Allow platforms to indicate the presence of the ICPFUNC registers w= ith a has_pfunc > platform data flag and enable this mode for platforms which support= s DT (da850 and > Keystone 2 are two SoCs which support DT now and they also support = ICPFUNC registers). > > I'll add proper comment here. Just thinking: What happens if you try to use the ICPFUNC registers on=20 platforms that don't support it? If the answer is "nothing bad", then=20 you might as well assume that if the platform doesn't specify its own=20 GPIOs, you can always try using the ICPFUNC registers to shake the I2C=20 bus. Better to try and fail than to never try at all... > >>> } else if (!dev->pdata) { >>> dev->pdata =3D &davinci_i2c_platform_data_default; >>> } >>> @@ -705,7 +801,9 @@ static int davinci_i2c_probe(struct platform_de= vice *pdev) >>> adap->timeout =3D DAVINCI_I2C_TIMEOUT; >>> adap->dev.of_node =3D pdev->dev.of_node; >>> =20 >>> - if (dev->pdata->scl_pin) { >>> + if (dev->pdata->has_pfunc) >>> + adap->bus_recovery_info =3D &davinci_i2c_scl_recovery_info; >>> + else if (dev->pdata->scl_pin) { >>> adap->bus_recovery_info =3D &davinci_i2c_gpio_recovery_info; >>> adap->bus_recovery_info->scl_gpio =3D dev->pdata->scl_pin; >>> adap->bus_recovery_info->sda_gpio =3D dev->pdata->sda_pin; >>> diff --git a/include/linux/platform_data/i2c-davinci.h b/include/li= nux/platform_data/i2c-davinci.h >>> index 2312d19..89fd347 100644 >>> --- a/include/linux/platform_data/i2c-davinci.h >>> +++ b/include/linux/platform_data/i2c-davinci.h >>> @@ -18,6 +18,7 @@ struct davinci_i2c_platform_data { >>> unsigned int bus_delay; /* post-transaction delay (usec) */ >>> unsigned int sda_pin; /* GPIO pin ID to use for SDA *= / >>> unsigned int scl_pin; /* GPIO pin ID to use for SCL *= / >>> + bool has_pfunc; /*chip has a ICPFUNC register */ >> Space after /* please >> > regards, > -grygorii > > >