Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932186AbbG1LHZ (ORCPT ); Tue, 28 Jul 2015 07:07:25 -0400 Received: from mail-wi0-f178.google.com ([209.85.212.178]:37665 "EHLO mail-wi0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755274AbbG1LHV (ORCPT ); Tue, 28 Jul 2015 07:07:21 -0400 Date: Tue, 28 Jul 2015 12:07:17 +0100 From: Matt Fleming To: Lee Jones Cc: Wim Van Sebroeck , linux-kernel@vger.kernel.org, linux-watchdog@vger.kernel.org, Mika Westerberg , Andy Shevchenko , Jean Delvare , Wolfram Sang , Matt Fleming , Peter Tyser , Samuel Ortiz , Aaron Sierra Subject: Re: [PATCH 1/5] iTCO_wdt: Expose watchdog properties using platform data Message-ID: <20150728110717.GH2492@codeblueprint.co.uk> References: <1438004292-16382-1-git-send-email-matt@codeblueprint.co.uk> <1438004292-16382-2-git-send-email-matt@codeblueprint.co.uk> <20150728094643.GT14943@x1> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150728094643.GT14943@x1> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5813 Lines: 162 On Tue, 28 Jul, at 10:46:43AM, Lee Jones wrote: > On Mon, 27 Jul 2015, Matt Fleming wrote: > > > From: Matt Fleming > > > > Intel Sunrisepoint (Skylake PCH) has the iTCO watchdog accessible across > > the SMBus, unlike previous generations of PCH/ICH where it was on the > > LPC bus. Because it's on the SMBus, it doesn't make sense to pass around > > a 'struct lpc_ich_info', and leaking the type of bus into the iTCO > > watchdog driver is kind of backwards anyway. > > > > This change introduces a new 'struct iTCO_wdt_platform_data' for use > > inside the iTCO watchdog driver and by the upcoming Intel Sunrisepoint > > code, which neatly avoids having to include lpc_ich headers in the i801 > > i2c driver. > > > > A simple translation layer is provided for converting from the existing > > 'struct lpc_ich_info' inside the lpc_ich mfd driver. > > > > Cc: Peter Tyser > > Cc: Samuel Ortiz > > Cc: Lee Jones > > Cc: Wim Van Sebroeck > > Signed-off-by: Matt Fleming > > --- > > drivers/mfd/lpc_ich.c | 32 +++++++++++++++++++++++++++++--- > > drivers/watchdog/Kconfig | 2 +- > > drivers/watchdog/iTCO_wdt.c | 11 +++++------ > > include/linux/mfd/lpc_ich.h | 6 ------ > > include/linux/platform_data/iTCO_wdt.h | 18 ++++++++++++++++++ > > 5 files changed, 53 insertions(+), 16 deletions(-) > > create mode 100644 include/linux/platform_data/iTCO_wdt.h > > > > diff --git a/drivers/mfd/lpc_ich.c b/drivers/mfd/lpc_ich.c > > index 8de34398abc0..d190b74a6321 100644 > > --- a/drivers/mfd/lpc_ich.c > > +++ b/drivers/mfd/lpc_ich.c > > @@ -66,6 +66,7 @@ > > #include > > #include > > #include > > +#include > > Lowercase please. Even though the driver is called iTCO_wdt? It seemed to me to be more confusing to start mixing cases rather than sticking with the ugly upper case. Especially since when you look in the iTCO_wdt driver all the function and type names are written that way. > > #define ACPIBASE 0x40 > > #define ACPIBASE_GPE_OFF 0x28 > > @@ -835,9 +836,31 @@ static void lpc_ich_enable_pmc_space(struct pci_dev *dev) > > priv->actrl_pbase_save = reg_save; > > } > > > > -static void lpc_ich_finalize_cell(struct pci_dev *dev, struct mfd_cell *cell) > > +static int lpc_ich_finalize_wdt_cell(struct pci_dev *dev) > > { > > + struct iTCO_wdt_platform_data *pdata; > > Lowercase please. See above. > > struct lpc_ich_priv *priv = pci_get_drvdata(dev); > > + struct lpc_ich_info *info; > > + struct mfd_cell *cell = &lpc_ich_cells[LPC_WDT]; > > + > > + pdata = kzalloc(sizeof(*pdata), GFP_KERNEL); > > + if (!pdata) > > + return -ENOMEM; > > Where is this freed? > > Better to use devm_* Yeah, Guenter caught this too. devm_* would definitely be better. > > + info = &lpc_chipset_info[priv->chipset]; > > + > > + pdata->iTCO_version = info->iTCO_version; > > Lowercase please. Hmm... but then this line will read, pdata->itco_version = info->iTCO_version; I'm not sure that's an improvement. > > > + strcpy(pdata->name, info->name); > > strncpy() is safer. OK, I'll update this. Though it's worth pointing out that the name[] declarations are of identical size in these two objects (but I guess that could change in the future). > > + cell->platform_data = pdata; > > + cell->pdata_size = sizeof(*pdata); > > + return 0; > > +} > > + > > +static void lpc_ich_finalize_gpio_cell(struct pci_dev *dev) > > +{ > > + struct lpc_ich_priv *priv = pci_get_drvdata(dev); > > + struct mfd_cell *cell = &lpc_ich_cells[LPC_GPIO]; > > > > cell->platform_data = &lpc_chipset_info[priv->chipset]; > > cell->pdata_size = sizeof(struct lpc_ich_info); > > It's pretty hard to tell from the patch without applying it, but what > are the actual similarities and differences between the two finalise > functions? They looks like they share enough lines for it to make > sense to have one function call and do different things in say a > switch statement, no? For LPC_WDT we dynamically allocate the platform data, and for LPC_GPIO we use the static lpc_chipsec_info array. I'm just personally not a fan of performing memory allocations from within switch statement bodies, which is why I implemented this as two separate finalize functions. > > @@ -933,7 +956,7 @@ gpe0_done: > > lpc_chipset_info[priv->chipset].use_gpio = ret; > > lpc_ich_enable_gpio_space(dev); > > > > - lpc_ich_finalize_cell(dev, &lpc_ich_cells[LPC_GPIO]); > > + lpc_ich_finalize_gpio_cell(dev); > > ret = mfd_add_devices(&dev->dev, PLATFORM_DEVID_AUTO, > > &lpc_ich_cells[LPC_GPIO], 1, NULL, 0, NULL); > > > > @@ -1007,7 +1030,10 @@ static int lpc_ich_init_wdt(struct pci_dev *dev) > > res->end = base_addr + ACPIBASE_PMC_END; > > } > > > > - lpc_ich_finalize_cell(dev, &lpc_ich_cells[LPC_WDT]); > > + ret = lpc_ich_finalize_wdt_cell(dev); > > + if (ret) > > + goto wdt_done; > > + > > ret = mfd_add_devices(&dev->dev, PLATFORM_DEVID_AUTO, > > &lpc_ich_cells[LPC_WDT], 1, NULL, 0, NULL); > > Why do you have an mfd_add_devices() call for each device? Good question. This call has been present since March 2012 when support was first added for iTCO_wdt in commit 887c8ec7219f ("watchdog: Convert iTCO_wdt driver to mfd model"). There's no good reason that I can see. Aaron? -- Matt Fleming, Intel Open Source Technology Center -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/