From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753046AbbKBJNI (ORCPT ); Mon, 2 Nov 2015 04:13:08 -0500 Received: from mail-wm0-f48.google.com ([74.125.82.48]:38867 "EHLO mail-wm0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751677AbbKBJM6 (ORCPT ); Mon, 2 Nov 2015 04:12:58 -0500 Date: Mon, 2 Nov 2015 09:12:53 +0000 From: Lee Jones To: Damien Riegel Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-watchdog@vger.kernel.org, shawnguo@kernel.org, kernel@pengutronix.de, wim@iguana.be, robh+dt@kernel.org, sameo@linux.intel.com, dinh.linux@gmail.com, linux@roeck-us.net, kernel@savoirfairelinux.com, arnd@arndb.de Subject: Re: [PATCH v2 2/5] mfd: ts4800-syscon: add driver for TS-4800 syscon Message-ID: <20151102091253.GS4058@x1> References: <1446150450-22093-1-git-send-email-damien.riegel@savoirfairelinux.com> <1446150450-22093-3-git-send-email-damien.riegel@savoirfairelinux.com> <20151030175656.GF4058@x1> <20151030200812.GB8666@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20151030200812.GB8666@localhost> 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 [Cc'ing Arnd] On Fri, 30 Oct 2015, Damien Riegel wrote: > On Fri, Oct 30, 2015 at 05:56:56PM +0000, Lee Jones wrote: > > On Thu, 29 Oct 2015, Damien Riegel wrote: > > > > > Driver for TS-4800 syscon. These registers belong to a FPGA that is > > > memory mapped and are used for counters, enable various IPs in the FPGA, > > > control LEDs, control IOs, etc. > > > > > > Currently, only the watchdog is handled. > > > > Why do you require your own syscon driver? > > > > What's wrong with the generic one? > > > > The generic one uses a regmap_config with reg_stride set to 4 and val_bits > to 32. > > TS-4800 syscon registers are 16-bit wide and must be accessed with 16 > bit read and writes: > http://wiki.embeddedarm.com/wiki/TS-4800#Syscon > > I will address the other issues in the next version (split commit, > license issue, style, and superfluous remove). The Syscon driver was written to be generic so that each vendor/platform didn't require their own incarnation. How unique is the TS-4800? Perhaps it might be better to supply a generic 16 bit Syscon for devices akin to the TS-4800? Arnd, any opinion on this? > > > Signed-off-by: Damien Riegel > > > --- > > > .../devicetree/bindings/mfd/ts4800-syscon.txt | 12 ++++ > > > > Separate patch please. > > > > > drivers/mfd/Kconfig | 7 ++ > > > drivers/mfd/Makefile | 1 + > > > drivers/mfd/ts4800-syscon.c | 84 ++++++++++++++++++++++ > > > include/linux/mfd/ts4800-syscon.h | 24 +++++++ > > > 5 files changed, 128 insertions(+) > > > create mode 100644 Documentation/devicetree/bindings/mfd/ts4800-syscon.txt > > > create mode 100644 drivers/mfd/ts4800-syscon.c > > > create mode 100644 include/linux/mfd/ts4800-syscon.h > > > > > > diff --git a/Documentation/devicetree/bindings/mfd/ts4800-syscon.txt b/Documentation/devicetree/bindings/mfd/ts4800-syscon.txt > > > new file mode 100644 > > > index 0000000..8dbc12c > > > --- /dev/null > > > +++ b/Documentation/devicetree/bindings/mfd/ts4800-syscon.txt > > > @@ -0,0 +1,12 @@ > > > +Technologic Systems Syscon > > > + > > > +Required properties: > > > +- compatible : must be "ts,ts4800-syscon" > > > +- reg : physical base address and length of memory mapped region > > > + > > > +Example: > > > + > > > +syscon@b0010000 { > > > + compatible = "ts,ts4800-syscon"; > > > + reg = <0xb0010000 0x3d>; > > > +}; > > > diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig > > > index 3f68dd2..8f03dce 100644 > > > --- a/drivers/mfd/Kconfig > > > +++ b/drivers/mfd/Kconfig > > > @@ -1302,6 +1302,13 @@ config MFD_TC6393XB > > > help > > > Support for Toshiba Mobile IO Controller TC6393XB > > > > > > +config MFD_TS4800_SYSCON > > > + tristate "TS-4800 Syscon Support" > > > + select REGMAP > > > + select REGMAP_MMIO > > > + help > > > + Support for TS-4800's FPGA Syscon registers > > > + > > > config MFD_VX855 > > > tristate "VIA VX855/VX875 integrated south bridge" > > > depends on PCI > > > diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile > > > index ea40e07..e2c0f1b 100644 > > > --- a/drivers/mfd/Makefile > > > +++ b/drivers/mfd/Makefile > > > @@ -181,6 +181,7 @@ obj-$(CONFIG_MFD_HI6421_PMIC) += hi6421-pmic-core.o > > > obj-$(CONFIG_MFD_DLN2) += dln2.o > > > obj-$(CONFIG_MFD_RT5033) += rt5033.o > > > obj-$(CONFIG_MFD_SKY81452) += sky81452.o > > > +obj-$(CONFIG_MFD_TS4800_SYSCON) += ts4800-syscon.o > > > > > > intel-soc-pmic-objs := intel_soc_pmic_core.o intel_soc_pmic_crc.o > > > obj-$(CONFIG_INTEL_SOC_PMIC) += intel-soc-pmic.o > > > diff --git a/drivers/mfd/ts4800-syscon.c b/drivers/mfd/ts4800-syscon.c > > > new file mode 100644 > > > index 0000000..1e42e96 > > > --- /dev/null > > > +++ b/drivers/mfd/ts4800-syscon.c > > > @@ -0,0 +1,84 @@ > > > +/* > > > + * Device driver for TS-4800 FPGA's syscon > > > + * > > > + * Copyright (c) 2015 - Savoir-faire Linux > > > + * > > > + * This program is free software; you can redistribute it and/or modify > > > + * it under the terms of the GNU General Public License as published by > > > + * the Free Software Foundation; either version 2 of the License, or > > > + * (at your option) any later version. > > > > Why is the MFD v2+ and the Watchdog driver only v2? > > > > > + * This program is distributed in the hope it will be useful, but WITHOUT > > > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or > > > + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for > > > + * more details. > > > + */ > > > + > > > +#include > > > +#include > > > +#include > > > +#include > > > +#include > > > +#include > > > +#include > > > +#include > > > > Alphabetical. > > > > > + > > > + > > > > Superfluous '\n'. > > > > > +static const struct regmap_config ts4800_regmap_config = { > > > + .reg_bits = 32, > > > + .reg_stride = 2, > > > + .val_bits = 16, > > > +}; > > > + > > > +static int ts4800_syscon_probe(struct platform_device *pdev) > > > +{ > > > + struct ts4800_syscon *syscon; > > > + struct resource *res; > > > + void __iomem *base; > > > + > > > + syscon = devm_kzalloc(&pdev->dev, sizeof(*syscon), GFP_KERNEL); > > > + if (!syscon) > > > + return -ENOMEM; > > > + > > > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > > > + base = devm_ioremap_resource(&pdev->dev, res); > > > + if (IS_ERR(base)) > > > + return PTR_ERR(base); > > > + > > > + syscon->regmap = devm_regmap_init_mmio_clk(&pdev->dev, NULL, base, > > > + &ts4800_regmap_config); > > > + if (IS_ERR(syscon->regmap)) { > > > + dev_err(&pdev->dev, > > > + "regmap init failed: %ld\n", > > > + PTR_ERR(syscon->regmap)); > > > + return PTR_ERR(syscon->regmap); > > > + } > > > + > > > + platform_set_drvdata(pdev, syscon); > > > + > > > + return 0; > > > +} > > > + > > > +static int ts4800_syscon_remove(struct platform_device *pdev) > > > +{ > > > + return 0; > > > +} > > > > If it doesn't do anything, don't provide it. > > > > > +static const struct of_device_id ts4800_syscon_of_match[] = { > > > + { .compatible = "ts,ts4800-syscon", }, > > > + { }, > > > +}; > > > + > > > +static struct platform_driver ts4800_syscon_driver = { > > > + .driver = { > > > + .name = "ts4800_syscon", > > > + .of_match_table = ts4800_syscon_of_match, > > > + }, > > > + .probe = ts4800_syscon_probe, > > > + .remove = ts4800_syscon_remove, > > > +}; > > > +module_platform_driver(ts4800_syscon_driver); > > > + > > > +MODULE_AUTHOR("Damien Riegel "); > > > +MODULE_DESCRIPTION("TS-4800 Syscon driver"); > > > +MODULE_LICENSE("GPL v2"); > > > > This does not match the header. > > > > > diff --git a/include/linux/mfd/ts4800-syscon.h b/include/linux/mfd/ts4800-syscon.h > > > new file mode 100644 > > > index 0000000..3d29184 > > > --- /dev/null > > > +++ b/include/linux/mfd/ts4800-syscon.h > > > @@ -0,0 +1,24 @@ > > > +/* > > > + * Copyright (c) 2015 - Savoir-faire Linux > > > + * > > > + * This program is free software; you can redistribute it and/or modify > > > + * it under the terms of the GNU General Public License as published by > > > + * the Free Software Foundation; either version 2 of the License, or > > > + * (at your option) any later version. > > > + * > > > + * This program is distributed in the hope it will be useful, but WITHOUT > > > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or > > > + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for > > > + * more details. > > > + */ > > > + > > > +#ifndef __LINUX_MFD_TS4800_SYSCON_H > > > +#define __LINUX_MFD_TS4800_SYSCON_H > > > + > > > +#include > > > + > > > +struct ts4800_syscon { > > > + struct regmap *regmap; > > > +}; > > > + > > > +#endif /* __LINUX_MFD_TS4800_SYSCON_H */ > > -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog