From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A3420C433E0 for ; Mon, 22 Jun 2020 10:55:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 709C7206FA for ; Mon, 22 Jun 2020 10:55:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="MqPCIqVf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727914AbgFVKzx (ORCPT ); Mon, 22 Jun 2020 06:55:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52280 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727805AbgFVKzu (ORCPT ); Mon, 22 Jun 2020 06:55:50 -0400 Received: from mail-wr1-x443.google.com (mail-wr1-x443.google.com [IPv6:2a00:1450:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E5EE0C061794 for ; Mon, 22 Jun 2020 03:55:48 -0700 (PDT) Received: by mail-wr1-x443.google.com with SMTP id x6so16152088wrm.13 for ; Mon, 22 Jun 2020 03:55:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=KoWfZGUWw5C18ooOV0MLNeymXgRwlrvLzPcWKgUELZ8=; b=MqPCIqVfeX6FnZR0P6Nv/pkU/Oo/r0qpdBVkZ41DKtClDNp2XknFMQblxt6Kl4dOLf 500zLlXFEy7KVKZbNIyzTbGNL1FbqwZeuw5h2neOFh9FU+hFKFVoHMrebkUMRS7NSCnf /Iep0kf+yLJ7awueDHIC9Qd1hkolYp1hIpg/iyOAbK6Lnd92wZ8sy/rYW9+wYz0i0jg+ Wa75paKy6HV6VvhOnYDFIPxB1IFJxktZmHTgch1QVs/FZl/5aZ5koo9CYDQCiTC6+Aor 9cqRS/n4IqkLdeBVrK9GjEPtlvYUM/t7ygvmJ3LdUMEZ34Bo/eI4jG4LQQpddCqALScL NtPQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=KoWfZGUWw5C18ooOV0MLNeymXgRwlrvLzPcWKgUELZ8=; b=h4WHUwbBtEWfWFhbK8q3LibWIWdLB9QaKYtPm+VTjO2HVDh/CCcgvDXCaNbsYNN7dW ++msOttAyMe+CkG1/5TJbItwxraOlSFpKAme/oitMi6DjDaBWYqz/XFUT1mL9UHU4Ql5 TeTnDbAjqmfMU2iBbdUInG4JWmL6EoU3nrbdcQ6epYQD4/ZyFjzHmQwnbUziAFbUuLjM KXfYw3aqy27hNOPX4PJKwj3o6XEmwC2LdjknWEiK7i0JtnCX29USllw+FMCIAbiFYZS9 A9dpp9GgMh6ayaqVpDTOnWPd1MaWNcFtTGoid75wdUs2Fw11V5yig0y9K61dwNrJ2bni IYkg== X-Gm-Message-State: AOAM532kpknL3K2EiUUjydzgEztzdPkmqEszur4ER4Z3G1T5uUxngg6G A7U3HS7nHUPabhaO0gKMOuza3A== X-Google-Smtp-Source: ABdhPJwUK4AwBpQhsM0+AFV5S7K5kK/5FkSGHnjSyKX7rVYVRGIgnKd20aMohuBX+6UliHE+X1ez0A== X-Received: by 2002:adf:9286:: with SMTP id 6mr18654037wrn.361.1592823347358; Mon, 22 Jun 2020 03:55:47 -0700 (PDT) Received: from dell ([2.27.35.144]) by smtp.gmail.com with ESMTPSA id c20sm10890766wrb.65.2020.06.22.03.55.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 22 Jun 2020 03:55:46 -0700 (PDT) Date: Mon, 22 Jun 2020 11:55:44 +0100 From: Lee Jones To: Jonathan =?iso-8859-1?Q?Neusch=E4fer?= Cc: linux-kernel@vger.kernel.org, Rob Herring , Thierry Reding , Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= , Alessandro Zummo , Alexandre Belloni , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , NXP Linux Team , Sam Ravnborg , Linus Walleij , Heiko Stuebner , Stephan Gerhold , Lubomir Rintel , Mark Brown , allen , Mauro Carvalho Chehab , "David S. Miller" , devicetree@vger.kernel.org, linux-pwm@vger.kernel.org, linux-rtc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Heiko Stuebner , Josua Mayer , Andreas Kemnade Subject: Re: [RFC PATCH 04/10] mfd: Add base driver for Netronix embedded controller Message-ID: <20200622105544.GU954398@dell> References: <20200620224222.1312520-1-j.neuschaefer@gmx.net> <20200620224222.1312520-3-j.neuschaefer@gmx.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20200620224222.1312520-3-j.neuschaefer@gmx.net> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 21 Jun 2020, Jonathan Neuschäfer wrote: Description of the device here please. > Third-party hardware documentation is available at '\n' > https://github.com/neuschaefer/linux/wiki/Netronix-MSP430-embedded-controller Indent this with a couple of spaces. > The EC supports interrupts, but the driver doesn't make use of them so > far. > > Known problems: > - The reboot handler is installed in such a way that it directly calls > into the i2c subsystem to send the reboot command to the EC. This > means that the reboot handler may sleep, which is not allowed. > > Signed-off-by: Jonathan Neuschäfer > --- > drivers/mfd/Kconfig | 7 ++ > drivers/mfd/Makefile | 1 + > drivers/mfd/ntxec.c | 188 ++++++++++++++++++++++++++++++++++++++ > include/linux/mfd/ntxec.h | 30 ++++++ > 4 files changed, 226 insertions(+) > create mode 100644 drivers/mfd/ntxec.c > create mode 100644 include/linux/mfd/ntxec.h > > diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig > index a37d7d1713820..78410b928648e 100644 > --- a/drivers/mfd/Kconfig > +++ b/drivers/mfd/Kconfig > @@ -978,6 +978,13 @@ config MFD_VIPERBOARD > You need to select the mfd cell drivers separately. > The drivers do not support all features the board exposes. > > +config MFD_NTXEC > + bool "Netronix Embedded Controller" > + depends on I2C && OF > + help > + Say yes here if you want to support the embedded controller of > + certain e-book readers designed by the ODM Netronix. s/of certain/found in certain/. > config MFD_RETU > tristate "Nokia Retu and Tahvo multi-function device" > select MFD_CORE > diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile > index 9367a92f795a6..19d9391ed6f32 100644 > --- a/drivers/mfd/Makefile > +++ b/drivers/mfd/Makefile > @@ -218,6 +218,7 @@ obj-$(CONFIG_MFD_INTEL_MSIC) += intel_msic.o > obj-$(CONFIG_MFD_INTEL_PMC_BXT) += intel_pmc_bxt.o > obj-$(CONFIG_MFD_PALMAS) += palmas.o > obj-$(CONFIG_MFD_VIPERBOARD) += viperboard.o > +obj-$(CONFIG_MFD_NTXEC) += ntxec.o > obj-$(CONFIG_MFD_RC5T583) += rc5t583.o rc5t583-irq.o > obj-$(CONFIG_MFD_RK808) += rk808.o > obj-$(CONFIG_MFD_RN5T618) += rn5t618.o > diff --git a/drivers/mfd/ntxec.c b/drivers/mfd/ntxec.c > new file mode 100644 > index 0000000000000..82adea34ea746 > --- /dev/null > +++ b/drivers/mfd/ntxec.c > @@ -0,0 +1,188 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +// Copyright 2020 Jonathan Neuschäfer > +// > +// MFD driver for the usually MSP430-based embedded controller used in certain > +// Netronix ebook reader board designs Only the SPDX line should contain C++ style comments. Description at the top, copyright after. An "MFD driver" isn't really a thing. Please describe the device. > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > + No need for double line spacing. > +#define NTXEC_VERSION 0x00 > +#define NTXEC_POWEROFF 0x50 > +#define NTXEC_POWERKEEP 0x70 > +#define NTXEC_RESET 0x90 Are these registers? Might be worth pre/post-fixing with _REG. > +/* Register access */ > + > +int ntxec_read16(struct ntxec *ec, u8 addr) > +{ > + u8 request[1] = { addr }; > + u8 response[2]; > + int res; > + > + struct i2c_msg msgs[] = { > + { > + .addr = ec->client->addr, > + .flags = ec->client->flags, > + .len = sizeof(request), > + .buf = request > + }, { > + .addr = ec->client->addr, > + .flags = ec->client->flags | I2C_M_RD, > + .len = sizeof(response), > + .buf = response > + } > + }; > + > + res = i2c_transfer(ec->client->adapter, msgs, ARRAY_SIZE(msgs)); > + if (res < 0) > + return res; > + if (res != ARRAY_SIZE(msgs)) > + return -EIO; > + > + return get_unaligned_be16(response); > +} > +EXPORT_SYMBOL(ntxec_read16); > + > +int ntxec_write16(struct ntxec *ec, u8 addr, u16 value) > +{ > + u8 request[3] = { addr, }; > + int res; > + > + put_unaligned_be16(value, request + 1); > + > + res = i2c_transfer_buffer_flags(ec->client, request, sizeof(request), > + ec->client->flags); > + if (res < 0) > + return res; > + > + return 0; > +} > +EXPORT_SYMBOL(ntxec_write16); > + > +int ntxec_read8(struct ntxec *ec, u8 addr) > +{ > + int res = ntxec_read16(ec, addr); > + > + if (res < 0) > + return res; > + > + return (res >> 8) & 0xff; > +} > +EXPORT_SYMBOL(ntxec_read8); > + > +int ntxec_write8(struct ntxec *ec, u8 addr, u8 value) > +{ > + return ntxec_write16(ec, addr, value << 8); > +} > +EXPORT_SYMBOL(ntxec_write8); Why are you hand-rolling your own accessors? > + > + > +/* Reboot/poweroff handling */ These comments seem to be stating the obvious. Please remove them. > +static struct ntxec *poweroff_restart_instance; > + > +static void ntxec_poweroff(void) > +{ > + ntxec_write8(poweroff_restart_instance, NTXEC_POWEROFF, 0x01); All magic numbers should be defined? > + msleep(5000); Why 5000? > +} > + > +static int ntxec_restart(struct notifier_block *nb, > + unsigned long action, void *data) > +{ > + /* FIXME: The I2C driver sleeps, but restart handlers may not sleep */ Then this is not allowed. You need to fix this *before* submitting upstream. > + ntxec_write8(poweroff_restart_instance, NTXEC_RESET, 0xff); > + /* TODO: delay? */ TODO *before* submitting upstream. This is not a development branch. > + return NOTIFY_DONE; > +} > + > +static struct notifier_block ntxec_restart_handler = { > + .notifier_call = ntxec_restart, > + .priority = 128 > +}; > + > + > +/* Driver setup */ > + > +static int ntxec_probe(struct i2c_client *client, > + const struct i2c_device_id *ids) > +{ > + struct ntxec *ec; > + int res; What does 'res' mean? > + ec = devm_kmalloc(&client->dev, sizeof(*ec), GFP_KERNEL); > + if (!ec) > + return -ENOMEM; > + > + ec->dev = &client->dev; > + ec->client = client; You don't need both (if any). > + /* Determine the firmware version */ > + res = ntxec_read16(ec, NTXEC_VERSION); > + if (res < 0) { > + dev_dbg(ec->dev, "Failed to read firmware version number\n"); Why dbg? > + return res; > + } > + ec->version = res; > + > + dev_info(ec->dev, > + "Netronix embedded controller version %04x detected.\n", > + ec->version); > + > + /* For now, we don't support the new register layout. */ > + if (ntxec_has_new_layout(ec)) > + return -EOPNOTSUPP; What is the new layout? Why don't you support it? > + if (of_device_is_system_power_controller(ec->dev->of_node)) { > + /* > + * Set the 'powerkeep' bit. This is necessary on some boards > + * in order to keep the system running. > + */ > + res = ntxec_write8(ec, NTXEC_POWERKEEP, 0x08); > + if (res < 0) > + return res; > + > + /* Install poweroff handler */ > + WARN_ON(poweroff_restart_instance); Why WARN? > + poweroff_restart_instance = ec; > + if (pm_power_off != NULL) if (pm_power_off) > + /* TODO: Refactor among all poweroff drivers */ Nope. > + dev_err(ec->dev, "pm_power_off already assigned\n"); Error, but execution carries on anyway? > + else > + pm_power_off = ntxec_poweroff; > + > + /* Install board reset handler */ > + res = register_restart_handler(&ntxec_restart_handler); > + if (res < 0) Is >0 valid? > + dev_err(ec->dev, > + "Failed to register restart handler: %d\n", res); > + } > + > + i2c_set_clientdata(client, ec); Where do you use this? > + return devm_of_platform_populate(ec->dev); > +} > + > +static const struct of_device_id of_ntxec_match_table[] = { > + { .compatible = "netronix,ntxec", }, > + {} > +}; Use .probe_new() and drop this. > +static struct i2c_driver ntxec_driver = { > + .driver = { > + .name = "ntxec", > + .of_match_table = of_ntxec_match_table, > + }, > + .probe = ntxec_probe, Nothing to .remove()? > +}; > +builtin_i2c_driver(ntxec_driver); Only built-in? > diff --git a/include/linux/mfd/ntxec.h b/include/linux/mfd/ntxec.h > new file mode 100644 > index 0000000000000..9f9d6f2141751 > --- /dev/null > +++ b/include/linux/mfd/ntxec.h > @@ -0,0 +1,30 @@ > +/* SPDX-License-Identifier: GPL-2.0-only */ > +/* > + * Copyright 2020 Jonathan Neuschäfer > + * > + * MFD access functions for the Netronix embedded controller. No such thing as an MFD. "Embedded Controller" > + */ > + > +#ifndef NTXEC_H > +#define NTXEC_H > + > +#include > + > +struct ntxec { > + struct device *dev; > + struct i2c_client *client; > + u16 version; > + /* TODO: Add a mutex to protect actions consisting of multiple accesses? */ No TODOs. Please fix before upstreaming. > +}; > + > +static inline bool ntxec_has_new_layout(struct ntxec *ec) > +{ > + return ec->version == 0xe916; Why don't you just check for the devices you *do* support? > +} > + > +int ntxec_read16(struct ntxec *ec, u8 addr); > +int ntxec_write16(struct ntxec *ec, u8 addr, u16 value); > +int ntxec_read8(struct ntxec *ec, u8 addr); > +int ntxec_write8(struct ntxec *ec, u8 addr, u8 value); > + > +#endif #endif /* NTXEC_H */ -- Lee Jones [李琼斯] Senior Technical Lead - Developer Services Linaro.org │ Open source software for Arm SoCs Follow Linaro: Facebook | Twitter | Blog