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=-20.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 46397C433E0 for ; Sat, 9 Jan 2021 18:07:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 11528239FE for ; Sat, 9 Jan 2021 18:07:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726058AbhAISHX (ORCPT ); Sat, 9 Jan 2021 13:07:23 -0500 Received: from mout.gmx.net ([212.227.15.18]:53667 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725951AbhAISHX (ORCPT ); Sat, 9 Jan 2021 13:07:23 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1610215502; bh=Tuw+ZgZ4Kq1PeWeeWse0O4WWhQIH6noWqKgzE61zkGs=; h=X-UI-Sender-Class:From:To:Cc:Subject:Date:In-Reply-To:References; b=bOCP+GslRwX4m8cumG51YSJtXjf7QCBOeRUi72FQueIspwYsZmNU9uCrHk9v/CBa2 FaDAnADGylGYpgESRp1zR4rgZEgMHWzzjYhQTgAYIzT24pLr7APcbJ2+KZwFL/OqaC Iigpbmy9i9v+rLF7jYW3GS69hOfN1YNOb348n81c= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from longitude ([37.201.215.57]) by mail.gmx.com (mrgmx005 [212.227.17.190]) with ESMTPSA (Nemesis) id 1MEFvj-1kqIOp20LV-00ACNe; Sat, 09 Jan 2021 19:05:02 +0100 From: =?UTF-8?q?Jonathan=20Neusch=C3=A4fer?= To: linux-kernel@vger.kernel.org Cc: Lee Jones , Rob Herring , =?UTF-8?q?Jonathan=20Neusch=C3=A4fer?= , Thierry Reding , =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= , 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 , Arnd Bergmann , Daniel Palmer , Andy Shevchenko Subject: [PATCH v7 3/7] mfd: Add base driver for Netronix embedded controller Date: Sat, 9 Jan 2021 19:02:16 +0100 Message-Id: <20210109180220.121511-4-j.neuschaefer@gmx.net> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210109180220.121511-1-j.neuschaefer@gmx.net> References: <20210109180220.121511-1-j.neuschaefer@gmx.net> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:foAsmsgdOWTVSw/YGXc2EruSMnsyjwSVlFx6zJqHEmmTVsft2cm yfQgPRN/LxWFvUEvPLkF6DnhMf7PBYWP+y9vCYJi0do+69/7BYePPvw2iCSCTItLsv35qjS hFd16QTidEyNTsVPJmja/a0/q3dcFGZRc0AWcYJs6LI+ABSyFxZmrACsCUH33OHAzs/1yK/ +lH1OO1Kkoi+vZ77NxJjQ== X-UI-Out-Filterresults: notjunk:1;V03:K0:SQ9O/0aZvnQ=:xbrVD/GkkcvZtLsCs/nDs5 l7oXyzhJhgYh6c8D9dgJko6MfJ+p7JiL6Md6nscLi+YsY+alj+AXHU6lMdrUVD7KUPUmsj9Dn U9b3t8w8CZQZ/V8yldEl4IQWyfqSEghZ2Oay4VVOvnss+qn/vJyCKa5Mu5AokGKWXbTiQQhkc dwo+vJkLcyP2PQ1OKFVEfEUkCNOdOT872ougp8f6Dqa7MO1f+4bkwkGblHAnNpIrguPPsv8O2 2gGiGhBjL2Ihx9JHmTjNhhTBAOrKJmXL99vWWxjjvIR57XSzneom+WxYMOKD/tuzbvAwkb+fu nrTMgSLxlhyWjNOuoLU0w2XHqjZM/bvRkR5/AO4EWZ2CsOOpkWEkqSBU0CckWgkpnPgNxHHdn 2n62OZrubD5MPvUFeqFTEdF3H1YEOKyN5oyUF+nUGWFfPmGQfKzjywE/LOLWL28pKmPPy3xqQ ekBAUFnnXvqgvM2hjSy71GMBCmi/zWGWo+abM+hGtX3XAiFbsIVroR+ggDRfSmKRDsdvJlAEG HuI1Oxvf4W8gOclG9dTrCZHhHuDwuYFwsWYhjmp+A80XRLyAxwk8ghioqjRC2JlmPvvGkV5ea 7k4wfSiZoswrDvgW1GTsQlUJBPO1PS4hChDqClA7QB5m/ZcsEkn6Yk84kRAC5qapj92r0kjoy JEfFGgMLJaRWHnNOnFpZV9yWxTovgQ/QePvMeDieemWrT0txhrGz2uHwSV9I1pqk6ycgb0+IH ZmuV2+xO/b8y7h0qcQGCBrRoNQdHWX1gY0dEkirXr7SNYNHUUopoR2yinT7NvHr7tzGMLdYTa yBHVsSrYZxgDcRPqB7/RzOPLkTULzx/5YffvuTarbm+u7chDzr4et8svoX5a4VuQ1Yr4jZ5mj /epoxKWwvZRw9w7pJXOw== Precedence: bulk List-ID: X-Mailing-List: linux-pwm@vger.kernel.org The Netronix embedded controller is a microcontroller found in some e-book readers designed by the original design manufacturer Netronix, Inc. It contains RTC, battery monitoring, system power management, and PWM functionality. This driver implements register access and version detection. Third-party hardware documentation is available at: https://github.com/neuschaefer/linux/wiki/Netronix-MSP430-embedded-contr= oller The EC supports interrupts, but the driver doesn't make use of them so far. Signed-off-by: Jonathan Neusch=C3=A4fer Acked-for-MFD-by: Lee Jones =2D-- v7: - Add #define for version number (suggested by Lee Jones). v6: - https://lore.kernel.org/lkml/20201208011000.3060239-4-j.neuschaefer@gmx.= net/ - Add Lee Jones' ACK v5: - no changes v4: - https://lore.kernel.org/lkml/20201122222739.1455132-4-j.neuschaefer@gmx.= net/ - include asm/unaligned.h after linux/* - Use put_unaligned_be16 instead of open-coded big-endian packing - Clarify that 0x90=3D0xff00 causes an error in downstream kernel too - Add commas after non-sentinel positions - ntxec.h: declare structs device and regmap - Replace WARN_ON usage and add comments to explain errors - Replace dev_alert with dev_warn when the result isn't handled - Change subdevice registration error message to dev_err - Declare ntxec_reg8 as returning __be16 - Restructure version detection code - Spell out ODM v3: - https://lore.kernel.org/lkml/20200924192455.2484005-4-j.neuschaefer@gmx.= net/ - Add (EC) to CONFIG_MFD_NTXEC prompt - Relicense as GPLv2 or later - Add email address to copyright line - remove empty lines in ntxec_poweroff and ntxec_restart functions - Split long lines - Remove 'Install ... handler' comments - Make naming of struct i2c_client parameter consistent - Remove struct ntxec_info - Rework 'depends on' lines in Kconfig, hard-depend on I2C, select REGMAP_= I2C and MFD_CORE - Register subdevices via mfd_cells - Move 8-bit register conversion to ntxec.h v2: - https://lore.kernel.org/lkml/20200905133230.1014581-4-j.neuschaefer@gmx.= net/ - Add a description of the device to the patch text - Unify spelling as 'Netronix embedded controller'. 'Netronix' is the proper name of the manufacturer, but 'embedded control= ler' is just a label that I have assigned to the device. - Switch to regmap, avoid regmap use in poweroff and reboot handlers. Inspired by cf84dc0bb40f4 ("mfd: rn5t618: Make restart handler atomic sa= fe") - Use a list of known-working firmware versions instead of checking for a known-incompatible version - Prefix registers with NTXEC_REG_ - Define register values as constants - Various style cleanups as suggested by Lee Jones - Don't align =3D signs in struct initializers [Uwe Kleine-K=C3=B6nig] - Don't use dev_dbg for an error message - Explain sleep in poweroff handler - Remove (struct ntxec).client - Switch to .probe_new in i2c driver - Add .remove callback - Make CONFIG_MFD_NTXEC a tristate option =2D-- drivers/mfd/Kconfig | 11 ++ drivers/mfd/Makefile | 1 + drivers/mfd/ntxec.c | 216 ++++++++++++++++++++++++++++++++++++++ include/linux/mfd/ntxec.h | 37 +++++++ 4 files changed, 265 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 bdfce7b156216..4280bcd47ec7d 100644 =2D-- a/drivers/mfd/Kconfig +++ b/drivers/mfd/Kconfig @@ -976,6 +976,17 @@ 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 + tristate "Netronix embedded controller (EC)" + depends on OF || COMPILE_TEST + depends on I2C + select REGMAP_I2C + select MFD_CORE + help + Say yes here if you want to support the embedded controller found in + certain e-book readers designed by the original design manufacturer + Netronix. + 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 14fdb188af022..948a3bf8e3e57 100644 =2D-- a/drivers/mfd/Makefile +++ b/drivers/mfd/Makefile @@ -219,6 +219,7 @@ obj-$(CONFIG_MFD_INTEL_PMC_BXT) +=3D intel_pmc_bxt.o obj-$(CONFIG_MFD_INTEL_PMT) +=3D intel_pmt.o obj-$(CONFIG_MFD_PALMAS) +=3D palmas.o obj-$(CONFIG_MFD_VIPERBOARD) +=3D viperboard.o +obj-$(CONFIG_MFD_NTXEC) +=3D ntxec.o obj-$(CONFIG_MFD_RC5T583) +=3D rc5t583.o rc5t583-irq.o obj-$(CONFIG_MFD_RK808) +=3D rk808.o obj-$(CONFIG_MFD_RN5T618) +=3D rn5t618.o diff --git a/drivers/mfd/ntxec.c b/drivers/mfd/ntxec.c new file mode 100644 index 0000000000000..22ed2ef0669cb =2D-- /dev/null +++ b/drivers/mfd/ntxec.c @@ -0,0 +1,216 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * The Netronix embedded controller is a microcontroller found in some + * e-book readers designed by the original design manufacturer Netronix, = Inc. + * It contains RTC, battery monitoring, system power management, and PWM + * functionality. + * + * This driver implements register access, version detection, and system + * power-off/reset. + * + * Copyright 2020 Jonathan Neusch=C3=A4fer + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define NTXEC_REG_VERSION 0x00 +#define NTXEC_REG_POWEROFF 0x50 +#define NTXEC_REG_POWERKEEP 0x70 +#define NTXEC_REG_RESET 0x90 + +#define NTXEC_POWEROFF_VALUE 0x0100 +#define NTXEC_POWERKEEP_VALUE 0x0800 +#define NTXEC_RESET_VALUE 0xff00 + +static struct i2c_client *poweroff_restart_client; + +static void ntxec_poweroff(void) +{ + int res; + u8 buf[3] =3D { NTXEC_REG_POWEROFF }; + struct i2c_msg msgs[] =3D { + { + .addr =3D poweroff_restart_client->addr, + .flags =3D 0, + .len =3D sizeof(buf), + .buf =3D buf, + }, + }; + + put_unaligned_be16(NTXEC_POWEROFF_VALUE, buf + 1); + + res =3D i2c_transfer(poweroff_restart_client->adapter, msgs, ARRAY_SIZE(= msgs)); + if (res < 0) + dev_warn(&poweroff_restart_client->dev, + "Failed to power off (err =3D %d)\n", res); + + /* + * The time from the register write until the host CPU is powered off + * has been observed to be about 2.5 to 3 seconds. Sleep long enough to + * safely avoid returning from the poweroff handler. + */ + msleep(5000); +} + +static int ntxec_restart(struct notifier_block *nb, + unsigned long action, void *data) +{ + int res; + u8 buf[3] =3D { NTXEC_REG_RESET }; + /* + * NOTE: The lower half of the reset value is not sent, because sending + * it causes an I2C error. (The reset handler in the downstream driver + * does send the full two-byte value, but doesn't check the result). + */ + struct i2c_msg msgs[] =3D { + { + .addr =3D poweroff_restart_client->addr, + .flags =3D 0, + .len =3D sizeof(buf) - 1, + .buf =3D buf, + }, + }; + + put_unaligned_be16(NTXEC_RESET_VALUE, buf + 1); + + res =3D i2c_transfer(poweroff_restart_client->adapter, msgs, ARRAY_SIZE(= msgs)); + if (res < 0) + dev_warn(&poweroff_restart_client->dev, + "Failed to restart (err =3D %d)\n", res); + + return NOTIFY_DONE; +} + +static struct notifier_block ntxec_restart_handler =3D { + .notifier_call =3D ntxec_restart, + .priority =3D 128, +}; + +static const struct regmap_config regmap_config =3D { + .name =3D "ntxec", + .reg_bits =3D 8, + .val_bits =3D 16, + .cache_type =3D REGCACHE_NONE, + .val_format_endian =3D REGMAP_ENDIAN_BIG, +}; + +static const struct mfd_cell ntxec_subdevices[] =3D { + { .name =3D "ntxec-rtc" }, + { .name =3D "ntxec-pwm" }, +}; + +static int ntxec_probe(struct i2c_client *client) +{ + struct ntxec *ec; + unsigned int version; + int res; + + ec =3D devm_kmalloc(&client->dev, sizeof(*ec), GFP_KERNEL); + if (!ec) + return -ENOMEM; + + ec->dev =3D &client->dev; + + ec->regmap =3D devm_regmap_init_i2c(client, ®map_config); + if (IS_ERR(ec->regmap)) { + dev_err(ec->dev, "Failed to set up regmap for device\n"); + return res; + } + + /* Determine the firmware version */ + res =3D regmap_read(ec->regmap, NTXEC_REG_VERSION, &version); + if (res < 0) { + dev_err(ec->dev, "Failed to read firmware version number\n"); + return res; + } + + /* Bail out if we encounter an unknown firmware version */ + switch (version) { + case NTXEC_VERSION_KOBO_AURA: + break; + default: + dev_err(ec->dev, + "Netronix embedded controller version %04x is not supported.\n", + version); + return -ENODEV; + } + + dev_info(ec->dev, + "Netronix embedded controller version %04x detected.\n", version); + + 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 =3D regmap_write(ec->regmap, NTXEC_REG_POWERKEEP, + NTXEC_POWERKEEP_VALUE); + if (res < 0) + return res; + + if (poweroff_restart_client) + /* + * Another instance of the driver already took + * poweroff/restart duties. + */ + dev_err(ec->dev, "poweroff_restart_client already assigned\n"); + else + poweroff_restart_client =3D client; + + if (pm_power_off) + /* Another driver already registered a poweroff handler. */ + dev_err(ec->dev, "pm_power_off already assigned\n"); + else + pm_power_off =3D ntxec_poweroff; + + res =3D register_restart_handler(&ntxec_restart_handler); + if (res) + dev_err(ec->dev, + "Failed to register restart handler: %d\n", res); + } + + i2c_set_clientdata(client, ec); + + res =3D devm_mfd_add_devices(ec->dev, PLATFORM_DEVID_NONE, ntxec_subdevi= ces, + ARRAY_SIZE(ntxec_subdevices), NULL, 0, NULL); + if (res) + dev_err(ec->dev, "Failed to add subdevices: %d\n", res); + + return res; +} + +static int ntxec_remove(struct i2c_client *client) +{ + if (client =3D=3D poweroff_restart_client) { + poweroff_restart_client =3D NULL; + pm_power_off =3D NULL; + unregister_restart_handler(&ntxec_restart_handler); + } + + return 0; +} + +static const struct of_device_id of_ntxec_match_table[] =3D { + { .compatible =3D "netronix,ntxec", }, + {} +}; + +static struct i2c_driver ntxec_driver =3D { + .driver =3D { + .name =3D "ntxec", + .of_match_table =3D of_ntxec_match_table, + }, + .probe_new =3D ntxec_probe, + .remove =3D ntxec_remove, +}; +module_i2c_driver(ntxec_driver); diff --git a/include/linux/mfd/ntxec.h b/include/linux/mfd/ntxec.h new file mode 100644 index 0000000000000..361204d125f1a =2D-- /dev/null +++ b/include/linux/mfd/ntxec.h @@ -0,0 +1,37 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright 2020 Jonathan Neusch=C3=A4fer + * + * Register access and version information for the Netronix embedded + * controller. + */ + +#ifndef NTXEC_H +#define NTXEC_H + +#include + +struct device; +struct regmap; + +struct ntxec { + struct device *dev; + struct regmap *regmap; +}; + +/* + * Some registers, such as the battery status register (0x41), are in + * big-endian, but others only have eight significant bits, which are in = the + * first byte transmitted over I2C (the MSB of the big-endian value). + * This convenience function converts an 8-bit value to 16-bit for use in= the + * second kind of register. + */ +static inline __be16 ntxec_reg8(u8 value) +{ + return value << 8; +} + +/* Known firmware versions */ +#define NTXEC_VERSION_KOBO_AURA 0xd726 /* found in Kobo Aura */ + +#endif =2D- 2.29.2