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bh=eMQQPwPH6zBMKiAkGJns9PNN/bsW4dSvESSYPM21Euw=; b=E9ZkxZeD4hLfdzP0mF4PvBDAIprw13kqLPvIWlJ2I2jyDDmGLpe4wYdJSAoPy+g1VHh2GK 04vLE2cKhuB3y6Jqusp2/TCxdWsu7URh4leGwAG51CUHs8K5j7YxOMIzLH0Zo8XrpasxHE cH/LHLAfvd2L5jBpIpNBAer/nRjfhkA= From: Michael Walle To: linux-gpio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hwmon@vger.kernel.org, linux-pwm@vger.kernel.org, linux-watchdog@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH v6 01/13] mfd: add simple regmap based I2C driver Date: Sun, 26 Jul 2020 01:18:22 +0200 Message-Id: <20200725231834.25642-2-michael@walle.cc> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200725231834.25642-1-michael@walle.cc> References: <20200725231834.25642-1-michael@walle.cc> MIME-Version: 1.0 X-Spam: Yes X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200725_191907_391921_C482B73A X-CRM114-Status: GOOD ( 23.13 ) X-Spam-Score: -2.5 (--) X-Spam-Report: SpamAssassin version 3.4.4 on merlin.infradead.org summary: Content analysis details: (-2.5 points) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at https://www.dnswl.org/, medium trust [176.9.125.105 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Marc Zyngier , Jean Delvare , Catalin Marinas , Jason Cooper , Will Deacon , Greg Kroah-Hartman , Shawn Guo , Linus Walleij , Andy Shevchenko , Li Yang , Bartosz Golaszewski , Michael Walle , Rob Herring , Thierry Reding , Mark Brown , Pavel Machek , =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= , Thomas Gleixner , Wim Van Sebroeck , Lee Jones , Guenter Roeck Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org There are I2C devices which contain several different functions but doesn't require any special access functions. For these kind of drivers an I2C regmap should be enough. Create an I2C driver which creates an I2C regmap and enumerates its children. If a device wants to use this as its MFD core driver, it has to add an individual compatible string. It may provide its own regmap configuration. Subdevices can use dev_get_regmap() on the parent to get their regmap instance. Signed-off-by: Michael Walle --- Changes since v5: - removed "select MFD_CORE" in Kconfig - removed help text in Kconfig, we assume that the users of this driver will have a "select MFD_SIMPLE_MFD_I2C". Instead added a small description to the driver itself. - removed "struct simple_mfd_i2c_config" and use regmap_config directly - changed builtin_i2c_driver() to module_i2c_driver(), added MODULE_ boilerplate - cleaned up the included files Changes since v4: - new patch. Lee, please bear with me. I didn't want to delay the new version (where a lot of remarks on the other patches were addressed) even more, just because we haven't figured out how to deal with the MFD part. So for now, I've included this one. drivers/mfd/Kconfig | 5 ++++ drivers/mfd/Makefile | 1 + drivers/mfd/simple-mfd-i2c.c | 55 ++++++++++++++++++++++++++++++++++++ 3 files changed, 61 insertions(+) create mode 100644 drivers/mfd/simple-mfd-i2c.c diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig index 33df0837ab41..c08539c7a166 100644 --- a/drivers/mfd/Kconfig +++ b/drivers/mfd/Kconfig @@ -1162,6 +1162,11 @@ config MFD_SI476X_CORE To compile this driver as a module, choose M here: the module will be called si476x-core. +config MFD_SIMPLE_MFD_I2C + tristate + depends on I2C + select REGMAP_I2C + config MFD_SM501 tristate "Silicon Motion SM501" depends on HAS_DMA diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile index a60e5f835283..78d24a3e7c9e 100644 --- a/drivers/mfd/Makefile +++ b/drivers/mfd/Makefile @@ -264,3 +264,4 @@ obj-$(CONFIG_MFD_STMFX) += stmfx.o obj-$(CONFIG_MFD_KHADAS_MCU) += khadas-mcu.o obj-$(CONFIG_SGI_MFD_IOC3) += ioc3.o +obj-$(CONFIG_MFD_SIMPLE_MFD_I2C) += simple-mfd-i2c.o diff --git a/drivers/mfd/simple-mfd-i2c.c b/drivers/mfd/simple-mfd-i2c.c new file mode 100644 index 000000000000..45090ddad104 --- /dev/null +++ b/drivers/mfd/simple-mfd-i2c.c @@ -0,0 +1,55 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * A very simple I2C MFD driver + * + * The driver enumerates its children and registers a common regmap. Use + * dev_get_regmap(pdev->dev.parent, NULL) in the child nodes to fetch that + * regmap instance. + * + * In the future this driver might be extended to support also other interfaces + * like SPI etc. + */ +#include +#include +#include +#include +#include + +static const struct regmap_config simple_regmap_config = { + .reg_bits = 8, + .val_bits = 8, +}; + +static int simple_mfd_i2c_probe(struct i2c_client *i2c) +{ + const struct regmap_config *config; + struct regmap *regmap; + + config = device_get_match_data(&i2c->dev); + if (!config) + config = &simple_regmap_config; + + regmap = devm_regmap_init_i2c(i2c, config); + if (IS_ERR(regmap)) + return PTR_ERR(regmap); + + return devm_of_platform_populate(&i2c->dev); +} + +static const struct of_device_id simple_mfd_i2c_of_match[] = { + {} +}; +MODULE_DEVICE_TABLE(of, simple_mfd_i2c_of_match); + +static struct i2c_driver simple_mfd_i2c_driver = { + .probe_new = simple_mfd_i2c_probe, + .driver = { + .name = "simple-mfd-i2c", + .of_match_table = simple_mfd_i2c_of_match, + }, +}; +module_i2c_driver(simple_mfd_i2c_driver); + +MODULE_AUTHOR("Michael Walle "); +MODULE_DESCRIPTION("Simple I2C MFD driver"); +MODULE_LICENSE("GPL v2");