From patchwork Mon Mar 13 11:33:08 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Francesco Dolcini X-Patchwork-Id: 662843 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B3430C6FD19 for ; Mon, 13 Mar 2023 11:34:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229987AbjCMLe2 (ORCPT ); Mon, 13 Mar 2023 07:34:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36632 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229704AbjCMLe1 (ORCPT ); Mon, 13 Mar 2023 07:34:27 -0400 Received: from mail11.truemail.it (mail11.truemail.it [217.194.8.81]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4E54E1A493; Mon, 13 Mar 2023 04:34:01 -0700 (PDT) Received: from francesco-nb.pivistrello.it (93-49-2-63.ip317.fastwebnet.it [93.49.2.63]) by mail11.truemail.it (Postfix) with ESMTPA id 4A36221DF3; Mon, 13 Mar 2023 12:33:15 +0100 (CET) From: Francesco Dolcini To: linux-gpio@vger.kernel.org, Linus Walleij , Bartosz Golaszewski Cc: Emanuele Ghidoli , linux-kernel@vger.kernel.org, andy.shevchenko@gmail.com, Francesco Dolcini Subject: [PATCH v2 2/2] gpio: fxl6408: add I2C GPIO expander driver Date: Mon, 13 Mar 2023 12:33:08 +0100 Message-Id: <20230313113308.157930-3-francesco@dolcini.it> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230313113308.157930-1-francesco@dolcini.it> References: <20230313113308.157930-1-francesco@dolcini.it> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org From: Emanuele Ghidoli Add minimal driver for Fairchild FXL6408 8-bit I2C-controlled GPIO expander using the generic regmap based GPIO driver (GPIO_REGMAP). The driver implements setting the GPIO direction, reading inputs and writing outputs. In addition to that the FXL6408 has the following functionalities: - allows to monitor input ports for data transitions with an interrupt pin - all inputs can be configured with pull-up or pull-down resistors Datasheet: https://www.onsemi.com/download/data-sheet/pdf/fxl6408-d.pdf Signed-off-by: Emanuele Ghidoli Signed-off-by: Francesco Dolcini --- v2: * remove includes: and * add missing and required select REGMAP_I2C in KConfig * use dev_err_probe() * add "Datasheet:" tag in commit message * improve KConfig help section * fix newlines, multi-line comments and trailing commas --- drivers/gpio/Kconfig | 10 +++ drivers/gpio/Makefile | 1 + drivers/gpio/gpio-fxl6408.c | 152 ++++++++++++++++++++++++++++++++++++ 3 files changed, 163 insertions(+) create mode 100644 drivers/gpio/gpio-fxl6408.c diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 13be729710f2..56a73007ebcb 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -1000,6 +1000,16 @@ config GPIO_ADNP enough to represent all pins, but the driver will assume a register layout for 64 pins (8 registers). +config GPIO_FXL6408 + tristate "FXL6408 I2C GPIO expander" + select GPIO_REGMAP + select REGMAP_I2C + help + GPIO driver for Fairchild Semiconductor FXL6408 GPIO expander. + + To compile this driver as a module, choose M here: the module will + be called gpio-fxl6408. + config GPIO_GW_PLD tristate "Gateworks PLD GPIO Expander" depends on OF_GPIO diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index c048ba003367..12027f4c3bee 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -60,6 +60,7 @@ obj-$(CONFIG_GPIO_EP93XX) += gpio-ep93xx.o obj-$(CONFIG_GPIO_EXAR) += gpio-exar.o obj-$(CONFIG_GPIO_F7188X) += gpio-f7188x.o obj-$(CONFIG_GPIO_FTGPIO010) += gpio-ftgpio010.o +obj-$(CONFIG_GPIO_FXL6408) += gpio-fxl6408.o obj-$(CONFIG_GPIO_GE_FPGA) += gpio-ge.o obj-$(CONFIG_GPIO_GPIO_MM) += gpio-gpio-mm.o obj-$(CONFIG_GPIO_GRGPIO) += gpio-grgpio.o diff --git a/drivers/gpio/gpio-fxl6408.c b/drivers/gpio/gpio-fxl6408.c new file mode 100644 index 000000000000..2560fe99c2d6 --- /dev/null +++ b/drivers/gpio/gpio-fxl6408.c @@ -0,0 +1,152 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * FXL6408 GPIO driver + * + * Copyright 2023 Toradex + * + * Author: Emanuele Ghidoli + */ + +#include +#include +#include +#include + +#define FXL6408_REG_DEVICE_ID 0x01 +#define FXL6408_MF_FAIRCHILD 0b101 +#define FXL6408_MF_SHIFT 5 + +/* Bits set here indicate that the GPIO is an output. */ +#define FXL6408_REG_IO_DIR 0x03 + +/* + * Bits set here, when the corresponding bit of IO_DIR is set, drive + * the output high instead of low. + */ +#define FXL6408_REG_OUTPUT 0x05 + +/* Bits here make the output High-Z, instead of the OUTPUT value. */ +#define FXL6408_REG_OUTPUT_HIGH_Z 0x07 + +/* Returns the current status (1 = HIGH) of the input pins. */ +#define FXL6408_REG_INPUT_STATUS 0x0f + +#define FXL6408_MAX_REGISTER 0x13 + +#define FXL6408_NGPIO 8 + +static const struct regmap_range rd_range[] = { + { FXL6408_REG_DEVICE_ID, FXL6408_REG_DEVICE_ID }, + { FXL6408_REG_IO_DIR, FXL6408_REG_OUTPUT }, + { FXL6408_REG_INPUT_STATUS, FXL6408_REG_INPUT_STATUS }, +}; + +static const struct regmap_range wr_range[] = { + { FXL6408_REG_DEVICE_ID, FXL6408_REG_DEVICE_ID }, + { FXL6408_REG_IO_DIR, FXL6408_REG_OUTPUT }, + { FXL6408_REG_OUTPUT_HIGH_Z, FXL6408_REG_OUTPUT_HIGH_Z }, +}; + +static const struct regmap_range volatile_range[] = { + { FXL6408_REG_DEVICE_ID, FXL6408_REG_DEVICE_ID }, + { FXL6408_REG_INPUT_STATUS, FXL6408_REG_INPUT_STATUS }, +}; + +static const struct regmap_access_table rd_table = { + .yes_ranges = rd_range, + .n_yes_ranges = ARRAY_SIZE(rd_range), +}; + +static const struct regmap_access_table wr_table = { + .yes_ranges = wr_range, + .n_yes_ranges = ARRAY_SIZE(wr_range), +}; + +static const struct regmap_access_table volatile_table = { + .yes_ranges = volatile_range, + .n_yes_ranges = ARRAY_SIZE(volatile_range), +}; + +static const struct regmap_config regmap = { + .reg_bits = 8, + .val_bits = 8, + + .max_register = FXL6408_MAX_REGISTER, + .wr_table = &wr_table, + .rd_table = &rd_table, + .volatile_table = &volatile_table, + + .cache_type = REGCACHE_RBTREE, + .num_reg_defaults_raw = FXL6408_MAX_REGISTER + 1, +}; + +static int fxl6408_identify(struct device *dev, struct regmap *regmap) +{ + int val, ret; + + ret = regmap_read(regmap, FXL6408_REG_DEVICE_ID, &val); + if (ret) { + dev_err(dev, "error %d reading DEVICE_ID\n", ret); + } else if (val >> FXL6408_MF_SHIFT != FXL6408_MF_FAIRCHILD) { + dev_err(dev, "invalid device id 0x%02x\n", val); + ret = -ENODEV; + } + + return ret; +} + +static int fxl6408_probe(struct i2c_client *client) +{ + struct device *dev = &client->dev; + int ret; + struct gpio_regmap_config gpio_config = { + .parent = dev, + .ngpio = FXL6408_NGPIO, + .reg_dat_base = GPIO_REGMAP_ADDR(FXL6408_REG_INPUT_STATUS), + .reg_set_base = GPIO_REGMAP_ADDR(FXL6408_REG_OUTPUT), + .reg_dir_out_base = GPIO_REGMAP_ADDR(FXL6408_REG_IO_DIR), + .ngpio_per_reg = FXL6408_NGPIO, + }; + + gpio_config.regmap = devm_regmap_init_i2c(client, ®map); + if (IS_ERR(gpio_config.regmap)) + return dev_err_probe(dev, PTR_ERR(gpio_config.regmap), + "failed to allocate register map\n"); + + ret = fxl6408_identify(dev, gpio_config.regmap); + if (ret) + return ret; + + /* Disable High-Z of outputs, so that our OUTPUT updates actually take effect. */ + ret = regmap_write(gpio_config.regmap, FXL6408_REG_OUTPUT_HIGH_Z, 0); + if (ret) + return dev_err_probe(dev, ret, "failed to write 'output high Z' register\n"); + + return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(dev, &gpio_config)); +} + +static const __maybe_unused struct of_device_id fxl6408_dt_ids[] = { + { .compatible = "fcs,fxl6408" }, + { } +}; +MODULE_DEVICE_TABLE(of, fxl6408_dt_ids); + +static const struct i2c_device_id fxl6408_id[] = { + { "fxl6408", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, fxl6408_id); + +static struct i2c_driver fxl6408_driver = { + .driver = { + .name = "fxl6408", + .of_match_table = fxl6408_dt_ids, + }, + .probe_new = fxl6408_probe, + .id_table = fxl6408_id, +}; +module_i2c_driver(fxl6408_driver); + +MODULE_AUTHOR("Emanuele Ghidoli "); +MODULE_DESCRIPTION("FXL6408 GPIO driver"); +MODULE_LICENSE("GPL");