From patchwork Tue Sep 9 14:54:28 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wolfram Sang X-Patchwork-Id: 4870971 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 0E56FC0338 for ; Tue, 9 Sep 2014 14:57:38 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id AD53B2017A for ; Tue, 9 Sep 2014 14:57:36 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D1E6120149 for ; Tue, 9 Sep 2014 14:57:34 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1XRMpJ-0000oi-GT; Tue, 09 Sep 2014 14:55:25 +0000 Received: from sauhun.de ([89.238.76.85] helo=pokefinder.org) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XRMoj-0007ls-On for linux-arm-kernel@lists.infradead.org; Tue, 09 Sep 2014 14:54:52 +0000 Received: from p4fe24daa.dip0.t-ipconnect.de ([79.226.77.170]:40151 helo=localhost) by pokefinder.org with esmtpsa (TLS1.2:RSA_AES_128_CBC_SHA1:128) (Exim 4.80) (envelope-from ) id 1XRMoJ-0000p8-7t; Tue, 09 Sep 2014 16:54:23 +0200 From: Wolfram Sang To: linux-i2c@vger.kernel.org Subject: [RFC 2/4] i2c: slave: add eeprom simulator driver Date: Tue, 9 Sep 2014 16:54:28 +0200 Message-Id: <1410274470-12712-3-git-send-email-wsa@the-dreams.de> X-Mailer: git-send-email 2.0.0 In-Reply-To: <1410274470-12712-1-git-send-email-wsa@the-dreams.de> References: <1410274470-12712-1-git-send-email-wsa@the-dreams.de> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140909_075450_044996_7276194F X-CRM114-Status: GOOD ( 15.34 ) X-Spam-Score: -0.0 (/) Cc: Jean Delvare , Magnus Damm , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sh@vger.kernel.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Wolfram Sang Signed-off-by: Wolfram Sang --- drivers/i2c/Kconfig | 10 +++ drivers/i2c/Makefile | 1 + drivers/i2c/i2c-slave-eeprom.c | 152 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 163 insertions(+) create mode 100644 drivers/i2c/i2c-slave-eeprom.c diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig index b51a402752c4..f7800104b2ff 100644 --- a/drivers/i2c/Kconfig +++ b/drivers/i2c/Kconfig @@ -110,6 +110,16 @@ config I2C_STUB If you don't know what to do here, definitely say N. +config I2C_SLAVE + bool "I2C slave support" + +if I2C_SLAVE + +config I2C_SLAVE_EEPROM + bool "I2C eeprom slave driver" + +endif + config I2C_DEBUG_CORE bool "I2C Core debugging messages" help diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile index e0228b228256..d78f81caad8a 100644 --- a/drivers/i2c/Makefile +++ b/drivers/i2c/Makefile @@ -12,6 +12,7 @@ obj-$(CONFIG_I2C_CHARDEV) += i2c-dev.o obj-$(CONFIG_I2C_MUX) += i2c-mux.o obj-y += algos/ busses/ muxes/ obj-$(CONFIG_I2C_STUB) += i2c-stub.o +obj-$(CONFIG_I2C_SLAVE_EEPROM) += i2c-slave-eeprom.o ccflags-$(CONFIG_I2C_DEBUG_CORE) := -DDEBUG CFLAGS_i2c-core.o := -Wno-deprecated-declarations diff --git a/drivers/i2c/i2c-slave-eeprom.c b/drivers/i2c/i2c-slave-eeprom.c new file mode 100644 index 000000000000..e512a40a3c36 --- /dev/null +++ b/drivers/i2c/i2c-slave-eeprom.c @@ -0,0 +1,152 @@ +/* + * I2C Slave mode EEPROM simulator + * + * Copyright (C) 2014 by Wolfram Sang, Sang Engineering + * Copyright (C) 2014 by Renesas Solutions Corp. + * + * 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; version 2 of the License. + */ + +#include +#include +#include +#include +#include +#include + +//TODO: simulate 24c32 as well +#define EEPROM_SIZE 256 + +struct at24s_data { + //TODO: use lock + struct mutex lock; + struct bin_attribute bin; + u8 buffer[EEPROM_SIZE]; + u8 eeprom_ptr; + bool first_write; +}; + +static int at24s_slave_cb(struct i2c_client *client, enum i2c_slave_event event, u8 *val) +{ + struct at24s_data *at24s = i2c_get_clientdata(client); + + switch (event) { + case I2C_SLAVE_REQ_WRITE_END: + if (at24s->first_write) { + at24s->eeprom_ptr = *val; + at24s->first_write = false; + } else { + at24s->buffer[at24s->eeprom_ptr++] = *val; + } + break; + + case I2C_SLAVE_REQ_READ_START: + *val = at24s->buffer[at24s->eeprom_ptr]; + break; + + case I2C_SLAVE_REQ_READ_END: + at24s->eeprom_ptr++; + break; + + case I2C_SLAVE_STOP: + at24s->first_write = true; + break; + + default: + break; + } + + return 0; +} + +static ssize_t at24s_bin_read(struct file *filp, struct kobject *kobj, + struct bin_attribute *attr, char *buf, loff_t off, size_t count) +{ + struct at24s_data *at24s; + + at24s = dev_get_drvdata(container_of(kobj, struct device, kobj)); + + //TODO: boundary checks + memcpy(buf, &at24s->buffer[off], count); + + return count; +} + +static ssize_t at24s_bin_write(struct file *filp, struct kobject *kobj, + struct bin_attribute *attr, char *buf, loff_t off, size_t count) +{ + struct at24s_data *at24s; + + if (unlikely(off >= attr->size)) + return -EFBIG; + + at24s = dev_get_drvdata(container_of(kobj, struct device, kobj)); + + //TODO: boundary checks + memcpy(&at24s->buffer[off], buf, count); + + return count; +} + +static int i2c_slave_eeprom_probe(struct i2c_client *client, const struct i2c_device_id *id) +{ + struct at24s_data *at24s; + int ret; + + at24s = devm_kzalloc(&client->dev, sizeof(struct at24s_data), GFP_KERNEL); + if (!at24s) + return -ENOMEM; + + at24s->first_write = true; + i2c_set_clientdata(client, at24s); + + ret = i2c_slave_register(client, at24s_slave_cb); + if (ret) + return ret; + + sysfs_bin_attr_init(&at24s->bin); + at24s->bin.attr.name = "slave-eeprom"; + at24s->bin.attr.mode = S_IRUSR | S_IWUSR; + at24s->bin.read = at24s_bin_read; + at24s->bin.write = at24s_bin_write; + at24s->bin.size = EEPROM_SIZE; + + ret = sysfs_create_bin_file(&client->dev.kobj, &at24s->bin); + if (ret) + return ret; + + return 0; +}; + +static int i2c_slave_eeprom_remove(struct i2c_client *client) +{ + struct at24s_data *at24s; + + at24s = i2c_get_clientdata(client); + sysfs_remove_bin_file(&client->dev.kobj, &at24s->bin); + + return i2c_slave_unregister(client); +} + +static const struct i2c_device_id i2c_slave_eeprom_id[] = { + { "slave-24c02", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, i2c_slave_eeprom_id); + +static struct i2c_driver i2c_slave_eeprom_driver = { + .driver = { + .name = "i2c-slave-eeprom", + .owner = THIS_MODULE, + }, + .probe = i2c_slave_eeprom_probe, + .remove = i2c_slave_eeprom_remove, + .id_table = i2c_slave_eeprom_id, +}; +module_i2c_driver(i2c_slave_eeprom_driver); + +MODULE_AUTHOR("Wolfram Sang "); +MODULE_DESCRIPTION("I2C slave mode EEPROM simulator"); +MODULE_LICENSE("GPL v2");