Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752961AbbKZAID (ORCPT ); Wed, 25 Nov 2015 19:08:03 -0500 Received: from us-mx2.synaptics.com ([192.147.44.131]:52851 "EHLO us-mx1.synaptics.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752787AbbKZAHx (ORCPT ); Wed, 25 Nov 2015 19:07:53 -0500 From: Andrew Duggan To: , CC: Andrew Duggan , Dmitry Torokhov , Linus Walleij , Benjamin Tissoires , Christopher Heiny , Stephen Chandler Paul , Vincent Huang Subject: [PATCH 02/10] Input: synaptics-rmi4: Add I2C transport driver Date: Wed, 25 Nov 2015 16:07:20 -0800 Message-ID: <1448496448-25123-3-git-send-email-aduggan@synaptics.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1448496448-25123-1-git-send-email-aduggan@synaptics.com> References: <1448496448-25123-1-git-send-email-aduggan@synaptics.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.4.10.145] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8486 Lines: 316 Add the transport driver for devices using RMI4 over I2C. Signed-off-by: Andrew Duggan Signed-off-by: Christopher Heiny --- drivers/input/rmi4/Kconfig | 11 ++ drivers/input/rmi4/Makefile | 3 + drivers/input/rmi4/rmi_i2c.c | 260 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 274 insertions(+) create mode 100644 drivers/input/rmi4/rmi_i2c.c diff --git a/drivers/input/rmi4/Kconfig b/drivers/input/rmi4/Kconfig index 45a9ff4..e1c07fc 100644 --- a/drivers/input/rmi4/Kconfig +++ b/drivers/input/rmi4/Kconfig @@ -24,3 +24,14 @@ config RMI4_DEBUG if you are actively developing/debugging RMI4 features. If unsure, say N. + +config RMI4_I2C + tristate "RMI4 I2C Support" + depends on RMI4_CORE && I2C + help + Say Y here if you want to support RMI4 devices connected to an I2C + bus. + + If unsure, say Y. + + This feature is not currently available as a loadable module. diff --git a/drivers/input/rmi4/Makefile b/drivers/input/rmi4/Makefile index b33768f..0bb318d 100644 --- a/drivers/input/rmi4/Makefile +++ b/drivers/input/rmi4/Makefile @@ -1,4 +1,7 @@ obj-$(CONFIG_RMI4_CORE) += rmi_core.o rmi_core-y := rmi_bus.o rmi_driver.o rmi_f01.o +# Transports +obj-$(CONFIG_RMI4_I2C) += rmi_i2c.o + ccflags-$(CONFIG_RMI4_DEBUG) += -DDEBUG diff --git a/drivers/input/rmi4/rmi_i2c.c b/drivers/input/rmi4/rmi_i2c.c new file mode 100644 index 0000000..c6e680d --- /dev/null +++ b/drivers/input/rmi4/rmi_i2c.c @@ -0,0 +1,260 @@ +/* + * Copyright (c) 2011-2015 Synaptics Incorporated + * Copyright (c) 2011 Unixphere + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + */ + +#include +#include +#include "rmi_driver.h" + +#define BUFFER_SIZE_INCREMENT 32 + +/** + * struct rmi_i2c_xport - stores information for i2c communication + * + * @xport: The transport interface structure + * + * @page_mutex: Locks current page to avoid changing pages in unexpected ways. + * @page: Keeps track of the current virtual page + * + * @tx_buf: Buffer used for transmitting data to the sensor over i2c. + * @tx_buf_size: Size of the buffer + */ +struct rmi_i2c_xport { + struct rmi_transport_dev xport; + struct i2c_client *client; + + struct mutex page_mutex; + int page; + + u8 *tx_buf; + size_t tx_buf_size; +}; + +#define RMI_PAGE_SELECT_REGISTER 0xff +#define RMI_I2C_PAGE(addr) (((addr) >> 8) & 0xff) + +/* + * rmi_set_page - Set RMI page + * @xport: The pointer to the rmi_transport_dev struct + * @page: The new page address. + * + * RMI devices have 16-bit addressing, but some of the transport + * implementations (like SMBus) only have 8-bit addressing. So RMI implements + * a page address at 0xff of every page so we can reliable page addresses + * every 256 registers. + * + * The page_mutex lock must be held when this function is entered. + * + * Returns zero on success, non-zero on failure. + */ +static int rmi_set_page(struct rmi_i2c_xport *rmi_i2c, u8 page) +{ + struct i2c_client *client = rmi_i2c->client; + u8 txbuf[2] = {RMI_PAGE_SELECT_REGISTER, page}; + int retval; + + retval = i2c_master_send(client, txbuf, sizeof(txbuf)); + if (retval != sizeof(txbuf)) { + dev_err(&client->dev, + "%s: set page failed: %d.", __func__, retval); + return (retval < 0) ? retval : -EIO; + } + + rmi_i2c->page = page; + return 0; +} + +static int rmi_i2c_write_block(struct rmi_transport_dev *xport, u16 addr, + const void *buf, size_t len) +{ + struct rmi_i2c_xport *rmi_i2c = + container_of(xport, struct rmi_i2c_xport, xport); + struct i2c_client *client = rmi_i2c->client; + size_t tx_size = len + 1; + int retval; + + mutex_lock(&rmi_i2c->page_mutex); + + if (!rmi_i2c->tx_buf || rmi_i2c->tx_buf_size < tx_size) { + if (rmi_i2c->tx_buf) + devm_kfree(&client->dev, rmi_i2c->tx_buf); + rmi_i2c->tx_buf_size = tx_size + BUFFER_SIZE_INCREMENT; + rmi_i2c->tx_buf = devm_kzalloc(&client->dev, + rmi_i2c->tx_buf_size, + GFP_KERNEL); + if (!rmi_i2c->tx_buf) { + rmi_i2c->tx_buf_size = 0; + retval = -ENOMEM; + goto exit; + } + } + + rmi_i2c->tx_buf[0] = addr & 0xff; + memcpy(rmi_i2c->tx_buf + 1, buf, len); + + if (RMI_I2C_PAGE(addr) != rmi_i2c->page) { + retval = rmi_set_page(rmi_i2c, RMI_I2C_PAGE(addr)); + if (retval) + goto exit; + } + + retval = i2c_master_send(client, rmi_i2c->tx_buf, tx_size); + if (retval == tx_size) + retval = 0; + else if (retval >= 0) + retval = -EIO; + +exit: + dev_dbg(&client->dev, + "write %zd bytes at %#06x: %d (%*ph)\n", + len, addr, retval, (int)len, buf); + + mutex_unlock(&rmi_i2c->page_mutex); + return retval; +} + +static int rmi_i2c_read_block(struct rmi_transport_dev *xport, u16 addr, + void *buf, size_t len) +{ + struct rmi_i2c_xport *rmi_i2c = + container_of(xport, struct rmi_i2c_xport, xport); + struct i2c_client *client = rmi_i2c->client; + u8 addr_offset = addr & 0xff; + int retval; + struct i2c_msg msgs[] = { + { + .addr = client->addr, + .len = sizeof(addr_offset), + .buf = &addr_offset, + }, + { + .addr = client->addr, + .flags = I2C_M_RD, + .len = len, + .buf = buf, + }, + }; + + mutex_lock(&rmi_i2c->page_mutex); + + if (RMI_I2C_PAGE(addr) != rmi_i2c->page) { + retval = rmi_set_page(rmi_i2c, RMI_I2C_PAGE(addr)); + if (retval) + goto exit; + } + + retval = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); + if (retval == ARRAY_SIZE(msgs)) + retval = 0; /* success */ + else if (retval >= 0) + retval = -EIO; + +exit: + dev_dbg(&client->dev, + "read %zd bytes at %#06x: %d (%*ph)\n", + len, addr, retval, (int)len, buf); + + mutex_unlock(&rmi_i2c->page_mutex); + return retval; +} + +static const struct rmi_transport_ops rmi_i2c_ops = { + .write_block = rmi_i2c_write_block, + .read_block = rmi_i2c_read_block, +}; + +static int rmi_i2c_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct rmi_device_platform_data *pdata; + struct rmi_device_platform_data *client_pdata = + dev_get_platdata(&client->dev); + struct rmi_i2c_xport *rmi_i2c; + int retval; + + rmi_i2c = devm_kzalloc(&client->dev, sizeof(struct rmi_i2c_xport), + GFP_KERNEL); + if (!rmi_i2c) + return -ENOMEM; + + pdata = &rmi_i2c->xport.pdata; + + if (client_pdata) + *pdata = *client_pdata; + + dev_dbg(&client->dev, "Probing %s.\n", dev_name(&client->dev)); + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { + dev_err(&client->dev, + "adapter does not support required functionality.\n"); + return -ENODEV; + } + + rmi_i2c->client = client; + mutex_init(&rmi_i2c->page_mutex); + + rmi_i2c->xport.dev = &client->dev; + rmi_i2c->xport.proto_name = "i2c"; + rmi_i2c->xport.ops = &rmi_i2c_ops; + rmi_i2c->xport.irq = client->irq; + rmi_i2c->xport.irq_flags = pdata->irq_flags; + + /* + * Setting the page to zero will (a) make sure the PSR is in a + * known state, and (b) make sure we can talk to the device. + */ + retval = rmi_set_page(rmi_i2c, 0); + if (retval) { + dev_err(&client->dev, "Failed to set page select to 0.\n"); + return retval; + } + + retval = rmi_register_transport_device(&rmi_i2c->xport); + if (retval) { + dev_err(&client->dev, "Failed to register transport driver at 0x%.2X.\n", + client->addr); + return retval; + } + + i2c_set_clientdata(client, rmi_i2c); + + dev_info(&client->dev, "registered rmi i2c driver at %#04x.\n", + client->addr); + return 0; +} + +static int rmi_i2c_remove(struct i2c_client *client) +{ + struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client); + + rmi_unregister_transport_device(&rmi_i2c->xport); + + return 0; +} + +static const struct i2c_device_id rmi_id[] = { + { "rmi_i2c", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, rmi_id); + +static struct i2c_driver rmi_i2c_driver = { + .driver = { + .owner = THIS_MODULE, + .name = "rmi_i2c", + }, + .id_table = rmi_id, + .probe = rmi_i2c_probe, + .remove = rmi_i2c_remove, +}; + +module_i2c_driver(rmi_i2c_driver); + +MODULE_AUTHOR("Christopher Heiny "); +MODULE_DESCRIPTION("RMI I2C driver"); +MODULE_LICENSE("GPL"); +MODULE_VERSION(RMI_DRIVER_VERSION); -- 2.5.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/