Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754070Ab2KQEAQ (ORCPT ); Fri, 16 Nov 2012 23:00:16 -0500 Received: from [12.239.217.82] ([12.239.217.82]:46114 "EHLO brontomerus.synaptics.com" rhost-flags-FAIL-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1753900Ab2KQD74 (ORCPT ); Fri, 16 Nov 2012 22:59:56 -0500 From: Christopher Heiny To: Dmitry Torokhov Cc: Jean Delvare , Linux Kernel , Linux Input , Christopher Heiny , Allie Xiong , Vivian Ly , Daniel Rosenberg , Alexandra Chin , Joerie de Gram , Wolfram Sang , Mathieu Poirier , Linus Walleij , Naveen Kumar Gaddipati Subject: [RFC PATCH 03/06] input/rmi4: I2C physical interface Date: Fri, 16 Nov 2012 19:58:51 -0800 Message-Id: <1353124734-16803-4-git-send-email-cheiny@synaptics.com> X-Mailer: git-send-email 1.7.7.6 In-Reply-To: <1353124734-16803-1-git-send-email-cheiny@synaptics.com> References: <1353124734-16803-1-git-send-email-cheiny@synaptics.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 14037 Lines: 523 rmi_i2c.c abstracts an RMI4 device on some arbitrary I2C bus as a logical device in the RMI bus. It handles reads/writes from/to the RMI4 devices, and manages the page select register setting (since the meaning of page select is dependent on the physical layer used to communicate with the RMi4 device). Signed-off-by: Christopher Heiny Cc: Dmitry Torokhov Cc: Linus Walleij Cc: Naveen Kumar Gaddipati Cc: Joeri de Gram Acked-by: Jean Delvare --- drivers/input/rmi4/rmi_i2c.c | 490 ++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 490 insertions(+), 0 deletions(-) diff --git a/drivers/input/rmi4/rmi_i2c.c b/drivers/input/rmi4/rmi_i2c.c new file mode 100644 index 0000000..ca32101 --- /dev/null +++ b/drivers/input/rmi4/rmi_i2c.c @@ -0,0 +1,490 @@ +/* + * Copyright (c) 2011, 2012 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 as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "rmi_driver.h" + +#define BUFFER_SIZE_INCREMENT 32 +/** + * struct rmi_i2c_data - stores information for i2c communication + * + * @page_mutex: Locks current page to avoid changing pages in unexpected ways. + * @page: Keeps track of the current virtual page + * @phys: Pointer to the physical interface + * + * @tx_buf: Buffer used for transmitting data to the sensor over i2c. + * @tx_buf_size: Size of the buffer + * @debug_buf: Buffer used for exposing buffer contents using dev_dbg + * @debug_buf_size: Size of the debug buffer. + * + * @comms_debug: Latest data read/written for debugging I2C communications + * @debugfs_comms: Debugfs file for debugging I2C communications + * + */ +struct rmi_i2c_data { + struct mutex page_mutex; + int page; + struct rmi_phys_device *phys; + + u8 *tx_buf; + int tx_buf_size; + u8 *debug_buf; + int debug_buf_size; + + bool comms_debug; +#ifdef CONFIG_RMI4_DEBUG + struct dentry *debugfs_comms; +#endif +}; + +#ifdef CONFIG_RMI4_DEBUG + + +/** + * struct i2c_debugfs_data - stores information for debugfs + * + * @done: Indicates that we are done reading debug data. Subsequent reads + * will return EOF. + * @i2c_data: Pointer to the i2c data + * + */ +struct i2c_debugfs_data { + bool done; + struct rmi_i2c_data *i2c_data; +}; + +static int debug_open(struct inode *inodep, struct file *filp) +{ + struct i2c_debugfs_data *data; + + data = kzalloc(sizeof(struct i2c_debugfs_data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->i2c_data = inodep->i_private; + filp->private_data = data; + return 0; +} + +static int debug_release(struct inode *inodep, struct file *filp) +{ + kfree(filp->private_data); + return 0; +} + +static ssize_t comms_debug_read(struct file *filp, char __user *buffer, + size_t size, loff_t *offset) { + int retval; + char *local_buf; + struct i2c_debugfs_data *dfs = filp->private_data; + struct rmi_i2c_data *data = dfs->i2c_data; + + if (dfs->done) + return 0; + + local_buf = kcalloc(size, sizeof(u8), GFP_KERNEL); + if (!local_buf) + return -ENOMEM; + + dfs->done = 1; + + retval = snprintf(local_buf, PAGE_SIZE, "%u\n", data->comms_debug); + + if (retval <= 0 || copy_to_user(buffer, local_buf, retval)) + retval = -EFAULT; + kfree(local_buf); + + return retval; +} + +static ssize_t comms_debug_write(struct file *filp, const char __user *buffer, + size_t size, loff_t *offset) { + int retval; + char *local_buf; + unsigned int new_value; + struct i2c_debugfs_data *dfs = filp->private_data; + struct rmi_i2c_data *data = dfs->i2c_data; + + local_buf = kcalloc(size, sizeof(u8), GFP_KERNEL); + if (!local_buf) + return -ENOMEM; + retval = copy_from_user(local_buf, buffer, size); + if (retval) { + kfree(local_buf); + return -EFAULT; + } + + retval = sscanf(local_buf, "%u", &new_value); + kfree(local_buf); + if (retval != 1 || new_value > 1) + return -EINVAL; + + data->comms_debug = new_value; + + return size; +} + + +static const struct file_operations comms_debug_fops = { + .owner = THIS_MODULE, + .open = debug_open, + .release = debug_release, + .read = comms_debug_read, + .write = comms_debug_write, +}; + +static int setup_debugfs(struct rmi_device *rmi_dev, struct rmi_i2c_data *data) +{ + if (!rmi_dev->debugfs_root) + return -ENODEV; + + data->debugfs_comms = debugfs_create_file("comms_debug", RMI_RW_ATTR, + rmi_dev->debugfs_root, data, &comms_debug_fops); + if (!data->debugfs_comms || IS_ERR(data->debugfs_comms)) { + dev_warn(&rmi_dev->dev, "Failed to create debugfs comms_debug.\n"); + data->debugfs_comms = NULL; + } + + return 0; +} + +static void teardown_debugfs(struct rmi_i2c_data *data) +{ + if (data->debugfs_comms) + debugfs_remove(data->debugfs_comms); +} +#endif + +#define COMMS_DEBUG(data) (IS_ENABLED(CONFIG_RMI4_DEBUG) && data->comms_debug) + +#define RMI_PAGE_SELECT_REGISTER 0xff +#define RMI_I2C_PAGE(addr) (((addr) >> 8) & 0xff) + +static char *phys_proto_name = "i2c"; + +/* + * rmi_set_page - Set RMI page + * @phys: The pointer to the rmi_phys_device struct + * @page: The new page address. + * + * RMI devices have 16-bit addressing, but some of the physical + * 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_phys_device *phys, u8 page) +{ + struct i2c_client *client = to_i2c_client(phys->dev); + struct rmi_i2c_data *data = phys->data; + u8 txbuf[2] = {RMI_PAGE_SELECT_REGISTER, page}; + int retval; + + if (COMMS_DEBUG(data)) + dev_dbg(&client->dev, "writes 3 bytes: %02x %02x\n", + txbuf[0], txbuf[1]); + phys->info.tx_count++; + phys->info.tx_bytes += sizeof(txbuf); + retval = i2c_master_send(client, txbuf, sizeof(txbuf)); + if (retval != sizeof(txbuf)) { + phys->info.tx_errs++; + dev_err(&client->dev, + "%s: set page failed: %d.", __func__, retval); + return (retval < 0) ? retval : -EIO; + } + data->page = page; + return 0; +} + +static int copy_to_debug_buf(struct device *dev, struct rmi_i2c_data *data, + const u8 *buf, const int len) { + int i; + int n = 0; + char *temp; + int dbg_size = 3 * len + 1; + + if (!data->debug_buf || data->debug_buf_size < dbg_size) { + if (data->debug_buf) + devm_kfree(dev, data->debug_buf); + data->debug_buf_size = dbg_size + BUFFER_SIZE_INCREMENT; + data->debug_buf = devm_kzalloc(dev, data->debug_buf_size, + GFP_KERNEL); + if (!data->debug_buf) { + data->debug_buf_size = 0; + return -ENOMEM; + } + } + temp = data->debug_buf; + + for (i = 0; i < len; i++) { + n = sprintf(temp, " %02x", buf[i]); + temp += n; + } + + return 0; +} + +static int rmi_i2c_write_block(struct rmi_phys_device *phys, u16 addr, + const void *buf, const int len) +{ + struct i2c_client *client = to_i2c_client(phys->dev); + struct rmi_i2c_data *data = phys->data; + int retval; + int tx_size = len + 1; + + mutex_lock(&data->page_mutex); + + if (!data->tx_buf || data->tx_buf_size < tx_size) { + if (data->tx_buf) + devm_kfree(&client->dev, data->tx_buf); + data->tx_buf_size = tx_size + BUFFER_SIZE_INCREMENT; + data->tx_buf = devm_kzalloc(&client->dev, data->tx_buf_size, + GFP_KERNEL); + if (!data->tx_buf) { + data->tx_buf_size = 0; + retval = -ENOMEM; + goto exit; + } + } + data->tx_buf[0] = addr & 0xff; + memcpy(data->tx_buf + 1, buf, len); + + if (RMI_I2C_PAGE(addr) != data->page) { + retval = rmi_set_page(phys, RMI_I2C_PAGE(addr)); + if (retval < 0) + goto exit; + } + + if (COMMS_DEBUG(data)) { + retval = copy_to_debug_buf(&client->dev, data, (u8 *) buf, len); + if (!retval) + dev_dbg(&client->dev, "writes %d bytes at %#06x:%s\n", + len, addr, data->debug_buf); + } + + phys->info.tx_count++; + phys->info.tx_bytes += tx_size; + retval = i2c_master_send(client, data->tx_buf, tx_size); + if (retval < 0) + phys->info.tx_errs++; + else + retval--; /* don't count the address byte */ + +exit: + mutex_unlock(&data->page_mutex); + return retval; +} + + +static int rmi_i2c_read_block(struct rmi_phys_device *phys, u16 addr, + void *buf, const int len) +{ + struct i2c_client *client = to_i2c_client(phys->dev); + struct rmi_i2c_data *data = phys->data; + u8 txbuf[1] = {addr & 0xff}; + int retval; + + mutex_lock(&data->page_mutex); + + if (RMI_I2C_PAGE(addr) != data->page) { + retval = rmi_set_page(phys, RMI_I2C_PAGE(addr)); + if (retval < 0) + goto exit; + } + + if (COMMS_DEBUG(data)) + dev_dbg(&client->dev, "writes 1 bytes: %02x\n", txbuf[0]); + + phys->info.tx_count++; + phys->info.tx_bytes += sizeof(txbuf); + retval = i2c_master_send(client, txbuf, sizeof(txbuf)); + if (retval != sizeof(txbuf)) { + phys->info.tx_errs++; + retval = (retval < 0) ? retval : -EIO; + goto exit; + } + + retval = i2c_master_recv(client, (u8 *) buf, len); + + phys->info.rx_count++; + phys->info.rx_bytes += len; + if (retval < 0) + phys->info.rx_errs++; + else if (COMMS_DEBUG(data)) { + retval = copy_to_debug_buf(&client->dev, data, (u8 *) buf, len); + if (!retval) + dev_dbg(&client->dev, "read %d bytes at %#06x:%s\n", + len, addr, data->debug_buf); + } + +exit: + mutex_unlock(&data->page_mutex); + return retval; +} + +static int __devinit rmi_i2c_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct rmi_phys_device *rmi_phys; + struct rmi_i2c_data *data; + struct rmi_device_platform_data *pdata = client->dev.platform_data; + int retval; + + if (!pdata) { + dev_err(&client->dev, "no platform data\n"); + return -EINVAL; + } + dev_info(&client->dev, "Probing %s at %#02x (IRQ %d).\n", + pdata->sensor_name ? pdata->sensor_name : "-no name-", + client->addr, pdata->attn_gpio); + + if (pdata->gpio_config) { + dev_info(&client->dev, "Configuring GPIOs.\n"); + retval = pdata->gpio_config(pdata->gpio_data, true); + if (retval < 0) { + dev_err(&client->dev, "Failed to configure GPIOs, code: %d.\n", + retval); + return retval; + } + dev_info(&client->dev, "Done with GPIO configuration.\n"); + } + + retval = i2c_check_functionality(client->adapter, I2C_FUNC_I2C); + if (!retval) { + dev_err(&client->dev, "i2c_check_functionality error %d.\n", + retval); + return retval; + } + + rmi_phys = devm_kzalloc(&client->dev, sizeof(struct rmi_phys_device), + GFP_KERNEL); + + if (!rmi_phys) + return -ENOMEM; + + data = devm_kzalloc(&client->dev, sizeof(struct rmi_i2c_data), + GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->phys = rmi_phys; + + rmi_phys->data = data; + rmi_phys->dev = &client->dev; + + rmi_phys->write_block = rmi_i2c_write_block; + rmi_phys->read_block = rmi_i2c_read_block; + rmi_phys->info.proto = phys_proto_name; + + mutex_init(&data->page_mutex); + + /* 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_phys, 0); + if (retval) { + dev_err(&client->dev, "Failed to set page select to 0.\n"); + return retval; + } + + retval = rmi_register_phys_device(rmi_phys); + if (retval) { + dev_err(&client->dev, + "failed to register physical driver at 0x%.2X.\n", + client->addr); + goto err_gpio; + } + i2c_set_clientdata(client, rmi_phys); + + if (IS_ENABLED(CONFIG_RMI4_DEBUG)) + retval = setup_debugfs(rmi_phys->rmi_dev, data); + + dev_info(&client->dev, "registered rmi i2c driver at %#04x.\n", + client->addr); + return 0; + +err_gpio: + if (pdata->gpio_config) + pdata->gpio_config(pdata->gpio_data, false); + return retval; +} + +static int __devexit rmi_i2c_remove(struct i2c_client *client) +{ + struct rmi_phys_device *phys = i2c_get_clientdata(client); + struct rmi_device_platform_data *pd = client->dev.platform_data; + + if (IS_ENABLED(CONFIG_RMI4_DEBUG)) + teardown_debugfs(phys->data); + + rmi_unregister_phys_device(phys); + + if (pd->gpio_config) + pd->gpio_config(&pd->gpio_data, false); + + 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 = __devexit_p(rmi_i2c_remove), +}; + +static int __init rmi_i2c_init(void) +{ + return i2c_add_driver(&rmi_i2c_driver); +} + +static void __exit rmi_i2c_exit(void) +{ + i2c_del_driver(&rmi_i2c_driver); +} + +module_init(rmi_i2c_init); +module_exit(rmi_i2c_exit); + +MODULE_AUTHOR("Christopher Heiny "); +MODULE_DESCRIPTION("RMI I2C driver"); +MODULE_LICENSE("GPL"); +MODULE_VERSION(RMI_DRIVER_VERSION); -- 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/