The I2C physical driver is not extensively changed in terms of functionality
since the previous patch.  Management of the attention GPIO has been moved to
rmi_driver.c (see previous email), and most of the debug related interfaces
have been moved from sysfs to debugfs.  Control of the debug features has been
moved from compile-time to runtime switches available via debugfs.

The core I2C functionality was previously ACKed by Jean Delvare.  I don't
believe that portion of the code has changed much since then, but we'd
appreciate a second glance at this.


Signed-off-by: Christopher Heiny <che...@synaptics.com>

Cc: Dmitry Torokhov <dmitry.torok...@gmail.com>
Cc: Linus Walleij <linus.wall...@stericsson.com>
Cc: Naveen Kumar Gaddipati <naveen.gaddip...@stericsson.com>
Cc: Joeri de Gram <j.de.g...@gmail.com>
Cc: Jean Delvare <kh...@linux-fr.org>

Acked-by: Jean Delvare <kh...@linux-fr.org>

---

 drivers/input/rmi4/rmi_i2c.c |  455 ++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 455 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..c21a27c
--- /dev/null
+++ b/drivers/input/rmi4/rmi_i2c.c
@@ -0,0 +1,455 @@
+/*
+ * 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 <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/gpio.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/kconfig.h>
+#include <linux/lockdep.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/rmi.h>
+#include <linux/slab.h>
+#include "rmi_driver.h"
+
+struct rmi_i2c_data {
+       struct mutex page_mutex;
+       int page;
+       struct rmi_phys_device *phys;
+
+       bool comms_debug;
+#ifdef CONFIG_RMI4_DEBUG
+       struct dentry *debugfs_comms;
+#endif
+};
+
+#ifdef CONFIG_RMI4_DEBUG
+
+#include <linux/debugfs.h>
+#include <linux/uaccess.h>
+
+static int setup_debugfs(struct rmi_device *rmi_dev, struct rmi_i2c_data 
*data);
+static void teardown_debugfs(struct rmi_i2c_data *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[size];
+       struct i2c_debugfs_data *dfs = filp->private_data;
+       struct rmi_i2c_data *data = dfs->i2c_data;
+
+       if (dfs->done)
+               return 0;
+
+       dfs->done = 1;
+
+       retval = snprintf(local_buf, PAGE_SIZE, "%u\n", data->comms_debug);
+
+       if (retval <= 0 || copy_to_user(buffer, local_buf, retval))
+               return -EFAULT;
+
+       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[size];
+       unsigned int new_value;
+       struct i2c_debugfs_data *dfs = filp->private_data;
+       struct rmi_i2c_data *data = dfs->i2c_data;
+
+       retval = copy_from_user(local_buf, buffer, size);
+       if (retval)
+               return -EFAULT;
+
+       retval = sscanf(local_buf, "%u", &new_value);
+       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 rmi_i2c_write_block(struct rmi_phys_device *phys, u16 addr, u8 *buf,
+                              int len)
+{
+       struct i2c_client *client = to_i2c_client(phys->dev);
+       struct rmi_i2c_data *data = phys->data;
+       u8 txbuf[len + 1];
+       int retval;
+
+       txbuf[0] = addr & 0xff;
+       memcpy(txbuf + 1, buf, len);
+
+       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)) {
+               char debug_buf[len*3 + 1];
+               int i;
+               int n = 0;
+               char *temp = debug_buf;
+
+               for (i = 0; i < len; i++) {
+                       n = sprintf(temp, " %02x", buf[i]);
+                       temp += n;
+               }
+               dev_dbg(&client->dev, "writes %d bytes at %#06x:%s\n",
+                       len, addr, debug_buf);
+       }
+
+       phys->info.tx_count++;
+       phys->info.tx_bytes += sizeof(txbuf);
+       retval = i2c_master_send(client, txbuf, sizeof(txbuf));
+       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, u8 *buf,
+                             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, buf, len);
+
+       phys->info.rx_count++;
+       phys->info.rx_bytes += len;
+       if (retval < 0)
+               phys->info.rx_errs++;
+       else if (COMMS_DEBUG(data)) {
+               char debug_buf[len*3 + 1];
+               char *temp = debug_buf;
+               int i;
+               int n = 0;
+
+               for (i = 0; i < len; i++) {
+                       n = sprintf(temp, " %02x", buf[i]);
+                       temp += n;
+               }
+               dev_dbg(&client->dev, "read %d bytes at %#06x:%s\n",
+                       len, addr, 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 = kzalloc(sizeof(struct rmi_phys_device), GFP_KERNEL);
+       if (!rmi_phys)
+               return -ENOMEM;
+
+       data = kzalloc(sizeof(struct rmi_i2c_data), GFP_KERNEL);
+       if (!data) {
+               retval = -ENOMEM;
+               goto err_phys;
+       }
+
+       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");
+               goto err_data;
+       }
+
+       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);
+
+       if (IS_ENABLED(CONFIG_RMI4_DEV)) {
+               retval = gpio_export(pdata->attn_gpio, false);
+               if (retval) {
+                       dev_warn(&client->dev,
+                               "WARNING: Failed to export ATTN gpio!\n");
+                       retval = 0;
+               } else {
+                       retval = gpio_export_link(&client->dev,
+                                                 "attn", pdata->attn_gpio);
+                       if (retval) {
+                               dev_warn(&client->dev,
+                                       "WARNING: Failed to symlink ATTN 
gpio!\n");
+                               retval = 0;
+                       } else {
+                               dev_info(&client->dev, "Exported ATTN GPIO %d.",
+                                       pdata->attn_gpio);
+                       }
+               }
+       }
+
+       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);
+err_data:
+       kfree(data);
+err_phys:
+       kfree(rmi_phys);
+       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;
+
+       /* Can I remove this disable_device */
+       /*disable_device(phys); */
+
+       if (IS_ENABLED(CONFIG_RMI4_DEBUG))
+               teardown_debugfs(phys->data);
+
+       rmi_unregister_phys_device(phys);
+       kfree(phys->data);
+       kfree(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 <che...@synaptics.com>");
+MODULE_DESCRIPTION("RMI I2C driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(RMI_DRIVER_VERSION);
--
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