| /* |
| * Copyright (c) 2011-2016 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 <linux/i2c.h> |
| #include <linux/rmi.h> |
| #include <linux/of.h> |
| #include <linux/delay.h> |
| #include <linux/regulator/consumer.h> |
| #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; |
| |
| struct regulator_bulk_data supplies[2]; |
| u32 startup_delay; |
| }; |
| |
| #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: |
| rmi_dbg(RMI_DEBUG_XPORT, &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: |
| rmi_dbg(RMI_DEBUG_XPORT, &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, |
| }; |
| |
| #ifdef CONFIG_OF |
| static const struct of_device_id rmi_i2c_of_match[] = { |
| { .compatible = "syna,rmi4-i2c" }, |
| {}, |
| }; |
| MODULE_DEVICE_TABLE(of, rmi_i2c_of_match); |
| #endif |
| |
| static void rmi_i2c_regulator_bulk_disable(void *data) |
| { |
| struct rmi_i2c_xport *rmi_i2c = data; |
| |
| regulator_bulk_disable(ARRAY_SIZE(rmi_i2c->supplies), |
| rmi_i2c->supplies); |
| } |
| |
| static void rmi_i2c_unregister_transport(void *data) |
| { |
| struct rmi_i2c_xport *rmi_i2c = data; |
| |
| rmi_unregister_transport_device(&rmi_i2c->xport); |
| } |
| |
| 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->dev.of_node && client_pdata) |
| *pdata = *client_pdata; |
| |
| pdata->irq = client->irq; |
| |
| rmi_dbg(RMI_DEBUG_XPORT, &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->supplies[0].supply = "vdd"; |
| rmi_i2c->supplies[1].supply = "vio"; |
| retval = devm_regulator_bulk_get(&client->dev, |
| ARRAY_SIZE(rmi_i2c->supplies), |
| rmi_i2c->supplies); |
| if (retval < 0) |
| return retval; |
| |
| retval = regulator_bulk_enable(ARRAY_SIZE(rmi_i2c->supplies), |
| rmi_i2c->supplies); |
| if (retval < 0) |
| return retval; |
| |
| retval = devm_add_action_or_reset(&client->dev, |
| rmi_i2c_regulator_bulk_disable, |
| rmi_i2c); |
| if (retval) |
| return retval; |
| |
| of_property_read_u32(client->dev.of_node, "syna,startup-delay-ms", |
| &rmi_i2c->startup_delay); |
| |
| msleep(rmi_i2c->startup_delay); |
| |
| 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; |
| |
| i2c_set_clientdata(client, rmi_i2c); |
| |
| /* |
| * 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; |
| } |
| retval = devm_add_action_or_reset(&client->dev, |
| rmi_i2c_unregister_transport, |
| rmi_i2c); |
| if (retval) |
| return retval; |
| |
| dev_info(&client->dev, "registered rmi i2c driver at %#04x.\n", |
| client->addr); |
| return 0; |
| } |
| |
| #ifdef CONFIG_PM_SLEEP |
| static int rmi_i2c_suspend(struct device *dev) |
| { |
| struct i2c_client *client = to_i2c_client(dev); |
| struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client); |
| int ret; |
| |
| ret = rmi_driver_suspend(rmi_i2c->xport.rmi_dev, true); |
| if (ret) |
| dev_warn(dev, "Failed to resume device: %d\n", ret); |
| |
| regulator_bulk_disable(ARRAY_SIZE(rmi_i2c->supplies), |
| rmi_i2c->supplies); |
| |
| return ret; |
| } |
| |
| static int rmi_i2c_resume(struct device *dev) |
| { |
| struct i2c_client *client = to_i2c_client(dev); |
| struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client); |
| int ret; |
| |
| ret = regulator_bulk_enable(ARRAY_SIZE(rmi_i2c->supplies), |
| rmi_i2c->supplies); |
| if (ret) |
| return ret; |
| |
| msleep(rmi_i2c->startup_delay); |
| |
| ret = rmi_driver_resume(rmi_i2c->xport.rmi_dev, true); |
| if (ret) |
| dev_warn(dev, "Failed to resume device: %d\n", ret); |
| |
| return ret; |
| } |
| #endif |
| |
| #ifdef CONFIG_PM |
| static int rmi_i2c_runtime_suspend(struct device *dev) |
| { |
| struct i2c_client *client = to_i2c_client(dev); |
| struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client); |
| int ret; |
| |
| ret = rmi_driver_suspend(rmi_i2c->xport.rmi_dev, false); |
| if (ret) |
| dev_warn(dev, "Failed to resume device: %d\n", ret); |
| |
| regulator_bulk_disable(ARRAY_SIZE(rmi_i2c->supplies), |
| rmi_i2c->supplies); |
| |
| return 0; |
| } |
| |
| static int rmi_i2c_runtime_resume(struct device *dev) |
| { |
| struct i2c_client *client = to_i2c_client(dev); |
| struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client); |
| int ret; |
| |
| ret = regulator_bulk_enable(ARRAY_SIZE(rmi_i2c->supplies), |
| rmi_i2c->supplies); |
| if (ret) |
| return ret; |
| |
| msleep(rmi_i2c->startup_delay); |
| |
| ret = rmi_driver_resume(rmi_i2c->xport.rmi_dev, false); |
| if (ret) |
| dev_warn(dev, "Failed to resume device: %d\n", ret); |
| |
| return 0; |
| } |
| #endif |
| |
| static const struct dev_pm_ops rmi_i2c_pm = { |
| SET_SYSTEM_SLEEP_PM_OPS(rmi_i2c_suspend, rmi_i2c_resume) |
| SET_RUNTIME_PM_OPS(rmi_i2c_runtime_suspend, rmi_i2c_runtime_resume, |
| NULL) |
| }; |
| |
| static const struct i2c_device_id rmi_id[] = { |
| { "rmi4_i2c", 0 }, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(i2c, rmi_id); |
| |
| static struct i2c_driver rmi_i2c_driver = { |
| .driver = { |
| .name = "rmi4_i2c", |
| .pm = &rmi_i2c_pm, |
| .of_match_table = of_match_ptr(rmi_i2c_of_match), |
| }, |
| .id_table = rmi_id, |
| .probe = rmi_i2c_probe, |
| }; |
| |
| module_i2c_driver(rmi_i2c_driver); |
| |
| MODULE_AUTHOR("Christopher Heiny <cheiny@synaptics.com>"); |
| MODULE_AUTHOR("Andrew Duggan <aduggan@synaptics.com>"); |
| MODULE_DESCRIPTION("RMI I2C driver"); |
| MODULE_LICENSE("GPL"); |
| MODULE_VERSION(RMI_DRIVER_VERSION); |