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394 lines
9.4 KiB
394 lines
9.4 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Copyright (c) 2011-2016 Synaptics Incorporated |
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* Copyright (c) 2011 Unixphere |
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*/ |
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#include <linux/i2c.h> |
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#include <linux/rmi.h> |
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#include <linux/of.h> |
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#include <linux/delay.h> |
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#include <linux/regulator/consumer.h> |
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#include "rmi_driver.h" |
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#define BUFFER_SIZE_INCREMENT 32 |
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/** |
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* struct rmi_i2c_xport - stores information for i2c communication |
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* |
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* @xport: The transport interface structure |
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* @client: The I2C client device structure |
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* |
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* @page_mutex: Locks current page to avoid changing pages in unexpected ways. |
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* @page: Keeps track of the current virtual page |
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* |
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* @tx_buf: Buffer used for transmitting data to the sensor over i2c. |
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* @tx_buf_size: Size of the buffer |
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* |
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* @supplies: Array of voltage regulators |
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* @startup_delay: Milliseconds to pause after powering up the regulators |
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*/ |
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struct rmi_i2c_xport { |
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struct rmi_transport_dev xport; |
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struct i2c_client *client; |
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struct mutex page_mutex; |
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int page; |
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u8 *tx_buf; |
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size_t tx_buf_size; |
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struct regulator_bulk_data supplies[2]; |
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u32 startup_delay; |
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}; |
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#define RMI_PAGE_SELECT_REGISTER 0xff |
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#define RMI_I2C_PAGE(addr) (((addr) >> 8) & 0xff) |
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/* |
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* rmi_set_page - Set RMI page |
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* @xport: The pointer to the rmi_transport_dev struct |
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* @page: The new page address. |
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* |
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* RMI devices have 16-bit addressing, but some of the transport |
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* implementations (like SMBus) only have 8-bit addressing. So RMI implements |
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* a page address at 0xff of every page so we can reliable page addresses |
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* every 256 registers. |
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* |
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* The page_mutex lock must be held when this function is entered. |
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* |
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* Returns zero on success, non-zero on failure. |
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*/ |
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static int rmi_set_page(struct rmi_i2c_xport *rmi_i2c, u8 page) |
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{ |
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struct i2c_client *client = rmi_i2c->client; |
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u8 txbuf[2] = {RMI_PAGE_SELECT_REGISTER, page}; |
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int retval; |
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retval = i2c_master_send(client, txbuf, sizeof(txbuf)); |
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if (retval != sizeof(txbuf)) { |
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dev_err(&client->dev, |
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"%s: set page failed: %d.", __func__, retval); |
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return (retval < 0) ? retval : -EIO; |
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} |
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rmi_i2c->page = page; |
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return 0; |
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} |
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static int rmi_i2c_write_block(struct rmi_transport_dev *xport, u16 addr, |
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const void *buf, size_t len) |
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{ |
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struct rmi_i2c_xport *rmi_i2c = |
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container_of(xport, struct rmi_i2c_xport, xport); |
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struct i2c_client *client = rmi_i2c->client; |
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size_t tx_size = len + 1; |
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int retval; |
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mutex_lock(&rmi_i2c->page_mutex); |
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if (!rmi_i2c->tx_buf || rmi_i2c->tx_buf_size < tx_size) { |
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if (rmi_i2c->tx_buf) |
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devm_kfree(&client->dev, rmi_i2c->tx_buf); |
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rmi_i2c->tx_buf_size = tx_size + BUFFER_SIZE_INCREMENT; |
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rmi_i2c->tx_buf = devm_kzalloc(&client->dev, |
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rmi_i2c->tx_buf_size, |
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GFP_KERNEL); |
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if (!rmi_i2c->tx_buf) { |
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rmi_i2c->tx_buf_size = 0; |
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retval = -ENOMEM; |
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goto exit; |
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} |
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} |
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rmi_i2c->tx_buf[0] = addr & 0xff; |
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memcpy(rmi_i2c->tx_buf + 1, buf, len); |
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if (RMI_I2C_PAGE(addr) != rmi_i2c->page) { |
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retval = rmi_set_page(rmi_i2c, RMI_I2C_PAGE(addr)); |
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if (retval) |
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goto exit; |
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} |
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retval = i2c_master_send(client, rmi_i2c->tx_buf, tx_size); |
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if (retval == tx_size) |
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retval = 0; |
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else if (retval >= 0) |
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retval = -EIO; |
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exit: |
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rmi_dbg(RMI_DEBUG_XPORT, &client->dev, |
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"write %zd bytes at %#06x: %d (%*ph)\n", |
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len, addr, retval, (int)len, buf); |
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mutex_unlock(&rmi_i2c->page_mutex); |
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return retval; |
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} |
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static int rmi_i2c_read_block(struct rmi_transport_dev *xport, u16 addr, |
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void *buf, size_t len) |
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{ |
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struct rmi_i2c_xport *rmi_i2c = |
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container_of(xport, struct rmi_i2c_xport, xport); |
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struct i2c_client *client = rmi_i2c->client; |
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u8 addr_offset = addr & 0xff; |
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int retval; |
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struct i2c_msg msgs[] = { |
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{ |
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.addr = client->addr, |
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.len = sizeof(addr_offset), |
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.buf = &addr_offset, |
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}, |
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{ |
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.addr = client->addr, |
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.flags = I2C_M_RD, |
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.len = len, |
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.buf = buf, |
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}, |
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}; |
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mutex_lock(&rmi_i2c->page_mutex); |
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if (RMI_I2C_PAGE(addr) != rmi_i2c->page) { |
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retval = rmi_set_page(rmi_i2c, RMI_I2C_PAGE(addr)); |
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if (retval) |
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goto exit; |
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} |
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retval = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); |
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if (retval == ARRAY_SIZE(msgs)) |
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retval = 0; /* success */ |
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else if (retval >= 0) |
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retval = -EIO; |
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exit: |
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rmi_dbg(RMI_DEBUG_XPORT, &client->dev, |
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"read %zd bytes at %#06x: %d (%*ph)\n", |
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len, addr, retval, (int)len, buf); |
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mutex_unlock(&rmi_i2c->page_mutex); |
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return retval; |
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} |
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static const struct rmi_transport_ops rmi_i2c_ops = { |
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.write_block = rmi_i2c_write_block, |
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.read_block = rmi_i2c_read_block, |
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}; |
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#ifdef CONFIG_OF |
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static const struct of_device_id rmi_i2c_of_match[] = { |
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{ .compatible = "syna,rmi4-i2c" }, |
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{}, |
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}; |
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MODULE_DEVICE_TABLE(of, rmi_i2c_of_match); |
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#endif |
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static void rmi_i2c_regulator_bulk_disable(void *data) |
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{ |
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struct rmi_i2c_xport *rmi_i2c = data; |
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regulator_bulk_disable(ARRAY_SIZE(rmi_i2c->supplies), |
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rmi_i2c->supplies); |
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} |
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static void rmi_i2c_unregister_transport(void *data) |
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{ |
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struct rmi_i2c_xport *rmi_i2c = data; |
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rmi_unregister_transport_device(&rmi_i2c->xport); |
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} |
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static int rmi_i2c_probe(struct i2c_client *client, |
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const struct i2c_device_id *id) |
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{ |
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struct rmi_device_platform_data *pdata; |
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struct rmi_device_platform_data *client_pdata = |
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dev_get_platdata(&client->dev); |
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struct rmi_i2c_xport *rmi_i2c; |
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int error; |
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rmi_i2c = devm_kzalloc(&client->dev, sizeof(struct rmi_i2c_xport), |
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GFP_KERNEL); |
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if (!rmi_i2c) |
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return -ENOMEM; |
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pdata = &rmi_i2c->xport.pdata; |
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if (!client->dev.of_node && client_pdata) |
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*pdata = *client_pdata; |
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pdata->irq = client->irq; |
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rmi_dbg(RMI_DEBUG_XPORT, &client->dev, "Probing %s.\n", |
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dev_name(&client->dev)); |
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if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { |
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dev_err(&client->dev, |
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"adapter does not support required functionality\n"); |
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return -ENODEV; |
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} |
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rmi_i2c->supplies[0].supply = "vdd"; |
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rmi_i2c->supplies[1].supply = "vio"; |
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error = devm_regulator_bulk_get(&client->dev, |
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ARRAY_SIZE(rmi_i2c->supplies), |
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rmi_i2c->supplies); |
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if (error < 0) |
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return error; |
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error = regulator_bulk_enable(ARRAY_SIZE(rmi_i2c->supplies), |
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rmi_i2c->supplies); |
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if (error < 0) |
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return error; |
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error = devm_add_action_or_reset(&client->dev, |
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rmi_i2c_regulator_bulk_disable, |
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rmi_i2c); |
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if (error) |
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return error; |
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of_property_read_u32(client->dev.of_node, "syna,startup-delay-ms", |
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&rmi_i2c->startup_delay); |
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msleep(rmi_i2c->startup_delay); |
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rmi_i2c->client = client; |
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mutex_init(&rmi_i2c->page_mutex); |
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rmi_i2c->xport.dev = &client->dev; |
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rmi_i2c->xport.proto_name = "i2c"; |
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rmi_i2c->xport.ops = &rmi_i2c_ops; |
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i2c_set_clientdata(client, rmi_i2c); |
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/* |
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* Setting the page to zero will (a) make sure the PSR is in a |
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* known state, and (b) make sure we can talk to the device. |
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*/ |
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error = rmi_set_page(rmi_i2c, 0); |
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if (error) { |
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dev_err(&client->dev, "Failed to set page select to 0\n"); |
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return error; |
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} |
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dev_info(&client->dev, "registering I2C-connected sensor\n"); |
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error = rmi_register_transport_device(&rmi_i2c->xport); |
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if (error) { |
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dev_err(&client->dev, "failed to register sensor: %d\n", error); |
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return error; |
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} |
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error = devm_add_action_or_reset(&client->dev, |
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rmi_i2c_unregister_transport, |
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rmi_i2c); |
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if (error) |
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return error; |
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return 0; |
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} |
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#ifdef CONFIG_PM_SLEEP |
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static int rmi_i2c_suspend(struct device *dev) |
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{ |
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struct i2c_client *client = to_i2c_client(dev); |
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struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client); |
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int ret; |
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ret = rmi_driver_suspend(rmi_i2c->xport.rmi_dev, true); |
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if (ret) |
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dev_warn(dev, "Failed to resume device: %d\n", ret); |
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regulator_bulk_disable(ARRAY_SIZE(rmi_i2c->supplies), |
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rmi_i2c->supplies); |
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return ret; |
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} |
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static int rmi_i2c_resume(struct device *dev) |
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{ |
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struct i2c_client *client = to_i2c_client(dev); |
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struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client); |
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int ret; |
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ret = regulator_bulk_enable(ARRAY_SIZE(rmi_i2c->supplies), |
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rmi_i2c->supplies); |
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if (ret) |
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return ret; |
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msleep(rmi_i2c->startup_delay); |
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ret = rmi_driver_resume(rmi_i2c->xport.rmi_dev, true); |
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if (ret) |
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dev_warn(dev, "Failed to resume device: %d\n", ret); |
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return ret; |
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} |
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#endif |
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#ifdef CONFIG_PM |
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static int rmi_i2c_runtime_suspend(struct device *dev) |
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{ |
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struct i2c_client *client = to_i2c_client(dev); |
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struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client); |
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int ret; |
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ret = rmi_driver_suspend(rmi_i2c->xport.rmi_dev, false); |
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if (ret) |
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dev_warn(dev, "Failed to resume device: %d\n", ret); |
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regulator_bulk_disable(ARRAY_SIZE(rmi_i2c->supplies), |
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rmi_i2c->supplies); |
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return 0; |
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} |
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static int rmi_i2c_runtime_resume(struct device *dev) |
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{ |
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struct i2c_client *client = to_i2c_client(dev); |
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struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client); |
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int ret; |
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ret = regulator_bulk_enable(ARRAY_SIZE(rmi_i2c->supplies), |
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rmi_i2c->supplies); |
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if (ret) |
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return ret; |
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msleep(rmi_i2c->startup_delay); |
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ret = rmi_driver_resume(rmi_i2c->xport.rmi_dev, false); |
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if (ret) |
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dev_warn(dev, "Failed to resume device: %d\n", ret); |
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return 0; |
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} |
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#endif |
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static const struct dev_pm_ops rmi_i2c_pm = { |
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SET_SYSTEM_SLEEP_PM_OPS(rmi_i2c_suspend, rmi_i2c_resume) |
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SET_RUNTIME_PM_OPS(rmi_i2c_runtime_suspend, rmi_i2c_runtime_resume, |
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NULL) |
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}; |
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static const struct i2c_device_id rmi_id[] = { |
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{ "rmi4_i2c", 0 }, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(i2c, rmi_id); |
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static struct i2c_driver rmi_i2c_driver = { |
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.driver = { |
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.name = "rmi4_i2c", |
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.pm = &rmi_i2c_pm, |
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.of_match_table = of_match_ptr(rmi_i2c_of_match), |
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}, |
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.id_table = rmi_id, |
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.probe = rmi_i2c_probe, |
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}; |
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module_i2c_driver(rmi_i2c_driver); |
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MODULE_AUTHOR("Christopher Heiny <[email protected]>"); |
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MODULE_AUTHOR("Andrew Duggan <[email protected]>"); |
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MODULE_DESCRIPTION("RMI I2C driver"); |
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MODULE_LICENSE("GPL");
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