458 lines
11 KiB
C
458 lines
11 KiB
C
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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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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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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/irq.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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*
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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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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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int irq;
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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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static irqreturn_t rmi_i2c_irq(int irq, void *dev_id)
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{
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struct rmi_i2c_xport *rmi_i2c = dev_id;
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struct rmi_device *rmi_dev = rmi_i2c->xport.rmi_dev;
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int ret;
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ret = rmi_process_interrupt_requests(rmi_dev);
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if (ret)
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rmi_dbg(RMI_DEBUG_XPORT, &rmi_dev->dev,
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"Failed to process interrupt request: %d\n", ret);
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return IRQ_HANDLED;
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}
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static int rmi_i2c_init_irq(struct i2c_client *client)
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{
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struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client);
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int irq_flags = irqd_get_trigger_type(irq_get_irq_data(rmi_i2c->irq));
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int ret;
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if (!irq_flags)
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irq_flags = IRQF_TRIGGER_LOW;
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ret = devm_request_threaded_irq(&client->dev, rmi_i2c->irq, NULL,
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rmi_i2c_irq, irq_flags | IRQF_ONESHOT, client->name,
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rmi_i2c);
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if (ret < 0) {
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dev_warn(&client->dev, "Failed to register interrupt %d\n",
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rmi_i2c->irq);
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return ret;
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}
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return 0;
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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 retval;
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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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if (client->irq > 0)
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rmi_i2c->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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retval = 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 (retval < 0)
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return retval;
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retval = regulator_bulk_enable(ARRAY_SIZE(rmi_i2c->supplies),
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rmi_i2c->supplies);
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if (retval < 0)
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return retval;
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retval = 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 (retval)
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return retval;
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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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retval = rmi_set_page(rmi_i2c, 0);
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if (retval) {
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dev_err(&client->dev, "Failed to set page select to 0.\n");
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return retval;
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}
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retval = rmi_register_transport_device(&rmi_i2c->xport);
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if (retval) {
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dev_err(&client->dev, "Failed to register transport driver at 0x%.2X.\n",
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client->addr);
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return retval;
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}
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retval = 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 (retval)
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return retval;
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retval = rmi_i2c_init_irq(client);
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if (retval < 0)
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return retval;
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dev_info(&client->dev, "registered rmi i2c driver at %#04x.\n",
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client->addr);
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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);
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if (ret)
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dev_warn(dev, "Failed to resume device: %d\n", ret);
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disable_irq(rmi_i2c->irq);
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if (device_may_wakeup(&client->dev)) {
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ret = enable_irq_wake(rmi_i2c->irq);
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if (!ret)
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dev_warn(dev, "Failed to enable irq for wake: %d\n",
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ret);
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}
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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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enable_irq(rmi_i2c->irq);
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if (device_may_wakeup(&client->dev)) {
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ret = disable_irq_wake(rmi_i2c->irq);
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if (!ret)
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dev_warn(dev, "Failed to disable irq for wake: %d\n",
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ret);
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}
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ret = rmi_driver_resume(rmi_i2c->xport.rmi_dev);
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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);
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if (ret)
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dev_warn(dev, "Failed to resume device: %d\n", ret);
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disable_irq(rmi_i2c->irq);
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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)
|
||
|
return ret;
|
||
|
|
||
|
msleep(rmi_i2c->startup_delay);
|
||
|
|
||
|
enable_irq(rmi_i2c->irq);
|
||
|
|
||
|
ret = rmi_driver_resume(rmi_i2c->xport.rmi_dev);
|
||
|
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);
|