![Dmitry Torokhov](/assets/img/avatar_default.png)
We are not registering drivers, but transport devices (AKA sensors), so let's call them that. Also let's rename "retval" to "error" in probe() functions as the variables are used to store error codes. Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
395 lines
9.4 KiB
C
395 lines
9.4 KiB
C
/*
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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/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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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 <cheiny@synaptics.com>");
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MODULE_AUTHOR("Andrew Duggan <aduggan@synaptics.com>");
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MODULE_DESCRIPTION("RMI I2C driver");
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MODULE_LICENSE("GPL");
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MODULE_VERSION(RMI_DRIVER_VERSION);
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