158 lines
3.1 KiB
C
158 lines
3.1 KiB
C
/*
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* Copyright (C) 2011 Alexander Aring <a.aring@phytec.de>
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*
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* Based on:
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* Copyright (C) 2010 Michael Grzeschik <mgr@pengutronix.de>
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*
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* This file is released under the GPLv2
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*
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*/
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#include <common.h>
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#include <init.h>
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#include <driver.h>
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#include <xfuncs.h>
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#include <errno.h>
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#include <i2c/i2c.h>
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#include <mfd/twl-core.h>
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#define to_twlcore(a) container_of(a, struct twlcore, cdev)
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static struct twlcore *twl_dev;
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struct twlcore *twlcore_get(void)
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{
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return twl_dev;
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}
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EXPORT_SYMBOL(twlcore_get);
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int twlcore_reg_read(struct twlcore *twlcore, u16 reg, u8 *val)
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{
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int ret;
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struct i2c_msg xfer_msg[2];
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struct i2c_msg *msg;
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int i2c_addr;
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unsigned char buf = reg & 0xff;
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i2c_addr = twlcore->client->addr + (reg / 0x100);
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/* [MSG1] fill the register address data */
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msg = &xfer_msg[0];
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msg->addr = i2c_addr;
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msg->len = 1;
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msg->flags = 0;
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msg->buf = &buf;
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/* [MSG2] fill the data rx buffer */
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msg = &xfer_msg[1];
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msg->addr = i2c_addr;
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msg->flags = I2C_M_RD;
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msg->len = 1; /* only n bytes */
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msg->buf = val;
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ret = i2c_transfer(twlcore->client->adapter, xfer_msg, 2);
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/* i2c_transfer returns number of messages transferred */
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if (ret < 0) {
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pr_err("%s: failed to transfer all messages: %s\n",
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__func__, strerror(-ret));
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return ret;
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}
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return 0;
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}
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EXPORT_SYMBOL(twlcore_reg_read);
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int twlcore_reg_write(struct twlcore *twlcore, u16 reg, u8 val)
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{
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int ret;
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struct i2c_msg xfer_msg[1];
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struct i2c_msg *msg;
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int i2c_addr;
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u8 buf[2];
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buf[0] = reg & 0xff;
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buf[1] = val;
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i2c_addr = twlcore->client->addr + (reg / 0x100);
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/*
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* [MSG1]: fill the register address data
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* fill the data Tx buffer
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*/
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msg = xfer_msg;
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msg->addr = i2c_addr;
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msg->len = 2;
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msg->flags = 0;
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msg->buf = buf;
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/* over write the first byte of buffer with the register address */
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ret = i2c_transfer(twlcore->client->adapter, xfer_msg, 1);
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/* i2c_transfer returns number of messages transferred */
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if (ret < 0) {
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pr_err("%s: failed to transfer all messages: %s\n",
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__func__, strerror(-ret));
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return ret;
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}
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return 0;
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}
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EXPORT_SYMBOL(twlcore_reg_write);
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int twlcore_set_bits(struct twlcore *twlcore, u16 reg, u8 mask, u8 val)
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{
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u8 tmp;
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int ret;
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ret = twlcore_reg_read(twlcore, reg, &tmp);
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tmp = (tmp & ~mask) | val;
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if (ret)
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ret = twlcore_reg_write(twlcore, reg, tmp);
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return ret;
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}
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EXPORT_SYMBOL(twlcore_set_bits);
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static ssize_t twl_read(struct cdev *cdev, void *_buf, size_t count,
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loff_t offset, ulong flags)
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{
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struct twlcore *priv = to_twlcore(cdev);
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u8 *buf = _buf;
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size_t i;
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int ret;
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for (i = 0; i < count; i++) {
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ret = twlcore_reg_read(priv, offset, buf);
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if (ret)
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return (ssize_t)ret;
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buf++;
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offset++;
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}
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return count;
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}
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static ssize_t twl_write(struct cdev *cdev, const void *_buf, size_t count,
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loff_t offset, ulong flags)
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{
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struct twlcore *twlcore = to_twlcore(cdev);
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const u8 *buf = _buf;
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size_t i;
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int ret;
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for (i = 0; i < count; i++) {
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ret = twlcore_reg_write(twlcore, offset, *buf);
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if (ret)
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return (ssize_t)ret;
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buf++;
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offset++;
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}
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return count;
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}
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struct file_operations twl_fops = {
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.lseek = dev_lseek_default,
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.read = twl_read,
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.write = twl_write,
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};
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EXPORT_SYMBOL(twl_fops);
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