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/*
* Copyright 1996,2002,2005 Gregory D. Hager, Alfred A. Rizzi, Noah J. Cowan,
* Jason Lapenta, Scott Smedley
*
* This file is part of the DT3155 Device Driver.
*
* The DT3155 Device Driver is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* The DT3155 Device Driver is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
* Public License for more details.
*/
/*
* This file provides some basic register io routines. It is modified from
* demo code provided by Data Translations.
*/
#include <linux/delay.h>
#include <linux/io.h>
#include "dt3155.h"
#include "dt3155_io.h"
#include "dt3155_drv.h"
/*
* wait_ibsyclr()
*
* This function handles read/write timing and r/w timeout error
*/
static int wait_ibsyclr(void __iomem *mmio)
{
IIC_CSR2_R iic_csr2_r;
/* wait 100 microseconds */
udelay(100L);
/* __delay(loops_per_sec/10000); */
iic_csr2_r.reg = readl(mmio + IIC_CSR2);
if (iic_csr2_r.fld.NEW_CYCLE) {
/* if NEW_CYCLE didn't clear */
/* TIMEOUT ERROR */
dt3155_errno = DT_ERR_I2C_TIMEOUT;
return -ETIMEDOUT;
}
return 0; /* no error */
}
/*
* WriteI2C()
*
* This function handles writing to 8-bit DT3155 registers
*
* 1st parameter is pointer to 32-bit register base address
* 2nd parameter is reg. index;
* 3rd is value to be written
*/
int WriteI2C(void __iomem *mmio, u_short wIregIndex, u8 byVal)
{
IIC_CSR2_R iic_csr2_r;
/* read 32 bit IIC_CSR2 register data into union */
iic_csr2_r.reg = readl(mmio + IIC_CSR2);
/* for write operation */
iic_csr2_r.fld.DIR_RD = 0;
/* I2C address of I2C register: */
iic_csr2_r.fld.DIR_ADDR = wIregIndex;
/* 8 bit data to be written to I2C reg */
iic_csr2_r.fld.DIR_WR_DATA = byVal;
/* will start a direct I2C cycle: */
iic_csr2_r.fld.NEW_CYCLE = 1;
/* xfer union data into 32 bit IIC_CSR2 register */
writel(iic_csr2_r.reg, mmio + IIC_CSR2);
/* wait for IIC cycle to finish */
return wait_ibsyclr(mmio);
}
/*
* ReadI2C()
*
* This function handles reading from 8-bit DT3155 registers
*
* 1st parameter is pointer to 32-bit register base address
* 2nd parameter is reg. index;
* 3rd is adrs of value to be read
*/
int ReadI2C(void __iomem *mmio, u_short wIregIndex, u8 *byVal)
{
IIC_CSR1_R iic_csr1_r;
IIC_CSR2_R iic_csr2_r;
int writestat; /* status for return */
/* read 32 bit IIC_CSR2 register data into union */
iic_csr2_r.reg = readl(mmio + IIC_CSR2);
/* for read operation */
iic_csr2_r.fld.DIR_RD = 1;
/* I2C address of I2C register: */
iic_csr2_r.fld.DIR_ADDR = wIregIndex;
/* will start a direct I2C cycle: */
iic_csr2_r.fld.NEW_CYCLE = 1;
/* xfer union's data into 32 bit IIC_CSR2 register */
writel(iic_csr2_r.reg, mmio + IIC_CSR2);
/* wait for IIC cycle to finish */
writestat = wait_ibsyclr(mmio);
/* Next 2 commands read 32 bit IIC_CSR1 register's data into union */
/* first read data is in IIC_CSR1 */
iic_csr1_r.reg = readl(mmio + IIC_CSR1);
/* now get data u8 out of register */
*byVal = (u8) iic_csr1_r.fld.RD_DATA;
return writestat;
}
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