diff options
Diffstat (limited to 'arch/cris/arch-v10/drivers/i2c.c')
| -rw-r--r-- | arch/cris/arch-v10/drivers/i2c.c | 699 |
1 files changed, 0 insertions, 699 deletions
diff --git a/arch/cris/arch-v10/drivers/i2c.c b/arch/cris/arch-v10/drivers/i2c.c deleted file mode 100644 index ec35d62e8e63..000000000000 --- a/arch/cris/arch-v10/drivers/i2c.c +++ /dev/null @@ -1,699 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/*!*************************************************************************** -*! -*! FILE NAME : i2c.c -*! -*! DESCRIPTION: implements an interface for IIC/I2C, both directly from other -*! kernel modules (i2c_writereg/readreg) and from userspace using -*! ioctl()'s -*! -*! (C) Copyright 1999-2007 Axis Communications AB, LUND, SWEDEN -*! -*!***************************************************************************/ - -/****************** INCLUDE FILES SECTION ***********************************/ - -#include <linux/module.h> -#include <linux/sched.h> -#include <linux/errno.h> -#include <linux/kernel.h> -#include <linux/fs.h> -#include <linux/string.h> -#include <linux/init.h> - -#include <asm/etraxi2c.h> - -#include <arch/svinto.h> -#include <asm/io.h> -#include <asm/delay.h> -#include <arch/io_interface_mux.h> - -#include "i2c.h" - -/****************** I2C DEFINITION SECTION *************************/ - -#define D(x) - -#define I2C_MAJOR 123 /* LOCAL/EXPERIMENTAL */ -static const char i2c_name[] = "i2c"; - -#define CLOCK_LOW_TIME 8 -#define CLOCK_HIGH_TIME 8 -#define START_CONDITION_HOLD_TIME 8 -#define STOP_CONDITION_HOLD_TIME 8 -#define ENABLE_OUTPUT 0x01 -#define ENABLE_INPUT 0x00 -#define I2C_CLOCK_HIGH 1 -#define I2C_CLOCK_LOW 0 -#define I2C_DATA_HIGH 1 -#define I2C_DATA_LOW 0 - -#ifdef CONFIG_ETRAX_I2C_USES_PB_NOT_PB_I2C -/* Use PB and not PB_I2C */ -#ifndef CONFIG_ETRAX_I2C_DATA_PORT -#define CONFIG_ETRAX_I2C_DATA_PORT 0 -#endif -#ifndef CONFIG_ETRAX_I2C_CLK_PORT -#define CONFIG_ETRAX_I2C_CLK_PORT 1 -#endif - -#define SDABIT CONFIG_ETRAX_I2C_DATA_PORT -#define SCLBIT CONFIG_ETRAX_I2C_CLK_PORT -#define i2c_enable() -#define i2c_disable() - -/* enable or disable output-enable, to select output or input on the i2c bus */ - -#define i2c_dir_out() \ - REG_SHADOW_SET(R_PORT_PB_DIR, port_pb_dir_shadow, SDABIT, 1) -#define i2c_dir_in() \ - REG_SHADOW_SET(R_PORT_PB_DIR, port_pb_dir_shadow, SDABIT, 0) - -/* control the i2c clock and data signals */ - -#define i2c_clk(x) \ - REG_SHADOW_SET(R_PORT_PB_DATA, port_pb_data_shadow, SCLBIT, x) -#define i2c_data(x) \ - REG_SHADOW_SET(R_PORT_PB_DATA, port_pb_data_shadow, SDABIT, x) - -/* read a bit from the i2c interface */ - -#define i2c_getbit() (((*R_PORT_PB_READ & (1 << SDABIT))) >> SDABIT) - -#else -/* enable or disable the i2c interface */ - -#define i2c_enable() *R_PORT_PB_I2C = (port_pb_i2c_shadow |= IO_MASK(R_PORT_PB_I2C, i2c_en)) -#define i2c_disable() *R_PORT_PB_I2C = (port_pb_i2c_shadow &= ~IO_MASK(R_PORT_PB_I2C, i2c_en)) - -/* enable or disable output-enable, to select output or input on the i2c bus */ - -#define i2c_dir_out() \ - *R_PORT_PB_I2C = (port_pb_i2c_shadow &= ~IO_MASK(R_PORT_PB_I2C, i2c_oe_)); \ - REG_SHADOW_SET(R_PORT_PB_DIR, port_pb_dir_shadow, 0, 1); -#define i2c_dir_in() \ - *R_PORT_PB_I2C = (port_pb_i2c_shadow |= IO_MASK(R_PORT_PB_I2C, i2c_oe_)); \ - REG_SHADOW_SET(R_PORT_PB_DIR, port_pb_dir_shadow, 0, 0); - -/* control the i2c clock and data signals */ - -#define i2c_clk(x) \ - *R_PORT_PB_I2C = (port_pb_i2c_shadow = (port_pb_i2c_shadow & \ - ~IO_MASK(R_PORT_PB_I2C, i2c_clk)) | IO_FIELD(R_PORT_PB_I2C, i2c_clk, (x))); \ - REG_SHADOW_SET(R_PORT_PB_DATA, port_pb_data_shadow, 1, x); - -#define i2c_data(x) \ - *R_PORT_PB_I2C = (port_pb_i2c_shadow = (port_pb_i2c_shadow & \ - ~IO_MASK(R_PORT_PB_I2C, i2c_d)) | IO_FIELD(R_PORT_PB_I2C, i2c_d, (x))); \ - REG_SHADOW_SET(R_PORT_PB_DATA, port_pb_data_shadow, 0, x); - -/* read a bit from the i2c interface */ - -#define i2c_getbit() (*R_PORT_PB_READ & 0x1) -#endif - -/* use the kernels delay routine */ - -#define i2c_delay(usecs) udelay(usecs) - -static DEFINE_SPINLOCK(i2c_lock); /* Protect directions etc */ - -/****************** FUNCTION DEFINITION SECTION *************************/ - - -/* generate i2c start condition */ - -void -i2c_start(void) -{ - /* - * SCL=1 SDA=1 - */ - i2c_dir_out(); - i2c_delay(CLOCK_HIGH_TIME/6); - i2c_data(I2C_DATA_HIGH); - i2c_clk(I2C_CLOCK_HIGH); - i2c_delay(CLOCK_HIGH_TIME); - /* - * SCL=1 SDA=0 - */ - i2c_data(I2C_DATA_LOW); - i2c_delay(START_CONDITION_HOLD_TIME); - /* - * SCL=0 SDA=0 - */ - i2c_clk(I2C_CLOCK_LOW); - i2c_delay(CLOCK_LOW_TIME); -} - -/* generate i2c stop condition */ - -void -i2c_stop(void) -{ - i2c_dir_out(); - - /* - * SCL=0 SDA=0 - */ - i2c_clk(I2C_CLOCK_LOW); - i2c_data(I2C_DATA_LOW); - i2c_delay(CLOCK_LOW_TIME*2); - /* - * SCL=1 SDA=0 - */ - i2c_clk(I2C_CLOCK_HIGH); - i2c_delay(CLOCK_HIGH_TIME*2); - /* - * SCL=1 SDA=1 - */ - i2c_data(I2C_DATA_HIGH); - i2c_delay(STOP_CONDITION_HOLD_TIME); - - i2c_dir_in(); -} - -/* write a byte to the i2c interface */ - -void -i2c_outbyte(unsigned char x) -{ - int i; - - i2c_dir_out(); - - for (i = 0; i < 8; i++) { - if (x & 0x80) { - i2c_data(I2C_DATA_HIGH); - } else { - i2c_data(I2C_DATA_LOW); - } - - i2c_delay(CLOCK_LOW_TIME/2); - i2c_clk(I2C_CLOCK_HIGH); - i2c_delay(CLOCK_HIGH_TIME); - i2c_clk(I2C_CLOCK_LOW); - i2c_delay(CLOCK_LOW_TIME/2); - x <<= 1; - } - i2c_data(I2C_DATA_LOW); - i2c_delay(CLOCK_LOW_TIME/2); - - /* - * enable input - */ - i2c_dir_in(); -} - -/* read a byte from the i2c interface */ - -unsigned char -i2c_inbyte(void) -{ - unsigned char aBitByte = 0; - int i; - - /* Switch off I2C to get bit */ - i2c_disable(); - i2c_dir_in(); - i2c_delay(CLOCK_HIGH_TIME/2); - - /* Get bit */ - aBitByte |= i2c_getbit(); - - /* Enable I2C */ - i2c_enable(); - i2c_delay(CLOCK_LOW_TIME/2); - - for (i = 1; i < 8; i++) { - aBitByte <<= 1; - /* Clock pulse */ - i2c_clk(I2C_CLOCK_HIGH); - i2c_delay(CLOCK_HIGH_TIME); - i2c_clk(I2C_CLOCK_LOW); - i2c_delay(CLOCK_LOW_TIME); - - /* Switch off I2C to get bit */ - i2c_disable(); - i2c_dir_in(); - i2c_delay(CLOCK_HIGH_TIME/2); - - /* Get bit */ - aBitByte |= i2c_getbit(); - - /* Enable I2C */ - i2c_enable(); - i2c_delay(CLOCK_LOW_TIME/2); - } - i2c_clk(I2C_CLOCK_HIGH); - i2c_delay(CLOCK_HIGH_TIME); - - /* - * we leave the clock low, getbyte is usually followed - * by sendack/nack, they assume the clock to be low - */ - i2c_clk(I2C_CLOCK_LOW); - return aBitByte; -} - -/*#--------------------------------------------------------------------------- -*# -*# FUNCTION NAME: i2c_getack -*# -*# DESCRIPTION : checks if ack was received from ic2 -*# -*#--------------------------------------------------------------------------*/ - -int -i2c_getack(void) -{ - int ack = 1; - /* - * enable output - */ - i2c_dir_out(); - /* - * Release data bus by setting - * data high - */ - i2c_data(I2C_DATA_HIGH); - /* - * enable input - */ - i2c_dir_in(); - i2c_delay(CLOCK_HIGH_TIME/4); - /* - * generate ACK clock pulse - */ - i2c_clk(I2C_CLOCK_HIGH); - /* - * Use PORT PB instead of I2C - * for input. (I2C not working) - */ - i2c_clk(1); - i2c_data(1); - /* - * switch off I2C - */ - i2c_data(1); - i2c_disable(); - i2c_dir_in(); - /* - * now wait for ack - */ - i2c_delay(CLOCK_HIGH_TIME/2); - /* - * check for ack - */ - if(i2c_getbit()) - ack = 0; - i2c_delay(CLOCK_HIGH_TIME/2); - if(!ack){ - if(!i2c_getbit()) /* receiver pulld SDA low */ - ack = 1; - i2c_delay(CLOCK_HIGH_TIME/2); - } - - /* - * our clock is high now, make sure data is low - * before we enable our output. If we keep data high - * and enable output, we would generate a stop condition. - */ - i2c_data(I2C_DATA_LOW); - - /* - * end clock pulse - */ - i2c_enable(); - i2c_dir_out(); - i2c_clk(I2C_CLOCK_LOW); - i2c_delay(CLOCK_HIGH_TIME/4); - /* - * enable output - */ - i2c_dir_out(); - /* - * remove ACK clock pulse - */ - i2c_data(I2C_DATA_HIGH); - i2c_delay(CLOCK_LOW_TIME/2); - return ack; -} - -/*#--------------------------------------------------------------------------- -*# -*# FUNCTION NAME: I2C::sendAck -*# -*# DESCRIPTION : Send ACK on received data -*# -*#--------------------------------------------------------------------------*/ -void -i2c_sendack(void) -{ - /* - * enable output - */ - i2c_delay(CLOCK_LOW_TIME); - i2c_dir_out(); - /* - * set ack pulse high - */ - i2c_data(I2C_DATA_LOW); - /* - * generate clock pulse - */ - i2c_delay(CLOCK_HIGH_TIME/6); - i2c_clk(I2C_CLOCK_HIGH); - i2c_delay(CLOCK_HIGH_TIME); - i2c_clk(I2C_CLOCK_LOW); - i2c_delay(CLOCK_LOW_TIME/6); - /* - * reset data out - */ - i2c_data(I2C_DATA_HIGH); - i2c_delay(CLOCK_LOW_TIME); - - i2c_dir_in(); -} - -/*#--------------------------------------------------------------------------- -*# -*# FUNCTION NAME: i2c_sendnack -*# -*# DESCRIPTION : Sends NACK on received data -*# -*#--------------------------------------------------------------------------*/ -void -i2c_sendnack(void) -{ - /* - * enable output - */ - i2c_delay(CLOCK_LOW_TIME); - i2c_dir_out(); - /* - * set data high - */ - i2c_data(I2C_DATA_HIGH); - /* - * generate clock pulse - */ - i2c_delay(CLOCK_HIGH_TIME/6); - i2c_clk(I2C_CLOCK_HIGH); - i2c_delay(CLOCK_HIGH_TIME); - i2c_clk(I2C_CLOCK_LOW); - i2c_delay(CLOCK_LOW_TIME); - - i2c_dir_in(); -} - -/*#--------------------------------------------------------------------------- -*# -*# FUNCTION NAME: i2c_writereg -*# -*# DESCRIPTION : Writes a value to an I2C device -*# -*#--------------------------------------------------------------------------*/ -int -i2c_writereg(unsigned char theSlave, unsigned char theReg, - unsigned char theValue) -{ - int error, cntr = 3; - unsigned long flags; - - spin_lock(&i2c_lock); - - do { - error = 0; - /* - * we don't like to be interrupted - */ - local_irq_save(flags); - - i2c_start(); - /* - * send slave address - */ - i2c_outbyte((theSlave & 0xfe)); - /* - * wait for ack - */ - if(!i2c_getack()) - error = 1; - /* - * now select register - */ - i2c_dir_out(); - i2c_outbyte(theReg); - /* - * now it's time to wait for ack - */ - if(!i2c_getack()) - error |= 2; - /* - * send register register data - */ - i2c_outbyte(theValue); - /* - * now it's time to wait for ack - */ - if(!i2c_getack()) - error |= 4; - /* - * end byte stream - */ - i2c_stop(); - /* - * enable interrupt again - */ - local_irq_restore(flags); - - } while(error && cntr--); - - i2c_delay(CLOCK_LOW_TIME); - - spin_unlock(&i2c_lock); - - return -error; -} - -/*#--------------------------------------------------------------------------- -*# -*# FUNCTION NAME: i2c_readreg -*# -*# DESCRIPTION : Reads a value from the decoder registers. -*# -*#--------------------------------------------------------------------------*/ -unsigned char -i2c_readreg(unsigned char theSlave, unsigned char theReg) -{ - unsigned char b = 0; - int error, cntr = 3; - unsigned long flags; - - spin_lock(&i2c_lock); - - do { - error = 0; - /* - * we don't like to be interrupted - */ - local_irq_save(flags); - /* - * generate start condition - */ - i2c_start(); - - /* - * send slave address - */ - i2c_outbyte((theSlave & 0xfe)); - /* - * wait for ack - */ - if(!i2c_getack()) - error = 1; - /* - * now select register - */ - i2c_dir_out(); - i2c_outbyte(theReg); - /* - * now it's time to wait for ack - */ - if(!i2c_getack()) - error = 1; - /* - * repeat start condition - */ - i2c_delay(CLOCK_LOW_TIME); - i2c_start(); - /* - * send slave address - */ - i2c_outbyte(theSlave | 0x01); - /* - * wait for ack - */ - if(!i2c_getack()) - error = 1; - /* - * fetch register - */ - b = i2c_inbyte(); - /* - * last received byte needs to be nacked - * instead of acked - */ - i2c_sendnack(); - /* - * end sequence - */ - i2c_stop(); - /* - * enable interrupt again - */ - local_irq_restore(flags); - - } while(error && cntr--); - - spin_unlock(&i2c_lock); - - return b; -} - -static int -i2c_open(struct inode *inode, struct file *filp) -{ - return 0; -} - -static int -i2c_release(struct inode *inode, struct file *filp) -{ - return 0; -} - -/* Main device API. ioctl's to write or read to/from i2c registers. - */ - -static long i2c_ioctl(struct file *file, unsigned int cmd, unsigned long arg) -{ - if(_IOC_TYPE(cmd) != ETRAXI2C_IOCTYPE) { - return -EINVAL; - } - - switch (_IOC_NR(cmd)) { - case I2C_WRITEREG: - /* write to an i2c slave */ - D(printk(KERN_DEBUG "i2cw %d %d %d\n", - I2C_ARGSLAVE(arg), - I2C_ARGREG(arg), - I2C_ARGVALUE(arg))); - - return i2c_writereg(I2C_ARGSLAVE(arg), - I2C_ARGREG(arg), - I2C_ARGVALUE(arg)); - case I2C_READREG: - { - unsigned char val; - /* read from an i2c slave */ - D(printk(KERN_DEBUG "i2cr %d %d ", - I2C_ARGSLAVE(arg), - I2C_ARGREG(arg))); - val = i2c_readreg(I2C_ARGSLAVE(arg), I2C_ARGREG(arg)); - D(printk(KERN_DEBUG "= %d\n", val)); - return val; - } - default: - return -EINVAL; - - } - return 0; -} - -static const struct file_operations i2c_fops = { - .owner = THIS_MODULE, - .unlocked_ioctl = i2c_ioctl, - .open = i2c_open, - .release = i2c_release, - .llseek = noop_llseek, -}; - -int __init -i2c_init(void) -{ - static int res = 0; - static int first = 1; - - if (!first) { - return res; - } - first = 0; - - /* Setup and enable the Port B I2C interface */ - -#ifndef CONFIG_ETRAX_I2C_USES_PB_NOT_PB_I2C - if ((res = cris_request_io_interface(if_i2c, "I2C"))) { - printk(KERN_CRIT "i2c_init: Failed to get IO interface\n"); - return res; - } - - *R_PORT_PB_I2C = port_pb_i2c_shadow |= - IO_STATE(R_PORT_PB_I2C, i2c_en, on) | - IO_FIELD(R_PORT_PB_I2C, i2c_d, 1) | - IO_FIELD(R_PORT_PB_I2C, i2c_clk, 1) | - IO_STATE(R_PORT_PB_I2C, i2c_oe_, enable); - - port_pb_dir_shadow &= ~IO_MASK(R_PORT_PB_DIR, dir0); - port_pb_dir_shadow &= ~IO_MASK(R_PORT_PB_DIR, dir1); - - *R_PORT_PB_DIR = (port_pb_dir_shadow |= - IO_STATE(R_PORT_PB_DIR, dir0, input) | - IO_STATE(R_PORT_PB_DIR, dir1, output)); -#else - if ((res = cris_io_interface_allocate_pins(if_i2c, - 'b', - CONFIG_ETRAX_I2C_DATA_PORT, - CONFIG_ETRAX_I2C_DATA_PORT))) { - printk(KERN_WARNING "i2c_init: Failed to get IO pin for I2C data port\n"); - return res; - } else if ((res = cris_io_interface_allocate_pins(if_i2c, - 'b', - CONFIG_ETRAX_I2C_CLK_PORT, - CONFIG_ETRAX_I2C_CLK_PORT))) { - cris_io_interface_free_pins(if_i2c, - 'b', - CONFIG_ETRAX_I2C_DATA_PORT, - CONFIG_ETRAX_I2C_DATA_PORT); - printk(KERN_WARNING "i2c_init: Failed to get IO pin for I2C clk port\n"); - } -#endif - - return res; -} - -static int __init -i2c_register(void) -{ - int res; - - res = i2c_init(); - if (res < 0) - return res; - res = register_chrdev(I2C_MAJOR, i2c_name, &i2c_fops); - if(res < 0) { - printk(KERN_ERR "i2c: couldn't get a major number.\n"); - return res; - } - - printk(KERN_INFO "I2C driver v2.2, (c) 1999-2004 Axis Communications AB\n"); - - return 0; -} - -/* this makes sure that i2c_register is called during boot */ - -module_init(i2c_register); - -/****************** END OF FILE i2c.c ********************************/ |