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nuttx/arch/arm/src/lpc2378/lpc23xx_i2c.c

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/*******************************************************************************
* arch/arm/src/lpc2378/lpc23xx_i2c.c
*
* Copyright (C) 2013 Li Zhuoyi. All rights reserved.
* Author: Li Zhuoyi <lzyy.cn@gmail.com>
*
* Derived from arch/arm/src/lpc17xx/lpc23xx_i2c.c
*
* Copyright (C) 2011 Li Zhuoyi. All rights reserved.
* Author: Li Zhuoyi <lzyy.cn@gmail.com>
* History: 0.1 2011-08-20 initial version
*
* Derived from arch/arm/src/lpc31xx/lpc31_i2c.c
*
* Author: David Hewson
*
* Copyright (C) 2010-2011, 2014 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
*******************************************************************************/
/*******************************************************************************
* Included Files
*******************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <stdint.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/arch.h>
#include <nuttx/wdog.h>
#include <nuttx/i2c.h>
#include <arch/irq.h>
#include <arch/board/board.h>
#include "chip.h"
#include "up_arch.h"
#include "up_internal.h"
#include "lpc23xx_pinsel.h"
#include "lpc23xx_scb.h"
#include "lpc23xx_i2c.h"
#if defined(CONFIG_LPC2378_I2C0) || defined(CONFIG_LPC2378_I2C1) || \
defined(CONFIG_LPC2378_I2C2)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#ifndef GPIO_I2C1_SCL
# define GPIO_I2C1_SCL GPIO_I2C1_SCL_1
# define GPIO_I2C1_SDA GPIO_I2C1_SDA_1
#endif
#ifndef CONFIG_I2C0_FREQ
# define CONFIG_I2C0_FREQ 100000
#endif
#ifndef CONFIG_I2C1_FREQ
# define CONFIG_I2C1_FREQ 100000
#endif
#ifndef CONFIG_I2C2_FREQ
# define CONFIG_I2C2_FREQ 100000
#endif
#define I2C_TIMEOUT ((500 * CLK_TCK) / 1000) /* 500 mS */
/****************************************************************************
* Private Data
****************************************************************************/
struct lpc23xx_i2cdev_s
{
struct i2c_dev_s dev; /* Generic I2C device */
struct i2c_msg_s msg; /* a single message for legacy read/write */
unsigned int base; /* Base address of registers */
uint16_t irqid; /* IRQ for this device */
sem_t mutex; /* Only one thread can access at a time */
sem_t wait; /* Place to wait for state machine completion */
volatile uint8_t state; /* State of state machine */
WDOG_ID timeout; /* watchdog to timeout when bus hung */
uint16_t wrcnt; /* number of bytes sent to tx fifo */
uint16_t rdcnt; /* number of bytes read from rx fifo */
};
static struct lpc23xx_i2cdev_s i2cdevices[3];
/****************************************************************************
* Private Functions
****************************************************************************/
static int i2c_start (struct lpc23xx_i2cdev_s *priv);
static void i2c_stop (struct lpc23xx_i2cdev_s *priv);
static int i2c_interrupt (int irq, FAR void *context);
static void i2c_timeout (int argc, uint32_t arg, ...);
/****************************************************************************
* I2C device operations
****************************************************************************/
static uint32_t i2c_setfrequency(FAR struct i2c_dev_s *dev, uint32_t frequency);
static int i2c_setaddress(FAR struct i2c_dev_s *dev, int addr, int nbits);
static int i2c_write(FAR struct i2c_dev_s *dev, const uint8_t *buffer, int buflen);
static int i2c_read(FAR struct i2c_dev_s *dev, uint8_t *buffer, int buflen);
static int i2c_transfer(FAR struct i2c_dev_s *dev, FAR struct i2c_msg_s *msgs, int count);
struct i2c_ops_s lpc23xx_i2c_ops =
{
.setfrequency = i2c_setfrequency,
.setaddress = i2c_setaddress,
.write = i2c_write,
.read = i2c_read,
#ifdef CONFIG_I2C_TRANSFER
.transfer = i2c_transfer
#endif
};
/*******************************************************************************
* Name: lpc23xx_i2c_setfrequency
*
* Description:
* Set the frequence for the next transfer
*
*******************************************************************************/
static uint32_t i2c_setfrequency(FAR struct i2c_dev_s *dev, uint32_t frequency)
{
struct lpc23xx_i2cdev_s *priv = (struct lpc23xx_i2cdev_s *) dev;
if (frequency > 100000)
{
/* Asymetric per 400Khz I2C spec */
putreg32(LPC23XX_CCLK / (83 + 47) * 47 / frequency,
priv->base + I2C_SCLH_OFFSET);
putreg32(LPC23XX_CCLK / (83 + 47) * 83 / frequency,
priv->base + I2C_SCLL_OFFSET);
}
else
{
/* 50/50 mark space ratio */
putreg32(LPC23XX_CCLK / 100 * 50 / frequency,
priv->base + I2C_SCLH_OFFSET);
putreg32(LPC23XX_CCLK / 100 * 50 / frequency,
priv->base + I2C_SCLL_OFFSET);
}
/* FIXME: This function should return the actual selected frequency */
return frequency;
}
/*******************************************************************************
* Name: lpc23xx_i2c_setaddress
*
* Description:
* Set the I2C slave address for a subsequent read/write
*
*******************************************************************************/
static int i2c_setaddress(FAR struct i2c_dev_s *dev, int addr, int nbits)
{
struct lpc23xx_i2cdev_s *priv = (struct lpc23xx_i2cdev_s *) dev;
DEBUGASSERT(dev != NULL);
DEBUGASSERT(nbits == 7);
priv->msg.addr = addr << 1;
priv->msg.flags = 0 ;
return OK;
}
/*******************************************************************************
* Name: lpc23xx_i2c_write
*
* Description:
* Send a block of data on I2C using the previously selected I2C
* frequency and slave address.
*
*******************************************************************************/
static int i2c_write(FAR struct i2c_dev_s *dev, const uint8_t *buffer, int buflen)
{
struct lpc23xx_i2cdev_s *priv = (struct lpc23xx_i2cdev_s *) dev;
int ret;
DEBUGASSERT (dev != NULL);
priv->wrcnt = 0;
priv->rdcnt = 0;
priv->msg.addr &= ~0x01;
priv->msg.buffer = (uint8_t*)buffer;
priv->msg.length = buflen;
ret = i2c_start (priv);
return ret >0 ? OK : -ETIMEDOUT;
}
/*******************************************************************************
* Name: lpc23xx_i2c_read
*
* Description:
* Receive a block of data on I2C using the previously selected I2C
* frequency and slave address.
*
*******************************************************************************/
static int i2c_read(FAR struct i2c_dev_s *dev, uint8_t *buffer, int buflen)
{
struct lpc23xx_i2cdev_s *priv = (struct lpc23xx_i2cdev_s *) dev;
int ret;
DEBUGASSERT (dev != NULL);
priv->wrcnt = 0;
priv->rdcnt = 0;
priv->msg.addr |= 0x01;
priv->msg.buffer = buffer;
priv->msg.length = buflen;
ret = i2c_start(priv);
return ret > 0 ? OK : -ETIMEDOUT;
}
/*******************************************************************************
* Name: i2c_start
*
* Description:
* Perform a I2C transfer start
*
*******************************************************************************/
static int i2c_start (struct lpc23xx_i2cdev_s *priv)
{
int ret = -1;
sem_wait (&priv->mutex);
irqstate_t flags = irqsave();
putreg32(I2C_CONCLR_STAC | I2C_CONCLR_SIC, priv->base + I2C_CONCLR_OFFSET);
putreg32(I2C_CONSET_STA, priv->base + I2C_CONSET_OFFSET);
irqrestore (flags);
wd_start(priv->timeout, I2C_TIMEOUT, i2c_timeout, 1, (uint32_t)priv);
sem_wait(&priv->wait);
wd_cancel(priv->timeout);
sem_post(&priv->mutex);
if (priv-> state == 0x18 || priv->state == 0x28)
{
ret=priv->wrcnt;
}
else if (priv-> state == 0x50 || priv->state == 0x58)
{
ret=priv->rdcnt;
}
return ret;
}
/*******************************************************************************
* Name: i2c_stop
*
* Description:
* Perform a I2C transfer stop
*
*******************************************************************************/
static void i2c_stop (struct lpc23xx_i2cdev_s *priv)
{
if (priv->state != 0x38)
{
putreg32(I2C_CONSET_STO | I2C_CONSET_AA, priv->base + I2C_CONSET_OFFSET);
}
sem_post (&priv->wait);
}
/*******************************************************************************
* Name: i2c_timeout
*
* Description:
* Watchdog timer for timeout of I2C operation
*
*******************************************************************************/
static void i2c_timeout (int argc, uint32_t arg, ...)
{
struct lpc23xx_i2cdev_s *priv = (struct lpc23xx_i2cdev_s *)arg;
irqstate_t flags = irqsave();
priv->state = 0xff;
sem_post(&priv->wait);
irqrestore(flags);
}
/*******************************************************************************
* Name: i2c_interrupt
*
* Description:
* The I2C Interrupt Handler
*
*******************************************************************************/
static int i2c_interrupt (int irq, FAR void *context)
{
struct lpc23xx_i2cdev_s *priv;
#ifdef CONFIG_LPC2378_I2C0
if (irq == I2C0_IRQ)
{
priv = &i2cdevices[0];
}
else
#endif
#ifdef CONFIG_LPC2378_I2C1
if (irq == I2C1_IRQ)
{
priv = &i2cdevices[1];
}
else
#endif
#ifdef CONFIG_LPC2378_I2C2
if (irq == I2C2_IRQ)
{
priv = &i2cdevices[2];
}
else
#endif
{
PANIC();
}
/* Reference UM10360 19.10.5 */
uint32_t state = getreg32(priv->base + I2C_STAT_OFFSET);
putreg32(I2C_CONCLR_SIC, priv->base + I2C_CONCLR_OFFSET);
priv->state = state;
state &= 0xf8;
switch (state)
{
case 0x00: /* Bus Error */
case 0x20:
case 0x30:
case 0x38:
case 0x48:
i2c_stop(priv);
break;
case 0x08: /* START */
case 0x10: /* Repeated START */
putreg32(priv->msg.addr, priv->base + I2C_DAT_OFFSET);
putreg32(I2C_CONCLR_STAC, priv->base + I2C_CONCLR_OFFSET);
break;
case 0x18:
priv->wrcnt=0;
putreg32(priv->msg.buffer[0], priv->base + I2C_DAT_OFFSET);
break;
case 0x28:
priv->wrcnt++;
if (priv->wrcnt<priv->msg.length)
{
putreg32(priv->msg.buffer[priv->wrcnt],priv->base+I2C_DAT_OFFSET);
}
else
{
i2c_stop(priv);
}
break;
case 0x40:
priv->rdcnt = -1;
putreg32(I2C_CONSET_AA, priv->base + I2C_CONSET_OFFSET);
break;
case 0x50:
priv->rdcnt++;
if (priv->rdcnt<priv->msg.length)
{
priv->msg.buffer[priv->rdcnt] = getreg32(priv->base + I2C_DAT_OFFSET);
}
if (priv->rdcnt>=priv->msg.length-1)
{
putreg32(I2C_CONCLR_AAC | I2C_CONCLR_SIC, priv->base + I2C_CONCLR_OFFSET);
}
break;
case 0x58:
i2c_stop(priv);
break;
default:
i2c_stop(priv);
break;
}
return OK;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/*******************************************************************************
* Name: up_i2cinitialize
*
* Description:
* Initialise an I2C device
*
*******************************************************************************/
struct i2c_dev_s *up_i2cinitialize(int port)
{
struct lpc23xx_i2cdev_s *priv;
irqstate_t flags;
uint32_t regval;
if (port > 2)
{
dbg("lpc I2C Only support 0,1,2\n");
return NULL;
}
flags = irqsave();
priv = &i2cdevices[port];
#ifdef CONFIG_LPC2378_I2C0
if (port == 0)
{
priv = (FAR struct lpc23xx_i2cdev_s *)&i2cdevices[0];
priv->base = I2C0_BASE_ADDR;
priv->irqid = I2C0_IRQ;
regval = getreg32(LPC23XX_SCB_BASE + SCB_PCONP_OFFSET);
regval |= PCI2C0;
putreg32(regval, LPC23XX_SCB_BASE + SCB_PCONP_OFFSET);
regval = getreg32(LPC23XX_SCB_BASE + SCB_PCLKSEL0_OFFSET);
regval &= ~I2C0_PCLKSEL_MASK;
regval |= I2C0_PCLKSEL;
putreg32(regval, LPC23XX_SCB_BASE + SCB_PCLKSEL0_OFFSET);
regval = getreg32(LPC23XX_PINSEL1);
regval &= ~I2C0_PINSEL_MASK ;
regval |= I2C0_PINSEL;
putreg32(regval, LPC23XX_PINSEL1);
putreg32(LPC23XX_CCLK / CONFIG_I2C0_FREQ / 2,
priv->base + I2C_SCLH_OFFSET);
putreg32(LPC23XX_CCLK / CONFIG_I2C0_FREQ / 2,
priv->base + I2C_SCLL_OFFSET);
}
else
#endif
#ifdef CONFIG_LPC2378_I2C1
if (port == 1)
{
priv= (FAR struct lpc23xx_i2cdev_s *)&i2cdevices[1];
priv->base = I2C1_BASE_ADDR;
priv->irqid = I2C1_IRQ;
regval = getreg32(LPC23XX_SCB_BASE + SCB_PCONP_OFFSET);
regval |= PCI2C1;
putreg32(regval, LPC23XX_SCB_BASE + SCB_PCONP_OFFSET);
regval = getreg32(LPC23XX_SCB_BASE + SCB_PCLKSEL1_OFFSET);
regval &= ~I2C1_PCLKSEL_MASK;
regval |= I2C1_PCLKSEL;
putreg32(regval, LPC23XX_SCB_BASE + SCB_PCLKSEL1_OFFSET);
regval = getreg32(LPC23XX_PINSEL0);
regval &= ~I2C1_PINSEL_MASK ;
regval |= I2C1_PINSEL;
putreg32(regval, LPC23XX_PINSEL0);
putreg32(LPC23XX_CCLK / CONFIG_I2C1_FREQ / 2,
priv->base + I2C_SCLH_OFFSET);
putreg32(LPC23XX_CCLK / CONFIG_I2C1_FREQ / 2,
priv->base + I2C_SCLL_OFFSET);
}
else
#endif
#ifdef CONFIG_LPC2378_I2C2
if (port == 2)
{
priv= (FAR struct lpc23xx_i2cdev_s *)&i2cdevices[2];
priv->base = I2C2_BASE_ADDR;
priv->irqid = I2C2_IRQ;
regval = getreg32(LPC23XX_SCB_BASE + SCB_PCONP_OFFSET);
regval |= PCI2C2;
putreg32(regval, LPC23XX_SCB_BASE + SCB_PCONP_OFFSET);
regval = getreg32(LPC23XX_SCB_BASE + SCB_PCLKSEL1_OFFSET);
regval &= ~I2C2_PCLKSEL_MASK;
regval |= I2C2_PCLKSEL;
putreg32(regval, LPC23XX_SCB_BASE + SCB_PCLKSEL1_OFFSET);
regval = getreg32(LPC23XX_PINSEL0);
regval &= ~I2C2_PINSEL_MASK ;
regval |= I2C2_PINSEL;
putreg32(regval, LPC23XX_PINSEL0);
putreg32(LPC23XX_CCLK / CONFIG_I2C2_FREQ / 2,
priv->base + I2C_SCLH_OFFSET);
putreg32(LPC23XX_CCLK / CONFIG_I2C2_FREQ / 2,
priv->base + I2C_SCLL_OFFSET);
}
else
#endif
{
irqrestore(flags);
return NULL;
}
putreg32(I2C_CONSET_I2EN,priv->base+I2C_CONSET_OFFSET);
sem_init (&priv->mutex, 0, 1);
sem_init (&priv->wait, 0, 0);
/* Allocate a watchdog timer */
priv->timeout = wd_create();
DEBUGASSERT(priv->timeout != 0);
/* Attach Interrupt Handler */
irq_attach (priv->irqid, i2c_interrupt);
/* Enable Interrupt Handler */
up_enable_irq(priv->irqid);
/* Install our operations */
priv->dev.ops = &lpc23xx_i2c_ops;
irqrestore(flags);
return &priv->dev;
}
/*******************************************************************************
* Name: up_i2cuninitalize
*
* Description:
* Uninitialise an I2C device
*
*******************************************************************************/
int up_i2cuninitialize(FAR struct i2c_dev_s * dev)
{
struct lpc23xx_i2cdev_s *priv = (struct lpc23xx_i2cdev_s *)dev;
putreg32(I2C_CONCLRT_I2ENC,priv->base+I2C_CONCLR_OFFSET);
up_disable_irq(priv->irqid);
irq_detach(priv->irqid);
return OK;
}
#endif
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