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nuttx/arch/arm/src/lpc17xx_40xx/lpc17_40_i2c.c
Xiang Xiao 6a3c2aded6 Fix wait loop and void cast (#24) 
* Simplify EINTR/ECANCEL error handling

1. Add semaphore uninterruptible wait function
2 .Replace semaphore wait loop with a single uninterruptible wait
3. Replace all sem_xxx to nxsem_xxx

* Unify the void cast usage

1. Remove void cast for function because many place ignore the returned value witout cast
2. Replace void cast for variable with UNUSED macro
2020-01-02 10:54:43 -06:00

689 lines
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/****************************************************************************
* arch/arm/src/lpc17xx_40xx/lpc17_40_i2c.c
*
* Copyright (C) 2012, 2014-2016, 2019 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Copyright (C) 2011 Li Zhuoyi. All rights reserved.
* Author: Li Zhuoyi <lzyy.cn@gmail.com> (Original author)
*
* Derived from arch/arm/src/lpc31xx/lpc31_i2c.c
*
* Author: David Hewson
*
* Copyright (C) 2010-2011 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/semaphore.h>
#include <nuttx/i2c/i2c_master.h>
#include <nuttx/irq.h>
#include <arch/board/board.h>
#include "chip.h"
#include "up_arch.h"
#include "up_internal.h"
#include "chip.h"
#include "hardware/lpc17_40_syscon.h"
#include "lpc17_40_gpio.h"
#include "lpc17_40_i2c.h"
#if defined(CONFIG_LPC17_40_I2C0) || defined(CONFIG_LPC17_40_I2C1) || defined(CONFIG_LPC17_40_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_LPC17_40_I2C0_FREQUENCY
# define CONFIG_LPC17_40_I2C0_FREQUENCY 100000
#endif
#ifndef CONFIG_LPC17_40_I2C1_FREQUENCY
# define CONFIG_LPC17_40_I2C1_FREQUENCY 100000
#endif
#ifndef CONFIG_LPC17_40_I2C2_FREQUENCY
# define CONFIG_LPC17_40_I2C2_FREQUENCY 100000
#endif
#define LPC17_40_I2C1_FREQUENCY 400000
/****************************************************************************
* Private Types
****************************************************************************/
struct lpc17_40_i2cdev_s
{
struct i2c_master_s dev; /* Generic I2C device */
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 */
uint32_t frequency; /* Current I2C frequency */
struct i2c_msg_s *msgs; /* remaining transfers - first one is in progress */
unsigned int nmsg; /* number of transfer remaining */
uint16_t wrcnt; /* number of bytes sent to tx fifo */
uint16_t rdcnt; /* number of bytes read from rx fifo */
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static int lpc17_40_i2c_start(struct lpc17_40_i2cdev_s *priv);
static void lpc17_40_i2c_stop(struct lpc17_40_i2cdev_s *priv);
static int lpc17_40_i2c_interrupt(int irq, FAR void *context, void *arg);
static void lpc17_40_i2c_timeout(int argc, uint32_t arg, ...);
static void lpc17_40_i2c_setfrequency(struct lpc17_40_i2cdev_s *priv,
uint32_t frequency);
static void lpc17_40_stopnext(struct lpc17_40_i2cdev_s *priv);
/* I2C device operations */
static int lpc17_40_i2c_transfer(FAR struct i2c_master_s *dev,
FAR struct i2c_msg_s *msgs, int count);
#ifdef CONFIG_I2C_RESET
static int lpc17_40_i2c_reset(FAR struct i2c_master_s * dev);
#endif
/****************************************************************************
* Private Data
****************************************************************************/
#ifdef CONFIG_LPC17_40_I2C0
static struct lpc17_40_i2cdev_s g_i2c0dev;
#endif
#ifdef CONFIG_LPC17_40_I2C1
static struct lpc17_40_i2cdev_s g_i2c1dev;
#endif
#ifdef CONFIG_LPC17_40_I2C2
static struct lpc17_40_i2cdev_s g_i2c2dev;
#endif
struct i2c_ops_s lpc17_40_i2c_ops =
{
.transfer = lpc17_40_i2c_transfer
#ifdef CONFIG_I2C_RESET
, .reset = lpc17_40_i2c_reset
#endif
};
/****************************************************************************
* Name: lpc17_40_i2c_setfrequency
*
* Description:
* Set the frequency for the next transfer
*
****************************************************************************/
static void lpc17_40_i2c_setfrequency(struct lpc17_40_i2cdev_s *priv,
uint32_t frequency)
{
if (frequency != priv->frequency)
{
if (frequency > 100000)
{
/* Asymetric per 400Khz I2C spec */
putreg32(LPC17_40_CCLK / (83 + 47) * 47 / frequency,
priv->base + LPC17_40_I2C_SCLH_OFFSET);
putreg32(LPC17_40_CCLK / (83 + 47) * 83 / frequency,
priv->base + LPC17_40_I2C_SCLL_OFFSET);
}
else
{
/* 50/50 mark space ratio */
putreg32(LPC17_40_CCLK / 100 * 50 / frequency,
priv->base + LPC17_40_I2C_SCLH_OFFSET);
putreg32(LPC17_40_CCLK / 100 * 50 / frequency,
priv->base + LPC17_40_I2C_SCLL_OFFSET);
}
priv->frequency = frequency;
}
}
/****************************************************************************
* Name: lpc17_40_i2c_start
*
* Description:
* Perform a I2C transfer start
*
****************************************************************************/
static int lpc17_40_i2c_start(struct lpc17_40_i2cdev_s *priv)
{
uint32_t total_len = 0;
uint32_t freq = 1000000;
uint32_t timeout;
int i;
putreg32(I2C_CONCLR_STAC | I2C_CONCLR_SIC,
priv->base + LPC17_40_I2C_CONCLR_OFFSET);
putreg32(I2C_CONSET_STA, priv->base + LPC17_40_I2C_CONSET_OFFSET);
/* Get the total transaction length and the minimum frequency */
for (i = 0; i < priv->nmsg; i++)
{
total_len += priv->msgs[i].length;
if (priv->msgs[i].frequency < freq)
{
freq = priv->msgs[i].frequency;
}
}
/* Calculate the approximate timeout */
timeout = ((total_len * (8000000 / CONFIG_USEC_PER_TICK)) / freq) + 1;
/* Initializes the I2C state machine to a known value */
priv->state = 0x00;
wd_start(priv->timeout, timeout, lpc17_40_i2c_timeout, 1,
(uint32_t)priv);
nxsem_wait(&priv->wait);
wd_cancel(priv->timeout);
return priv->nmsg;
}
/****************************************************************************
* Name: lpc17_40_i2c_stop
*
* Description:
* Perform a I2C transfer stop
*
****************************************************************************/
static void lpc17_40_i2c_stop(struct lpc17_40_i2cdev_s *priv)
{
if (priv->state != 0x38)
{
putreg32(I2C_CONSET_STO | I2C_CONSET_AA,
priv->base + LPC17_40_I2C_CONSET_OFFSET);
}
nxsem_post(&priv->wait);
}
/****************************************************************************
* Name: lpc17_40_i2c_timeout
*
* Description:
* Watchdog timer for timeout of I2C operation
*
****************************************************************************/
static void lpc17_40_i2c_timeout(int argc, uint32_t arg, ...)
{
struct lpc17_40_i2cdev_s *priv = (struct lpc17_40_i2cdev_s *)arg;
irqstate_t flags = enter_critical_section();
priv->state = 0xff;
nxsem_post(&priv->wait);
leave_critical_section(flags);
}
/****************************************************************************
* Name: lpc17_40_i2c_transfer
*
* Description:
* Perform a sequence of I2C transfers
*
****************************************************************************/
static int lpc17_40_i2c_transfer(FAR struct i2c_master_s *dev,
FAR struct i2c_msg_s *msgs, int count)
{
struct lpc17_40_i2cdev_s *priv = (struct lpc17_40_i2cdev_s *)dev;
int ret;
DEBUGASSERT(dev != NULL && msgs != NULL && count > 0);
/* Get exclusive access to the I2C bus */
nxsem_wait(&priv->mutex);
/* Set up for the transfer */
priv->wrcnt = 0;
priv->rdcnt = 0;
priv->msgs = msgs;
priv->nmsg = count;
/* Configure the I2C frequency.
* REVISIT: Note that the frequency is set only on the first message.
* This could be extended to support different transfer frequencies for
* each message segment.
*/
lpc17_40_i2c_setfrequency(priv, msgs->frequency);
/* Perform the transfer */
ret = lpc17_40_i2c_start(priv);
nxsem_post(&priv->mutex);
return ret;
}
/****************************************************************************
* Name: lpc17_40_stopnext
*
* Description:
* Check if we need to issue STOP at the next message
*
****************************************************************************/
static void lpc17_40_stopnext(struct lpc17_40_i2cdev_s *priv)
{
priv->nmsg--;
if (priv->nmsg > 0)
{
priv->msgs++;
/* Check if a restart condition should be issued */
if (priv->msgs->flags & I2C_M_NOSTART)
{
priv->wrcnt = 0;
/* Starts transmitting the data buffer of the next message without
* issuing a restart.
*/
putreg32(priv->msgs->buffer[priv->wrcnt],
priv->base + LPC17_40_I2C_DAT_OFFSET);
}
else
{
putreg32(I2C_CONSET_STA, priv->base + LPC17_40_I2C_CONSET_OFFSET);
}
}
else
{
lpc17_40_i2c_stop(priv);
}
}
/****************************************************************************
* Name: lpc17_40_i2c_interrupt
*
* Description:
* The I2C Interrupt Handler
*
****************************************************************************/
static int lpc17_40_i2c_interrupt(int irq, FAR void *context, void *arg)
{
struct lpc17_40_i2cdev_s *priv = (struct lpc17_40_i2cdev_s *)arg;
struct i2c_msg_s *msg;
uint32_t state;
DEBUGASSERT(priv != NULL);
/* Reference UM10360 19.10.5 */
state = getreg32(priv->base + LPC17_40_I2C_STAT_OFFSET);
msg = priv->msgs;
/* Checks if a timeout occurred */
if (priv->state == 0xff)
{
state = 0xff;
}
else
{
priv->state = state;
state &= 0xf8; /* state mask, only 0xX8 is possible */
}
switch (state)
{
case 0x08: /* A START condition has been transmitted. */
case 0x10: /* A Repeated START condition has been transmitted. */
/* Set address */
putreg32(((I2C_M_READ & msg->flags) == I2C_M_READ) ?
I2C_READADDR8(msg->addr) :
I2C_WRITEADDR8(msg->addr), priv->base + LPC17_40_I2C_DAT_OFFSET);
/* Clear start bit */
putreg32(I2C_CONCLR_STAC, priv->base + LPC17_40_I2C_CONCLR_OFFSET);
break;
/* Write cases */
case 0x18: /* SLA+W has been transmitted; ACK has been received */
priv->wrcnt = 0;
putreg32(msg->buffer[0], priv->base + LPC17_40_I2C_DAT_OFFSET); /* put first byte */
break;
case 0x28: /* Data byte in DAT has been transmitted; ACK has been received. */
priv->wrcnt++;
if (priv->wrcnt < msg->length)
{
putreg32(msg->buffer[priv->wrcnt], priv->base + LPC17_40_I2C_DAT_OFFSET); /* Put next byte */
}
else
{
lpc17_40_stopnext(priv);
}
break;
/* Read cases */
case 0x40: /* SLA+R has been transmitted; ACK has been received */
priv->rdcnt = 0;
if (msg->length > 1)
{
putreg32(I2C_CONSET_AA, priv->base + LPC17_40_I2C_CONSET_OFFSET); /* Set ACK next read */
}
else
{
putreg32(I2C_CONCLR_AAC, priv->base + LPC17_40_I2C_CONCLR_OFFSET); /* Do not ACK because only one byte */
}
break;
case 0x50: /* Data byte has been received; ACK has been returned. */
priv->rdcnt++;
msg->buffer[priv->rdcnt - 1] =
getreg32(priv->base + LPC17_40_I2C_BUFR_OFFSET);
if (priv->rdcnt >= (msg->length - 1))
{
putreg32(I2C_CONCLR_AAC, priv->base + LPC17_40_I2C_CONCLR_OFFSET); /* Do not ACK any more */
}
break;
case 0x58: /* Data byte has been received; NACK has been returned. */
msg->buffer[priv->rdcnt] =
getreg32(priv->base + LPC17_40_I2C_BUFR_OFFSET);
lpc17_40_stopnext(priv);
break;
default:
lpc17_40_i2c_stop(priv);
break;
}
putreg32(I2C_CONCLR_SIC, priv->base + LPC17_40_I2C_CONCLR_OFFSET); /* clear interrupt */
return OK;
}
/****************************************************************************
* Name: lpc17_40_i2c_reset
*
* Description:
* Perform an I2C bus reset in an attempt to break loose stuck I2C devices.
*
* Input Parameters:
* dev - Device-specific state data
*
* Returned Value:
* Zero (OK) on success; a negated errno value on failure.
*
****************************************************************************/
#ifdef CONFIG_I2C_RESET
static int lpc17_40_i2c_reset(FAR struct i2c_master_s * dev)
{
return OK;
}
#endif /* CONFIG_I2C_RESET */
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: lpc17_40_i2cbus_initialize
*
* Description:
* Initialise an I2C device
*
****************************************************************************/
struct i2c_master_s *lpc17_40_i2cbus_initialize(int port)
{
struct lpc17_40_i2cdev_s *priv;
if (port > 1)
{
i2cerr("ERROR: LPC I2C Only supports ports 0 and 1\n");
return NULL;
}
irqstate_t flags;
uint32_t regval;
flags = enter_critical_section();
#ifdef CONFIG_LPC17_40_I2C0
if (port == 0)
{
priv = &g_i2c0dev;
priv->base = LPC17_40_I2C0_BASE;
priv->irqid = LPC17_40_IRQ_I2C0;
/* Enable clocking */
regval = getreg32(LPC17_40_SYSCON_PCONP);
regval |= SYSCON_PCONP_PCI2C0;
putreg32(regval, LPC17_40_SYSCON_PCONP);
regval = getreg32(LPC17_40_SYSCON_PCLKSEL0);
regval &= ~SYSCON_PCLKSEL0_I2C0_MASK;
regval |= (SYSCON_PCLKSEL_CCLK << SYSCON_PCLKSEL0_I2C0_SHIFT);
putreg32(regval, LPC17_40_SYSCON_PCLKSEL0);
/* Pin configuration */
lpc17_40_configgpio(GPIO_I2C0_SCL);
lpc17_40_configgpio(GPIO_I2C0_SDA);
/* Set default frequency */
lpc17_40_i2c_setfrequency(priv, CONFIG_LPC17_40_I2C0_FREQUENCY);
}
else
#endif
#ifdef CONFIG_LPC17_40_I2C1
if (port == 1)
{
priv = &g_i2c1dev;
priv->base = LPC17_40_I2C1_BASE;
priv->irqid = LPC17_40_IRQ_I2C1;
/* Enable clocking */
regval = getreg32(LPC17_40_SYSCON_PCONP);
regval |= SYSCON_PCONP_PCI2C1;
putreg32(regval, LPC17_40_SYSCON_PCONP);
regval = getreg32(LPC17_40_SYSCON_PCLKSEL1);
regval &= ~SYSCON_PCLKSEL1_I2C1_MASK;
regval |= (SYSCON_PCLKSEL_CCLK << SYSCON_PCLKSEL1_I2C1_SHIFT);
putreg32(regval, LPC17_40_SYSCON_PCLKSEL1);
/* Pin configuration */
lpc17_40_configgpio(GPIO_I2C1_SCL);
lpc17_40_configgpio(GPIO_I2C1_SDA);
/* Set default frequency */
lpc17_40_i2c_setfrequency(priv, CONFIG_LPC17_40_I2C1_FREQUENCY);
}
else
#endif
#ifdef CONFIG_LPC17_40_I2C2
if (port == 2)
{
priv = &g_i2c2dev;
priv->base = LPC17_40_I2C2_BASE;
priv->irqid = LPC17_40_IRQ_I2C2;
/* Enable clocking */
regval = getreg32(LPC17_40_SYSCON_PCONP);
regval |= SYSCON_PCONP_PCI2C2;
putreg32(regval, LPC17_40_SYSCON_PCONP);
regval = getreg32(LPC17_40_SYSCON_PCLKSEL1);
regval &= ~SYSCON_PCLKSEL1_I2C2_MASK;
regval |= (SYSCON_PCLKSEL_CCLK << SYSCON_PCLKSEL1_I2C2_SHIFT);
putreg32(regval, LPC17_40_SYSCON_PCLKSEL1);
/* Pin configuration */
lpc17_40_configgpio(GPIO_I2C2_SCL);
lpc17_40_configgpio(GPIO_I2C2_SDA);
/* Set default frequency */
lpc17_40_i2c_setfrequency(priv, CONFIG_LPC17_40_I2C2_FREQUENCY);
}
else
#endif
{
return NULL;
}
leave_critical_section(flags);
putreg32(I2C_CONSET_I2EN, priv->base + LPC17_40_I2C_CONSET_OFFSET);
/* Initialize semaphores */
nxsem_init(&priv->mutex, 0, 1);
nxsem_init(&priv->wait, 0, 0);
/* The wait semaphore is used for signaling and, hence, should not have
* priority inheritance enabled.
*/
nxsem_setprotocol(&priv->wait, SEM_PRIO_NONE);
/* Allocate a watchdog timer */
priv->timeout = wd_create();
DEBUGASSERT(priv->timeout != 0);
/* Attach Interrupt Handler */
irq_attach(priv->irqid, lpc17_40_i2c_interrupt, priv);
/* Enable Interrupt Handler */
up_enable_irq(priv->irqid);
/* Install our operations */
priv->dev.ops = &lpc17_40_i2c_ops;
return &priv->dev;
}
/****************************************************************************
* Name: lpc17_40_i2cbus_uninitialize
*
* Description:
* Uninitialise an I2C device
*
****************************************************************************/
int lpc17_40_i2cbus_uninitialize(FAR struct i2c_master_s * dev)
{
struct lpc17_40_i2cdev_s *priv = (struct lpc17_40_i2cdev_s *) dev;
/* Disable I2C */
putreg32(I2C_CONCLRT_I2ENC, priv->base + LPC17_40_I2C_CONCLR_OFFSET);
/* Reset data structures */
nxsem_destroy(&priv->mutex);
nxsem_destroy(&priv->wait);
/* Free the watchdog timer */
wd_delete(priv->timeout);
priv->timeout = NULL;
/* Disable interrupts */
up_disable_irq(priv->irqid);
/* Detach Interrupt Handler */
irq_detach(priv->irqid);
return OK;
}
#endif /* CONFIG_LPC17_40_I2C0 || CONFIG_LPC17_40_I2C1 || CONFIG_LPC17_40_I2C2 */
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