/**************************************************************************** * arch/arm/src/lpc17xx/lpc17_i2c.c * * Copyright (C) 2012, 2014-2016 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * Copyright (C) 2011 Li Zhuoyi. All rights reserved. * Author: Li Zhuoyi (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 * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include "chip.h" #include "up_arch.h" #include "up_internal.h" #include "chip.h" #include "chip/lpc17_syscon.h" #include "lpc17_gpio.h" #include "lpc17_i2c.h" #if defined(CONFIG_LPC17_I2C0) || defined(CONFIG_LPC17_I2C1) || defined(CONFIG_LPC17_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_I2C0_FREQUENCY # define CONFIG_LPC17_I2C0_FREQUENCY 100000 #endif #ifndef CONFIG_LPC17_I2C1_FREQUENCY # define CONFIG_LPC17_I2C1_FREQUENCY 100000 #endif #ifndef CONFIG_LPC17_I2C2_FREQUENCY # define CONFIG_LPC17_I2C2_FREQUENCY 100000 #endif #define I2C_TIMEOUT (20 * 1000/CONFIG_USEC_PER_TICK) /* 20 mS */ #define LPC17_I2C1_FREQUENCY 400000 /**************************************************************************** * Private Types ****************************************************************************/ struct lpc17_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_i2c_start(struct lpc17_i2cdev_s *priv); static void lpc17_i2c_stop(struct lpc17_i2cdev_s *priv); static int lpc17_i2c_interrupt(int irq, FAR void *context); static void lpc17_i2c_timeout(int argc, uint32_t arg, ...); static void lpc17_i2c_setfrequency(struct lpc17_i2cdev_s *priv, uint32_t frequency); /* I2C device operations */ static int lpc17_i2c_transfer(FAR struct i2c_master_s *dev, FAR struct i2c_msg_s *msgs, int count); static void lpc17_stopnext(struct lpc17_i2cdev_s *priv); /**************************************************************************** * Private Data ****************************************************************************/ #ifdef CONFIG_LPC17_I2C0 static struct lpc17_i2cdev_s g_i2c0dev; #endif #ifdef CONFIG_LPC17_I2C1 static struct lpc17_i2cdev_s g_i2c1dev; #endif #ifdef CONFIG_LPC17_I2C2 static struct lpc17_i2cdev_s g_i2c2dev; #endif struct i2c_ops_s lpc17_i2c_ops = { .transfer = lpc17_i2c_transfer }; /**************************************************************************** * Name: lpc17_i2c_setfrequency * * Description: * Set the frequency for the next transfer * ****************************************************************************/ static void lpc17_i2c_setfrequency(struct lpc17_i2cdev_s *priv, uint32_t frequency); { if (frequency != priv->frequency) { if (frequency > 100000) { /* Asymetric per 400Khz I2C spec */ putreg32(LPC17_CCLK / (83 + 47) * 47 / frequency, priv->base + LPC17_I2C_SCLH_OFFSET); putreg32(LPC17_CCLK / (83 + 47) * 83 / frequency, priv->base + LPC17_I2C_SCLL_OFFSET); } else { /* 50/50 mark space ratio */ putreg32(LPC17_CCLK / 100 * 50 / frequency, priv->base + LPC17_I2C_SCLH_OFFSET); putreg32(LPC17_CCLK / 100 * 50 / frequency, priv->base + LPC17_I2C_SCLL_OFFSET); } priv->frequency = frequency; } } /**************************************************************************** * Name: lpc17_i2c_start * * Description: * Perform a I2C transfer start * ****************************************************************************/ static int lpc17_i2c_start(struct lpc17_i2cdev_s *priv) { int ret = -1; putreg32(I2C_CONCLR_STAC | I2C_CONCLR_SIC, priv->base + LPC17_I2C_CONCLR_OFFSET); putreg32(I2C_CONSET_STA, priv->base + LPC17_I2C_CONSET_OFFSET); wd_start(priv->timeout, I2C_TIMEOUT, lpc17_i2c_timeout, 1, (uint32_t)priv); sem_wait(&priv->wait); wd_cancel(priv->timeout); return priv->nmsg; } /**************************************************************************** * Name: lpc17_i2c_stop * * Description: * Perform a I2C transfer stop * ****************************************************************************/ static void lpc17_i2c_stop(struct lpc17_i2cdev_s *priv) { if (priv->state != 0x38) { putreg32(I2C_CONSET_STO | I2C_CONSET_AA, priv->base + LPC17_I2C_CONSET_OFFSET); } sem_post(&priv->wait); } /**************************************************************************** * Name: lpc17_i2c_timeout * * Description: * Watchdog timer for timeout of I2C operation * ****************************************************************************/ static void lpc17_i2c_timeout(int argc, uint32_t arg, ...) { struct lpc17_i2cdev_s *priv = (struct lpc17_i2cdev_s *)arg; irqstate_t flags = irqsave(); priv->state = 0xff; sem_post(&priv->wait); irqrestore(flags); } /**************************************************************************** * Name: lpc17_i2c_transfer * * Description: * Perform a sequence of I2C transfers * ****************************************************************************/ static int lpc17_i2c_transfer(FAR struct i2c_master_s *dev, FAR struct i2c_msg_s *msgs, int count) { struct lpc17_i2cdev_s *priv = (struct lpc17_i2cdev_s *)dev; int ret; DEBUGASSERT(dev != NULL && msgs != NULL && count > 0); /* Get exclusive access to the I2C bus */ sem_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_i2c_setfrequency(priv, msgs->frequency); /* Perform the transfer */ ret = lpc17_i2c_start(priv); sem_post(&priv->mutex); return ret; } /**************************************************************************** * Name: lpc17_i2c_interrupt * * Description: * Check if we need to issue STOP at the next message * ****************************************************************************/ static void lpc17_stopnext(struct lpc17_i2cdev_s *priv) { priv->nmsg--; if (priv->nmsg > 0) { priv->msgs++; putreg32(I2C_CONSET_STA, priv->base + LPC17_I2C_CONSET_OFFSET); } else { lpc17_i2c_stop(priv); } } /**************************************************************************** * Name: lpc17_i2c_interrupt * * Description: * The I2C Interrupt Handler * ****************************************************************************/ static int lpc17_i2c_interrupt(int irq, FAR void *context) { struct lpc17_i2cdev_s *priv; struct i2c_msg_s *msg; uint32_t state; #ifdef CONFIG_LPC17_I2C0 if (irq == LPC17_IRQ_I2C0) { priv = &g_i2c0dev; } else #endif #ifdef CONFIG_LPC17_I2C1 if (irq == LPC17_IRQ_I2C1) { priv = &g_i2c1dev; } else #endif #ifdef CONFIG_LPC17_I2C2 if (irq == LPC17_IRQ_I2C2) { priv = &g_i2c2dev; } else #endif { PANIC(); } /* Reference UM10360 19.10.5 */ state = getreg32(priv->base + LPC17_I2C_STAT_OFFSET); msg = priv->msgs; 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_I2C_DAT_OFFSET); /* Clear start bit */ putreg32(I2C_CONCLR_STAC, priv->base + LPC17_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_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_I2C_DAT_OFFSET); /* Put next byte */ } else { lpc17_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_I2C_CONSET_OFFSET); /* Set ACK next read */ } else { putreg32(I2C_CONCLR_AAC, priv->base + LPC17_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_I2C_BUFR_OFFSET); if (priv->rdcnt >= (msg->length - 1)) { putreg32(I2C_CONCLR_AAC, priv->base + LPC17_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_I2C_BUFR_OFFSET); lpc17_stopnext(priv); break; default: lpc17_i2c_stop(priv); break; } putreg32(I2C_CONCLR_SIC, priv->base + LPC17_I2C_CONCLR_OFFSET); /* clear interrupt */ return OK; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: up_i2cinitialize * * Description: * Initialise an I2C device * ****************************************************************************/ struct i2c_master_s *up_i2cinitialize(int port) { struct lpc17_i2cdev_s *priv; if (port > 1) { dbg("lpc I2C Only support 0,1\n"); return NULL; } irqstate_t flags; uint32_t regval; flags = irqsave(); #ifdef CONFIG_LPC17_I2C0 if (port == 0) { priv = &g_i2c0dev; priv->base = LPC17_I2C0_BASE; priv->irqid = LPC17_IRQ_I2C0; /* Enable clocking */ regval = getreg32(LPC17_SYSCON_PCONP); regval |= SYSCON_PCONP_PCI2C0; putreg32(regval, LPC17_SYSCON_PCONP); regval = getreg32(LPC17_SYSCON_PCLKSEL0); regval &= ~SYSCON_PCLKSEL0_I2C0_MASK; regval |= (SYSCON_PCLKSEL_CCLK << SYSCON_PCLKSEL0_I2C0_SHIFT); putreg32(regval, LPC17_SYSCON_PCLKSEL0); /* Pin configuration */ lpc17_configgpio(GPIO_I2C0_SCL); lpc17_configgpio(GPIO_I2C0_SDA); /* Set default frequency */ lpc17_i2c_setfrequency(priv, CONFIG_LPC17_I2C0_FREQUENCY); } else #endif #ifdef CONFIG_LPC17_I2C1 if (port == 1) { priv = &g_i2c1dev; priv->base = LPC17_I2C1_BASE; priv->irqid = LPC17_IRQ_I2C1; /* Enable clocking */ regval = getreg32(LPC17_SYSCON_PCONP); regval |= SYSCON_PCONP_PCI2C1; putreg32(regval, LPC17_SYSCON_PCONP); regval = getreg32(LPC17_SYSCON_PCLKSEL1); regval &= ~SYSCON_PCLKSEL1_I2C1_MASK; regval |= (SYSCON_PCLKSEL_CCLK << SYSCON_PCLKSEL1_I2C1_SHIFT); putreg32(regval, LPC17_SYSCON_PCLKSEL1); /* Pin configuration */ lpc17_configgpio(GPIO_I2C1_SCL); lpc17_configgpio(GPIO_I2C1_SDA); /* Set default frequency */ lpc17_i2c_setfrequency(priv, CONFIG_LPC17_I2C1_FREQUENCY); } else #endif #ifdef CONFIG_LPC17_I2C2 if (port == 2) { priv = &g_i2c2dev; priv->base = LPC17_I2C2_BASE; priv->irqid = LPC17_IRQ_I2C2; /* Enable clocking */ regval = getreg32(LPC17_SYSCON_PCONP); regval |= SYSCON_PCONP_PCI2C2; putreg32(regval, LPC17_SYSCON_PCONP); regval = getreg32(LPC17_SYSCON_PCLKSEL1); regval &= ~SYSCON_PCLKSEL1_I2C2_MASK; regval |= (SYSCON_PCLKSEL_CCLK << SYSCON_PCLKSEL1_I2C2_SHIFT); putreg32(regval, LPC17_SYSCON_PCLKSEL1); /* Pin configuration */ lpc17_configgpio(GPIO_I2C2_SCL); lpc17_configgpio(GPIO_I2C2_SDA); /* Set default frequency */ lpc17_i2c_setfrequency(priv, CONFIG_LPC17_I2C2_FREQUENCY); } else #endif { return NULL; } irqrestore(flags); putreg32(I2C_CONSET_I2EN, priv->base + LPC17_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, lpc17_i2c_interrupt); /* Enable Interrupt Handler */ up_enable_irq(priv->irqid); /* Install our operations */ priv->dev.ops = &lpc17_i2c_ops; return &priv->dev; } /**************************************************************************** * Name: up_i2cuninitalize * * Description: * Uninitialise an I2C device * ****************************************************************************/ int up_i2cuninitialize(FAR struct i2c_master_s * dev) { struct lpc17_i2cdev_s *priv = (struct lpc17_i2cdev_s *) dev; /* Disable I2C */ putreg32(I2C_CONCLRT_I2ENC, priv->base + LPC17_I2C_CONCLR_OFFSET); /* Reset data structures */ sem_destroy(&priv->mutex); sem_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; } /**************************************************************************** * Name: up_i2creset * * Description: * Reset an I2C bus * ****************************************************************************/ #ifdef CONFIG_I2C_RESET int up_i2creset(FAR struct i2c_master_s * dev) { return OK; } #endif /* CONFIG_I2C_RESET */ #endif /* CONFIG_LPC17_I2C0 || CONFIG_LPC17_I2C1 || CONFIG_LPC17_I2C2 */