SAMA5 TWI: Some restructured needed by up_i2creset. Also timeout needs to vary with the size of the transfer and if debug is on or not
This commit is contained in:
Gregory Nutt
parent
ac5c4a6507
commit
c2ca4be4f5
@ -56,6 +56,7 @@
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#include <debug.h>
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#include <nuttx/arch.h>
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#include <nuttx/clock.h>
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#include <nuttx/i2c.h>
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#include <arch/irq.h>
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@ -96,8 +97,18 @@
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#endif
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/* Driver internal definitions *************************************************/
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/* If verbose I2C debug output is enable, then allow more time before we declare
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* a timeout. The debug output from twi_interrupt will really slow things down!
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*
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* With a very slow clock (say 100,000 Hz), less than 100 usec would be required
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* to transfer on byte. So these define a "long" timeout.
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*/
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#define TWI_TIMEOUT ((20 * CLK_TCK) / 1000) /* 20 mS */
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#if defined(CONFIG_DEBUG_I2C) && defined(CONFIG_DEBUG_VERBOSE)
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# define TWI_TIMEOUT_MSPB (50) /* 50 msec/byte */
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#else
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# define TWI_TIMEOUT_MSPB (5) /* 5 msec/byte */
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#endif
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/* Clocking to the TWO module(s) is provided by the main clocked, divided down
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* as necessary.
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@ -200,7 +211,7 @@ static inline void twi_putrel(struct twi_dev_s *priv, unsigned int offset,
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/* I2C transfer helper functions */
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static int twi_wait(struct twi_dev_s *priv);
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static int twi_wait(struct twi_dev_s *priv, unsigned int size);
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static void twi_wakeup(struct twi_dev_s *priv, int result);
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static int twi_interrupt(struct twi_dev_s *priv);
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#ifdef CONFIG_SAMA5_TWI0
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@ -248,7 +259,7 @@ static int twi_registercallback(FAR struct i2c_dev_s *dev,
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static uint32_t twi_hw_setfrequency(struct twi_dev_s *priv,
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uint32_t frequency);
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static void twi_hw_initialize(struct twi_dev_s *priv, uint32_t frequency);
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static void twi_initialize(struct twi_dev_s *priv, uint32_t frequency);
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static int twi_initialize(struct twi_dev_s *priv, uint32_t frequency);
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/*******************************************************************************
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* Private Data
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@ -504,11 +515,28 @@ static inline void twi_putrel(struct twi_dev_s *priv, unsigned int offset,
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*
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*******************************************************************************/
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static int twi_wait(struct twi_dev_s *priv)
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static int twi_wait(struct twi_dev_s *priv, unsigned int size)
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{
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/* Start a timeout to avoid hangs */
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uint32_t timeout;
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wd_start(priv->timeout, TWI_TIMEOUT, twi_timeout, 1, (uint32_t)priv);
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/* Calculate a timeout value based on the size of the transfer
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*
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* ticks = msec-per-byte * bytes / msec-per-tick
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*
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* There is no concern about arithmetic overflow for reasonable transfer sizes.
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*/
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timeout = (TWI_TIMEOUT_MSPB * size) / MSEC_PER_TICK;
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if (timeout < 1)
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{
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timeout = 1;
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}
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/* Then start the timeout. This timeout is needed to avoid hangs if/when an
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* TWI transfer stalls.
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*/
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wd_start(priv->timeout, timeout, twi_timeout, 1, (uint32_t)priv);
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/* Wait for either the TWI transfer or the timeout to complete */
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@ -720,7 +748,7 @@ static void twi_timeout(int argc, uint32_t arg, ...)
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{
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struct twi_dev_s *priv = (struct twi_dev_s *)arg;
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i2clldbg("TWI%d Timeout!\n", priv->attr->twi);
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i2clldbg("ERROR: TWI%d Timeout!\n", priv->attr->twi);
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twi_wakeup(priv, -ETIMEDOUT);
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}
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@ -903,7 +931,7 @@ static int twi_write(FAR struct i2c_dev_s *dev, const uint8_t *wbuffer, int wbuf
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twi_takesem(&priv->exclsem);
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/* Initiate the wrte */
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/* Initiate the write */
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priv->msg = &msg;
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priv->msgc = 1;
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@ -920,7 +948,7 @@ static int twi_write(FAR struct i2c_dev_s *dev, const uint8_t *wbuffer, int wbuf
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* we are waiting.
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*/
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ret = twi_wait(priv);
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ret = twi_wait(priv, wbuflen);
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if (ret < 0)
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{
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i2cdbg("ERROR: Transfer failed: %d\n", ret);
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@ -978,7 +1006,7 @@ static int twi_read(FAR struct i2c_dev_s *dev, uint8_t *rbuffer, int rbuflen)
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* we are waiting.
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*/
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ret = twi_wait(priv);
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ret = twi_wait(priv, rbuflen);
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if (ret < 0)
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{
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i2cdbg("ERROR: Transfer failed: %d\n", ret);
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@ -1001,28 +1029,38 @@ static int twi_writeread(FAR struct i2c_dev_s *dev, const uint8_t *wbuffer,
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int wbuflen, uint8_t *rbuffer, int rbuflen)
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{
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struct twi_dev_s *priv = (struct twi_dev_s *)dev;
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struct i2c_msg_s msgv[2];
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irqstate_t flags;
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int ret;
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struct i2c_msg_s msgv[2] =
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{
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{
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.addr = priv->address,
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.flags = priv->flags,
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.buffer = (uint8_t *)wbuffer, /* Override const */
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.length = wbuflen
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},
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{
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.addr = priv->address,
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.flags = priv->flags | ((rbuflen > 0) ? I2C_M_READ : I2C_M_NORESTART),
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.buffer = rbuffer,
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.length = (rbuflen < 0) ? -rbuflen : rbuflen
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}
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};
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DEBUGASSERT(dev != NULL);
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i2cvdbg("TWI%d wbuflen: %d rbuflen: %d\n", priv->attr->twi, wbuflen, rbuflen);
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/* Format two messages: The first is a write */
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msgv[0].addr = priv->address;
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msgv[0].flags = priv->flags;
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msgv[0].buffer = (uint8_t *)wbuffer; /* Override const */
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msgv[0].length = wbuflen;
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/* The second is either a read (rbuflen > 0) or a write (rbuflen < 0) with
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* no restart.
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*/
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if (rbuflen > 0)
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{
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msgv[1].flags = (priv->flags | I2C_M_READ);
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}
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else
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{
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msgv[1].flags = (priv->flags | I2C_M_NORESTART),
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rbuflen = -rbuflen;
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}
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msgv[1].addr = priv->address;
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msgv[1].buffer = rbuffer;
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msgv[1].length = rbuflen;
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/* Get exclusive access to the device */
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twi_takesem(&priv->exclsem);
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@ -1044,7 +1082,7 @@ static int twi_writeread(FAR struct i2c_dev_s *dev, const uint8_t *wbuffer,
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* while we are waiting.
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*/
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ret = twi_wait(priv);
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ret = twi_wait(priv, wbuflen + rbuflen);
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if (ret < 0)
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{
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i2cdbg("ERROR: Transfer failed: %d\n", ret);
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@ -1105,11 +1143,25 @@ static int twi_transfer(FAR struct i2c_dev_s *dev,
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{
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struct twi_dev_s *priv = (struct twi_dev_s *)dev;
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irqstate_t flags;
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unsigned int size;
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int i;
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int ret;
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DEBUGASSERT(dev != NULL);
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DEBUGASSERT(dev != NULL && msgs != NULL && count > 0);
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i2cvdbg("TWI%d count: %d\n", priv->attr->twi, count);
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/* Calculate the total transfer size so that we can calculate a reasonable
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* timeout value.
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*/
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size = 0;
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for (i = 0; i < count; i++)
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{
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size += msgs[i].length;
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}
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DEBUGASSERT(size > 0);
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/* Get exclusive access to the device */
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twi_takesem(&priv->exclsem);
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@ -1131,7 +1183,7 @@ static int twi_transfer(FAR struct i2c_dev_s *dev,
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* while we are waiting.
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*/
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ret = twi_wait(priv);
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ret = twi_wait(priv, size);
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if (ret < 0)
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{
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i2cdbg("ERROR: Transfer failed: %d\n", ret);
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@ -1312,18 +1364,45 @@ static void twi_hw_initialize(struct twi_dev_s *priv, uint32_t frequency)
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}
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/*******************************************************************************
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* Name: twi_sw_initialize
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* Name: twi_initialize
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*
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* Description:
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* Initialize/Re-initialize one TWI state structure. This logic performs
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* only repeatable initialization afte (1) the one-time initialization, and
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* (2) after each bus reset.
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* (2) after each bus reset (after up_i2cunintialize() has been called).
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*
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*******************************************************************************/
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static void twi_initialize(struct twi_dev_s *priv, uint32_t frequency)
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static int twi_initialize(struct twi_dev_s *priv, uint32_t frequency)
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{
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irqstate_t flags = irqsave();
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int ret;
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/* Allocate a watchdog timer */
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priv->timeout = wd_create();
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if (priv->timeout == NULL)
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{
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idbg("ERROR: Failed to allocate a timer\n");
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ret = -EAGAIN;
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goto errout_with_irq;
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}
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/* Attach Interrupt Handler */
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ret = irq_attach(priv->attr->irq, priv->attr->handler);
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if (ret < 0)
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{
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idbg("ERROR: Failed to attach irq %d\n", priv->attr->irq);
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goto errout_with_wdog;
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}
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/* Initialize the TWI driver structure (retaining address and flags) */
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priv->dev.ops = &g_twiops;
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sem_init(&priv->exclsem, 0, 1);
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sem_init(&priv->waitsem, 0, 0);
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/* Configure PIO pins */
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@ -1338,6 +1417,15 @@ static void twi_initialize(struct twi_dev_s *priv, uint32_t frequency)
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up_enable_irq(priv->attr->irq);
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irqrestore(flags);
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return OK;
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errout_with_wdog:
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wd_delete(priv->timeout);
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priv->timeout = NULL;
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errout_with_irq:
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irqrestore(flags);
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return ret;
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}
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/*******************************************************************************
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@ -1356,6 +1444,7 @@ struct i2c_dev_s *up_i2cinitialize(int bus)
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{
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struct twi_dev_s *priv;
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uint32_t frequency;
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int ret;
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i2cvdbg("Initializing TWI%d\n", bus);
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@ -1420,30 +1509,22 @@ struct i2c_dev_s *up_i2cinitialize(int bus)
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return NULL;
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}
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/* Perform all one time TWI initialization */
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/* Perform one-time TWI initialization. These may be set by driver logic
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* and the settings need to persist through up_i2creset.
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*/
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irqstate_t flags = irqsave();
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priv->dev.ops = &g_twiops;
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priv->address = 0;
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priv->flags = 0;
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sem_init(&priv->exclsem, 0, 1);
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sem_init(&priv->waitsem, 0, 0);
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/* Perform repeatable TWI initialization */
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/* Allocate a watchdog timer */
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ret = twi_initialize(priv, frequency);
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if (ret < 0)
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{
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idbg("ERROR: TWI Initialization failed: %d\n", ret);
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return NULL;
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}
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priv->timeout = wd_create();
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DEBUGASSERT(priv->timeout != 0);
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/* Attach Interrupt Handler */
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irq_attach(priv->attr->irq, priv->attr->handler);
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/* Now perform repeatable initialization */
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twi_initialize(priv, frequency);
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irqrestore(flags);
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return &priv->dev;
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}
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@ -1602,8 +1683,11 @@ int up_i2creset(FAR struct i2c_dev_s *dev)
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/* Re-initialize the port (using the saved frequency) */
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twi_initialize(priv, frequency);
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ret = OK;
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ret = twi_initialize(priv, frequency);
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if (ret < 0)
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{
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idbg("ERROR: TWI Initialization failed: %d\n", ret);
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}
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out:
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