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Commit 27be48a1 authored by Gregory Nutt's avatar Gregory Nutt
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SAMA5 I2C Reset: More changes... still does not work right

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arch/arm/src/sama5/sam_twi.c
+ 85
− 109
View file @ 27be48a1
......@@ -70,7 +70,6 @@
#include "sam_periphclks.h"
#include "sam_pio.h"
#include "sam_twi.h"
#include "sam_pmc.h" // REMOVE ME
#if defined(CONFIG_SAMA5_TWI0) || defined(CONFIG_SAMA5_TWI1) || \
defined(CONFIG_SAMA5_TWI2) || defined(CONFIG_SAMA5_TWI3)
......@@ -110,7 +109,7 @@
# define TWI_TIMEOUT_MSPB (5) /* 5 msec/byte */
#endif
/* Clocking to the TWO module(s) is provided by the main clocked, divided down
/* Clocking to the TWI module(s) is provided by the main clock, divided down
* as necessary.
*/
......@@ -162,7 +161,10 @@ struct twi_dev_s
struct i2c_dev_s dev; /* Generic I2C device */
const struct twi_attr_s *attr; /* Invariant attributes of TWI device */
struct i2c_msg_s *msg; /* Message list */
uint32_t frequency; /* TWI clock frequency */
uint32_t twiclk; /* TWI input clock frequency */
#ifdef CONFIG_I2C_RESET
uint32_t frequency; /* TWI transfer clock frequency */
#endif
uint16_t address; /* Slave address */
uint16_t flags; /* Transfer flags */
uint8_t msgc; /* Number of message in the message list */
......@@ -259,7 +261,6 @@ static int twi_registercallback(FAR struct i2c_dev_s *dev,
static uint32_t twi_hw_setfrequency(struct twi_dev_s *priv,
uint32_t frequency);
static void twi_hw_initialize(struct twi_dev_s *priv, uint32_t frequency);
static int twi_initialize(struct twi_dev_s *priv, uint32_t frequency);
/*******************************************************************************
* Private Data
......@@ -1245,9 +1246,9 @@ static uint32_t twi_hw_setfrequency(struct twi_dev_s *priv, uint32_t frequency)
for (ckdiv = 0; ckdiv < 8; ckdiv++)
{
/* Calulate the CLDIV value using the current CKDIV guess */
/* Calculate the CLDIV value using the current CKDIV guess */
cldiv = ((priv->frequency / (frequency << 1)) - 4) / (1 << ckdiv);
cldiv = ((priv->twiclk / (frequency << 1)) - 4) / (1 << ckdiv);
/* Is CLDIV in range? */
......@@ -1270,12 +1271,19 @@ static uint32_t twi_hw_setfrequency(struct twi_dev_s *priv, uint32_t frequency)
((uint32_t)cldiv << TWI_CWGR_CLDIV_SHIFT);
twi_putrel(priv, SAM_TWI_CWGR_OFFSET, regval);
/* Return the actual frequency */
/* Calculate the actual I2C frequency */
actual = (priv->frequency / 2) / (((1 << ckdiv) * cldiv) + 2);
actual = (priv->twiclk / 2) / (((1 << ckdiv) * cldiv) + 2);
i2cvdbg("TWI%d frequency: %d ckdiv: %d cldiv: %d actual: %d\n",
priv->attr->twi, frequency, ckdiv, cldiv, actual);
/* Save the requested frequency (for I2C reset) and return the
* actual frequency.
*/
#ifdef CONFIG_I2C_RESET
priv->frequency = frequency;
#endif
return actual;
}
......@@ -1283,17 +1291,25 @@ static uint32_t twi_hw_setfrequency(struct twi_dev_s *priv, uint32_t frequency)
* Name: twi_hw_initialize
*
* Description:
* Initialize one TWI peripheral for I2C operation
* Initialize/Re-initialize the TWI peripheral. This logic performs only
* repeatable initialization after either (1) the one-time initialization, or
* (2) after each bus reset.
*
*******************************************************************************/
static void twi_hw_initialize(struct twi_dev_s *priv, uint32_t frequency)
{
irqstate_t flags = irqsave();
uint32_t regval;
uint32_t mck;
i2cvdbg("TWI%d Initializing\n", priv->attr->twi);
/* Configure PIO pins */
sam_configpio(priv->attr->sclcfg);
sam_configpio(priv->attr->sdacfg);
/* Enable peripheral clocking */
twi_enableclk(priv);
......@@ -1326,30 +1342,30 @@ static void twi_hw_initialize(struct twi_dev_s *priv, uint32_t frequency)
DEBUGASSERT((mck >> 3) <= TWI_MAX_FREQUENCY);
if (mck <= TWI_MAX_FREQUENCY)
{
priv->frequency = mck;
regval = PMC_PCR_DIV1;
priv->twiclk = mck;
regval = PMC_PCR_DIV1;
}
else if ((mck >> 1) <= TWI_MAX_FREQUENCY)
{
priv->frequency = (mck >> 1);
regval = PMC_PCR_DIV2;
priv->twiclk = (mck >> 1);
regval = PMC_PCR_DIV2;
}
else if ((mck >> 2) <= TWI_MAX_FREQUENCY)
{
priv->frequency = (mck >> 2);
regval = PMC_PCR_DIV4;
priv->twiclk = (mck >> 2);
regval = PMC_PCR_DIV4;
}
else /* if ((mck >> 3) <= TWI_MAX_FREQUENCY) */
{
priv->frequency = (mck >> 3);
regval = PMC_PCR_DIV8;
priv->twiclk = (mck >> 3);
regval = PMC_PCR_DIV8;
}
#else
/* No DIV field in the PCR register */
priv->frequency = mck;
regval = 0;
priv->twiclk = mck;
regval = 0;
#endif /* SAMA5_HAVE_PMC_PCR_DIV */
......@@ -1360,72 +1376,12 @@ static void twi_hw_initialize(struct twi_dev_s *priv, uint32_t frequency)
/* Set the initial TWI data transfer frequency */
(void)twi_hw_setfrequency(priv, frequency);
}
/*******************************************************************************
* Name: twi_initialize
*
* Description:
* Initialize/Re-initialize one TWI state structure. This logic performs
* only repeatable initialization afte (1) the one-time initialization, and
* (2) after each bus reset (after up_i2cunintialize() has been called).
*
*******************************************************************************/
static int twi_initialize(struct twi_dev_s *priv, uint32_t frequency)
{
irqstate_t flags = irqsave();
int ret;
/* Allocate a watchdog timer */
priv->timeout = wd_create();
if (priv->timeout == NULL)
{
idbg("ERROR: Failed to allocate a timer\n");
ret = -EAGAIN;
goto errout_with_irq;
}
/* Attach Interrupt Handler */
ret = irq_attach(priv->attr->irq, priv->attr->handler);
if (ret < 0)
{
idbg("ERROR: Failed to attach irq %d\n", priv->attr->irq);
goto errout_with_wdog;
}
/* Initialize the TWI driver structure (retaining address and flags) */
priv->dev.ops = &g_twiops;
sem_init(&priv->exclsem, 0, 1);
sem_init(&priv->waitsem, 0, 0);
/* Configure PIO pins */
sam_configpio(priv->attr->sclcfg);
sam_configpio(priv->attr->sdacfg);
/* Configure and enable the TWI hardware */
twi_hw_initialize(priv, frequency);
twi_hw_setfrequency(priv, frequency);
/* Enable Interrupts */
up_enable_irq(priv->attr->irq);
irqrestore(flags);
return OK;
errout_with_wdog:
wd_delete(priv->timeout);
priv->timeout = NULL;
errout_with_irq:
irqrestore(flags);
return ret;
}
/*******************************************************************************
......@@ -1444,6 +1400,7 @@ struct i2c_dev_s *up_i2cinitialize(int bus)
{
struct twi_dev_s *priv;
uint32_t frequency;
irqstate_t flags;
int ret;
i2cvdbg("Initializing TWI%d\n", bus);
......@@ -1509,30 +1466,57 @@ struct i2c_dev_s *up_i2cinitialize(int bus)
return NULL;
}
/* Perform one-time TWI initialization. These may be set by driver logic
* and the settings need to persist through up_i2creset.
*/
/* Perform one-time TWI initialization */
priv->address = 0;
priv->flags = 0;
flags = irqsave();
/* Perform repeatable TWI initialization */
/* Allocate a watchdog timer */
ret = twi_initialize(priv, frequency);
priv->timeout = wd_create();
if (priv->timeout == NULL)
{
idbg("ERROR: Failed to allocate a timer\n");
goto errout_with_irq;
}
/* Attach Interrupt Handler */
ret = irq_attach(priv->attr->irq, priv->attr->handler);
if (ret < 0)
{
idbg("ERROR: TWI Initialization failed: %d\n", ret);
return NULL;
idbg("ERROR: Failed to attach irq %d\n", priv->attr->irq);
goto errout_with_wdog;
}
/* Initialize the TWI driver structure */
priv->dev.ops = &g_twiops;
priv->address = 0;
priv->flags = 0;
(void)sem_init(&priv->exclsem, 0, 1);
(void)sem_init(&priv->waitsem, 0, 0);
/* Perform repeatable TWI hardware initialization */
twi_hw_initialize(priv, frequency);
irqrestore(flags);
return &priv->dev;
errout_with_wdog:
wd_delete(priv->timeout);
priv->timeout = NULL;
errout_with_irq:
irqrestore(flags);
return NULL;
}
/*******************************************************************************
* Name: up_i2cuninitalize
*
* Description:
* Uninitialise an I2C device
* Uninitialize an I2C device
*
*******************************************************************************/
......@@ -1542,7 +1526,7 @@ int up_i2cuninitialize(FAR struct i2c_dev_s *dev)
i2cvdbg("TWI%d Un-initializing\n", priv->attr->twi);
/* Disable interrupts */
/* Disable TWI interrupts */
up_disable_irq(priv->attr->irq);
......@@ -1558,7 +1542,7 @@ int up_i2cuninitialize(FAR struct i2c_dev_s *dev)
/* Detach Interrupt Handler */
irq_detach(priv->attr->irq);
(void)irq_detach(priv->attr->irq);
return OK;
}
......@@ -1576,7 +1560,6 @@ int up_i2creset(FAR struct i2c_dev_s *dev)
struct twi_dev_s *priv = (struct twi_dev_s *)dev;
unsigned int clockcnt;
unsigned int stretchcnt;
uint32_t frequency;
uint32_t sclpin;
uint32_t sdapin;
int ret;
......@@ -1587,15 +1570,11 @@ int up_i2creset(FAR struct i2c_dev_s *dev)
twi_takesem(&priv->exclsem);
/* Uninitialize the port, saving the currently selected frequency. Other
* dynamically configured data (address and transfer flags) will be
* preserved.
*/
/* Disable TWI interrupts */
frequency = priv->frequency;
up_i2cuninitialize(&priv->dev);
up_disable_irq(priv->attr->irq);
/* Use GPIO configuration to un-wedge the bus */
/* Use PIO configuration to un-wedge the bus */
sclpin = MKI2C_OUTPUT(priv->attr->sclcfg);
sdapin = MKI2C_OUTPUT(priv->attr->sdacfg);
......@@ -1628,7 +1607,7 @@ int up_i2creset(FAR struct i2c_dev_s *dev)
if (clockcnt++ > 10)
{
ret = -ETIMEDOUT;
goto out;
goto errout_with_lock;
}
/* Sniff to make sure that clock stretching has finished. SCL should
......@@ -1645,7 +1624,7 @@ int up_i2creset(FAR struct i2c_dev_s *dev)
if (stretchcnt++ > 10)
{
ret = -EAGAIN;
goto out;
goto errout_with_lock;
}
up_udelay(10);
......@@ -1681,15 +1660,12 @@ int up_i2creset(FAR struct i2c_dev_s *dev)
sam_pio_forceclk(sclpin, false);
sam_pio_forceclk(sdapin, false);
/* Re-initialize the port (using the saved frequency) */
/* Re-initialize the port hardware */
ret = twi_initialize(priv, frequency);
if (ret < 0)
{
idbg("ERROR: TWI Initialization failed: %d\n", ret);
}
twi_hw_initialize(priv, priv->frequency);
ret = OK;
out:
errout_with_lock:
/* Release our lock on the bus */
......
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