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MAX_CARLINK_A270S/MXC_A27-PCB4.5-270S/ArkmicroFiles/libcpu-amt630hv100/source/i2c-dw.c

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#include <string.h>
#include <stdio.h>
#include "FreeRTOS.h"
#include "chip.h"
#include "board.h"
#include "errno.h"
#if defined(HW_I2C0_SUPPORT) || defined(HW_I2C1_SUPPORT)
static char *abort_sources[] = {
[ABRT_7B_ADDR_NOACK] =
"slave address not acknowledged (7bit mode)",
[ABRT_10ADDR1_NOACK] =
"first address byte not acknowledged (10bit mode)",
[ABRT_10ADDR2_NOACK] =
"second address byte not acknowledged (10bit mode)",
[ABRT_TXDATA_NOACK] =
"data not acknowledged",
[ABRT_GCALL_NOACK] =
"no acknowledgement for a general call",
[ABRT_GCALL_READ] =
"read after general call",
[ABRT_SBYTE_ACKDET] =
"start byte acknowledged",
[ABRT_SBYTE_NORSTRT] =
"trying to send start byte when restart is disabled",
[ABRT_10B_RD_NORSTRT] =
"trying to read when restart is disabled (10bit mode)",
[ABRT_MASTER_DIS] =
"trying to use disabled adapter",
[ARB_LOST] =
"lost arbitration",
[ABRT_SLAVE_FLUSH_TXFIFO] =
"read command so flush old data in the TX FIFO",
[ABRT_SLAVE_ARBLOST] =
"slave lost the bus while transmitting data to a remote master",
[ABRT_SLAVE_RD_INTX] =
"incorrect slave-transmitter mode configuration",
};
u32 dw_readl(struct dw_i2c_dev *dev, int offset)
{
return readl(dev->base + offset);
}
void dw_writel(struct dw_i2c_dev *dev, u32 b, int offset)
{
writel(b, dev->base + offset);
}
int i2c_dw_acquire_lock(struct dw_i2c_dev *dev)
{
int ret;
if (!dev->acquire_lock)
return 0;
ret = dev->acquire_lock(dev);
if (!ret)
return 0;
TRACE_ERROR("couldn't acquire bus ownership\n");
return ret;
}
void i2c_dw_release_lock(struct dw_i2c_dev *dev)
{
if (dev->release_lock)
dev->release_lock(dev);
}
/**
* i2c_dw_set_reg_access() - Set register access flags
* @dev: device private data
*
* Autodetects needed register access mode and sets access flags accordingly.
* This must be called before doing any other register access.
*/
int i2c_dw_set_reg_access(struct dw_i2c_dev *dev)
{
u32 reg;
int ret;
ret = i2c_dw_acquire_lock(dev);
if (ret)
return ret;
reg = dw_readl(dev, DW_IC_COMP_TYPE);
i2c_dw_release_lock(dev);
if (reg == ___constant_swab32(DW_IC_COMP_TYPE_VALUE)) {
/* Configure register endianess access */
dev->flags |= ACCESS_SWAP;
} else if (reg == (DW_IC_COMP_TYPE_VALUE & 0x0000ffff)) {
/* Configure register access mode 16bit */
dev->flags |= ACCESS_16BIT;
} else if (reg != DW_IC_COMP_TYPE_VALUE) {
TRACE_ERROR("Unknown Synopsys component type: 0x%08x\n", reg);
return -ENODEV;
}
return 0;
}
u32 i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset)
{
/*
* DesignWare I2C core doesn't seem to have solid strategy to meet
* the tHD;STA timing spec. Configuring _HCNT based on tHIGH spec
* will result in violation of the tHD;STA spec.
*/
if (cond)
/*
* Conditional expression:
*
* IC_[FS]S_SCL_HCNT + (1+4+3) >= IC_CLK * tHIGH
*
* This is based on the DW manuals, and represents an ideal
* configuration. The resulting I2C bus speed will be
* faster than any of the others.
*
* If your hardware is free from tHD;STA issue, try this one.
*/
return (ic_clk * tSYMBOL + 500000) / 1000000 - 8 + offset;
else
/*
* Conditional expression:
*
* IC_[FS]S_SCL_HCNT + 3 >= IC_CLK * (tHD;STA + tf)
*
* This is just experimental rule; the tHD;STA period turned
* out to be proportinal to (_HCNT + 3). With this setting,
* we could meet both tHIGH and tHD;STA timing specs.
*
* If unsure, you'd better to take this alternative.
*
* The reason why we need to take into account "tf" here,
* is the same as described in i2c_dw_scl_lcnt().
*/
return (ic_clk * (tSYMBOL + tf) + 500000) / 1000000
- 3 + offset;
}
u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset)
{
/*
* Conditional expression:
*
* IC_[FS]S_SCL_LCNT + 1 >= IC_CLK * (tLOW + tf)
*
* DW I2C core starts counting the SCL CNTs for the LOW period
* of the SCL clock (tLOW) as soon as it pulls the SCL line.
* In order to meet the tLOW timing spec, we need to take into
* account the fall time of SCL signal (tf). Default tf value
* should be 0.3 us, for safety.
*/
return ((ic_clk * (tLOW + tf) + 500000) / 1000000) - 1 + offset;
}
int i2c_dw_set_sda_hold(struct dw_i2c_dev *dev)
{
u32 reg;
int ret;
ret = i2c_dw_acquire_lock(dev);
if (ret)
return ret;
/* Configure SDA Hold Time if required */
reg = dw_readl(dev, DW_IC_COMP_VERSION);
if (reg >= DW_IC_SDA_HOLD_MIN_VERS) {
if (!dev->sda_hold_time) {
/* Keep previous hold time setting if no one set it */
dev->sda_hold_time = dw_readl(dev, DW_IC_SDA_HOLD);
}
/*
* Workaround for avoiding TX arbitration lost in case I2C
* slave pulls SDA down "too quickly" after falling egde of
* SCL by enabling non-zero SDA RX hold. Specification says it
* extends incoming SDA low to high transition while SCL is
* high but it apprears to help also above issue.
*/
if (!(dev->sda_hold_time & DW_IC_SDA_HOLD_RX_MASK))
dev->sda_hold_time |= 1 << DW_IC_SDA_HOLD_RX_SHIFT;
TRACE_DEBUG("SDA Hold Time TX:RX = %d:%d\n",
dev->sda_hold_time & ~(u32)DW_IC_SDA_HOLD_RX_MASK,
dev->sda_hold_time >> DW_IC_SDA_HOLD_RX_SHIFT);
} else if (dev->sda_hold_time) {
TRACE_WARNING("Hardware too old to adjust SDA hold time.\n");
dev->sda_hold_time = 0;
}
i2c_dw_release_lock(dev);
return 0;
}
static inline void __i2c_dw_enable(struct dw_i2c_dev *dev)
{
dw_writel(dev, 1, DW_IC_ENABLE);
}
static inline void __i2c_dw_disable_nowait(struct dw_i2c_dev *dev)
{
dw_writel(dev, 0, DW_IC_ENABLE);
}
void __i2c_dw_disable(struct dw_i2c_dev *dev)
{
int timeout = 100;
do {
__i2c_dw_disable_nowait(dev);
/*
* The enable status register may be unimplemented, but
* in that case this test reads zero and exits the loop.
*/
if ((dw_readl(dev, DW_IC_ENABLE_STATUS) & 1) == 0)
return;
/*
* Wait 10 times the signaling period of the highest I2C
* transfer supported by the driver (for 400KHz this is
* 25us) as described in the DesignWare I2C databook.
*/
vTaskDelay(pdMS_TO_TICKS(1));
} while (timeout--);
TRACE_WARNING("timeout in disabling adapter\n");
}
unsigned long i2c_dw_clk_rate(struct dw_i2c_dev *dev)
{
/*
* Clock is not necessary if we got LCNT/HCNT values directly from
* the platform code.
*/
if (!dev->get_clk_rate_khz)
return 0;
return dev->get_clk_rate_khz(dev);
}
/*
* Waiting for bus not busy
*/
int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev)
{
int timeout = TIMEOUT;
while (dw_readl(dev, DW_IC_STATUS) & DW_IC_STATUS_ACTIVITY) {
if (timeout <= 0) {
TRACE_WARNING("timeout waiting for bus ready\n");
return -ETIMEDOUT;
}
timeout--;
vTaskDelay(pdMS_TO_TICKS(1));
}
return 0;
}
int i2c_dw_handle_tx_abort(struct dw_i2c_dev *dev)
{
unsigned long abort_source = dev->abort_source;
int i;
if (abort_source & DW_IC_TX_ABRT_NOACK) {
for (i = 0; i < ARRAY_SIZE(abort_sources); i++) {
if (abort_source & (1 << i))
TRACE_DEBUG("%s: %s\n", __func__, abort_sources[i]);
}
return -EREMOTEIO;
}
for (i = 0; i < ARRAY_SIZE(abort_sources); i++) {
if (abort_source & (1 << i))
TRACE_ERROR("%s: %s\n", __func__, abort_sources[i]);
}
if (abort_source & DW_IC_TX_ARB_LOST)
return -EAGAIN;
else if (abort_source & DW_IC_TX_ABRT_GCALL_READ)
return -EINVAL; /* wrong msgs[] data */
else
return -EIO;
}
void i2c_dw_disable(struct dw_i2c_dev *dev)
{
/* Disable controller */
__i2c_dw_disable(dev);
/* Disable all interupts */
dw_writel(dev, 0, DW_IC_INTR_MASK);
dw_readl(dev, DW_IC_CLR_INTR);
}
void i2c_dw_disable_int(struct dw_i2c_dev *dev)
{
dw_writel(dev, 0, DW_IC_INTR_MASK);
}
u32 i2c_dw_read_comp_param(struct dw_i2c_dev *dev)
{
return dw_readl(dev, DW_IC_COMP_PARAM_1);
}
static void i2c_dw_configure_fifo_master(struct dw_i2c_dev *dev)
{
/* Configure Tx/Rx FIFO threshold levels */
dw_writel(dev, dev->tx_fifo_depth / 2, DW_IC_TX_TL);
dw_writel(dev, 0, DW_IC_RX_TL);
/* Configure the I2C master */
dw_writel(dev, dev->master_cfg, DW_IC_CON);
}
static int i2c_dw_set_timings_master(struct dw_i2c_dev *dev)
{
#if (TRACE_LEVEL >= TRACE_LEVEL_DEBUG)
const char *mode_str, *fp_str = "";
#endif
u32 comp_param1;
u32 sda_falling_time, scl_falling_time;
u32 ic_clk;
int ret;
ret = i2c_dw_acquire_lock(dev);
if (ret)
return ret;
comp_param1 = dw_readl(dev, DW_IC_COMP_PARAM_1);
i2c_dw_release_lock(dev);
/* Set standard and fast speed dividers for high/low periods */
sda_falling_time = dev->sda_falling_time ? dev->sda_falling_time : 300; /* ns */
scl_falling_time = dev->scl_falling_time ? dev->scl_falling_time : 300; /* ns */
/* Calculate SCL timing parameters for standard mode if not set */
if (!dev->ss_hcnt || !dev->ss_lcnt) {
ic_clk = i2c_dw_clk_rate(dev);
dev->ss_hcnt =
i2c_dw_scl_hcnt(ic_clk,
4000, /* tHD;STA = tHIGH = 4.0 us */
sda_falling_time,
0, /* 0: DW default, 1: Ideal */
0); /* No offset */
dev->ss_lcnt =
i2c_dw_scl_lcnt(ic_clk,
4700, /* tLOW = 4.7 us */
scl_falling_time,
0); /* No offset */
}
TRACE_DEBUG("Standard Mode HCNT:LCNT = %d:%d\n", dev->ss_hcnt, dev->ss_lcnt);
/*
* Set SCL timing parameters for fast mode or fast mode plus. Only
* difference is the timing parameter values since the registers are
* the same.
*/
if (dev->clk_freq == 1000000) {
/*
* Check are fast mode plus parameters available and use
* fast mode if not.
*/
if (dev->fp_hcnt && dev->fp_lcnt) {
dev->fs_hcnt = dev->fp_hcnt;
dev->fs_lcnt = dev->fp_lcnt;
#if (TRACE_LEVEL >= TRACE_LEVEL_DEBUG)
fp_str = " Plus";
#endif
}
}
/*
* Calculate SCL timing parameters for fast mode if not set. They are
* needed also in high speed mode.
*/
if (!dev->fs_hcnt || !dev->fs_lcnt) {
ic_clk = i2c_dw_clk_rate(dev);
dev->fs_hcnt =
i2c_dw_scl_hcnt(ic_clk,
600, /* tHD;STA = tHIGH = 0.6 us */
sda_falling_time,
0, /* 0: DW default, 1: Ideal */
0); /* No offset */
dev->fs_lcnt =
i2c_dw_scl_lcnt(ic_clk,
1300, /* tLOW = 1.3 us */
scl_falling_time,
0); /* No offset */
}
TRACE_DEBUG("Fast Mode%s HCNT:LCNT = %d:%d\n", fp_str, dev->fs_hcnt, dev->fs_lcnt);
/* Check is high speed possible and fall back to fast mode if not */
if ((dev->master_cfg & DW_IC_CON_SPEED_MASK) ==
DW_IC_CON_SPEED_HIGH) {
if ((comp_param1 & DW_IC_COMP_PARAM_1_SPEED_MODE_MASK)
!= DW_IC_COMP_PARAM_1_SPEED_MODE_HIGH) {
TRACE_ERROR("High Speed not supported!\n");
dev->master_cfg &= ~DW_IC_CON_SPEED_MASK;
dev->master_cfg |= DW_IC_CON_SPEED_FAST;
dev->hs_hcnt = 0;
dev->hs_lcnt = 0;
} else if (dev->hs_hcnt && dev->hs_lcnt) {
TRACE_DEBUG("High Speed Mode HCNT:LCNT = %d:%d\n", dev->hs_hcnt, dev->hs_lcnt);
}
}
ret = i2c_dw_set_sda_hold(dev);
if (ret)
goto out;
#if (TRACE_LEVEL >= TRACE_LEVEL_DEBUG)
switch (dev->master_cfg & DW_IC_CON_SPEED_MASK) {
case DW_IC_CON_SPEED_STD:
mode_str = "Standard Mode";
break;
case DW_IC_CON_SPEED_HIGH:
mode_str = "High Speed Mode";
break;
default:
mode_str = "Fast Mode";
}
#endif
TRACE_DEBUG("Bus speed: %s%s\n", mode_str, fp_str);
out:
return ret;
}
/**
* i2c_dw_init() - Initialize the designware I2C master hardware
* @dev: device private data
*
* This functions configures and enables the I2C master.
* This function is called during I2C init function, and in case of timeout at
* run time.
*/
static int i2c_dw_init_master(struct dw_i2c_dev *dev)
{
int ret;
ret = i2c_dw_acquire_lock(dev);
if (ret)
return ret;
/* Disable the adapter */
__i2c_dw_disable(dev);
/* Write standard speed timing parameters */
dw_writel(dev, dev->ss_hcnt, DW_IC_SS_SCL_HCNT);
dw_writel(dev, dev->ss_lcnt, DW_IC_SS_SCL_LCNT);
/* Write fast mode/fast mode plus timing parameters */
dw_writel(dev, dev->fs_hcnt, DW_IC_FS_SCL_HCNT);
dw_writel(dev, dev->fs_lcnt, DW_IC_FS_SCL_LCNT);
/* Write high speed timing parameters if supported */
if (dev->hs_hcnt && dev->hs_lcnt) {
dw_writel(dev, dev->hs_hcnt, DW_IC_HS_SCL_HCNT);
dw_writel(dev, dev->hs_lcnt, DW_IC_HS_SCL_LCNT);
}
/* Write SDA hold time if supported */
if (dev->sda_hold_time)
dw_writel(dev, dev->sda_hold_time, DW_IC_SDA_HOLD);
i2c_dw_configure_fifo_master(dev);
i2c_dw_release_lock(dev);
return 0;
}
static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
{
struct i2c_msg *msgs = dev->msgs;
u32 ic_con, ic_tar = 0;
/* Disable the adapter */
__i2c_dw_disable(dev);
/* If the slave address is ten bit address, enable 10BITADDR */
ic_con = dw_readl(dev, DW_IC_CON);
if (msgs[dev->msg_write_idx].flags & I2C_M_TEN) {
ic_con |= DW_IC_CON_10BITADDR_MASTER;
/*
* If I2C_DYNAMIC_TAR_UPDATE is set, the 10-bit addressing
* mode has to be enabled via bit 12 of IC_TAR register.
* We set it always as I2C_DYNAMIC_TAR_UPDATE can't be
* detected from registers.
*/
ic_tar = DW_IC_TAR_10BITADDR_MASTER;
} else {
ic_con &= ~DW_IC_CON_10BITADDR_MASTER;
}
dw_writel(dev, ic_con, DW_IC_CON);
/*
* Set the slave (target) address and enable 10-bit addressing mode
* if applicable.
*/
dw_writel(dev, msgs[dev->msg_write_idx].addr | ic_tar, DW_IC_TAR);
/* Enforce disabled interrupts (due to HW issues) */
i2c_dw_disable_int(dev);
/* Enable the adapter */
__i2c_dw_enable(dev);
/* Dummy read to avoid the register getting stuck on Bay Trail */
dw_readl(dev, DW_IC_ENABLE_STATUS);
/* Clear and enable interrupts */
dw_readl(dev, DW_IC_CLR_INTR);
dw_writel(dev, DW_IC_INTR_MASTER_MASK, DW_IC_INTR_MASK);
}
/*
* Initiate (and continue) low level master read/write transaction.
* This function is only called from i2c_dw_isr, and pumping i2c_msg
* messages into the tx buffer. Even if the size of i2c_msg data is
* longer than the size of the tx buffer, it handles everything.
*/
static void
i2c_dw_xfer_msg(struct dw_i2c_dev *dev)
{
struct i2c_msg *msgs = dev->msgs;
u32 intr_mask;
int tx_limit, rx_limit;
u32 addr = msgs[dev->msg_write_idx].addr;
u32 buf_len = dev->tx_buf_len;
u8 *buf = dev->tx_buf;
int need_restart = 0;
intr_mask = DW_IC_INTR_MASTER_MASK;
for (; dev->msg_write_idx < dev->msgs_num; dev->msg_write_idx++) {
u32 flags = msgs[dev->msg_write_idx].flags;
/*
* If target address has changed, we need to
* reprogram the target address in the I2C
* adapter when we are done with this transfer.
*/
if (msgs[dev->msg_write_idx].addr != addr) {
TRACE_ERROR("%s: invalid target address\n", __func__);
dev->msg_err = -EINVAL;
break;
}
if (msgs[dev->msg_write_idx].len == 0) {
TRACE_ERROR("%s: invalid message length\n", __func__);
dev->msg_err = -EINVAL;
break;
}
if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) {
/* new i2c_msg */
buf = msgs[dev->msg_write_idx].buf;
buf_len = msgs[dev->msg_write_idx].len;
/* If both IC_EMPTYFIFO_HOLD_MASTER_EN and
* IC_RESTART_EN are set, we must manually
* set restart bit between messages.
*/
if ((dev->master_cfg & DW_IC_CON_RESTART_EN) &&
(dev->msg_write_idx > 0))
need_restart = 1;
}
tx_limit = dev->tx_fifo_depth - dw_readl(dev, DW_IC_TXFLR);
rx_limit = dev->rx_fifo_depth - dw_readl(dev, DW_IC_RXFLR);
while (buf_len > 0 && tx_limit > 0 && rx_limit > 0) {
u32 cmd = 0;
/*
* If IC_EMPTYFIFO_HOLD_MASTER_EN is set we must
* manually set the stop bit. However, it cannot be
* detected from the registers so we set it always
* when writing/reading the last byte.
*/
/*
* i2c-core always sets the buffer length of
* I2C_FUNC_SMBUS_BLOCK_DATA to 1. The length will
* be adjusted when receiving the first byte.
* Thus we can't stop the transaction here.
*/
if (dev->msg_write_idx == dev->msgs_num - 1 &&
buf_len == 1 && !(flags & I2C_M_RECV_LEN))
cmd |= BIT(9);
if (need_restart) {
cmd |= BIT(10);
need_restart = 0;
}
if (msgs[dev->msg_write_idx].flags & I2C_M_RD) {
/* Avoid rx buffer overrun */
if (dev->rx_outstanding >= dev->rx_fifo_depth)
break;
dw_writel(dev, cmd | 0x100, DW_IC_DATA_CMD);
rx_limit--;
dev->rx_outstanding++;
} else
dw_writel(dev, cmd | *buf++, DW_IC_DATA_CMD);
tx_limit--; buf_len--;
}
dev->tx_buf = buf;
dev->tx_buf_len = buf_len;
/*
* Because we don't know the buffer length in the
* I2C_FUNC_SMBUS_BLOCK_DATA case, we can't stop
* the transaction here.
*/
if (buf_len > 0 || flags & I2C_M_RECV_LEN) {
/* more bytes to be written */
dev->status |= STATUS_WRITE_IN_PROGRESS;
break;
} else
dev->status &= ~STATUS_WRITE_IN_PROGRESS;
}
/*
* If i2c_msg index search is completed, we don't need TX_EMPTY
* interrupt any more.
*/
if (dev->msg_write_idx == dev->msgs_num)
intr_mask &= ~DW_IC_INTR_TX_EMPTY;
if (dev->msg_err)
intr_mask = 0;
dw_writel(dev, intr_mask, DW_IC_INTR_MASK);
}
static u8
i2c_dw_recv_len(struct dw_i2c_dev *dev, u8 len)
{
struct i2c_msg *msgs = dev->msgs;
u32 flags = msgs[dev->msg_read_idx].flags;
/*
* Adjust the buffer length and mask the flag
* after receiving the first byte.
*/
len += (flags & I2C_CLIENT_PEC) ? 2 : 1;
dev->tx_buf_len = len - min(len, dev->rx_outstanding);
msgs[dev->msg_read_idx].len = len;
msgs[dev->msg_read_idx].flags &= ~I2C_M_RECV_LEN;
return len;
}
static void
i2c_dw_read(struct dw_i2c_dev *dev)
{
struct i2c_msg *msgs = dev->msgs;
int rx_valid;
for (; dev->msg_read_idx < dev->msgs_num; dev->msg_read_idx++) {
u32 len;
u8 *buf;
if (!(msgs[dev->msg_read_idx].flags & I2C_M_RD))
continue;
if (!(dev->status & STATUS_READ_IN_PROGRESS)) {
len = msgs[dev->msg_read_idx].len;
buf = msgs[dev->msg_read_idx].buf;
} else {
len = dev->rx_buf_len;
buf = dev->rx_buf;
}
rx_valid = dw_readl(dev, DW_IC_RXFLR);
for (; len > 0 && rx_valid > 0; len--, rx_valid--) {
u32 flags = msgs[dev->msg_read_idx].flags;
*buf = dw_readl(dev, DW_IC_DATA_CMD);
/* Ensure length byte is a valid value */
if (flags & I2C_M_RECV_LEN &&
*buf <= I2C_SMBUS_BLOCK_MAX && *buf > 0) {
len = i2c_dw_recv_len(dev, *buf);
}
buf++;
dev->rx_outstanding--;
}
if (len > 0) {
dev->status |= STATUS_READ_IN_PROGRESS;
dev->rx_buf_len = len;
dev->rx_buf = buf;
return;
} else
dev->status &= ~STATUS_READ_IN_PROGRESS;
}
}
/*
* Prepare controller for a transaction and call i2c_dw_xfer_msg.
*/
static int
i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
{
struct dw_i2c_dev *dev = adap->dw_dev;
int ret;
xQueueReset(dev->cmd_complete);
dev->msgs = msgs;
dev->msgs_num = num;
dev->cmd_err = 0;
dev->msg_write_idx = 0;
dev->msg_read_idx = 0;
dev->msg_err = 0;
dev->status = STATUS_IDLE;
dev->abort_source = 0;
dev->rx_outstanding = 0;
ret = i2c_dw_acquire_lock(dev);
if (ret)
goto done_nolock;
ret = i2c_dw_wait_bus_not_busy(dev);
if (ret < 0)
goto done;
/* Start the transfers */
i2c_dw_xfer_init(dev);
/* Wait for tx to complete */
if (!xQueueReceive(dev->cmd_complete, NULL, adap->timeout)) {
TRACE_ERROR("controller timed out\n");
/* i2c_dw_init implicitly disables the adapter */
i2c_dw_init_master(dev);
ret = -ETIMEDOUT;
goto done;
}
/*
* We must disable the adapter before returning and signaling the end
* of the current transfer. Otherwise the hardware might continue
* generating interrupts which in turn causes a race condition with
* the following transfer. Needs some more investigation if the
* additional interrupts are a hardware bug or this driver doesn't
* handle them correctly yet.
*/
__i2c_dw_disable_nowait(dev);
if (dev->msg_err) {
ret = dev->msg_err;
goto done;
}
/* No error */
if (!dev->cmd_err && !dev->status) {
ret = num;
goto done;
}
/* We have an error */
if (dev->cmd_err == DW_IC_ERR_TX_ABRT) {
ret = i2c_dw_handle_tx_abort(dev);
goto done;
}
if (dev->status)
TRACE_ERROR("transfer terminated early - interrupt latency too high?\n");
ret = -EIO;
done:
i2c_dw_release_lock(dev);
done_nolock:
return ret;
}
static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
{
return ulClkGetRate(CLK_XTAL24M) / 1000;
}
static void i2c_dw_configure_master(struct dw_i2c_dev *dev)
{
dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY;
dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
DW_IC_CON_RESTART_EN;
dev->mode = DW_IC_MASTER;
switch (dev->clk_freq) {
case 100000:
dev->master_cfg |= DW_IC_CON_SPEED_STD;
break;
case 3400000:
dev->master_cfg |= DW_IC_CON_SPEED_HIGH;
break;
default:
dev->master_cfg |= DW_IC_CON_SPEED_FAST;
}
}
#if defined(I2C0_SLAVE_MODE) || defined(I2C1_SLAVE_MODE)
static void i2c_dw_configure_slave(struct dw_i2c_dev *dev)
{
dev->functionality = I2C_FUNC_SLAVE | DW_IC_DEFAULT_FUNCTIONALITY;
dev->slave_cfg = DW_IC_CON_RX_FIFO_FULL_HLD_CTRL |
DW_IC_CON_RESTART_EN | DW_IC_CON_STOP_DET_IFADDRESSED;
dev->mode = DW_IC_SLAVE;
}
#endif
static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev)
{
u32 param, tx_fifo_depth, rx_fifo_depth;
/*
* Try to detect the FIFO depth if not set by interface driver,
* the depth could be from 2 to 256 from HW spec.
*/
param = i2c_dw_read_comp_param(dev);
tx_fifo_depth = ((param >> 16) & 0xff) + 1;
rx_fifo_depth = ((param >> 8) & 0xff) + 1;
if (!dev->tx_fifo_depth) {
dev->tx_fifo_depth = tx_fifo_depth;
dev->rx_fifo_depth = rx_fifo_depth;
} else if (tx_fifo_depth >= 2) {
dev->tx_fifo_depth = min(dev->tx_fifo_depth,
tx_fifo_depth);
dev->rx_fifo_depth = min(dev->rx_fifo_depth,
rx_fifo_depth);
}
}
static u32 i2c_dw_read_clear_intrbits(struct dw_i2c_dev *dev)
{
u32 stat;
/*
* The IC_INTR_STAT register just indicates "enabled" interrupts.
* Ths unmasked raw version of interrupt status bits are available
* in the IC_RAW_INTR_STAT register.
*
* That is,
* stat = dw_readl(IC_INTR_STAT);
* equals to,
* stat = dw_readl(IC_RAW_INTR_STAT) & dw_readl(IC_INTR_MASK);
*
* The raw version might be useful for debugging purposes.
*/
stat = dw_readl(dev, DW_IC_INTR_STAT);
/*
* Do not use the IC_CLR_INTR register to clear interrupts, or
* you'll miss some interrupts, triggered during the period from
* dw_readl(IC_INTR_STAT) to dw_readl(IC_CLR_INTR).
*
* Instead, use the separately-prepared IC_CLR_* registers.
*/
if (stat & DW_IC_INTR_RX_UNDER)
dw_readl(dev, DW_IC_CLR_RX_UNDER);
if (stat & DW_IC_INTR_RX_OVER)
dw_readl(dev, DW_IC_CLR_RX_OVER);
if (stat & DW_IC_INTR_TX_OVER)
dw_readl(dev, DW_IC_CLR_TX_OVER);
if (stat & DW_IC_INTR_RD_REQ)
dw_readl(dev, DW_IC_CLR_RD_REQ);
if (stat & DW_IC_INTR_TX_ABRT) {
/*
* The IC_TX_ABRT_SOURCE register is cleared whenever
* the IC_CLR_TX_ABRT is read. Preserve it beforehand.
*/
dev->abort_source = dw_readl(dev, DW_IC_TX_ABRT_SOURCE);
dw_readl(dev, DW_IC_CLR_TX_ABRT);
}
if (stat & DW_IC_INTR_RX_DONE)
dw_readl(dev, DW_IC_CLR_RX_DONE);
if (stat & DW_IC_INTR_ACTIVITY)
dw_readl(dev, DW_IC_CLR_ACTIVITY);
if (stat & DW_IC_INTR_STOP_DET)
dw_readl(dev, DW_IC_CLR_STOP_DET);
if (stat & DW_IC_INTR_START_DET)
dw_readl(dev, DW_IC_CLR_START_DET);
if (stat & DW_IC_INTR_GEN_CALL)
dw_readl(dev, DW_IC_CLR_GEN_CALL);
return stat;
}
/*
* Interrupt service routine. This gets called whenever an I2C master interrupt
* occurs.
*/
static int i2c_dw_irq_handler_master(struct dw_i2c_dev *dev)
{
u32 stat;
stat = i2c_dw_read_clear_intrbits(dev);
if (stat & DW_IC_INTR_TX_ABRT) {
dev->cmd_err |= DW_IC_ERR_TX_ABRT;
dev->status = STATUS_IDLE;
/*
* Anytime TX_ABRT is set, the contents of the tx/rx
* buffers are flushed. Make sure to skip them.
*/
dw_writel(dev, 0, DW_IC_INTR_MASK);
goto tx_aborted;
}
if (stat & DW_IC_INTR_RX_FULL)
i2c_dw_read(dev);
if (stat & DW_IC_INTR_TX_EMPTY)
i2c_dw_xfer_msg(dev);
/*
* No need to modify or disable the interrupt mask here.
* i2c_dw_xfer_msg() will take care of it according to
* the current transmit status.
*/
tx_aborted:
if ((stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET)) || dev->msg_err)
xQueueSendFromISR(dev->cmd_complete, NULL, 0);
else if (dev->flags & ACCESS_INTR_MASK) {
/* Workaround to trigger pending interrupt */
stat = dw_readl(dev, DW_IC_INTR_MASK);
i2c_dw_disable_int(dev);
dw_writel(dev, stat, DW_IC_INTR_MASK);
}
return 0;
}
static void i2c_dw_isr(void *dev_id)
{
struct dw_i2c_dev *dev = dev_id;
u32 stat, enabled;
enabled = dw_readl(dev, DW_IC_ENABLE);
stat = dw_readl(dev, DW_IC_RAW_INTR_STAT);
TRACE_DEBUG("enabled=%#x stat=%#x\n", enabled, stat);
if (!enabled || !(stat & ~DW_IC_INTR_ACTIVITY))
return;
i2c_dw_irq_handler_master(dev);
}
static const struct i2c_algorithm i2c_dw_algo = {
.master_xfer = i2c_dw_xfer,
};
static void i2c_dw_configure_fifo_slave(struct dw_i2c_dev *dev)
{
/* Configure Tx/Rx FIFO threshold levels. */
dw_writel(dev, 0, DW_IC_TX_TL);
dw_writel(dev, 0, DW_IC_RX_TL);
/* Configure the I2C slave. */
dw_writel(dev, dev->slave_cfg, DW_IC_CON);
dw_writel(dev, DW_IC_INTR_SLAVE_MASK, DW_IC_INTR_MASK);
}
/**
* i2c_dw_init_slave() - Initialize the designware i2c slave hardware
* @dev: device private data
*
* This function configures and enables the I2C in slave mode.
* This function is called during I2C init function, and in case of timeout at
* run time.
*/
static int i2c_dw_init_slave(struct dw_i2c_dev *dev)
{
int ret;
ret = i2c_dw_acquire_lock(dev);
if (ret)
return ret;
/* Disable the adapter. */
__i2c_dw_disable(dev);
/* Write SDA hold time if supported */
if (dev->sda_hold_time)
dw_writel(dev, dev->sda_hold_time, DW_IC_SDA_HOLD);
i2c_dw_configure_fifo_slave(dev);
i2c_dw_release_lock(dev);
return 0;
}
static int i2c_dw_reg_slave(struct i2c_adapter *slave)
{
struct dw_i2c_dev *dev = slave->dw_dev;
if (dev->slave)
return -EBUSY;
if (slave->flags & I2C_CLIENT_TEN)
return -ENOTSUP;
/*
* Set slave address in the IC_SAR register,
* the address to which the DW_apb_i2c responds.
*/
__i2c_dw_disable_nowait(dev);
dw_writel(dev, slave->addr, DW_IC_SAR);
dev->slave = slave;
__i2c_dw_enable(dev);
dev->cmd_err = 0;
dev->msg_write_idx = 0;
dev->msg_read_idx = 0;
dev->msg_err = 0;
dev->status = STATUS_IDLE;
dev->abort_source = 0;
dev->rx_outstanding = 0;
return 0;
}
static int i2c_dw_unreg_slave(struct i2c_adapter *slave)
{
struct dw_i2c_dev *dev = slave->dw_dev;
dev->disable_int(dev);
dev->disable(dev);
dev->slave = NULL;
return 0;
}
static u32 i2c_dw_read_clear_intrbits_slave(struct dw_i2c_dev *dev)
{
u32 stat;
/*
* The IC_INTR_STAT register just indicates "enabled" interrupts.
* Ths unmasked raw version of interrupt status bits are available
* in the IC_RAW_INTR_STAT register.
*
* That is,
* stat = dw_readl(IC_INTR_STAT);
* equals to,
* stat = dw_readl(IC_RAW_INTR_STAT) & dw_readl(IC_INTR_MASK);
*
* The raw version might be useful for debugging purposes.
*/
stat = dw_readl(dev, DW_IC_INTR_STAT);
/*
* Do not use the IC_CLR_INTR register to clear interrupts, or
* you'll miss some interrupts, triggered during the period from
* dw_readl(IC_INTR_STAT) to dw_readl(IC_CLR_INTR).
*
* Instead, use the separately-prepared IC_CLR_* registers.
*/
if (stat & DW_IC_INTR_TX_ABRT)
dw_readl(dev, DW_IC_CLR_TX_ABRT);
if (stat & DW_IC_INTR_RX_UNDER)
dw_readl(dev, DW_IC_CLR_RX_UNDER);
if (stat & DW_IC_INTR_RX_OVER)
dw_readl(dev, DW_IC_CLR_RX_OVER);
if (stat & DW_IC_INTR_TX_OVER)
dw_readl(dev, DW_IC_CLR_TX_OVER);
if (stat & DW_IC_INTR_RX_DONE)
dw_readl(dev, DW_IC_CLR_RX_DONE);
if (stat & DW_IC_INTR_ACTIVITY)
dw_readl(dev, DW_IC_CLR_ACTIVITY);
if (stat & DW_IC_INTR_STOP_DET)
dw_readl(dev, DW_IC_CLR_STOP_DET);
if (stat & DW_IC_INTR_START_DET)
dw_readl(dev, DW_IC_CLR_START_DET);
if (stat & DW_IC_INTR_GEN_CALL)
dw_readl(dev, DW_IC_CLR_GEN_CALL);
return stat;
}
/*
* Interrupt service routine. This gets called whenever an I2C slave interrupt
* occurs.
*/
static int i2c_dw_irq_handler_slave(struct dw_i2c_dev *dev)
{
u32 raw_stat, stat, enabled;
u8 val, slave_activity;
stat = dw_readl(dev, DW_IC_INTR_STAT);
enabled = dw_readl(dev, DW_IC_ENABLE);
raw_stat = dw_readl(dev, DW_IC_RAW_INTR_STAT);
slave_activity = ((dw_readl(dev, DW_IC_STATUS) &
DW_IC_STATUS_SLAVE_ACTIVITY) >> 6);
if (!enabled || !(raw_stat & ~DW_IC_INTR_ACTIVITY) || !dev->slave)
return 0;
TRACE_DEBUG("%#x STATUS SLAVE_ACTIVITY=%#x : RAW_INTR_STAT=%#x : INTR_STAT=%#x\n",
enabled, slave_activity, raw_stat, stat);
if ((stat & DW_IC_INTR_RX_FULL) && (stat & DW_IC_INTR_STOP_DET))
i2c_slave_event(dev->slave, I2C_SLAVE_WRITE_REQUESTED, &val);
if (stat & DW_IC_INTR_RD_REQ) {
if (slave_activity) {
if (stat & DW_IC_INTR_RX_FULL) {
val = dw_readl(dev, DW_IC_DATA_CMD);
if (!i2c_slave_event(dev->slave,
I2C_SLAVE_WRITE_RECEIVED,
&val)) {
TRACE_DEBUG("Byte %X acked!", val);
}
dw_readl(dev, DW_IC_CLR_RD_REQ);
stat = i2c_dw_read_clear_intrbits_slave(dev);
} else {
dw_readl(dev, DW_IC_CLR_RD_REQ);
dw_readl(dev, DW_IC_CLR_RX_UNDER);
stat = i2c_dw_read_clear_intrbits_slave(dev);
}
if (!i2c_slave_event(dev->slave,
I2C_SLAVE_READ_REQUESTED,
&val))
dw_writel(dev, val, DW_IC_DATA_CMD);
}
}
if (stat & DW_IC_INTR_RX_DONE) {
if (!i2c_slave_event(dev->slave, I2C_SLAVE_READ_PROCESSED,
&val))
dw_readl(dev, DW_IC_CLR_RX_DONE);
i2c_slave_event(dev->slave, I2C_SLAVE_STOP, &val);
stat = i2c_dw_read_clear_intrbits_slave(dev);
return 1;
}
if (stat & DW_IC_INTR_RX_FULL) {
val = dw_readl(dev, DW_IC_DATA_CMD);
if (!i2c_slave_event(dev->slave, I2C_SLAVE_WRITE_RECEIVED,
&val))
TRACE_DEBUG("Byte %X acked!", val);
} else {
i2c_slave_event(dev->slave, I2C_SLAVE_STOP, &val);
stat = i2c_dw_read_clear_intrbits_slave(dev);
}
return 1;
}
static void i2c_dw_isr_slave(void *dev_id)
{
struct dw_i2c_dev *dev = dev_id;
int ret;
i2c_dw_read_clear_intrbits_slave(dev);
ret = i2c_dw_irq_handler_slave(dev);
if (ret > 0)
xQueueSendFromISR(dev->cmd_complete, NULL, 0);
}
static const struct i2c_algorithm i2c_dw_slave_algo = {
.reg_slave = i2c_dw_reg_slave,
.unreg_slave = i2c_dw_unreg_slave,
};
int i2c_dw_init(int id)
{
struct i2c_adapter *adap;
struct dw_i2c_dev *dev;
int ret;
dev = pvPortMalloc(sizeof(struct dw_i2c_dev));
if (!dev) {
TRACE_ERROR("[%s] pvPortMalloc failed\n", __func__);
return -1;
}
memset(dev, 0, sizeof(struct dw_i2c_dev));
dev->cmd_complete = xQueueCreate(1, 0);
if(id == 0) {
dev->base = REGS_IIC0_BASE;
dev->irq = I2C0_IRQn;
dev->clk_freq = 100000;
sys_soft_reset(softreset_i2c);
#ifdef I2C0_SLAVE_MODE
i2c_dw_configure_slave(dev);
#else
i2c_dw_configure_master(dev);
#endif
} else if(id == 1) {
dev->base = REGS_IIC1_BASE;
dev->irq = I2C1_IRQn;
dev->clk_freq = 100000;
sys_soft_reset(softreset_i2c1);
#ifdef I2C1_SLAVE_MODE
i2c_dw_configure_slave(dev);
#else
i2c_dw_configure_master(dev);
#endif
} else {
TRACE_ERROR("[%s] Invalid id:%d\n", __func__, id);
ret = -1;
goto exit;
}
dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
dw_i2c_set_fifo_size(dev);
adap = &dev->adapter;
if (dev->mode == DW_IC_MASTER) {
dev->init = i2c_dw_init_master;
dev->disable = i2c_dw_disable;
dev->disable_int = i2c_dw_disable_int;
ret = i2c_dw_set_reg_access(dev);
if (ret) {
TRACE_ERROR("[%s] i2c_dw_set_reg_access failed, id:%d\n", __func__, id);
goto exit;
}
ret = i2c_dw_set_timings_master(dev);
if (ret) {
TRACE_ERROR("[%s] i2c_dw_set_timings_master failed, id:%d\n", __func__, id);
goto exit;
}
ret = dev->init(dev);
if (ret) {
TRACE_ERROR("[%s] dev->init failed, id:%d\n", __func__, id);
goto exit;
}
adap->retries = 3;
adap->algo = &i2c_dw_algo;
i2c_dw_disable_int(dev);
request_irq(dev->irq, 0, i2c_dw_isr, dev);
} else {
dev->init = i2c_dw_init_slave;
dev->disable = i2c_dw_disable;
dev->disable_int = i2c_dw_disable_int;
ret = i2c_dw_set_reg_access(dev);
if (ret) {
TRACE_ERROR("[%s] i2c_dw_set_reg_access failed, id:%d\n", __func__, id);
goto exit;
}
ret = i2c_dw_set_sda_hold(dev);
if (ret) {
TRACE_ERROR("[%s] i2c_dw_set_sda_hold failed, id:%d\n", __func__, id);
goto exit;
}
ret = dev->init(dev);
if (ret) {
TRACE_ERROR("[%s] dev->init failed, id:%d\n", __func__, id);
goto exit;
}
adap->retries = 3;
adap->algo = &i2c_dw_slave_algo;
adap->flags |= I2C_CLIENT_SLAVE;
request_irq(dev->irq, 0, i2c_dw_isr_slave, dev);
}
adap->dw_dev = dev;
snprintf(adap->name, sizeof(adap->name), "i2c%d", id);
ret = i2c_add_adapter(adap);
if(ret) {
TRACE_ERROR("[%s] i2c_add_adapter failed, id:%d\n", __func__, id);
free_irq(dev->irq);
goto exit;
}
return 0;
exit:
if(dev)
vPortFree(dev);
return ret;
}
#endif
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