diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-at91.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-at91.c | 24 |
1 files changed, 14 insertions, 10 deletions
diff --git a/drivers/i2c/busses/i2c-at91.c b/drivers/i2c/busses/i2c-at91.c index f23372669f77..1bb97f658b47 100644 --- a/drivers/i2c/busses/i2c-at91.c +++ b/drivers/i2c/busses/i2c-at91.c @@ -38,6 +38,7 @@ #define AT91_I2C_TIMEOUT msecs_to_jiffies(100) /* transfer timeout */ #define AT91_I2C_DMA_THRESHOLD 8 /* enable DMA if transfer size is bigger than this threshold */ #define AUTOSUSPEND_TIMEOUT 2000 +#define AT91_I2C_MAX_ALT_CMD_DATA_SIZE 256 /* AT91 TWI register definitions */ #define AT91_TWI_CR 0x0000 /* Control Register */ @@ -141,6 +142,7 @@ struct at91_twi_dev { unsigned twi_cwgr_reg; struct at91_twi_pdata *pdata; bool use_dma; + bool use_alt_cmd; bool recv_len_abort; u32 fifo_size; struct at91_twi_dma dma; @@ -269,7 +271,7 @@ static void at91_twi_write_next_byte(struct at91_twi_dev *dev) /* send stop when last byte has been written */ if (--dev->buf_len == 0) - if (!dev->pdata->has_alt_cmd) + if (!dev->use_alt_cmd) at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_STOP); dev_dbg(dev->dev, "wrote 0x%x, to go %d\n", *dev->buf, dev->buf_len); @@ -292,7 +294,7 @@ static void at91_twi_write_data_dma_callback(void *data) * we just have to enable TXCOMP one. */ at91_twi_write(dev, AT91_TWI_IER, AT91_TWI_TXCOMP); - if (!dev->pdata->has_alt_cmd) + if (!dev->use_alt_cmd) at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_STOP); } @@ -410,7 +412,7 @@ static void at91_twi_read_next_byte(struct at91_twi_dev *dev) } /* send stop if second but last byte has been read */ - if (!dev->pdata->has_alt_cmd && dev->buf_len == 1) + if (!dev->use_alt_cmd && dev->buf_len == 1) at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_STOP); dev_dbg(dev->dev, "read 0x%x, to go %d\n", *dev->buf, dev->buf_len); @@ -426,7 +428,7 @@ static void at91_twi_read_data_dma_callback(void *data) dma_unmap_single(dev->dev, sg_dma_address(&dev->dma.sg[0]), dev->buf_len, DMA_FROM_DEVICE); - if (!dev->pdata->has_alt_cmd) { + if (!dev->use_alt_cmd) { /* The last two bytes have to be read without using dma */ dev->buf += dev->buf_len - 2; dev->buf_len = 2; @@ -443,7 +445,7 @@ static void at91_twi_read_data_dma(struct at91_twi_dev *dev) struct dma_chan *chan_rx = dma->chan_rx; size_t buf_len; - buf_len = (dev->pdata->has_alt_cmd) ? dev->buf_len : dev->buf_len - 2; + buf_len = (dev->use_alt_cmd) ? dev->buf_len : dev->buf_len - 2; dma->direction = DMA_FROM_DEVICE; /* Keep in mind that we won't use dma to read the last two bytes */ @@ -651,7 +653,7 @@ static int at91_do_twi_transfer(struct at91_twi_dev *dev) unsigned start_flags = AT91_TWI_START; /* if only one byte is to be read, immediately stop transfer */ - if (!has_alt_cmd && dev->buf_len <= 1 && + if (!dev->use_alt_cmd && dev->buf_len <= 1 && !(dev->msg->flags & I2C_M_RECV_LEN)) start_flags |= AT91_TWI_STOP; at91_twi_write(dev, AT91_TWI_CR, start_flags); @@ -745,7 +747,7 @@ static int at91_twi_xfer(struct i2c_adapter *adap, struct i2c_msg *msg, int num) int ret; unsigned int_addr_flag = 0; struct i2c_msg *m_start = msg; - bool is_read, use_alt_cmd = false; + bool is_read; dev_dbg(&adap->dev, "at91_xfer: processing %d messages:\n", num); @@ -768,14 +770,16 @@ static int at91_twi_xfer(struct i2c_adapter *adap, struct i2c_msg *msg, int num) at91_twi_write(dev, AT91_TWI_IADR, internal_address); } + dev->use_alt_cmd = false; is_read = (m_start->flags & I2C_M_RD); if (dev->pdata->has_alt_cmd) { - if (m_start->len > 0) { + if (m_start->len > 0 && + m_start->len < AT91_I2C_MAX_ALT_CMD_DATA_SIZE) { at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_ACMEN); at91_twi_write(dev, AT91_TWI_ACR, AT91_TWI_ACR_DATAL(m_start->len) | ((is_read) ? AT91_TWI_ACR_DIR : 0)); - use_alt_cmd = true; + dev->use_alt_cmd = true; } else { at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_ACMDIS); } @@ -784,7 +788,7 @@ static int at91_twi_xfer(struct i2c_adapter *adap, struct i2c_msg *msg, int num) at91_twi_write(dev, AT91_TWI_MMR, (m_start->addr << 16) | int_addr_flag | - ((!use_alt_cmd && is_read) ? AT91_TWI_MREAD : 0)); + ((!dev->use_alt_cmd && is_read) ? AT91_TWI_MREAD : 0)); dev->buf_len = m_start->len; dev->buf = m_start->buf; |