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i2c: imx: separate atomic, dma and non-dma use case

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Separate the atomic, dma and non-dma use case as a preparation step for
moving the non-dma use case to the isr to avoid rescheduling while a
transfer is in progress.

Signed-off-by: Stefan Eichenberger <stefan.eichenberger@toradex.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
This commit is contained in:
Stefan Eichenberger
2024-10-14 15:15:13 +02:00
committed by Andi Shyti
parent 6692694aca
commit b460b15b3c
1 changed files with 70 additions and 37 deletions
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107
drivers/i2c/busses/i2c-imx.c
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@@ -1011,6 +1011,43 @@ static int i2c_imx_dma_write(struct imx_i2c_struct *i2c_imx,
return i2c_imx_acked(i2c_imx);
}
static int i2c_imx_prepare_read(struct imx_i2c_struct *i2c_imx,
struct i2c_msg *msgs, bool atomic,
bool use_dma)
{
int result;
unsigned int temp = 0;
/* write slave address */
imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR);
result = i2c_imx_trx_complete(i2c_imx, atomic);
if (result)
return result;
result = i2c_imx_acked(i2c_imx);
if (result)
return result;
dev_dbg(&i2c_imx->adapter.dev, "<%s> setup bus\n", __func__);
/* setup bus to read data */
temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
temp &= ~I2CR_MTX;
/*
* Reset the I2CR_TXAK flag initially for SMBus block read since the
* length is unknown
*/
if (msgs->len - 1)
temp &= ~I2CR_TXAK;
if (use_dma)
temp |= I2CR_DMAEN;
imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); /* dummy read */
return 0;
}
static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx,
struct i2c_msg *msgs, bool is_lastmsg)
{
@@ -1021,6 +1058,11 @@ static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx,
struct imx_i2c_dma *dma = i2c_imx->dma;
struct device *dev = &i2c_imx->adapter.dev;
result = i2c_imx_prepare_read(i2c_imx, msgs, false, true);
if (result)
return result;
dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__);
dma->chan_using = dma->chan_rx;
dma->dma_transfer_dir = DMA_DEV_TO_MEM;
@@ -1131,50 +1173,24 @@ static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs,
return 0;
}
static int i2c_imx_atomic_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
{
return i2c_imx_write(i2c_imx, msgs, true);
}
static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs,
bool is_lastmsg, bool atomic)
{
int i, result;
unsigned int temp;
int block_data = msgs->flags & I2C_M_RECV_LEN;
int use_dma = i2c_imx->dma && msgs->flags & I2C_M_DMA_SAFE &&
msgs->len >= DMA_THRESHOLD && !block_data;
dev_dbg(&i2c_imx->adapter.dev,
"<%s> write slave address: addr=0x%x\n",
__func__, i2c_8bit_addr_from_msg(msgs));
/* write slave address */
imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR);
result = i2c_imx_trx_complete(i2c_imx, atomic);
result = i2c_imx_prepare_read(i2c_imx, msgs, atomic, false);
if (result)
return result;
result = i2c_imx_acked(i2c_imx);
if (result)
return result;
dev_dbg(&i2c_imx->adapter.dev, "<%s> setup bus\n", __func__);
/* setup bus to read data */
temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
temp &= ~I2CR_MTX;
/*
* Reset the I2CR_TXAK flag initially for SMBus block read since the
* length is unknown
*/
if ((msgs->len - 1) || block_data)
temp &= ~I2CR_TXAK;
if (use_dma)
temp |= I2CR_DMAEN;
imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); /* dummy read */
dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__);
if (use_dma)
return i2c_imx_dma_read(i2c_imx, msgs, is_lastmsg);
/* read data */
for (i = 0; i < msgs->len; i++) {
u8 len = 0;
@@ -1241,6 +1257,12 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs,
return 0;
}
static int i2c_imx_atomic_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs,
bool is_lastmsg)
{
return i2c_imx_read(i2c_imx, msgs, is_lastmsg, true);
}
static int i2c_imx_xfer_common(struct i2c_adapter *adapter,
struct i2c_msg *msgs, int num, bool atomic)
{
@@ -1248,6 +1270,7 @@ static int i2c_imx_xfer_common(struct i2c_adapter *adapter,
int result;
bool is_lastmsg = false;
struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);
int use_dma = 0;
/* Start I2C transfer */
result = i2c_imx_start(i2c_imx, atomic);
@@ -1300,15 +1323,25 @@ static int i2c_imx_xfer_common(struct i2c_adapter *adapter,
(temp & I2SR_SRW ? 1 : 0), (temp & I2SR_IIF ? 1 : 0),
(temp & I2SR_RXAK ? 1 : 0));
#endif
use_dma = i2c_imx->dma && msgs[i].len >= DMA_THRESHOLD &&
msgs[i].flags & I2C_M_DMA_SAFE;
if (msgs[i].flags & I2C_M_RD) {
result = i2c_imx_read(i2c_imx, &msgs[i], is_lastmsg, atomic);
int block_data = msgs->flags & I2C_M_RECV_LEN;
if (atomic)
result = i2c_imx_atomic_read(i2c_imx, &msgs[i], is_lastmsg);
else if (use_dma && !block_data)
result = i2c_imx_dma_read(i2c_imx, &msgs[i], is_lastmsg);
else
result = i2c_imx_read(i2c_imx, &msgs[i], is_lastmsg, false);
} else {
if (!atomic &&
i2c_imx->dma && msgs[i].len >= DMA_THRESHOLD &&
msgs[i].flags & I2C_M_DMA_SAFE)
if (atomic)
result = i2c_imx_atomic_write(i2c_imx, &msgs[i]);
else if (use_dma)
result = i2c_imx_dma_write(i2c_imx, &msgs[i]);
else
result = i2c_imx_write(i2c_imx, &msgs[i], atomic);
result = i2c_imx_write(i2c_imx, &msgs[i], false);
}
if (result)
goto fail0;