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-rw-r--r--drivers/i2c/busses/i2c-qup.c194
1 files changed, 110 insertions, 84 deletions
diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c
index 13c751e2dd9a..5bb7ebe70f3c 100644
--- a/drivers/i2c/busses/i2c-qup.c
+++ b/drivers/i2c/busses/i2c-qup.c
@@ -118,8 +118,12 @@
#define ONE_BYTE 0x1
#define QUP_I2C_MX_CONFIG_DURING_RUN BIT(31)
+/* Maximum transfer length for single DMA descriptor */
#define MX_TX_RX_LEN SZ_64K
#define MX_BLOCKS (MX_TX_RX_LEN / QUP_READ_LIMIT)
+/* Maximum transfer length for all DMA descriptors */
+#define MX_DMA_TX_RX_LEN (2 * MX_TX_RX_LEN)
+#define MX_DMA_BLOCKS (MX_DMA_TX_RX_LEN / QUP_READ_LIMIT)
/*
* Minimum transfer timeout for i2c transfers in seconds. It will be added on
@@ -150,6 +154,7 @@ struct qup_i2c_bam {
struct qup_i2c_tag tag;
struct dma_chan *dma;
struct scatterlist *sg;
+ unsigned int sg_cnt;
};
struct qup_i2c_dev {
@@ -188,6 +193,8 @@ struct qup_i2c_dev {
bool is_dma;
/* To check if the current transfer is using DMA */
bool use_dma;
+ unsigned int max_xfer_sg_len;
+ unsigned int tag_buf_pos;
struct dma_pool *dpool;
struct qup_i2c_tag start_tag;
struct qup_i2c_bam brx;
@@ -692,102 +699,87 @@ static int qup_i2c_req_dma(struct qup_i2c_dev *qup)
return 0;
}
-static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg,
- int num)
+static int qup_i2c_bam_make_desc(struct qup_i2c_dev *qup, struct i2c_msg *msg)
{
- struct dma_async_tx_descriptor *txd, *rxd = NULL;
- int ret = 0, idx = 0, limit = QUP_READ_LIMIT;
- dma_cookie_t cookie_rx, cookie_tx;
- u32 len, blocks, rem;
- u32 i, tlen, tx_len, tx_cnt = 0, rx_cnt = 0, off = 0;
+ int ret = 0, limit = QUP_READ_LIMIT;
+ u32 len = 0, blocks, rem;
+ u32 i = 0, tlen, tx_len = 0;
u8 *tags;
- while (idx < num) {
- tx_len = 0, len = 0, i = 0;
-
- qup->is_last = (idx == (num - 1));
+ qup_i2c_set_blk_data(qup, msg);
- qup_i2c_set_blk_data(qup, msg);
+ blocks = qup->blk.count;
+ rem = msg->len - (blocks - 1) * limit;
- blocks = qup->blk.count;
- rem = msg->len - (blocks - 1) * limit;
+ if (msg->flags & I2C_M_RD) {
+ while (qup->blk.pos < blocks) {
+ tlen = (i == (blocks - 1)) ? rem : limit;
+ tags = &qup->start_tag.start[qup->tag_buf_pos + len];
+ len += qup_i2c_set_tags(tags, qup, msg);
+ qup->blk.data_len -= tlen;
- if (msg->flags & I2C_M_RD) {
- while (qup->blk.pos < blocks) {
- tlen = (i == (blocks - 1)) ? rem : limit;
- tags = &qup->start_tag.start[off + len];
- len += qup_i2c_set_tags(tags, qup, msg);
- qup->blk.data_len -= tlen;
+ /* scratch buf to read the start and len tags */
+ ret = qup_sg_set_buf(&qup->brx.sg[qup->brx.sg_cnt++],
+ &qup->brx.tag.start[0],
+ 2, qup, DMA_FROM_DEVICE);
- /* scratch buf to read the start and len tags */
- ret = qup_sg_set_buf(&qup->brx.sg[rx_cnt++],
- &qup->brx.tag.start[0],
- 2, qup, DMA_FROM_DEVICE);
+ if (ret)
+ return ret;
- if (ret)
- return ret;
+ ret = qup_sg_set_buf(&qup->brx.sg[qup->brx.sg_cnt++],
+ &msg->buf[limit * i],
+ tlen, qup,
+ DMA_FROM_DEVICE);
+ if (ret)
+ return ret;
- ret = qup_sg_set_buf(&qup->brx.sg[rx_cnt++],
- &msg->buf[limit * i],
- tlen, qup,
- DMA_FROM_DEVICE);
- if (ret)
- return ret;
+ i++;
+ qup->blk.pos = i;
+ }
+ ret = qup_sg_set_buf(&qup->btx.sg[qup->btx.sg_cnt++],
+ &qup->start_tag.start[qup->tag_buf_pos],
+ len, qup, DMA_TO_DEVICE);
+ if (ret)
+ return ret;
- i++;
- qup->blk.pos = i;
- }
- ret = qup_sg_set_buf(&qup->btx.sg[tx_cnt++],
- &qup->start_tag.start[off],
- len, qup, DMA_TO_DEVICE);
+ qup->tag_buf_pos += len;
+ } else {
+ while (qup->blk.pos < blocks) {
+ tlen = (i == (blocks - 1)) ? rem : limit;
+ tags = &qup->start_tag.start[qup->tag_buf_pos + tx_len];
+ len = qup_i2c_set_tags(tags, qup, msg);
+ qup->blk.data_len -= tlen;
+
+ ret = qup_sg_set_buf(&qup->btx.sg[qup->btx.sg_cnt++],
+ tags, len,
+ qup, DMA_TO_DEVICE);
if (ret)
return ret;
- off += len;
- } else {
- while (qup->blk.pos < blocks) {
- tlen = (i == (blocks - 1)) ? rem : limit;
- tags = &qup->start_tag.start[off + tx_len];
- len = qup_i2c_set_tags(tags, qup, msg);
- qup->blk.data_len -= tlen;
-
- ret = qup_sg_set_buf(&qup->btx.sg[tx_cnt++],
- tags, len,
- qup, DMA_TO_DEVICE);
- if (ret)
- return ret;
-
- tx_len += len;
- ret = qup_sg_set_buf(&qup->btx.sg[tx_cnt++],
- &msg->buf[limit * i],
- tlen, qup, DMA_TO_DEVICE);
- if (ret)
- return ret;
- i++;
- qup->blk.pos = i;
- }
- off += tx_len;
-
- if (idx == (num - 1)) {
- len = 1;
- if (rx_cnt) {
- qup->btx.tag.start[0] =
- QUP_BAM_INPUT_EOT;
- len++;
- }
- qup->btx.tag.start[len - 1] =
- QUP_BAM_FLUSH_STOP;
- ret = qup_sg_set_buf(&qup->btx.sg[tx_cnt++],
- &qup->btx.tag.start[0],
- len, qup, DMA_TO_DEVICE);
- if (ret)
- return ret;
- }
+ tx_len += len;
+ ret = qup_sg_set_buf(&qup->btx.sg[qup->btx.sg_cnt++],
+ &msg->buf[limit * i],
+ tlen, qup, DMA_TO_DEVICE);
+ if (ret)
+ return ret;
+ i++;
+ qup->blk.pos = i;
}
- idx++;
- msg++;
+
+ qup->tag_buf_pos += tx_len;
}
+ return 0;
+}
+
+static int qup_i2c_bam_schedule_desc(struct qup_i2c_dev *qup)
+{
+ struct dma_async_tx_descriptor *txd, *rxd = NULL;
+ int ret = 0;
+ dma_cookie_t cookie_rx, cookie_tx;
+ u32 len = 0;
+ u32 tx_cnt = qup->btx.sg_cnt, rx_cnt = qup->brx.sg_cnt;
+
/* schedule the EOT and FLUSH I2C tags */
len = 1;
if (rx_cnt) {
@@ -886,11 +878,19 @@ desc_err:
return ret;
}
+static void qup_i2c_bam_clear_tag_buffers(struct qup_i2c_dev *qup)
+{
+ qup->btx.sg_cnt = 0;
+ qup->brx.sg_cnt = 0;
+ qup->tag_buf_pos = 0;
+}
+
static int qup_i2c_bam_xfer(struct i2c_adapter *adap, struct i2c_msg *msg,
int num)
{
struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
int ret = 0;
+ int idx = 0;
enable_irq(qup->irq);
ret = qup_i2c_req_dma(qup);
@@ -913,9 +913,34 @@ static int qup_i2c_bam_xfer(struct i2c_adapter *adap, struct i2c_msg *msg,
goto out;
writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL);
+ qup_i2c_bam_clear_tag_buffers(qup);
+
+ for (idx = 0; idx < num; idx++) {
+ qup->msg = msg + idx;
+ qup->is_last = idx == (num - 1);
+
+ ret = qup_i2c_bam_make_desc(qup, qup->msg);
+ if (ret)
+ break;
+
+ /*
+ * Make DMA descriptor and schedule the BAM transfer if its
+ * already crossed the maximum length. Since the memory for all
+ * tags buffers have been taken for 2 maximum possible
+ * transfers length so it will never cross the buffer actual
+ * length.
+ */
+ if (qup->btx.sg_cnt > qup->max_xfer_sg_len ||
+ qup->brx.sg_cnt > qup->max_xfer_sg_len ||
+ qup->is_last) {
+ ret = qup_i2c_bam_schedule_desc(qup);
+ if (ret)
+ break;
+
+ qup_i2c_bam_clear_tag_buffers(qup);
+ }
+ }
- qup->msg = msg;
- ret = qup_i2c_bam_do_xfer(qup, qup->msg, num);
out:
disable_irq(qup->irq);
@@ -1468,7 +1493,8 @@ static int qup_i2c_probe(struct platform_device *pdev)
else if (ret != 0)
goto nodma;
- blocks = (MX_BLOCKS << 1) + 1;
+ qup->max_xfer_sg_len = (MX_BLOCKS << 1);
+ blocks = (MX_DMA_BLOCKS << 1) + 1;
qup->btx.sg = devm_kzalloc(&pdev->dev,
sizeof(*qup->btx.sg) * blocks,
GFP_KERNEL);
@@ -1611,7 +1637,7 @@ nodma:
one_bit_t = (USEC_PER_SEC / clk_freq) + 1;
qup->one_byte_t = one_bit_t * 9;
qup->xfer_timeout = TOUT_MIN * HZ +
- usecs_to_jiffies(MX_TX_RX_LEN * qup->one_byte_t);
+ usecs_to_jiffies(MX_DMA_TX_RX_LEN * qup->one_byte_t);
dev_dbg(qup->dev, "IN:block:%d, fifo:%d, OUT:block:%d, fifo:%d\n",
qup->in_blk_sz, qup->in_fifo_sz,
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-21 04:21:37 +0000