@@ -14,8 +14,12 @@
*
*/
+#include <linux/atomic.h>
#include <linux/clk.h>
#include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/dmapool.h>
+#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
@@ -24,6 +28,7 @@
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
+#include <linux/scatterlist.h>
/* QUP Registers */
#define QUP_CONFIG 0x000
@@ -33,6 +38,7 @@
#define QUP_OPERATIONAL 0x018
#define QUP_ERROR_FLAGS 0x01c
#define QUP_ERROR_FLAGS_EN 0x020
+#define QUP_OPERATIONAL_MASK 0x028
#define QUP_HW_VERSION 0x030
#define QUP_MX_OUTPUT_CNT 0x100
#define QUP_OUT_FIFO_BASE 0x110
@@ -52,6 +58,7 @@
#define QUP_STATE_VALID BIT(2)
#define QUP_I2C_MAST_GEN BIT(4)
+#define QUP_I2C_FLUSH BIT(6)
#define QUP_OPERATIONAL_RESET 0x000ff0
#define QUP_I2C_STATUS_RESET 0xfffffc
@@ -77,7 +84,10 @@
/* Packing/Unpacking words in FIFOs, and IO modes */
#define QUP_OUTPUT_BLK_MODE (1 << 10)
+#define QUP_OUTPUT_BAM_MODE (3 << 10)
#define QUP_INPUT_BLK_MODE (1 << 12)
+#define QUP_INPUT_BAM_MODE (3 << 12)
+#define QUP_BAM_MODE (QUP_OUTPUT_BAM_MODE | QUP_INPUT_BAM_MODE)
#define QUP_UNPACK_EN BIT(14)
#define QUP_PACK_EN BIT(15)
@@ -94,6 +104,8 @@
#define QUP_TAG_DATA (2 << 8)
#define QUP_TAG_STOP (3 << 8)
#define QUP_TAG_REC (4 << 8)
+#define QUP_BAM_INPUT_EOT 0x93
+#define QUP_BAM_FLUSH_STOP 0x96
/* QUP v2 tags */
#define QUP_TAG_V2_START 0x81
@@ -114,6 +126,12 @@
#define ONE_BYTE 0x1
#define QUP_I2C_MX_CONFIG_DURING_RUN BIT(31)
+#define MX_TX_RX_LEN SZ_64K
+#define MX_BLOCKS (MX_TX_RX_LEN / QUP_READ_LIMIT)
+
+/* Max timeout in ms for 32k bytes */
+#define TOUT_MAX 300
+
struct qup_i2c_block {
int count;
int pos;
@@ -123,6 +141,17 @@ struct qup_i2c_block {
u8 tags[6];
};
+struct qup_i2c_tag {
+ u8 *start;
+ dma_addr_t addr;
+};
+
+struct qup_i2c_bam {
+ struct qup_i2c_tag tag;
+ struct dma_chan *dma;
+ struct scatterlist *sg;
+};
+
struct qup_i2c_dev {
struct device *dev;
void __iomem *base;
@@ -154,6 +183,13 @@ struct qup_i2c_dev {
/* To configure when bus is in run state */
int config_run;
+ /* dma parameters */
+ bool is_dma;
+ struct dma_pool *dpool;
+ struct qup_i2c_tag start_tag;
+ struct qup_i2c_bam brx;
+ struct qup_i2c_bam btx;
+
struct completion xfer;
};
@@ -230,6 +266,14 @@ static int qup_i2c_poll_state(struct qup_i2c_dev *qup, u32 req_state)
return qup_i2c_poll_state_mask(qup, req_state, QUP_STATE_MASK);
}
+static void qup_i2c_flush(struct qup_i2c_dev *qup)
+{
+ u32 val = readl(qup->base + QUP_STATE);
+
+ val |= QUP_I2C_FLUSH;
+ writel(val, qup->base + QUP_STATE);
+}
+
static int qup_i2c_poll_state_valid(struct qup_i2c_dev *qup)
{
return qup_i2c_poll_state_mask(qup, 0, 0);
@@ -437,12 +481,14 @@ static int qup_i2c_get_data_len(struct qup_i2c_dev *qup)
}
static int qup_i2c_set_tags(u8 *tags, struct qup_i2c_dev *qup,
- struct i2c_msg *msg)
+ struct i2c_msg *msg, int is_dma)
{
u16 addr = (msg->addr << 1) | ((msg->flags & I2C_M_RD) == I2C_M_RD);
int len = 0;
int data_len;
+ int last = (qup->blk.pos == (qup->blk.count - 1)) && (qup->is_last);
+
if (qup->blk.pos == 0) {
tags[len++] = QUP_TAG_V2_START;
tags[len++] = addr & 0xff;
@@ -452,7 +498,7 @@ static int qup_i2c_set_tags(u8 *tags, struct qup_i2c_dev *qup,
}
/* Send _STOP commands for the last block */
- if ((qup->blk.pos == (qup->blk.count - 1)) && qup->is_last) {
+ if (last) {
if (msg->flags & I2C_M_RD)
tags[len++] = QUP_TAG_V2_DATARD_STOP;
else
@@ -472,6 +518,11 @@ static int qup_i2c_set_tags(u8 *tags, struct qup_i2c_dev *qup,
else
tags[len++] = data_len;
+ if ((msg->flags & I2C_M_RD) && last && is_dma) {
+ tags[len++] = QUP_BAM_INPUT_EOT;
+ tags[len++] = QUP_BAM_FLUSH_STOP;
+ }
+
return len;
}
@@ -480,7 +531,7 @@ static int qup_i2c_issue_xfer_v2(struct qup_i2c_dev *qup, struct i2c_msg *msg)
int data_len = 0, tag_len, index;
int ret;
- tag_len = qup_i2c_set_tags(qup->blk.tags, qup, msg);
+ tag_len = qup_i2c_set_tags(qup->blk.tags, qup, msg, 0);
index = msg->len - qup->blk.data_len;
/* only tags are written for read */
@@ -494,6 +545,283 @@ static int qup_i2c_issue_xfer_v2(struct qup_i2c_dev *qup, struct i2c_msg *msg)
return ret;
}
+static void qup_i2c_bam_cb(void *data)
+{
+ struct qup_i2c_dev *qup = data;
+
+ complete(&qup->xfer);
+}
+
+void qup_sg_set_buf(struct scatterlist *sg, void *buf, struct qup_i2c_tag *tg,
+ unsigned int buflen, struct qup_i2c_dev *qup,
+ int map, int dir)
+{
+ sg_set_buf(sg, buf, buflen);
+ dma_map_sg(qup->dev, sg, 1, dir);
+
+ if (!map)
+ sg_dma_address(sg) = tg->addr + ((u8 *)buf - tg->start);
+}
+
+static void qup_i2c_rel_dma(struct qup_i2c_dev *qup)
+{
+ if (qup->btx.dma)
+ dma_release_channel(qup->btx.dma);
+ if (qup->brx.dma)
+ dma_release_channel(qup->brx.dma);
+ qup->btx.dma = NULL;
+ qup->brx.dma = NULL;
+}
+
+static int qup_i2c_req_dma(struct qup_i2c_dev *qup)
+{
+ int err;
+
+ if (!qup->btx.dma) {
+ qup->btx.dma = dma_request_slave_channel_reason(qup->dev, "tx");
+ if (IS_ERR(qup->btx.dma)) {
+ err = PTR_ERR(qup->btx.dma);
+ qup->btx.dma = NULL;
+ dev_err(qup->dev, "\n tx channel not available");
+ return err;
+ }
+ }
+
+ if (!qup->brx.dma) {
+ qup->brx.dma = dma_request_slave_channel_reason(qup->dev, "rx");
+ if (IS_ERR(qup->brx.dma)) {
+ dev_err(qup->dev, "\n rx channel not available");
+ err = PTR_ERR(qup->brx.dma);
+ qup->brx.dma = NULL;
+ qup_i2c_rel_dma(qup);
+ return err;
+ }
+ }
+ return 0;
+}
+
+static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg,
+ int num)
+{
+ struct dma_async_tx_descriptor *txd, *rxd = NULL;
+ int ret = 0, idx = 0;
+ dma_cookie_t cookie_rx, cookie_tx;
+ u32 rx_nents = 0, tx_nents = 0, len, blocks, rem;
+ u32 i, tlen, tx_len, tx_buf = 0, rx_buf = 0, off = 0;
+ u8 *tags;
+
+ while (idx < num) {
+ blocks = (msg->len + QUP_READ_LIMIT) / QUP_READ_LIMIT;
+ rem = msg->len % QUP_READ_LIMIT;
+ tx_len = 0, len = 0, i = 0;
+
+ qup->is_last = (idx == (num - 1));
+
+ qup_i2c_set_blk_data(qup, msg);
+
+ if (msg->flags & I2C_M_RD) {
+ rx_nents += (blocks * 2) + 1;
+ tx_nents += 1;
+
+ while (qup->blk.pos < blocks) {
+ /* length set to '0' implies 256 bytes */
+ tlen = (i == (blocks - 1)) ? rem : 0;
+ tags = &qup->start_tag.start[off + len];
+ len += qup_i2c_set_tags(tags, qup, msg, 1);
+
+ /* scratch buf to read the start and len tags */
+ qup_sg_set_buf(&qup->brx.sg[rx_buf++],
+ &qup->brx.tag.start[0],
+ &qup->brx.tag,
+ 2, qup, 0, 0);
+
+ qup_sg_set_buf(&qup->brx.sg[rx_buf++],
+ &msg->buf[QUP_READ_LIMIT * i],
+ NULL, tlen, qup,
+ 1, DMA_FROM_DEVICE);
+ i++;
+ qup->blk.pos = i;
+ }
+ qup_sg_set_buf(&qup->btx.sg[tx_buf++],
+ &qup->start_tag.start[off],
+ &qup->start_tag, len, qup, 0, 0);
+ off += len;
+ /* scratch buf to read the BAM EOT and FLUSH tags */
+ qup_sg_set_buf(&qup->brx.sg[rx_buf++],
+ &qup->brx.tag.start[0],
+ &qup->brx.tag, 2,
+ qup, 0, 0);
+ } else {
+ tx_nents += (blocks * 2);
+
+ while (qup->blk.pos < blocks) {
+ tlen = (i == (blocks - 1)) ? rem : 0;
+ tags = &qup->start_tag.start[off + tx_len];
+ len = qup_i2c_set_tags(tags, qup, msg, 1);
+
+ qup_sg_set_buf(&qup->btx.sg[tx_buf++],
+ tags,
+ &qup->start_tag, len,
+ qup, 0, 0);
+
+ tx_len += len;
+ qup_sg_set_buf(&qup->btx.sg[tx_buf++],
+ &msg->buf[QUP_READ_LIMIT * i],
+ NULL, tlen, qup, 1,
+ DMA_TO_DEVICE);
+ i++;
+ qup->blk.pos = i;
+ }
+ off += tx_len;
+
+ if (idx == (num - 1)) {
+ len = 1;
+ if (rx_nents) {
+ qup->btx.tag.start[0] =
+ QUP_BAM_INPUT_EOT;
+ len++;
+ }
+ qup->btx.tag.start[len - 1] =
+ QUP_BAM_FLUSH_STOP;
+ qup_sg_set_buf(&qup->btx.sg[tx_buf++],
+ &qup->btx.tag.start[0],
+ &qup->btx.tag, len,
+ qup, 0, 0);
+ tx_nents += 1;
+ }
+ }
+ idx++;
+ msg++;
+ }
+
+ txd = dmaengine_prep_slave_sg(qup->btx.dma, qup->btx.sg, tx_nents,
+ DMA_MEM_TO_DEV,
+ DMA_PREP_INTERRUPT | DMA_PREP_FENCE);
+ if (!txd) {
+ dev_err(qup->dev, "failed to get tx desc\n");
+ ret = -EINVAL;
+ goto desc_err;
+ }
+
+ if (!rx_nents) {
+ txd->callback = qup_i2c_bam_cb;
+ txd->callback_param = qup;
+ }
+
+ cookie_tx = dmaengine_submit(txd);
+ if (dma_submit_error(cookie_tx)) {
+ ret = -EINVAL;
+ goto desc_err;
+ }
+
+ dma_async_issue_pending(qup->btx.dma);
+
+ if (rx_nents) {
+ rxd = dmaengine_prep_slave_sg(qup->brx.dma, qup->brx.sg,
+ rx_nents, DMA_DEV_TO_MEM,
+ DMA_PREP_INTERRUPT);
+ if (!rxd) {
+ dev_err(qup->dev, "failed to get rx desc\n");
+ ret = -EINVAL;
+
+ /* abort TX descriptors */
+ dmaengine_terminate_all(qup->btx.dma);
+ goto desc_err;
+ }
+
+ rxd->callback = qup_i2c_bam_cb;
+ rxd->callback_param = qup;
+ cookie_rx = dmaengine_submit(rxd);
+ if (dma_submit_error(cookie_rx)) {
+ ret = -EINVAL;
+ goto desc_err;
+ }
+
+ dma_async_issue_pending(qup->brx.dma);
+ }
+
+ if (!wait_for_completion_timeout(&qup->xfer, TOUT_MAX * HZ)) {
+ dev_err(qup->dev, "normal trans timed out\n");
+ ret = -ETIMEDOUT;
+ }
+
+ if (ret || qup->bus_err || qup->qup_err) {
+ if (qup->bus_err & QUP_I2C_NACK_FLAG) {
+ msg--;
+ dev_err(qup->dev, "NACK from %x\n", msg->addr);
+ ret = -EIO;
+
+ if (qup_i2c_change_state(qup, QUP_RUN_STATE)) {
+ dev_err(qup->dev, "change to run state timed out");
+ return ret;
+ }
+
+ if (rx_nents)
+ writel(QUP_BAM_INPUT_EOT,
+ qup->base + QUP_OUT_FIFO_BASE);
+
+ writel(QUP_BAM_FLUSH_STOP,
+ qup->base + QUP_OUT_FIFO_BASE);
+
+ qup_i2c_flush(qup);
+
+ /* wait for remaining interrupts to occur */
+ if (!wait_for_completion_timeout(&qup->xfer, HZ))
+ dev_err(qup->dev, "flush timed out\n");
+
+ qup_i2c_rel_dma(qup);
+ }
+ }
+
+ dma_unmap_sg(qup->dev, qup->btx.sg, tx_nents, DMA_TO_DEVICE);
+
+ if (rx_nents)
+ dma_unmap_sg(qup->dev, qup->brx.sg, rx_nents,
+ DMA_FROM_DEVICE);
+desc_err:
+ return ret;
+}
+
+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;
+
+ enable_irq(qup->irq);
+ ret = qup_i2c_req_dma(qup);
+
+ if (ret)
+ goto out;
+
+ qup->bus_err = 0;
+ qup->qup_err = 0;
+
+ writel(0, qup->base + QUP_MX_INPUT_CNT);
+ writel(0, qup->base + QUP_MX_OUTPUT_CNT);
+
+ /* set BAM mode */
+ writel(QUP_REPACK_EN | QUP_BAM_MODE, qup->base + QUP_IO_MODE);
+
+ /* mask fifo irqs */
+ writel((0x3 << 8), qup->base + QUP_OPERATIONAL_MASK);
+
+ /* set RUN STATE */
+ ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
+ if (ret)
+ goto out;
+
+ writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL);
+
+ qup->msg = msg;
+ ret = qup_i2c_bam_do_xfer(qup, qup->msg, num);
+out:
+ disable_irq(qup->irq);
+
+ qup->msg = NULL;
+ return ret;
+}
+
static int qup_i2c_wait_for_complete(struct qup_i2c_dev *qup,
struct i2c_msg *msg)
{
@@ -850,7 +1178,7 @@ static int qup_i2c_xfer_v2(struct i2c_adapter *adap,
int num)
{
struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
- int ret, idx;
+ int ret, len, idx = 0, use_dma = 0;
ret = pm_runtime_get_sync(qup->dev);
if (ret < 0)
@@ -865,7 +1193,27 @@ static int qup_i2c_xfer_v2(struct i2c_adapter *adap,
writel(I2C_MINI_CORE | I2C_N_VAL_V2, qup->base + QUP_CONFIG);
writel(QUP_V2_TAGS_EN, qup->base + QUP_I2C_MASTER_GEN);
- for (idx = 0; idx < num; idx++) {
+ if ((qup->is_dma)) {
+ /* All i2c_msgs should be transferred using either dma or cpu */
+ for (idx = 0; idx < num; idx++) {
+ if (msgs[idx].len == 0) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ len = (msgs[idx].len > qup->out_fifo_sz) ||
+ (msgs[idx].len > qup->in_fifo_sz);
+
+ if ((!is_vmalloc_addr(msgs[idx].buf)) && len) {
+ use_dma = 1;
+ } else {
+ use_dma = 0;
+ break;
+ }
+ }
+ }
+
+ do {
if (msgs[idx].len == 0) {
ret = -EINVAL;
goto out;
@@ -884,14 +1232,15 @@ static int qup_i2c_xfer_v2(struct i2c_adapter *adap,
reinit_completion(&qup->xfer);
- if (msgs[idx].flags & I2C_M_RD)
- ret = qup_i2c_read_one_v2(qup, &msgs[idx]);
- else
- ret = qup_i2c_write_one_v2(qup, &msgs[idx]);
-
- if (ret)
- break;
- }
+ if (use_dma) {
+ ret = qup_i2c_bam_xfer(adap, &msgs[idx], num);
+ } else {
+ if (msgs[idx].flags & I2C_M_RD)
+ ret = qup_i2c_read_one_v2(qup, &msgs[idx]);
+ else
+ ret = qup_i2c_write_one_v2(qup, &msgs[idx]);
+ }
+ } while ((idx++ < num) && !use_dma & !ret);
if (!ret)
ret = qup_i2c_change_state(qup, QUP_RESET_STATE);
@@ -958,6 +1307,7 @@ static int qup_i2c_probe(struct platform_device *pdev)
int ret, fs_div, hs_div;
int src_clk_freq;
u32 clk_freq = 100000;
+ int blocks;
qup = devm_kzalloc(&pdev->dev, sizeof(*qup), GFP_KERNEL);
if (!qup)
@@ -974,8 +1324,63 @@ static int qup_i2c_probe(struct platform_device *pdev)
qup->adap.quirks = &qup_i2c_quirks;
} else {
qup->adap.algo = &qup_i2c_algo_v2;
+ ret = qup_i2c_req_dma(qup);
+
+ if (ret == -EPROBE_DEFER)
+ goto fail_dma;
+ else if (ret != 0)
+ goto nodma;
+
+ blocks = (MX_BLOCKS << 1) + 1;
+ qup->btx.sg = devm_kzalloc(&pdev->dev,
+ sizeof(*qup->btx.sg) * blocks,
+ GFP_KERNEL);
+ if (!qup->btx.sg) {
+ ret = -ENOMEM;
+ goto fail_dma;
+ }
+ sg_init_table(qup->btx.sg, blocks);
+
+ qup->brx.sg = devm_kzalloc(&pdev->dev,
+ sizeof(*qup->brx.sg) * blocks,
+ GFP_KERNEL);
+ if (!qup->brx.sg) {
+ ret = -ENOMEM;
+ goto fail_dma;
+ }
+ sg_init_table(qup->brx.sg, blocks);
+
+ /* 2 tag bytes for each block + 5 for start, stop tags */
+ size = blocks * 2 + 5;
+ qup->dpool = dma_pool_create("qup_i2c-dma-pool", &pdev->dev,
+ size, 4, 0);
+
+ qup->start_tag.start = dma_pool_alloc(qup->dpool, GFP_KERNEL,
+ &qup->start_tag.addr);
+ if (!qup->start_tag.start) {
+ ret = -ENOMEM;
+ goto fail_dma;
+ }
+
+ qup->brx.tag.start = dma_pool_alloc(qup->dpool,
+ GFP_KERNEL,
+ &qup->brx.tag.addr);
+ if (!qup->brx.tag.start) {
+ ret = -ENOMEM;
+ goto fail_dma;
+ }
+
+ qup->btx.tag.start = dma_pool_alloc(qup->dpool,
+ GFP_KERNEL,
+ &qup->btx.tag.addr);
+ if (!qup->btx.tag.start) {
+ ret = -ENOMEM;
+ goto fail_dma;
+ }
+ qup->is_dma = 1;
}
+nodma:
/* We support frequencies up to FAST Mode (400KHz) */
if (!clk_freq || clk_freq > 400000) {
dev_err(qup->dev, "clock frequency not supported %d\n",
@@ -1093,6 +1498,11 @@ fail_runtime:
pm_runtime_set_suspended(qup->dev);
fail:
qup_i2c_disable_clocks(qup);
+fail_dma:
+ if (qup->btx.dma)
+ dma_release_channel(qup->btx.dma);
+ if (qup->brx.dma)
+ dma_release_channel(qup->brx.dma);
return ret;
}
@@ -1100,6 +1510,18 @@ static int qup_i2c_remove(struct platform_device *pdev)
{
struct qup_i2c_dev *qup = platform_get_drvdata(pdev);
+ if (qup->is_dma) {
+ dma_pool_free(qup->dpool, qup->start_tag.start,
+ qup->start_tag.addr);
+ dma_pool_free(qup->dpool, qup->brx.tag.start,
+ qup->brx.tag.addr);
+ dma_pool_free(qup->dpool, qup->btx.tag.start,
+ qup->btx.tag.addr);
+ dma_pool_destroy(qup->dpool);
+ dma_release_channel(qup->btx.dma);
+ dma_release_channel(qup->brx.dma);
+ }
+
disable_irq(qup->irq);
qup_i2c_disable_clocks(qup);
i2c_del_adapter(&qup->adap);