diff options
-rw-r--r-- | drivers/i2c/busses/i2c-qup.c | 473 |
1 files changed, 459 insertions, 14 deletions
diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c index f9009d6..30f3a2b 100644 --- a/drivers/i2c/busses/i2c-qup.c +++ b/drivers/i2c/busses/i2c-qup.c @@ -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 +545,306 @@ 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); +} + +static int 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) +{ + int ret; + + sg_set_buf(sg, buf, buflen); + ret = dma_map_sg(qup->dev, sg, 1, dir); + if (!ret) + return -EINVAL; + + if (!map) + sg_dma_address(sg) = tg->addr + ((u8 *)buf - tg->start); + + return 0; +} + +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, limit = QUP_READ_LIMIT; + 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 + limit) / limit; + rem = msg->len % 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 */ + ret = qup_sg_set_buf(&qup->brx.sg[rx_buf++], + &qup->brx.tag.start[0], + &qup->brx.tag, + 2, qup, 0, 0); + + if (ret) + return ret; + + ret = qup_sg_set_buf(&qup->brx.sg[rx_buf++], + &msg->buf[limit * i], + NULL, tlen, qup, + 1, DMA_FROM_DEVICE); + if (ret) + return ret; + + i++; + qup->blk.pos = i; + } + ret = qup_sg_set_buf(&qup->btx.sg[tx_buf++], + &qup->start_tag.start[off], + &qup->start_tag, len, qup, 0, 0); + if (ret) + return ret; + + off += len; + /* scratch buf to read the BAM EOT and FLUSH tags */ + ret = qup_sg_set_buf(&qup->brx.sg[rx_buf++], + &qup->brx.tag.start[0], + &qup->brx.tag, 2, + qup, 0, 0); + if (ret) + return ret; + } 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); + + ret = qup_sg_set_buf(&qup->btx.sg[tx_buf++], + tags, + &qup->start_tag, len, + qup, 0, 0); + if (ret) + return ret; + + tx_len += len; + ret = qup_sg_set_buf(&qup->btx.sg[tx_buf++], + &msg->buf[limit * i], + NULL, tlen, qup, 1, + DMA_TO_DEVICE); + if (ret) + return ret; + 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; + ret = qup_sg_set_buf(&qup->btx.sg[tx_buf++], + &qup->btx.tag.start[0], + &qup->btx.tag, len, + qup, 0, 0); + if (ret) + return ret; + 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 +1201,7 @@ 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 +1216,27 @@ 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 +1255,15 @@ 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 - 1)) && !use_dma && !ret); if (!ret) ret = qup_i2c_change_state(qup, QUP_RESET_STATE); @@ -958,6 +1330,7 @@ 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 +1347,63 @@ 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 = true; } +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", @@ -1073,7 +1501,7 @@ static int qup_i2c_probe(struct platform_device *pdev) i2c_set_adapdata(&qup->adap, qup); qup->adap.dev.parent = qup->dev; qup->adap.dev.of_node = pdev->dev.of_node; - qup->is_last = 1; + qup->is_last = true; strlcpy(qup->adap.name, "QUP I2C adapter", sizeof(qup->adap.name)); @@ -1093,6 +1521,11 @@ 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 +1533,18 @@ 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); |