diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/i2c/busses/i2c-qup.c | 2000 |
1 files changed, 2000 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c new file mode 100644 index 000000000..78682388e --- /dev/null +++ b/drivers/i2c/busses/i2c-qup.c @@ -0,0 +1,2000 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2009-2013, 2016-2018, The Linux Foundation. All rights reserved. + * Copyright (c) 2014, Sony Mobile Communications AB. + * + */ + +#include <linux/acpi.h> +#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> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/scatterlist.h> + +/* QUP Registers */ +#define QUP_CONFIG 0x000 +#define QUP_STATE 0x004 +#define QUP_IO_MODE 0x008 +#define QUP_SW_RESET 0x00c +#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 +#define QUP_MX_WRITE_CNT 0x150 +#define QUP_MX_INPUT_CNT 0x200 +#define QUP_MX_READ_CNT 0x208 +#define QUP_IN_FIFO_BASE 0x218 +#define QUP_I2C_CLK_CTL 0x400 +#define QUP_I2C_STATUS 0x404 +#define QUP_I2C_MASTER_GEN 0x408 + +/* QUP States and reset values */ +#define QUP_RESET_STATE 0 +#define QUP_RUN_STATE 1 +#define QUP_PAUSE_STATE 3 +#define QUP_STATE_MASK 3 + +#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 + +/* QUP OPERATIONAL FLAGS */ +#define QUP_I2C_NACK_FLAG BIT(3) +#define QUP_OUT_NOT_EMPTY BIT(4) +#define QUP_IN_NOT_EMPTY BIT(5) +#define QUP_OUT_FULL BIT(6) +#define QUP_OUT_SVC_FLAG BIT(8) +#define QUP_IN_SVC_FLAG BIT(9) +#define QUP_MX_OUTPUT_DONE BIT(10) +#define QUP_MX_INPUT_DONE BIT(11) +#define OUT_BLOCK_WRITE_REQ BIT(12) +#define IN_BLOCK_READ_REQ BIT(13) + +/* I2C mini core related values */ +#define QUP_NO_INPUT BIT(7) +#define QUP_CLOCK_AUTO_GATE BIT(13) +#define I2C_MINI_CORE (2 << 8) +#define I2C_N_VAL 15 +#define I2C_N_VAL_V2 7 + +/* Most significant word offset in FIFO port */ +#define QUP_MSW_SHIFT (I2C_N_VAL + 1) + +/* 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) + +#define QUP_REPACK_EN (QUP_UNPACK_EN | QUP_PACK_EN) +#define QUP_V2_TAGS_EN 1 + +#define QUP_OUTPUT_BLOCK_SIZE(x)(((x) >> 0) & 0x03) +#define QUP_OUTPUT_FIFO_SIZE(x) (((x) >> 2) & 0x07) +#define QUP_INPUT_BLOCK_SIZE(x) (((x) >> 5) & 0x03) +#define QUP_INPUT_FIFO_SIZE(x) (((x) >> 7) & 0x07) + +/* QUP tags */ +#define QUP_TAG_START (1 << 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 +#define QUP_TAG_V2_DATAWR 0x82 +#define QUP_TAG_V2_DATAWR_STOP 0x83 +#define QUP_TAG_V2_DATARD 0x85 +#define QUP_TAG_V2_DATARD_NACK 0x86 +#define QUP_TAG_V2_DATARD_STOP 0x87 + +/* Status, Error flags */ +#define I2C_STATUS_WR_BUFFER_FULL BIT(0) +#define I2C_STATUS_BUS_ACTIVE BIT(8) +#define I2C_STATUS_ERROR_MASK 0x38000fc +#define QUP_STATUS_ERROR_FLAGS 0x7c + +#define QUP_READ_LIMIT 256 +#define SET_BIT 0x1 +#define RESET_BIT 0x0 +#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 + * the top of maximum transfer time calculated from i2c bus speed to compensate + * the overheads. + */ +#define TOUT_MIN 2 + +/* Default values. Use these if FW query fails */ +#define DEFAULT_CLK_FREQ I2C_MAX_STANDARD_MODE_FREQ +#define DEFAULT_SRC_CLK 20000000 + +/* + * Max tags length (start, stop and maximum 2 bytes address) for each QUP + * data transfer + */ +#define QUP_MAX_TAGS_LEN 4 +/* Max data length for each DATARD tags */ +#define RECV_MAX_DATA_LEN 254 +/* TAG length for DATA READ in RX FIFO */ +#define READ_RX_TAGS_LEN 2 + +static unsigned int scl_freq; +module_param_named(scl_freq, scl_freq, uint, 0444); +MODULE_PARM_DESC(scl_freq, "SCL frequency override"); + +/* + * count: no of blocks + * pos: current block number + * tx_tag_len: tx tag length for current block + * rx_tag_len: rx tag length for current block + * data_len: remaining data length for current message + * cur_blk_len: data length for current block + * total_tx_len: total tx length including tag bytes for current QUP transfer + * total_rx_len: total rx length including tag bytes for current QUP transfer + * tx_fifo_data_pos: current byte number in TX FIFO word + * tx_fifo_free: number of free bytes in current QUP block write. + * rx_fifo_data_pos: current byte number in RX FIFO word + * fifo_available: number of available bytes in RX FIFO for current + * QUP block read + * tx_fifo_data: QUP TX FIFO write works on word basis (4 bytes). New byte write + * to TX FIFO will be appended in this data and will be written to + * TX FIFO when all the 4 bytes are available. + * rx_fifo_data: QUP RX FIFO read works on word basis (4 bytes). This will + * contains the 4 bytes of RX data. + * cur_data: pointer to tell cur data position for current message + * cur_tx_tags: pointer to tell cur position in tags + * tx_tags_sent: all tx tag bytes have been written in FIFO word + * send_last_word: for tx FIFO, last word send is pending in current block + * rx_bytes_read: if all the bytes have been read from rx FIFO. + * rx_tags_fetched: all the rx tag bytes have been fetched from rx fifo word + * is_tx_blk_mode: whether tx uses block or FIFO mode in case of non BAM xfer. + * is_rx_blk_mode: whether rx uses block or FIFO mode in case of non BAM xfer. + * tags: contains tx tag bytes for current QUP transfer + */ +struct qup_i2c_block { + int count; + int pos; + int tx_tag_len; + int rx_tag_len; + int data_len; + int cur_blk_len; + int total_tx_len; + int total_rx_len; + int tx_fifo_data_pos; + int tx_fifo_free; + int rx_fifo_data_pos; + int fifo_available; + u32 tx_fifo_data; + u32 rx_fifo_data; + u8 *cur_data; + u8 *cur_tx_tags; + bool tx_tags_sent; + bool send_last_word; + bool rx_tags_fetched; + bool rx_bytes_read; + bool is_tx_blk_mode; + bool is_rx_blk_mode; + 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; + unsigned int sg_cnt; +}; + +struct qup_i2c_dev { + struct device *dev; + void __iomem *base; + int irq; + struct clk *clk; + struct clk *pclk; + struct i2c_adapter adap; + + int clk_ctl; + int out_fifo_sz; + int in_fifo_sz; + int out_blk_sz; + int in_blk_sz; + + int blk_xfer_limit; + unsigned long one_byte_t; + unsigned long xfer_timeout; + struct qup_i2c_block blk; + + struct i2c_msg *msg; + /* Current posion in user message buffer */ + int pos; + /* I2C protocol errors */ + u32 bus_err; + /* QUP core errors */ + u32 qup_err; + + /* To check if this is the last msg */ + bool is_last; + bool is_smbus_read; + + /* To configure when bus is in run state */ + u32 config_run; + + /* dma parameters */ + 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; + /* The threshold length above which block mode will be used */ + unsigned int blk_mode_threshold; + struct dma_pool *dpool; + struct qup_i2c_tag start_tag; + struct qup_i2c_bam brx; + struct qup_i2c_bam btx; + + struct completion xfer; + /* function to write data in tx fifo */ + void (*write_tx_fifo)(struct qup_i2c_dev *qup); + /* function to read data from rx fifo */ + void (*read_rx_fifo)(struct qup_i2c_dev *qup); + /* function to write tags in tx fifo for i2c read transfer */ + void (*write_rx_tags)(struct qup_i2c_dev *qup); +}; + +static irqreturn_t qup_i2c_interrupt(int irq, void *dev) +{ + struct qup_i2c_dev *qup = dev; + struct qup_i2c_block *blk = &qup->blk; + u32 bus_err; + u32 qup_err; + u32 opflags; + + bus_err = readl(qup->base + QUP_I2C_STATUS); + qup_err = readl(qup->base + QUP_ERROR_FLAGS); + opflags = readl(qup->base + QUP_OPERATIONAL); + + if (!qup->msg) { + /* Clear Error interrupt */ + writel(QUP_RESET_STATE, qup->base + QUP_STATE); + return IRQ_HANDLED; + } + + bus_err &= I2C_STATUS_ERROR_MASK; + qup_err &= QUP_STATUS_ERROR_FLAGS; + + /* Clear the error bits in QUP_ERROR_FLAGS */ + if (qup_err) + writel(qup_err, qup->base + QUP_ERROR_FLAGS); + + /* Clear the error bits in QUP_I2C_STATUS */ + if (bus_err) + writel(bus_err, qup->base + QUP_I2C_STATUS); + + /* + * Check for BAM mode and returns if already error has come for current + * transfer. In Error case, sometimes, QUP generates more than one + * interrupt. + */ + if (qup->use_dma && (qup->qup_err || qup->bus_err)) + return IRQ_HANDLED; + + /* Reset the QUP State in case of error */ + if (qup_err || bus_err) { + /* + * Don’t reset the QUP state in case of BAM mode. The BAM + * flush operation needs to be scheduled in transfer function + * which will clear the remaining schedule descriptors in BAM + * HW FIFO and generates the BAM interrupt. + */ + if (!qup->use_dma) + writel(QUP_RESET_STATE, qup->base + QUP_STATE); + goto done; + } + + if (opflags & QUP_OUT_SVC_FLAG) { + writel(QUP_OUT_SVC_FLAG, qup->base + QUP_OPERATIONAL); + + if (opflags & OUT_BLOCK_WRITE_REQ) { + blk->tx_fifo_free += qup->out_blk_sz; + if (qup->msg->flags & I2C_M_RD) + qup->write_rx_tags(qup); + else + qup->write_tx_fifo(qup); + } + } + + if (opflags & QUP_IN_SVC_FLAG) { + writel(QUP_IN_SVC_FLAG, qup->base + QUP_OPERATIONAL); + + if (!blk->is_rx_blk_mode) { + blk->fifo_available += qup->in_fifo_sz; + qup->read_rx_fifo(qup); + } else if (opflags & IN_BLOCK_READ_REQ) { + blk->fifo_available += qup->in_blk_sz; + qup->read_rx_fifo(qup); + } + } + + if (qup->msg->flags & I2C_M_RD) { + if (!blk->rx_bytes_read) + return IRQ_HANDLED; + } else { + /* + * Ideally, QUP_MAX_OUTPUT_DONE_FLAG should be checked + * for FIFO mode also. But, QUP_MAX_OUTPUT_DONE_FLAG lags + * behind QUP_OUTPUT_SERVICE_FLAG sometimes. The only reason + * of interrupt for write message in FIFO mode is + * QUP_MAX_OUTPUT_DONE_FLAG condition. + */ + if (blk->is_tx_blk_mode && !(opflags & QUP_MX_OUTPUT_DONE)) + return IRQ_HANDLED; + } + +done: + qup->qup_err = qup_err; + qup->bus_err = bus_err; + complete(&qup->xfer); + return IRQ_HANDLED; +} + +static int qup_i2c_poll_state_mask(struct qup_i2c_dev *qup, + u32 req_state, u32 req_mask) +{ + int retries = 1; + u32 state; + + /* + * State transition takes 3 AHB clocks cycles + 3 I2C master clock + * cycles. So retry once after a 1uS delay. + */ + do { + state = readl(qup->base + QUP_STATE); + + if (state & QUP_STATE_VALID && + (state & req_mask) == req_state) + return 0; + + udelay(1); + } while (retries--); + + return -ETIMEDOUT; +} + +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); +} + +static int qup_i2c_poll_state_i2c_master(struct qup_i2c_dev *qup) +{ + return qup_i2c_poll_state_mask(qup, QUP_I2C_MAST_GEN, QUP_I2C_MAST_GEN); +} + +static int qup_i2c_change_state(struct qup_i2c_dev *qup, u32 state) +{ + if (qup_i2c_poll_state_valid(qup) != 0) + return -EIO; + + writel(state, qup->base + QUP_STATE); + + if (qup_i2c_poll_state(qup, state) != 0) + return -EIO; + return 0; +} + +/* Check if I2C bus returns to IDLE state */ +static int qup_i2c_bus_active(struct qup_i2c_dev *qup, int len) +{ + unsigned long timeout; + u32 status; + int ret = 0; + + timeout = jiffies + len * 4; + for (;;) { + status = readl(qup->base + QUP_I2C_STATUS); + if (!(status & I2C_STATUS_BUS_ACTIVE)) + break; + + if (time_after(jiffies, timeout)) + ret = -ETIMEDOUT; + + usleep_range(len, len * 2); + } + + return ret; +} + +static void qup_i2c_write_tx_fifo_v1(struct qup_i2c_dev *qup) +{ + struct qup_i2c_block *blk = &qup->blk; + struct i2c_msg *msg = qup->msg; + u32 addr = i2c_8bit_addr_from_msg(msg); + u32 qup_tag; + int idx; + u32 val; + + if (qup->pos == 0) { + val = QUP_TAG_START | addr; + idx = 1; + blk->tx_fifo_free--; + } else { + val = 0; + idx = 0; + } + + while (blk->tx_fifo_free && qup->pos < msg->len) { + if (qup->pos == msg->len - 1) + qup_tag = QUP_TAG_STOP; + else + qup_tag = QUP_TAG_DATA; + + if (idx & 1) + val |= (qup_tag | msg->buf[qup->pos]) << QUP_MSW_SHIFT; + else + val = qup_tag | msg->buf[qup->pos]; + + /* Write out the pair and the last odd value */ + if (idx & 1 || qup->pos == msg->len - 1) + writel(val, qup->base + QUP_OUT_FIFO_BASE); + + qup->pos++; + idx++; + blk->tx_fifo_free--; + } +} + +static void qup_i2c_set_blk_data(struct qup_i2c_dev *qup, + struct i2c_msg *msg) +{ + qup->blk.pos = 0; + qup->blk.data_len = msg->len; + qup->blk.count = DIV_ROUND_UP(msg->len, qup->blk_xfer_limit); +} + +static int qup_i2c_get_data_len(struct qup_i2c_dev *qup) +{ + int data_len; + + if (qup->blk.data_len > qup->blk_xfer_limit) + data_len = qup->blk_xfer_limit; + else + data_len = qup->blk.data_len; + + return data_len; +} + +static bool qup_i2c_check_msg_len(struct i2c_msg *msg) +{ + return ((msg->flags & I2C_M_RD) && (msg->flags & I2C_M_RECV_LEN)); +} + +static int qup_i2c_set_tags_smb(u16 addr, u8 *tags, struct qup_i2c_dev *qup, + struct i2c_msg *msg) +{ + int len = 0; + + if (qup->is_smbus_read) { + tags[len++] = QUP_TAG_V2_DATARD_STOP; + tags[len++] = qup_i2c_get_data_len(qup); + } else { + tags[len++] = QUP_TAG_V2_START; + tags[len++] = addr & 0xff; + + if (msg->flags & I2C_M_TEN) + tags[len++] = addr >> 8; + + tags[len++] = QUP_TAG_V2_DATARD; + /* Read 1 byte indicating the length of the SMBus message */ + tags[len++] = 1; + } + return len; +} + +static int qup_i2c_set_tags(u8 *tags, struct qup_i2c_dev *qup, + struct i2c_msg *msg) +{ + u16 addr = i2c_8bit_addr_from_msg(msg); + int len = 0; + int data_len; + + int last = (qup->blk.pos == (qup->blk.count - 1)) && (qup->is_last); + + /* Handle tags for SMBus block read */ + if (qup_i2c_check_msg_len(msg)) + return qup_i2c_set_tags_smb(addr, tags, qup, msg); + + if (qup->blk.pos == 0) { + tags[len++] = QUP_TAG_V2_START; + tags[len++] = addr & 0xff; + + if (msg->flags & I2C_M_TEN) + tags[len++] = addr >> 8; + } + + /* Send _STOP commands for the last block */ + if (last) { + if (msg->flags & I2C_M_RD) + tags[len++] = QUP_TAG_V2_DATARD_STOP; + else + tags[len++] = QUP_TAG_V2_DATAWR_STOP; + } else { + if (msg->flags & I2C_M_RD) + tags[len++] = qup->blk.pos == (qup->blk.count - 1) ? + QUP_TAG_V2_DATARD_NACK : + QUP_TAG_V2_DATARD; + else + tags[len++] = QUP_TAG_V2_DATAWR; + } + + data_len = qup_i2c_get_data_len(qup); + + /* 0 implies 256 bytes */ + if (data_len == QUP_READ_LIMIT) + tags[len++] = 0; + else + tags[len++] = data_len; + + return len; +} + + +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, + unsigned int buflen, struct qup_i2c_dev *qup, + int dir) +{ + int ret; + + sg_set_buf(sg, buf, buflen); + ret = dma_map_sg(qup->dev, sg, 1, dir); + if (!ret) + return -EINVAL; + + 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_chan(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_chan(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_make_desc(struct qup_i2c_dev *qup, struct i2c_msg *msg) +{ + int ret = 0, limit = QUP_READ_LIMIT; + u32 len = 0, blocks, rem; + u32 i = 0, tlen, tx_len = 0; + u8 *tags; + + qup->blk_xfer_limit = QUP_READ_LIMIT; + qup_i2c_set_blk_data(qup, msg); + + 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; + + /* 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); + + 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; + + 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; + + 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; + + 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; + } + + 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) { + qup->btx.tag.start[0] = QUP_BAM_INPUT_EOT; + len++; + + /* scratch buf to read the BAM EOT FLUSH tags */ + ret = qup_sg_set_buf(&qup->brx.sg[rx_cnt++], + &qup->brx.tag.start[0], + 1, qup, DMA_FROM_DEVICE); + if (ret) + return ret; + } + + 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; + + txd = dmaengine_prep_slave_sg(qup->btx.dma, qup->btx.sg, tx_cnt, + 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_cnt) { + 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_cnt) { + rxd = dmaengine_prep_slave_sg(qup->brx.dma, qup->brx.sg, + rx_cnt, 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_sync(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, qup->xfer_timeout)) { + dev_err(qup->dev, "normal trans timed out\n"); + ret = -ETIMEDOUT; + } + + if (ret || qup->bus_err || qup->qup_err) { + reinit_completion(&qup->xfer); + + ret = qup_i2c_change_state(qup, QUP_RUN_STATE); + if (ret) { + dev_err(qup->dev, "change to run state timed out"); + goto desc_err; + } + + 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"); + + ret = (qup->bus_err & QUP_I2C_NACK_FLAG) ? -ENXIO : -EIO; + } + +desc_err: + dma_unmap_sg(qup->dev, qup->btx.sg, tx_cnt, DMA_TO_DEVICE); + + if (rx_cnt) + dma_unmap_sg(qup->dev, qup->brx.sg, rx_cnt, + DMA_FROM_DEVICE); + + 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); + + if (ret) + goto out; + + 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_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); + } + } + +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) +{ + unsigned long left; + int ret = 0; + + left = wait_for_completion_timeout(&qup->xfer, qup->xfer_timeout); + if (!left) { + writel(1, qup->base + QUP_SW_RESET); + ret = -ETIMEDOUT; + } + + if (qup->bus_err || qup->qup_err) + ret = (qup->bus_err & QUP_I2C_NACK_FLAG) ? -ENXIO : -EIO; + + return ret; +} + +static void qup_i2c_read_rx_fifo_v1(struct qup_i2c_dev *qup) +{ + struct qup_i2c_block *blk = &qup->blk; + struct i2c_msg *msg = qup->msg; + u32 val = 0; + int idx = 0; + + while (blk->fifo_available && qup->pos < msg->len) { + if ((idx & 1) == 0) { + /* Reading 2 words at time */ + val = readl(qup->base + QUP_IN_FIFO_BASE); + msg->buf[qup->pos++] = val & 0xFF; + } else { + msg->buf[qup->pos++] = val >> QUP_MSW_SHIFT; + } + idx++; + blk->fifo_available--; + } + + if (qup->pos == msg->len) + blk->rx_bytes_read = true; +} + +static void qup_i2c_write_rx_tags_v1(struct qup_i2c_dev *qup) +{ + struct i2c_msg *msg = qup->msg; + u32 addr, len, val; + + addr = i2c_8bit_addr_from_msg(msg); + + /* 0 is used to specify a length 256 (QUP_READ_LIMIT) */ + len = (msg->len == QUP_READ_LIMIT) ? 0 : msg->len; + + val = ((QUP_TAG_REC | len) << QUP_MSW_SHIFT) | QUP_TAG_START | addr; + writel(val, qup->base + QUP_OUT_FIFO_BASE); +} + +static void qup_i2c_conf_v1(struct qup_i2c_dev *qup) +{ + struct qup_i2c_block *blk = &qup->blk; + u32 qup_config = I2C_MINI_CORE | I2C_N_VAL; + u32 io_mode = QUP_REPACK_EN; + + blk->is_tx_blk_mode = blk->total_tx_len > qup->out_fifo_sz; + blk->is_rx_blk_mode = blk->total_rx_len > qup->in_fifo_sz; + + if (blk->is_tx_blk_mode) { + io_mode |= QUP_OUTPUT_BLK_MODE; + writel(0, qup->base + QUP_MX_WRITE_CNT); + writel(blk->total_tx_len, qup->base + QUP_MX_OUTPUT_CNT); + } else { + writel(0, qup->base + QUP_MX_OUTPUT_CNT); + writel(blk->total_tx_len, qup->base + QUP_MX_WRITE_CNT); + } + + if (blk->total_rx_len) { + if (blk->is_rx_blk_mode) { + io_mode |= QUP_INPUT_BLK_MODE; + writel(0, qup->base + QUP_MX_READ_CNT); + writel(blk->total_rx_len, qup->base + QUP_MX_INPUT_CNT); + } else { + writel(0, qup->base + QUP_MX_INPUT_CNT); + writel(blk->total_rx_len, qup->base + QUP_MX_READ_CNT); + } + } else { + qup_config |= QUP_NO_INPUT; + } + + writel(qup_config, qup->base + QUP_CONFIG); + writel(io_mode, qup->base + QUP_IO_MODE); +} + +static void qup_i2c_clear_blk_v1(struct qup_i2c_block *blk) +{ + blk->tx_fifo_free = 0; + blk->fifo_available = 0; + blk->rx_bytes_read = false; +} + +static int qup_i2c_conf_xfer_v1(struct qup_i2c_dev *qup, bool is_rx) +{ + struct qup_i2c_block *blk = &qup->blk; + int ret; + + qup_i2c_clear_blk_v1(blk); + qup_i2c_conf_v1(qup); + ret = qup_i2c_change_state(qup, QUP_RUN_STATE); + if (ret) + return ret; + + writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL); + + ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE); + if (ret) + return ret; + + reinit_completion(&qup->xfer); + enable_irq(qup->irq); + if (!blk->is_tx_blk_mode) { + blk->tx_fifo_free = qup->out_fifo_sz; + + if (is_rx) + qup_i2c_write_rx_tags_v1(qup); + else + qup_i2c_write_tx_fifo_v1(qup); + } + + ret = qup_i2c_change_state(qup, QUP_RUN_STATE); + if (ret) + goto err; + + ret = qup_i2c_wait_for_complete(qup, qup->msg); + if (ret) + goto err; + + ret = qup_i2c_bus_active(qup, ONE_BYTE); + +err: + disable_irq(qup->irq); + return ret; +} + +static int qup_i2c_write_one(struct qup_i2c_dev *qup) +{ + struct i2c_msg *msg = qup->msg; + struct qup_i2c_block *blk = &qup->blk; + + qup->pos = 0; + blk->total_tx_len = msg->len + 1; + blk->total_rx_len = 0; + + return qup_i2c_conf_xfer_v1(qup, false); +} + +static int qup_i2c_read_one(struct qup_i2c_dev *qup) +{ + struct qup_i2c_block *blk = &qup->blk; + + qup->pos = 0; + blk->total_tx_len = 2; + blk->total_rx_len = qup->msg->len; + + return qup_i2c_conf_xfer_v1(qup, true); +} + +static int qup_i2c_xfer(struct i2c_adapter *adap, + struct i2c_msg msgs[], + int num) +{ + struct qup_i2c_dev *qup = i2c_get_adapdata(adap); + int ret, idx; + + ret = pm_runtime_get_sync(qup->dev); + if (ret < 0) + goto out; + + qup->bus_err = 0; + qup->qup_err = 0; + + writel(1, qup->base + QUP_SW_RESET); + ret = qup_i2c_poll_state(qup, QUP_RESET_STATE); + if (ret) + goto out; + + /* Configure QUP as I2C mini core */ + writel(I2C_MINI_CORE | I2C_N_VAL, qup->base + QUP_CONFIG); + + for (idx = 0; idx < num; idx++) { + if (qup_i2c_poll_state_i2c_master(qup)) { + ret = -EIO; + goto out; + } + + if (qup_i2c_check_msg_len(&msgs[idx])) { + ret = -EINVAL; + goto out; + } + + qup->msg = &msgs[idx]; + if (msgs[idx].flags & I2C_M_RD) + ret = qup_i2c_read_one(qup); + else + ret = qup_i2c_write_one(qup); + + if (ret) + break; + + ret = qup_i2c_change_state(qup, QUP_RESET_STATE); + if (ret) + break; + } + + if (ret == 0) + ret = num; +out: + + pm_runtime_mark_last_busy(qup->dev); + pm_runtime_put_autosuspend(qup->dev); + + return ret; +} + +/* + * Configure registers related with reconfiguration during run and call it + * before each i2c sub transfer. + */ +static void qup_i2c_conf_count_v2(struct qup_i2c_dev *qup) +{ + struct qup_i2c_block *blk = &qup->blk; + u32 qup_config = I2C_MINI_CORE | I2C_N_VAL_V2; + + if (blk->is_tx_blk_mode) + writel(qup->config_run | blk->total_tx_len, + qup->base + QUP_MX_OUTPUT_CNT); + else + writel(qup->config_run | blk->total_tx_len, + qup->base + QUP_MX_WRITE_CNT); + + if (blk->total_rx_len) { + if (blk->is_rx_blk_mode) + writel(qup->config_run | blk->total_rx_len, + qup->base + QUP_MX_INPUT_CNT); + else + writel(qup->config_run | blk->total_rx_len, + qup->base + QUP_MX_READ_CNT); + } else { + qup_config |= QUP_NO_INPUT; + } + + writel(qup_config, qup->base + QUP_CONFIG); +} + +/* + * Configure registers related with transfer mode (FIFO/Block) + * before starting of i2c transfer. It will be called only once in + * QUP RESET state. + */ +static void qup_i2c_conf_mode_v2(struct qup_i2c_dev *qup) +{ + struct qup_i2c_block *blk = &qup->blk; + u32 io_mode = QUP_REPACK_EN; + + if (blk->is_tx_blk_mode) { + io_mode |= QUP_OUTPUT_BLK_MODE; + writel(0, qup->base + QUP_MX_WRITE_CNT); + } else { + writel(0, qup->base + QUP_MX_OUTPUT_CNT); + } + + if (blk->is_rx_blk_mode) { + io_mode |= QUP_INPUT_BLK_MODE; + writel(0, qup->base + QUP_MX_READ_CNT); + } else { + writel(0, qup->base + QUP_MX_INPUT_CNT); + } + + writel(io_mode, qup->base + QUP_IO_MODE); +} + +/* Clear required variables before starting of any QUP v2 sub transfer. */ +static void qup_i2c_clear_blk_v2(struct qup_i2c_block *blk) +{ + blk->send_last_word = false; + blk->tx_tags_sent = false; + blk->tx_fifo_data = 0; + blk->tx_fifo_data_pos = 0; + blk->tx_fifo_free = 0; + + blk->rx_tags_fetched = false; + blk->rx_bytes_read = false; + blk->rx_fifo_data = 0; + blk->rx_fifo_data_pos = 0; + blk->fifo_available = 0; +} + +/* Receive data from RX FIFO for read message in QUP v2 i2c transfer. */ +static void qup_i2c_recv_data(struct qup_i2c_dev *qup) +{ + struct qup_i2c_block *blk = &qup->blk; + int j; + + for (j = blk->rx_fifo_data_pos; + blk->cur_blk_len && blk->fifo_available; + blk->cur_blk_len--, blk->fifo_available--) { + if (j == 0) + blk->rx_fifo_data = readl(qup->base + QUP_IN_FIFO_BASE); + + *(blk->cur_data++) = blk->rx_fifo_data; + blk->rx_fifo_data >>= 8; + + if (j == 3) + j = 0; + else + j++; + } + + blk->rx_fifo_data_pos = j; +} + +/* Receive tags for read message in QUP v2 i2c transfer. */ +static void qup_i2c_recv_tags(struct qup_i2c_dev *qup) +{ + struct qup_i2c_block *blk = &qup->blk; + + blk->rx_fifo_data = readl(qup->base + QUP_IN_FIFO_BASE); + blk->rx_fifo_data >>= blk->rx_tag_len * 8; + blk->rx_fifo_data_pos = blk->rx_tag_len; + blk->fifo_available -= blk->rx_tag_len; +} + +/* + * Read the data and tags from RX FIFO. Since in read case, the tags will be + * preceded by received data bytes so + * 1. Check if rx_tags_fetched is false i.e. the start of QUP block so receive + * all tag bytes and discard that. + * 2. Read the data from RX FIFO. When all the data bytes have been read then + * set rx_bytes_read to true. + */ +static void qup_i2c_read_rx_fifo_v2(struct qup_i2c_dev *qup) +{ + struct qup_i2c_block *blk = &qup->blk; + + if (!blk->rx_tags_fetched) { + qup_i2c_recv_tags(qup); + blk->rx_tags_fetched = true; + } + + qup_i2c_recv_data(qup); + if (!blk->cur_blk_len) + blk->rx_bytes_read = true; +} + +/* + * Write bytes in TX FIFO for write message in QUP v2 i2c transfer. QUP TX FIFO + * write works on word basis (4 bytes). Append new data byte write for TX FIFO + * in tx_fifo_data and write to TX FIFO when all the 4 bytes are present. + */ +static void +qup_i2c_write_blk_data(struct qup_i2c_dev *qup, u8 **data, unsigned int *len) +{ + struct qup_i2c_block *blk = &qup->blk; + unsigned int j; + + for (j = blk->tx_fifo_data_pos; *len && blk->tx_fifo_free; + (*len)--, blk->tx_fifo_free--) { + blk->tx_fifo_data |= *(*data)++ << (j * 8); + if (j == 3) { + writel(blk->tx_fifo_data, + qup->base + QUP_OUT_FIFO_BASE); + blk->tx_fifo_data = 0x0; + j = 0; + } else { + j++; + } + } + + blk->tx_fifo_data_pos = j; +} + +/* Transfer tags for read message in QUP v2 i2c transfer. */ +static void qup_i2c_write_rx_tags_v2(struct qup_i2c_dev *qup) +{ + struct qup_i2c_block *blk = &qup->blk; + + qup_i2c_write_blk_data(qup, &blk->cur_tx_tags, &blk->tx_tag_len); + if (blk->tx_fifo_data_pos) + writel(blk->tx_fifo_data, qup->base + QUP_OUT_FIFO_BASE); +} + +/* + * Write the data and tags in TX FIFO. Since in write case, both tags and data + * need to be written and QUP write tags can have maximum 256 data length, so + * + * 1. Check if tx_tags_sent is false i.e. the start of QUP block so write the + * tags to TX FIFO and set tx_tags_sent to true. + * 2. Check if send_last_word is true. It will be set when last few data bytes + * (less than 4 bytes) are remaining to be written in FIFO because of no FIFO + * space. All this data bytes are available in tx_fifo_data so write this + * in FIFO. + * 3. Write the data to TX FIFO and check for cur_blk_len. If it is non zero + * then more data is pending otherwise following 3 cases can be possible + * a. if tx_fifo_data_pos is zero i.e. all the data bytes in this block + * have been written in TX FIFO so nothing else is required. + * b. tx_fifo_free is non zero i.e tx FIFO is free so copy the remaining data + * from tx_fifo_data to tx FIFO. Since, qup_i2c_write_blk_data do write + * in 4 bytes and FIFO space is in multiple of 4 bytes so tx_fifo_free + * will be always greater than or equal to 4 bytes. + * c. tx_fifo_free is zero. In this case, last few bytes (less than 4 + * bytes) are copied to tx_fifo_data but couldn't be sent because of + * FIFO full so make send_last_word true. + */ +static void qup_i2c_write_tx_fifo_v2(struct qup_i2c_dev *qup) +{ + struct qup_i2c_block *blk = &qup->blk; + + if (!blk->tx_tags_sent) { + qup_i2c_write_blk_data(qup, &blk->cur_tx_tags, + &blk->tx_tag_len); + blk->tx_tags_sent = true; + } + + if (blk->send_last_word) + goto send_last_word; + + qup_i2c_write_blk_data(qup, &blk->cur_data, &blk->cur_blk_len); + if (!blk->cur_blk_len) { + if (!blk->tx_fifo_data_pos) + return; + + if (blk->tx_fifo_free) + goto send_last_word; + + blk->send_last_word = true; + } + + return; + +send_last_word: + writel(blk->tx_fifo_data, qup->base + QUP_OUT_FIFO_BASE); +} + +/* + * Main transfer function which read or write i2c data. + * The QUP v2 supports reconfiguration during run in which multiple i2c sub + * transfers can be scheduled. + */ +static int +qup_i2c_conf_xfer_v2(struct qup_i2c_dev *qup, bool is_rx, bool is_first, + bool change_pause_state) +{ + struct qup_i2c_block *blk = &qup->blk; + struct i2c_msg *msg = qup->msg; + int ret; + + /* + * Check if its SMBus Block read for which the top level read will be + * done into 2 QUP reads. One with message length 1 while other one is + * with actual length. + */ + if (qup_i2c_check_msg_len(msg)) { + if (qup->is_smbus_read) { + /* + * If the message length is already read in + * the first byte of the buffer, account for + * that by setting the offset + */ + blk->cur_data += 1; + is_first = false; + } else { + change_pause_state = false; + } + } + + qup->config_run = is_first ? 0 : QUP_I2C_MX_CONFIG_DURING_RUN; + + qup_i2c_clear_blk_v2(blk); + qup_i2c_conf_count_v2(qup); + + /* If it is first sub transfer, then configure i2c bus clocks */ + if (is_first) { + ret = qup_i2c_change_state(qup, QUP_RUN_STATE); + if (ret) + return ret; + + writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL); + + ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE); + if (ret) + return ret; + } + + reinit_completion(&qup->xfer); + enable_irq(qup->irq); + /* + * In FIFO mode, tx FIFO can be written directly while in block mode the + * it will be written after getting OUT_BLOCK_WRITE_REQ interrupt + */ + if (!blk->is_tx_blk_mode) { + blk->tx_fifo_free = qup->out_fifo_sz; + + if (is_rx) + qup_i2c_write_rx_tags_v2(qup); + else + qup_i2c_write_tx_fifo_v2(qup); + } + + ret = qup_i2c_change_state(qup, QUP_RUN_STATE); + if (ret) + goto err; + + ret = qup_i2c_wait_for_complete(qup, msg); + if (ret) + goto err; + + /* Move to pause state for all the transfers, except last one */ + if (change_pause_state) { + ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE); + if (ret) + goto err; + } + +err: + disable_irq(qup->irq); + return ret; +} + +/* + * Transfer one read/write message in i2c transfer. It splits the message into + * multiple of blk_xfer_limit data length blocks and schedule each + * QUP block individually. + */ +static int qup_i2c_xfer_v2_msg(struct qup_i2c_dev *qup, int msg_id, bool is_rx) +{ + int ret = 0; + unsigned int data_len, i; + struct i2c_msg *msg = qup->msg; + struct qup_i2c_block *blk = &qup->blk; + u8 *msg_buf = msg->buf; + + qup->blk_xfer_limit = is_rx ? RECV_MAX_DATA_LEN : QUP_READ_LIMIT; + qup_i2c_set_blk_data(qup, msg); + + for (i = 0; i < blk->count; i++) { + data_len = qup_i2c_get_data_len(qup); + blk->pos = i; + blk->cur_tx_tags = blk->tags; + blk->cur_blk_len = data_len; + blk->tx_tag_len = + qup_i2c_set_tags(blk->cur_tx_tags, qup, qup->msg); + + blk->cur_data = msg_buf; + + if (is_rx) { + blk->total_tx_len = blk->tx_tag_len; + blk->rx_tag_len = 2; + blk->total_rx_len = blk->rx_tag_len + data_len; + } else { + blk->total_tx_len = blk->tx_tag_len + data_len; + blk->total_rx_len = 0; + } + + ret = qup_i2c_conf_xfer_v2(qup, is_rx, !msg_id && !i, + !qup->is_last || i < blk->count - 1); + if (ret) + return ret; + + /* Handle SMBus block read length */ + if (qup_i2c_check_msg_len(msg) && msg->len == 1 && + !qup->is_smbus_read) { + if (msg->buf[0] > I2C_SMBUS_BLOCK_MAX) + return -EPROTO; + + msg->len = msg->buf[0]; + qup->is_smbus_read = true; + ret = qup_i2c_xfer_v2_msg(qup, msg_id, true); + qup->is_smbus_read = false; + if (ret) + return ret; + + msg->len += 1; + } + + msg_buf += data_len; + blk->data_len -= qup->blk_xfer_limit; + } + + return ret; +} + +/* + * QUP v2 supports 3 modes + * Programmed IO using FIFO mode : Less than FIFO size + * Programmed IO using Block mode : Greater than FIFO size + * DMA using BAM : Appropriate for any transaction size but the address should + * be DMA applicable + * + * This function determines the mode which will be used for this transfer. An + * i2c transfer contains multiple message. Following are the rules to determine + * the mode used. + * 1. Determine complete length, maximum tx and rx length for complete transfer. + * 2. If complete transfer length is greater than fifo size then use the DMA + * mode. + * 3. In FIFO or block mode, tx and rx can operate in different mode so check + * for maximum tx and rx length to determine mode. + */ +static int +qup_i2c_determine_mode_v2(struct qup_i2c_dev *qup, + struct i2c_msg msgs[], int num) +{ + int idx; + bool no_dma = false; + unsigned int max_tx_len = 0, max_rx_len = 0, total_len = 0; + + /* All i2c_msgs should be transferred using either dma or cpu */ + for (idx = 0; idx < num; idx++) { + if (msgs[idx].flags & I2C_M_RD) + max_rx_len = max_t(unsigned int, max_rx_len, + msgs[idx].len); + else + max_tx_len = max_t(unsigned int, max_tx_len, + msgs[idx].len); + + if (is_vmalloc_addr(msgs[idx].buf)) + no_dma = true; + + total_len += msgs[idx].len; + } + + if (!no_dma && qup->is_dma && + (total_len > qup->out_fifo_sz || total_len > qup->in_fifo_sz)) { + qup->use_dma = true; + } else { + qup->blk.is_tx_blk_mode = max_tx_len > qup->out_fifo_sz - + QUP_MAX_TAGS_LEN; + qup->blk.is_rx_blk_mode = max_rx_len > qup->in_fifo_sz - + READ_RX_TAGS_LEN; + } + + return 0; +} + +static int qup_i2c_xfer_v2(struct i2c_adapter *adap, + struct i2c_msg msgs[], + int num) +{ + struct qup_i2c_dev *qup = i2c_get_adapdata(adap); + int ret, idx = 0; + + qup->bus_err = 0; + qup->qup_err = 0; + + ret = pm_runtime_get_sync(qup->dev); + if (ret < 0) + goto out; + + ret = qup_i2c_determine_mode_v2(qup, msgs, num); + if (ret) + goto out; + + writel(1, qup->base + QUP_SW_RESET); + ret = qup_i2c_poll_state(qup, QUP_RESET_STATE); + if (ret) + goto out; + + /* Configure QUP as I2C mini core */ + writel(I2C_MINI_CORE | I2C_N_VAL_V2, qup->base + QUP_CONFIG); + writel(QUP_V2_TAGS_EN, qup->base + QUP_I2C_MASTER_GEN); + + if (qup_i2c_poll_state_i2c_master(qup)) { + ret = -EIO; + goto out; + } + + if (qup->use_dma) { + reinit_completion(&qup->xfer); + ret = qup_i2c_bam_xfer(adap, &msgs[0], num); + qup->use_dma = false; + } else { + qup_i2c_conf_mode_v2(qup); + + for (idx = 0; idx < num; idx++) { + qup->msg = &msgs[idx]; + qup->is_last = idx == (num - 1); + + ret = qup_i2c_xfer_v2_msg(qup, idx, + !!(msgs[idx].flags & I2C_M_RD)); + if (ret) + break; + } + qup->msg = NULL; + } + + if (!ret) + ret = qup_i2c_bus_active(qup, ONE_BYTE); + + if (!ret) + qup_i2c_change_state(qup, QUP_RESET_STATE); + + if (ret == 0) + ret = num; +out: + pm_runtime_mark_last_busy(qup->dev); + pm_runtime_put_autosuspend(qup->dev); + + return ret; +} + +static u32 qup_i2c_func(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL_ALL & ~I2C_FUNC_SMBUS_QUICK); +} + +static const struct i2c_algorithm qup_i2c_algo = { + .master_xfer = qup_i2c_xfer, + .functionality = qup_i2c_func, +}; + +static const struct i2c_algorithm qup_i2c_algo_v2 = { + .master_xfer = qup_i2c_xfer_v2, + .functionality = qup_i2c_func, +}; + +/* + * The QUP block will issue a NACK and STOP on the bus when reaching + * the end of the read, the length of the read is specified as one byte + * which limits the possible read to 256 (QUP_READ_LIMIT) bytes. + */ +static const struct i2c_adapter_quirks qup_i2c_quirks = { + .flags = I2C_AQ_NO_ZERO_LEN, + .max_read_len = QUP_READ_LIMIT, +}; + +static const struct i2c_adapter_quirks qup_i2c_quirks_v2 = { + .flags = I2C_AQ_NO_ZERO_LEN, +}; + +static void qup_i2c_enable_clocks(struct qup_i2c_dev *qup) +{ + clk_prepare_enable(qup->clk); + clk_prepare_enable(qup->pclk); +} + +static void qup_i2c_disable_clocks(struct qup_i2c_dev *qup) +{ + u32 config; + + qup_i2c_change_state(qup, QUP_RESET_STATE); + clk_disable_unprepare(qup->clk); + config = readl(qup->base + QUP_CONFIG); + config |= QUP_CLOCK_AUTO_GATE; + writel(config, qup->base + QUP_CONFIG); + clk_disable_unprepare(qup->pclk); +} + +static const struct acpi_device_id qup_i2c_acpi_match[] = { + { "QCOM8010"}, + { }, +}; +MODULE_DEVICE_TABLE(acpi, qup_i2c_acpi_match); + +static int qup_i2c_probe(struct platform_device *pdev) +{ + static const int blk_sizes[] = {4, 16, 32}; + struct qup_i2c_dev *qup; + unsigned long one_bit_t; + u32 io_mode, hw_ver, size; + int ret, fs_div, hs_div; + u32 src_clk_freq = DEFAULT_SRC_CLK; + u32 clk_freq = DEFAULT_CLK_FREQ; + int blocks; + bool is_qup_v1; + + qup = devm_kzalloc(&pdev->dev, sizeof(*qup), GFP_KERNEL); + if (!qup) + return -ENOMEM; + + qup->dev = &pdev->dev; + init_completion(&qup->xfer); + platform_set_drvdata(pdev, qup); + + if (scl_freq) { + dev_notice(qup->dev, "Using override frequency of %u\n", scl_freq); + clk_freq = scl_freq; + } else { + ret = device_property_read_u32(qup->dev, "clock-frequency", &clk_freq); + if (ret) { + dev_notice(qup->dev, "using default clock-frequency %d", + DEFAULT_CLK_FREQ); + } + } + + if (of_device_is_compatible(pdev->dev.of_node, "qcom,i2c-qup-v1.1.1")) { + qup->adap.algo = &qup_i2c_algo; + qup->adap.quirks = &qup_i2c_quirks; + is_qup_v1 = true; + } else { + qup->adap.algo = &qup_i2c_algo_v2; + qup->adap.quirks = &qup_i2c_quirks_v2; + is_qup_v1 = false; + if (acpi_match_device(qup_i2c_acpi_match, qup->dev)) + goto nodma; + else + ret = qup_i2c_req_dma(qup); + + if (ret == -EPROBE_DEFER) + goto fail_dma; + else if (ret != 0) + goto nodma; + + qup->max_xfer_sg_len = (MX_BLOCKS << 1); + blocks = (MX_DMA_BLOCKS << 1) + 1; + qup->btx.sg = devm_kcalloc(&pdev->dev, + blocks, sizeof(*qup->btx.sg), + GFP_KERNEL); + if (!qup->btx.sg) { + ret = -ENOMEM; + goto fail_dma; + } + sg_init_table(qup->btx.sg, blocks); + + qup->brx.sg = devm_kcalloc(&pdev->dev, + blocks, sizeof(*qup->brx.sg), + 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->start_tag.start = devm_kzalloc(&pdev->dev, + size, GFP_KERNEL); + if (!qup->start_tag.start) { + ret = -ENOMEM; + goto fail_dma; + } + + qup->brx.tag.start = devm_kzalloc(&pdev->dev, 2, GFP_KERNEL); + if (!qup->brx.tag.start) { + ret = -ENOMEM; + goto fail_dma; + } + + qup->btx.tag.start = devm_kzalloc(&pdev->dev, 2, GFP_KERNEL); + if (!qup->btx.tag.start) { + ret = -ENOMEM; + goto fail_dma; + } + qup->is_dma = true; + } + +nodma: + /* We support frequencies up to FAST Mode Plus (1MHz) */ + if (!clk_freq || clk_freq > I2C_MAX_FAST_MODE_PLUS_FREQ) { + dev_err(qup->dev, "clock frequency not supported %d\n", + clk_freq); + ret = -EINVAL; + goto fail_dma; + } + + qup->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(qup->base)) { + ret = PTR_ERR(qup->base); + goto fail_dma; + } + + qup->irq = platform_get_irq(pdev, 0); + if (qup->irq < 0) { + ret = qup->irq; + goto fail_dma; + } + + if (has_acpi_companion(qup->dev)) { + ret = device_property_read_u32(qup->dev, + "src-clock-hz", &src_clk_freq); + if (ret) { + dev_notice(qup->dev, "using default src-clock-hz %d", + DEFAULT_SRC_CLK); + } + ACPI_COMPANION_SET(&qup->adap.dev, ACPI_COMPANION(qup->dev)); + } else { + qup->clk = devm_clk_get(qup->dev, "core"); + if (IS_ERR(qup->clk)) { + dev_err(qup->dev, "Could not get core clock\n"); + ret = PTR_ERR(qup->clk); + goto fail_dma; + } + + qup->pclk = devm_clk_get(qup->dev, "iface"); + if (IS_ERR(qup->pclk)) { + dev_err(qup->dev, "Could not get iface clock\n"); + ret = PTR_ERR(qup->pclk); + goto fail_dma; + } + qup_i2c_enable_clocks(qup); + src_clk_freq = clk_get_rate(qup->clk); + } + + /* + * Bootloaders might leave a pending interrupt on certain QUP's, + * so we reset the core before registering for interrupts. + */ + writel(1, qup->base + QUP_SW_RESET); + ret = qup_i2c_poll_state_valid(qup); + if (ret) + goto fail; + + ret = devm_request_irq(qup->dev, qup->irq, qup_i2c_interrupt, + IRQF_TRIGGER_HIGH | IRQF_NO_AUTOEN, + "i2c_qup", qup); + if (ret) { + dev_err(qup->dev, "Request %d IRQ failed\n", qup->irq); + goto fail; + } + + hw_ver = readl(qup->base + QUP_HW_VERSION); + dev_dbg(qup->dev, "Revision %x\n", hw_ver); + + io_mode = readl(qup->base + QUP_IO_MODE); + + /* + * The block/fifo size w.r.t. 'actual data' is 1/2 due to 'tag' + * associated with each byte written/received + */ + size = QUP_OUTPUT_BLOCK_SIZE(io_mode); + if (size >= ARRAY_SIZE(blk_sizes)) { + ret = -EIO; + goto fail; + } + qup->out_blk_sz = blk_sizes[size]; + + size = QUP_INPUT_BLOCK_SIZE(io_mode); + if (size >= ARRAY_SIZE(blk_sizes)) { + ret = -EIO; + goto fail; + } + qup->in_blk_sz = blk_sizes[size]; + + if (is_qup_v1) { + /* + * in QUP v1, QUP_CONFIG uses N as 15 i.e 16 bits constitutes a + * single transfer but the block size is in bytes so divide the + * in_blk_sz and out_blk_sz by 2 + */ + qup->in_blk_sz /= 2; + qup->out_blk_sz /= 2; + qup->write_tx_fifo = qup_i2c_write_tx_fifo_v1; + qup->read_rx_fifo = qup_i2c_read_rx_fifo_v1; + qup->write_rx_tags = qup_i2c_write_rx_tags_v1; + } else { + qup->write_tx_fifo = qup_i2c_write_tx_fifo_v2; + qup->read_rx_fifo = qup_i2c_read_rx_fifo_v2; + qup->write_rx_tags = qup_i2c_write_rx_tags_v2; + } + + size = QUP_OUTPUT_FIFO_SIZE(io_mode); + qup->out_fifo_sz = qup->out_blk_sz * (2 << size); + + size = QUP_INPUT_FIFO_SIZE(io_mode); + qup->in_fifo_sz = qup->in_blk_sz * (2 << size); + + hs_div = 3; + if (clk_freq <= I2C_MAX_STANDARD_MODE_FREQ) { + fs_div = ((src_clk_freq / clk_freq) / 2) - 3; + qup->clk_ctl = (hs_div << 8) | (fs_div & 0xff); + } else { + /* 33%/66% duty cycle */ + fs_div = ((src_clk_freq / clk_freq) - 6) * 2 / 3; + qup->clk_ctl = ((fs_div / 2) << 16) | (hs_div << 8) | (fs_div & 0xff); + } + + /* + * Time it takes for a byte to be clocked out on the bus. + * Each byte takes 9 clock cycles (8 bits + 1 ack). + */ + 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_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, + qup->out_blk_sz, qup->out_fifo_sz); + + i2c_set_adapdata(&qup->adap, qup); + qup->adap.dev.parent = qup->dev; + qup->adap.dev.of_node = pdev->dev.of_node; + qup->is_last = true; + + strscpy(qup->adap.name, "QUP I2C adapter", sizeof(qup->adap.name)); + + pm_runtime_set_autosuspend_delay(qup->dev, MSEC_PER_SEC); + pm_runtime_use_autosuspend(qup->dev); + pm_runtime_set_active(qup->dev); + pm_runtime_enable(qup->dev); + + ret = i2c_add_adapter(&qup->adap); + if (ret) + goto fail_runtime; + + return 0; + +fail_runtime: + pm_runtime_disable(qup->dev); + 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; +} + +static int qup_i2c_remove(struct platform_device *pdev) +{ + struct qup_i2c_dev *qup = platform_get_drvdata(pdev); + + if (qup->is_dma) { + 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); + pm_runtime_disable(qup->dev); + pm_runtime_set_suspended(qup->dev); + return 0; +} + +#ifdef CONFIG_PM +static int qup_i2c_pm_suspend_runtime(struct device *device) +{ + struct qup_i2c_dev *qup = dev_get_drvdata(device); + + dev_dbg(device, "pm_runtime: suspending...\n"); + qup_i2c_disable_clocks(qup); + return 0; +} + +static int qup_i2c_pm_resume_runtime(struct device *device) +{ + struct qup_i2c_dev *qup = dev_get_drvdata(device); + + dev_dbg(device, "pm_runtime: resuming...\n"); + qup_i2c_enable_clocks(qup); + return 0; +} +#endif + +#ifdef CONFIG_PM_SLEEP +static int qup_i2c_suspend(struct device *device) +{ + if (!pm_runtime_suspended(device)) + return qup_i2c_pm_suspend_runtime(device); + return 0; +} + +static int qup_i2c_resume(struct device *device) +{ + qup_i2c_pm_resume_runtime(device); + pm_runtime_mark_last_busy(device); + pm_request_autosuspend(device); + return 0; +} +#endif + +static const struct dev_pm_ops qup_i2c_qup_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS( + qup_i2c_suspend, + qup_i2c_resume) + SET_RUNTIME_PM_OPS( + qup_i2c_pm_suspend_runtime, + qup_i2c_pm_resume_runtime, + NULL) +}; + +static const struct of_device_id qup_i2c_dt_match[] = { + { .compatible = "qcom,i2c-qup-v1.1.1" }, + { .compatible = "qcom,i2c-qup-v2.1.1" }, + { .compatible = "qcom,i2c-qup-v2.2.1" }, + {} +}; +MODULE_DEVICE_TABLE(of, qup_i2c_dt_match); + +static struct platform_driver qup_i2c_driver = { + .probe = qup_i2c_probe, + .remove = qup_i2c_remove, + .driver = { + .name = "i2c_qup", + .pm = &qup_i2c_qup_pm_ops, + .of_match_table = qup_i2c_dt_match, + .acpi_match_table = ACPI_PTR(qup_i2c_acpi_match), + }, +}; + +module_platform_driver(qup_i2c_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:i2c_qup"); |