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linux/drivers/i2c/busses/i2c-qup.c
Abhishek Sahu 7545c7dba1 i2c: qup: reorganization of driver code to remove polling for qup v2 
Following are the major issues in current driver code

1. The current driver simply assumes the transfer completion
   whenever its gets any non-error interrupts and then simply do the
   polling of available/free bytes in FIFO.
2. The block mode is not working properly since no handling in
   being done for OUT_BLOCK_WRITE_REQ and IN_BLOCK_READ_READ.
3. An i2c transfer can contain multiple message and QUP v2
   supports reconfiguration during run in which the mode should be same
   for all the sub transfer. Currently the mode is being programmed
   before every sub transfer which is functionally wrong. If one message
   is less than FIFO length and other message is greater than FIFO
   length, then transfers will fail.

Because of above, i2c v2 transfers of size greater than 64 are failing
with following error message

	i2c_qup 78b6000.i2c: timeout for fifo out full

To make block mode working properly and move to use the interrupts
instead of polling, major code reorganization is required. Following
are the major changes done in this patch

1. Remove the polling of TX FIFO free space and RX FIFO available
   bytes and move to interrupts completely. QUP has QUP_MX_OUTPUT_DONE,
   QUP_MX_INPUT_DONE, OUT_BLOCK_WRITE_REQ and IN_BLOCK_READ_REQ
   interrupts to handle FIFO’s properly so check all these interrupts.
2. Determine the mode for transfer before starting by checking
   all the tx/rx data length in each message. The complete message can be
   transferred either in DMA mode or Programmed IO by FIFO/Block mode.
   in DMA mode, both tx and rx uses same mode but in PIO mode, the TX and
   RX can be in different mode.
3. During write, For FIFO mode, TX FIFO can be directly written
   without checking for FIFO space. For block mode, the QUP will generate
   OUT_BLOCK_WRITE_REQ interrupt whenever it has block size of available
   space.
4. During read, both TX and RX FIFO will be used. TX will be used
   for writing tags and RX will be used for receiving the data. In QUP,
   TX and RX can operate in separate mode so configure modes accordingly.
5. For read FIFO mode, wait for QUP_MX_INPUT_DONE interrupt which
   will be generated after all the bytes have been copied in RX FIFO. For
   read Block mode, QUP will generate IN_BLOCK_READ_REQ interrupts
   whenever it has block size of available data.
6. Split the transfer in chunk of one QUP block size(256 bytes)
   and schedule each block separately. QUP v2 supports reconfiguration
   during run in which QUP can transfer multiple blocks without issuing a
   stop events.
7. Port the SMBus block read support for new code changes.

Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-24 13:21:02 +01:00

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// 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 100000
#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
/*
* 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 = msg->addr << 1;
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_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_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_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, 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);
if (qup_i2c_change_state(qup, QUP_RUN_STATE)) {
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 ? true : false;
blk->is_rx_blk_mode =
blk->total_rx_len > qup->in_fifo_sz ? true : false;
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 (msgs[idx].len == 0) {
ret = -EINVAL;
goto out;
}
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 reamining 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].len == 0)
return -EINVAL;
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 ? true : false;
qup->blk.is_rx_blk_mode = max_rx_len > qup->in_fifo_sz -
READ_RX_TAGS_LEN ? true : false;
}
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 & ~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 = {
.max_read_len = QUP_READ_LIMIT,
};
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 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;
struct resource *res;
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);
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;
is_qup_v1 = false;
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_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->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 (400KHz) */
if (!clk_freq || clk_freq > 400000) {
dev_err(qup->dev, "clock frequency not supported %d\n",
clk_freq);
return -EINVAL;
}
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
qup->base = devm_ioremap_resource(qup->dev, res);
if (IS_ERR(qup->base))
return PTR_ERR(qup->base);
qup->irq = platform_get_irq(pdev, 0);
if (qup->irq < 0) {
dev_err(qup->dev, "No IRQ defined\n");
return qup->irq;
}
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");
return PTR_ERR(qup->clk);
}
qup->pclk = devm_clk_get(qup->dev, "iface");
if (IS_ERR(qup->pclk)) {
dev_err(qup->dev, "Could not get iface clock\n");
return PTR_ERR(qup->pclk);
}
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, "i2c_qup", qup);
if (ret) {
dev_err(qup->dev, "Request %d IRQ failed\n", qup->irq);
goto fail;
}
disable_irq(qup->irq);
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);
fs_div = ((src_clk_freq / clk_freq) / 2) - 3;
hs_div = 3;
qup->clk_ctl = (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;
strlcpy(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);
#if IS_ENABLED(CONFIG_ACPI)
static const struct acpi_device_id qup_i2c_acpi_match[] = {
{ "QCOM8010"},
{ },
};
MODULE_DEVICE_TABLE(acpi, qup_i2c_acpi_match);
#endif
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");
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