Hello Christophe,
> Subject: Re: [PATCH v10 2/2] i2c: aspeed: support ast2600 i2c new register
> mode driver
>
> (resending, my mail client removed some addresses. Sorry for the duplicated
> message for the others)
>
>
> Le 15/04/2023 à 03:28, Ryan Chen a écrit :
> > Add i2c new register mode driver to support AST2600 i2c
> > new register mode. AST2600 i2c controller have legacy and
> > new register mode. The new register mode have global register
> > support 4 base clock for scl clock selection, and new clock
> > divider mode. The i2c new register mode have separate register
> > set to control i2c master and slave.
> >
> > Signed-off-by: Ryan Chen <ryan_chen@xxxxxxxxxxxxxx>
> > ---
>
> [...]
>
> > +static u8 ast2600_i2c_recover_bus(struct ast2600_i2c_bus *i2c_bus)
> > +{
> > + int ret = 0;
> > + u32 ctrl;
> > + u32 state;
> > + int r;
> > +
> > + dev_dbg(i2c_bus->dev, "%d-bus recovery bus [%x]\n",
> i2c_bus->adap.nr,
> > + readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF));
> > +
> > + ctrl = readl(i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
> > +
> > + writel(ctrl & ~(AST2600_I2CC_MASTER_EN |
> AST2600_I2CC_SLAVE_EN),
> > + i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
> > +
> > + writel(readl(i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL) |
> AST2600_I2CC_MASTER_EN,
> > + i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
> > +
> > + reinit_completion(&i2c_bus->cmd_complete);
> > + i2c_bus->cmd_err = 0;
> > +
> > + /* Check 0x14's SDA and SCL status */
> > + state = readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF);
> > + if (!(state & AST2600_I2CC_SDA_LINE_STS) && (state &
> AST2600_I2CC_SCL_LINE_STS)) {
> > + writel(AST2600_I2CM_RECOVER_CMD_EN, i2c_bus->reg_base +
> AST2600_I2CM_CMD_STS);
> > + r = wait_for_completion_timeout(&i2c_bus->cmd_complete,
> i2c_bus->adap.timeout);
> > + if (r == 0) {
> > + dev_dbg(i2c_bus->dev, "recovery timed out\n");
> > + ret = -ETIMEDOUT;
> > + } else {
> > + if (i2c_bus->cmd_err) {
> > + dev_dbg(i2c_bus->dev, "recovery error\n");
> > + ret = -EPROTO;
> > + }
> > + }
> > + }
> > +
> > + dev_dbg(i2c_bus->dev, "Recovery done [%x]\n",
> > + readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF));
> > + if (readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF) &
> AST2600_I2CC_BUS_BUSY_STS) {
> > + dev_dbg(i2c_bus->dev, "Can't recovery bus [%x]\n",
>
> recover?
Sorry, Do you mean modify the wording "Can’t recover bus"?
>
> > + readl(i2c_bus->reg_base +
> AST2600_I2CC_STS_AND_BUFF));
> > + ret = -EPROTO;
> > + }
> > +
> > + writel(ctrl, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
> > + return ret;
> > +}
> > +
> > +#ifdef CONFIG_I2C_SLAVE
> > +static void ast2600_i2c_slave_packet_dma_irq(struct ast2600_i2c_bus
> *i2c_bus, u32 sts)
> > +{
> > + int slave_rx_len;
> > + u32 cmd = 0;
> > + u8 value;
> > + int i = 0;
>
> No need to init
Will remove init.
>
> > +
> > + sts &= ~(AST2600_I2CS_SLAVE_PENDING);
> > + /* Handle i2c slave timeout condition */
> > + if (AST2600_I2CS_INACTIVE_TO & sts) {
> > + cmd = SLAVE_TRIGGER_CMD;
> > + cmd |= AST2600_I2CS_RX_DMA_EN;
> > +
> writel(AST2600_I2CS_SET_RX_DMA_LEN(I2C_SLAVE_MSG_BUF_SIZE),
> > + i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
> > + writel(cmd, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
> > + writel(AST2600_I2CS_PKT_DONE, i2c_bus->reg_base +
> AST2600_I2CS_ISR);
> > + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_STOP, &value);
> > + return;
> > + }
> > +
> > + sts &= ~(AST2600_I2CS_PKT_DONE | AST2600_I2CS_PKT_ERROR);
> > +
> > + switch (sts) {
> > + case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE |
> AST2600_I2CS_WAIT_RX_DMA:
> > + case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_WAIT_RX_DMA:
> > + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_WRITE_REQUESTED,
> &value);
> > + slave_rx_len =
> AST2600_I2C_GET_RX_DMA_LEN(readl(i2c_bus->reg_base +
> > + AST2600_I2CS_DMA_LEN_STS));
> > + for (i = 0; i < slave_rx_len; i++) {
> > + i2c_slave_event(i2c_bus->slave,
> I2C_SLAVE_WRITE_RECEIVED,
> > + &i2c_bus->slave_dma_buf[i]);
> > + }
> > +
> writel(AST2600_I2CS_SET_RX_DMA_LEN(I2C_SLAVE_MSG_BUF_SIZE),
> > + i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
> > + cmd = SLAVE_TRIGGER_CMD | AST2600_I2CS_RX_DMA_EN;
> > + break;
> > + case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_STOP:
> > + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_STOP, &value);
> > +
> writel(AST2600_I2CS_SET_RX_DMA_LEN(I2C_SLAVE_MSG_BUF_SIZE),
> > + i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
> > + cmd = SLAVE_TRIGGER_CMD | AST2600_I2CS_RX_DMA_EN;
> > + break;
> > + case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE_NAK
> |
> > + AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
> > + case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_WAIT_RX_DMA
> |
> > + AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
> > + case AST2600_I2CS_RX_DONE_NAK | AST2600_I2CS_RX_DONE |
> AST2600_I2CS_STOP:
> > + case AST2600_I2CS_RX_DONE | AST2600_I2CS_WAIT_RX_DMA |
> AST2600_I2CS_STOP:
> > + case AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
> > + case AST2600_I2CS_RX_DONE | AST2600_I2CS_WAIT_RX_DMA:
> > + case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE |
> AST2600_I2CS_STOP:
> > + if (sts & AST2600_I2CS_SLAVE_MATCH)
> > + i2c_slave_event(i2c_bus->slave,
> I2C_SLAVE_WRITE_REQUESTED, &value);
> > +
> > + slave_rx_len =
> AST2600_I2C_GET_RX_DMA_LEN(readl(i2c_bus->reg_base +
> > + AST2600_I2CS_DMA_LEN_STS));
> > + for (i = 0; i < slave_rx_len; i++) {
> > + i2c_slave_event(i2c_bus->slave,
> I2C_SLAVE_WRITE_RECEIVED,
> > + &i2c_bus->slave_dma_buf[i]);
> > + }
> > +
> writel(AST2600_I2CS_SET_RX_DMA_LEN(I2C_SLAVE_MSG_BUF_SIZE),
> > + i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
> > + if (sts & AST2600_I2CS_STOP)
> > + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_STOP, &value);
> > + cmd = SLAVE_TRIGGER_CMD | AST2600_I2CS_RX_DMA_EN;
> > + break;
> > +
> > + /* it is Mw data Mr coming -> it need send tx */
> > + case AST2600_I2CS_RX_DONE | AST2600_I2CS_WAIT_TX_DMA:
> > + case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE |
> AST2600_I2CS_WAIT_TX_DMA:
> > + /* it should be repeat start read */
> > + if (sts & AST2600_I2CS_SLAVE_MATCH)
> > + i2c_slave_event(i2c_bus->slave,
> I2C_SLAVE_WRITE_REQUESTED, &value);
> > +
> > + slave_rx_len =
> AST2600_I2C_GET_RX_DMA_LEN(readl(i2c_bus->reg_base +
> > + AST2600_I2CS_DMA_LEN_STS));
> > + for (i = 0; i < slave_rx_len; i++) {
> > + i2c_slave_event(i2c_bus->slave,
> I2C_SLAVE_WRITE_RECEIVED,
> > + &i2c_bus->slave_dma_buf[i]);
> > + }
> > + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_READ_REQUESTED,
> > + &i2c_bus->slave_dma_buf[0]);
> > + writel(0, i2c_bus->reg_base + AST2600_I2CS_DMA_LEN_STS);
> > + writel(AST2600_I2CS_SET_TX_DMA_LEN(1),
> > + i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
> > + cmd = SLAVE_TRIGGER_CMD | AST2600_I2CS_TX_DMA_EN;
> > + break;
> > + case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_WAIT_TX_DMA:
> > + /* First Start read */
> > + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_READ_REQUESTED,
> > + &i2c_bus->slave_dma_buf[0]);
> > + writel(AST2600_I2CS_SET_TX_DMA_LEN(1),
> > + i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
> > + cmd = SLAVE_TRIGGER_CMD | AST2600_I2CS_TX_DMA_EN;
> > + break;
> > + case AST2600_I2CS_WAIT_TX_DMA:
> > + /* it should be next start read */
> > + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_READ_PROCESSED,
> > + &i2c_bus->slave_dma_buf[0]);
> > + writel(0, i2c_bus->reg_base + AST2600_I2CS_DMA_LEN_STS);
> > + writel(AST2600_I2CS_SET_TX_DMA_LEN(1),
> > + i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
> > + cmd = SLAVE_TRIGGER_CMD | AST2600_I2CS_TX_DMA_EN;
> > + break;
>
> Having a new line or not after breaks is not consistent.
Will update for consistent.
>
> > +
> > + case AST2600_I2CS_TX_NAK | AST2600_I2CS_STOP:
> > + /* it just tx complete */
> > + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_STOP, &value);
> > + writel(0, i2c_bus->reg_base + AST2600_I2CS_DMA_LEN_STS);
> > +
> writel(AST2600_I2CS_SET_RX_DMA_LEN(I2C_SLAVE_MSG_BUF_SIZE),
> > + i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
> > + cmd = SLAVE_TRIGGER_CMD | AST2600_I2CS_RX_DMA_EN;
> > + break;
> > + case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE:
> > + cmd = 0;
> > + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_WRITE_REQUESTED,
> &value);
> > + break;
> > + case AST2600_I2CS_STOP:
> > + cmd = 0;
> > + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_STOP, &value);
> > + break;
> > + default:
> > + dev_dbg(i2c_bus->dev, "unhandled slave isr case %x, sts
> %x\n", sts,
> > + readl(i2c_bus->reg_base +
> AST2600_I2CC_STS_AND_BUFF));
> > + break;
> > + }
> > +
> > + if (cmd)
> > + writel(cmd, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
> > + writel(AST2600_I2CS_PKT_DONE, i2c_bus->reg_base +
> AST2600_I2CS_ISR);
> > + readl(i2c_bus->reg_base + AST2600_I2CS_ISR);
> > +}
> > +
> > +static void ast2600_i2c_slave_packet_buff_irq(struct ast2600_i2c_bus
> *i2c_bus, u32 sts)
> > +{
> > + int slave_rx_len = 0;
> > + u32 cmd = 0;
> > + u8 value;
> > + int i = 0;
>
> No need to init;
Will remove init
>
> > +
> > + /* due to master slave is common buffer, so need force the
> master stop not issue */
> > + if (readl(i2c_bus->reg_base + AST2600_I2CM_CMD_STS) & 0xffff) {
> > + writel(0, i2c_bus->reg_base + AST2600_I2CM_CMD_STS);
> > + i2c_bus->cmd_err = -EBUSY;
> > + writel(0, i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
> > + complete(&i2c_bus->cmd_complete);
> > + }
> > +
> > + /* Handle i2c slave timeout condition */
> > + if (AST2600_I2CS_INACTIVE_TO & sts) {
> > + writel(SLAVE_TRIGGER_CMD, i2c_bus->reg_base +
> AST2600_I2CS_CMD_STS);
> > + writel(AST2600_I2CS_PKT_DONE, i2c_bus->reg_base +
> AST2600_I2CS_ISR);
> > + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_STOP, &value);
> > + i2c_bus->slave_operate = 0;
> > + return;
> > + }
> > +
> > + sts &= ~(AST2600_I2CS_PKT_DONE | AST2600_I2CS_PKT_ERROR);
> > +
> > + if (sts & AST2600_I2CS_SLAVE_MATCH)
> > + i2c_bus->slave_operate = 1;
> > +
> > + switch (sts) {
> > + case AST2600_I2CS_SLAVE_PENDING |
> AST2600_I2CS_WAIT_RX_DMA |
> > + AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE |
> AST2600_I2CS_STOP:
> > + case AST2600_I2CS_SLAVE_PENDING |
> > + AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE |
> AST2600_I2CS_STOP:
> > + case AST2600_I2CS_SLAVE_PENDING |
> > + AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_STOP:
> > + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_STOP, &value);
> > + fallthrough;
> > + case AST2600_I2CS_SLAVE_PENDING |
> > + AST2600_I2CS_WAIT_RX_DMA | AST2600_I2CS_SLAVE_MATCH
> |
> AST2600_I2CS_RX_DONE:
> > + case AST2600_I2CS_WAIT_RX_DMA | AST2600_I2CS_SLAVE_MATCH
> |
> AST2600_I2CS_RX_DONE:
> > + case AST2600_I2CS_WAIT_RX_DMA | AST2600_I2CS_SLAVE_MATCH:
> > + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_WRITE_REQUESTED,
> &value);
> > + cmd = SLAVE_TRIGGER_CMD;
> > + if (sts & AST2600_I2CS_RX_DONE) {
> > + slave_rx_len =
> AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
> > + AST2600_I2CC_BUFF_CTRL));
> > + for (i = 0; i < slave_rx_len; i++) {
> > + value = readb(i2c_bus->buf_base + 0x10 + i);
> > + i2c_slave_event(i2c_bus->slave,
> I2C_SLAVE_WRITE_RECEIVED, &value);
> > + }
> > + }
> > + if (readl(i2c_bus->reg_base + AST2600_I2CS_CMD_STS) &
> AST2600_I2CS_RX_BUFF_EN)
> > + cmd = 0;
> > + else
> > + cmd = SLAVE_TRIGGER_CMD |
> AST2600_I2CS_RX_BUFF_EN;
> > +
> > + writel(AST2600_I2CC_SET_RX_BUF_LEN(i2c_bus->buf_size),
> > + i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
> > + break;
> > + case AST2600_I2CS_WAIT_RX_DMA | AST2600_I2CS_RX_DONE:
> > + cmd = SLAVE_TRIGGER_CMD;
> > + slave_rx_len =
> AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
> > + AST2600_I2CC_BUFF_CTRL));
> > + for (i = 0; i < slave_rx_len; i++) {
> > + value = readb(i2c_bus->buf_base + 0x10 + i);
> > + i2c_slave_event(i2c_bus->slave,
> I2C_SLAVE_WRITE_RECEIVED, &value);
> > + }
> > + cmd |= AST2600_I2CS_RX_BUFF_EN;
> > + writel(AST2600_I2CC_SET_RX_BUF_LEN(i2c_bus->buf_size),
> > + i2c_bus->reg_base +
> AST2600_I2CC_BUFF_CTRL);
> > + break;
> > + case AST2600_I2CS_SLAVE_PENDING |
> AST2600_I2CS_WAIT_RX_DMA |
> > + AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
> > + cmd = SLAVE_TRIGGER_CMD;
> > + slave_rx_len =
> AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
> > + AST2600_I2CC_BUFF_CTRL));
> > + for (i = 0; i < slave_rx_len; i++) {
> > + value = readb(i2c_bus->buf_base + 0x10 + i);
> > + i2c_slave_event(i2c_bus->slave,
> I2C_SLAVE_WRITE_RECEIVED, &value);
> > + }
> > + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_STOP, &value);
> > + cmd |= AST2600_I2CS_RX_BUFF_EN;
> > + writel(AST2600_I2CC_SET_RX_BUF_LEN(i2c_bus->buf_size),
> > + i2c_bus->reg_base +
> AST2600_I2CC_BUFF_CTRL);
> > + break;
> > +
>
> Having a new line or not after breaks is not consistent.
Will update for consistent.
>
> > + case AST2600_I2CS_SLAVE_PENDING | AST2600_I2CS_RX_DONE |
> AST2600_I2CS_STOP:
> > + cmd = SLAVE_TRIGGER_CMD;
> > + slave_rx_len =
> AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
> > + AST2600_I2CC_BUFF_CTRL));
> > + for (i = 0; i < slave_rx_len; i++) {
> > + value = readb(i2c_bus->buf_base + 0x10 + i);
> > + i2c_slave_event(i2c_bus->slave,
> I2C_SLAVE_WRITE_RECEIVED, &value);
> > + }
> > + /* workaround for avoid next start with len != 0 */
> > + writel(BIT(0), i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
> > + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_STOP, &value);
> > + break;
> > +
> > + case AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
> > + cmd = SLAVE_TRIGGER_CMD;
> > + slave_rx_len =
> AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
> > + AST2600_I2CC_BUFF_CTRL));
> > + for (i = 0; i < slave_rx_len; i++) {
> > + value = readb(i2c_bus->buf_base + 0x10 + i);
> > + i2c_slave_event(i2c_bus->slave,
> I2C_SLAVE_WRITE_RECEIVED, &value);
> > + }
> > + /* workaround for avoid next start with len != 0 */
> > + writel(BIT(0), i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
> > + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_STOP, &value);
> > + break;
> > + case AST2600_I2CS_WAIT_TX_DMA | AST2600_I2CS_SLAVE_MATCH:
> > + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_READ_REQUESTED,
> &value);
> > + writeb(value, i2c_bus->buf_base);
> > + writel(AST2600_I2CC_SET_TX_BUF_LEN(1),
> > + i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
> > + cmd = SLAVE_TRIGGER_CMD | AST2600_I2CS_TX_BUFF_EN;
> > + break;
> > + case AST2600_I2CS_WAIT_TX_DMA | AST2600_I2CS_RX_DONE:
> > + case AST2600_I2CS_WAIT_TX_DMA:
> > + if (sts & AST2600_I2CS_RX_DONE) {
> > + slave_rx_len =
> AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
> > + AST2600_I2CC_BUFF_CTRL));
> > + for (i = 0; i < slave_rx_len; i++) {
> > + value = readb(i2c_bus->buf_base + 0x10 + i);
> > + i2c_slave_event(i2c_bus->slave,
> I2C_SLAVE_WRITE_RECEIVED, &value);
> > + }
> > + i2c_slave_event(i2c_bus->slave,
> I2C_SLAVE_READ_REQUESTED, &value);
> > + } else {
> > + i2c_slave_event(i2c_bus->slave,
> I2C_SLAVE_READ_PROCESSED, &value);
> > + }
> > + writeb(value, i2c_bus->buf_base);
> > + writel(AST2600_I2CC_SET_TX_BUF_LEN(1),
> > + i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
> > + cmd = SLAVE_TRIGGER_CMD | AST2600_I2CS_TX_BUFF_EN;
> > + break;
> > + /* workaround : trigger the cmd twice to fix next state keep
> 1000000 */
> > + case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE:
> > + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_WRITE_REQUESTED,
> &value);
> > + cmd = SLAVE_TRIGGER_CMD | AST2600_I2CS_RX_BUFF_EN;
> > + writel(cmd, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
> > + break;
> > +
> > + case AST2600_I2CS_TX_NAK | AST2600_I2CS_STOP:
> > + case AST2600_I2CS_STOP:
> > + cmd = SLAVE_TRIGGER_CMD;
> > + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_STOP, &value);
> > + break;
> > + default:
> > + dev_dbg(i2c_bus->dev, "unhandled slave isr case %x, sts
> %x\n", sts,
> > + readl(i2c_bus->reg_base +
> AST2600_I2CC_STS_AND_BUFF));
> > + break;
> > + }
> > +
> > + if (cmd)
> > + writel(cmd, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
> > + writel(AST2600_I2CS_PKT_DONE, i2c_bus->reg_base +
> AST2600_I2CS_ISR);
> > + readl(i2c_bus->reg_base + AST2600_I2CS_ISR);
> > +
> > + if ((sts & AST2600_I2CS_STOP) && !(sts &
> AST2600_I2CS_SLAVE_PENDING))
> > + i2c_bus->slave_operate = 0;
> > +
>
> Nit: unneeded empty line.
Will remove it.
>
> > +}
> > +
> > +static void ast2600_i2c_slave_byte_irq(struct ast2600_i2c_bus
> *i2c_bus, u32 sts)
> > +{
> > + u32 i2c_buff = readl(i2c_bus->reg_base +
> AST2600_I2CC_STS_AND_BUFF);
> > + u32 cmd = AST2600_I2CS_ACTIVE_ALL;
> > + u8 byte_data;
> > + u8 value;
> > +
> > + switch (sts) {
> > + case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE |
> AST2600_I2CS_WAIT_RX_DMA:
> > + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_WRITE_REQUESTED,
> &value);
> > + /* first address match is address */
> > + byte_data = AST2600_I2CC_GET_RX_BUFF(i2c_buff);
> > + break;
> > + case AST2600_I2CS_RX_DONE | AST2600_I2CS_WAIT_RX_DMA:
> > + byte_data = AST2600_I2CC_GET_RX_BUFF(i2c_buff);
> > + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_WRITE_RECEIVED,
> &byte_data);
> > + break;
> > + case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE |
> AST2600_I2CS_WAIT_TX_DMA:
> > + cmd |= AST2600_I2CS_TX_CMD;
> > + byte_data = AST2600_I2CC_GET_RX_BUFF(i2c_buff);
> > + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_READ_REQUESTED,
> &byte_data);
> > + writel(byte_data, i2c_bus->reg_base +
> AST2600_I2CC_STS_AND_BUFF);
> > + break;
> > + case AST2600_I2CS_TX_ACK | AST2600_I2CS_WAIT_TX_DMA:
> > + cmd |= AST2600_I2CS_TX_CMD;
> > + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_READ_PROCESSED,
> &byte_data);
> > + writel(byte_data, i2c_bus->reg_base +
> AST2600_I2CC_STS_AND_BUFF);
> > + break;
> > + case AST2600_I2CS_STOP:
> > + case AST2600_I2CS_STOP | AST2600_I2CS_TX_NAK:
> > + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_STOP, &value);
> > + break;
> > + default:
> > + dev_dbg(i2c_bus->dev, "unhandled pkt isr %x\n", sts);
> > + break;
> > + }
> > + writel(cmd, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
> > + writel(sts, i2c_bus->reg_base + AST2600_I2CS_ISR);
> > + readl(i2c_bus->reg_base + AST2600_I2CS_ISR);
> > +}
> > +
> > +static int ast2600_i2c_slave_irq(struct ast2600_i2c_bus *i2c_bus)
> > +{
> > + u32 ier = readl(i2c_bus->reg_base + AST2600_I2CS_IER);
> > + u32 isr = readl(i2c_bus->reg_base + AST2600_I2CS_ISR);
> > +
> > + if (!(isr & ier))
> > + return 0;
> > +
> > + /* Slave interrupt coming after Master package done
> > + * So need handle master first.
> > + */
> > + if (readl(i2c_bus->reg_base + AST2600_I2CM_ISR) &
> AST2600_I2CM_PKT_DONE)
> > + return 0;
> > +
> > + isr &= ~(AST2600_I2CS_ADDR_INDICATE_MASK);
> > +
> > + if (AST2600_I2CS_ADDR1_NAK & isr)
> > + isr &= ~AST2600_I2CS_ADDR1_NAK;
> > +
> > + if (AST2600_I2CS_ADDR2_NAK & isr)
> > + isr &= ~AST2600_I2CS_ADDR2_NAK;
> > +
> > + if (AST2600_I2CS_ADDR3_NAK & isr)
> > + isr &= ~AST2600_I2CS_ADDR3_NAK;
> > +
> > + if (AST2600_I2CS_ADDR_MASK & isr)
> > + isr &= ~AST2600_I2CS_ADDR_MASK;
> > +
> > + if (AST2600_I2CS_PKT_DONE & isr) {
> > + if (i2c_bus->mode == DMA_MODE)
> > + ast2600_i2c_slave_packet_dma_irq(i2c_bus, isr);
> > + else
> > + ast2600_i2c_slave_packet_buff_irq(i2c_bus, isr);
> > + } else
> > + ast2600_i2c_slave_byte_irq(i2c_bus, isr);
> > +
> > + return 1;
> > +}
> > +#endif
> > +
> > +static int ast2600_i2c_do_start(struct ast2600_i2c_bus *i2c_bus)
> > +{
> > + struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
> > + int xfer_len = 0;
> > + int i = 0;
>
> No need to init.
Will remove init 0.
>
> > + u32 cmd;
> > +
> > + cmd = AST2600_I2CM_PKT_EN |
> AST2600_I2CM_PKT_ADDR(msg->addr) |
> AST2600_I2CM_START_CMD;
> > +
> > + /* send start */
> > + dev_dbg(i2c_bus->dev, "[%d] %sing %d byte%s %s 0x%02x\n",
> > + i2c_bus->msgs_index, msg->flags & I2C_M_RD ? "read" :
> "write",
> > + msg->len, msg->len > 1 ? "s" : "",
> > + msg->flags & I2C_M_RD ? "from" : "to", msg->addr);
> > +
> > + i2c_bus->master_xfer_cnt = 0;
> > + i2c_bus->buf_index = 0;
>
> [...]
>
> > +static int ast2600_i2c_master_xfer(struct i2c_adapter *adap,
> > + struct i2c_msg *msgs, int num)
> > +{
> > + struct ast2600_i2c_bus *i2c_bus = i2c_get_adapdata(adap);
> > + unsigned long timeout;
> > + int ret = 0;
>
> Looks like this initialization is unneeded.
Will remove 0.
>
> > +
> > + /* If bus is busy in a single master environment, attempt
> recovery. */
> > + if (!i2c_bus->multi_master &&
> > + (readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF) &
> AST2600_I2CC_BUS_BUSY_STS)) {
> > + int ret;
>
> No need for an extra 'ret'.
Will remove it.
>
> > +
> > + ret = ast2600_i2c_recover_bus(i2c_bus);
> > + if (ret)
> > + return ret;
> > + }
> > +
> > +#ifdef CONFIG_I2C_SLAVE
> > + if (i2c_bus->mode == BUFF_MODE) {
> > + if (i2c_bus->slave_operate)
> > + return -EBUSY;
> > + /* disable slave isr */
> > + writel(0, i2c_bus->reg_base + AST2600_I2CS_IER);
> > + if (readl(i2c_bus->reg_base + AST2600_I2CS_ISR) ||
> (i2c_bus->slave_operate)) {
> > + writel(AST2600_I2CS_PKT_DONE, i2c_bus->reg_base +
> AST2600_I2CS_IER);
> > + return -EBUSY;
> > + }
> > + }
> > +#endif
> > +
> > + i2c_bus->cmd_err = 0;
> > + i2c_bus->msgs = msgs;
> > + i2c_bus->msgs_index = 0;
> > + i2c_bus->msgs_count = num;
> > + reinit_completion(&i2c_bus->cmd_complete);
> > + ret = ast2600_i2c_do_start(i2c_bus);
> > +#ifdef CONFIG_I2C_SLAVE
> > + /* avoid race condication slave is wait and master wait 1st
> slave operate */
> > + if (i2c_bus->mode == BUFF_MODE)
> > + writel(AST2600_I2CS_PKT_DONE, i2c_bus->reg_base +
> AST2600_I2CS_IER);
> > +#endif
> > + if (ret)
> > + goto master_out;
> > + timeout = wait_for_completion_timeout(&i2c_bus->cmd_complete,
> i2c_bus->adap.timeout);
> > + if (timeout == 0) {
> > + u32 isr = readl(i2c_bus->reg_base + AST2600_I2CM_ISR);
> > + u32 i2c_status = readl(i2c_bus->reg_base +
> AST2600_I2CC_STS_AND_BUFF);
> > +
> > + dev_dbg(i2c_bus->dev, "timeout isr[%x], sts[%x]\n", isr,
> i2c_status);
> > + if (isr || (i2c_status & AST2600_I2CC_TX_DIR_MASK)) {
> > + u32 ctrl = readl(i2c_bus->reg_base +
> AST2600_I2CC_FUN_CTRL);
> > +
> > + writel(0, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
> > + writel(ctrl, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
> > +#ifdef CONFIG_I2C_SLAVE
> > + if (ctrl & AST2600_I2CC_SLAVE_EN) {
> > + u32 cmd = SLAVE_TRIGGER_CMD;
> > +
> > + if (i2c_bus->mode == DMA_MODE) {
> > + cmd |= AST2600_I2CS_RX_DMA_EN;
> > + writel(i2c_bus->slave_dma_addr,
> > + i2c_bus->reg_base +
> AST2600_I2CS_RX_DMA);
> > + writel(i2c_bus->slave_dma_addr,
> > + i2c_bus->reg_base +
> AST2600_I2CS_TX_DMA);
> > +
> writel(AST2600_I2CS_SET_RX_DMA_LEN(I2C_SLAVE_MSG_BUF_SIZE),
> > + i2c_bus->reg_base +
> AST2600_I2CS_DMA_LEN);
> > + } else if (i2c_bus->mode == BUFF_MODE) {
> > + cmd = SLAVE_TRIGGER_CMD;
> > + } else {
> > + cmd &= ~AST2600_I2CS_PKT_MODE_EN;
> > + }
> > + writel(cmd, i2c_bus->reg_base +
> AST2600_I2CS_CMD_STS);
> > + }
> > +#endif
> > + }
> > + ret = -ETIMEDOUT;
> > + } else {
> > + ret = i2c_bus->cmd_err;
> > + }
> > +
> > + dev_dbg(i2c_bus->dev, "bus%d-m: %d end\n", i2c_bus->adap.nr,
> i2c_bus->cmd_err);
> > +
> > +master_out:
> > + if (i2c_bus->mode == DMA_MODE) {
> > + kfree(i2c_bus->master_safe_buf);
> > + i2c_bus->master_safe_buf = NULL;
>
> Alignement.
Sorry, I can't catch the alignment could you help point out or give me example?
>
> > + }
> > +
> > + return ret;
> > +}
> > +
> > +static void ast2600_i2c_init(struct ast2600_i2c_bus *i2c_bus)
> > +{
> > + struct platform_device *pdev = to_platform_device(i2c_bus->dev);
> > + u32 fun_ctrl = AST2600_I2CC_BUS_AUTO_RELEASE |
> AST2600_I2CC_MASTER_EN;
> > +
> > + /* I2C Reset */
> > + writel(0, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
> > +
> > + if (of_property_read_bool(pdev->dev.of_node, "multi-master"))
> > + i2c_bus->multi_master = true;
> > + else
> > + fun_ctrl |= AST2600_I2CC_MULTI_MASTER_DIS;
> > +
> > + /* Enable Master Mode */
> > + writel(fun_ctrl, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
> > + /* disable slave address */
> > + writel(0, i2c_bus->reg_base + AST2600_I2CS_ADDR_CTRL);
> > +
> > + /* Set AC Timing */
> > + writel(ast2600_select_i2c_clock(i2c_bus), i2c_bus->reg_base +
> AST2600_I2CC_AC_TIMING);
> > +
> > + /* Clear Interrupt */
> > + writel(0xfffffff, i2c_bus->reg_base + AST2600_I2CM_ISR);
> > +
> > +#ifdef CONFIG_I2C_SLAVE
> > + /* for memory buffer initial */
> > + if (i2c_bus->mode == DMA_MODE) {
> > + i2c_bus->slave_dma_buf = dma_alloc_coherent(i2c_bus->dev,
> I2C_SLAVE_MSG_BUF_SIZE,
> > + &i2c_bus->slave_dma_addr,
> GFP_KERNEL);
>
> dmam_alloc_coherent() could maybe be used here.
> This would simplify the remove function and avoid some conditional
> compilation.
> This also fixes a leak if i2c_add_adapter() fails in the probe.
>
> It is also likely that doing so, the devm_free_irq() in the remove
> function also becomes redundant and can be removed as well.
>
> > + if (!i2c_bus->slave_dma_buf)
> > + return;
> > + }
> > +
> > + writel(0xfffffff, i2c_bus->reg_base + AST2600_I2CS_ISR);
> > +
> > + if (i2c_bus->mode == BYTE_MODE) {
> > + writel(0xffff, i2c_bus->reg_base + AST2600_I2CS_IER);
> > + } else {
> > + /* Set interrupt generation of I2C slave controller */
> > + writel(AST2600_I2CS_PKT_DONE, i2c_bus->reg_base +
> AST2600_I2CS_IER);
> > + }
> > +#endif
> > +}
> > +
> > +#ifdef CONFIG_I2C_SLAVE
> > +static int ast2600_i2c_reg_slave(struct i2c_client *client)
> > +{
> > + struct ast2600_i2c_bus *i2c_bus =
> i2c_get_adapdata(client->adapter);
> > + u32 cmd = SLAVE_TRIGGER_CMD;
> > +
> > + if (i2c_bus->slave)
> > + return -EINVAL;
> > +
> > + dev_dbg(i2c_bus->dev, "slave addr %x\n", client->addr);
> > +
> > + writel(0, i2c_bus->reg_base + AST2600_I2CS_ADDR_CTRL);
> > + writel(AST2600_I2CC_SLAVE_EN | readl(i2c_bus->reg_base +
> AST2600_I2CC_FUN_CTRL),
> > + i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
> > +
> > + /* trigger rx buffer */
> > + if (i2c_bus->mode == DMA_MODE) {
> > + cmd |= AST2600_I2CS_RX_DMA_EN;
> > + writel(i2c_bus->slave_dma_addr, i2c_bus->reg_base +
> AST2600_I2CS_RX_DMA);
> > + writel(i2c_bus->slave_dma_addr, i2c_bus->reg_base +
> AST2600_I2CS_TX_DMA);
> > +
> writel(AST2600_I2CS_SET_RX_DMA_LEN(I2C_SLAVE_MSG_BUF_SIZE),
> > + i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
> > + } else if (i2c_bus->mode == BUFF_MODE) {
> > + cmd = SLAVE_TRIGGER_CMD;
> > + } else {
> > + cmd &= ~AST2600_I2CS_PKT_MODE_EN;
> > + }
> > +
> > + writel(cmd, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
> > + i2c_bus->slave = client;
> > + /* Set slave addr. */
> > + writel(client->addr | AST2600_I2CS_ADDR1_ENABLE,
> > + i2c_bus->reg_base + AST2600_I2CS_ADDR_CTRL);
>
> Nit: alignement
Sorry, what should I do for alignment.
>
> > +
> > + return 0;
> > +}
> > +
> > +static int ast2600_i2c_unreg_slave(struct i2c_client *slave)
> > +{
> > + struct ast2600_i2c_bus *i2c_bus = i2c_get_adapdata(slave->adapter);
> > +
> > + WARN_ON(!i2c_bus->slave);
> > +
> > + /* Turn off slave mode. */
> > + writel(~AST2600_I2CC_SLAVE_EN & readl(i2c_bus->reg_base +
> AST2600_I2CC_FUN_CTRL),
> > + i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
> > + writel(readl(i2c_bus->reg_base + AST2600_I2CS_ADDR_CTRL) &
> ~AST2600_I2CS_ADDR1_MASK,
> > + i2c_bus->reg_base + AST2600_I2CS_ADDR_CTRL);
> > +
> > + i2c_bus->slave = NULL;
> > +
> > + return 0;
> > +}
> > +#endif
> > +
> > +static u32 ast2600_i2c_functionality(struct i2c_adapter *adap)
> > +{
> > + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
> I2C_FUNC_SMBUS_BLOCK_DATA;
> > +}
> > +
> > +static const struct i2c_algorithm i2c_ast2600_algorithm = {
> > + .master_xfer = ast2600_i2c_master_xfer,
> > +#if IS_ENABLED(CONFIG_I2C_SLAVE)
> > + .reg_slave = ast2600_i2c_reg_slave,
> > + .unreg_slave = ast2600_i2c_unreg_slave,
> > +#endif
> > + .functionality = ast2600_i2c_functionality,
> > +};
> > +
> > +static const struct of_device_id ast2600_i2c_bus_of_table[] = {
> > + {
> > + .compatible = "aspeed,ast2600-i2cv2",
> > + },
> > + {}
> > +};
> > +
> > +MODULE_DEVICE_TABLE(of, ast2600_i2c_bus_of_table);
> > +
> > +static int ast2600_i2c_probe(struct platform_device *pdev)
> > +{
> > + struct device_node *np = pdev->dev.of_node;
> > + struct device *dev = &pdev->dev;
> > + struct ast2600_i2c_bus *i2c_bus;
> > + struct resource *res;
> > + u32 global_ctrl;
> > + int ret = 0;
> > +
> > + i2c_bus = devm_kzalloc(dev, sizeof(*i2c_bus), GFP_KERNEL);
> > + if (!i2c_bus)
> > + return -ENOMEM;
> > +
> > + i2c_bus->reg_base = devm_platform_ioremap_resource(pdev, 0);
> > + if (IS_ERR(i2c_bus->reg_base))
> > + return PTR_ERR(i2c_bus->reg_base);
> > +
> > + i2c_bus->rst = devm_reset_control_get_shared(dev, NULL);
> > + if (IS_ERR(i2c_bus->rst))
> > + return dev_err_probe(dev, PTR_ERR(i2c_bus->rst), "Missing
> reset ctrl\n");
> > +
> > + reset_control_deassert(i2c_bus->rst);
> > +
> > + i2c_bus->global_regs = syscon_regmap_lookup_by_phandle(np,
> "aspeed,global-regs");
> > + if (IS_ERR(i2c_bus->global_regs))
> > + return PTR_ERR(i2c_bus->global_regs);
> > +
> > + regmap_read(i2c_bus->global_regs, AST2600_I2CG_CTRL,
> &global_ctrl);
> > + if ((global_ctrl & AST2600_GLOBAL_INIT) != AST2600_GLOBAL_INIT) {
> > + regmap_write(i2c_bus->global_regs, AST2600_I2CG_CTRL,
> AST2600_GLOBAL_INIT);
> > + regmap_write(i2c_bus->global_regs,
> AST2600_I2CG_CLK_DIV_CTRL, I2CCG_DIV_CTRL);
> > + }
> > +
> > + i2c_bus->slave_operate = 0;
> > + i2c_bus->dev = dev;
> > + i2c_bus->mode = BUFF_MODE;
> > +
> > + if (of_property_read_bool(pdev->dev.of_node, "aspeed,enable-dma"))
> > + i2c_bus->mode = DMA_MODE;
> > +
> > + if (i2c_bus->mode == BUFF_MODE) {
> > + res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> > + if (res && resource_size(res) >= 2) {
> > + i2c_bus->buf_base = devm_ioremap_resource(dev, res);
> > +
> > + if (!IS_ERR_OR_NULL(i2c_bus->buf_base))
> > + i2c_bus->buf_size = resource_size(res)/2;
> > + } else
> > + i2c_bus->mode = BYTE_MODE;
> > + }
> > +
> > + /* i2c timeout counter: use base clk4 1Mhz,
> > + * per unit: 1/(1000/4096) = 4096us
> > + */
> > + ret = of_property_read_u32(dev->of_node,
> > + "i2c-scl-clk-low-timeout-us",
> > + &i2c_bus->timeout);
>
> Strange layout.
Sorry, could you point out the strange? It just property read for timeout.
>
> > + if (ret < 0)
> > + i2c_bus->timeout = 0;
>
> Nit: This is not really needed since i2c_bus is kzalloc()'ed.
Got it, will remove it.
>
> > + else
> > + i2c_bus->timeout /= 4096;
> > +
> > + init_completion(&i2c_bus->cmd_complete);
> > +
> > + i2c_bus->irq = platform_get_irq(pdev, 0);
> > + if (i2c_bus->irq < 0)
> > + return i2c_bus->irq;
> > +
> > + platform_set_drvdata(pdev, i2c_bus);
> > +
> > + i2c_bus->clk = devm_clk_get(i2c_bus->dev, NULL);
> > + if (IS_ERR(i2c_bus->clk))
> > + return dev_err_probe(i2c_bus->dev, PTR_ERR(i2c_bus->clk),
> "Can't get clock\n");
> > +
> > + i2c_bus->apb_clk = clk_get_rate(i2c_bus->clk);
> > +
> > + ret = of_property_read_u32(dev->of_node, "clock-frequency",
> &i2c_bus->bus_frequency);
> > + if (ret < 0) {
> > + dev_warn(dev, "Could not read clock-frequency property\n");
> > + i2c_bus->bus_frequency = 100000;
> > + }
> > +
> > + /* Initialize the I2C adapter */
> > + i2c_bus->adap.owner = THIS_MODULE;
> > + i2c_bus->adap.algo = &i2c_ast2600_algorithm;
> > + i2c_bus->adap.retries = 0;
> > + i2c_bus->adap.dev.parent = i2c_bus->dev;
> > + i2c_bus->adap.dev.of_node = dev->of_node;
> > + i2c_bus->adap.algo_data = i2c_bus;
> > + strscpy(i2c_bus->adap.name, pdev->name,
> sizeof(i2c_bus->adap.name));
> > + i2c_set_adapdata(&i2c_bus->adap, i2c_bus);
> > +
> > + ast2600_i2c_init(i2c_bus);
> > +
> > + ret = devm_request_irq(dev, i2c_bus->irq, ast2600_i2c_bus_irq, 0,
> > + dev_name(dev), i2c_bus);
> > + if (ret < 0)
> > + return dev_err_probe(dev, ret, "Unable to request irq %d\n",
> i2c_bus->irq);
> > +
> > + if (of_property_read_bool(dev->of_node, "smbus-alert")) {
> > + i2c_bus->alert_enable = 1;
> > + i2c_bus->ara = i2c_new_smbus_alert_device(&i2c_bus->adap,
> &i2c_bus->alert_data);
> > + if (!i2c_bus->ara)
> > + dev_warn(dev, "Failed to register ARA client\n");
> > +
> > + writel(AST2600_I2CM_PKT_DONE |
> AST2600_I2CM_BUS_RECOVER |
> AST2600_I2CM_SMBUS_ALT,
> > + i2c_bus->reg_base + AST2600_I2CM_IER);
> > + } else {
> > + i2c_bus->alert_enable = 0;
> > + /* Set interrupt generation of I2C master controller */
> > + writel(AST2600_I2CM_PKT_DONE |
> AST2600_I2CM_BUS_RECOVER,
> > + i2c_bus->reg_base + AST2600_I2CM_IER);
> > + }
> > +
> > + ret = i2c_add_adapter(&i2c_bus->adap);
>
> Maybe devm_i2c_add_adapter() + remove function simplification.
> This change + dmam_alloc_coherent() above + removing devm_free_irq()
> should, all together, not chnage the order of the remove function IIUIC.
>
Got it, will check devm_i2c_add_adapter.
> CJ
>
> > + if (ret)
> > + return ret;
> > +
> > + dev_info(dev, "%s [%d]: adapter [%d khz] mode [%d]\n",
> > + dev->of_node->name, i2c_bus->adap.nr,
> i2c_bus->bus_frequency / 1000,
> > + i2c_bus->mode);
> > +
> > + return 0;
> > +}
> > +
> > +static int ast2600_i2c_remove(struct platform_device *pdev)
> > +{
> > + struct ast2600_i2c_bus *i2c_bus = platform_get_drvdata(pdev);
> > +
> > + /* Disable everything. */
> > + writel(0, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
> > + writel(0, i2c_bus->reg_base + AST2600_I2CM_IER);
> > +
> > + i2c_del_adapter(&i2c_bus->adap);
> > + devm_free_irq(&pdev->dev, i2c_bus->irq, i2c_bus);
> > +
> > +#ifdef CONFIG_I2C_SLAVE
> > + /* for memory buffer initial */
> > + if (i2c_bus->mode == DMA_MODE)
> > + dma_free_coherent(i2c_bus->dev, I2C_SLAVE_MSG_BUF_SIZE,
> > + i2c_bus->slave_dma_buf, i2c_bus->slave_dma_addr);
> > +#endif
> > +
> > + return 0;
> > +}
> > +
> > +static struct platform_driver ast2600_i2c_bus_driver = {
> > + .probe = ast2600_i2c_probe,
> > + .remove = ast2600_i2c_remove,
> > + .driver = {
> > + .name = KBUILD_MODNAME,
> > + .of_match_table = ast2600_i2c_bus_of_table,
> > + },
> > +};
> > +module_platform_driver(ast2600_i2c_bus_driver);
> > +
> > +MODULE_AUTHOR("Ryan Chen <ryan_chen@xxxxxxxxxxxxxx>");
> > +MODULE_DESCRIPTION("ASPEED AST2600 I2C Controller Driver");
> > +MODULE_LICENSE("GPL");
