i2c: tegra: support for I2C_M_NOSTART functionality
Adding support for functionality I2C_M_NOSTART. When multiple message transfer request made through i2c and if any message is flagged with I2C_M_NOSTART then it will not send the start/repeat-start and address of that message i.e. sends data directly. Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
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@ -97,8 +97,21 @@
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#define I2C_HEADER_10BIT_ADDR (1<<18)
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#define I2C_HEADER_10BIT_ADDR (1<<18)
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#define I2C_HEADER_IE_ENABLE (1<<17)
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#define I2C_HEADER_IE_ENABLE (1<<17)
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#define I2C_HEADER_REPEAT_START (1<<16)
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#define I2C_HEADER_REPEAT_START (1<<16)
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#define I2C_HEADER_CONTINUE_XFER (1<<15)
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#define I2C_HEADER_MASTER_ADDR_SHIFT 12
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#define I2C_HEADER_MASTER_ADDR_SHIFT 12
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#define I2C_HEADER_SLAVE_ADDR_SHIFT 1
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#define I2C_HEADER_SLAVE_ADDR_SHIFT 1
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/*
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* msg_end_type: The bus control which need to be send at end of transfer.
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* @MSG_END_STOP: Send stop pulse at end of transfer.
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* @MSG_END_REPEAT_START: Send repeat start at end of transfer.
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* @MSG_END_CONTINUE: The following on message is coming and so do not send
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* stop or repeat start.
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*/
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enum msg_end_type {
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MSG_END_STOP,
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MSG_END_REPEAT_START,
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MSG_END_CONTINUE,
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};
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/**
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/**
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* struct tegra_i2c_dev - per device i2c context
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* struct tegra_i2c_dev - per device i2c context
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@ -453,7 +466,7 @@ err:
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}
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}
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static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
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static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
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struct i2c_msg *msg, int stop)
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struct i2c_msg *msg, enum msg_end_type end_state)
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{
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{
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u32 packet_header;
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u32 packet_header;
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u32 int_mask;
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u32 int_mask;
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@ -480,7 +493,9 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
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i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
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i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
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packet_header = I2C_HEADER_IE_ENABLE;
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packet_header = I2C_HEADER_IE_ENABLE;
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if (!stop)
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if (end_state == MSG_END_CONTINUE)
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packet_header |= I2C_HEADER_CONTINUE_XFER;
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else if (end_state == MSG_END_REPEAT_START)
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packet_header |= I2C_HEADER_REPEAT_START;
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packet_header |= I2C_HEADER_REPEAT_START;
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if (msg->flags & I2C_M_TEN) {
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if (msg->flags & I2C_M_TEN) {
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packet_header |= msg->addr;
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packet_header |= msg->addr;
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@ -552,8 +567,14 @@ static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
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clk_enable(i2c_dev->clk);
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clk_enable(i2c_dev->clk);
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for (i = 0; i < num; i++) {
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for (i = 0; i < num; i++) {
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int stop = (i == (num - 1)) ? 1 : 0;
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enum msg_end_type end_type = MSG_END_STOP;
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ret = tegra_i2c_xfer_msg(i2c_dev, &msgs[i], stop);
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if (i < (num - 1)) {
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if (msgs[i + 1].flags & I2C_M_NOSTART)
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end_type = MSG_END_CONTINUE;
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else
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end_type = MSG_END_REPEAT_START;
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}
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ret = tegra_i2c_xfer_msg(i2c_dev, &msgs[i], end_type);
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if (ret)
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if (ret)
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break;
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break;
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}
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}
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@ -564,7 +585,7 @@ static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
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static u32 tegra_i2c_func(struct i2c_adapter *adap)
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static u32 tegra_i2c_func(struct i2c_adapter *adap)
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{
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{
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return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR |
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return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR |
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I2C_FUNC_PROTOCOL_MANGLING;
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I2C_FUNC_PROTOCOL_MANGLING | I2C_FUNC_NOSTART;
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}
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}
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static const struct i2c_algorithm tegra_i2c_algo = {
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static const struct i2c_algorithm tegra_i2c_algo = {
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