From 4be62340f3ce62b90a01ce11a6bc2426606614c5 Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Wed, 30 Sep 2020 01:19:06 +0300 Subject: [PATCH] i2c: tegra: Factor out packet header setup from tegra_i2c_xfer_msg() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The code related to packet header setting up is a bit messy and makes tegra_i2c_xfer_msg() more difficult to read than it could be. Let's factor the packet header setup from tegra_i2c_xfer_msg() into separate function in order to make code easier to read and follow. Reviewed-by: Michał Mirosław Reviewed-by: Andy Shevchenko Acked-by: Thierry Reding Tested-by: Thierry Reding Signed-off-by: Dmitry Osipenko Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-tegra.c | 95 ++++++++++++++++++++-------------- 1 file changed, 55 insertions(+), 40 deletions(-) diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c index 95d257cbd800..fbeae872ece1 100644 --- a/drivers/i2c/busses/i2c-tegra.c +++ b/drivers/i2c/busses/i2c-tegra.c @@ -281,7 +281,7 @@ struct tegra_i2c_dev { struct dma_chan *tx_dma_chan; struct dma_chan *rx_dma_chan; dma_addr_t dma_phys; - u32 *dma_buf; + void *dma_buf; unsigned int dma_buf_size; bool is_curr_dma_xfer; struct completion dma_complete; @@ -1105,6 +1105,57 @@ static int tegra_i2c_issue_bus_clear(struct i2c_adapter *adap) return -EAGAIN; } +static void tegra_i2c_push_packet_header(struct tegra_i2c_dev *i2c_dev, + struct i2c_msg *msg, + enum msg_end_type end_state) +{ + u32 *dma_buf = i2c_dev->dma_buf; + u32 packet_header; + + packet_header = FIELD_PREP(PACKET_HEADER0_HEADER_SIZE, 0) | + FIELD_PREP(PACKET_HEADER0_PROTOCOL, + PACKET_HEADER0_PROTOCOL_I2C) | + FIELD_PREP(PACKET_HEADER0_CONT_ID, i2c_dev->cont_id) | + FIELD_PREP(PACKET_HEADER0_PACKET_ID, 1); + + if (i2c_dev->is_curr_dma_xfer && !i2c_dev->msg_read) + *dma_buf++ = packet_header; + else + i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO); + + packet_header = msg->len - 1; + + if (i2c_dev->is_curr_dma_xfer && !i2c_dev->msg_read) + *dma_buf++ = packet_header; + else + i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO); + + packet_header = I2C_HEADER_IE_ENABLE; + + if (end_state == MSG_END_CONTINUE) + packet_header |= I2C_HEADER_CONTINUE_XFER; + else if (end_state == MSG_END_REPEAT_START) + packet_header |= I2C_HEADER_REPEAT_START; + + if (msg->flags & I2C_M_TEN) { + packet_header |= msg->addr; + packet_header |= I2C_HEADER_10BIT_ADDR; + } else { + packet_header |= msg->addr << I2C_HEADER_SLAVE_ADDR_SHIFT; + } + + if (msg->flags & I2C_M_IGNORE_NAK) + packet_header |= I2C_HEADER_CONT_ON_NAK; + + if (msg->flags & I2C_M_RD) + packet_header |= I2C_HEADER_READ; + + if (i2c_dev->is_curr_dma_xfer && !i2c_dev->msg_read) + *dma_buf++ = packet_header; + else + i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO); +} + static int tegra_i2c_error_recover(struct tegra_i2c_dev *i2c_dev, struct i2c_msg *msg) { @@ -1135,11 +1186,9 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev, struct i2c_msg *msg, enum msg_end_type end_state) { - u32 packet_header; u32 int_mask; unsigned long time_left; size_t xfer_size; - u32 *buffer = NULL; int err = 0; u16 xfer_time = 100; @@ -1192,49 +1241,15 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev, i2c_dev->dma_phys, xfer_size, DMA_TO_DEVICE); - buffer = i2c_dev->dma_buf; } } - packet_header = FIELD_PREP(PACKET_HEADER0_HEADER_SIZE, 0) | - FIELD_PREP(PACKET_HEADER0_PROTOCOL, - PACKET_HEADER0_PROTOCOL_I2C) | - FIELD_PREP(PACKET_HEADER0_CONT_ID, i2c_dev->cont_id) | - FIELD_PREP(PACKET_HEADER0_PACKET_ID, 1); - if (i2c_dev->is_curr_dma_xfer && !i2c_dev->msg_read) - *buffer++ = packet_header; - else - i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO); - - packet_header = msg->len - 1; - if (i2c_dev->is_curr_dma_xfer && !i2c_dev->msg_read) - *buffer++ = packet_header; - else - i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO); - - packet_header = I2C_HEADER_IE_ENABLE; - if (end_state == MSG_END_CONTINUE) - packet_header |= I2C_HEADER_CONTINUE_XFER; - else if (end_state == MSG_END_REPEAT_START) - packet_header |= I2C_HEADER_REPEAT_START; - if (msg->flags & I2C_M_TEN) { - packet_header |= msg->addr; - packet_header |= I2C_HEADER_10BIT_ADDR; - } else { - packet_header |= msg->addr << I2C_HEADER_SLAVE_ADDR_SHIFT; - } - if (msg->flags & I2C_M_IGNORE_NAK) - packet_header |= I2C_HEADER_CONT_ON_NAK; - if (msg->flags & I2C_M_RD) - packet_header |= I2C_HEADER_READ; - if (i2c_dev->is_curr_dma_xfer && !i2c_dev->msg_read) - *buffer++ = packet_header; - else - i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO); + tegra_i2c_push_packet_header(i2c_dev, msg, end_state); if (!i2c_dev->msg_read) { if (i2c_dev->is_curr_dma_xfer) { - memcpy(buffer, msg->buf, msg->len); + memcpy(i2c_dev->dma_buf + I2C_PACKET_HEADER_SIZE, + msg->buf, msg->len); dma_sync_single_for_device(i2c_dev->dev, i2c_dev->dma_phys, xfer_size, -- 2.39.5