[PATCH V5] drivers: i2c: tegra: fix warning/check/error

Bitan Biswas
2019-06-07T05:25:03Z

Fix checkpatch.pl warning(s)/error(s)/check(s) in i2c-tegra.c

Ignore checkpatch WARNING for 80 character line limit at
places where renaming fields compromises readability.

Delay of approximately 1msec in flush i2c FIFO polling loop
achieved by usleep_range call as msleep can take 20msecs.

Remove redundant BUG_ON calls or replace with WARN_ON_ONCE
as needed. Replace BUG() with error handling code.
Define I2C_ERR_UNEXPECTED_STATUS for error handling.

Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
---
drivers/i2c/busses/i2c-tegra.c | 61 ++++++++++++++++++++++--------------------
1 file changed, 32 insertions(+), 29 deletions(-)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 1dbba39..161eb28 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -67,17 +67,18 @@

#define DVC_CTRL_REG1 0x000
#define DVC_CTRL_REG1_INTR_EN BIT(10)
-#define DVC_CTRL_REG2 0x004
-#define DVC_CTRL_REG3 0x008
+#define DVC_CTRL_REG2 BIT(2)
+#define DVC_CTRL_REG3 BIT(3)
#define DVC_CTRL_REG3_SW_PROG BIT(26)
#define DVC_CTRL_REG3_I2C_DONE_INTR_EN BIT(30)
#define DVC_STATUS 0x00c
#define DVC_STATUS_I2C_DONE_INTR BIT(30)

-#define I2C_ERR_NONE 0x00
-#define I2C_ERR_NO_ACK 0x01
-#define I2C_ERR_ARBITRATION_LOST 0x02
-#define I2C_ERR_UNKNOWN_INTERRUPT 0x04
+#define I2C_ERR_NONE 0x0
+#define I2C_ERR_NO_ACK BIT(0)
+#define I2C_ERR_ARBITRATION_LOST BIT(1)
+#define I2C_ERR_UNKNOWN_INTERRUPT BIT(2)
+#define I2C_ERR_UNEXPECTED_STATUS BIT(3)

#define PACKET_HEADER0_HEADER_SIZE_SHIFT 28
#define PACKET_HEADER0_PACKET_ID_SHIFT 16
@@ -280,6 +281,7 @@ struct tegra_i2c_dev {
u32 bus_clk_rate;
u16 clk_divisor_non_hs_mode;
bool is_multimaster_mode;
+ /* xfer_lock: lock to serialize transfer submission and processing */
spinlock_t xfer_lock;
struct dma_chan *tx_dma_chan;
struct dma_chan *rx_dma_chan;
@@ -306,7 +308,7 @@ static u32 dvc_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg)
* to the I2C block inside the DVC block
*/
static unsigned long tegra_i2c_reg_addr(struct tegra_i2c_dev *i2c_dev,
- unsigned long reg)
+ unsigned long reg)
{
if (i2c_dev->is_dvc)
reg += (reg >= I2C_TX_FIFO) ? 0x10 : 0x40;
@@ -314,7 +316,7 @@ static unsigned long tegra_i2c_reg_addr(struct tegra_i2c_dev *i2c_dev,
}

static void i2c_writel(struct tegra_i2c_dev *i2c_dev, u32 val,
- unsigned long reg)
+ unsigned long reg)
{
writel(val, i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));

@@ -329,13 +331,13 @@ static u32 i2c_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg)
}

static void i2c_writesl(struct tegra_i2c_dev *i2c_dev, void *data,
- unsigned long reg, int len)
+ unsigned long reg, int len)
{
writesl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
}

static void i2c_readsl(struct tegra_i2c_dev *i2c_dev, void *data,
- unsigned long reg, int len)
+ unsigned long reg, int len)
{
readsl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
}
@@ -486,7 +488,7 @@ static int tegra_i2c_flush_fifos(struct tegra_i2c_dev *i2c_dev)
dev_warn(i2c_dev->dev, "timeout waiting for fifo flush\n");
return -ETIMEDOUT;
}
- msleep(1);
+ usleep_range(1000, 2000);
}
return 0;
}
@@ -525,7 +527,6 @@ static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
* prevent overwriting past the end of buf
*/
if (rx_fifo_avail > 0 && buf_remaining > 0) {
- BUG_ON(buf_remaining > 3);
val = i2c_readl(i2c_dev, I2C_RX_FIFO);
val = cpu_to_le32(val);
memcpy(buf, &val, buf_remaining);
@@ -533,7 +534,6 @@ static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
rx_fifo_avail--;
}

- BUG_ON(rx_fifo_avail > 0 && buf_remaining > 0);
i2c_dev->msg_buf_remaining = buf_remaining;
i2c_dev->msg_buf = buf;

@@ -591,7 +591,6 @@ static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev)
* boundary and fault.
*/
if (tx_fifo_avail > 0 && buf_remaining > 0) {
- BUG_ON(buf_remaining > 3);
memcpy(&val, buf, buf_remaining);
val = le32_to_cpu(val);

@@ -680,10 +679,11 @@ static int tegra_i2c_wait_for_config_load(struct tegra_i2c_dev *i2c_dev)
i2c_writel(i2c_dev, I2C_MSTR_CONFIG_LOAD, I2C_CONFIG_LOAD);
if (in_interrupt())
err = readl_poll_timeout_atomic(addr, val, val == 0,
- 1000, I2C_CONFIG_LOAD_TIMEOUT);
+ 1000,
+ I2C_CONFIG_LOAD_TIMEOUT);
else
- err = readl_poll_timeout(addr, val, val == 0,
- 1000, I2C_CONFIG_LOAD_TIMEOUT);
+ err = readl_poll_timeout(addr, val, val == 0, 1000,
+ I2C_CONFIG_LOAD_TIMEOUT);

if (err) {
dev_warn(i2c_dev->dev,
@@ -856,10 +856,13 @@ static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)

if (!i2c_dev->is_curr_dma_xfer) {
if (i2c_dev->msg_read && (status & I2C_INT_RX_FIFO_DATA_REQ)) {
- if (i2c_dev->msg_buf_remaining)
+ if (i2c_dev->msg_buf_remaining) {
tegra_i2c_empty_rx_fifo(i2c_dev);
- else
- BUG();
+ } else {
+ dev_err(i2c_dev->dev, "unexpected rx data request\n");
+ i2c_dev->msg_err |= I2C_ERR_UNEXPECTED_STATUS;
+ goto err;
+ }
}

if (!i2c_dev->msg_read && (status & I2C_INT_TX_FIFO_DATA_REQ)) {
@@ -885,7 +888,7 @@ static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
if (status & I2C_INT_PACKET_XFER_COMPLETE) {
if (i2c_dev->is_curr_dma_xfer)
i2c_dev->msg_buf_remaining = 0;
- BUG_ON(i2c_dev->msg_buf_remaining);
+ WARN_ON_ONCE(i2c_dev->msg_buf_remaining);
complete(&i2c_dev->msg_complete);
}
goto done;
@@ -1024,7 +1027,7 @@ static int tegra_i2c_issue_bus_clear(struct i2c_adapter *adap)
}

static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
- struct i2c_msg *msg, enum msg_end_type end_state)
+ struct i2c_msg *msg, enum msg_end_type end_state)
{
u32 packet_header;
u32 int_mask;
@@ -1161,9 +1164,8 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
if (err)
return err;

- time_left = wait_for_completion_timeout(
- &i2c_dev->dma_complete,
- msecs_to_jiffies(xfer_time));
+ time_left = wait_for_completion_timeout(&i2c_dev->dma_complete,
+ msecs_to_jiffies(xfer_time));
if (time_left == 0) {
dev_err(i2c_dev->dev, "DMA transfer timeout\n");
dmaengine_terminate_sync(i2c_dev->msg_read ?
@@ -1225,7 +1227,7 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
}

static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
- int num)
+ int num)
{
struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
int i;
@@ -1273,12 +1275,12 @@ static void tegra_i2c_parse_dt(struct tegra_i2c_dev *i2c_dev)
int ret;

ret = of_property_read_u32(np, "clock-frequency",
- &i2c_dev->bus_clk_rate);
+ &i2c_dev->bus_clk_rate);
if (ret)
i2c_dev->bus_clk_rate = 100000; /* default clock rate */

i2c_dev->is_multimaster_mode = of_property_read_bool(np,
- "multi-master");
+ "multi-master");
}

static const struct i2c_algorithm tegra_i2c_algo = {
@@ -1622,7 +1624,7 @@ static int tegra_i2c_probe(struct platform_device *pdev)
}

ret = devm_request_irq(&pdev->dev, i2c_dev->irq,
- tegra_i2c_isr, 0, dev_name(&pdev->dev), i2c_dev);
+ tegra_i2c_isr, 0, dev_name(&pdev->dev), i2c_dev);
if (ret) {
dev_err(&pdev->dev, "Failed to request irq %i\n", i2c_dev->irq);
goto release_dma;
@@ -1715,6 +1717,7 @@ static const struct dev_pm_ops tegra_i2c_pm = {
SET_RUNTIME_PM_OPS(tegra_i2c_runtime_suspend, tegra_i2c_runtime_resume,
NULL)
};
+
#define TEGRA_I2C_PM (&tegra_i2c_pm)
#else
#define TEGRA_I2C_PM NULL
--
2.7.4