From 90a50a3b5ff3863c3a3c2fd5959dacaa742b7797 Mon Sep 17 00:00:00 2001

From: Pablo Greco <pablo@fliagreco.com.ar>

Date: Fri, 29 Mar 2019 18:41:35 +0000

Subject: [PATCH] Reintroduce 80d7fcc321f01c7a69de38a20de726fe8e1149ee

---

 drivers/i2c/busses/i2c-bcm2835.c | 100 ++++++++++++++++++++++++++++++++++++++-

 1 file changed, 99 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-bcm2835.c b/drivers/i2c/busses/i2c-bcm2835.c

index 4d19254..31d8d9e 100644

--- a/drivers/i2c/busses/i2c-bcm2835.c

+++ b/drivers/i2c/busses/i2c-bcm2835.c

@@ -56,6 +56,18 @@

 #define BCM2835_I2C_CDIV_MIN	0x0002

 #define BCM2835_I2C_CDIV_MAX	0xFFFE

+static unsigned int debug;

+module_param(debug, uint, 0644);

+MODULE_PARM_DESC(debug, "1=err, 2=isr, 3=xfer");

+

+#define BCM2835_DEBUG_MAX	512

+struct bcm2835_debug {

+	struct i2c_msg *msg;

+	int msg_idx;

+	size_t remain;

+	u32 status;

+};

+

 struct bcm2835_i2c_dev {

 	struct device *dev;

 	void __iomem *regs;

@@ -69,8 +81,78 @@ struct bcm2835_i2c_dev {

 	u32 msg_err;

 	u8 *msg_buf;

 	size_t msg_buf_remaining;

+	struct bcm2835_debug debug[BCM2835_DEBUG_MAX];

+	unsigned int debug_num;

+	unsigned int debug_num_msgs;

 };

+static inline void bcm2835_debug_add(struct bcm2835_i2c_dev *i2c_dev, u32 s)

+{

+	if (!i2c_dev->debug_num_msgs || i2c_dev->debug_num >= BCM2835_DEBUG_MAX)

+		return;

+

+	i2c_dev->debug[i2c_dev->debug_num].msg = i2c_dev->curr_msg;

+	i2c_dev->debug[i2c_dev->debug_num].msg_idx =

+				i2c_dev->debug_num_msgs - i2c_dev->num_msgs;

+	i2c_dev->debug[i2c_dev->debug_num].remain = i2c_dev->msg_buf_remaining;

+	i2c_dev->debug[i2c_dev->debug_num].status = s;

+	i2c_dev->debug_num++;

+}

+

+static void bcm2835_debug_print_status(struct bcm2835_i2c_dev *i2c_dev,

+				       struct bcm2835_debug *d)

+{

+	u32 s = d->status;

+

+	pr_info("isr: remain=%zu, status=0x%x : %s%s%s%s%s%s%s%s%s%s [i2c%d]\n",

+		d->remain, s,

+		s & BCM2835_I2C_S_TA ? "TA " : "",

+		s & BCM2835_I2C_S_DONE ? "DONE " : "",

+		s & BCM2835_I2C_S_TXW ? "TXW " : "",

+		s & BCM2835_I2C_S_RXR ? "RXR " : "",

+		s & BCM2835_I2C_S_TXD ? "TXD " : "",

+		s & BCM2835_I2C_S_RXD ? "RXD " : "",

+		s & BCM2835_I2C_S_TXE ? "TXE " : "",

+		s & BCM2835_I2C_S_RXF ? "RXF " : "",

+		s & BCM2835_I2C_S_ERR ? "ERR " : "",

+		s & BCM2835_I2C_S_CLKT ? "CLKT " : "",

+		i2c_dev->adapter.nr);

+}

+

+static void bcm2835_debug_print_msg(struct bcm2835_i2c_dev *i2c_dev,

+				    struct i2c_msg *msg, int i, int total,

+				    const char *fname)

+{

+	pr_info("%s: msg(%d/%d) %s addr=0x%02x, len=%u flags=%s%s%s%s%s%s%s [i2c%d]\n",

+		fname, i, total,

+		msg->flags & I2C_M_RD ? "read" : "write", msg->addr, msg->len,

+		msg->flags & I2C_M_TEN ? "TEN" : "",

+		msg->flags & I2C_M_RECV_LEN ? "RECV_LEN" : "",

+		msg->flags & I2C_M_NO_RD_ACK ? "NO_RD_ACK" : "",

+		msg->flags & I2C_M_IGNORE_NAK ? "IGNORE_NAK" : "",

+		msg->flags & I2C_M_REV_DIR_ADDR ? "REV_DIR_ADDR" : "",

+		msg->flags & I2C_M_NOSTART ? "NOSTART" : "",

+		msg->flags & I2C_M_STOP ? "STOP" : "",

+		i2c_dev->adapter.nr);

+}

+

+static void bcm2835_debug_print(struct bcm2835_i2c_dev *i2c_dev)

+{

+	struct bcm2835_debug *d;

+	unsigned int i;

+

+	for (i = 0; i < i2c_dev->debug_num; i++) {

+		d = &i2c_dev->debug[i];

+		if (d->status == ~0)

+			bcm2835_debug_print_msg(i2c_dev, d->msg, d->msg_idx,

+				i2c_dev->debug_num_msgs, "start_transfer");

+		else

+			bcm2835_debug_print_status(i2c_dev, d);

+	}

+	if (i2c_dev->debug_num >= BCM2835_DEBUG_MAX)

+		pr_info("BCM2835_DEBUG_MAX reached\n");

+}

+

 static inline void bcm2835_i2c_writel(struct bcm2835_i2c_dev *i2c_dev,

 				      u32 reg, u32 val)

 {

@@ -189,6 +271,7 @@ static void bcm2835_i2c_start_transfer(struct bcm2835_i2c_dev *i2c_dev)

 	bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_A, msg->addr);

 	bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_DLEN, msg->len);

 	bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_C, c);

+	bcm2835_debug_add(i2c_dev, ~0);

 }

 static void bcm2835_i2c_finish_transfer(struct bcm2835_i2c_dev *i2c_dev)

@@ -215,6 +298,7 @@ static irqreturn_t bcm2835_i2c_isr(int this_irq, void *data)

 	u32 val, err;

 	val = bcm2835_i2c_readl(i2c_dev, BCM2835_I2C_S);

+	bcm2835_debug_add(i2c_dev, val);

 	err = val & (BCM2835_I2C_S_CLKT | BCM2835_I2C_S_ERR);

 	if (err) {

@@ -281,6 +365,13 @@ static int bcm2835_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],

 	unsigned long time_left;

 	int i, ret;

+	if (debug)

+		i2c_dev->debug_num_msgs = num;

+

+	if (debug > 2)

+		for (i = 0; i < num; i++)

+			bcm2835_debug_print_msg(i2c_dev, &msgs[i], i + 1, num, __func__);

+

 	for (i = 0; i < (num - 1); i++)

 		if (msgs[i].flags & I2C_M_RD) {

 			dev_warn_once(i2c_dev->dev,

@@ -303,6 +394,11 @@ static int bcm2835_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],

 	bcm2835_i2c_finish_transfer(i2c_dev);

+	if (debug > 1 || (debug && (!time_left || i2c_dev->msg_err)))

+		bcm2835_debug_print(i2c_dev);

+	i2c_dev->debug_num_msgs = 0;

+	i2c_dev->debug_num = 0;

+

 	if (!time_left) {

 		bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_C,

 				   BCM2835_I2C_C_CLEAR);

@@ -313,7 +409,9 @@ static int bcm2835_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],

 	if (!i2c_dev->msg_err)

 		return num;

-	dev_dbg(i2c_dev->dev, "i2c transfer failed: %x\n", i2c_dev->msg_err);

+	if (debug)

+		dev_err(i2c_dev->dev, "i2c transfer failed: %x\n",

+			i2c_dev->msg_err);

 	if (i2c_dev->msg_err & BCM2835_I2C_S_ERR)

 		return -EREMOTEIO;

-- 

1.8.3.1