bcm27xx: add support for linux v5.15

Build system: x86_64
Build-tested: bcm2708, bcm2709, bcm2710, bcm2711
Run-tested: bcm2708/RPiB+, bcm2709/RPi3B, bcm2710/RPi3B, bcm2711/RPi4B

Signed-off-by: Marty Jones <mj8263788@gmail.com>
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>

1 files changed, 189 insertions, 0 deletions

diff --git a/target/linux/bcm27xx/patches-5.15/950-0053-i2c-bcm2835-Add-debug-support.patch b/target/linux/bcm27xx/patches-5.15/950-0053-i2c-bcm2835-Add-debug-support.patch
new file mode 100644
index 0000000000..bcd1ea035f
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.15/950-0053-i2c-bcm2835-Add-debug-support.patch
@@ -0,0 +1,189 @@
+From 2266ce21e9418e110b747deae420fbd08c9c6bb5 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Noralf=20Tr=C3=B8nnes?= <noralf@tronnes.org>
+Date: Tue, 1 Nov 2016 15:15:41 +0100
+Subject: [PATCH] i2c: bcm2835: Add debug support
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+This adds a debug module parameter to aid in debugging transfer issues
+by printing info to the kernel log. When enabled, status values are
+collected in the interrupt routine and msg info in
+bcm2835_i2c_start_transfer(). This is done in a way that tries to avoid
+affecting timing. Having printk in the isr can mask issues.
+
+debug values (additive):
+1: Print info on error
+2: Print info on all transfers
+3: Print messages before transfer is started
+
+The value can be changed at runtime:
+/sys/module/i2c_bcm2835/parameters/debug
+
+Example output, debug=3:
+[  747.114448] bcm2835_i2c_xfer: msg(1/2) write addr=0x54, len=2 flags= [i2c1]
+[  747.114463] bcm2835_i2c_xfer: msg(2/2) read addr=0x54, len=32 flags= [i2c1]
+[  747.117809] start_transfer: msg(1/2) write addr=0x54, len=2 flags= [i2c1]
+[  747.117825] isr: remain=2, status=0x30000055 : TA TXW TXD TXE  [i2c1]
+[  747.117839] start_transfer: msg(2/2) read addr=0x54, len=32 flags= [i2c1]
+[  747.117849] isr: remain=32, status=0xd0000039 : TA RXR TXD RXD  [i2c1]
+[  747.117861] isr: remain=20, status=0xd0000039 : TA RXR TXD RXD  [i2c1]
+[  747.117870] isr: remain=8, status=0x32 : DONE TXD RXD  [i2c1]
+
+Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
+---
+ drivers/i2c/busses/i2c-bcm2835.c | 99 +++++++++++++++++++++++++++++++-
+ 1 file changed, 98 insertions(+), 1 deletion(-)
+
+--- 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;
+@@ -68,8 +80,78 @@ 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)
+ {
+@@ -257,6 +339,7 @@ static void bcm2835_i2c_start_transfer(s
+ 	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)
+@@ -283,6 +366,7 @@ static irqreturn_t bcm2835_i2c_isr(int t
+ 	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) {
+@@ -349,6 +433,13 @@ static int bcm2835_i2c_xfer(struct i2c_a
+ 	unsigned long time_left;
+ 	int i;
+ 
++	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,
+@@ -367,6 +458,10 @@ static int bcm2835_i2c_xfer(struct i2c_a
+ 
+ 	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);
+@@ -377,7 +472,9 @@ static int bcm2835_i2c_xfer(struct i2c_a
+ 	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;