openwrt/target/linux/bcm27xx/patches-4.19/950-0028-i2c-bcm2835-Add-debug-support.patch
Adrian Schmutzler 7d7aa2fd92 brcm2708: rename target to bcm27xx
This change makes the names of Broadcom targets consistent by using
the common notation based on SoC/CPU ID (which is used internally
anyway), bcmXXXX instead of brcmXXXX.
This is even used for target TITLE in make menuconfig already,
only the short target name used brcm so far.

Despite, since subtargets range from bcm2708 to bcm2711, it seems
appropriate to use bcm27xx instead of bcm2708 (again, as already done
for BOARDNAME).

This also renames the packages brcm2708-userland and brcm2708-gpu-fw.

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
Acked-by: Álvaro Fernández Rojas <noltari@gmail.com>
2020-02-14 14:10:51 +01:00

190 lines
6.2 KiB
Diff

From b6494e2070983020d56f82d9d0be74d11b001823 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;
@@ -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(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)
@@ -215,6 +298,7 @@ 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) {
@@ -281,6 +365,13 @@ static int bcm2835_i2c_xfer(struct i2c_a
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 +394,10 @@ 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);
@@ -313,7 +408,9 @@ 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;