On 7/4/22 07:54, Shubhrajyoti Datta wrote:
From: Robert Hancock <robert.hancock@xxxxxxxxxx>
Hook up the standard GPIO/pinctrl-based recovery support..
In the discurssion
typo
https://patchwork.ozlabs.org/project/linux-i2c/patch/20211129090116.16628-1-shubhrajyoti.datta@xxxxxxxxxx/
recovery should be done at the beginning of the transaction.
Here we are doing the recovery at the beginning on a timeout.
Signed-off-by: Robert Hancock <robert.hancock@xxxxxxxxxx>
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxx>
---
v2:
Updated the busbusy check on a timeout
drivers/i2c/busses/i2c-cadence.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-cadence.c
index b4c1ad19cdae..cf15eca1f9e4 100644
--- a/drivers/i2c/busses/i2c-cadence.c
+++ b/drivers/i2c/busses/i2c-cadence.c
@@ -10,6 +10,7 @@
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/io.h>
+#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/of.h>
@@ -125,6 +126,8 @@
#define CDNS_I2C_DIVB_MAX 64
#define CDNS_I2C_TIMEOUT_MAX 0xFF
+#define CDNS_I2C_POLL_US 100000
+#define CDNS_I2C_TIMEOUT_US 500000
#define CDNS_I2C_BROKEN_HOLD_BIT BIT(0)
@@ -179,6 +182,7 @@ enum cdns_i2c_slave_state {
* @clk_rate_change_nb: Notifier block for clock rate changes
* @quirks: flag for broken hold bit usage in r1p10
* @ctrl_reg: Cached value of the control register.
+ * @rinfo: Structure holding recovery information.
* @ctrl_reg_diva_divb: value of fields DIV_A and DIV_B from CR register
* @slave: Registered slave instance.
* @dev_mode: I2C operating role(master/slave).
@@ -204,6 +208,7 @@ struct cdns_i2c {
struct notifier_block clk_rate_change_nb;
u32 quirks;
u32 ctrl_reg;
+ struct i2c_bus_recovery_info rinfo;
#if IS_ENABLED(CONFIG_I2C_SLAVE)
u16 ctrl_reg_diva_divb;
struct i2c_client *slave;
@@ -796,6 +801,7 @@ static int cdns_i2c_process_msg(struct cdns_i2c *id, struct i2c_msg *msg,
/* Wait for the signal of completion */
time_left = wait_for_completion_timeout(&id->xfer_done, msg_timeout);
if (time_left == 0) {
+ i2c_recover_bus(adap);
cdns_i2c_master_reset(adap);
dev_err(id->adap.dev.parent,
"timeout waiting on completion\n");
@@ -852,8 +858,12 @@ static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
#endif
/* Check if the bus is free */
- if (cdns_i2c_readreg(CDNS_I2C_SR_OFFSET) & CDNS_I2C_SR_BA) {
+ ret = readl_poll_timeout(id->membase + CDNS_I2C_SR_OFFSET, reg,
+ !(reg & CDNS_I2C_SR_BA),
+ CDNS_I2C_POLL_US, CDNS_I2C_TIMEOUT_US);
+ if (ret) {
ret = -EAGAIN;
+ i2c_recover_bus(adap);
goto out;
}
@@ -1278,6 +1288,7 @@ static int cdns_i2c_probe(struct platform_device *pdev)
id->adap.retries = 3; /* Default retry value. */
id->adap.algo_data = id;
id->adap.dev.parent = &pdev->dev;
+ id->adap.bus_recovery_info = &id->rinfo;
init_completion(&id->xfer_done);
snprintf(id->adap.name, sizeof(id->adap.name),
"Cadence I2C at %08lx", (unsigned long)r_mem->start);
I have no problem with it. I expect you have tested it on the real HW.
Acked-by: Michal Simek <michal.simek@xxxxxxx>
Thanks,
Michal
