i2c: cadence: Add standard bus recovery support

Message ID 20210415232532.4070366-1-robert.hancock@calian.com
State New
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Series
  • i2c: cadence: Add standard bus recovery support
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Commit Message

Robert Hancock April 15, 2021, 11:25 p.m.
Hook up the standard GPIO/pinctrl-based recovery support for this
driver.

Based on a patch "i2c: cadence: Recover bus after controller reset" by
Chirag Parekh in the Xilinx kernel Git tree, but simplified to make use
of more common code.

Cc: Chirag Parekh <chiragp@xilinx.com>
Signed-off-by: Robert Hancock <robert.hancock@calian.com>
---
 drivers/i2c/busses/i2c-cadence.c | 4 ++++
 1 file changed, 4 insertions(+)

Comments

Michal Simek April 20, 2021, 1:23 p.m. | #1
Hi,

On 4/16/21 1:25 AM, Robert Hancock wrote:
> Hook up the standard GPIO/pinctrl-based recovery support for this

> driver.

> 

> Based on a patch "i2c: cadence: Recover bus after controller reset" by

> Chirag Parekh in the Xilinx kernel Git tree, but simplified to make use

> of more common code.

> 

> Cc: Chirag Parekh <chiragp@xilinx.com>

> Signed-off-by: Robert Hancock <robert.hancock@calian.com>

> ---

>  drivers/i2c/busses/i2c-cadence.c | 4 ++++

>  1 file changed, 4 insertions(+)

> 

> diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-cadence.c

> index c1bbc4caeb5c..d017bc64e759 100644

> --- a/drivers/i2c/busses/i2c-cadence.c

> +++ b/drivers/i2c/busses/i2c-cadence.c

> @@ -178,6 +178,7 @@ enum cdns_i2c_slave_state {

>   * @clk:		Pointer to struct clk

>   * @clk_rate_change_nb:	Notifier block for clock rate changes

>   * @quirks:		flag for broken hold bit usage in r1p10

> + * @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).

> @@ -202,6 +203,7 @@ struct cdns_i2c {

>  	struct clk *clk;

>  	struct notifier_block clk_rate_change_nb;

>  	u32 quirks;

> +	struct i2c_bus_recovery_info rinfo;

>  #if IS_ENABLED(CONFIG_I2C_SLAVE)

>  	u16 ctrl_reg_diva_divb;

>  	struct i2c_client *slave;

> @@ -752,6 +754,7 @@ 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, adap->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");

> @@ -1212,6 +1215,7 @@ 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);

> 


My colleague sent pinctrl driver for ZynqMP already. This driver can be
used on Zynq where pinctrl driver already exists upstream.

It looks quite nice.

Acked-by: Michal Simek <michal.simek@xilinx.com>


Thanks,
Michal
Robert Hancock June 30, 2021, 4:40 p.m. | #2
On Tue, 2021-04-20 at 15:23 +0200, Michal Simek wrote:
> Hi,

> 

> On 4/16/21 1:25 AM, Robert Hancock wrote:

> > Hook up the standard GPIO/pinctrl-based recovery support for this

> > driver.

> > 

> > Based on a patch "i2c: cadence: Recover bus after controller reset" by

> > Chirag Parekh in the Xilinx kernel Git tree, but simplified to make use

> > of more common code.

> > 

> > Cc: Chirag Parekh <chiragp@xilinx.com>

> > Signed-off-by: Robert Hancock <robert.hancock@calian.com>

> > ---

> >  drivers/i2c/busses/i2c-cadence.c | 4 ++++

> >  1 file changed, 4 insertions(+)

> > 

> > diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-

> > cadence.c

> > index c1bbc4caeb5c..d017bc64e759 100644

> > --- a/drivers/i2c/busses/i2c-cadence.c

> > +++ b/drivers/i2c/busses/i2c-cadence.c

> > @@ -178,6 +178,7 @@ enum cdns_i2c_slave_state {

> >   * @clk:		Pointer to struct clk

> >   * @clk_rate_change_nb:	Notifier block for clock rate changes

> >   * @quirks:		flag for broken hold bit usage in r1p10

> > + * @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).

> > @@ -202,6 +203,7 @@ struct cdns_i2c {

> >  	struct clk *clk;

> >  	struct notifier_block clk_rate_change_nb;

> >  	u32 quirks;

> > +	struct i2c_bus_recovery_info rinfo;

> >  #if IS_ENABLED(CONFIG_I2C_SLAVE)

> >  	u16 ctrl_reg_diva_divb;

> >  	struct i2c_client *slave;

> > @@ -752,6 +754,7 @@ 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, adap->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");

> > @@ -1212,6 +1215,7 @@ 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);

> > 

> 

> My colleague sent pinctrl driver for ZynqMP already. This driver can be

> used on Zynq where pinctrl driver already exists upstream.

> 

> It looks quite nice.

> 

> Acked-by: Michal Simek <michal.simek@xilinx.com>

> 


Any other feedback on this patch? I only saw the ack from Michal. The pinctrl
driver which is needed to make this useful on the ZynqMP platform has now been
merged into mainline (commit 8b242ca700f8043be56542efd8360056358a42ed,
"pinctrl: Add Xilinx ZynqMP pinctrl driver support").

> Thanks,

> Michal

-- 
Robert Hancock
Senior Hardware Designer, Calian Advanced Technologies
www.calian.com

Patch

diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-cadence.c
index c1bbc4caeb5c..d017bc64e759 100644
--- a/drivers/i2c/busses/i2c-cadence.c
+++ b/drivers/i2c/busses/i2c-cadence.c
@@ -178,6 +178,7 @@  enum cdns_i2c_slave_state {
  * @clk:		Pointer to struct clk
  * @clk_rate_change_nb:	Notifier block for clock rate changes
  * @quirks:		flag for broken hold bit usage in r1p10
+ * @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).
@@ -202,6 +203,7 @@  struct cdns_i2c {
 	struct clk *clk;
 	struct notifier_block clk_rate_change_nb;
 	u32 quirks;
+	struct i2c_bus_recovery_info rinfo;
 #if IS_ENABLED(CONFIG_I2C_SLAVE)
 	u16 ctrl_reg_diva_divb;
 	struct i2c_client *slave;
@@ -752,6 +754,7 @@  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, adap->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");
@@ -1212,6 +1215,7 @@  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);