[net-next,v3 0/2] Enable SFP on ACPI based systems

[net-next,v3 0/2] Enable SFP on ACPI based systems

[Ruslan Babayev]

Changes:
v2: more descriptive commit body
v3: made 'i2c_acpi_find_adapter_by_handle' static inline

Ruslan Babayev (2):
  i2c: acpi: export i2c_acpi_find_adapter_by_handle
  net: phy: sfp: enable i2c-bus detection on ACPI based systems

 drivers/i2c/i2c-core-acpi.c |  3 ++-
 drivers/net/phy/sfp.c       | 33 +++++++++++++++++++++++++--------
 include/linux/i2c.h         |  6 ++++++
 3 files changed, 33 insertions(+), 9 deletions(-)

-- 
2.19.2

[net-next,v3 1/2] i2c: acpi: export i2c_acpi_find_adapter_by_handle

[Ruslan Babayev]

This allows drivers to lookup i2c adapters on ACPI based systems similar to
of_get_i2c_adapter_by_node() with DT based systems.

Signed-off-by: Ruslan Babayev <ruslan@babayev.com>
Cc: xe-linux-external@cisco.com
---
 drivers/i2c/i2c-core-acpi.c | 3 ++-
 include/linux/i2c.h         | 6 ++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c
index 272800692088..964687534754 100644
--- a/drivers/i2c/i2c-core-acpi.c
+++ b/drivers/i2c/i2c-core-acpi.c
@@ -337,7 +337,7 @@ static int i2c_acpi_find_match_device(struct device *dev, void *data)
 	return ACPI_COMPANION(dev) == data;
 }
 
-static struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
+struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
 {
 	struct device *dev;
 
@@ -345,6 +345,7 @@ static struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
 			      i2c_acpi_find_match_adapter);
 	return dev ? i2c_verify_adapter(dev) : NULL;
 }
+EXPORT_SYMBOL_GPL(i2c_acpi_find_adapter_by_handle);
 
 static struct i2c_client *i2c_acpi_find_client_by_adev(struct acpi_device *adev)
 {
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 1308126fc384..9808993f5fd5 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -21,6 +21,7 @@
 #include <linux/rtmutex.h>
 #include <linux/irqdomain.h>		/* for Host Notify IRQ */
 #include <linux/of.h>		/* for struct device_node */
+#include <linux/acpi.h>		/* for acpi_handle */
 #include <linux/swab.h>		/* for swab16 */
 #include <uapi/linux/i2c.h>
 
@@ -981,6 +982,7 @@ bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
 u32 i2c_acpi_find_bus_speed(struct device *dev);
 struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
 				       struct i2c_board_info *info);
+struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle);
 #else
 static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
 					     struct acpi_resource_i2c_serialbus **i2c)
@@ -996,6 +998,10 @@ static inline struct i2c_client *i2c_acpi_new_device(struct device *dev,
 {
 	return NULL;
 }
+static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle h)
+{
+	return NULL;
+}
 #endif /* CONFIG_ACPI */
 
 #endif /* _LINUX_I2C_H */
-- 
2.19.2

[net-next,v3 2/2] net: phy: sfp: enable i2c-bus detection on ACPI based systems

[Ruslan Babayev]

Lookup I2C adapter using the "i2c-bus" device property on ACPI based
systems similar to how it's done with DT.

An example DSD describing an SFP on an ACPI based system:

Device (SFP0)
{
    Name (_HID, "PRP0001")
    Name (_CRS, ResourceTemplate()
    {
        GpioIo(Exclusive, PullDefault, 0, 0, IoRestrictionNone,
               "\\_SB.PCI0.RP01.GPIO", 0, ResourceConsumer)
            { 0, 1, 2, 3, 4 }
    })
    Name (_DSD, Package ()
    {
        ToUUID ("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
        Package () {
            Package () { "compatible", "sff,sfp" },
            Package () { "i2c-bus", \_SB.PCI0.RP01.I2C.MUX.CH0 },
            Package () { "maximum-power-milliwatt", 1000 },
            Package () { "tx-disable-gpios", Package () { ^SFP0, 0, 0, 1} },
            Package () { "reset-gpio",       Package () { ^SFP0, 0, 1, 1} },
            Package () { "mod-def0-gpios",   Package () { ^SFP0, 0, 2, 1} },
            Package () { "tx-fault-gpios",   Package () { ^SFP0, 0, 3, 0} },
            Package () { "los-gpios",        Package () { ^SFP0, 0, 4, 1} },
        },
    })
}

Device (PHY0)
{
    Name (_HID, "PRP0001")
    Name (_DSD, Package ()
    {
        ToUUID ("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
        Package () {
            Package () { "compatible", "ethernet-phy-ieee802.3-c45" },
            Package () { "sfp", \_SB.PCI0.RP01.SFP0 },
            Package () { "managed", "in-band-status" },
            Package () { "phy-mode", "sgmii" },
        },
    })
}

Signed-off-by: Ruslan Babayev <ruslan@babayev.com>
Cc: xe-linux-external@cisco.com
---
 drivers/net/phy/sfp.c | 33 +++++++++++++++++++++++++--------
 1 file changed, 25 insertions(+), 8 deletions(-)

diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c
index d4635c2178d1..7a6c8df8899b 100644
--- a/drivers/net/phy/sfp.c
+++ b/drivers/net/phy/sfp.c
@@ -9,6 +9,7 @@
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/of.h>
+#include <linux/acpi.h>
 #include <linux/phy.h>
 #include <linux/platform_device.h>
 #include <linux/rtnetlink.h>
@@ -1783,6 +1784,7 @@ static int sfp_probe(struct platform_device *pdev)
 {
 	const struct sff_data *sff;
 	struct sfp *sfp;
+	struct i2c_adapter *i2c = NULL;
 	bool poll = false;
 	int irq, err, i;
 
@@ -1801,7 +1803,6 @@ static int sfp_probe(struct platform_device *pdev)
 	if (pdev->dev.of_node) {
 		struct device_node *node = pdev->dev.of_node;
 		const struct of_device_id *id;
-		struct i2c_adapter *i2c;
 		struct device_node *np;
 
 		id = of_match_node(sfp_of_match, node);
@@ -1818,14 +1819,30 @@ static int sfp_probe(struct platform_device *pdev)
 
 		i2c = of_find_i2c_adapter_by_node(np);
 		of_node_put(np);
-		if (!i2c)
-			return -EPROBE_DEFER;
-
-		err = sfp_i2c_configure(sfp, i2c);
-		if (err < 0) {
-			i2c_put_adapter(i2c);
-			return err;
+	} else if (ACPI_COMPANION(&pdev->dev)) {
+		struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
+		struct fwnode_handle *fw = acpi_fwnode_handle(adev);
+		struct fwnode_reference_args args;
+		struct acpi_handle *acpi_handle;
+		int ret;
+
+		ret = acpi_node_get_property_reference(fw, "i2c-bus", 0, &args);
+		if (ACPI_FAILURE(ret) || !is_acpi_device_node(args.fwnode)) {
+			dev_err(&pdev->dev, "missing 'i2c-bus' property\n");
+			return -ENODEV;
 		}
+
+		acpi_handle = ACPI_HANDLE_FWNODE(args.fwnode);
+		i2c = i2c_acpi_find_adapter_by_handle(acpi_handle);
+	}
+
+	if (!i2c)
+		return -EPROBE_DEFER;
+
+	err = sfp_i2c_configure(sfp, i2c);
+	if (err < 0) {
+		i2c_put_adapter(i2c);
+		return err;
 	}
 
 	for (i = 0; i < GPIO_MAX; i++)
-- 
2.19.2

Re: [net-next,v3 1/2] i2c: acpi: export i2c_acpi_find_adapter_by_handle

[Mika Westerberg]

On Mon, May 27, 2019 at 08:22:12PM -0700, Ruslan Babayev wrote:
> This allows drivers to lookup i2c adapters on ACPI based systems similar to
> of_get_i2c_adapter_by_node() with DT based systems.
> 
> Signed-off-by: Ruslan Babayev <ruslan@babayev.com>
> Cc: xe-linux-external@cisco.com
> ---
>  drivers/i2c/i2c-core-acpi.c | 3 ++-
>  include/linux/i2c.h         | 6 ++++++
>  2 files changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c
> index 272800692088..964687534754 100644
> --- a/drivers/i2c/i2c-core-acpi.c
> +++ b/drivers/i2c/i2c-core-acpi.c
> @@ -337,7 +337,7 @@ static int i2c_acpi_find_match_device(struct device *dev, void *data)
>  	return ACPI_COMPANION(dev) == data;
>  }
>  
> -static struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
> +struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
>  {
>  	struct device *dev;
>  
> @@ -345,6 +345,7 @@ static struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
>  			      i2c_acpi_find_match_adapter);
>  	return dev ? i2c_verify_adapter(dev) : NULL;
>  }
> +EXPORT_SYMBOL_GPL(i2c_acpi_find_adapter_by_handle);
>  
>  static struct i2c_client *i2c_acpi_find_client_by_adev(struct acpi_device *adev)
>  {
> diff --git a/include/linux/i2c.h b/include/linux/i2c.h
> index 1308126fc384..9808993f5fd5 100644
> --- a/include/linux/i2c.h
> +++ b/include/linux/i2c.h
> @@ -21,6 +21,7 @@
>  #include <linux/rtmutex.h>
>  #include <linux/irqdomain.h>		/* for Host Notify IRQ */
>  #include <linux/of.h>		/* for struct device_node */
> +#include <linux/acpi.h>		/* for acpi_handle */
>  #include <linux/swab.h>		/* for swab16 */
>  #include <uapi/linux/i2c.h>
>  
> @@ -981,6 +982,7 @@ bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
>  u32 i2c_acpi_find_bus_speed(struct device *dev);
>  struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
>  				       struct i2c_board_info *info);
> +struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle);
>  #else
>  static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
>  					     struct acpi_resource_i2c_serialbus **i2c)
> @@ -996,6 +998,10 @@ static inline struct i2c_client *i2c_acpi_new_device(struct device *dev,
>  {
>  	return NULL;
>  }
> +static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle h)

You should use the same argument naming as with the non-stubbed one:

static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)

Anyway looks good to me,

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Re: [net-next,v3 2/2] net: phy: sfp: enable i2c-bus detection on ACPI based systems

[Mika Westerberg]

On Mon, May 27, 2019 at 08:22:13PM -0700, Ruslan Babayev wrote:
> +	} else if (ACPI_COMPANION(&pdev->dev)) {

You can also use has_acpi_companion() here.

> +		struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
> +		struct fwnode_handle *fw = acpi_fwnode_handle(adev);
> +		struct fwnode_reference_args args;
> +		struct acpi_handle *acpi_handle;
> +		int ret;
> +
> +		ret = acpi_node_get_property_reference(fw, "i2c-bus", 0, &args);
> +		if (ACPI_FAILURE(ret) || !is_acpi_device_node(args.fwnode)) {
> +			dev_err(&pdev->dev, "missing 'i2c-bus' property\n");
> +			return -ENODEV;
>  		}
> +
> +		acpi_handle = ACPI_HANDLE_FWNODE(args.fwnode);
> +		i2c = i2c_acpi_find_adapter_by_handle(acpi_handle);
> +	}
> +
> +	if (!i2c)
> +		return -EPROBE_DEFER;
> +
> +	err = sfp_i2c_configure(sfp, i2c);
> +	if (err < 0) {
> +		i2c_put_adapter(i2c);
> +		return err;

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Re: [net-next,v3 2/2] net: phy: sfp: enable i2c-bus detection on ACPI based systems

[Russell King - ARM Linux admin]

On Mon, May 27, 2019 at 08:22:13PM -0700, Ruslan Babayev wrote:
> Lookup I2C adapter using the "i2c-bus" device property on ACPI based
> systems similar to how it's done with DT.
> 
> An example DSD describing an SFP on an ACPI based system:
> 
> Device (SFP0)
> {
>     Name (_HID, "PRP0001")
>     Name (_CRS, ResourceTemplate()
>     {
>         GpioIo(Exclusive, PullDefault, 0, 0, IoRestrictionNone,
>                "\\_SB.PCI0.RP01.GPIO", 0, ResourceConsumer)
>             { 0, 1, 2, 3, 4 }
>     })
>     Name (_DSD, Package ()
>     {
>         ToUUID ("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
>         Package () {
>             Package () { "compatible", "sff,sfp" },
>             Package () { "i2c-bus", \_SB.PCI0.RP01.I2C.MUX.CH0 },
>             Package () { "maximum-power-milliwatt", 1000 },
>             Package () { "tx-disable-gpios", Package () { ^SFP0, 0, 0, 1} },
>             Package () { "reset-gpio",       Package () { ^SFP0, 0, 1, 1} },
>             Package () { "mod-def0-gpios",   Package () { ^SFP0, 0, 2, 1} },
>             Package () { "tx-fault-gpios",   Package () { ^SFP0, 0, 3, 0} },
>             Package () { "los-gpios",        Package () { ^SFP0, 0, 4, 1} },
>         },
>     })
> }
> 
> Device (PHY0)
> {
>     Name (_HID, "PRP0001")
>     Name (_DSD, Package ()
>     {
>         ToUUID ("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
>         Package () {
>             Package () { "compatible", "ethernet-phy-ieee802.3-c45" },
>             Package () { "sfp", \_SB.PCI0.RP01.SFP0 },
>             Package () { "managed", "in-band-status" },
>             Package () { "phy-mode", "sgmii" },
>         },
>     })
> }
> 
> Signed-off-by: Ruslan Babayev <ruslan@babayev.com>
> Cc: xe-linux-external@cisco.com

Looks mostly fine to me, thanks.  A few comments below, mostly minor.
The way we handle the non-DT and non-ACPI case needs addressing though.

> ---
>  drivers/net/phy/sfp.c | 33 +++++++++++++++++++++++++--------
>  1 file changed, 25 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c
> index d4635c2178d1..7a6c8df8899b 100644
> --- a/drivers/net/phy/sfp.c
> +++ b/drivers/net/phy/sfp.c
> @@ -9,6 +9,7 @@
>  #include <linux/module.h>
>  #include <linux/mutex.h>
>  #include <linux/of.h>
> +#include <linux/acpi.h>
>  #include <linux/phy.h>
>  #include <linux/platform_device.h>
>  #include <linux/rtnetlink.h>

These includes are arranged in alphabetical order, is there a reason
why we need acpi.h out of order here?

> @@ -1783,6 +1784,7 @@ static int sfp_probe(struct platform_device *pdev)
>  {
>  	const struct sff_data *sff;
>  	struct sfp *sfp;
> +	struct i2c_adapter *i2c = NULL;

Please move this one line above, I think that will be neater.

I'm also debating whether we should have it initialised to null - see
below.

>  	bool poll = false;
>  	int irq, err, i;
>  
> @@ -1801,7 +1803,6 @@ static int sfp_probe(struct platform_device *pdev)
>  	if (pdev->dev.of_node) {
>  		struct device_node *node = pdev->dev.of_node;
>  		const struct of_device_id *id;
> -		struct i2c_adapter *i2c;
>  		struct device_node *np;
>  
>  		id = of_match_node(sfp_of_match, node);
> @@ -1818,14 +1819,30 @@ static int sfp_probe(struct platform_device *pdev)
>  
>  		i2c = of_find_i2c_adapter_by_node(np);
>  		of_node_put(np);
> -		if (!i2c)
> -			return -EPROBE_DEFER;
> -
> -		err = sfp_i2c_configure(sfp, i2c);
> -		if (err < 0) {
> -			i2c_put_adapter(i2c);
> -			return err;
> +	} else if (ACPI_COMPANION(&pdev->dev)) {
> +		struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
> +		struct fwnode_handle *fw = acpi_fwnode_handle(adev);
> +		struct fwnode_reference_args args;
> +		struct acpi_handle *acpi_handle;
> +		int ret;
> +
> +		ret = acpi_node_get_property_reference(fw, "i2c-bus", 0, &args);
> +		if (ACPI_FAILURE(ret) || !is_acpi_device_node(args.fwnode)) {
> +			dev_err(&pdev->dev, "missing 'i2c-bus' property\n");
> +			return -ENODEV;
>  		}
> +
> +		acpi_handle = ACPI_HANDLE_FWNODE(args.fwnode);
> +		i2c = i2c_acpi_find_adapter_by_handle(acpi_handle);
> +	}

If we don't have DT, and we don't have ACPI, there isn't a way that
we can find the I2C adapter, so I think we probably ought to fail the
probe here, rather than...

> +
> +	if (!i2c)
> +		return -EPROBE_DEFER;

deferring in that case.  So, basically:

	struct i2c_adapter *i2c;

	if (pdev->dev.of_node) {
		...
	} else if (ACPI_COMPANION(&pdev->dev)) {
		...
	} else {
		return -EINVAL;
	}

	if (!i2c)
		return -EPROBE_DEFER;

> +
> +	err = sfp_i2c_configure(sfp, i2c);
> +	if (err < 0) {
> +		i2c_put_adapter(i2c);
> +		return err;
>  	}
>  
>  	for (i = 0; i < GPIO_MAX; i++)
> -- 
> 2.19.2
> 
> 

-- 
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