2019-05-24 09:02:21

by Rasmus Villemoes

[permalink] [raw]
Subject: [PATCH v2 1/5] net: dsa: mv88e6xxx: introduce support for two chips using direct smi addressing

The 88e6250 (as well as 6220, 6071, 6070, 6020) do not support
multi-chip (indirect) addressing. However, one can still have two of
them on the same mdio bus, since the device only uses 16 of the 32
possible addresses, either addresses 0x00-0x0F or 0x10-0x1F depending
on the ADDR4 pin at reset [since ADDR4 is internally pulled high, the
latter is the default].

In order to prepare for supporting the 88e6250 and friends, introduce
mv88e6xxx_info::dual_chip to allow having a non-zero sw_addr while
still using direct addressing.

Signed-off-by: Rasmus Villemoes <[email protected]>
---
drivers/net/dsa/mv88e6xxx/chip.h | 6 ++++++
drivers/net/dsa/mv88e6xxx/smi.c | 25 ++++++++++++++++++++++++-
2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/drivers/net/dsa/mv88e6xxx/chip.h b/drivers/net/dsa/mv88e6xxx/chip.h
index faa3fa889f19..74777c3bc313 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.h
+++ b/drivers/net/dsa/mv88e6xxx/chip.h
@@ -112,6 +112,12 @@ struct mv88e6xxx_info {
* when it is non-zero, and use indirect access to internal registers.
*/
bool multi_chip;
+ /* Dual-chip Addressing Mode
+ * Some chips respond to only half of the 32 SMI addresses,
+ * allowing two to coexist on the same SMI interface.
+ */
+ bool dual_chip;
+
enum dsa_tag_protocol tag_protocol;

/* Mask for FromPort and ToPort value of PortVec used in ATU Move
diff --git a/drivers/net/dsa/mv88e6xxx/smi.c b/drivers/net/dsa/mv88e6xxx/smi.c
index 96f7d2685bdc..1151b5b493ea 100644
--- a/drivers/net/dsa/mv88e6xxx/smi.c
+++ b/drivers/net/dsa/mv88e6xxx/smi.c
@@ -24,6 +24,10 @@
* When ADDR is non-zero, the chip uses Multi-chip Addressing Mode, allowing
* multiple devices to share the SMI interface. In this mode it responds to only
* 2 registers, used to indirectly access the internal SMI devices.
+ *
+ * Some chips use a different scheme: Only the ADDR4 pin is used for
+ * configuration, and the device responds to 16 of the 32 SMI
+ * addresses, allowing two to coexist on the same SMI interface.
*/

static int mv88e6xxx_smi_direct_read(struct mv88e6xxx_chip *chip,
@@ -76,6 +80,23 @@ static const struct mv88e6xxx_bus_ops mv88e6xxx_smi_direct_ops = {
.write = mv88e6xxx_smi_direct_write,
};

+static int mv88e6xxx_smi_dual_direct_read(struct mv88e6xxx_chip *chip,
+ int dev, int reg, u16 *data)
+{
+ return mv88e6xxx_smi_direct_read(chip, dev + chip->sw_addr, reg, data);
+}
+
+static int mv88e6xxx_smi_dual_direct_write(struct mv88e6xxx_chip *chip,
+ int dev, int reg, u16 data)
+{
+ return mv88e6xxx_smi_direct_write(chip, dev + chip->sw_addr, reg, data);
+}
+
+static const struct mv88e6xxx_bus_ops mv88e6xxx_smi_dual_direct_ops = {
+ .read = mv88e6xxx_smi_dual_direct_read,
+ .write = mv88e6xxx_smi_dual_direct_write,
+};
+
/* Offset 0x00: SMI Command Register
* Offset 0x01: SMI Data Register
*/
@@ -144,7 +165,9 @@ static const struct mv88e6xxx_bus_ops mv88e6xxx_smi_indirect_ops = {
int mv88e6xxx_smi_init(struct mv88e6xxx_chip *chip,
struct mii_bus *bus, int sw_addr)
{
- if (sw_addr == 0)
+ if (chip->info->dual_chip)
+ chip->smi_ops = &mv88e6xxx_smi_dual_direct_ops;
+ else if (sw_addr == 0)
chip->smi_ops = &mv88e6xxx_smi_direct_ops;
else if (chip->info->multi_chip)
chip->smi_ops = &mv88e6xxx_smi_indirect_ops;
--
2.20.1


2019-05-24 14:15:29

by Andrew Lunn

[permalink] [raw]
Subject: Re: [PATCH v2 1/5] net: dsa: mv88e6xxx: introduce support for two chips using direct smi addressing

On Fri, May 24, 2019 at 09:00:24AM +0000, Rasmus Villemoes wrote:
> The 88e6250 (as well as 6220, 6071, 6070, 6020) do not support
> multi-chip (indirect) addressing. However, one can still have two of
> them on the same mdio bus, since the device only uses 16 of the 32
> possible addresses, either addresses 0x00-0x0F or 0x10-0x1F depending
> on the ADDR4 pin at reset [since ADDR4 is internally pulled high, the
> latter is the default].
>
> In order to prepare for supporting the 88e6250 and friends, introduce
> mv88e6xxx_info::dual_chip to allow having a non-zero sw_addr while
> still using direct addressing.
>
> Signed-off-by: Rasmus Villemoes <[email protected]>

Reviewed-by: Andrew Lunn <[email protected]>

Andrew

2019-05-24 17:55:35

by Vivien Didelot

[permalink] [raw]
Subject: Re: [PATCH v2 1/5] net: dsa: mv88e6xxx: introduce support for two chips using direct smi addressing

Hi Rasmus,

On Fri, 24 May 2019 09:00:24 +0000, Rasmus Villemoes <[email protected]> wrote:
> The 88e6250 (as well as 6220, 6071, 6070, 6020) do not support
> multi-chip (indirect) addressing. However, one can still have two of
> them on the same mdio bus, since the device only uses 16 of the 32
> possible addresses, either addresses 0x00-0x0F or 0x10-0x1F depending
> on the ADDR4 pin at reset [since ADDR4 is internally pulled high, the
> latter is the default].
>
> In order to prepare for supporting the 88e6250 and friends, introduce
> mv88e6xxx_info::dual_chip to allow having a non-zero sw_addr while
> still using direct addressing.
>
> Signed-off-by: Rasmus Villemoes <[email protected]>
> ---
> drivers/net/dsa/mv88e6xxx/chip.h | 6 ++++++
> drivers/net/dsa/mv88e6xxx/smi.c | 25 ++++++++++++++++++++++++-
> 2 files changed, 30 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/dsa/mv88e6xxx/chip.h b/drivers/net/dsa/mv88e6xxx/chip.h
> index faa3fa889f19..74777c3bc313 100644
> --- a/drivers/net/dsa/mv88e6xxx/chip.h
> +++ b/drivers/net/dsa/mv88e6xxx/chip.h
> @@ -112,6 +112,12 @@ struct mv88e6xxx_info {
> * when it is non-zero, and use indirect access to internal registers.
> */
> bool multi_chip;
> + /* Dual-chip Addressing Mode
> + * Some chips respond to only half of the 32 SMI addresses,
> + * allowing two to coexist on the same SMI interface.
> + */
> + bool dual_chip;
> +
> enum dsa_tag_protocol tag_protocol;
>
> /* Mask for FromPort and ToPort value of PortVec used in ATU Move
> diff --git a/drivers/net/dsa/mv88e6xxx/smi.c b/drivers/net/dsa/mv88e6xxx/smi.c
> index 96f7d2685bdc..1151b5b493ea 100644
> --- a/drivers/net/dsa/mv88e6xxx/smi.c
> +++ b/drivers/net/dsa/mv88e6xxx/smi.c
> @@ -24,6 +24,10 @@
> * When ADDR is non-zero, the chip uses Multi-chip Addressing Mode, allowing
> * multiple devices to share the SMI interface. In this mode it responds to only
> * 2 registers, used to indirectly access the internal SMI devices.
> + *
> + * Some chips use a different scheme: Only the ADDR4 pin is used for
> + * configuration, and the device responds to 16 of the 32 SMI
> + * addresses, allowing two to coexist on the same SMI interface.
> */
>
> static int mv88e6xxx_smi_direct_read(struct mv88e6xxx_chip *chip,
> @@ -76,6 +80,23 @@ static const struct mv88e6xxx_bus_ops mv88e6xxx_smi_direct_ops = {
> .write = mv88e6xxx_smi_direct_write,
> };
>
> +static int mv88e6xxx_smi_dual_direct_read(struct mv88e6xxx_chip *chip,
> + int dev, int reg, u16 *data)
> +{
> + return mv88e6xxx_smi_direct_read(chip, dev + chip->sw_addr, reg, data);

Using chip->sw_addr + dev seems more idiomatic to me than dev + chip->sw_addr.

> +}
> +
> +static int mv88e6xxx_smi_dual_direct_write(struct mv88e6xxx_chip *chip,
> + int dev, int reg, u16 data)
> +{
> + return mv88e6xxx_smi_direct_write(chip, dev + chip->sw_addr, reg, data);
> +}
> +
> +static const struct mv88e6xxx_bus_ops mv88e6xxx_smi_dual_direct_ops = {
> + .read = mv88e6xxx_smi_dual_direct_read,
> + .write = mv88e6xxx_smi_dual_direct_write,
> +};
> +
> /* Offset 0x00: SMI Command Register
> * Offset 0x01: SMI Data Register
> */
> @@ -144,7 +165,9 @@ static const struct mv88e6xxx_bus_ops mv88e6xxx_smi_indirect_ops = {
> int mv88e6xxx_smi_init(struct mv88e6xxx_chip *chip,
> struct mii_bus *bus, int sw_addr)
> {
> - if (sw_addr == 0)
> + if (chip->info->dual_chip)
> + chip->smi_ops = &mv88e6xxx_smi_dual_direct_ops;
> + else if (sw_addr == 0)
> chip->smi_ops = &mv88e6xxx_smi_direct_ops;
> else if (chip->info->multi_chip)
> chip->smi_ops = &mv88e6xxx_smi_indirect_ops;

Please submit respins (v2, v3, and so on) as independent threads,
not as a reply to the previous version.

Otherwise this looks good to me:

Reviewed-by: Vivien Didelot <[email protected]>

Thanks,
Vivien