Messages in this thread Patch in this message | | | From | Rasmus Villemoes <> | Subject | [RFC PATCH 1/5] net: dsa: mv88e6xxx: introduce support for two chips using direct smi addressing | Date | Wed, 1 May 2019 19:32:10 +0000 |
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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 <rasmus.villemoes@prevas.dk> --- drivers/net/dsa/mv88e6xxx/chip.c | 10 +++++++--- drivers/net/dsa/mv88e6xxx/chip.h | 5 +++++ 2 files changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c index c078c791f481..f66daa77774b 100644 --- a/drivers/net/dsa/mv88e6xxx/chip.c +++ b/drivers/net/dsa/mv88e6xxx/chip.c @@ -62,6 +62,10 @@ static void assert_reg_lock(struct mv88e6xxx_chip *chip) * 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_read(struct mv88e6xxx_chip *chip, @@ -87,7 +91,7 @@ static int mv88e6xxx_smi_single_chip_read(struct mv88e6xxx_chip *chip, { int ret; - ret = mdiobus_read_nested(chip->bus, addr, reg); + ret = mdiobus_read_nested(chip->bus, addr + chip->sw_addr, reg); if (ret < 0) return ret; @@ -101,7 +105,7 @@ static int mv88e6xxx_smi_single_chip_write(struct mv88e6xxx_chip *chip, { int ret; - ret = mdiobus_write_nested(chip->bus, addr, reg, val); + ret = mdiobus_write_nested(chip->bus, addr + chip->sw_addr, reg, val); if (ret < 0) return ret; @@ -4548,7 +4552,7 @@ static struct mv88e6xxx_chip *mv88e6xxx_alloc_chip(struct device *dev) static int mv88e6xxx_smi_init(struct mv88e6xxx_chip *chip, struct mii_bus *bus, int sw_addr) { - if (sw_addr == 0) + if (sw_addr == 0 || chip->info->dual_chip) chip->smi_ops = &mv88e6xxx_smi_single_chip_ops; else if (chip->info->multi_chip) chip->smi_ops = &mv88e6xxx_smi_multi_chip_ops; diff --git a/drivers/net/dsa/mv88e6xxx/chip.h b/drivers/net/dsa/mv88e6xxx/chip.h index 546651d8c3e1..5759fffbd39c 100644 --- a/drivers/net/dsa/mv88e6xxx/chip.h +++ b/drivers/net/dsa/mv88e6xxx/chip.h @@ -123,6 +123,11 @@ 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 -- 2.20.1
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