From f30a19b828c645cdde1e7a7733dce1cab8bcb25a Mon Sep 17 00:00:00 2001 From: Rasmus Villemoes Date: Tue, 4 Jun 2019 07:34:24 +0000 Subject: [PATCH] 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. Reviewed-by: Vivien Didelot Reviewed-by: Andrew Lunn Signed-off-by: Rasmus Villemoes Signed-off-by: David S. Miller --- 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..775f8d55a962 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, chip->sw_addr + dev, 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, chip->sw_addr + dev, 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; -- 2.11.0