| Message ID | 20170922171323.10348-5-f4bug@amsat.org |
|---|---|
| State | New |
| Headers | show |
| Series | [v5,1/7] hw/mdio: Generalize etraxfs MDIO bitbanging emulation | expand |
On Fri, Sep 22, 2017 at 10:13 AM, Philippe Mathieu-Daudé <f4bug@amsat.org> wrote: > From: Grant Likely <grant.likely@arm.com> > > The RST and ANEG_RST bits are commands, not settings. An operating > system will get confused (or at least u-boot does) if those bits remain > set after writing to them. Therefore, mask them out on write. > > Similarly, no bits in the ID1, ID2, and remote capability registers are > writeable; so mask them out also. > > Signed-off-by: Grant Likely <grant.likely@arm.com> > Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> > [PMD: just rebased] > --- > include/hw/net/mdio.h | 1 + > hw/net/mdio.c | 16 ++++++++++++---- > 2 files changed, 13 insertions(+), 4 deletions(-) > > diff --git a/include/hw/net/mdio.h b/include/hw/net/mdio.h > index b3b4f497c0..ed1879a728 100644 > --- a/include/hw/net/mdio.h > +++ b/include/hw/net/mdio.h > @@ -53,6 +53,7 @@ > > struct qemu_phy { > uint32_t regs[NUM_PHY_REGS]; > + const uint16_t *regs_readonly_mask; /* 0=writable, 1=read-only */ > > int link; > > diff --git a/hw/net/mdio.c b/hw/net/mdio.c > index 33bfbb4623..89a6a3a590 100644 > --- a/hw/net/mdio.c > +++ b/hw/net/mdio.c > @@ -109,17 +109,24 @@ static unsigned int mdio_phy_read(struct qemu_phy *phy, unsigned int req) > > static void mdio_phy_write(struct qemu_phy *phy, unsigned int req, unsigned int data) > { > - int regnum; > + int regnum = req & 0x1f; > + uint16_t mask = phy->regs_readonly_mask[regnum]; > > - regnum = req & 0x1f; > - D(printf("%s reg[%d] = %x\n", __func__, regnum, data)); > + D(printf("%s reg[%d] = %x; mask=%x\n", __func__, regnum, data, mask)); > switch (regnum) { > default: > - phy->regs[regnum] = data; > + phy->regs[regnum] = (phy->regs[regnum] & mask) | (data & ~mask); > break; > } > } > > +static const uint16_t default_readonly_mask[32] = { > + [PHY_CTRL] = PHY_CTRL_RST | PHY_CTRL_ANEG_RST, > + [PHY_ID1] = 0xffff, > + [PHY_ID2] = 0xffff, > + [PHY_LP_ABILITY] = 0xffff, > +}; This is what the register API is really good at :) Overall this looks fine, can we use a macro for the 32 though and then protect accesses with an assert() or if()? Alistair > + > void mdio_phy_init(struct qemu_phy *phy, uint16_t id1, uint16_t id2) > { > phy->regs[PHY_CTRL] = 0x3100; > @@ -128,6 +135,7 @@ void mdio_phy_init(struct qemu_phy *phy, uint16_t id1, uint16_t id2) > phy->regs[PHY_ID2] = id2; > /* Autonegotiation advertisement reg. */ > phy->regs[PHY_AUTONEG_ADV] = 0x01e1; > + phy->regs_readonly_mask = default_readonly_mask; > phy->link = 1; > > phy->read = mdio_phy_read; > -- > 2.14.1 > >
diff --git a/include/hw/net/mdio.h b/include/hw/net/mdio.h index b3b4f497c0..ed1879a728 100644 --- a/include/hw/net/mdio.h +++ b/include/hw/net/mdio.h @@ -53,6 +53,7 @@ struct qemu_phy { uint32_t regs[NUM_PHY_REGS]; + const uint16_t *regs_readonly_mask; /* 0=writable, 1=read-only */ int link; diff --git a/hw/net/mdio.c b/hw/net/mdio.c index 33bfbb4623..89a6a3a590 100644 --- a/hw/net/mdio.c +++ b/hw/net/mdio.c @@ -109,17 +109,24 @@ static unsigned int mdio_phy_read(struct qemu_phy *phy, unsigned int req) static void mdio_phy_write(struct qemu_phy *phy, unsigned int req, unsigned int data) { - int regnum; + int regnum = req & 0x1f; + uint16_t mask = phy->regs_readonly_mask[regnum]; - regnum = req & 0x1f; - D(printf("%s reg[%d] = %x\n", __func__, regnum, data)); + D(printf("%s reg[%d] = %x; mask=%x\n", __func__, regnum, data, mask)); switch (regnum) { default: - phy->regs[regnum] = data; + phy->regs[regnum] = (phy->regs[regnum] & mask) | (data & ~mask); break; } } +static const uint16_t default_readonly_mask[32] = { + [PHY_CTRL] = PHY_CTRL_RST | PHY_CTRL_ANEG_RST, + [PHY_ID1] = 0xffff, + [PHY_ID2] = 0xffff, + [PHY_LP_ABILITY] = 0xffff, +}; + void mdio_phy_init(struct qemu_phy *phy, uint16_t id1, uint16_t id2) { phy->regs[PHY_CTRL] = 0x3100; @@ -128,6 +135,7 @@ void mdio_phy_init(struct qemu_phy *phy, uint16_t id1, uint16_t id2) phy->regs[PHY_ID2] = id2; /* Autonegotiation advertisement reg. */ phy->regs[PHY_AUTONEG_ADV] = 0x01e1; + phy->regs_readonly_mask = default_readonly_mask; phy->link = 1; phy->read = mdio_phy_read;