[PATCH v2 5/7] hw/nvram: Update at24c EEPROM init function in NPCM7xx boards

Hao Wu posted 7 patches 4 years, 3 months ago
Maintainers: Paolo Bonzini <pbonzini@redhat.com>, Havard Skinnemoen <hskinnemoen@google.com>, Alistair Francis <alistair@alistair23.me>, Peter Maydell <peter.maydell@linaro.org>, Thomas Huth <thuth@redhat.com>, Tyrone Ting <kfting@nuvoton.com>, Laurent Vivier <lvivier@redhat.com>
There is a newer version of this series
[PATCH v2 5/7] hw/nvram: Update at24c EEPROM init function in NPCM7xx boards
Posted by Hao Wu 4 years, 3 months ago
We made 3 changes to the at24c_eeprom_init function in
npcm7xx_boards.c:

1. We allow the function to take a I2CBus* as parameter. This allows
   us to attach an EEPROM device behind an I2C mux which is not
   possible with the old method.

2. We make at24c EEPROMs are backed by drives so that we can
   specify the content of the EEPROMs.

3. Instead of using i2c address as unit number, This patch assigns
   unique unit numbers for each eeproms in each board. This avoids
   conflict in providing multiple eeprom contents with the same address.
   In the old method if we specify two drives with the same unit number,
   the following error will occur: `Device with id 'none85' exists`.

Signed-off-by: Hao Wu <wuhaotsh@google.com>
---
 hw/arm/npcm7xx_boards.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/hw/arm/npcm7xx_boards.c b/hw/arm/npcm7xx_boards.c
index a656169f61..cdb52b9922 100644
--- a/hw/arm/npcm7xx_boards.c
+++ b/hw/arm/npcm7xx_boards.c
@@ -107,13 +107,18 @@ static I2CBus *npcm7xx_i2c_get_bus(NPCM7xxState *soc, uint32_t num)
     return I2C_BUS(qdev_get_child_bus(DEVICE(&soc->smbus[num]), "i2c-bus"));
 }
 
-static void at24c_eeprom_init(NPCM7xxState *soc, int bus, uint8_t addr,
-                              uint32_t rsize)
+static void at24c_eeprom_init(I2CBus *i2c_bus, int bus, uint8_t addr,
+                              uint32_t rsize, int unit_number)
 {
-    I2CBus *i2c_bus = npcm7xx_i2c_get_bus(soc, bus);
     I2CSlave *i2c_dev = i2c_slave_new("at24c-eeprom", addr);
     DeviceState *dev = DEVICE(i2c_dev);
+    BlockInterfaceType type = IF_NONE;
+    DriveInfo *dinfo;
 
+    dinfo = drive_get(type, bus, unit_number);
+    if (dinfo) {
+        qdev_prop_set_drive(dev, "drive", blk_by_legacy_dinfo(dinfo));
+    }
     qdev_prop_set_uint32(dev, "rom-size", rsize);
     i2c_slave_realize_and_unref(i2c_dev, i2c_bus, &error_abort);
 }
@@ -220,8 +225,8 @@ static void quanta_gsj_i2c_init(NPCM7xxState *soc)
     i2c_slave_create_simple(npcm7xx_i2c_get_bus(soc, 3), "tmp105", 0x5c);
     i2c_slave_create_simple(npcm7xx_i2c_get_bus(soc, 4), "tmp105", 0x5c);
 
-    at24c_eeprom_init(soc, 9, 0x55, 8192);
-    at24c_eeprom_init(soc, 10, 0x55, 8192);
+    at24c_eeprom_init(npcm7xx_i2c_get_bus(soc, 9), 9, 0x55, 8192, 0);
+    at24c_eeprom_init(npcm7xx_i2c_get_bus(soc, 10), 10, 0x55, 8192, 1);
 
     /*
      * i2c-11:
-- 
2.33.0.1079.g6e70778dc9-goog


Re: [PATCH v2 5/7] hw/nvram: Update at24c EEPROM init function in NPCM7xx boards
Posted by Peter Maydell 4 years, 3 months ago
On Thu, 21 Oct 2021 at 19:40, Hao Wu <wuhaotsh@google.com> wrote:
>
> We made 3 changes to the at24c_eeprom_init function in
> npcm7xx_boards.c:
>
> 1. We allow the function to take a I2CBus* as parameter. This allows
>    us to attach an EEPROM device behind an I2C mux which is not
>    possible with the old method.
>
> 2. We make at24c EEPROMs are backed by drives so that we can
>    specify the content of the EEPROMs.
>
> 3. Instead of using i2c address as unit number, This patch assigns
>    unique unit numbers for each eeproms in each board. This avoids
>    conflict in providing multiple eeprom contents with the same address.
>    In the old method if we specify two drives with the same unit number,
>    the following error will occur: `Device with id 'none85' exists`.
>
> Signed-off-by: Hao Wu <wuhaotsh@google.com>
> ---
>  hw/arm/npcm7xx_boards.c | 15 ++++++++++-----
>  1 file changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/hw/arm/npcm7xx_boards.c b/hw/arm/npcm7xx_boards.c
> index a656169f61..cdb52b9922 100644
> --- a/hw/arm/npcm7xx_boards.c
> +++ b/hw/arm/npcm7xx_boards.c
> @@ -107,13 +107,18 @@ static I2CBus *npcm7xx_i2c_get_bus(NPCM7xxState *soc, uint32_t num)
>      return I2C_BUS(qdev_get_child_bus(DEVICE(&soc->smbus[num]), "i2c-bus"));
>  }
>
> -static void at24c_eeprom_init(NPCM7xxState *soc, int bus, uint8_t addr,
> -                              uint32_t rsize)
> +static void at24c_eeprom_init(I2CBus *i2c_bus, int bus, uint8_t addr,
> +                              uint32_t rsize, int unit_number)
>  {
> -    I2CBus *i2c_bus = npcm7xx_i2c_get_bus(soc, bus);
>      I2CSlave *i2c_dev = i2c_slave_new("at24c-eeprom", addr);
>      DeviceState *dev = DEVICE(i2c_dev);
> +    BlockInterfaceType type = IF_NONE;

Why make this a variable? We only use it in one place...

-- PMM

Re: [PATCH v2 5/7] hw/nvram: Update at24c EEPROM init function in NPCM7xx boards
Posted by Hao Wu 4 years, 3 months ago
On Mon, Nov 1, 2021 at 10:41 AM Peter Maydell <peter.maydell@linaro.org>
wrote:

> On Thu, 21 Oct 2021 at 19:40, Hao Wu <wuhaotsh@google.com> wrote:
> >
> > We made 3 changes to the at24c_eeprom_init function in
> > npcm7xx_boards.c:
> >
> > 1. We allow the function to take a I2CBus* as parameter. This allows
> >    us to attach an EEPROM device behind an I2C mux which is not
> >    possible with the old method.
> >
> > 2. We make at24c EEPROMs are backed by drives so that we can
> >    specify the content of the EEPROMs.
> >
> > 3. Instead of using i2c address as unit number, This patch assigns
> >    unique unit numbers for each eeproms in each board. This avoids
> >    conflict in providing multiple eeprom contents with the same address.
> >    In the old method if we specify two drives with the same unit number,
> >    the following error will occur: `Device with id 'none85' exists`.
> >
> > Signed-off-by: Hao Wu <wuhaotsh@google.com>
> > ---
> >  hw/arm/npcm7xx_boards.c | 15 ++++++++++-----
> >  1 file changed, 10 insertions(+), 5 deletions(-)
> >
> > diff --git a/hw/arm/npcm7xx_boards.c b/hw/arm/npcm7xx_boards.c
> > index a656169f61..cdb52b9922 100644
> > --- a/hw/arm/npcm7xx_boards.c
> > +++ b/hw/arm/npcm7xx_boards.c
> > @@ -107,13 +107,18 @@ static I2CBus *npcm7xx_i2c_get_bus(NPCM7xxState
> *soc, uint32_t num)
> >      return I2C_BUS(qdev_get_child_bus(DEVICE(&soc->smbus[num]),
> "i2c-bus"));
> >  }
> >
> > -static void at24c_eeprom_init(NPCM7xxState *soc, int bus, uint8_t addr,
> > -                              uint32_t rsize)
> > +static void at24c_eeprom_init(I2CBus *i2c_bus, int bus, uint8_t addr,
> > +                              uint32_t rsize, int unit_number)
> >  {
> > -    I2CBus *i2c_bus = npcm7xx_i2c_get_bus(soc, bus);
> >      I2CSlave *i2c_dev = i2c_slave_new("at24c-eeprom", addr);
> >      DeviceState *dev = DEVICE(i2c_dev);
> > +    BlockInterfaceType type = IF_NONE;
>
> Why make this a variable? We only use it in one place...
>
You're right, we can actually inline it.

>
> -- PMM
>
Re: [PATCH v2 5/7] hw/nvram: Update at24c EEPROM init function in NPCM7xx boards
Posted by Thomas Huth 4 years, 3 months ago
On 01/11/2021 18.47, Hao Wu wrote:
> 
> 
> On Mon, Nov 1, 2021 at 10:41 AM Peter Maydell <peter.maydell@linaro.org 
> <mailto:peter.maydell@linaro.org>> wrote:
> 
>     On Thu, 21 Oct 2021 at 19:40, Hao Wu <wuhaotsh@google.com
>     <mailto:wuhaotsh@google.com>> wrote:
>      >
>      > We made 3 changes to the at24c_eeprom_init function in
>      > npcm7xx_boards.c:
>      >
>      > 1. We allow the function to take a I2CBus* as parameter. This allows
>      >    us to attach an EEPROM device behind an I2C mux which is not
>      >    possible with the old method.
>      >
>      > 2. We make at24c EEPROMs are backed by drives so that we can
>      >    specify the content of the EEPROMs.
>      >
>      > 3. Instead of using i2c address as unit number, This patch assigns
>      >    unique unit numbers for each eeproms in each board. This avoids
>      >    conflict in providing multiple eeprom contents with the same address.
>      >    In the old method if we specify two drives with the same unit number,
>      >    the following error will occur: `Device with id 'none85' exists`.
>      >
>      > Signed-off-by: Hao Wu <wuhaotsh@google.com <mailto:wuhaotsh@google.com>>
>      > ---
>      >  hw/arm/npcm7xx_boards.c | 15 ++++++++++-----
>      >  1 file changed, 10 insertions(+), 5 deletions(-)
>      >
>      > diff --git a/hw/arm/npcm7xx_boards.c b/hw/arm/npcm7xx_boards.c
>      > index a656169f61..cdb52b9922 100644
>      > --- a/hw/arm/npcm7xx_boards.c
>      > +++ b/hw/arm/npcm7xx_boards.c
>      > @@ -107,13 +107,18 @@ static I2CBus *npcm7xx_i2c_get_bus(NPCM7xxState
>     *soc, uint32_t num)
>      >      return I2C_BUS(qdev_get_child_bus(DEVICE(&soc->smbus[num]),
>     "i2c-bus"));
>      >  }
>      >
>      > -static void at24c_eeprom_init(NPCM7xxState *soc, int bus, uint8_t addr,
>      > -                              uint32_t rsize)
>      > +static void at24c_eeprom_init(I2CBus *i2c_bus, int bus, uint8_t addr,
>      > +                              uint32_t rsize, int unit_number)
>      >  {
>      > -    I2CBus *i2c_bus = npcm7xx_i2c_get_bus(soc, bus);
>      >      I2CSlave *i2c_dev = i2c_slave_new("at24c-eeprom", addr);
>      >      DeviceState *dev = DEVICE(i2c_dev);
>      > +    BlockInterfaceType type = IF_NONE;
> 
>     Why make this a variable? We only use it in one place...
> 
> You're right, we can actually inline it.

Actually, please do *not* use IF_NONE for such stuff. See the discussion 
here for details:

  https://lists.gnu.org/archive/html/qemu-devel/2021-11/msg00970.html

  Thomas


Re: [PATCH v2 5/7] hw/nvram: Update at24c EEPROM init function in NPCM7xx boards
Posted by Hao Wu 4 years, 3 months ago
Thanks for the comment. I'll upload a new version using IF_OTHER as
discussed in that thread.

I don't know if adding the assertion for type != IF_NONE is a good idea now
so I didn't add that.
If you think that's good I can add it as well.

On Wed, Nov 3, 2021 at 2:13 AM Thomas Huth <thuth@redhat.com> wrote:

> On 01/11/2021 18.47, Hao Wu wrote:
> >
> >
> > On Mon, Nov 1, 2021 at 10:41 AM Peter Maydell <peter.maydell@linaro.org
> > <mailto:peter.maydell@linaro.org>> wrote:
> >
> >     On Thu, 21 Oct 2021 at 19:40, Hao Wu <wuhaotsh@google.com
> >     <mailto:wuhaotsh@google.com>> wrote:
> >      >
> >      > We made 3 changes to the at24c_eeprom_init function in
> >      > npcm7xx_boards.c:
> >      >
> >      > 1. We allow the function to take a I2CBus* as parameter. This
> allows
> >      >    us to attach an EEPROM device behind an I2C mux which is not
> >      >    possible with the old method.
> >      >
> >      > 2. We make at24c EEPROMs are backed by drives so that we can
> >      >    specify the content of the EEPROMs.
> >      >
> >      > 3. Instead of using i2c address as unit number, This patch assigns
> >      >    unique unit numbers for each eeproms in each board. This avoids
> >      >    conflict in providing multiple eeprom contents with the same
> address.
> >      >    In the old method if we specify two drives with the same unit
> number,
> >      >    the following error will occur: `Device with id 'none85'
> exists`.
> >      >
> >      > Signed-off-by: Hao Wu <wuhaotsh@google.com <mailto:
> wuhaotsh@google.com>>
> >      > ---
> >      >  hw/arm/npcm7xx_boards.c | 15 ++++++++++-----
> >      >  1 file changed, 10 insertions(+), 5 deletions(-)
> >      >
> >      > diff --git a/hw/arm/npcm7xx_boards.c b/hw/arm/npcm7xx_boards.c
> >      > index a656169f61..cdb52b9922 100644
> >      > --- a/hw/arm/npcm7xx_boards.c
> >      > +++ b/hw/arm/npcm7xx_boards.c
> >      > @@ -107,13 +107,18 @@ static I2CBus
> *npcm7xx_i2c_get_bus(NPCM7xxState
> >     *soc, uint32_t num)
> >      >      return I2C_BUS(qdev_get_child_bus(DEVICE(&soc->smbus[num]),
> >     "i2c-bus"));
> >      >  }
> >      >
> >      > -static void at24c_eeprom_init(NPCM7xxState *soc, int bus,
> uint8_t addr,
> >      > -                              uint32_t rsize)
> >      > +static void at24c_eeprom_init(I2CBus *i2c_bus, int bus, uint8_t
> addr,
> >      > +                              uint32_t rsize, int unit_number)
> >      >  {
> >      > -    I2CBus *i2c_bus = npcm7xx_i2c_get_bus(soc, bus);
> >      >      I2CSlave *i2c_dev = i2c_slave_new("at24c-eeprom", addr);
> >      >      DeviceState *dev = DEVICE(i2c_dev);
> >      > +    BlockInterfaceType type = IF_NONE;
> >
> >     Why make this a variable? We only use it in one place...
> >
> > You're right, we can actually inline it.
>
> Actually, please do *not* use IF_NONE for such stuff. See the discussion
> here for details:
>
>   https://lists.gnu.org/archive/html/qemu-devel/2021-11/msg00970.html
>
>   Thomas
>
>
Re: [PATCH v2 5/7] hw/nvram: Update at24c EEPROM init function in NPCM7xx boards
Posted by Peter Maydell 4 years, 3 months ago
On Wed, 3 Nov 2021 at 21:52, Hao Wu <wuhaotsh@google.com> wrote:
>
> Thanks for the comment. I'll upload a new version using IF_OTHER as discussed in that thread.
>
> I don't know if adding the assertion for type != IF_NONE is a good idea now so I didn't add that.
> If you think that's good I can add it as well.

We would have to fix the existing use of IF_NONE in the tree
before we could add an assert. (Awkward because it will
break commandlines for that existing use.)

-- PMM