For power10-rainier, a pca9552 device is used for PCIe slot hotplug
power control by the Power Hypervisor code. The code expects that
some time after it enables power to a PCIe slot by asserting one of
the pca9552 GPIO pins 0-4, it should see a "power good" signal asserted
on one of pca9552 GPIO pins 5-9.
To simulate this behavior, we simply connect the GPIO outputs for
pins 0-4 to the GPIO inputs for pins 5-9.
Each PCIe slot is assigned 3 GPIO pins on the pca9552 device, for
control of up to 5 PCIe slots. The per-slot signal names are:
SLOTx_EN.......PHYP uses this as an output to enable
slot power. We connect this to the
SLOTx_PG pin to simulate a PGOOD signal.
SLOTx_PG.......PHYP uses this as in input to detect
PGOOD for the slot. For our purposes
we just connect this to the SLOTx_EN
output.
SLOTx_Control..PHYP uses this as an output to prevent
a race condition in the real hotplug
circuitry, but we can ignore this output
for simulation.
Signed-off-by: Glenn Miles <milesg@linux.vnet.ibm.com>
---
Changes from previous version:
- Code moved from pnv_chip_power10_realize to pnv_rainier_i2c_init
hw/ppc/pnv.c | 20 ++++++++++++++++++--
1 file changed, 18 insertions(+), 2 deletions(-)
diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c
index 9cefcd0fd6..80d25fc1bd 100644
--- a/hw/ppc/pnv.c
+++ b/hw/ppc/pnv.c
@@ -1898,8 +1898,24 @@ static void pnv_rainier_i2c_init(PnvMachineState *pnv)
* Add a PCA9552 I2C device for PCIe hotplug control
* to engine 2, bus 1, address 0x63
*/
- i2c_slave_create_simple(chip10->i2c[2].busses[1],
- "pca9552", 0x63);
+ I2CSlave *hotplug = i2c_slave_create_simple(chip10->i2c[2].busses[1],
+ "pca9552", 0x63);
+
+ /*
+ * Connect PCA9552 GPIO pins 0-4 (SLOTx_EN) outputs to GPIO pins 5-9
+ * (SLOTx_PG) inputs in order to fake the pgood state of PCIe slots
+ * after hypervisor code sets a SLOTx_EN pin high.
+ */
+ qdev_connect_gpio_out(DEVICE(hotplug), 0,
+ qdev_get_gpio_in(DEVICE(hotplug), 5));
+ qdev_connect_gpio_out(DEVICE(hotplug), 1,
+ qdev_get_gpio_in(DEVICE(hotplug), 6));
+ qdev_connect_gpio_out(DEVICE(hotplug), 2,
+ qdev_get_gpio_in(DEVICE(hotplug), 7));
+ qdev_connect_gpio_out(DEVICE(hotplug), 3,
+ qdev_get_gpio_in(DEVICE(hotplug), 8));
+ qdev_connect_gpio_out(DEVICE(hotplug), 4,
+ qdev_get_gpio_in(DEVICE(hotplug), 9));
}
}
--
2.31.1On 11/21/23 00:51, Glenn Miles wrote: > For power10-rainier, a pca9552 device is used for PCIe slot hotplug > power control by the Power Hypervisor code. The code expects that > some time after it enables power to a PCIe slot by asserting one of > the pca9552 GPIO pins 0-4, it should see a "power good" signal asserted > on one of pca9552 GPIO pins 5-9. And this is what OPAL is not doing : https://github.com/open-power/skiboot/blob/master/platforms/astbmc/rainier.c#L65 Correct ? > To simulate this behavior, we simply connect the GPIO outputs for > pins 0-4 to the GPIO inputs for pins 5-9. > > Each PCIe slot is assigned 3 GPIO pins on the pca9552 device, for > control of up to 5 PCIe slots. The per-slot signal names are: > > SLOTx_EN.......PHYP uses this as an output to enable > slot power. We connect this to the > SLOTx_PG pin to simulate a PGOOD signal. > SLOTx_PG.......PHYP uses this as in input to detect > PGOOD for the slot. For our purposes > we just connect this to the SLOTx_EN > output. > SLOTx_Control..PHYP uses this as an output to prevent > a race condition in the real hotplug > circuitry, but we can ignore this output > for simulation. > > Signed-off-by: Glenn Miles <milesg@linux.vnet.ibm.com> > --- > > Changes from previous version: > - Code moved from pnv_chip_power10_realize to pnv_rainier_i2c_init > > hw/ppc/pnv.c | 20 ++++++++++++++++++-- > 1 file changed, 18 insertions(+), 2 deletions(-) > > diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c > index 9cefcd0fd6..80d25fc1bd 100644 > --- a/hw/ppc/pnv.c > +++ b/hw/ppc/pnv.c > @@ -1898,8 +1898,24 @@ static void pnv_rainier_i2c_init(PnvMachineState *pnv) > * Add a PCA9552 I2C device for PCIe hotplug control > * to engine 2, bus 1, address 0x63 > */ > - i2c_slave_create_simple(chip10->i2c[2].busses[1], > - "pca9552", 0x63); > + I2CSlave *hotplug = i2c_slave_create_simple(chip10->i2c[2].busses[1], > + "pca9552", 0x63); hotplug ? why not dev simply ? Thanks, C. > + > + /* > + * Connect PCA9552 GPIO pins 0-4 (SLOTx_EN) outputs to GPIO pins 5-9 > + * (SLOTx_PG) inputs in order to fake the pgood state of PCIe slots > + * after hypervisor code sets a SLOTx_EN pin high. > + */ > + qdev_connect_gpio_out(DEVICE(hotplug), 0, > + qdev_get_gpio_in(DEVICE(hotplug), 5)); > + qdev_connect_gpio_out(DEVICE(hotplug), 1, > + qdev_get_gpio_in(DEVICE(hotplug), 6)); > + qdev_connect_gpio_out(DEVICE(hotplug), 2, > + qdev_get_gpio_in(DEVICE(hotplug), 7)); > + qdev_connect_gpio_out(DEVICE(hotplug), 3, > + qdev_get_gpio_in(DEVICE(hotplug), 8)); > + qdev_connect_gpio_out(DEVICE(hotplug), 4, > + qdev_get_gpio_in(DEVICE(hotplug), 9)); > } > } >
On Tue, 2023-11-21 at 19:36 +0100, Cédric Le Goater wrote: > On 11/21/23 00:51, Glenn Miles wrote: > > For power10-rainier, a pca9552 device is used for PCIe slot hotplug > > power control by the Power Hypervisor code. The code expects that > > some time after it enables power to a PCIe slot by asserting one of > > the pca9552 GPIO pins 0-4, it should see a "power good" signal > > asserted > > on one of pca9552 GPIO pins 5-9. > > And this is what OPAL is not doing : > > > https://github.com/open-power/skiboot/blob/master/platforms/astbmc/rainier.c#L65 > > Correct ? > Ah, yes, I believe you are correct! > > To simulate this behavior, we simply connect the GPIO outputs for > > pins 0-4 to the GPIO inputs for pins 5-9. > > > > Each PCIe slot is assigned 3 GPIO pins on the pca9552 device, for > > control of up to 5 PCIe slots. The per-slot signal names are: > > > > SLOTx_EN.......PHYP uses this as an output to enable > > slot power. We connect this to the > > SLOTx_PG pin to simulate a PGOOD signal. > > SLOTx_PG.......PHYP uses this as in input to detect > > PGOOD for the slot. For our purposes > > we just connect this to the SLOTx_EN > > output. > > SLOTx_Control..PHYP uses this as an output to prevent > > a race condition in the real hotplug > > circuitry, but we can ignore this output > > for simulation. > > > > Signed-off-by: Glenn Miles <milesg@linux.vnet.ibm.com> > > --- > > > > Changes from previous version: > > - Code moved from pnv_chip_power10_realize to > > pnv_rainier_i2c_init > > > > hw/ppc/pnv.c | 20 ++++++++++++++++++-- > > 1 file changed, 18 insertions(+), 2 deletions(-) > > > > diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c > > index 9cefcd0fd6..80d25fc1bd 100644 > > --- a/hw/ppc/pnv.c > > +++ b/hw/ppc/pnv.c > > @@ -1898,8 +1898,24 @@ static void > > pnv_rainier_i2c_init(PnvMachineState *pnv) > > * Add a PCA9552 I2C device for PCIe hotplug control > > * to engine 2, bus 1, address 0x63 > > */ > > - i2c_slave_create_simple(chip10->i2c[2].busses[1], > > - "pca9552", 0x63); > > + I2CSlave *hotplug = i2c_slave_create_simple(chip10- > > >i2c[2].busses[1], > > + "pca9552", 0x63); > > hotplug ? why not dev simply ? > > > Thanks, > > C. > > Sure, dev is fine. I'll change it. Thanks, Glenn > > > + > > + /* > > + * Connect PCA9552 GPIO pins 0-4 (SLOTx_EN) outputs to > > GPIO pins 5-9 > > + * (SLOTx_PG) inputs in order to fake the pgood state of > > PCIe slots > > + * after hypervisor code sets a SLOTx_EN pin high. > > + */ > > + qdev_connect_gpio_out(DEVICE(hotplug), 0, > > + qdev_get_gpio_in(DEVICE(hotplug), > > 5)); > > + qdev_connect_gpio_out(DEVICE(hotplug), 1, > > + qdev_get_gpio_in(DEVICE(hotplug), > > 6)); > > + qdev_connect_gpio_out(DEVICE(hotplug), 2, > > + qdev_get_gpio_in(DEVICE(hotplug), > > 7)); > > + qdev_connect_gpio_out(DEVICE(hotplug), 3, > > + qdev_get_gpio_in(DEVICE(hotplug), > > 8)); > > + qdev_connect_gpio_out(DEVICE(hotplug), 4, > > + qdev_get_gpio_in(DEVICE(hotplug), > > 9)); > > } > > } > >
Adding Reza. On 11/21/23 21:03, Miles Glenn wrote: > On Tue, 2023-11-21 at 19:36 +0100, Cédric Le Goater wrote: >> On 11/21/23 00:51, Glenn Miles wrote: >>> For power10-rainier, a pca9552 device is used for PCIe slot hotplug >>> power control by the Power Hypervisor code. The code expects that >>> some time after it enables power to a PCIe slot by asserting one of >>> the pca9552 GPIO pins 0-4, it should see a "power good" signal >>> asserted >>> on one of pca9552 GPIO pins 5-9. >> >> And this is what OPAL is not doing : >> >> >> https://github.com/open-power/skiboot/blob/master/platforms/astbmc/rainier.c#L65 >> >> Correct ? >> > > Ah, yes, I believe you are correct! Thanks, C.
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