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 <mil...@linux.vnet.ibm.com>
---
No change from previous version
hw/ppc/pnv.c | 19 ++++++++++++++++++-
1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c
index d8d19fb065..088824fd9f 100644
--- a/hw/ppc/pnv.c
+++ b/hw/ppc/pnv.c
@@ -1900,7 +1900,24 @@ 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));
}
}
--
2.31.1
