Re: [PATCH v5 5/9] ppc/pnv: Wire up pca9552 GPIO pins for PCIe hotplug power control
On 11/21/23 20:09, 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. 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 Reviewed-by: Cédric Le Goater Thanks, C. --- 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)); } }
[PATCH v5 5/9] ppc/pnv: Wire up pca9552 GPIO pins for PCIe hotplug power control
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 --- 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
