From 6f86885a74584f069db95bd6043d9497388808b4 Mon Sep 17 00:00:00 2001 From: Glenn Miles Date: Mon, 5 Feb 2024 17:40:16 +1000 Subject: [PATCH] ppc/pnv: Wire up pca9552 GPIO pins for PCIe hotplug power control MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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. Reviewed-by: Cédric Le Goater Signed-off-by: Glenn Miles Signed-off-by: Nicholas Piggin --- hw/ppc/pnv.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c index 78f5c6262a..97bdfb2d1e 100644 --- a/hw/ppc/pnv.c +++ b/hw/ppc/pnv.c @@ -1900,7 +1900,19 @@ 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 *dev = 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(dev), 0, qdev_get_gpio_in(DEVICE(dev), 5)); + qdev_connect_gpio_out(DEVICE(dev), 1, qdev_get_gpio_in(DEVICE(dev), 6)); + qdev_connect_gpio_out(DEVICE(dev), 2, qdev_get_gpio_in(DEVICE(dev), 7)); + qdev_connect_gpio_out(DEVICE(dev), 3, qdev_get_gpio_in(DEVICE(dev), 8)); + qdev_connect_gpio_out(DEVICE(dev), 4, qdev_get_gpio_in(DEVICE(dev), 9)); } }