From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bin Meng Date: Sat, 5 Oct 2019 13:03:24 +0800 Subject: [U-Boot] [PATCH 026/126] pci: sandbox: Move the emulators into their own node In-Reply-To: <20190925145750.200592-27-sjg@chromium.org> References: <20190925145750.200592-1-sjg@chromium.org> <20190925145750.200592-27-sjg@chromium.org> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Wed, Sep 25, 2019 at 10:58 PM Simon Glass wrote: > > Sandbox i2c works using emulation drivers which are currently children of pci > the i2c device: pci > > pci-controller { > pci at 1f,0 { > compatible = "pci-generic"; > reg = <0xf800 0 0 0 0>; > emul at 1f,0 { > compatible = "sandbox,swap-case"; > }; > }; > }; > > In this case the emulation device is attached to pci device on address > f800 (device 1f, function 0) and provides the swap-case functionality. > > However this is not ideal, since every device on a PCI bus has a child > device. This is only really the case for sandbox, but we want to avoid > special-case code for sandbox. > > Worse, child devices cannot be probed before their parents. This forces > us to use 'find' rather than 'get' to obtain the emulator device. In fact > the emulator devices are never probed. There is code in > sandbox_pci_emul_post_probe() which tries to track when emulators are > active, but at present this does not work. > > A better approach seems to be to add a separate node elsewhere in the > device tree, an 'emulation parent'. This could be given a bogus address > (such as -1) to hide the emulators away from the 'pci' command, but it > seems better to keep it at the root node to avoid such hacks. > > Then we can use a phandle to point from the evice to the correct typo: device > emulator, and only on sandbox. The code to find an emulator does not > interfere with normal pci operation. > > Add a new UCLASS_PCI_EMUL_PARENT uclass which allows finding an emulator > given a bus, and finding a bus given an emulator. Update the existing > device trees and the code for finding an emulator. > > This brings PCI emulators more into line with I2C. > > Signed-off-by: Simon Glass > --- > > arch/sandbox/dts/sandbox.dtsi | 11 +++++++--- > arch/sandbox/dts/test.dts | 38 +++++++++++++++++++++++------------ > doc/driver-model/pci-info.rst | 23 +++++++++++---------- > drivers/pci/pci-emul-uclass.c | 37 ++++++++++++++++++++++++++++------ > include/dm/uclass-id.h | 1 + > 5 files changed, 77 insertions(+), 33 deletions(-) > > diff --git a/arch/sandbox/dts/sandbox.dtsi b/arch/sandbox/dts/sandbox.dtsi > index c6d5650c20b..f09bc70b0da 100644 > --- a/arch/sandbox/dts/sandbox.dtsi > +++ b/arch/sandbox/dts/sandbox.dtsi > @@ -103,9 +103,14 @@ > pci at 1f,0 { > compatible = "pci-generic"; > reg = <0xf800 0 0 0 0>; > - emul at 1f,0 { > - compatible = "sandbox,swap-case"; > - }; > + sandbox,emul = <&swap_case_emul>; > + }; > + }; > + > + emul { > + compatible = "sandbox,pci-emul-parent"; > + swap_case_emul: emul at 1f,0 { > + compatible = "sandbox,swap-case"; > }; > }; > > diff --git a/arch/sandbox/dts/test.dts b/arch/sandbox/dts/test.dts > index 5669ede7051..a2e75981f0b 100644 > --- a/arch/sandbox/dts/test.dts > +++ b/arch/sandbox/dts/test.dts > @@ -452,24 +452,31 @@ > pci at 0,0 { > compatible = "pci-generic"; > reg = <0x0000 0 0 0 0>; > - emul at 0,0 { > - compatible = "sandbox,swap-case"; > - }; > + sandbox,emul = <&swap_case_emul0>; &swap_case_emul0_0 > }; > pci at 1,0 { > compatible = "pci-generic"; > reg = <0x0800 0 0 0 0>; > - emul at 0,0 { > - compatible = "sandbox,swap-case"; > - use-ea; > - }; > + sandbox,emul = <&swap_case_emul1>; &swap_case_emul0_1 > }; > pci at 1f,0 { > compatible = "pci-generic"; > reg = <0xf800 0 0 0 0>; > - emul at 1f,0 { > - compatible = "sandbox,swap-case"; > - }; > + sandbox,emul = <&swap_case_emul1f>; &swap_case_emul0_1f > + }; > + }; > + > + pci-emul0 { > + compatible = "sandbox,pci-emul-parent"; > + swap_case_emul0: emul at 0,0 { > + compatible = "sandbox,swap-case"; > + }; > + swap_case_emul1: emul at 1,0 { > + compatible = "sandbox,swap-case"; > + use-ea; > + }; > + swap_case_emul1f: emul at 1f,0 { > + compatible = "sandbox,swap-case"; > }; > }; > > @@ -499,9 +506,14 @@ > pci at 1f,0 { > compatible = "pci-generic"; > reg = <0xf800 0 0 0 0>; > - emul at 1f,0 { > - compatible = "sandbox,swap-case"; > - }; > + sandbox,emul = <&swap_case_emul2_1f>; > + }; > + }; > + > + pci-emul2 { > + compatible = "sandbox,pci-emul-parent"; > + swap_case_emul2_1f: emul2 at 1f,0 { > + compatible = "sandbox,swap-case"; > }; > }; > > diff --git a/doc/driver-model/pci-info.rst b/doc/driver-model/pci-info.rst > index d93ab8b61d5..f39ff990a67 100644 > --- a/doc/driver-model/pci-info.rst > +++ b/doc/driver-model/pci-info.rst > @@ -113,14 +113,17 @@ Sandbox > ------- > > With sandbox we need a device emulator for each device on the bus since there > -is no real PCI bus. This works by looking in the device tree node for a > -driver. For example:: > - > +is no real PCI bus. This works by looking in the device tree node for an > +emulator driver. For example:: > > pci at 1f,0 { > compatible = "pci-generic"; > reg = <0xf800 0 0 0 0>; > - emul at 1f,0 { > + sandbox,emul = <&emul_1f>; > + }; > + pci-emul { > + compatible = "sandbox,pci-emul-parent"; > + emul_1f: emul at 1f,0 { > compatible = "sandbox,swap-case"; > }; > }; > @@ -130,14 +133,16 @@ Note that the first cell in the 'reg' value is the bus/device/function. See > PCI_BDF() for the encoding (it is also specified in the IEEE Std 1275-1994 > PCI bus binding document, v2.1) > > +The pci-emul node should go outside the pci bus node, since otherwise it will > +be scanned as a PCI device, causing confusion. > + > When this bus is scanned we will end up with something like this:: > > `- * pci-controller @ 05c660c8, 0 > `- pci at 1f,0 @ 05c661c8, 63488 > - `- emul at 1f,0 @ 05c662c8 > + `- emul at 1f,0 @ 05c662c8 > > -When accesses go to the pci at 1f,0 device they are forwarded to its child, the > -emulator. > +When accesses go to the pci at 1f,0 device they are forwarded to its emulator. > > The sandbox PCI drivers also support dynamic driver binding, allowing device > driver to declare the driver binding information via U_BOOT_PCI_DEVICE(), > @@ -164,7 +169,3 @@ When this bus is scanned we will end up with something like this:: > pci [ + ] pci_sandbo |-- pci-controller1 > pci_emul [ ] sandbox_sw | |-- sandbox_swap_case_emul > pci_emul [ ] sandbox_sw | `-- sandbox_swap_case_emul > - > -Note the difference from the statically declared device nodes is that the > -device is directly attached to the host controller, instead of via a container > -device like pci at 1f,0. > diff --git a/drivers/pci/pci-emul-uclass.c b/drivers/pci/pci-emul-uclass.c > index 38227583547..f918e9a52fd 100644 > --- a/drivers/pci/pci-emul-uclass.c > +++ b/drivers/pci/pci-emul-uclass.c > @@ -10,6 +10,7 @@ > #include > #include > #include > +#include > > struct sandbox_pci_emul_priv { > int dev_count; > @@ -30,13 +31,15 @@ int sandbox_pci_get_emul(struct udevice *bus, pci_dev_t find_devfn, > } > *containerp = dev; > > - if (device_get_uclass_id(dev) == UCLASS_PCI_GENERIC) { > - ret = device_find_first_child(dev, emulp); > - if (ret) > - return ret; > - } else { > + /* > + * TODO(sjg at chromium.org): This code needs a comment as I'm not sure > + * why UCLASS_PCI_GENERIC devices end up being their own emulators. I > + * left this code as is. > + */ This code comes from: commit 4345998ae9dfad7ba0beb54ad4322134557504a9 Author: Bin Meng Date: Fri Aug 3 01:14:45 2018 -0700 pci: sandbox: Support dynamically binding device driver I think the comments can be removed :) > + ret = uclass_find_device_by_phandle(UCLASS_PCI_EMUL, dev, > + "sandbox,emul", emulp); > + if (ret && device_get_uclass_id(dev) != UCLASS_PCI_GENERIC) > *emulp = dev; > - } > > return *emulp ? 0 : -ENODEV; > } > @@ -68,3 +71,25 @@ UCLASS_DRIVER(pci_emul) = { > .pre_remove = sandbox_pci_emul_pre_remove, > .priv_auto_alloc_size = sizeof(struct sandbox_pci_emul_priv), > }; > + > +/* > + * This uclass is a child of the pci bus. Its platdata is not defined here so > + * is defined by its parent, UCLASS_PCI, which uses struct pci_child_platdata. > + * See per_child_platdata_auto_alloc_size in UCLASS_DRIVER(pci). > + */ > +UCLASS_DRIVER(pci_emul_parent) = { > + .id = UCLASS_PCI_EMUL_PARENT, > + .name = "pci_emul_parent", > + .post_bind = dm_scan_fdt_dev, > +}; > + > +static const struct udevice_id pci_emul_parent_ids[] = { > + { .compatible = "sandbox,pci-emul-parent" }, > + { } > +}; > + > +U_BOOT_DRIVER(pci_emul_parent_drv) = { > + .name = "pci_emul_parent_drv", > + .id = UCLASS_PCI_EMUL_PARENT, > + .of_match = pci_emul_parent_ids, > +}; > diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h > index d4d96106b37..f431f3bf294 100644 > --- a/include/dm/uclass-id.h > +++ b/include/dm/uclass-id.h > @@ -23,6 +23,7 @@ enum uclass_id { > UCLASS_I2C_EMUL, /* sandbox I2C device emulator */ > UCLASS_I2C_EMUL_PARENT, /* parent for I2C device emulators */ > UCLASS_PCI_EMUL, /* sandbox PCI device emulator */ > + UCLASS_PCI_EMUL_PARENT, /* parent for PCI device emulators */ > UCLASS_USB_EMUL, /* sandbox USB bus device emulator */ > UCLASS_AXI_EMUL, /* sandbox AXI bus device emulator */ > > -- Other than the issues above, Reviewed-by: Bin Meng Tested-by: Bin Meng