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Diffstat (limited to 'doc/driver-model/UDM-pci.txt')
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diff --git a/doc/driver-model/UDM-pci.txt b/doc/driver-model/UDM-pci.txt deleted file mode 100644 index 1dce99de3d..0000000000 --- a/doc/driver-model/UDM-pci.txt +++ /dev/null @@ -1,253 +0,0 @@ -The U-Boot Driver Model Project -=============================== -PCI subsystem analysis -====================== - -Pavel Herrmann <morpheus.ibis@gmail.com> -2012-03-17 - -I) Overview ------------ - - U-Boot already supports multiple PCI busses, stored in a linked-list of - pci_controller structures. This structure contains generic driver data, bus - interface operations and private data for the driver. - - Bus interface operations for PCI are (names are self-explanatory): - - read_byte() - read_word() - read_dword() - write_byte() - write_word() - write_dword() - - Each driver has to implement dword operations, and either implement word and - byte operations, or use shared $operation_config_$type_via_dword (eg. - read_config_byte_via_dword and similar) function. These functions are used - for config space I/O (read_config_dword and similar functions of the PCI - subsystem), which is used to configure the connected devices for standard MMIO - operations. All data transfers by respective device drivers are then done by - MMIO - - Each driver also defines a separate init function, which has unique symbol - name, and thus more drivers can be compiled in without colliding. This init - function is typically called from pci_init_board(), different for each - particular board. - - Some boards also define a function called fixup_irq, which gets called after - scanning the PCI bus for devices, and should dismiss any interrupts. - - Several drivers are also located in arch/ and should be moved to drivers/pci. - -II) Approach ------------- - - The pci_controller structure needs to be broken down to fit the new driver - model. Due to a large number of members, this will be done through three - distinct accessors, one for memory regions, one for config table and one for - everything else. That will make the pci_ops structure look like this: - - struct pci_ops { - int (*read_byte)(struct instance *bus, pci_dev_t *dev, int addr, - u8 *buf); - int (*read_word)(struct instance *bus, pci_dev_t *dev, int addr, - u16 *buf); - int (*read_dword)(struct instance *bus, pci_dev_t *dev, int addr, - u32 *buf); - int (*write_byte)(struct instance *bus, pci_dev_t *dev, int addr, - u8 val); - int (*write_byte)(struct instance *bus, pci_dev_t *dev, int addr, - u8 val); - int (*write_dword)(struct instance *bus, pci_dev_t *dev, int addr, - u32 val); - void (*fixup_irq)(struct instance *bus, pci_dev_t *dev); - struct pci_region* (*get_region)(struct instance *, uint num); - struct pci_config_table* (*get_cfg_table)(struct instance *bus); - uint (*get_option)(struct instance * bus, enum pci_option_code op); - } - - enum pci_option_code { - PCI_OPT_BUS_NUMBER=0, - PCI_OPT_REGION_COUNT, - PCI_OPT_INDIRECT_TYPE, - PCI_OPT_AUTO_MEM, - PCI_OPT_AUTO_IO, - PCI_OPT_AUTO_PREFETCH, - PCI_OPT_AUTO_FB, - PCI_OPT_CURRENT_BUS, - PCI_OPT_CFG_ADDR, - } - - The return value for get_option will be an unsigned integer value for any - option code. If the option currently is a pointer to pci_region, it will - return an index for get_region function. Special case has to be made for - PCI_OPT_CFG_ADDR, which should be interpreted as a pointer, but it is only - used for equality in find_hose_by_cfg_addr, and thus can be returned as an - uint. Other function using cfg_addr value are read/write functions for - specific drivers (especially ops for indirect bridges), and thus have access - to private_data of the driver instance. - - The config table accessor will return a pointer to a NULL-terminated array of - pci_config_table, which is supplied by the board in platform_data, or NULL if - the board didn't specify one. This table is used to override PnP - auto-initialization, or to specific initialization functions for non-PNP - devices. - - Transparent PCI-PCI bridges will get their own driver, and will forward all - operations to operations of their parent bus. This however makes it - impossible to use instances to identify devices, as not all devices will be - directly visible to the respective bus driver. - - Init functions of controller drivers will be moved to their respective - probe() functions, in accordance to the driver model. - - The PCI core will handle all mapping functions currently found in pci.c, as - well as proxy functions for read/write operations of the drivers. The PCI - core will also handle bus scanning and device configuration. - - The PnP helper functions currently in pci_auto.c will also be a part of PCI - core, but they will be exposed only to PCI controller drivers, not to other - device drivers. - - The PCI API for device drivers will remain largely unchanged, most drivers - will require no changes at all, and all modifications will be limited to - changing the pci_controlle into instance*. - -III) Analysis of in-tree drivers --------------------------------- - - A) drivers in drivers/pci/ - -------------------------- - - pci_indirect.c - -------------- - Shared driver for indirect PCI bridges, several CONFIG macros - will - require significant cleanup. - - pci_sh4.c - --------- - Shared init function for SH4 drivers, uses dword for read/write ops. - - pci_sh7751.c - ------------ - Standard driver, uses SH4 shared init. - - pci_sh7780.c - ------------ - Standard driver, uses SH4 shared init. - - tsi108_pci.c - ------------ - Standard driver, uses dword for read/write ops. - - fsl_pci_init.c - -------------- - Driver for PCI and PCI-e, uses indirect functions. - - pci_ftpci100.c - -------------- - Standard driver, uses indirect functions, has separate scan/setup - functions. - - B) driver in arch/ - ------------------ - - x86/lib/pci_type1.c - ------------------- - Standard driver, specifies all read/write functions separately. - - m68k/cpu/mcf5445x/pci.c - ----------------------- - Standard driver, specifies all read/write functions separately. - - m68k/cpu/mcf547x_8x/pci.c - ------------------------- - Standard driver, specifies all read/write functions separately. - - powerpc/cpu/mpc824x/pci.c - ------------------------- - Standard driver, uses indirect functions, does not setup HW. - - powerpc/cpu/mpc8260/pci.c - ------------------------- - Standard driver, uses indirect functions. - - powerpc/cpu/ppc4xx/4xx_pci.c - ---------------------------- - Standard driver, uses indirect functions. - - powerpc/cpu/ppc4xx/4xx_pcie.c - ----------------------------- - PCI-e driver, specifies all read/write functions separately. - - powerpc/cpu/mpc83xx/pci.c - ------------------------- - Standard driver, uses indirect functions. - - powerpc/cpu/mpc83xx/pcie.c - -------------------------- - PCI-e driver, specifies all read/write functions separately. - - powerpc/cpu/mpc5xxx/pci_mpc5200.c - --------------------------------- - Standard driver, uses dword for read/write ops. - - powerpc/cpu/mpc512x/pci.c - ------------------------- - Standard driver, uses indirect functions. - - powerpc/cpu/mpc85xx/pci.c - ------------------------- - Standard driver, uses indirect functions, has two busses. - - C) drivers in board/ - -------------------- - - eltec/elppc/pci.c - ----------------- - Standard driver, uses indirect functions. - - amirix/ap1000/pci.c - ------------------- - Standard driver, specifies all read/write functions separately. - - prodrive/p3mx/pci.c - ------------------- - Standard driver, uses dword for read/write ops, has two busses. - - esd/cpci750/pci.c - ----------------- - Standard driver, uses dword for read/write ops, has two busses. - - esd/common/pci.c - ---------------- - Standard driver, uses dword for read/write ops. - - dave/common/pci.c - ----------------- - Standard driver, uses dword for read/write ops. - - ppmc7xx/pci.c - ------------- - Standard driver, uses indirect functions. - - Marvell/db64360/pci.c - --------------------- - Standard driver, uses dword for read/write ops, has two busses. - - Marvell/db64460/pci.c - --------------------- - Standard driver, uses dword for read/write ops, has two busses. - - evb64260/pci.c - -------------- - Standard driver, uses dword for read/write ops, has two busses. - - armltd/integrator/pci.c - ----------------------- - Standard driver, specifies all read/write functions separately. - - All drivers will be moved to drivers/pci. Several drivers seem - similar/identical, especially those located under board, and may be merged - into one. |