diff options
Diffstat (limited to 'Documentation/networking/stmmac.txt')
| -rw-r--r-- | Documentation/networking/stmmac.txt | 200 |
1 files changed, 136 insertions, 64 deletions
diff --git a/Documentation/networking/stmmac.txt b/Documentation/networking/stmmac.txt index 80a7a3454902..57a24108b845 100644 --- a/Documentation/networking/stmmac.txt +++ b/Documentation/networking/stmmac.txt @@ -7,7 +7,7 @@ This is the driver for the MAC 10/100/1000 on-chip Ethernet controllers (Synopsys IP blocks); it has been fully tested on STLinux platforms. Currently this network device driver is for all STM embedded MAC/GMAC -(7xxx SoCs). Other platforms start using it i.e. ARM SPEAr. +(i.e. 7xxx/5xxx SoCs) and it's known working on other platforms i.e. ARM SPEAr. DWC Ether MAC 10/100/1000 Universal version 3.41a and DWC Ether MAC 10/100 Universal version 4.0 have been used for developing the first code @@ -71,7 +71,7 @@ Several performance tests on STM platforms showed this optimisation allows to sp the CPU while having the maximum throughput. 4.4) WOL -Wake up on Lan feature through Magic Frame is only supported for the GMAC +Wake up on Lan feature through Magic and Unicast frames are supported for the GMAC core. 4.5) DMA descriptors @@ -91,11 +91,15 @@ LRO is not supported. The driver is compatible with PAL to work with PHY and GPHY devices. 4.9) Platform information -Several information came from the platform; please refer to the -driver's Header file in include/linux directory. +Several driver's information can be passed through the platform +These are included in the include/linux/stmmac.h header file +and detailed below as well: -struct plat_stmmacenet_data { + struct plat_stmmacenet_data { int bus_id; + int phy_addr; + int interface; + struct stmmac_mdio_bus_data *mdio_bus_data; int pbl; int clk_csr; int has_gmac; @@ -103,67 +107,135 @@ struct plat_stmmacenet_data { int tx_coe; int bugged_jumbo; int pmt; - void (*fix_mac_speed)(void *priv, unsigned int speed); - void (*bus_setup)(unsigned long ioaddr); -#ifdef CONFIG_STM_DRIVERS - struct stm_pad_config *pad_config; -#endif - void *bsp_priv; -}; + int force_sf_dma_mode; + void (*fix_mac_speed)(void *priv, unsigned int speed); + void (*bus_setup)(void __iomem *ioaddr); + int (*init)(struct platform_device *pdev); + void (*exit)(struct platform_device *pdev); + void *bsp_priv; + }; Where: -- pbl (Programmable Burst Length) is maximum number of - beats to be transferred in one DMA transaction. - GMAC also enables the 4xPBL by default. -- fix_mac_speed and bus_setup are used to configure internal target - registers (on STM platforms); -- has_gmac: GMAC core is on board (get it at run-time in the next step); -- bus_id: bus identifier. -- tx_coe: core is able to perform the tx csum in HW. -- enh_desc: if sets the MAC will use the enhanced descriptor structure. -- clk_csr: CSR Clock range selection. -- bugged_jumbo: some HWs are not able to perform the csum in HW for - over-sized frames due to limited buffer sizes. Setting this - flag the csum will be done in SW on JUMBO frames. - -struct plat_stmmacphy_data { - int bus_id; - int phy_addr; - unsigned int phy_mask; - int interface; - int (*phy_reset)(void *priv); - void *priv; -}; + o bus_id: bus identifier. + o phy_addr: the physical address can be passed from the platform. + If it is set to -1 the driver will automatically + detect it at run-time by probing all the 32 addresses. + o interface: PHY device's interface. + o mdio_bus_data: specific platform fields for the MDIO bus. + o pbl: the Programmable Burst Length is maximum number of beats to + be transferred in one DMA transaction. + GMAC also enables the 4xPBL by default. + o clk_csr: CSR Clock range selection. + o has_gmac: uses the GMAC core. + o enh_desc: if sets the MAC will use the enhanced descriptor structure. + o tx_coe: core is able to perform the tx csum in HW. + o bugged_jumbo: some HWs are not able to perform the csum in HW for + over-sized frames due to limited buffer sizes. + Setting this flag the csum will be done in SW on + JUMBO frames. + o pmt: core has the embedded power module (optional). + o force_sf_dma_mode: force DMA to use the Store and Forward mode + instead of the Threshold. + o fix_mac_speed: this callback is used for modifying some syscfg registers + (on ST SoCs) according to the link speed negotiated by the + physical layer . + o bus_setup: perform HW setup of the bus. For example, on some ST platforms + this field is used to configure the AMBA bridge to generate more + efficient STBus traffic. + o init/exit: callbacks used for calling a custom initialisation; + this is sometime necessary on some platforms (e.g. ST boxes) + where the HW needs to have set some PIO lines or system cfg + registers. + o custom_cfg: this is a custom configuration that can be passed while + initialising the resources. + +The we have: + + struct stmmac_mdio_bus_data { + int bus_id; + int (*phy_reset)(void *priv); + unsigned int phy_mask; + int *irqs; + int probed_phy_irq; + }; Where: -- bus_id: bus identifier; -- phy_addr: physical address used for the attached phy device; - set it to -1 to get it at run-time; -- interface: physical MII interface mode; -- phy_reset: hook to reset HW function. - -SOURCES: -- Kconfig -- Makefile -- stmmac_main.c: main network device driver; -- stmmac_mdio.c: mdio functions; -- stmmac_ethtool.c: ethtool support; -- stmmac_timer.[ch]: timer code used for mitigating the driver dma interrupts - Only tested on ST40 platforms based. -- stmmac.h: private driver structure; -- common.h: common definitions and VFTs; -- descs.h: descriptor structure definitions; -- dwmac1000_core.c: GMAC core functions; -- dwmac1000_dma.c: dma functions for the GMAC chip; -- dwmac1000.h: specific header file for the GMAC; -- dwmac100_core: MAC 100 core and dma code; -- dwmac100_dma.c: dma funtions for the MAC chip; -- dwmac1000.h: specific header file for the MAC; -- dwmac_lib.c: generic DMA functions shared among chips -- enh_desc.c: functions for handling enhanced descriptors -- norm_desc.c: functions for handling normal descriptors - -TODO: -- XGMAC controller is not supported. -- Review the timer optimisation code to use an embedded device that seems to be + o bus_id: bus identifier; + o phy_reset: hook to reset the phy device attached to the bus. + o phy_mask: phy mask passed when register the MDIO bus within the driver. + o irqs: list of IRQs, one per PHY. + o probed_phy_irq: if irqs is NULL, use this for probed PHY. + +Below an example how the structures above are using on ST platforms. + + static struct plat_stmmacenet_data stxYYY_ethernet_platform_data = { + .pbl = 32, + .has_gmac = 0, + .enh_desc = 0, + .fix_mac_speed = stxYYY_ethernet_fix_mac_speed, + | + |-> to write an internal syscfg + | on this platform when the + | link speed changes from 10 to + | 100 and viceversa + .init = &stmmac_claim_resource, + | + |-> On ST SoC this calls own "PAD" + | manager framework to claim + | all the resources necessary + | (GPIO ...). The .custom_cfg field + | is used to pass a custom config. +}; + +Below the usage of the stmmac_mdio_bus_data: on this SoC, in fact, +there are two MAC cores: one MAC is for MDIO Bus/PHY emulation +with fixed_link support. + +static struct stmmac_mdio_bus_data stmmac1_mdio_bus = { + .bus_id = 1, + | + |-> phy device on the bus_id 1 + .phy_reset = phy_reset; + | + |-> function to provide the phy_reset on this board + .phy_mask = 0, +}; + +static struct fixed_phy_status stmmac0_fixed_phy_status = { + .link = 1, + .speed = 100, + .duplex = 1, +}; + +During the board's device_init we can configure the first +MAC for fixed_link by calling: + fixed_phy_add(PHY_POLL, 1, &stmmac0_fixed_phy_status));) +and the second one, with a real PHY device attached to the bus, +by using the stmmac_mdio_bus_data structure (to provide the id, the +reset procedure etc). + +4.10) List of source files: + o Kconfig + o Makefile + o stmmac_main.c: main network device driver; + o stmmac_mdio.c: mdio functions; + o stmmac_ethtool.c: ethtool support; + o stmmac_timer.[ch]: timer code used for mitigating the driver dma interrupts + Only tested on ST40 platforms based. + o stmmac.h: private driver structure; + o common.h: common definitions and VFTs; + o descs.h: descriptor structure definitions; + o dwmac1000_core.c: GMAC core functions; + o dwmac1000_dma.c: dma functions for the GMAC chip; + o dwmac1000.h: specific header file for the GMAC; + o dwmac100_core: MAC 100 core and dma code; + o dwmac100_dma.c: dma funtions for the MAC chip; + o dwmac1000.h: specific header file for the MAC; + o dwmac_lib.c: generic DMA functions shared among chips + o enh_desc.c: functions for handling enhanced descriptors + o norm_desc.c: functions for handling normal descriptors + +5) TODO: + o XGMAC is not supported. + o Review the timer optimisation code to use an embedded device that will be available in new chip generations. |