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stmmac: improve and up-to-date the documentation

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This patch adds new information for the driver
especially about its platform structure fields.

Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Giuseppe CAVALLARO 2011-07-20 00:05:24 +00:00 committed by David S. Miller
parent 36bcfe7d74
commit 557e2a394d
1 changed files with 133 additions and 61 deletions
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194
Documentation/networking/stmmac.txt
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@ -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. (Synopsys IP blocks); it has been fully tested on STLinux platforms.
Currently this network device driver is for all STM embedded MAC/GMAC 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 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 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. the CPU while having the maximum throughput.
4.4) WOL 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. core.
4.5) DMA descriptors 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. The driver is compatible with PAL to work with PHY and GPHY devices.
4.9) Platform information 4.9) Platform information
Several information came from the platform; please refer to the Several driver's information can be passed through the platform
driver's Header file in include/linux directory. 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 bus_id;
int phy_addr;
int interface;
struct stmmac_mdio_bus_data *mdio_bus_data;
int pbl; int pbl;
int clk_csr; int clk_csr;
int has_gmac; int has_gmac;
@ -103,67 +107,135 @@ struct plat_stmmacenet_data {
int tx_coe; int tx_coe;
int bugged_jumbo; int bugged_jumbo;
int pmt; int pmt;
void (*fix_mac_speed)(void *priv, unsigned int speed); int force_sf_dma_mode;
void (*bus_setup)(unsigned long ioaddr); void (*fix_mac_speed)(void *priv, unsigned int speed);
#ifdef CONFIG_STM_DRIVERS void (*bus_setup)(void __iomem *ioaddr);
struct stm_pad_config *pad_config; int (*init)(struct platform_device *pdev);
#endif void (*exit)(struct platform_device *pdev);
void *bsp_priv; void *bsp_priv;
}; };
Where: Where:
- pbl (Programmable Burst Length) is maximum number of o bus_id: bus identifier.
beats to be transferred in one DMA transaction. o phy_addr: the physical address can be passed from the platform.
GMAC also enables the 4xPBL by default. If it is set to -1 the driver will automatically
- fix_mac_speed and bus_setup are used to configure internal target detect it at run-time by probing all the 32 addresses.
registers (on STM platforms); o interface: PHY device's interface.
- has_gmac: GMAC core is on board (get it at run-time in the next step); o mdio_bus_data: specific platform fields for the MDIO bus.
- bus_id: bus identifier. o pbl: the Programmable Burst Length is maximum number of beats to
- tx_coe: core is able to perform the tx csum in HW. be transferred in one DMA transaction.
- enh_desc: if sets the MAC will use the enhanced descriptor structure. GMAC also enables the 4xPBL by default.
- clk_csr: CSR Clock range selection. o clk_csr: CSR Clock range selection.
- bugged_jumbo: some HWs are not able to perform the csum in HW for o has_gmac: uses the GMAC core.
over-sized frames due to limited buffer sizes. Setting this o enh_desc: if sets the MAC will use the enhanced descriptor structure.
flag the csum will be done in SW on JUMBO frames. 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.
struct plat_stmmacphy_data { The we have:
int bus_id;
int phy_addr; struct stmmac_mdio_bus_data {
unsigned int phy_mask; int bus_id;
int interface; int (*phy_reset)(void *priv);
int (*phy_reset)(void *priv); unsigned int phy_mask;
void *priv; int *irqs;
}; int probed_phy_irq;
};
Where: Where:
- bus_id: bus identifier; o bus_id: bus identifier;
- phy_addr: physical address used for the attached phy device; o phy_reset: hook to reset the phy device attached to the bus.
set it to -1 to get it at run-time; o phy_mask: phy mask passed when register the MDIO bus within the driver.
- interface: physical MII interface mode; o irqs: list of IRQs, one per PHY.
- phy_reset: hook to reset HW function. o probed_phy_irq: if irqs is NULL, use this for probed PHY.
SOURCES: Below an example how the structures above are using on ST platforms.
- 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: static struct plat_stmmacenet_data stxYYY_ethernet_platform_data = {
- XGMAC controller is not supported. .pbl = 32,
- Review the timer optimisation code to use an embedded device that seems to be .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. available in new chip generations.