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authorGiuseppe CAVALLARO <peppe.cavallaro@st.com>2012-06-04 15:22:56 -0400
committerDavid S. Miller <davem@davemloft.net>2012-06-06 12:34:56 -0400
commit3d2377144ca66c98fa220bda5f945590cf5cfdc0 (patch)
tree8254e2b99ad18dc0ac8d198fbbe3ba21dea197d1 /Documentation/networking/stmmac.txt
parentff3dd78cb8055bcb3a10e526044d8b54a773c612 (diff)
stmmac: update driver's doc
Fixed the driver's documentation that was obsolete and didn't report new platform fields (recently added). Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation/networking/stmmac.txt')
-rw-r--r--Documentation/networking/stmmac.txt44
1 files changed, 25 insertions, 19 deletions
diff --git a/Documentation/networking/stmmac.txt b/Documentation/networking/stmmac.txt
index ab1e8d7004c5..5cb9a1972460 100644
--- a/Documentation/networking/stmmac.txt
+++ b/Documentation/networking/stmmac.txt
@@ -10,8 +10,8 @@ Currently this network device driver is for all STM embedded MAC/GMAC
10(i.e. 7xxx/5xxx SoCs), SPEAr (arm), Loongson1B (mips) and XLINX XC2V3000 10(i.e. 7xxx/5xxx SoCs), SPEAr (arm), Loongson1B (mips) and XLINX XC2V3000
11FF1152AMT0221 D1215994A VIRTEX FPGA board. 11FF1152AMT0221 D1215994A VIRTEX FPGA board.
12 12
13DWC Ether MAC 10/100/1000 Universal version 3.60a (and older) and DWC Ether MAC 10/100 13DWC Ether MAC 10/100/1000 Universal version 3.60a (and older) and DWC Ether
14Universal version 4.0 have been used for developing this driver. 14MAC 10/100 Universal version 4.0 have been used for developing this driver.
15 15
16This driver supports both the platform bus and PCI. 16This driver supports both the platform bus and PCI.
17 17
@@ -54,27 +54,27 @@ net_device structure enabling the scatter/gather feature.
54When one or more packets are received, an interrupt happens. The interrupts 54When one or more packets are received, an interrupt happens. The interrupts
55are not queued so the driver has to scan all the descriptors in the ring during 55are not queued so the driver has to scan all the descriptors in the ring during
56the receive process. 56the receive process.
57This is based on NAPI so the interrupt handler signals only if there is work to be 57This is based on NAPI so the interrupt handler signals only if there is work
58done, and it exits. 58to be done, and it exits.
59Then the poll method will be scheduled at some future point. 59Then the poll method will be scheduled at some future point.
60The incoming packets are stored, by the DMA, in a list of pre-allocated socket 60The incoming packets are stored, by the DMA, in a list of pre-allocated socket
61buffers in order to avoid the memcpy (Zero-copy). 61buffers in order to avoid the memcpy (Zero-copy).
62 62
634.3) Timer-Driver Interrupt 634.3) Timer-Driver Interrupt
64Instead of having the device that asynchronously notifies the frame receptions, the 64Instead of having the device that asynchronously notifies the frame receptions,
65driver configures a timer to generate an interrupt at regular intervals. 65the driver configures a timer to generate an interrupt at regular intervals.
66Based on the granularity of the timer, the frames that are received by the device 66Based on the granularity of the timer, the frames that are received by the
67will experience different levels of latency. Some NICs have dedicated timer 67device will experience different levels of latency. Some NICs have dedicated
68device to perform this task. STMMAC can use either the RTC device or the TMU 68timer device to perform this task. STMMAC can use either the RTC device or the
69channel 2 on STLinux platforms. 69TMU channel 2 on STLinux platforms.
70The timers frequency can be passed to the driver as parameter; when change it, 70The timers frequency can be passed to the driver as parameter; when change it,
71take care of both hardware capability and network stability/performance impact. 71take care of both hardware capability and network stability/performance impact.
72Several performance tests on STM platforms showed this optimisation allows to spare 72Several performance tests on STM platforms showed this optimisation allows to
73the CPU while having the maximum throughput. 73spare the CPU while having the maximum throughput.
74 74
754.4) WOL 754.4) WOL
76Wake up on Lan feature through Magic and Unicast frames are supported for the GMAC 76Wake up on Lan feature through Magic and Unicast frames are supported for the
77core. 77GMAC core.
78 78
794.5) DMA descriptors 794.5) DMA descriptors
80Driver handles both normal and enhanced descriptors. The latter has been only 80Driver handles both normal and enhanced descriptors. The latter has been only
@@ -106,7 +106,8 @@ Several driver's information can be passed through the platform
106These are included in the include/linux/stmmac.h header file 106These are included in the include/linux/stmmac.h header file
107and detailed below as well: 107and detailed below as well:
108 108
109 struct plat_stmmacenet_data { 109struct plat_stmmacenet_data {
110 char *phy_bus_name;
110 int bus_id; 111 int bus_id;
111 int phy_addr; 112 int phy_addr;
112 int interface; 113 int interface;
@@ -124,19 +125,24 @@ and detailed below as well:
124 void (*bus_setup)(void __iomem *ioaddr); 125 void (*bus_setup)(void __iomem *ioaddr);
125 int (*init)(struct platform_device *pdev); 126 int (*init)(struct platform_device *pdev);
126 void (*exit)(struct platform_device *pdev); 127 void (*exit)(struct platform_device *pdev);
128 void *custom_cfg;
129 void *custom_data;
127 void *bsp_priv; 130 void *bsp_priv;
128 }; 131 };
129 132
130Where: 133Where:
134 o phy_bus_name: phy bus name to attach to the stmmac.
131 o bus_id: bus identifier. 135 o bus_id: bus identifier.
132 o phy_addr: the physical address can be passed from the platform. 136 o phy_addr: the physical address can be passed from the platform.
133 If it is set to -1 the driver will automatically 137 If it is set to -1 the driver will automatically
134 detect it at run-time by probing all the 32 addresses. 138 detect it at run-time by probing all the 32 addresses.
135 o interface: PHY device's interface. 139 o interface: PHY device's interface.
136 o mdio_bus_data: specific platform fields for the MDIO bus. 140 o mdio_bus_data: specific platform fields for the MDIO bus.
137 o pbl: the Programmable Burst Length is maximum number of beats to 141 o dma_cfg: internal DMA parameters
142 o pbl: the Programmable Burst Length is maximum number of beats to
138 be transferred in one DMA transaction. 143 be transferred in one DMA transaction.
139 GMAC also enables the 4xPBL by default. 144 GMAC also enables the 4xPBL by default.
145 o fixed_burst/mixed_burst/burst_len
140 o clk_csr: fixed CSR Clock range selection. 146 o clk_csr: fixed CSR Clock range selection.
141 o has_gmac: uses the GMAC core. 147 o has_gmac: uses the GMAC core.
142 o enh_desc: if sets the MAC will use the enhanced descriptor structure. 148 o enh_desc: if sets the MAC will use the enhanced descriptor structure.
@@ -160,8 +166,9 @@ Where:
160 this is sometime necessary on some platforms (e.g. ST boxes) 166 this is sometime necessary on some platforms (e.g. ST boxes)
161 where the HW needs to have set some PIO lines or system cfg 167 where the HW needs to have set some PIO lines or system cfg
162 registers. 168 registers.
163 o custom_cfg: this is a custom configuration that can be passed while 169 o custom_cfg/custom_data: this is a custom configuration that can be passed
164 initialising the resources. 170 while initialising the resources.
171 o bsp_priv: another private poiter.
165 172
166For MDIO bus The we have: 173For MDIO bus The we have:
167 174
@@ -180,7 +187,6 @@ Where:
180 o irqs: list of IRQs, one per PHY. 187 o irqs: list of IRQs, one per PHY.
181 o probed_phy_irq: if irqs is NULL, use this for probed PHY. 188 o probed_phy_irq: if irqs is NULL, use this for probed PHY.
182 189
183
184For DMA engine we have the following internal fields that should be 190For DMA engine we have the following internal fields that should be
185tuned according to the HW capabilities. 191tuned according to the HW capabilities.
186 192