xref: /linux/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c (revision e0bf6c5ca2d3281f231c5f0c9bf145e9513644de)
1 /*******************************************************************************
2   This is the driver for the GMAC on-chip Ethernet controller for ST SoCs.
3   DWC Ether MAC 10/100/1000 Universal version 3.41a  has been used for
4   developing this code.
5 
6   This contains the functions to handle the dma.
7 
8   Copyright (C) 2007-2009  STMicroelectronics Ltd
9 
10   This program is free software; you can redistribute it and/or modify it
11   under the terms and conditions of the GNU General Public License,
12   version 2, as published by the Free Software Foundation.
13 
14   This program is distributed in the hope it will be useful, but WITHOUT
15   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
16   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
17   more details.
18 
19   You should have received a copy of the GNU General Public License along with
20   this program; if not, write to the Free Software Foundation, Inc.,
21   51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
22 
23   The full GNU General Public License is included in this distribution in
24   the file called "COPYING".
25 
26   Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
27 *******************************************************************************/
28 
29 #include <asm/io.h>
30 #include "dwmac1000.h"
31 #include "dwmac_dma.h"
32 
33 static int dwmac1000_dma_init(void __iomem *ioaddr, int pbl, int fb, int mb,
34 			      int burst_len, u32 dma_tx, u32 dma_rx, int atds)
35 {
36 	u32 value = readl(ioaddr + DMA_BUS_MODE);
37 	int limit;
38 
39 	/* DMA SW reset */
40 	value |= DMA_BUS_MODE_SFT_RESET;
41 	writel(value, ioaddr + DMA_BUS_MODE);
42 	limit = 10;
43 	while (limit--) {
44 		if (!(readl(ioaddr + DMA_BUS_MODE) & DMA_BUS_MODE_SFT_RESET))
45 			break;
46 		mdelay(10);
47 	}
48 	if (limit < 0)
49 		return -EBUSY;
50 
51 	/*
52 	 * Set the DMA PBL (Programmable Burst Length) mode
53 	 * Before stmmac core 3.50 this mode bit was 4xPBL, and
54 	 * post 3.5 mode bit acts as 8*PBL.
55 	 * For core rev < 3.5, when the core is set for 4xPBL mode, the
56 	 * DMA transfers the data in 4, 8, 16, 32, 64 & 128 beats
57 	 * depending on pbl value.
58 	 * For core rev > 3.5, when the core is set for 8xPBL mode, the
59 	 * DMA transfers the data in 8, 16, 32, 64, 128 & 256 beats
60 	 * depending on pbl value.
61 	 */
62 	value = DMA_BUS_MODE_PBL | ((pbl << DMA_BUS_MODE_PBL_SHIFT) |
63 				    (pbl << DMA_BUS_MODE_RPBL_SHIFT));
64 
65 	/* Set the Fixed burst mode */
66 	if (fb)
67 		value |= DMA_BUS_MODE_FB;
68 
69 	/* Mixed Burst has no effect when fb is set */
70 	if (mb)
71 		value |= DMA_BUS_MODE_MB;
72 
73 	if (atds)
74 		value |= DMA_BUS_MODE_ATDS;
75 
76 	writel(value, ioaddr + DMA_BUS_MODE);
77 
78 	/* In case of GMAC AXI configuration, program the DMA_AXI_BUS_MODE
79 	 * for supported bursts.
80 	 *
81 	 * Note: This is applicable only for revision GMACv3.61a. For
82 	 * older version this register is reserved and shall have no
83 	 * effect.
84 	 *
85 	 * Note:
86 	 *  For Fixed Burst Mode: if we directly write 0xFF to this
87 	 *  register using the configurations pass from platform code,
88 	 *  this would ensure that all bursts supported by core are set
89 	 *  and those which are not supported would remain ineffective.
90 	 *
91 	 *  For Non Fixed Burst Mode: provide the maximum value of the
92 	 *  burst length. Any burst equal or below the provided burst
93 	 *  length would be allowed to perform.
94 	 */
95 	writel(burst_len, ioaddr + DMA_AXI_BUS_MODE);
96 
97 	/* Mask interrupts by writing to CSR7 */
98 	writel(DMA_INTR_DEFAULT_MASK, ioaddr + DMA_INTR_ENA);
99 
100 	/* RX/TX descriptor base address lists must be written into
101 	 * DMA CSR3 and CSR4, respectively
102 	 */
103 	writel(dma_tx, ioaddr + DMA_TX_BASE_ADDR);
104 	writel(dma_rx, ioaddr + DMA_RCV_BASE_ADDR);
105 
106 	return 0;
107 }
108 
109 static void dwmac1000_dma_operation_mode(void __iomem *ioaddr, int txmode,
110 					 int rxmode)
111 {
112 	u32 csr6 = readl(ioaddr + DMA_CONTROL);
113 
114 	if (txmode == SF_DMA_MODE) {
115 		pr_debug("GMAC: enable TX store and forward mode\n");
116 		/* Transmit COE type 2 cannot be done in cut-through mode. */
117 		csr6 |= DMA_CONTROL_TSF;
118 		/* Operating on second frame increase the performance
119 		 * especially when transmit store-and-forward is used.
120 		 */
121 		csr6 |= DMA_CONTROL_OSF;
122 	} else {
123 		pr_debug("GMAC: disabling TX SF (threshold %d)\n", txmode);
124 		csr6 &= ~DMA_CONTROL_TSF;
125 		csr6 &= DMA_CONTROL_TC_TX_MASK;
126 		/* Set the transmit threshold */
127 		if (txmode <= 32)
128 			csr6 |= DMA_CONTROL_TTC_32;
129 		else if (txmode <= 64)
130 			csr6 |= DMA_CONTROL_TTC_64;
131 		else if (txmode <= 128)
132 			csr6 |= DMA_CONTROL_TTC_128;
133 		else if (txmode <= 192)
134 			csr6 |= DMA_CONTROL_TTC_192;
135 		else
136 			csr6 |= DMA_CONTROL_TTC_256;
137 	}
138 
139 	if (rxmode == SF_DMA_MODE) {
140 		pr_debug("GMAC: enable RX store and forward mode\n");
141 		csr6 |= DMA_CONTROL_RSF;
142 	} else {
143 		pr_debug("GMAC: disable RX SF mode (threshold %d)\n", rxmode);
144 		csr6 &= ~DMA_CONTROL_RSF;
145 		csr6 &= DMA_CONTROL_TC_RX_MASK;
146 		if (rxmode <= 32)
147 			csr6 |= DMA_CONTROL_RTC_32;
148 		else if (rxmode <= 64)
149 			csr6 |= DMA_CONTROL_RTC_64;
150 		else if (rxmode <= 96)
151 			csr6 |= DMA_CONTROL_RTC_96;
152 		else
153 			csr6 |= DMA_CONTROL_RTC_128;
154 	}
155 
156 	writel(csr6, ioaddr + DMA_CONTROL);
157 }
158 
159 static void dwmac1000_dump_dma_regs(void __iomem *ioaddr)
160 {
161 	int i;
162 	pr_info(" DMA registers\n");
163 	for (i = 0; i < 22; i++) {
164 		if ((i < 9) || (i > 17)) {
165 			int offset = i * 4;
166 			pr_err("\t Reg No. %d (offset 0x%x): 0x%08x\n", i,
167 			       (DMA_BUS_MODE + offset),
168 			       readl(ioaddr + DMA_BUS_MODE + offset));
169 		}
170 	}
171 }
172 
173 static unsigned int dwmac1000_get_hw_feature(void __iomem *ioaddr)
174 {
175 	return readl(ioaddr + DMA_HW_FEATURE);
176 }
177 
178 static void dwmac1000_rx_watchdog(void __iomem *ioaddr, u32 riwt)
179 {
180 	writel(riwt, ioaddr + DMA_RX_WATCHDOG);
181 }
182 
183 const struct stmmac_dma_ops dwmac1000_dma_ops = {
184 	.init = dwmac1000_dma_init,
185 	.dump_regs = dwmac1000_dump_dma_regs,
186 	.dma_mode = dwmac1000_dma_operation_mode,
187 	.enable_dma_transmission = dwmac_enable_dma_transmission,
188 	.enable_dma_irq = dwmac_enable_dma_irq,
189 	.disable_dma_irq = dwmac_disable_dma_irq,
190 	.start_tx = dwmac_dma_start_tx,
191 	.stop_tx = dwmac_dma_stop_tx,
192 	.start_rx = dwmac_dma_start_rx,
193 	.stop_rx = dwmac_dma_stop_rx,
194 	.dma_interrupt = dwmac_dma_interrupt,
195 	.get_hw_feature = dwmac1000_get_hw_feature,
196 	.rx_watchdog = dwmac1000_rx_watchdog,
197 };
198