xref: /linux/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
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 #ifdef CONFIG_STMMAC_DA
74 	value |= DMA_BUS_MODE_DA;	/* Rx has priority over tx */
75 #endif
76 
77 	if (atds)
78 		value |= DMA_BUS_MODE_ATDS;
79 
80 	writel(value, ioaddr + DMA_BUS_MODE);
81 
82 	/* In case of GMAC AXI configuration, program the DMA_AXI_BUS_MODE
83 	 * for supported bursts.
84 	 *
85 	 * Note: This is applicable only for revision GMACv3.61a. For
86 	 * older version this register is reserved and shall have no
87 	 * effect.
88 	 *
89 	 * Note:
90 	 *  For Fixed Burst Mode: if we directly write 0xFF to this
91 	 *  register using the configurations pass from platform code,
92 	 *  this would ensure that all bursts supported by core are set
93 	 *  and those which are not supported would remain ineffective.
94 	 *
95 	 *  For Non Fixed Burst Mode: provide the maximum value of the
96 	 *  burst length. Any burst equal or below the provided burst
97 	 *  length would be allowed to perform.
98 	 */
99 	writel(burst_len, ioaddr + DMA_AXI_BUS_MODE);
100 
101 	/* Mask interrupts by writing to CSR7 */
102 	writel(DMA_INTR_DEFAULT_MASK, ioaddr + DMA_INTR_ENA);
103 
104 	/* RX/TX descriptor base address lists must be written into
105 	 * DMA CSR3 and CSR4, respectively
106 	 */
107 	writel(dma_tx, ioaddr + DMA_TX_BASE_ADDR);
108 	writel(dma_rx, ioaddr + DMA_RCV_BASE_ADDR);
109 
110 	return 0;
111 }
112 
113 static void dwmac1000_dma_operation_mode(void __iomem *ioaddr, int txmode,
114 					 int rxmode)
115 {
116 	u32 csr6 = readl(ioaddr + DMA_CONTROL);
117 
118 	if (txmode == SF_DMA_MODE) {
119 		pr_debug("GMAC: enable TX store and forward mode\n");
120 		/* Transmit COE type 2 cannot be done in cut-through mode. */
121 		csr6 |= DMA_CONTROL_TSF;
122 		/* Operating on second frame increase the performance
123 		 * especially when transmit store-and-forward is used.
124 		 */
125 		csr6 |= DMA_CONTROL_OSF;
126 	} else {
127 		pr_debug("GMAC: disabling TX SF (threshold %d)\n", txmode);
128 		csr6 &= ~DMA_CONTROL_TSF;
129 		csr6 &= DMA_CONTROL_TC_TX_MASK;
130 		/* Set the transmit threshold */
131 		if (txmode <= 32)
132 			csr6 |= DMA_CONTROL_TTC_32;
133 		else if (txmode <= 64)
134 			csr6 |= DMA_CONTROL_TTC_64;
135 		else if (txmode <= 128)
136 			csr6 |= DMA_CONTROL_TTC_128;
137 		else if (txmode <= 192)
138 			csr6 |= DMA_CONTROL_TTC_192;
139 		else
140 			csr6 |= DMA_CONTROL_TTC_256;
141 	}
142 
143 	if (rxmode == SF_DMA_MODE) {
144 		pr_debug("GMAC: enable RX store and forward mode\n");
145 		csr6 |= DMA_CONTROL_RSF;
146 	} else {
147 		pr_debug("GMAC: disable RX SF mode (threshold %d)\n", rxmode);
148 		csr6 &= ~DMA_CONTROL_RSF;
149 		csr6 &= DMA_CONTROL_TC_RX_MASK;
150 		if (rxmode <= 32)
151 			csr6 |= DMA_CONTROL_RTC_32;
152 		else if (rxmode <= 64)
153 			csr6 |= DMA_CONTROL_RTC_64;
154 		else if (rxmode <= 96)
155 			csr6 |= DMA_CONTROL_RTC_96;
156 		else
157 			csr6 |= DMA_CONTROL_RTC_128;
158 	}
159 
160 	writel(csr6, ioaddr + DMA_CONTROL);
161 }
162 
163 static void dwmac1000_dump_dma_regs(void __iomem *ioaddr)
164 {
165 	int i;
166 	pr_info(" DMA registers\n");
167 	for (i = 0; i < 22; i++) {
168 		if ((i < 9) || (i > 17)) {
169 			int offset = i * 4;
170 			pr_err("\t Reg No. %d (offset 0x%x): 0x%08x\n", i,
171 			       (DMA_BUS_MODE + offset),
172 			       readl(ioaddr + DMA_BUS_MODE + offset));
173 		}
174 	}
175 }
176 
177 static unsigned int dwmac1000_get_hw_feature(void __iomem *ioaddr)
178 {
179 	return readl(ioaddr + DMA_HW_FEATURE);
180 }
181 
182 static void dwmac1000_rx_watchdog(void __iomem *ioaddr, u32 riwt)
183 {
184 	writel(riwt, ioaddr + DMA_RX_WATCHDOG);
185 }
186 
187 const struct stmmac_dma_ops dwmac1000_dma_ops = {
188 	.init = dwmac1000_dma_init,
189 	.dump_regs = dwmac1000_dump_dma_regs,
190 	.dma_mode = dwmac1000_dma_operation_mode,
191 	.enable_dma_transmission = dwmac_enable_dma_transmission,
192 	.enable_dma_irq = dwmac_enable_dma_irq,
193 	.disable_dma_irq = dwmac_disable_dma_irq,
194 	.start_tx = dwmac_dma_start_tx,
195 	.stop_tx = dwmac_dma_stop_tx,
196 	.start_rx = dwmac_dma_start_rx,
197 	.stop_rx = dwmac_dma_stop_rx,
198 	.dma_interrupt = dwmac_dma_interrupt,
199 	.get_hw_feature = dwmac1000_get_hw_feature,
200 	.rx_watchdog = dwmac1000_rx_watchdog,
201 };
202