1 /* Altera TSE SGDMA and MSGDMA Linux driver
2  * Copyright (C) 2014 Altera Corporation. All rights reserved
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms and conditions of the GNU General Public License,
6  * version 2, as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11  * more details.
12  *
13  * You should have received a copy of the GNU General Public License along with
14  * this program.  If not, see <http://www.gnu.org/licenses/>.
15  */
16 
17 #include <linux/netdevice.h>
18 #include "altera_utils.h"
19 #include "altera_tse.h"
20 #include "altera_msgdmahw.h"
21 #include "altera_msgdma.h"
22 
23 /* No initialization work to do for MSGDMA */
24 int msgdma_initialize(struct altera_tse_private *priv)
25 {
26 	return 0;
27 }
28 
29 void msgdma_uninitialize(struct altera_tse_private *priv)
30 {
31 }
32 
33 void msgdma_start_rxdma(struct altera_tse_private *priv)
34 {
35 }
36 
37 void msgdma_reset(struct altera_tse_private *priv)
38 {
39 	int counter;
40 
41 	/* Reset Rx mSGDMA */
42 	csrwr32(MSGDMA_CSR_STAT_MASK, priv->rx_dma_csr,
43 		msgdma_csroffs(status));
44 	csrwr32(MSGDMA_CSR_CTL_RESET, priv->rx_dma_csr,
45 		msgdma_csroffs(control));
46 
47 	counter = 0;
48 	while (counter++ < ALTERA_TSE_SW_RESET_WATCHDOG_CNTR) {
49 		if (tse_bit_is_clear(priv->rx_dma_csr, msgdma_csroffs(status),
50 				     MSGDMA_CSR_STAT_RESETTING))
51 			break;
52 		udelay(1);
53 	}
54 
55 	if (counter >= ALTERA_TSE_SW_RESET_WATCHDOG_CNTR)
56 		netif_warn(priv, drv, priv->dev,
57 			   "TSE Rx mSGDMA resetting bit never cleared!\n");
58 
59 	/* clear all status bits */
60 	csrwr32(MSGDMA_CSR_STAT_MASK, priv->rx_dma_csr, msgdma_csroffs(status));
61 
62 	/* Reset Tx mSGDMA */
63 	csrwr32(MSGDMA_CSR_STAT_MASK, priv->tx_dma_csr,
64 		msgdma_csroffs(status));
65 
66 	csrwr32(MSGDMA_CSR_CTL_RESET, priv->tx_dma_csr,
67 		msgdma_csroffs(control));
68 
69 	counter = 0;
70 	while (counter++ < ALTERA_TSE_SW_RESET_WATCHDOG_CNTR) {
71 		if (tse_bit_is_clear(priv->tx_dma_csr, msgdma_csroffs(status),
72 				     MSGDMA_CSR_STAT_RESETTING))
73 			break;
74 		udelay(1);
75 	}
76 
77 	if (counter >= ALTERA_TSE_SW_RESET_WATCHDOG_CNTR)
78 		netif_warn(priv, drv, priv->dev,
79 			   "TSE Tx mSGDMA resetting bit never cleared!\n");
80 
81 	/* clear all status bits */
82 	csrwr32(MSGDMA_CSR_STAT_MASK, priv->tx_dma_csr, msgdma_csroffs(status));
83 }
84 
85 void msgdma_disable_rxirq(struct altera_tse_private *priv)
86 {
87 	tse_clear_bit(priv->rx_dma_csr, msgdma_csroffs(control),
88 		      MSGDMA_CSR_CTL_GLOBAL_INTR);
89 }
90 
91 void msgdma_enable_rxirq(struct altera_tse_private *priv)
92 {
93 	tse_set_bit(priv->rx_dma_csr, msgdma_csroffs(control),
94 		    MSGDMA_CSR_CTL_GLOBAL_INTR);
95 }
96 
97 void msgdma_disable_txirq(struct altera_tse_private *priv)
98 {
99 	tse_clear_bit(priv->tx_dma_csr, msgdma_csroffs(control),
100 		      MSGDMA_CSR_CTL_GLOBAL_INTR);
101 }
102 
103 void msgdma_enable_txirq(struct altera_tse_private *priv)
104 {
105 	tse_set_bit(priv->tx_dma_csr, msgdma_csroffs(control),
106 		    MSGDMA_CSR_CTL_GLOBAL_INTR);
107 }
108 
109 void msgdma_clear_rxirq(struct altera_tse_private *priv)
110 {
111 	csrwr32(MSGDMA_CSR_STAT_IRQ, priv->rx_dma_csr, msgdma_csroffs(status));
112 }
113 
114 void msgdma_clear_txirq(struct altera_tse_private *priv)
115 {
116 	csrwr32(MSGDMA_CSR_STAT_IRQ, priv->tx_dma_csr, msgdma_csroffs(status));
117 }
118 
119 /* return 0 to indicate transmit is pending */
120 int msgdma_tx_buffer(struct altera_tse_private *priv, struct tse_buffer *buffer)
121 {
122 	csrwr32(lower_32_bits(buffer->dma_addr), priv->tx_dma_desc,
123 		msgdma_descroffs(read_addr_lo));
124 	csrwr32(upper_32_bits(buffer->dma_addr), priv->tx_dma_desc,
125 		msgdma_descroffs(read_addr_hi));
126 	csrwr32(0, priv->tx_dma_desc, msgdma_descroffs(write_addr_lo));
127 	csrwr32(0, priv->tx_dma_desc, msgdma_descroffs(write_addr_hi));
128 	csrwr32(buffer->len, priv->tx_dma_desc, msgdma_descroffs(len));
129 	csrwr32(0, priv->tx_dma_desc, msgdma_descroffs(burst_seq_num));
130 	csrwr32(MSGDMA_DESC_TX_STRIDE, priv->tx_dma_desc,
131 		msgdma_descroffs(stride));
132 	csrwr32(MSGDMA_DESC_CTL_TX_SINGLE, priv->tx_dma_desc,
133 		msgdma_descroffs(control));
134 	return 0;
135 }
136 
137 u32 msgdma_tx_completions(struct altera_tse_private *priv)
138 {
139 	u32 ready = 0;
140 	u32 inuse;
141 	u32 status;
142 
143 	/* Get number of sent descriptors */
144 	inuse = csrrd32(priv->tx_dma_csr, msgdma_csroffs(rw_fill_level))
145 			& 0xffff;
146 
147 	if (inuse) { /* Tx FIFO is not empty */
148 		ready = max_t(int,
149 			      priv->tx_prod - priv->tx_cons - inuse - 1, 0);
150 	} else {
151 		/* Check for buffered last packet */
152 		status = csrrd32(priv->tx_dma_csr, msgdma_csroffs(status));
153 		if (status & MSGDMA_CSR_STAT_BUSY)
154 			ready = priv->tx_prod - priv->tx_cons - 1;
155 		else
156 			ready = priv->tx_prod - priv->tx_cons;
157 	}
158 	return ready;
159 }
160 
161 /* Put buffer to the mSGDMA RX FIFO
162  */
163 void msgdma_add_rx_desc(struct altera_tse_private *priv,
164 			struct tse_buffer *rxbuffer)
165 {
166 	u32 len = priv->rx_dma_buf_sz;
167 	dma_addr_t dma_addr = rxbuffer->dma_addr;
168 	u32 control = (MSGDMA_DESC_CTL_END_ON_EOP
169 			| MSGDMA_DESC_CTL_END_ON_LEN
170 			| MSGDMA_DESC_CTL_TR_COMP_IRQ
171 			| MSGDMA_DESC_CTL_EARLY_IRQ
172 			| MSGDMA_DESC_CTL_TR_ERR_IRQ
173 			| MSGDMA_DESC_CTL_GO);
174 
175 	csrwr32(0, priv->rx_dma_desc, msgdma_descroffs(read_addr_lo));
176 	csrwr32(0, priv->rx_dma_desc, msgdma_descroffs(read_addr_hi));
177 	csrwr32(lower_32_bits(dma_addr), priv->rx_dma_desc,
178 		msgdma_descroffs(write_addr_lo));
179 	csrwr32(upper_32_bits(dma_addr), priv->rx_dma_desc,
180 		msgdma_descroffs(write_addr_hi));
181 	csrwr32(len, priv->rx_dma_desc, msgdma_descroffs(len));
182 	csrwr32(0, priv->rx_dma_desc, msgdma_descroffs(burst_seq_num));
183 	csrwr32(0x00010001, priv->rx_dma_desc, msgdma_descroffs(stride));
184 	csrwr32(control, priv->rx_dma_desc, msgdma_descroffs(control));
185 }
186 
187 /* status is returned on upper 16 bits,
188  * length is returned in lower 16 bits
189  */
190 u32 msgdma_rx_status(struct altera_tse_private *priv)
191 {
192 	u32 rxstatus = 0;
193 	u32 pktlength;
194 	u32 pktstatus;
195 
196 	if (csrrd32(priv->rx_dma_csr, msgdma_csroffs(resp_fill_level))
197 	    & 0xffff) {
198 		pktlength = csrrd32(priv->rx_dma_resp,
199 				    msgdma_respoffs(bytes_transferred));
200 		pktstatus = csrrd32(priv->rx_dma_resp,
201 				    msgdma_respoffs(status));
202 		rxstatus = pktstatus;
203 		rxstatus = rxstatus << 16;
204 		rxstatus |= (pktlength & 0xffff);
205 	}
206 	return rxstatus;
207 }
208