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 */
24int msgdma_initialize(struct altera_tse_private *priv)
25{
26	return 0;
27}
28
29void msgdma_uninitialize(struct altera_tse_private *priv)
30{
31}
32
33void msgdma_start_rxdma(struct altera_tse_private *priv)
34{
35}
36
37void 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
85void 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
91void 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
97void 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
103void 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
109void msgdma_clear_rxirq(struct altera_tse_private *priv)
110{
111	csrwr32(MSGDMA_CSR_STAT_IRQ, priv->rx_dma_csr, msgdma_csroffs(status));
112}
113
114void 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 */
120int 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
137u32 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 = priv->tx_prod - priv->tx_cons - inuse - 1;
149	} else {
150		/* Check for buffered last packet */
151		status = csrrd32(priv->tx_dma_csr, msgdma_csroffs(status));
152		if (status & MSGDMA_CSR_STAT_BUSY)
153			ready = priv->tx_prod - priv->tx_cons - 1;
154		else
155			ready = priv->tx_prod - priv->tx_cons;
156	}
157	return ready;
158}
159
160/* Put buffer to the mSGDMA RX FIFO
161 */
162void msgdma_add_rx_desc(struct altera_tse_private *priv,
163			struct tse_buffer *rxbuffer)
164{
165	u32 len = priv->rx_dma_buf_sz;
166	dma_addr_t dma_addr = rxbuffer->dma_addr;
167	u32 control = (MSGDMA_DESC_CTL_END_ON_EOP
168			| MSGDMA_DESC_CTL_END_ON_LEN
169			| MSGDMA_DESC_CTL_TR_COMP_IRQ
170			| MSGDMA_DESC_CTL_EARLY_IRQ
171			| MSGDMA_DESC_CTL_TR_ERR_IRQ
172			| MSGDMA_DESC_CTL_GO);
173
174	csrwr32(0, priv->rx_dma_desc, msgdma_descroffs(read_addr_lo));
175	csrwr32(0, priv->rx_dma_desc, msgdma_descroffs(read_addr_hi));
176	csrwr32(lower_32_bits(dma_addr), priv->rx_dma_desc,
177		msgdma_descroffs(write_addr_lo));
178	csrwr32(upper_32_bits(dma_addr), priv->rx_dma_desc,
179		msgdma_descroffs(write_addr_hi));
180	csrwr32(len, priv->rx_dma_desc, msgdma_descroffs(len));
181	csrwr32(0, priv->rx_dma_desc, msgdma_descroffs(burst_seq_num));
182	csrwr32(0x00010001, priv->rx_dma_desc, msgdma_descroffs(stride));
183	csrwr32(control, priv->rx_dma_desc, msgdma_descroffs(control));
184}
185
186/* status is returned on upper 16 bits,
187 * length is returned in lower 16 bits
188 */
189u32 msgdma_rx_status(struct altera_tse_private *priv)
190{
191	u32 rxstatus = 0;
192	u32 pktlength;
193	u32 pktstatus;
194
195	if (csrrd32(priv->rx_dma_csr, msgdma_csroffs(resp_fill_level))
196	    & 0xffff) {
197		pktlength = csrrd32(priv->rx_dma_resp,
198				    msgdma_respoffs(bytes_transferred));
199		pktstatus = csrrd32(priv->rx_dma_resp,
200				    msgdma_respoffs(status));
201		rxstatus = pktstatus;
202		rxstatus = rxstatus << 16;
203		rxstatus |= (pktlength & 0xffff);
204	}
205	return rxstatus;
206}
207