drivers/net: Remove unnecessary returns from void function()s
[profile/ivi/kernel-x86-ivi.git] / drivers / net / stmmac / dwmac_lib.c
1 /*******************************************************************************
2   Copyright (C) 2007-2009  STMicroelectronics Ltd
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, write to the Free Software Foundation, Inc.,
15   51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
16
17   The full GNU General Public License is included in this distribution in
18   the file called "COPYING".
19
20   Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
21 *******************************************************************************/
22
23 #include <linux/io.h>
24 #include "common.h"
25 #include "dwmac_dma.h"
26
27 #undef DWMAC_DMA_DEBUG
28 #ifdef DWMAC_DMA_DEBUG
29 #define DBG(fmt, args...)  printk(fmt, ## args)
30 #else
31 #define DBG(fmt, args...)  do { } while (0)
32 #endif
33
34 /* CSR1 enables the transmit DMA to check for new descriptor */
35 void dwmac_enable_dma_transmission(unsigned long ioaddr)
36 {
37         writel(1, ioaddr + DMA_XMT_POLL_DEMAND);
38 }
39
40 void dwmac_enable_dma_irq(unsigned long ioaddr)
41 {
42         writel(DMA_INTR_DEFAULT_MASK, ioaddr + DMA_INTR_ENA);
43 }
44
45 void dwmac_disable_dma_irq(unsigned long ioaddr)
46 {
47         writel(0, ioaddr + DMA_INTR_ENA);
48 }
49
50 void dwmac_dma_start_tx(unsigned long ioaddr)
51 {
52         u32 value = readl(ioaddr + DMA_CONTROL);
53         value |= DMA_CONTROL_ST;
54         writel(value, ioaddr + DMA_CONTROL);
55 }
56
57 void dwmac_dma_stop_tx(unsigned long ioaddr)
58 {
59         u32 value = readl(ioaddr + DMA_CONTROL);
60         value &= ~DMA_CONTROL_ST;
61         writel(value, ioaddr + DMA_CONTROL);
62 }
63
64 void dwmac_dma_start_rx(unsigned long ioaddr)
65 {
66         u32 value = readl(ioaddr + DMA_CONTROL);
67         value |= DMA_CONTROL_SR;
68         writel(value, ioaddr + DMA_CONTROL);
69 }
70
71 void dwmac_dma_stop_rx(unsigned long ioaddr)
72 {
73         u32 value = readl(ioaddr + DMA_CONTROL);
74         value &= ~DMA_CONTROL_SR;
75         writel(value, ioaddr + DMA_CONTROL);
76 }
77
78 #ifdef DWMAC_DMA_DEBUG
79 static void show_tx_process_state(unsigned int status)
80 {
81         unsigned int state;
82         state = (status & DMA_STATUS_TS_MASK) >> DMA_STATUS_TS_SHIFT;
83
84         switch (state) {
85         case 0:
86                 pr_info("- TX (Stopped): Reset or Stop command\n");
87                 break;
88         case 1:
89                 pr_info("- TX (Running):Fetching the Tx desc\n");
90                 break;
91         case 2:
92                 pr_info("- TX (Running): Waiting for end of tx\n");
93                 break;
94         case 3:
95                 pr_info("- TX (Running): Reading the data "
96                        "and queuing the data into the Tx buf\n");
97                 break;
98         case 6:
99                 pr_info("- TX (Suspended): Tx Buff Underflow "
100                        "or an unavailable Transmit descriptor\n");
101                 break;
102         case 7:
103                 pr_info("- TX (Running): Closing Tx descriptor\n");
104                 break;
105         default:
106                 break;
107         }
108 }
109
110 static void show_rx_process_state(unsigned int status)
111 {
112         unsigned int state;
113         state = (status & DMA_STATUS_RS_MASK) >> DMA_STATUS_RS_SHIFT;
114
115         switch (state) {
116         case 0:
117                 pr_info("- RX (Stopped): Reset or Stop command\n");
118                 break;
119         case 1:
120                 pr_info("- RX (Running): Fetching the Rx desc\n");
121                 break;
122         case 2:
123                 pr_info("- RX (Running):Checking for end of pkt\n");
124                 break;
125         case 3:
126                 pr_info("- RX (Running): Waiting for Rx pkt\n");
127                 break;
128         case 4:
129                 pr_info("- RX (Suspended): Unavailable Rx buf\n");
130                 break;
131         case 5:
132                 pr_info("- RX (Running): Closing Rx descriptor\n");
133                 break;
134         case 6:
135                 pr_info("- RX(Running): Flushing the current frame"
136                        " from the Rx buf\n");
137                 break;
138         case 7:
139                 pr_info("- RX (Running): Queuing the Rx frame"
140                        " from the Rx buf into memory\n");
141                 break;
142         default:
143                 break;
144         }
145 }
146 #endif
147
148 int dwmac_dma_interrupt(unsigned long ioaddr,
149                         struct stmmac_extra_stats *x)
150 {
151         int ret = 0;
152         /* read the status register (CSR5) */
153         u32 intr_status = readl(ioaddr + DMA_STATUS);
154
155         DBG(INFO, "%s: [CSR5: 0x%08x]\n", __func__, intr_status);
156 #ifdef DWMAC_DMA_DEBUG
157         /* It displays the DMA process states (CSR5 register) */
158         show_tx_process_state(intr_status);
159         show_rx_process_state(intr_status);
160 #endif
161         /* ABNORMAL interrupts */
162         if (unlikely(intr_status & DMA_STATUS_AIS)) {
163                 DBG(INFO, "CSR5[15] DMA ABNORMAL IRQ: ");
164                 if (unlikely(intr_status & DMA_STATUS_UNF)) {
165                         DBG(INFO, "transmit underflow\n");
166                         ret = tx_hard_error_bump_tc;
167                         x->tx_undeflow_irq++;
168                 }
169                 if (unlikely(intr_status & DMA_STATUS_TJT)) {
170                         DBG(INFO, "transmit jabber\n");
171                         x->tx_jabber_irq++;
172                 }
173                 if (unlikely(intr_status & DMA_STATUS_OVF)) {
174                         DBG(INFO, "recv overflow\n");
175                         x->rx_overflow_irq++;
176                 }
177                 if (unlikely(intr_status & DMA_STATUS_RU)) {
178                         DBG(INFO, "receive buffer unavailable\n");
179                         x->rx_buf_unav_irq++;
180                 }
181                 if (unlikely(intr_status & DMA_STATUS_RPS)) {
182                         DBG(INFO, "receive process stopped\n");
183                         x->rx_process_stopped_irq++;
184                 }
185                 if (unlikely(intr_status & DMA_STATUS_RWT)) {
186                         DBG(INFO, "receive watchdog\n");
187                         x->rx_watchdog_irq++;
188                 }
189                 if (unlikely(intr_status & DMA_STATUS_ETI)) {
190                         DBG(INFO, "transmit early interrupt\n");
191                         x->tx_early_irq++;
192                 }
193                 if (unlikely(intr_status & DMA_STATUS_TPS)) {
194                         DBG(INFO, "transmit process stopped\n");
195                         x->tx_process_stopped_irq++;
196                         ret = tx_hard_error;
197                 }
198                 if (unlikely(intr_status & DMA_STATUS_FBI)) {
199                         DBG(INFO, "fatal bus error\n");
200                         x->fatal_bus_error_irq++;
201                         ret = tx_hard_error;
202                 }
203         }
204         /* TX/RX NORMAL interrupts */
205         if (intr_status & DMA_STATUS_NIS) {
206                 x->normal_irq_n++;
207                 if (likely((intr_status & DMA_STATUS_RI) ||
208                          (intr_status & (DMA_STATUS_TI))))
209                                 ret = handle_tx_rx;
210         }
211         /* Optional hardware blocks, interrupts should be disabled */
212         if (unlikely(intr_status &
213                      (DMA_STATUS_GPI | DMA_STATUS_GMI | DMA_STATUS_GLI)))
214                 pr_info("%s: unexpected status %08x\n", __func__, intr_status);
215         /* Clear the interrupt by writing a logic 1 to the CSR5[15-0] */
216         writel((intr_status & 0x1ffff), ioaddr + DMA_STATUS);
217
218         DBG(INFO, "\n\n");
219         return ret;
220 }
221
222 void dwmac_dma_flush_tx_fifo(unsigned long ioaddr)
223 {
224         u32 csr6 = readl(ioaddr + DMA_CONTROL);
225         writel((csr6 | DMA_CONTROL_FTF), ioaddr + DMA_CONTROL);
226
227         do {} while ((readl(ioaddr + DMA_CONTROL) & DMA_CONTROL_FTF));
228 }
229
230 void stmmac_set_mac_addr(unsigned long ioaddr, u8 addr[6],
231                          unsigned int high, unsigned int low)
232 {
233         unsigned long data;
234
235         data = (addr[5] << 8) | addr[4];
236         writel(data, ioaddr + high);
237         data = (addr[3] << 24) | (addr[2] << 16) | (addr[1] << 8) | addr[0];
238         writel(data, ioaddr + low);
239 }
240
241 void stmmac_get_mac_addr(unsigned long ioaddr, unsigned char *addr,
242                          unsigned int high, unsigned int low)
243 {
244         unsigned int hi_addr, lo_addr;
245
246         /* Read the MAC address from the hardware */
247         hi_addr = readl(ioaddr + high);
248         lo_addr = readl(ioaddr + low);
249
250         /* Extract the MAC address from the high and low words */
251         addr[0] = lo_addr & 0xff;
252         addr[1] = (lo_addr >> 8) & 0xff;
253         addr[2] = (lo_addr >> 16) & 0xff;
254         addr[3] = (lo_addr >> 24) & 0xff;
255         addr[4] = hi_addr & 0xff;
256         addr[5] = (hi_addr >> 8) & 0xff;
257 }
258