1 /*
2 * Intel Wireless WiMAX Connection 2400m
3 * SDIO RX handling
4 *
5 *
6 * Copyright (C) 2007-2008 Intel Corporation. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * * Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * * Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in
16 * the documentation and/or other materials provided with the
17 * distribution.
18 * * Neither the name of Intel Corporation nor the names of its
19 * contributors may be used to endorse or promote products derived
20 * from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
25 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
26 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
27 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
28 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
32 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 *
34 *
35 * Intel Corporation <linux-wimax@intel.com>
36 * Dirk Brandewie <dirk.j.brandewie@intel.com>
37 * - Initial implementation
38 *
39 *
40 * This handles the RX path on SDIO.
41 *
42 * The SDIO bus driver calls the "irq" routine when data is available.
43 * This is not a traditional interrupt routine since the SDIO bus
44 * driver calls us from its irq thread context. Because of this
45 * sleeping in the SDIO RX IRQ routine is okay.
46 *
47 * From there on, we obtain the size of the data that is available,
48 * allocate an skb, copy it and then pass it to the generic driver's
49 * RX routine [i2400m_rx()].
50 *
51 * ROADMAP
52 *
53 * i2400ms_irq()
54 * i2400ms_rx()
55 * __i2400ms_rx_get_size()
56 * i2400m_is_boot_barker()
57 * i2400m_rx()
58 *
59 * i2400ms_rx_setup()
60 *
61 * i2400ms_rx_release()
62 */
63 #include <linux/workqueue.h>
64 #include <linux/wait.h>
65 #include <linux/skbuff.h>
66 #include <linux/mmc/sdio.h>
67 #include <linux/mmc/sdio_func.h>
68 #include <linux/slab.h>
69 #include "i2400m-sdio.h"
70
71 #define D_SUBMODULE rx
72 #include "sdio-debug-levels.h"
73
74 static const __le32 i2400m_ACK_BARKER[4] = {
75 __constant_cpu_to_le32(I2400M_ACK_BARKER),
76 __constant_cpu_to_le32(I2400M_ACK_BARKER),
77 __constant_cpu_to_le32(I2400M_ACK_BARKER),
78 __constant_cpu_to_le32(I2400M_ACK_BARKER)
79 };
80
81
82 /*
83 * Read and return the amount of bytes available for RX
84 *
85 * The RX size has to be read like this: byte reads of three
86 * sequential locations; then glue'em together.
87 *
88 * sdio_readl() doesn't work.
89 */
__i2400ms_rx_get_size(struct i2400ms * i2400ms)90 static ssize_t __i2400ms_rx_get_size(struct i2400ms *i2400ms)
91 {
92 int ret, cnt, val;
93 ssize_t rx_size;
94 unsigned xfer_size_addr;
95 struct sdio_func *func = i2400ms->func;
96 struct device *dev = &i2400ms->func->dev;
97
98 d_fnstart(7, dev, "(i2400ms %p)\n", i2400ms);
99 xfer_size_addr = I2400MS_INTR_GET_SIZE_ADDR;
100 rx_size = 0;
101 for (cnt = 0; cnt < 3; cnt++) {
102 val = sdio_readb(func, xfer_size_addr + cnt, &ret);
103 if (ret < 0) {
104 dev_err(dev, "RX: Can't read byte %d of RX size from "
105 "0x%08x: %d\n", cnt, xfer_size_addr + cnt, ret);
106 rx_size = ret;
107 goto error_read;
108 }
109 rx_size = rx_size << 8 | (val & 0xff);
110 }
111 d_printf(6, dev, "RX: rx_size is %ld\n", (long) rx_size);
112 error_read:
113 d_fnend(7, dev, "(i2400ms %p) = %ld\n", i2400ms, (long) rx_size);
114 return rx_size;
115 }
116
117
118 /*
119 * Read data from the device (when in normal)
120 *
121 * Allocate an SKB of the right size, read the data in and then
122 * deliver it to the generic layer.
123 *
124 * We also check for a reboot barker. That means the device died and
125 * we have to reboot it.
126 */
127 static
i2400ms_rx(struct i2400ms * i2400ms)128 void i2400ms_rx(struct i2400ms *i2400ms)
129 {
130 int ret;
131 struct sdio_func *func = i2400ms->func;
132 struct device *dev = &func->dev;
133 struct i2400m *i2400m = &i2400ms->i2400m;
134 struct sk_buff *skb;
135 ssize_t rx_size;
136
137 d_fnstart(7, dev, "(i2400ms %p)\n", i2400ms);
138 rx_size = __i2400ms_rx_get_size(i2400ms);
139 if (rx_size < 0) {
140 ret = rx_size;
141 goto error_get_size;
142 }
143 /*
144 * Hardware quirk: make sure to clear the INTR status register
145 * AFTER getting the data transfer size.
146 */
147 sdio_writeb(func, 1, I2400MS_INTR_CLEAR_ADDR, &ret);
148
149 ret = -ENOMEM;
150 skb = alloc_skb(rx_size, GFP_ATOMIC);
151 if (NULL == skb) {
152 dev_err(dev, "RX: unable to alloc skb\n");
153 goto error_alloc_skb;
154 }
155 ret = sdio_memcpy_fromio(func, skb->data,
156 I2400MS_DATA_ADDR, rx_size);
157 if (ret < 0) {
158 dev_err(dev, "RX: SDIO data read failed: %d\n", ret);
159 goto error_memcpy_fromio;
160 }
161
162 rmb(); /* make sure we get boot_mode from dev_reset_handle */
163 if (unlikely(i2400m->boot_mode == 1)) {
164 spin_lock(&i2400m->rx_lock);
165 i2400ms->bm_ack_size = rx_size;
166 spin_unlock(&i2400m->rx_lock);
167 memcpy(i2400m->bm_ack_buf, skb->data, rx_size);
168 wake_up(&i2400ms->bm_wfa_wq);
169 d_printf(5, dev, "RX: SDIO boot mode message\n");
170 kfree_skb(skb);
171 goto out;
172 }
173 ret = -EIO;
174 if (unlikely(rx_size < sizeof(__le32))) {
175 dev_err(dev, "HW BUG? only %zu bytes received\n", rx_size);
176 goto error_bad_size;
177 }
178 if (likely(i2400m_is_d2h_barker(skb->data))) {
179 skb_put(skb, rx_size);
180 i2400m_rx(i2400m, skb);
181 } else if (unlikely(i2400m_is_boot_barker(i2400m,
182 skb->data, rx_size))) {
183 ret = i2400m_dev_reset_handle(i2400m, "device rebooted");
184 dev_err(dev, "RX: SDIO reboot barker\n");
185 kfree_skb(skb);
186 } else {
187 i2400m_unknown_barker(i2400m, skb->data, rx_size);
188 kfree_skb(skb);
189 }
190 out:
191 d_fnend(7, dev, "(i2400ms %p) = void\n", i2400ms);
192 return;
193
194 error_memcpy_fromio:
195 kfree_skb(skb);
196 error_alloc_skb:
197 error_get_size:
198 error_bad_size:
199 d_fnend(7, dev, "(i2400ms %p) = %d\n", i2400ms, ret);
200 }
201
202
203 /*
204 * Process an interrupt from the SDIO card
205 *
206 * FIXME: need to process other events that are not just ready-to-read
207 *
208 * Checks there is data ready and then proceeds to read it.
209 */
210 static
i2400ms_irq(struct sdio_func * func)211 void i2400ms_irq(struct sdio_func *func)
212 {
213 int ret;
214 struct i2400ms *i2400ms = sdio_get_drvdata(func);
215 struct device *dev = &func->dev;
216 int val;
217
218 d_fnstart(6, dev, "(i2400ms %p)\n", i2400ms);
219 val = sdio_readb(func, I2400MS_INTR_STATUS_ADDR, &ret);
220 if (ret < 0) {
221 dev_err(dev, "RX: Can't read interrupt status: %d\n", ret);
222 goto error_no_irq;
223 }
224 if (!val) {
225 dev_err(dev, "RX: BUG? got IRQ but no interrupt ready?\n");
226 goto error_no_irq;
227 }
228 i2400ms_rx(i2400ms);
229 error_no_irq:
230 d_fnend(6, dev, "(i2400ms %p) = void\n", i2400ms);
231 }
232
233
234 /*
235 * Setup SDIO RX
236 *
237 * Hooks up the IRQ handler and then enables IRQs.
238 */
i2400ms_rx_setup(struct i2400ms * i2400ms)239 int i2400ms_rx_setup(struct i2400ms *i2400ms)
240 {
241 int result;
242 struct sdio_func *func = i2400ms->func;
243 struct device *dev = &func->dev;
244 struct i2400m *i2400m = &i2400ms->i2400m;
245
246 d_fnstart(5, dev, "(i2400ms %p)\n", i2400ms);
247
248 init_waitqueue_head(&i2400ms->bm_wfa_wq);
249 spin_lock(&i2400m->rx_lock);
250 i2400ms->bm_wait_result = -EINPROGRESS;
251 /*
252 * Before we are about to enable the RX interrupt, make sure
253 * bm_ack_size is cleared to -EINPROGRESS which indicates
254 * no RX interrupt happened yet or the previous interrupt
255 * has been handled, we are ready to take the new interrupt
256 */
257 i2400ms->bm_ack_size = -EINPROGRESS;
258 spin_unlock(&i2400m->rx_lock);
259
260 sdio_claim_host(func);
261 result = sdio_claim_irq(func, i2400ms_irq);
262 if (result < 0) {
263 dev_err(dev, "Cannot claim IRQ: %d\n", result);
264 goto error_irq_claim;
265 }
266 result = 0;
267 sdio_writeb(func, 1, I2400MS_INTR_ENABLE_ADDR, &result);
268 if (result < 0) {
269 sdio_release_irq(func);
270 dev_err(dev, "Failed to enable interrupts %d\n", result);
271 }
272 error_irq_claim:
273 sdio_release_host(func);
274 d_fnend(5, dev, "(i2400ms %p) = %d\n", i2400ms, result);
275 return result;
276 }
277
278
279 /*
280 * Tear down SDIO RX
281 *
282 * Disables IRQs in the device and removes the IRQ handler.
283 */
i2400ms_rx_release(struct i2400ms * i2400ms)284 void i2400ms_rx_release(struct i2400ms *i2400ms)
285 {
286 int result;
287 struct sdio_func *func = i2400ms->func;
288 struct device *dev = &func->dev;
289 struct i2400m *i2400m = &i2400ms->i2400m;
290
291 d_fnstart(5, dev, "(i2400ms %p)\n", i2400ms);
292 spin_lock(&i2400m->rx_lock);
293 i2400ms->bm_ack_size = -EINTR;
294 spin_unlock(&i2400m->rx_lock);
295 wake_up_all(&i2400ms->bm_wfa_wq);
296 sdio_claim_host(func);
297 sdio_writeb(func, 0, I2400MS_INTR_ENABLE_ADDR, &result);
298 sdio_release_irq(func);
299 sdio_release_host(func);
300 d_fnend(5, dev, "(i2400ms %p) = %d\n", i2400ms, result);
301 }
302