drivers/net/wimax/i2400m/sdio-rx.c

   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  */
  90 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
 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         return;
 201 }
 202
 203
 204 /*
 205  * Process an interrupt from the SDIO card
 206  *
 207  * FIXME: need to process other events that are not just ready-to-read
 208  *
 209  * Checks there is data ready and then proceeds to read it.
 210  */
 211 static
 212 void i2400ms_irq(struct sdio_func *func)
 213 {
 214         int ret;
 215         struct i2400ms *i2400ms = sdio_get_drvdata(func);
 216         struct device *dev = &func->dev;
 217         int val;
 218
 219         d_fnstart(6, dev, "(i2400ms %p)\n", i2400ms);
 220         val = sdio_readb(func, I2400MS_INTR_STATUS_ADDR, &ret);
 221         if (ret < 0) {
 222                 dev_err(dev, "RX: Can't read interrupt status: %d\n", ret);
 223                 goto error_no_irq;
 224         }
 225         if (!val) {
 226                 dev_err(dev, "RX: BUG? got IRQ but no interrupt ready?\n");
 227                 goto error_no_irq;
 228         }
 229         i2400ms_rx(i2400ms);
 230 error_no_irq:
 231         d_fnend(6, dev, "(i2400ms %p) = void\n", i2400ms);
 232         return;
 233 }
 234
 235
 236 /*
 237  * Setup SDIO RX
 238  *
 239  * Hooks up the IRQ handler and then enables IRQs.
 240  */
 241 int i2400ms_rx_setup(struct i2400ms *i2400ms)
 242 {
 243         int result;
 244         struct sdio_func *func = i2400ms->func;
 245         struct device *dev = &func->dev;
 246         struct i2400m *i2400m = &i2400ms->i2400m;
 247
 248         d_fnstart(5, dev, "(i2400ms %p)\n", i2400ms);
 249
 250         init_waitqueue_head(&i2400ms->bm_wfa_wq);
 251         spin_lock(&i2400m->rx_lock);
 252         i2400ms->bm_wait_result = -EINPROGRESS;
 253         /*
 254          * Before we are about to enable the RX interrupt, make sure
 255          * bm_ack_size is cleared to -EINPROGRESS which indicates
 256          * no RX interrupt happened yet or the previous interrupt
 257          * has been handled, we are ready to take the new interrupt
 258          */
 259         i2400ms->bm_ack_size = -EINPROGRESS;
 260         spin_unlock(&i2400m->rx_lock);
 261
 262         sdio_claim_host(func);
 263         result = sdio_claim_irq(func, i2400ms_irq);
 264         if (result < 0) {
 265                 dev_err(dev, "Cannot claim IRQ: %d\n", result);
 266                 goto error_irq_claim;
 267         }
 268         result = 0;
 269         sdio_writeb(func, 1, I2400MS_INTR_ENABLE_ADDR, &result);
 270         if (result < 0) {
 271                 sdio_release_irq(func);
 272                 dev_err(dev, "Failed to enable interrupts %d\n", result);
 273         }
 274 error_irq_claim:
 275         sdio_release_host(func);
 276         d_fnend(5, dev, "(i2400ms %p) = %d\n", i2400ms, result);
 277         return result;
 278 }
 279
 280
 281 /*
 282  * Tear down SDIO RX
 283  *
 284  * Disables IRQs in the device and removes the IRQ handler.
 285  */
 286 void i2400ms_rx_release(struct i2400ms *i2400ms)
 287 {
 288         int result;
 289         struct sdio_func *func = i2400ms->func;
 290         struct device *dev = &func->dev;
 291         struct i2400m *i2400m = &i2400ms->i2400m;
 292
 293         d_fnstart(5, dev, "(i2400ms %p)\n", i2400ms);
 294         spin_lock(&i2400m->rx_lock);
 295         i2400ms->bm_ack_size = -EINTR;
 296         spin_unlock(&i2400m->rx_lock);
 297         wake_up_all(&i2400ms->bm_wfa_wq);
 298         sdio_claim_host(func);
 299         sdio_writeb(func, 0, I2400MS_INTR_ENABLE_ADDR, &result);
 300         sdio_release_irq(func);
 301         sdio_release_host(func);
 302         d_fnend(5, dev, "(i2400ms %p) = %d\n", i2400ms, result);
 303 }