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_rx()
  57  *
  58  * i2400ms_rx_setup()
  59  *
  60  * i2400ms_rx_release()
  61  */
  62 #include <linux/workqueue.h>
  63 #include <linux/wait.h>
  64 #include <linux/skbuff.h>
  65 #include <linux/mmc/sdio.h>
  66 #include <linux/mmc/sdio_func.h>
  67 #include "i2400m-sdio.h"
  68
  69 #define D_SUBMODULE rx
  70 #include "sdio-debug-levels.h"
  71
  72 static const __le32 i2400m_ACK_BARKER[4] = {
  73         __constant_cpu_to_le32(I2400M_ACK_BARKER),
  74         __constant_cpu_to_le32(I2400M_ACK_BARKER),
  75         __constant_cpu_to_le32(I2400M_ACK_BARKER),
  76         __constant_cpu_to_le32(I2400M_ACK_BARKER)
  77 };
  78
  79
  80 /*
  81  * Read and return the amount of bytes available for RX
  82  *
  83  * The RX size has to be read like this: byte reads of three
  84  * sequential locations; then glue'em together.
  85  *
  86  * sdio_readl() doesn't work.
  87  */
  88 ssize_t __i2400ms_rx_get_size(struct i2400ms *i2400ms)
  89 {
  90         int ret, cnt, val;
  91         ssize_t rx_size;
  92         unsigned xfer_size_addr;
  93         struct sdio_func *func = i2400ms->func;
  94         struct device *dev = &i2400ms->func->dev;
  95
  96         d_fnstart(7, dev, "(i2400ms %p)\n", i2400ms);
  97         xfer_size_addr = I2400MS_INTR_GET_SIZE_ADDR;
  98         rx_size = 0;
  99         for (cnt = 0; cnt < 3; cnt++) {
 100                 val = sdio_readb(func, xfer_size_addr + cnt, &ret);
 101                 if (ret < 0) {
 102                         dev_err(dev, "RX: Can't read byte %d of RX size from "
 103                                 "0x%08x: %d\n", cnt, xfer_size_addr + cnt, ret);
 104                         rx_size = ret;
 105                         goto error_read;
 106                 }
 107                 rx_size = rx_size << 8 | (val & 0xff);
 108         }
 109         d_printf(6, dev, "RX: rx_size is %ld\n", (long) rx_size);
 110 error_read:
 111         d_fnend(7, dev, "(i2400ms %p) = %ld\n", i2400ms, (long) rx_size);
 112         return rx_size;
 113 }
 114
 115
 116 /*
 117  * Read data from the device (when in normal)
 118  *
 119  * Allocate an SKB of the right size, read the data in and then
 120  * deliver it to the generic layer.
 121  *
 122  * We also check for a reboot barker. That means the device died and
 123  * we have to reboot it.
 124  */
 125 static
 126 void i2400ms_rx(struct i2400ms *i2400ms)
 127 {
 128         int ret;
 129         struct sdio_func *func = i2400ms->func;
 130         struct device *dev = &func->dev;
 131         struct i2400m *i2400m = &i2400ms->i2400m;
 132         struct sk_buff *skb;
 133         ssize_t rx_size;
 134
 135         d_fnstart(7, dev, "(i2400ms %p)\n", i2400ms);
 136         rx_size = __i2400ms_rx_get_size(i2400ms);
 137         if (rx_size < 0) {
 138                 ret = rx_size;
 139                 goto error_get_size;
 140         }
 141
 142         ret = -ENOMEM;
 143         skb = alloc_skb(rx_size, GFP_ATOMIC);
 144         if (NULL == skb) {
 145                 dev_err(dev, "RX: unable to alloc skb\n");
 146                 goto error_alloc_skb;
 147         }
 148         ret = sdio_memcpy_fromio(func, skb->data,
 149                                  I2400MS_DATA_ADDR, rx_size);
 150         if (ret < 0) {
 151                 dev_err(dev, "RX: SDIO data read failed: %d\n", ret);
 152                 goto error_memcpy_fromio;
 153         }
 154
 155         rmb();  /* make sure we get boot_mode from dev_reset_handle */
 156         if (i2400m->boot_mode == 1) {
 157                 spin_lock(&i2400m->rx_lock);
 158                 i2400ms->bm_ack_size = rx_size;
 159                 spin_unlock(&i2400m->rx_lock);
 160                 memcpy(i2400m->bm_ack_buf, skb->data, rx_size);
 161                 wake_up(&i2400ms->bm_wfa_wq);
 162                 dev_err(dev, "RX: SDIO boot mode message\n");
 163                 kfree_skb(skb);
 164         } else if (unlikely(!memcmp(skb->data, i2400m_NBOOT_BARKER,
 165                                     sizeof(i2400m_NBOOT_BARKER))
 166                             || !memcmp(skb->data, i2400m_SBOOT_BARKER,
 167                                        sizeof(i2400m_SBOOT_BARKER)))) {
 168                 ret = i2400m_dev_reset_handle(i2400m);
 169                 dev_err(dev, "RX: SDIO reboot barker\n");
 170                 kfree_skb(skb);
 171         } else {
 172                 skb_put(skb, rx_size);
 173                 i2400m_rx(i2400m, skb);
 174         }
 175         d_fnend(7, dev, "(i2400ms %p) = void\n", i2400ms);
 176         return;
 177
 178 error_memcpy_fromio:
 179         kfree_skb(skb);
 180 error_alloc_skb:
 181 error_get_size:
 182         d_fnend(7, dev, "(i2400ms %p) = %d\n", i2400ms, ret);
 183         return;
 184 }
 185
 186
 187 /*
 188  * Process an interrupt from the SDIO card
 189  *
 190  * FIXME: need to process other events that are not just ready-to-read
 191  *
 192  * Checks there is data ready and then proceeds to read it.
 193  */
 194 static
 195 void i2400ms_irq(struct sdio_func *func)
 196 {
 197         int ret;
 198         struct i2400ms *i2400ms = sdio_get_drvdata(func);
 199         struct device *dev = &func->dev;
 200         int val;
 201
 202         d_fnstart(6, dev, "(i2400ms %p)\n", i2400ms);
 203         val = sdio_readb(func, I2400MS_INTR_STATUS_ADDR, &ret);
 204         if (ret < 0) {
 205                 dev_err(dev, "RX: Can't read interrupt status: %d\n", ret);
 206                 goto error_no_irq;
 207         }
 208         if (!val) {
 209                 dev_err(dev, "RX: BUG? got IRQ but no interrupt ready?\n");
 210                 goto error_no_irq;
 211         }
 212         sdio_writeb(func, 1, I2400MS_INTR_CLEAR_ADDR, &ret);
 213         i2400ms_rx(i2400ms);
 214 error_no_irq:
 215         d_fnend(6, dev, "(i2400ms %p) = void\n", i2400ms);
 216         return;
 217 }
 218
 219
 220 /*
 221  * Setup SDIO RX
 222  *
 223  * Hooks up the IRQ handler and then enables IRQs.
 224  */
 225 int i2400ms_rx_setup(struct i2400ms *i2400ms)
 226 {
 227         int result;
 228         struct sdio_func *func = i2400ms->func;
 229         struct device *dev = &func->dev;
 230         struct i2400m *i2400m = &i2400ms->i2400m;
 231
 232         d_fnstart(5, dev, "(i2400ms %p)\n", i2400ms);
 233
 234         init_waitqueue_head(&i2400ms->bm_wfa_wq);
 235         spin_lock(&i2400m->rx_lock);
 236         i2400ms->bm_wait_result = -EINPROGRESS;
 237         spin_unlock(&i2400m->rx_lock);
 238
 239         sdio_claim_host(func);
 240         result = sdio_claim_irq(func, i2400ms_irq);
 241         if (result < 0) {
 242                 dev_err(dev, "Cannot claim IRQ: %d\n", result);
 243                 goto error_irq_claim;
 244         }
 245         result = 0;
 246         sdio_writeb(func, 1, I2400MS_INTR_ENABLE_ADDR, &result);
 247         if (result < 0) {
 248                 sdio_release_irq(func);
 249                 dev_err(dev, "Failed to enable interrupts %d\n", result);
 250         }
 251 error_irq_claim:
 252         sdio_release_host(func);
 253         d_fnend(5, dev, "(i2400ms %p) = %d\n", i2400ms, result);
 254         return result;
 255 }
 256
 257
 258 /*
 259  * Tear down SDIO RX
 260  *
 261  * Disables IRQs in the device and removes the IRQ handler.
 262  */
 263 void i2400ms_rx_release(struct i2400ms *i2400ms)
 264 {
 265         int result;
 266         struct sdio_func *func = i2400ms->func;
 267         struct device *dev = &func->dev;
 268         struct i2400m *i2400m = &i2400ms->i2400m;
 269
 270         d_fnstart(5, dev, "(i2400ms %p)\n", i2400ms);
 271         spin_lock(&i2400m->rx_lock);
 272         i2400ms->bm_ack_size = -EINTR;
 273         spin_unlock(&i2400m->rx_lock);
 274         wake_up_all(&i2400ms->bm_wfa_wq);
 275         sdio_claim_host(func);
 276         sdio_writeb(func, 0, I2400MS_INTR_ENABLE_ADDR, &result);
 277         sdio_release_irq(func);
 278         sdio_release_host(func);
 279         d_fnend(5, dev, "(i2400ms %p) = %d\n", i2400ms, result);
 280 }