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