target/linux/generic/backport-5.4/806-v5.8-i2c-pxa-re-arrange-functions-to-flow-better.patch

   1 From: Russell King <rmk+kernel@armlinux.org.uk>
   2 Bcc: linux@mail.armlinux.org.uk
   3 Cc: linux-i2c@vger.kernel.org
   4 Subject: [PATCH 04/17] i2c: pxa: re-arrange functions to flow better
   5 MIME-Version: 1.0
   6 Content-Disposition: inline
   7 Content-Transfer-Encoding: 8bit
   8 Content-Type: text/plain; charset="utf-8"
   9
  10 Re-arrange the PXA I2C code to avoid forward declarations, and keep
  11 similar functionality (e.g. the non-IRQ mode support) together. This
  12 improves code readability.
  13
  14 Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
  15 ---
  16  drivers/i2c/busses/i2c-pxa.c | 325 +++++++++++++++++------------------
  17  1 file changed, 162 insertions(+), 163 deletions(-)
  18
  19 --- a/drivers/i2c/busses/i2c-pxa.c
  20 +++ b/drivers/i2c/busses/i2c-pxa.c
  21 @@ -327,7 +327,6 @@ static void i2c_pxa_scream_blue_murder(s
  22  #endif /* ifdef DEBUG / else */
  23
  24  static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret);
  25 -static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id);
  26
  27  static inline int i2c_pxa_is_slavemode(struct pxa_i2c *i2c)
  28  {
  29 @@ -700,34 +699,6 @@ static inline void i2c_pxa_stop_message(
  30         writel(icr, _ICR(i2c));
  31  }
  32
  33 -static int i2c_pxa_pio_set_master(struct pxa_i2c *i2c)
  34 -{
  35 -       /* make timeout the same as for interrupt based functions */
  36 -       long timeout = 2 * DEF_TIMEOUT;
  37 -
  38 -       /*
  39 -        * Wait for the bus to become free.
  40 -        */
  41 -       while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
  42 -               udelay(1000);
  43 -               show_state(i2c);
  44 -       }
  45 -
  46 -       if (timeout < 0) {
  47 -               show_state(i2c);
  48 -               dev_err(&i2c->adap.dev,
  49 -                       "i2c_pxa: timeout waiting for bus free\n");
  50 -               return I2C_RETRY;
  51 -       }
  52 -
  53 -       /*
  54 -        * Set master mode.
  55 -        */
  56 -       writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
  57 -
  58 -       return 0;
  59 -}
  60 -
  61  /*
  62   * PXA I2C send master code
  63   * 1. Load master code to IDBR and send it.
  64 @@ -756,140 +727,6 @@ static int i2c_pxa_send_mastercode(struc
  65         return (timeout == 0) ? I2C_RETRY : 0;
  66  }
  67
  68 -static int i2c_pxa_do_pio_xfer(struct pxa_i2c *i2c,
  69 -                              struct i2c_msg *msg, int num)
  70 -{
  71 -       unsigned long timeout = 500000; /* 5 seconds */
  72 -       int ret = 0;
  73 -
  74 -       ret = i2c_pxa_pio_set_master(i2c);
  75 -       if (ret)
  76 -               goto out;
  77 -
  78 -       i2c->msg = msg;
  79 -       i2c->msg_num = num;
  80 -       i2c->msg_idx = 0;
  81 -       i2c->msg_ptr = 0;
  82 -       i2c->irqlogidx = 0;
  83 -
  84 -       i2c_pxa_start_message(i2c);
  85 -
  86 -       while (i2c->msg_num > 0 && --timeout) {
  87 -               i2c_pxa_handler(0, i2c);
  88 -               udelay(10);
  89 -       }
  90 -
  91 -       i2c_pxa_stop_message(i2c);
  92 -
  93 -       /*
  94 -        * We place the return code in i2c->msg_idx.
  95 -        */
  96 -       ret = i2c->msg_idx;
  97 -
  98 -out:
  99 -       if (timeout == 0) {
 100 -               i2c_pxa_scream_blue_murder(i2c, "timeout");
 101 -               ret = I2C_RETRY;
 102 -       }
 103 -
 104 -       return ret;
 105 -}
 106 -
 107 -/*
 108 - * We are protected by the adapter bus mutex.
 109 - */
 110 -static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
 111 -{
 112 -       long timeout;
 113 -       int ret;
 114 -
 115 -       /*
 116 -        * Wait for the bus to become free.
 117 -        */
 118 -       ret = i2c_pxa_wait_bus_not_busy(i2c);
 119 -       if (ret) {
 120 -               dev_err(&i2c->adap.dev, "i2c_pxa: timeout waiting for bus free\n");
 121 -               goto out;
 122 -       }
 123 -
 124 -       /*
 125 -        * Set master mode.
 126 -        */
 127 -       ret = i2c_pxa_set_master(i2c);
 128 -       if (ret) {
 129 -               dev_err(&i2c->adap.dev, "i2c_pxa_set_master: error %d\n", ret);
 130 -               goto out;
 131 -       }
 132 -
 133 -       if (i2c->high_mode) {
 134 -               ret = i2c_pxa_send_mastercode(i2c);
 135 -               if (ret) {
 136 -                       dev_err(&i2c->adap.dev, "i2c_pxa_send_mastercode timeout\n");
 137 -                       goto out;
 138 -                       }
 139 -       }
 140 -
 141 -       spin_lock_irq(&i2c->lock);
 142 -
 143 -       i2c->msg = msg;
 144 -       i2c->msg_num = num;
 145 -       i2c->msg_idx = 0;
 146 -       i2c->msg_ptr = 0;
 147 -       i2c->irqlogidx = 0;
 148 -
 149 -       i2c_pxa_start_message(i2c);
 150 -
 151 -       spin_unlock_irq(&i2c->lock);
 152 -
 153 -       /*
 154 -        * The rest of the processing occurs in the interrupt handler.
 155 -        */
 156 -       timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
 157 -       i2c_pxa_stop_message(i2c);
 158 -
 159 -       /*
 160 -        * We place the return code in i2c->msg_idx.
 161 -        */
 162 -       ret = i2c->msg_idx;
 163 -
 164 -       if (!timeout && i2c->msg_num) {
 165 -               i2c_pxa_scream_blue_murder(i2c, "timeout");
 166 -               ret = I2C_RETRY;
 167 -       }
 168 -
 169 - out:
 170 -       return ret;
 171 -}
 172 -
 173 -static int i2c_pxa_pio_xfer(struct i2c_adapter *adap,
 174 -                           struct i2c_msg msgs[], int num)
 175 -{
 176 -       struct pxa_i2c *i2c = adap->algo_data;
 177 -       int ret, i;
 178 -
 179 -       /* If the I2C controller is disabled we need to reset it
 180 -         (probably due to a suspend/resume destroying state). We do
 181 -         this here as we can then avoid worrying about resuming the
 182 -         controller before its users. */
 183 -       if (!(readl(_ICR(i2c)) & ICR_IUE))
 184 -               i2c_pxa_reset(i2c);
 185 -
 186 -       for (i = adap->retries; i >= 0; i--) {
 187 -               ret = i2c_pxa_do_pio_xfer(i2c, msgs, num);
 188 -               if (ret != I2C_RETRY)
 189 -                       goto out;
 190 -
 191 -               if (i2c_debug)
 192 -                       dev_dbg(&adap->dev, "Retrying transmission\n");
 193 -               udelay(100);
 194 -       }
 195 -       i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
 196 -       ret = -EREMOTEIO;
 197 - out:
 198 -       i2c_pxa_set_slave(i2c, ret);
 199 -       return ret;
 200 -}
 201 -
 202  /*
 203   * i2c_pxa_master_complete - complete the message and wake up.
 204   */
 205 @@ -1096,6 +933,71 @@ static irqreturn_t i2c_pxa_handler(int t
 206         return IRQ_HANDLED;
 207  }
 208
 209 +/*
 210 + * We are protected by the adapter bus mutex.
 211 + */
 212 +static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
 213 +{
 214 +       long timeout;
 215 +       int ret;
 216 +
 217 +       /*
 218 +        * Wait for the bus to become free.
 219 +        */
 220 +       ret = i2c_pxa_wait_bus_not_busy(i2c);
 221 +       if (ret) {
 222 +               dev_err(&i2c->adap.dev, "i2c_pxa: timeout waiting for bus free\n");
 223 +               goto out;
 224 +       }
 225 +
 226 +       /*
 227 +        * Set master mode.
 228 +        */
 229 +       ret = i2c_pxa_set_master(i2c);
 230 +       if (ret) {
 231 +               dev_err(&i2c->adap.dev, "i2c_pxa_set_master: error %d\n", ret);
 232 +               goto out;
 233 +       }
 234 +
 235 +       if (i2c->high_mode) {
 236 +               ret = i2c_pxa_send_mastercode(i2c);
 237 +               if (ret) {
 238 +                       dev_err(&i2c->adap.dev, "i2c_pxa_send_mastercode timeout\n");
 239 +                       goto out;
 240 +                       }
 241 +       }
 242 +
 243 +       spin_lock_irq(&i2c->lock);
 244 +
 245 +       i2c->msg = msg;
 246 +       i2c->msg_num = num;
 247 +       i2c->msg_idx = 0;
 248 +       i2c->msg_ptr = 0;
 249 +       i2c->irqlogidx = 0;
 250 +
 251 +       i2c_pxa_start_message(i2c);
 252 +
 253 +       spin_unlock_irq(&i2c->lock);
 254 +
 255 +       /*
 256 +        * The rest of the processing occurs in the interrupt handler.
 257 +        */
 258 +       timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
 259 +       i2c_pxa_stop_message(i2c);
 260 +
 261 +       /*
 262 +        * We place the return code in i2c->msg_idx.
 263 +        */
 264 +       ret = i2c->msg_idx;
 265 +
 266 +       if (!timeout && i2c->msg_num) {
 267 +               i2c_pxa_scream_blue_murder(i2c, "timeout");
 268 +               ret = I2C_RETRY;
 269 +       }
 270 +
 271 + out:
 272 +       return ret;
 273 +}
 274
 275  static int i2c_pxa_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 276  {
 277 @@ -1129,6 +1031,103 @@ static const struct i2c_algorithm i2c_px
 278         .functionality  = i2c_pxa_functionality,
 279  };
 280
 281 +/* Non-interrupt mode support */
 282 +static int i2c_pxa_pio_set_master(struct pxa_i2c *i2c)
 283 +{
 284 +       /* make timeout the same as for interrupt based functions */
 285 +       long timeout = 2 * DEF_TIMEOUT;
 286 +
 287 +       /*
 288 +        * Wait for the bus to become free.
 289 +        */
 290 +       while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
 291 +               udelay(1000);
 292 +               show_state(i2c);
 293 +       }
 294 +
 295 +       if (timeout < 0) {
 296 +               show_state(i2c);
 297 +               dev_err(&i2c->adap.dev,
 298 +                       "i2c_pxa: timeout waiting for bus free\n");
 299 +               return I2C_RETRY;
 300 +       }
 301 +
 302 +       /*
 303 +        * Set master mode.
 304 +        */
 305 +       writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
 306 +
 307 +       return 0;
 308 +}
 309 +
 310 +static int i2c_pxa_do_pio_xfer(struct pxa_i2c *i2c,
 311 +                              struct i2c_msg *msg, int num)
 312 +{
 313 +       unsigned long timeout = 500000; /* 5 seconds */
 314 +       int ret = 0;
 315 +
 316 +       ret = i2c_pxa_pio_set_master(i2c);
 317 +       if (ret)
 318 +               goto out;
 319 +
 320 +       i2c->msg = msg;
 321 +       i2c->msg_num = num;
 322 +       i2c->msg_idx = 0;
 323 +       i2c->msg_ptr = 0;
 324 +       i2c->irqlogidx = 0;
 325 +
 326 +       i2c_pxa_start_message(i2c);
 327 +
 328 +       while (i2c->msg_num > 0 && --timeout) {
 329 +               i2c_pxa_handler(0, i2c);
 330 +               udelay(10);
 331 +       }
 332 +
 333 +       i2c_pxa_stop_message(i2c);
 334 +
 335 +       /*
 336 +        * We place the return code in i2c->msg_idx.
 337 +        */
 338 +       ret = i2c->msg_idx;
 339 +
 340 +out:
 341 +       if (timeout == 0) {
 342 +               i2c_pxa_scream_blue_murder(i2c, "timeout");
 343 +               ret = I2C_RETRY;
 344 +       }
 345 +
 346 +       return ret;
 347 +}
 348 +
 349 +static int i2c_pxa_pio_xfer(struct i2c_adapter *adap,
 350 +                           struct i2c_msg msgs[], int num)
 351 +{
 352 +       struct pxa_i2c *i2c = adap->algo_data;
 353 +       int ret, i;
 354 +
 355 +       /* If the I2C controller is disabled we need to reset it
 356 +         (probably due to a suspend/resume destroying state). We do
 357 +         this here as we can then avoid worrying about resuming the
 358 +         controller before its users. */
 359 +       if (!(readl(_ICR(i2c)) & ICR_IUE))
 360 +               i2c_pxa_reset(i2c);
 361 +
 362 +       for (i = adap->retries; i >= 0; i--) {
 363 +               ret = i2c_pxa_do_pio_xfer(i2c, msgs, num);
 364 +               if (ret != I2C_RETRY)
 365 +                       goto out;
 366 +
 367 +               if (i2c_debug)
 368 +                       dev_dbg(&adap->dev, "Retrying transmission\n");
 369 +               udelay(100);
 370 +       }
 371 +       i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
 372 +       ret = -EREMOTEIO;
 373 + out:
 374 +       i2c_pxa_set_slave(i2c, ret);
 375 +       return ret;
 376 +}
 377 +
 378  static const struct i2c_algorithm i2c_pxa_pio_algorithm = {
 379         .master_xfer    = i2c_pxa_pio_xfer,
 380         .functionality  = i2c_pxa_functionality,