bertos/cpu/arm/drv/i2c_lpc2.c

   1 /**
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   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
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  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
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  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19  *
  20  * As a special exception, you may use this file as part of a free software
  21  * library without restriction.  Specifically, if other files instantiate
  22  * templates or use macros or inline functions from this file, or you compile
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  24  * file does not by itself cause the resulting executable to be covered by
  25  * the GNU General Public License.  This exception does not however
  26  * invalidate any other reasons why the executable file might be covered by
  27  * the GNU General Public License.
  28  *
  29  * Copyright 2010 Develer S.r.l. (http://www.develer.com/)
  30  *
  31  * -->
  32  *
  33  * \brief Driver for the LPC23xx I2C (implementation)
  34  *
  35  */
  36
  37 #include "cfg/cfg_i2c.h"
  38
  39 #define LOG_LEVEL  I2C_LOG_LEVEL
  40 #define LOG_FORMAT I2C_LOG_FORMAT
  41
  42 #include <cfg/log.h>
  43
  44 #include <cfg/debug.h>
  45 #include <cfg/macros.h> // BV()
  46 #include <cfg/module.h>
  47
  48 #include <cpu/detect.h>
  49 #include <cpu/irq.h>
  50
  51 #include <drv/timer.h>
  52 #include <drv/i2c.h>
  53 #include <drv/vic_lpc2.h> /* vic_handler_t */
  54
  55 #include <io/lpc23xx.h>
  56
  57 #include <stdarg.h>
  58
  59
  60 struct I2cHardware
  61 {
  62         int dev;
  63 };
  64
  65 /*
  66  *
  67  */
  68 #if 1
  69         /* I2C 0 */
  70         #define I2C_PCONP                    PCONP_PCI2C0
  71         #define I2C_CONSET                   I20CONSET
  72         #define I2C_CONCLR                   I20CONCLR
  73         #define I2C_SCLH                     I20SCLH
  74         #define I2C_SCLL                     I20SCLL
  75         #define I2C_STAT                     I20STAT
  76         #define I2C_DAT                      I20DAT
  77         #define I2C_PINSEL_PORT              PINSEL1
  78         #define I2C_PINSEL                   I2C0_PINSEL
  79         #define I2C_PINSEL_MASK              I2C0_PINSEL_MASK
  80         #define I2C_PCLKSEL                  PCLKSEL0
  81         #define I2C_PCLK_MASK                I2C0_PCLK_MASK
  82         #define I2C_PCLK_DIV8                I2C0_PCLK_DIV8
  83 #else
  84         /* I2C 1 */
  85         #error
  86 #endif
  87
  88 #define GET_STATUS()   ((uint8_t)I2C_STAT)
  89 /*
  90  * Wait that SI bit is set.
  91  *
  92  * Note: this bit is set when the I2C state changes. However, entering
  93  * state F8 does not set SI since there is nothing for an interrupt service
  94  * routine to do in that case.
  95  */
  96 #define WAIT_SI() \
  97         do { \
  98                 ticks_t start = timer_clock(); \
  99                 while( !(I2C_CONSET & BV(I2CON_SI)) ) \
 100                 { \
 101                         if (timer_clock() - start > ms_to_ticks(CONFIG_I2C_START_TIMEOUT)) \
 102                         { \
 103                                 LOG_ERR("Timeout SI assert\n"); \
 104                                 break; \
 105                         } \
 106                 } \
 107         } while (0)
 108
 109 static void i2c_hw_restart(void)
 110 {
 111         // Clear all pending flags.
 112         I2C_CONCLR = BV(I2CON_STAC) | BV(I2CON_SIC) | BV(I2CON_AAC);
 113
 114         // Set start and ack bit.
 115         I2C_CONSET = BV(I2CON_STA);
 116
 117         WAIT_SI();
 118 }
 119
 120
 121 static void i2c_hw_stop(void)
 122 {
 123         /* Set the stop bit */
 124         I2C_CONSET = BV(I2CON_STO);
 125         /* Clear pending flags */
 126         I2C_CONCLR = BV(I2CON_STAC) | BV(I2CON_SIC) | BV(I2CON_AAC);
 127 }
 128
 129 static void i2c_lpc2_put(I2c *i2c, uint8_t data)
 130 {
 131         I2C_DAT = data;
 132
 133 //      kprintf("w %02x\n", data);
 134
 135         I2C_CONCLR = BV(I2CON_SIC);
 136
 137         WAIT_SI();
 138
 139         uint32_t status = GET_STATUS();
 140         //kprintf("w %08lx\n", status);
 141
 142         /* if (status == I2C_STAT_DATA_ACK) */
 143
 144         /* Generate the stop if we finish to send all programmed bytes */
 145         if (i2c->xfer_size == 1)
 146         {
 147                 if (I2C_TEST_STOP(i2c->flags) == I2C_STOP)
 148                         i2c_hw_stop();
 149         }
 150
 151         if (status == I2C_STAT_DATA_NACK)
 152         {
 153                 LOG_ERR("Data NACK\n");
 154                 i2c->errors |= I2C_NO_ACK;
 155                 i2c_hw_stop();
 156         }
 157         else if ((status == I2C_STAT_ERROR) || (status == I2C_STAT_UNKNOW))
 158         {
 159                 LOG_ERR("I2C error.\n");
 160                 i2c->errors |= I2C_ERR;
 161                 i2c_hw_stop();
 162         }
 163 }
 164
 165 static uint8_t i2c_lpc2_get(I2c *i2c)
 166 {
 167         /*
 168          * Set ack bit if we want read more byte, otherwise
 169          * we disable it
 170          */
 171         if (i2c->xfer_size > 1)
 172                 I2C_CONSET = BV(I2CON_AA);
 173         else
 174                 I2C_CONCLR = BV(I2CON_AAC);
 175
 176         I2C_CONCLR = BV(I2CON_SIC);
 177
 178         WAIT_SI();
 179
 180         uint32_t status = GET_STATUS();
 181         uint8_t data = (uint8_t)(I2C_DAT & 0xFF);
 182
 183 //      kprintf("r %02x\n", data);
 184 //      kprintf("r %08lx\n", status);
 185
 186         if (status == I2C_STAT_RDATA_ACK)
 187         {
 188                 return data;
 189         }
 190         else if (status == I2C_STAT_RDATA_NACK)
 191         {
 192                 /*
 193                  * last byte to read generate the stop if
 194                  * required
 195                  */
 196                 if (I2C_TEST_STOP(i2c->flags) == I2C_STOP)
 197                         i2c_hw_stop();
 198
 199                 return data;
 200         }
 201         else if ((status == I2C_STAT_ERROR) || (status == I2C_STAT_UNKNOW))
 202         {
 203                 LOG_ERR("I2C error.\n");
 204                 i2c->errors |= I2C_ERR;
 205                 i2c_hw_stop();
 206         }
 207
 208         return 0xFF;
 209 }
 210
 211 MOD_DEFINE(i2c);
 212
 213 static void i2c_lpc2_start(struct I2c *i2c, uint16_t slave_addr)
 214 {
 215         if (I2C_TEST_START(i2c->flags) == I2C_START_W)
 216         {
 217                 ticks_t start = timer_clock();
 218                 while (true)
 219                 {
 220                         i2c_hw_restart();
 221
 222                         uint8_t status = GET_STATUS();
 223
 224                         /* Start status ok, set addres and the R/W bit */
 225                         if ((status == I2C_STAT_SEND) || (status == I2C_STAT_RESEND))
 226                                 I2C_DAT = slave_addr & ~I2C_READBIT;
 227
 228                         /* Clear the start bit and clear the SI bit */
 229                         I2C_CONCLR = BV(I2CON_SIC) | BV(I2CON_STAC);
 230
 231                         if (status == I2C_STAT_SLAW_ACK)
 232                                 break;
 233                         else if (status == I2C_STAT_ARB_LOST)
 234                         {
 235                                 LOG_ERR("Arbitration lost\n");
 236                                 i2c->errors |= I2C_ARB_LOST;
 237                                 i2c_hw_stop();
 238                                 break;
 239                         }
 240
 241                         if (timer_clock() - start > ms_to_ticks(CONFIG_I2C_START_TIMEOUT))
 242                         {
 243                                 LOG_ERR("Timeout on I2C START\n");
 244                                 i2c->errors |= I2C_NO_ACK;
 245                                 i2c_hw_stop();
 246                                 break;
 247                         }
 248                 }
 249         }
 250         else if (I2C_TEST_START(i2c->flags) == I2C_START_R)
 251         {
 252                 i2c_hw_restart();
 253
 254                 uint8_t status = GET_STATUS();
 255
 256                 /* Start status ok, set addres and the R/W bit */
 257                 if ((status == I2C_STAT_SEND) || (status == I2C_STAT_RESEND))
 258                         I2C_DAT = slave_addr | I2C_READBIT;
 259
 260                 /* Clear the start bit and clear the SI bit */
 261                 I2C_CONCLR = BV(I2CON_SIC) | BV(I2CON_STAC);
 262
 263                 WAIT_SI();
 264
 265                 status = GET_STATUS();
 266 /*
 267                 if (status == I2C_STAT_SLAR_ACK)
 268                         break;
 269 */
 270                 if (status == I2C_STAT_SLAR_NACK)
 271                 {
 272                         LOG_ERR("SLAR NACK:%02x\n", status);
 273                         i2c->errors |= I2C_NO_ACK;
 274                         i2c_hw_stop();
 275                 }
 276                 else if (status == I2C_STAT_ARB_LOST)
 277                 {
 278                         LOG_ERR("Arbitration lost\n");
 279                         i2c->errors |= I2C_ARB_LOST;
 280                         i2c_hw_stop();
 281                 }
 282         }
 283         else
 284         {
 285                 ASSERT(0);
 286         }
 287
 288 }
 289
 290 static const I2cVT i2c_lpc_vt =
 291 {
 292         .start = i2c_lpc2_start,
 293         .get = i2c_lpc2_get,
 294         .put = i2c_lpc2_put,
 295         .send = i2c_swSend,
 296         .recv = i2c_swRecv,
 297 };
 298
 299 struct I2cHardware i2c_lpc2_hw =
 300 {
 301         .dev = 0,
 302 };
 303
 304
 305 /**
 306  * Initialize I2C module.
 307  */
 308 void i2c_hw_init(I2c *i2c, int dev, uint32_t clock)
 309 {
 310         i2c->hw = &i2c_lpc2_hw;
 311         i2c->vt = &i2c_lpc_vt;
 312
 313         /* Enable I2C clock */
 314         PCONP |= BV(I2C_PCONP);
 315
 316         ASSERT(clock <= 400000);
 317
 318         I2C_CONCLR = BV(I2CON_I2ENC) | BV(I2CON_STAC) | BV(I2CON_SIC) | BV(I2CON_AAC);
 319
 320         /*
 321          * Bit Frequency = Fplk / (I2C_I2SCLH + I2C_I2SCLL)
 322          * value of I2SCLH and I2SCLL must be different
 323          */
 324         I2C_PCLKSEL &= ~I2C_PCLK_MASK;
 325         I2C_PCLKSEL |= I2C_PCLK_DIV8;
 326
 327         I2C_SCLH = (((CPU_FREQ / 8) / clock) / 2) + 1;
 328         I2C_SCLL = (((CPU_FREQ / 8) / clock) / 2);
 329
 330         ASSERT(I2C_SCLH > 4 || I2C_SCLL > 4);
 331
 332         /* Assign pins to SCL and SDA (P0_27, P0_28) */
 333         I2C_PINSEL_PORT &= ~I2C_PINSEL_MASK;
 334         I2C_PINSEL_PORT |= I2C_PINSEL;
 335
 336         // Enable I2C
 337         I2C_CONSET = BV(I2CON_I2EN);
 338
 339         MOD_INIT(i2c);
 340 }