]> git.kernelconcepts.de Git - karo-tx-uboot.git/commitdiff
ARM: I2C: I2C Multi byte address support
authorPatil, Rachna <rachna@ti.com>
Sun, 22 Jan 2012 23:44:12 +0000 (23:44 +0000)
committerHeiko Schocher <hs@denx.de>
Mon, 23 Jan 2012 10:57:31 +0000 (11:57 +0100)
Existing OMAP I2C driver does not support address
length greater than one. Hence this patch is to
add support for 2 byte address read/write.

Signed-off-by: Philip, Avinash <avinashphilip@ti.com>
Signed-off-by: Hebbar, Gururaja <gururaja.hebbar@ti.com>
Signed-off-by: Patil, Rachna <rachna@ti.com>
drivers/i2c/omap24xx_i2c.c
drivers/i2c/omap24xx_i2c.h

index a7ffd95d5d7f4d19d82a5041d88774e66f21ce1a..80932eff8149733c76d276221714a5adfbbc6bab 100644 (file)
 
 DECLARE_GLOBAL_DATA_PTR;
 
-#define I2C_TIMEOUT    1000
+#define I2C_STAT_TIMEO (1 << 31)
+#define I2C_TIMEOUT    10
 
-static void wait_for_bb(void);
-static u16 wait_for_pin(void);
+static u32 wait_for_bb(void);
+static u32 wait_for_status_mask(u16 mask);
 static void flush_fifo(void);
 
 /*
@@ -50,7 +51,6 @@ void i2c_init(int speed, int slaveadd)
        int psc, fsscll, fssclh;
        int hsscll = 0, hssclh = 0;
        u32 scll, sclh;
-       int timeout = I2C_TIMEOUT;
 
        /* Only handle standard, fast and high speeds */
        if ((speed != OMAP_I2C_STANDARD) &&
@@ -112,24 +112,14 @@ void i2c_init(int speed, int slaveadd)
                sclh = (unsigned int)fssclh;
        }
 
+       if (gd->flags & GD_FLG_RELOC)
+               bus_initialized[current_bus] = 1;
+
        if (readw(&i2c_base->con) & I2C_CON_EN) {
                writew(0, &i2c_base->con);
                udelay(50000);
        }
 
-       writew(0x2, &i2c_base->sysc); /* for ES2 after soft reset */
-       udelay(1000);
-
-       writew(I2C_CON_EN, &i2c_base->con);
-       while (!(readw(&i2c_base->syss) & I2C_SYSS_RDONE) && timeout--) {
-               if (timeout <= 0) {
-                       puts("ERROR: Timeout in soft-reset\n");
-                       return;
-               }
-               udelay(1000);
-       }
-
-       writew(0, &i2c_base->con);
        writew(psc, &i2c_base->psc);
        writew(scll, &i2c_base->scll);
        writew(sclh, &i2c_base->sclh);
@@ -145,81 +135,6 @@ void i2c_init(int speed, int slaveadd)
        flush_fifo();
        writew(0xFFFF, &i2c_base->stat);
        writew(0, &i2c_base->cnt);
-
-       if (gd->flags & GD_FLG_RELOC)
-               bus_initialized[current_bus] = 1;
-}
-
-static int i2c_read_byte(u8 devaddr, u8 regoffset, u8 *value)
-{
-       int i2c_error = 0;
-       u16 status;
-
-       /* wait until bus not busy */
-       wait_for_bb();
-
-       /* one byte only */
-       writew(1, &i2c_base->cnt);
-       /* set slave address */
-       writew(devaddr, &i2c_base->sa);
-       /* no stop bit needed here */
-       writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_STT |
-             I2C_CON_TRX, &i2c_base->con);
-
-       /* send register offset */
-       while (1) {
-               status = wait_for_pin();
-               if (status == 0 || status & I2C_STAT_NACK) {
-                       i2c_error = 1;
-                       goto read_exit;
-               }
-               if (status & I2C_STAT_XRDY) {
-                       /* Important: have to use byte access */
-                       writeb(regoffset, &i2c_base->data);
-                       writew(I2C_STAT_XRDY, &i2c_base->stat);
-               }
-               if (status & I2C_STAT_ARDY) {
-                       writew(I2C_STAT_ARDY, &i2c_base->stat);
-                       break;
-               }
-       }
-
-       /* set slave address */
-       writew(devaddr, &i2c_base->sa);
-       /* read one byte from slave */
-       writew(1, &i2c_base->cnt);
-       /* need stop bit here */
-       writew(I2C_CON_EN | I2C_CON_MST |
-               I2C_CON_STT | I2C_CON_STP,
-               &i2c_base->con);
-
-       /* receive data */
-       while (1) {
-               status = wait_for_pin();
-               if (status == 0 || status & I2C_STAT_NACK) {
-                       i2c_error = 1;
-                       goto read_exit;
-               }
-               if (status & I2C_STAT_RRDY) {
-#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX) || \
-       defined(CONFIG_OMAP44XX)
-                       *value = readb(&i2c_base->data);
-#else
-                       *value = readw(&i2c_base->data);
-#endif
-                       writew(I2C_STAT_RRDY, &i2c_base->stat);
-               }
-               if (status & I2C_STAT_ARDY) {
-                       writew(I2C_STAT_ARDY, &i2c_base->stat);
-                       break;
-               }
-       }
-
-read_exit:
-       flush_fifo();
-       writew(0xFFFF, &i2c_base->stat);
-       writew(0, &i2c_base->cnt);
-       return i2c_error;
 }
 
 static void flush_fifo(void)
@@ -246,32 +161,42 @@ static void flush_fifo(void)
 
 int i2c_probe(uchar chip)
 {
-       u16 status;
+       u32 status;
        int res = 1; /* default = fail */
 
        if (chip == readw(&i2c_base->oa))
                return res;
 
        /* wait until bus not busy */
-       wait_for_bb();
+       status = wait_for_bb();
+       /* exit on BUS busy */
+       if (status & I2C_STAT_TIMEO)
+               return res;
 
        /* try to write one byte */
        writew(1, &i2c_base->cnt);
        /* set slave address */
        writew(chip, &i2c_base->sa);
        /* stop bit needed here */
-       writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_TRX |
-              I2C_CON_STP, &i2c_base->con);
-
-       status = wait_for_pin();
-
-       /* check for ACK (!NAK) */
-       if (!(status & I2C_STAT_NACK))
-               res = 0;
-
-       /* abort transfer (force idle state) */
-       writew(0, &i2c_base->con);
-
+       writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_STT
+                       | I2C_CON_STP, &i2c_base->con);
+       /* enough delay for the NACK bit set */
+       udelay(9000);
+
+       if (!(readw(&i2c_base->stat) & I2C_STAT_NACK)) {
+               res = 0;      /* success case */
+               flush_fifo();
+               writew(0xFFFF, &i2c_base->stat);
+       } else {
+               /* failure, clear sources*/
+               writew(0xFFFF, &i2c_base->stat);
+               /* finish up xfer */
+               writew(readw(&i2c_base->con) | I2C_CON_STP, &i2c_base->con);
+               status = wait_for_bb();
+               /* exit on BUS busy */
+               if (status & I2C_STAT_TIMEO)
+                       return res;
+       }
        flush_fifo();
        /* don't allow any more data in... we don't want it. */
        writew(0, &i2c_base->cnt);
@@ -281,111 +206,309 @@ int i2c_probe(uchar chip)
 
 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
 {
-       int i;
+       int i2c_error = 0, i;
+       u32 status;
+
+       if ((alen > 2) || (alen < 0))
+               return 1;
 
-       if (alen > 1) {
-               printf("I2C read: addr len %d not supported\n", alen);
+       if (alen < 2) {
+               if (addr + len > 256)
+                       return 1;
+       } else if (addr + len > 0xFFFF) {
                return 1;
        }
 
-       if (addr + len > 256) {
-               puts("I2C read: address out of range\n");
+       /* wait until bus not busy */
+       status = wait_for_bb();
+
+       /* exit on BUS busy */
+       if (status & I2C_STAT_TIMEO)
                return 1;
+
+       writew((alen & 0xFF), &i2c_base->cnt);
+       /* set slave address */
+       writew(chip, &i2c_base->sa);
+       /* Clear the Tx & Rx FIFOs */
+       writew((readw(&i2c_base->buf) | I2C_RXFIFO_CLEAR |
+               I2C_TXFIFO_CLEAR), &i2c_base->buf);
+       /* no stop bit needed here */
+       writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_TRX |
+               I2C_CON_STT, &i2c_base->con);
+
+       /* wait for Transmit ready condition */
+       status = wait_for_status_mask(I2C_STAT_XRDY | I2C_STAT_NACK);
+
+       if (status & (I2C_STAT_NACK | I2C_STAT_TIMEO))
+               i2c_error = 1;
+
+       if (!i2c_error) {
+               if (status & I2C_STAT_XRDY) {
+                       switch (alen) {
+                       case 2:
+                               /* Send address MSByte */
+#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX)
+                               writew(((addr >> 8) & 0xFF), &i2c_base->data);
+
+                               /* Clearing XRDY event */
+                               writew((status & I2C_STAT_XRDY),
+                                               &i2c_base->stat);
+                               /* wait for Transmit ready condition */
+                               status = wait_for_status_mask(I2C_STAT_XRDY |
+                                               I2C_STAT_NACK);
+
+                               if (status & (I2C_STAT_NACK |
+                                               I2C_STAT_TIMEO)) {
+                                       i2c_error = 1;
+                                       break;
+                               }
+#endif
+                       case 1:
+#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX)
+                               /* Send address LSByte */
+                               writew((addr & 0xFF), &i2c_base->data);
+#else
+                               /* Send address Short word */
+                               writew((addr & 0xFFFF), &i2c_base->data);
+#endif
+                               /* Clearing XRDY event */
+                               writew((status & I2C_STAT_XRDY),
+                                       &i2c_base->stat);
+                               /*wait for Transmit ready condition */
+                               status = wait_for_status_mask(I2C_STAT_ARDY |
+                                               I2C_STAT_NACK);
+
+                               if (status & (I2C_STAT_NACK |
+                                       I2C_STAT_TIMEO)) {
+                                       i2c_error = 1;
+                                       break;
+                               }
+                       }
+               } else
+                       i2c_error = 1;
        }
 
-       for (i = 0; i < len; i++) {
-               if (i2c_read_byte(chip, addr + i, &buffer[i])) {
-                       puts("I2C read: I/O error\n");
-                       i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
-                       return 1;
+       /* Wait for ARDY to set */
+       status = wait_for_status_mask(I2C_STAT_ARDY | I2C_STAT_NACK
+                       | I2C_STAT_AL);
+
+       if (!i2c_error) {
+               /* set slave address */
+               writew(chip, &i2c_base->sa);
+               writew((len & 0xFF), &i2c_base->cnt);
+               /* Clear the Tx & Rx FIFOs */
+               writew((readw(&i2c_base->buf) | I2C_RXFIFO_CLEAR |
+                       I2C_TXFIFO_CLEAR), &i2c_base->buf);
+               /* need stop bit here */
+               writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_STP,
+                       &i2c_base->con);
+
+               for (i = 0; i < len; i++) {
+                       /* wait for Receive condition */
+                       status = wait_for_status_mask(I2C_STAT_RRDY |
+                               I2C_STAT_NACK);
+                       if (status & (I2C_STAT_NACK | I2C_STAT_TIMEO)) {
+                               i2c_error = 1;
+                               break;
+                       }
+
+                       if (status & I2C_STAT_RRDY) {
+#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX)
+                               buffer[i] = readb(&i2c_base->data);
+#else
+                               *((u16 *)&buffer[i]) =
+                                       readw(&i2c_base->data) & 0xFFFF;
+                               i++;
+#endif
+                               writew((status & I2C_STAT_RRDY),
+                                       &i2c_base->stat);
+                               udelay(1000);
+                       } else {
+                               i2c_error = 1;
+                       }
                }
        }
 
+       /* Wait for ARDY to set */
+       status = wait_for_status_mask(I2C_STAT_ARDY | I2C_STAT_NACK
+                       | I2C_STAT_AL);
+
+       if (i2c_error) {
+               writew(0, &i2c_base->con);
+               return 1;
+       }
+
+       writew(I2C_CON_EN, &i2c_base->con);
+
+       while (readw(&i2c_base->stat)
+               || (readw(&i2c_base->con) & I2C_CON_MST)) {
+               udelay(10000);
+               writew(0xFFFF, &i2c_base->stat);
+       }
+
+       writew(I2C_CON_EN, &i2c_base->con);
+       flush_fifo();
+       writew(0xFFFF, &i2c_base->stat);
+       writew(0, &i2c_base->cnt);
+
        return 0;
 }
 
 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
 {
-       int i;
-       u16 status;
-       int i2c_error = 0;
 
-       if (alen > 1) {
-               printf("I2C write: addr len %d not supported\n", alen);
+       int i, i2c_error = 0;
+       u32 status;
+       u16 writelen;
+
+       if (alen > 2)
                return 1;
-       }
 
-       if (addr + len > 256) {
-               printf("I2C write: address 0x%x + 0x%x out of range\n",
-                               addr, len);
+       if (alen < 2) {
+               if (addr + len > 256)
+                       return 1;
+       } else if (addr + len > 0xFFFF) {
                return 1;
        }
 
        /* wait until bus not busy */
-       wait_for_bb();
+       status = wait_for_bb();
+
+       /* exiting on BUS busy */
+       if (status & I2C_STAT_TIMEO)
+               return 1;
 
-       /* start address phase - will write regoffset + len bytes data */
-       /* TODO consider case when !CONFIG_OMAP243X/34XX/44XX */
-       writew(alen + len, &i2c_base->cnt);
+       writelen = (len & 0xFFFF) + alen;
+
+       /* two bytes */
+       writew((writelen & 0xFFFF), &i2c_base->cnt);
+       /* Clear the Tx & Rx FIFOs */
+       writew((readw(&i2c_base->buf) | I2C_RXFIFO_CLEAR |
+                       I2C_TXFIFO_CLEAR), &i2c_base->buf);
        /* set slave address */
        writew(chip, &i2c_base->sa);
        /* stop bit needed here */
        writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_TRX |
                I2C_CON_STP, &i2c_base->con);
 
-       /* Send address byte */
-       status = wait_for_pin();
+       /* wait for Transmit ready condition */
+       status = wait_for_status_mask(I2C_STAT_XRDY | I2C_STAT_NACK);
 
-       if (status == 0 || status & I2C_STAT_NACK) {
+       if (status & (I2C_STAT_NACK | I2C_STAT_TIMEO))
                i2c_error = 1;
-               printf("error waiting for i2c address ACK (status=0x%x)\n",
-                     status);
-               goto write_exit;
-       }
 
-       if (status & I2C_STAT_XRDY) {
-               writeb(addr & 0xFF, &i2c_base->data);
-               writew(I2C_STAT_XRDY, &i2c_base->stat);
-       } else {
-               i2c_error = 1;
-               printf("i2c bus not ready for transmit (status=0x%x)\n",
-                     status);
-               goto write_exit;
-       }
+       if (!i2c_error) {
+               if (status & I2C_STAT_XRDY) {
+                       switch (alen) {
+#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX)
+                       case 2:
+                               /* send out MSB byte */
+                               writeb(((addr >> 8) & 0xFF), &i2c_base->data);
+#else
+                               writeb((addr  & 0xFFFF), &i2c_base->data);
+                               break;
+#endif
+                               /* Clearing XRDY event */
+                               writew((status & I2C_STAT_XRDY),
+                                       &i2c_base->stat);
+                               /*waiting for Transmit ready * condition */
+                               status = wait_for_status_mask(I2C_STAT_XRDY |
+                                               I2C_STAT_NACK);
+
+                               if (status & (I2C_STAT_NACK | I2C_STAT_TIMEO)) {
+                                       i2c_error = 1;
+                                       break;
+                               }
+                       case 1:
+#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX)
+                               /* send out MSB byte */
+                               writeb((addr  & 0xFF), &i2c_base->data);
+#else
+                               writew(((buffer[0] << 8) | (addr & 0xFF)),
+                                       &i2c_base->data);
+#endif
+                       }
 
-       /* address phase is over, now write data */
-       for (i = 0; i < len; i++) {
-               status = wait_for_pin();
+                       /* Clearing XRDY event */
+                       writew((status & I2C_STAT_XRDY), &i2c_base->stat);
+               }
+
+               /* waiting for Transmit ready condition */
+               status = wait_for_status_mask(I2C_STAT_XRDY | I2C_STAT_NACK);
 
-               if (status == 0 || status & I2C_STAT_NACK) {
+               if (status & (I2C_STAT_NACK | I2C_STAT_TIMEO))
                        i2c_error = 1;
-                       printf("i2c error waiting for data ACK (status=0x%x)\n",
-                                       status);
-                       goto write_exit;
+
+               if (!i2c_error) {
+                       for (i = ((alen > 1) ? 0 : 1); i < len; i++) {
+                               if (status & I2C_STAT_XRDY) {
+#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX)
+                                       writeb((buffer[i] & 0xFF),
+                                               &i2c_base->data);
+#else
+                                       writew((((buffer[i] << 8) |
+                                       buffer[i + 1]) & 0xFFFF),
+                                               &i2c_base->data);
+                                       i++;
+#endif
+                               } else
+                                       i2c_error = 1;
+                                       /* Clearing XRDY event */
+                                       writew((status & I2C_STAT_XRDY),
+                                               &i2c_base->stat);
+                                       /* waiting for XRDY condition */
+                                       status = wait_for_status_mask(
+                                               I2C_STAT_XRDY |
+                                               I2C_STAT_ARDY |
+                                               I2C_STAT_NACK);
+                                       if (status & (I2C_STAT_NACK |
+                                               I2C_STAT_TIMEO)) {
+                                               i2c_error = 1;
+                                               break;
+                                       }
+                                       if (status & I2C_STAT_ARDY)
+                                               break;
+                       }
                }
+       }
 
-               if (status & I2C_STAT_XRDY) {
-                       writeb(buffer[i], &i2c_base->data);
-                       writew(I2C_STAT_XRDY, &i2c_base->stat);
-               } else {
-                       i2c_error = 1;
-                       printf("i2c bus not ready for Tx (i=%d)\n", i);
-                       goto write_exit;
+       status = wait_for_status_mask(I2C_STAT_ARDY | I2C_STAT_NACK |
+                               I2C_STAT_AL);
+
+       if (status & (I2C_STAT_NACK | I2C_STAT_TIMEO))
+               i2c_error = 1;
+
+       if (i2c_error) {
+               writew(0, &i2c_base->con);
+               return 1;
+       }
+
+       if (!i2c_error) {
+               int eout = 200;
+
+               writew(I2C_CON_EN, &i2c_base->con);
+               while ((status = readw(&i2c_base->stat)) ||
+                               (readw(&i2c_base->con) & I2C_CON_MST)) {
+                       udelay(1000);
+                       /* have to read to clear intrrupt */
+                       writew(0xFFFF, &i2c_base->stat);
+                       if (--eout == 0)
+                               /* better leave with error than hang */
+                               break;
                }
        }
 
-write_exit:
        flush_fifo();
        writew(0xFFFF, &i2c_base->stat);
-       return i2c_error;
+       writew(0, &i2c_base->cnt);
+       return 0;
 }
 
-static void wait_for_bb(void)
+static u32 wait_for_bb(void)
 {
        int timeout = I2C_TIMEOUT;
-       u16 stat;
+       u32 stat;
 
-       writew(0xFFFF, &i2c_base->stat);        /* clear current interrupts...*/
        while ((stat = readw(&i2c_base->stat) & I2C_STAT_BB) && timeout--) {
                writew(stat, &i2c_base->stat);
                udelay(1000);
@@ -394,30 +517,28 @@ static void wait_for_bb(void)
        if (timeout <= 0) {
                printf("timed out in wait_for_bb: I2C_STAT=%x\n",
                        readw(&i2c_base->stat));
+               stat |= I2C_STAT_TIMEO;
        }
        writew(0xFFFF, &i2c_base->stat);         /* clear delayed stuff*/
+       return stat;
 }
 
-static u16 wait_for_pin(void)
+static u32 wait_for_status_mask(u16 mask)
 {
-       u16 status;
+       u32 status;
        int timeout = I2C_TIMEOUT;
 
        do {
                udelay(1000);
                status = readw(&i2c_base->stat);
-       } while (!(status &
-                  (I2C_STAT_ROVR | I2C_STAT_XUDF | I2C_STAT_XRDY |
-                   I2C_STAT_RRDY | I2C_STAT_ARDY | I2C_STAT_NACK |
-                   I2C_STAT_AL)) && timeout--);
+       } while (!(status & mask) && timeout--);
 
        if (timeout <= 0) {
-               printf("timed out in wait_for_pin: I2C_STAT=%x\n",
+               printf("timed out in wait_for_status_mask: I2C_STAT=%x\n",
                        readw(&i2c_base->stat));
                writew(0xFFFF, &i2c_base->stat);
-               status = 0;
+               status |= I2C_STAT_TIMEO;
        }
-
        return status;
 }
 
index 1f38c232d16461c8f077c40573f637a8957ab2b3..9a0b126b387825c9f7d8d20f2dcacc79a07ab0b9 100644 (file)
@@ -60,7 +60,9 @@
 /* I2C Buffer Configuration Register (I2C_BUF): */
 
 #define I2C_BUF_RDMA_EN                (1 << 15) /* Receive DMA channel enable */
+#define I2C_RXFIFO_CLEAR       (1 << 14) /* RX FIFO Clear */
 #define I2C_BUF_XDMA_EN                (1 << 7)  /* Transmit DMA channel enable */
+#define I2C_TXFIFO_CLEAR       (1 << 6)  /* TX FIFO clear */
 
 /* I2C Configuration Register (I2C_CON): */