blackfin: make i2c driver blackfin independant

The ADI twi peripheral is not binding to Blackfin processor only.
Access i2c registers by standard io functions.
Fix coding style.

Signed-off-by: Scott Jiang <scott.jiang.linux@gmail.com>
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>

diff --git a/drivers/i2c/adi_i2c.c b/drivers/i2c/adi_i2c.c
index 743aa25..675f417 100644 (file)
--- a/drivers/i2c/adi_i2c.c
+++ b/drivers/i2c/adi_i2c.c
@@ -1,7 +1,7 @@
 /*
- * i2c.c - driver for Blackfin on-chip TWI/I2C
+ * i2c.c - driver for ADI TWI/I2C
  *
- * Copyright (c) 2006-2010 Analog Devices Inc.
+ * Copyright (c) 2006-2013 Analog Devices Inc.
  *
  * Licensed under the GPL-2 or later.
  */
@@ -11,6 +11,7 @@
 
 #include <asm/clock.h>
 #include <asm/twi.h>
+#include <asm/io.h>
 
 /* Every register is 32bit aligned, but only 16bits in size */
 #define ureg(name) u16 name; u16 __pad_##name;
@@ -39,7 +40,7 @@ struct twi_regs {
 #ifdef TWI_CLKDIV
 #define TWI0_CLKDIV TWI_CLKDIV
 #endif
-static volatile struct twi_regs *twi = (void *)TWI0_CLKDIV;
+static struct twi_regs *twi = (void *)TWI0_CLKDIV;
 
 #ifdef DEBUG
 # define dmemset(s, c, n) memset(s, c, n)
@@ -93,53 +94,54 @@ struct i2c_msg {
  */
 static int wait_for_completion(struct i2c_msg *msg)
 {
-       uint16_t int_stat;
+       u16 int_stat, ctl;
        ulong timebase = get_timer(0);
 
        do {
-               int_stat = twi->int_stat;
+               int_stat = readw(&twi->int_stat);
 
                if (int_stat & XMTSERV) {
                        debugi("processing XMTSERV");
-                       twi->int_stat = XMTSERV;
-                       SSYNC();
+                       writew(XMTSERV, &twi->int_stat);
                        if (msg->alen) {
-                               twi->xmt_data8 = *(msg->abuf++);
+                               writew(*(msg->abuf++), &twi->xmt_data8);
                                --msg->alen;
                        } else if (!(msg->flags & I2C_M_COMBO) && msg->len) {
-                               twi->xmt_data8 = *(msg->buf++);
+                               writew(*(msg->buf++), &twi->xmt_data8);
                                --msg->len;
                        } else {
-                               twi->master_ctl |= (msg->flags & I2C_M_COMBO) ? RSTART | MDIR : STOP;
-                               SSYNC();
+                               ctl = readw(&twi->master_ctl);
+                               if (msg->flags & I2C_M_COMBO)
+                                       writew(ctl | RSTART | MDIR,
+                                                       &twi->master_ctl);
+                               else
+                                       writew(ctl | STOP, &twi->master_ctl);
                        }
                }
                if (int_stat & RCVSERV) {
                        debugi("processing RCVSERV");
-                       twi->int_stat = RCVSERV;
-                       SSYNC();
+                       writew(RCVSERV, &twi->int_stat);
                        if (msg->len) {
-                               *(msg->buf++) = twi->rcv_data8;
+                               *(msg->buf++) = readw(&twi->rcv_data8);
                                --msg->len;
                        } else if (msg->flags & I2C_M_STOP) {
-                               twi->master_ctl |= STOP;
-                               SSYNC();
+                               ctl = readw(&twi->master_ctl);
+                               writew(ctl | STOP, &twi->master_ctl);
                        }
                }
                if (int_stat & MERR) {
                        debugi("processing MERR");
-                       twi->int_stat = MERR;
-                       SSYNC();
+                       writew(MERR, &twi->int_stat);
                        return msg->len;
                }
                if (int_stat & MCOMP) {
                        debugi("processing MCOMP");
-                       twi->int_stat = MCOMP;
-                       SSYNC();
+                       writew(MCOMP, &twi->int_stat);
                        if (msg->flags & I2C_M_COMBO && msg->len) {
-                               twi->master_ctl = (twi->master_ctl & ~RSTART) |
+                               ctl = readw(&twi->master_ctl);
+                               ctl = (ctl & ~RSTART) |
                                        (min(msg->len, 0xff) << 6) | MEN | MDIR;
-                               SSYNC();
+                               writew(ctl, &twi->master_ctl);
                        } else
                                break;
                }
@@ -160,8 +162,11 @@ static int wait_for_completion(struct i2c_msg *msg)
  *     Here we just get the i2c stuff all prepped and ready, and then tail off
  *     into wait_for_completion() for all the bits to go.
  */
-static int i2c_transfer(uchar chip, uint addr, int alen, uchar *buffer, int len, u8 flags)
+static int i2c_transfer(uchar chip, uint addr, int alen, uchar *buffer,
+                       int len, u8 flags)
 {
+       int ret;
+       u16 ctl;
        uchar addr_buffer[] = {
                (addr >>  0),
                (addr >>  8),
@@ -174,62 +179,59 @@ static int i2c_transfer(uchar chip, uint addr, int alen, uchar *buffer, int len,
                .abuf  = addr_buffer,
                .alen  = alen,
        };
-       int ret;
 
        dmemset(buffer, 0xff, len);
-       debugi("chip=0x%x addr=0x%02x alen=%i buf[0]=0x%02x len=%i flags=0x%02x[%s] ",
-               chip, addr, alen, buffer[0], len, flags, (flags & I2C_M_READ ? "rd" : "wr"));
+       debugi("chip=0x%x addr=0x%02x alen=%i buf[0]=0x%02x len=%i ",
+               chip, addr, alen, buffer[0], len);
+       debugi("flags=0x%02x[%s] ", flags,
+               (flags & I2C_M_READ ? "rd" : "wr"));
 
        /* wait for things to settle */
-       while (twi->master_stat & BUSBUSY)
+       while (readw(&twi->master_stat) & BUSBUSY)
                if (ctrlc())
                        return 1;
 
        /* Set Transmit device address */
-       twi->master_addr = chip;
+       writew(chip, &twi->master_addr);
 
        /* Clear the FIFO before starting things */
-       twi->fifo_ctl = XMTFLUSH | RCVFLUSH;
-       SSYNC();
-       twi->fifo_ctl = 0;
-       SSYNC();
+       writew(XMTFLUSH | RCVFLUSH, &twi->fifo_ctl);
+       writew(0, &twi->fifo_ctl);
 
        /* prime the pump */
        if (msg.alen) {
                len = (msg.flags & I2C_M_COMBO) ? msg.alen : msg.alen + len;
                debugi("first byte=0x%02x", *msg.abuf);
-               twi->xmt_data8 = *(msg.abuf++);
+               writew(*(msg.abuf++), &twi->xmt_data8);
                --msg.alen;
        } else if (!(msg.flags & I2C_M_READ) && msg.len) {
                debugi("first byte=0x%02x", *msg.buf);
-               twi->xmt_data8 = *(msg.buf++);
+               writew(*(msg.buf++), &twi->xmt_data8);
                --msg.len;
        }
 
        /* clear int stat */
-       twi->master_stat = -1;
-       twi->int_stat = -1;
-       twi->int_mask = 0;
-       SSYNC();
+       writew(-1, &twi->master_stat);
+       writew(-1, &twi->int_stat);
+       writew(0, &twi->int_mask);
 
        /* Master enable */
-       twi->master_ctl =
-                       (twi->master_ctl & FAST) |
-                       (min(len, 0xff) << 6) | MEN |
-                       ((msg.flags & I2C_M_READ) ? MDIR : 0);
-       SSYNC();
-       debugi("CTL=0x%04x", twi->master_ctl);
+       ctl = readw(&twi->master_ctl);
+       ctl = (ctl & FAST) | (min(len, 0xff) << 6) | MEN |
+               ((msg.flags & I2C_M_READ) ? MDIR : 0);
+       writew(ctl, &twi->master_ctl);
 
        /* process the rest */
        ret = wait_for_completion(&msg);
        debugi("ret=%d", ret);
 
        if (ret) {
-               twi->master_ctl &= ~MEN;
-               twi->control &= ~TWI_ENA;
-               SSYNC();
-               twi->control |= TWI_ENA;
-               SSYNC();
+               ctl = readw(&twi->master_ctl) & ~MEN;
+               writew(ctl, &twi->master_ctl);
+               ctl = readw(&twi->control) & ~TWI_ENA;
+               writew(ctl, &twi->control);
+               ctl = readw(&twi->control) | TWI_ENA;
+               writew(ctl, &twi->control);
        }
 
        return ret;
@@ -246,10 +248,11 @@ int i2c_set_bus_speed(unsigned int speed)
        /* Set TWI interface clock */
        if (clkdiv < I2C_DUTY_MAX || clkdiv > I2C_DUTY_MIN)
                return -1;
-       twi->clkdiv = (clkdiv << 8) | (clkdiv & 0xff);
+       clkdiv = (clkdiv << 8) | (clkdiv & 0xff);
+       writew(clkdiv, &twi->clkdiv);
 
        /* Don't turn it on */
-       twi->master_ctl = (speed > 100000 ? FAST : 0);
+       writew(speed > 100000 ? FAST : 0, &twi->master_ctl);
 
        return 0;
 }
@@ -260,8 +263,9 @@ int i2c_set_bus_speed(unsigned int speed)
  */
 unsigned int i2c_get_bus_speed(void)
 {
+       u16 clkdiv = readw(&twi->clkdiv) & 0xff;
        /* 10 MHz / (2 * CLKDIV) -> 5 MHz / CLKDIV */
-       return 5000000 / (twi->clkdiv & 0xff);
+       return 5000000 / clkdiv;
 }
 
 /**
@@ -274,27 +278,22 @@ unsigned int i2c_get_bus_speed(void)
  */
 void i2c_init(int speed, int slaveaddr)
 {
-       uint8_t prescale = ((get_i2c_clk() / 1000 / 1000 + 5) / 10) & 0x7F;
+       u16 prescale = ((get_i2c_clk() / 1000 / 1000 + 5) / 10) & 0x7F;
 
        /* Set TWI internal clock as 10MHz */
-       twi->control = prescale;
+       writew(prescale, &twi->control);
 
        /* Set TWI interface clock as specified */
        i2c_set_bus_speed(speed);
 
        /* Enable it */
-       twi->control = TWI_ENA | prescale;
-       SSYNC();
+       writew(TWI_ENA | prescale, &twi->control);
 
-       debugi("CONTROL:0x%04x CLKDIV:0x%04x", twi->control, twi->clkdiv);
+       debugi("CONTROL:0x%04x CLKDIV:0x%04x", readw(&twi->control),
+               readw(&twi->clkdiv));
 
 #if CONFIG_SYS_I2C_SLAVE
 # error I2C slave support not tested/supported
-       /* If they want us as a slave, do it */
-       if (slaveaddr) {
-               twi->slave_addr = slaveaddr;
-               twi->slave_ctl = SEN;
-       }
 #endif
 }
 
@@ -320,7 +319,8 @@ int i2c_probe(uchar chip)
  */
 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
 {
-       return i2c_transfer(chip, addr, alen, buffer, len, (alen ? I2C_M_COMBO : I2C_M_READ));
+       return i2c_transfer(chip, addr, alen, buffer,
+                       len, (alen ? I2C_M_COMBO : I2C_M_READ));
 }
 
 /**
@@ -346,15 +346,21 @@ int i2c_set_bus_num(unsigned int bus)
 {
        switch (bus) {
 #if CONFIG_SYS_MAX_I2C_BUS > 0
-               case 0: twi = (void *)TWI0_CLKDIV; return 0;
+       case 0:
+               twi = (void *)TWI0_CLKDIV;
+               return 0;
 #endif
 #if CONFIG_SYS_MAX_I2C_BUS > 1
-               case 1: twi = (void *)TWI1_CLKDIV; return 0;
+       case 1:
+               twi = (void *)TWI1_CLKDIV;
+               return 0;
 #endif
 #if CONFIG_SYS_MAX_I2C_BUS > 2
-               case 2: twi = (void *)TWI2_CLKDIV; return 0;
+       case 2:
+               twi = (void *)TWI2_CLKDIV;
+               return 0;
 #endif
-               default: return -1;
+       default: return -1;
        }
 }
 
@@ -365,14 +371,17 @@ unsigned int i2c_get_bus_num(void)
 {
        switch ((unsigned long)twi) {
 #if CONFIG_SYS_MAX_I2C_BUS > 0
-               case TWI0_CLKDIV: return 0;
+       case TWI0_CLKDIV:
+               return 0;
 #endif
 #if CONFIG_SYS_MAX_I2C_BUS > 1
-               case TWI1_CLKDIV: return 1;
+       case TWI1_CLKDIV:
+               return 1;
 #endif
 #if CONFIG_SYS_MAX_I2C_BUS > 2
-               case TWI2_CLKDIV: return 2;
+       case TWI2_CLKDIV:
+               return 2;
 #endif
-               default: return -1;
+       default: return -1;
        }
 }