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>

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;
 	}
 }