[U-Boot] [PATCH 1/8] i2c: davinci: Split functions into two parts for future DM support

11 Apr 2017

The i2c driver will be converted to support device model. In preparation
for that change split the various functions into two parts. This will
allow device model specific driver to reuse the majority of the code from
the non device model implementation.
Also rename the probe function to probe_chip to better reflect its
purpose.
Signed-off-by: Franklin S Cooper Jr fcooper@ti.com
---
 drivers/i2c/davinci_i2c.c | 185 +++++++++++++++++++++++++++-------------------
 1 file changed, 110 insertions(+), 75 deletions(-)

diff --git a/drivers/i2c/davinci_i2c.c b/drivers/i2c/davinci_i2c.c
index c5bd38c..a6bce26 100644
--- a/drivers/i2c/davinci_i2c.c
+++ b/drivers/i2c/davinci_i2c.c
@@ -29,9 +29,8 @@
static struct i2c_regs *davinci_get_base(struct i2c_adapter *adap);
-static int wait_for_bus(struct i2c_adapter *adap)
+static int _wait_for_bus(struct i2c_regs *i2c_base)
 {
-	struct i2c_regs *i2c_base = davinci_get_base(adap);
    int	stat, timeout;
REG(&(i2c_base->i2c_stat)) = 0xffff;
@@ -51,10 +50,8 @@ static int wait_for_bus(struct i2c_adapter *adap)
    return 1;
 }
-
-static int poll_i2c_irq(struct i2c_adapter *adap, int mask)
+static int _poll_i2c_irq(struct i2c_regs *i2c_base, int mask)
 {
-	struct i2c_regs *i2c_base = davinci_get_base(adap);
    int	stat, timeout;
for (timeout = 0; timeout < 10; timeout++) {
@@ -68,10 +65,8 @@ static int poll_i2c_irq(struct i2c_adapter *adap, int mask)
    return stat | I2C_TIMEOUT;
 }
-static void flush_rx(struct i2c_adapter *adap)
+static void _flush_rx(struct i2c_regs *i2c_base)
 {
-	struct i2c_regs *i2c_base = davinci_get_base(adap);
-
    while (1) {
    	if (!(REG(&(i2c_base->i2c_stat)) & I2C_STAT_RRDY))
    		break;
@@ -82,9 +77,9 @@ static void flush_rx(struct i2c_adapter *adap)
    }
 }
-static uint davinci_i2c_setspeed(struct i2c_adapter *adap, uint speed)
+static uint _davinci_i2c_setspeed(struct i2c_regs *i2c_base,
+				  uint speed)
 {
-	struct i2c_regs *i2c_base = davinci_get_base(adap);
    uint32_t	div, psc;
psc = 2;
@@ -94,20 +89,18 @@ static uint davinci_i2c_setspeed(struct i2c_adapter *adap, uint speed)
    REG(&(i2c_base->i2c_scll)) = (div * 50) / 100; /* 50% Duty */
    REG(&(i2c_base->i2c_sclh)) = div - REG(&(i2c_base->i2c_scll));
-	adap->speed	= speed;
    return 0;
 }
-static void davinci_i2c_init(struct i2c_adapter *adap, int speed, int slaveadd)
+static void _davinci_i2c_init(struct i2c_regs *i2c_base,
+			      uint speed, int slaveadd)
 {
-	struct i2c_regs *i2c_base = davinci_get_base(adap);
-
    if (REG(&(i2c_base->i2c_con)) & I2C_CON_EN) {
    	REG(&(i2c_base->i2c_con)) = 0;
    	udelay(50000);
    }
-	davinci_i2c_setspeed(adap, speed);
+	_davinci_i2c_setspeed(i2c_base, speed);
REG(&(i2c_base->i2c_oa)) = slaveadd;
    REG(&(i2c_base->i2c_cnt)) = 0;
@@ -122,47 +115,9 @@ static void davinci_i2c_init(struct i2c_adapter *adap, int speed, int slaveadd)
    udelay(1000);
 }
-static int davinci_i2c_probe(struct i2c_adapter *adap, uint8_t chip)
+static int _davinci_i2c_read(struct i2c_regs *i2c_base, uint8_t chip,
+			     uint32_t addr, int alen, uint8_t *buf, int len)
 {
-	struct i2c_regs *i2c_base = davinci_get_base(adap);
-	int	rc = 1;
-
-	if (chip == REG(&(i2c_base->i2c_oa)))
-		return rc;
-
-	REG(&(i2c_base->i2c_con)) = 0;
-	if (wait_for_bus(adap))
-		return 1;
-
-	/* try to read one byte from current (or only) address */
-	REG(&(i2c_base->i2c_cnt)) = 1;
-	REG(&(i2c_base->i2c_sa))  = chip;
-	REG(&(i2c_base->i2c_con)) = (I2C_CON_EN | I2C_CON_MST | I2C_CON_STT |
-				     I2C_CON_STP);
-	udelay(50000);
-
-	if (!(REG(&(i2c_base->i2c_stat)) & I2C_STAT_NACK)) {
-		rc = 0;
-		flush_rx(adap);
-		REG(&(i2c_base->i2c_stat)) = 0xffff;
-	} else {
-		REG(&(i2c_base->i2c_stat)) = 0xffff;
-		REG(&(i2c_base->i2c_con)) |= I2C_CON_STP;
-		udelay(20000);
-		if (wait_for_bus(adap))
-			return 1;
-	}
-
-	flush_rx(adap);
-	REG(&(i2c_base->i2c_stat)) = 0xffff;
-	REG(&(i2c_base->i2c_cnt)) = 0;
-	return rc;
-}
-
-static int davinci_i2c_read(struct i2c_adapter *adap, uint8_t chip,
-				uint32_t addr, int alen, uint8_t *buf, int len)
-{
-	struct i2c_regs *i2c_base = davinci_get_base(adap);
    uint32_t	tmp;
    int		i;
@@ -171,7 +126,7 @@ static int davinci_i2c_read(struct i2c_adapter *adap, uint8_t chip,
    	return 1;
    }
-	if (wait_for_bus(adap))
+	if (_wait_for_bus(i2c_base))
    	return 1;
if (alen != 0) {
@@ -181,7 +136,7 @@ static int davinci_i2c_read(struct i2c_adapter *adap, uint8_t chip,
    	REG(&(i2c_base->i2c_sa)) = chip;
    	REG(&(i2c_base->i2c_con)) = tmp;
-		tmp = poll_i2c_irq(adap, I2C_STAT_XRDY | I2C_STAT_NACK);
+		tmp = _poll_i2c_irq(i2c_base, I2C_STAT_XRDY | I2C_STAT_NACK);
CHECK_NACK();
@@ -195,7 +150,8 @@ static int davinci_i2c_read(struct i2c_adapter *adap, uint8_t chip,
    			return 1;
    		}
-			tmp = poll_i2c_irq(adap, I2C_STAT_XRDY | I2C_STAT_NACK);
+			tmp = _poll_i2c_irq(i2c_base,
+					    I2C_STAT_XRDY | I2C_STAT_NACK);
CHECK_NACK();
    		/* No break, fall through */
@@ -208,8 +164,8 @@ static int davinci_i2c_read(struct i2c_adapter *adap, uint8_t chip,
    			return 1;
    		}
-			tmp = poll_i2c_irq(adap, I2C_STAT_XRDY |
-					   I2C_STAT_NACK | I2C_STAT_ARDY);
+			tmp = _poll_i2c_irq(i2c_base, I2C_STAT_XRDY |
+					    I2C_STAT_NACK | I2C_STAT_ARDY);
CHECK_NACK();
@@ -227,7 +183,7 @@ static int davinci_i2c_read(struct i2c_adapter *adap, uint8_t chip,
    REG(&(i2c_base->i2c_con)) = tmp;
for (i = 0; i < len; i++) {
-		tmp = poll_i2c_irq(adap, I2C_STAT_RRDY | I2C_STAT_NACK |
+		tmp = _poll_i2c_irq(i2c_base, I2C_STAT_RRDY | I2C_STAT_NACK |
    			   I2C_STAT_ROVR);
CHECK_NACK();
@@ -240,7 +196,7 @@ static int davinci_i2c_read(struct i2c_adapter *adap, uint8_t chip,
    	}
    }
-	tmp = poll_i2c_irq(adap, I2C_STAT_SCD | I2C_STAT_NACK);
+	tmp = _poll_i2c_irq(i2c_base, I2C_STAT_SCD | I2C_STAT_NACK);
CHECK_NACK();
@@ -249,7 +205,7 @@ static int davinci_i2c_read(struct i2c_adapter *adap, uint8_t chip,
    	return 1;
    }
-	flush_rx(adap);
+	_flush_rx(i2c_base);
    REG(&(i2c_base->i2c_stat)) = 0xffff;
    REG(&(i2c_base->i2c_cnt)) = 0;
    REG(&(i2c_base->i2c_con)) = 0;
@@ -257,10 +213,9 @@ static int davinci_i2c_read(struct i2c_adapter *adap, uint8_t chip,
    return 0;
 }
-static int davinci_i2c_write(struct i2c_adapter *adap, uint8_t chip,
-				uint32_t addr, int alen, uint8_t *buf, int len)
+static int _davinci_i2c_write(struct i2c_regs *i2c_base, uint8_t chip,
+			      uint32_t addr, int alen, uint8_t *buf, int len)
 {
-	struct i2c_regs *i2c_base = davinci_get_base(adap);
    uint32_t	tmp;
    int		i;
@@ -273,7 +228,7 @@ static int davinci_i2c_write(struct i2c_adapter *adap, uint8_t chip,
    	return 1;
    }
-	if (wait_for_bus(adap))
+	if (_wait_for_bus(i2c_base))
    	return 1;
/* Start address phase */
@@ -287,7 +242,7 @@ static int davinci_i2c_write(struct i2c_adapter *adap, uint8_t chip,
    switch (alen) {
    case 2:
    	/* Send address MSByte */
-		tmp = poll_i2c_irq(adap, I2C_STAT_XRDY | I2C_STAT_NACK);
+		tmp = _poll_i2c_irq(i2c_base, I2C_STAT_XRDY | I2C_STAT_NACK);
CHECK_NACK();
@@ -300,7 +255,7 @@ static int davinci_i2c_write(struct i2c_adapter *adap, uint8_t chip,
    	/* No break, fall through */
    case 1:
    	/* Send address LSByte */
-		tmp = poll_i2c_irq(adap, I2C_STAT_XRDY | I2C_STAT_NACK);
+		tmp = _poll_i2c_irq(i2c_base, I2C_STAT_XRDY | I2C_STAT_NACK);
CHECK_NACK();
@@ -313,7 +268,7 @@ static int davinci_i2c_write(struct i2c_adapter *adap, uint8_t chip,
    }
for (i = 0; i < len; i++) {
-		tmp = poll_i2c_irq(adap, I2C_STAT_XRDY | I2C_STAT_NACK);
+		tmp = _poll_i2c_irq(i2c_base, I2C_STAT_XRDY | I2C_STAT_NACK);
CHECK_NACK();
@@ -323,7 +278,7 @@ static int davinci_i2c_write(struct i2c_adapter *adap, uint8_t chip,
    		return 1;
    }
-	tmp = poll_i2c_irq(adap, I2C_STAT_SCD | I2C_STAT_NACK);
+	tmp = _poll_i2c_irq(i2c_base, I2C_STAT_SCD | I2C_STAT_NACK);
CHECK_NACK();
@@ -332,7 +287,7 @@ static int davinci_i2c_write(struct i2c_adapter *adap, uint8_t chip,
    	return 1;
    }
-	flush_rx(adap);
+	_flush_rx(i2c_base);
    REG(&(i2c_base->i2c_stat)) = 0xffff;
    REG(&(i2c_base->i2c_cnt)) = 0;
    REG(&(i2c_base->i2c_con)) = 0;
@@ -340,6 +295,42 @@ static int davinci_i2c_write(struct i2c_adapter *adap, uint8_t chip,
    return 0;
 }
+static int _davinci_i2c_probe_chip(struct i2c_regs *i2c_base, uint8_t chip)
+{
+	int	rc = 1;
+
+	if (chip == REG(&(i2c_base->i2c_oa)))
+		return rc;
+
+	REG(&(i2c_base->i2c_con)) = 0;
+	if (_wait_for_bus(i2c_base))
+		return 1;
+
+	/* try to read one byte from current (or only) address */
+	REG(&(i2c_base->i2c_cnt)) = 1;
+	REG(&(i2c_base->i2c_sa))  = chip;
+	REG(&(i2c_base->i2c_con)) = (I2C_CON_EN | I2C_CON_MST | I2C_CON_STT |
+				     I2C_CON_STP);
+	udelay(50000);
+
+	if (!(REG(&(i2c_base->i2c_stat)) & I2C_STAT_NACK)) {
+		rc = 0;
+		_flush_rx(i2c_base);
+		REG(&(i2c_base->i2c_stat)) = 0xffff;
+	} else {
+		REG(&(i2c_base->i2c_stat)) = 0xffff;
+		REG(&(i2c_base->i2c_con)) |= I2C_CON_STP;
+		udelay(20000);
+		if (_wait_for_bus(i2c_base))
+			return 1;
+	}
+
+	_flush_rx(i2c_base);
+	REG(&(i2c_base->i2c_stat)) = 0xffff;
+	REG(&(i2c_base->i2c_cnt)) = 0;
+	return rc;
+}
+
 static struct i2c_regs *davinci_get_base(struct i2c_adapter *adap)
 {
    switch (adap->hwadapnr) {
@@ -361,7 +352,51 @@ static struct i2c_regs *davinci_get_base(struct i2c_adapter *adap)
    return NULL;
 }
-U_BOOT_I2C_ADAP_COMPLETE(davinci_0, davinci_i2c_init, davinci_i2c_probe,
+static uint davinci_i2c_setspeed(struct i2c_adapter *adap, uint speed)
+{
+	struct i2c_regs *i2c_base = davinci_get_base(adap);
+	uint ret;
+
+	adap->speed = speed;
+	ret =  _davinci_i2c_setspeed(i2c_base, speed);
+
+	return ret;
+}
+
+static void davinci_i2c_init(struct i2c_adapter *adap, int speed,
+			     int slaveadd)
+{
+	struct i2c_regs *i2c_base = davinci_get_base(adap);
+
+	adap->speed = speed;
+	_davinci_i2c_init(i2c_base, speed, slaveadd);
+
+	return;
+}
+
+static int davinci_i2c_read(struct i2c_adapter *adap, uint8_t chip,
+			    uint32_t addr, int alen, uint8_t *buf, int len)
+{
+	struct i2c_regs *i2c_base = davinci_get_base(adap);
+	return _davinci_i2c_read(i2c_base, chip, addr, alen, buf, len);
+}
+
+static int davinci_i2c_write(struct i2c_adapter *adap, uint8_t chip,
+			     uint32_t addr, int alen, uint8_t *buf, int len)
+{
+	struct i2c_regs *i2c_base = davinci_get_base(adap);
+
+	return _davinci_i2c_write(i2c_base, chip, addr, alen, buf, len);
+}
+
+static int davinci_i2c_probe_chip(struct i2c_adapter *adap, uint8_t chip)
+{
+	struct i2c_regs *i2c_base = davinci_get_base(adap);
+
+	return _davinci_i2c_probe_chip(i2c_base, chip);
+}
+
+U_BOOT_I2C_ADAP_COMPLETE(davinci_0, davinci_i2c_init, davinci_i2c_probe_chip,
    		 davinci_i2c_read, davinci_i2c_write,
    		 davinci_i2c_setspeed,
    		 CONFIG_SYS_DAVINCI_I2C_SPEED,
@@ -369,7 +404,7 @@ U_BOOT_I2C_ADAP_COMPLETE(davinci_0, davinci_i2c_init, davinci_i2c_probe,
    		 0)
#if I2C_BUS_MAX >= 2
-U_BOOT_I2C_ADAP_COMPLETE(davinci_1, davinci_i2c_init, davinci_i2c_probe,
+U_BOOT_I2C_ADAP_COMPLETE(davinci_1, davinci_i2c_init, davinci_i2c_probe_chip,
    		 davinci_i2c_read, davinci_i2c_write,
    		 davinci_i2c_setspeed,
    		 CONFIG_SYS_DAVINCI_I2C_SPEED1,
@@ -378,7 +413,7 @@ U_BOOT_I2C_ADAP_COMPLETE(davinci_1, davinci_i2c_init, davinci_i2c_probe,
 #endif
#if I2C_BUS_MAX >= 3
-U_BOOT_I2C_ADAP_COMPLETE(davinci_2, davinci_i2c_init, davinci_i2c_probe,
+U_BOOT_I2C_ADAP_COMPLETE(davinci_2, davinci_i2c_init, davinci_i2c_probe_chip,
    		 davinci_i2c_read, davinci_i2c_write,
    		 davinci_i2c_setspeed,
    		 CONFIG_SYS_DAVINCI_I2C_SPEED2,
-- 
2.10.0


    