i2c: designware_i2c: Integrate set_speed() into dw_i2c_set_bus_speed()

[u-boot] / drivers / i2c / designware_i2c.c

diff --git a/drivers/i2c/designware_i2c.c b/drivers/i2c/designware_i2c.c
index e768cdedb0db99530eb9c9a34da290cf1191e0a4..035bf23dfcc730916f90090bbf606f49d3e169ce 100644 (file)
--- a/drivers/i2c/designware_i2c.c
+++ b/drivers/i2c/designware_i2c.c
@@ -34,23 +34,50 @@ static struct i2c_regs *i2c_get_base(struct i2c_adapter *adap)
        return NULL;
 }
 
+static void dw_i2c_enable(struct i2c_regs *i2c_base, bool enable)
+{
+       u32 ena = enable ? IC_ENABLE_0B : 0;
+       int timeout = 100;
+
+       do {
+               writel(ena, &i2c_base->ic_enable);
+               if ((readl(&i2c_base->ic_enable_status) & IC_ENABLE_0B) == ena)
+                       return;
+
+               /*
+                * Wait 10 times the signaling period of the highest I2C
+                * transfer supported by the driver (for 400KHz this is
+                * 25us) as described in the DesignWare I2C databook.
+                */
+               udelay(25);
+       } while (timeout--);
+
+       printf("timeout in %sabling I2C adapter\n", enable ? "en" : "dis");
+}
+
 /*
- * set_speed - Set the i2c speed mode (standard, high, fast)
- * @i2c_spd:   required i2c speed mode
+ * i2c_set_bus_speed - Set the i2c speed
+ * @speed:     required i2c speed
  *
- * Set the i2c speed mode (standard, high, fast)
+ * Set the i2c speed.
  */
-static void set_speed(struct i2c_adapter *adap, int i2c_spd)
+static unsigned int dw_i2c_set_bus_speed(struct i2c_adapter *adap,
+                                        unsigned int speed)
 {
        struct i2c_regs *i2c_base = i2c_get_base(adap);
        unsigned int cntl;
        unsigned int hcnt, lcnt;
-       unsigned int enbl;
+       int i2c_spd;
+
+       if (speed >= I2C_MAX_SPEED)
+               i2c_spd = IC_SPEED_MODE_MAX;
+       else if (speed >= I2C_FAST_SPEED)
+               i2c_spd = IC_SPEED_MODE_FAST;
+       else
+               i2c_spd = IC_SPEED_MODE_STANDARD;
 
        /* to set speed cltr must be disabled */
-       enbl = readl(&i2c_base->ic_enable);
-       enbl &= ~IC_ENABLE_0B;
-       writel(enbl, &i2c_base->ic_enable);
+       dw_i2c_enable(i2c_base, false);
 
        cntl = (readl(&i2c_base->ic_con) & (~IC_CON_SPD_MSK));
 
@@ -84,29 +111,8 @@ static void set_speed(struct i2c_adapter *adap, int i2c_spd)
        writel(cntl, &i2c_base->ic_con);
 
        /* Enable back i2c now speed set */
-       enbl |= IC_ENABLE_0B;
-       writel(enbl, &i2c_base->ic_enable);
-}
-
-/*
- * i2c_set_bus_speed - Set the i2c speed
- * @speed:     required i2c speed
- *
- * Set the i2c speed.
- */
-static unsigned int dw_i2c_set_bus_speed(struct i2c_adapter *adap,
-                                        unsigned int speed)
-{
-       int i2c_spd;
-
-       if (speed >= I2C_MAX_SPEED)
-               i2c_spd = IC_SPEED_MODE_MAX;
-       else if (speed >= I2C_FAST_SPEED)
-               i2c_spd = IC_SPEED_MODE_FAST;
-       else
-               i2c_spd = IC_SPEED_MODE_STANDARD;
+       dw_i2c_enable(i2c_base, true);
 
-       set_speed(adap, i2c_spd);
        adap->speed = speed;
 
        return 0;
@@ -123,12 +129,9 @@ static void dw_i2c_init(struct i2c_adapter *adap, int speed,
                        int slaveaddr)
 {
        struct i2c_regs *i2c_base = i2c_get_base(adap);
-       unsigned int enbl;
 
        /* Disable i2c */
-       enbl = readl(&i2c_base->ic_enable);
-       enbl &= ~IC_ENABLE_0B;
-       writel(enbl, &i2c_base->ic_enable);
+       dw_i2c_enable(i2c_base, false);
 
        writel((IC_CON_SD | IC_CON_SPD_FS | IC_CON_MM), &i2c_base->ic_con);
        writel(IC_RX_TL, &i2c_base->ic_rx_tl);
@@ -138,9 +141,7 @@ static void dw_i2c_init(struct i2c_adapter *adap, int speed,
        writel(slaveaddr, &i2c_base->ic_sar);
 
        /* Enable i2c */
-       enbl = readl(&i2c_base->ic_enable);
-       enbl |= IC_ENABLE_0B;
-       writel(enbl, &i2c_base->ic_enable);
+       dw_i2c_enable(i2c_base, true);
 }
 
 /*
@@ -152,19 +153,14 @@ static void dw_i2c_init(struct i2c_adapter *adap, int speed,
 static void i2c_setaddress(struct i2c_adapter *adap, unsigned int i2c_addr)
 {
        struct i2c_regs *i2c_base = i2c_get_base(adap);
-       unsigned int enbl;
 
        /* Disable i2c */
-       enbl = readl(&i2c_base->ic_enable);
-       enbl &= ~IC_ENABLE_0B;
-       writel(enbl, &i2c_base->ic_enable);
+       dw_i2c_enable(i2c_base, false);
 
        writel(i2c_addr, &i2c_base->ic_tar);
 
        /* Enable i2c */
-       enbl = readl(&i2c_base->ic_enable);
-       enbl |= IC_ENABLE_0B;
-       writel(enbl, &i2c_base->ic_enable);
+       dw_i2c_enable(i2c_base, true);
 }
 
 /*