Merge git://git.denx.de/u-boot-mpc85xx

[platform/kernel/u-boot.git] / drivers / i2c / omap24xx_i2c.c

diff --git a/drivers/i2c/omap24xx_i2c.c b/drivers/i2c/omap24xx_i2c.c
index 0006343..f71e0a5 100644 (file)
--- a/drivers/i2c/omap24xx_i2c.c
+++ b/drivers/i2c/omap24xx_i2c.c
@@ -64,36 +64,52 @@ struct omap_i2c {
 
 static int omap24_i2c_findpsc(u32 *pscl, u32 *psch, uint speed)
 {
-       unsigned int sampleclk, prescaler;
-       int fsscll, fssclh;
+       unsigned long internal_clk = 0, fclk;
+       unsigned int prescaler;
 
-       speed <<= 1;
-       prescaler = 0;
        /*
-        * some divisors may cause a precission loss, but shouldn't
-        * be a big thing, because i2c_clk is then allready very slow.
+        * This method is only called for Standard and Fast Mode speeds
+        *
+        * For some TI SoCs it is explicitly written in TRM (e,g, SPRUHZ6G,
+        * page 5685, Table 24-7)
+        * that the internal I2C clock (after prescaler) should be between
+        * 7-12 MHz (at least for Fast Mode (FS)).
+        *
+        * Such approach is used in v4.9 Linux kernel in:
+        * ./drivers/i2c/busses/i2c-omap.c (omap_i2c_init function).
         */
-       while (prescaler <= 0xFF) {
-               sampleclk = I2C_IP_CLK / (prescaler+1);
 
-               fsscll = sampleclk / speed;
-               fssclh = fsscll;
-               fsscll -= I2C_FASTSPEED_SCLL_TRIM;
-               fssclh -= I2C_FASTSPEED_SCLH_TRIM;
-
-               if (((fsscll > 0) && (fssclh > 0)) &&
-                   ((fsscll <= (255-I2C_FASTSPEED_SCLL_TRIM)) &&
-                   (fssclh <= (255-I2C_FASTSPEED_SCLH_TRIM)))) {
-                       if (pscl)
-                               *pscl = fsscll;
-                       if (psch)
-                               *psch = fssclh;
-
-                       return prescaler;
-               }
-               prescaler++;
+       speed /= 1000; /* convert speed to kHz */
+
+       if (speed > 100)
+               internal_clk = 9600;
+       else
+               internal_clk = 4000;
+
+       fclk = I2C_IP_CLK / 1000;
+       prescaler = fclk / internal_clk;
+       prescaler = prescaler - 1;
+
+       if (speed > 100) {
+               unsigned long scl;
+
+               /* Fast mode */
+               scl = internal_clk / speed;
+               *pscl = scl - (scl / 3) - I2C_FASTSPEED_SCLL_TRIM;
+               *psch = (scl / 3) - I2C_FASTSPEED_SCLH_TRIM;
+       } else {
+               /* Standard mode */
+               *pscl = internal_clk / (speed * 2) - I2C_FASTSPEED_SCLL_TRIM;
+               *psch = internal_clk / (speed * 2) - I2C_FASTSPEED_SCLH_TRIM;
        }
-       return -1;
+
+       debug("%s: speed [kHz]: %d psc: 0x%x sscl: 0x%x ssch: 0x%x\n",
+             __func__, speed, prescaler, *pscl, *psch);
+
+       if (*pscl <= 0 || *psch <= 0 || prescaler <= 0)
+               return -EINVAL;
+
+       return prescaler;
 }
 
 /*
@@ -106,7 +122,7 @@ static int wait_for_bb(struct i2c *i2c_base, int waitdelay)
        u16 stat;
 
        writew(0xFFFF, &i2c_base->stat);        /* clear current interrupts...*/
-#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX)
+#if defined(CONFIG_OMAP34XX)
        while ((stat = readw(&i2c_base->stat) & I2C_STAT_BB) && timeout--) {
 #else
        /* Read RAW status */
@@ -137,7 +153,7 @@ static u16 wait_for_event(struct i2c *i2c_base, int waitdelay)
 
        do {
                udelay(waitdelay);
-#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX)
+#if defined(CONFIG_OMAP34XX)
                status = readw(&i2c_base->stat);
 #else
                /* Read RAW status */
@@ -322,7 +338,7 @@ retry:
        /* own address */
        writew(slaveadd, &i2c_base->oa);
 
-#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX)
+#if defined(CONFIG_OMAP34XX)
        /*
         * Have to enable interrupts for OMAP2/3, these IPs don't have
         * an 'irqstatus_raw' register and we shall have to poll 'stat'
@@ -880,7 +896,7 @@ static int omap_i2c_ofdata_to_platdata(struct udevice *bus)
 {
        struct omap_i2c *priv = dev_get_priv(bus);
 
-       priv->regs = map_physmem(dev_get_addr(bus), sizeof(void *),
+       priv->regs = map_physmem(devfdt_get_addr(bus), sizeof(void *),
                                 MAP_NOCACHE);
        priv->speed = CONFIG_SYS_OMAP24_I2C_SPEED;
 
@@ -894,6 +910,7 @@ static const struct dm_i2c_ops omap_i2c_ops = {
 };
 
 static const struct udevice_id omap_i2c_ids[] = {
+       { .compatible = "ti,omap3-i2c" },
        { .compatible = "ti,omap4-i2c" },
        { }
 };