ARM: uniphier: add EHCI nodes for PH1-LD11

[oweals/u-boot.git] / drivers / i2c / i2c-cdns.c

diff --git a/drivers/i2c/i2c-cdns.c b/drivers/i2c/i2c-cdns.c
index 66bd580aad4b7185c5b1c029031abb292458f487..5642cd91fe2ee68bb1407f59b224d94bea302200 100644 (file)
--- a/drivers/i2c/i2c-cdns.c
+++ b/drivers/i2c/i2c-cdns.c
@@ -112,44 +112,10 @@ static void cdns_i2c_debug_status(struct cdns_i2c_regs *cdns_i2c)
 
 struct i2c_cdns_bus {
        int id;
+       unsigned int input_freq;
        struct cdns_i2c_regs __iomem *regs;     /* register base */
 };
 
-
-/** cdns_i2c_probe() - Probe method
- * @dev: udevice pointer
- *
- * DM callback called when device is probed
- */
-static int cdns_i2c_probe(struct udevice *dev)
-{
-       struct i2c_cdns_bus *bus = dev_get_priv(dev);
-
-       /* TODO: Calculate dividers based on CPU_CLK_1X */
-       /* 111MHz / ( (3 * 17) * 22 ) = ~100KHz */
-       writel((16 << CDNS_I2C_CONTROL_DIV_B_SHIFT) |
-               (2 << CDNS_I2C_CONTROL_DIV_A_SHIFT), &bus->regs->control);
-
-       /* Enable master mode, ack, and 7-bit addressing */
-       setbits_le32(&bus->regs->control, CDNS_I2C_CONTROL_MS |
-               CDNS_I2C_CONTROL_ACKEN | CDNS_I2C_CONTROL_NEA);
-
-       debug("%s bus %d at %p\n", __func__, dev->seq, bus->regs);
-
-       return 0;
-}
-
-static int cdns_i2c_remove(struct udevice *dev)
-{
-       struct i2c_cdns_bus *bus = dev_get_priv(dev);
-
-       debug("%s bus %d at %p\n", __func__, dev->seq, bus->regs);
-
-       unmap_sysmem(bus->regs);
-
-       return 0;
-}
-
 /* Wait for an interrupt */
 static u32 cdns_i2c_wait(struct cdns_i2c_regs *cdns_i2c, u32 mask)
 {
@@ -168,14 +134,84 @@ static u32 cdns_i2c_wait(struct cdns_i2c_regs *cdns_i2c, u32 mask)
        return int_status & mask;
 }
 
+#define CDNS_I2C_DIVA_MAX      4
+#define CDNS_I2C_DIVB_MAX      64
+
+static int cdns_i2c_calc_divs(unsigned long *f, unsigned long input_clk,
+               unsigned int *a, unsigned int *b)
+{
+       unsigned long fscl = *f, best_fscl = *f, actual_fscl, temp;
+       unsigned int div_a, div_b, calc_div_a = 0, calc_div_b = 0;
+       unsigned int last_error, current_error;
+
+       /* calculate (divisor_a+1) x (divisor_b+1) */
+       temp = input_clk / (22 * fscl);
+
+       /*
+        * If the calculated value is negative or 0CDNS_I2C_DIVA_MAX,
+        * the fscl input is out of range. Return error.
+        */
+       if (!temp || (temp > (CDNS_I2C_DIVA_MAX * CDNS_I2C_DIVB_MAX)))
+               return -EINVAL;
+
+       last_error = -1;
+       for (div_a = 0; div_a < CDNS_I2C_DIVA_MAX; div_a++) {
+               div_b = DIV_ROUND_UP(input_clk, 22 * fscl * (div_a + 1));
+
+               if ((div_b < 1) || (div_b > CDNS_I2C_DIVB_MAX))
+                       continue;
+               div_b--;
+
+               actual_fscl = input_clk / (22 * (div_a + 1) * (div_b + 1));
+
+               if (actual_fscl > fscl)
+                       continue;
+
+               current_error = ((actual_fscl > fscl) ? (actual_fscl - fscl) :
+                                                       (fscl - actual_fscl));
+
+               if (last_error > current_error) {
+                       calc_div_a = div_a;
+                       calc_div_b = div_b;
+                       best_fscl = actual_fscl;
+                       last_error = current_error;
+               }
+       }
+
+       *a = calc_div_a;
+       *b = calc_div_b;
+       *f = best_fscl;
+
+       return 0;
+}
+
 static int cdns_i2c_set_bus_speed(struct udevice *dev, unsigned int speed)
 {
-       if (speed != 100000) {
-               printf("%s, failed to set clock speed to %u\n", __func__,
-                      speed);
+       struct i2c_cdns_bus *bus = dev_get_priv(dev);
+       u32 div_a = 0, div_b = 0;
+       unsigned long speed_p = speed;
+       int ret = 0;
+
+       if (speed > 400000) {
+               debug("%s, failed to set clock speed to %u\n", __func__,
+                     speed);
                return -EINVAL;
        }
 
+       ret = cdns_i2c_calc_divs(&speed_p, bus->input_freq, &div_a, &div_b);
+       if (ret)
+               return ret;
+
+       debug("%s: div_a: %d, div_b: %d, input freq: %d, speed: %d/%ld\n",
+             __func__, div_a, div_b, bus->input_freq, speed, speed_p);
+
+       writel((div_b << CDNS_I2C_CONTROL_DIV_B_SHIFT) |
+              (div_a << CDNS_I2C_CONTROL_DIV_A_SHIFT), &bus->regs->control);
+
+       /* Enable master mode, ack, and 7-bit addressing */
+       setbits_le32(&bus->regs->control, CDNS_I2C_CONTROL_MS |
+               CDNS_I2C_CONTROL_ACKEN | CDNS_I2C_CONTROL_NEA);
+
        return 0;
 }
 
@@ -317,6 +353,8 @@ static int cdns_i2c_ofdata_to_platdata(struct udevice *dev)
        if (!i2c_bus->regs)
                return -ENOMEM;
 
+       i2c_bus->input_freq = 100000000; /* TODO hardcode input freq for now */
+
        return 0;
 }
 
@@ -335,8 +373,6 @@ U_BOOT_DRIVER(cdns_i2c) = {
        .name = "i2c-cdns",
        .id = UCLASS_I2C,
        .of_match = cdns_i2c_of_match,
-       .probe = cdns_i2c_probe,
-       .remove = cdns_i2c_remove,
        .ofdata_to_platdata = cdns_i2c_ofdata_to_platdata,
        .priv_auto_alloc_size = sizeof(struct i2c_cdns_bus),
        .ops = &cdns_i2c_ops,