2 files changed, 146 insertions, 6 deletions

diff --git a/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt b/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt
index b891ee218354..0f7945019f6f 100644
--- a/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt
+++ b/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt
@@ -1,4 +1,4 @@
-* I2C
+* Marvell MMP I2C controller
 
 Required properties :
 
@@ -32,3 +32,20 @@ Examples:
                 interrupts = <58>;
         };
 
+* Marvell MV64XXX I2C controller
+
+Required properties :
+
+ - reg             : Offset and length of the register set for the device
+ - compatible      : Should be "marvell,mv64xxx-i2c"
+ - interrupts      : The interrupt number
+ - clock-frequency : Desired I2C bus clock frequency in Hz.
+
+Examples:
+
+        i2c@11000 {
+                compatible = "marvell,mv64xxx-i2c";
+                reg = <0x11000 0x20>;
+                interrupts = <29>;
+                clock-frequency = <100000>;
+        };
diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c
index 6e70eea0cd2f..2e9d56719e99 100644
--- a/drivers/i2c/busses/i2c-mv64xxx.c
+++ b/drivers/i2c/busses/i2c-mv64xxx.c
@@ -18,6 +18,11 @@
 #include <linux/mv643xx_i2c.h>
 #include <linux/platform_device.h>
 #include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_i2c.h>
+#include <linux/clk.h>
+#include <linux/err.h>
 
 /* Register defines */
 #define MV64XXX_I2C_REG_SLAVE_ADDR                      0x00
@@ -98,6 +103,9 @@ struct mv64xxx_i2c_data {
         int                     rc;
         u32                     freq_m;
         u32                     freq_n;
+#if defined(CONFIG_HAVE_CLK)
+        struct clk              *clk;
+#endif
         wait_queue_head_t       waitq;
         spinlock_t              lock;
         struct i2c_msg          *msg;
@@ -521,6 +529,82 @@ mv64xxx_i2c_unmap_regs(struct mv64xxx_i2c_data *drv_data)
         drv_data->reg_base_p = 0;
 }
 
+#ifdef CONFIG_OF
+static int __devinit
+mv64xxx_calc_freq(const int tclk, const int n, const int m)
+{
+        return tclk / (10 * (m + 1) * (2 << n));
+}
+
+static bool __devinit
+mv64xxx_find_baud_factors(const u32 req_freq, const u32 tclk, u32 *best_n,
+                          u32 *best_m)
+{
+        int freq, delta, best_delta = INT_MAX;
+        int m, n;
+
+        for (n = 0; n <= 7; n++)
+                for (m = 0; m <= 15; m++) {
+                        freq = mv64xxx_calc_freq(tclk, n, m);
+                        delta = req_freq - freq;
+                        if (delta >= 0 && delta < best_delta) {
+                                *best_m = m;
+                                *best_n = n;
+                                best_delta = delta;
+                        }
+                        if (best_delta == 0)
+                                return true;
+                }
+        if (best_delta == INT_MAX)
+                return false;
+        return true;
+}
+
+static int __devinit
+mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data,
+                  struct device_node *np)
+{
+        u32 bus_freq, tclk;
+        int rc = 0;
+
+        /* CLK is mandatory when using DT to describe the i2c bus. We
+         * need to know tclk in order to calculate bus clock
+         * factors.
+         */
+#if !defined(CONFIG_HAVE_CLK)
+        /* Have OF but no CLK */
+        return -ENODEV;
+#else
+        if (IS_ERR(drv_data->clk)) {
+                rc = -ENODEV;
+                goto out;
+        }
+        tclk = clk_get_rate(drv_data->clk);
+        of_property_read_u32(np, "clock-frequency", &bus_freq);
+        if (!mv64xxx_find_baud_factors(bus_freq, tclk,
+                                       &drv_data->freq_n, &drv_data->freq_m)) {
+                rc = -EINVAL;
+                goto out;
+        }
+        drv_data->irq = irq_of_parse_and_map(np, 0);
+
+        /* Its not yet defined how timeouts will be specified in device tree.
+         * So hard code the value to 1 second.
+         */
+        drv_data->adapter.timeout = HZ;
+out:
+        return rc;
+#endif
+}
+#else /* CONFIG_OF */
+static int __devinit
+mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data,
+                  struct device_node *np)
+{
+        return -ENODEV;
+}
+#endif /* CONFIG_OF */
+
 static int __devinit
 mv64xxx_i2c_probe(struct platform_device *pd)
 {
@@ -528,7 +612,7 @@ mv64xxx_i2c_probe(struct platform_device *pd)
         struct mv64xxx_i2c_pdata        *pdata = pd->dev.platform_data;
         int     rc;
 
-        if (!pdata)
+        if ((!pdata && !pd->dev.of_node))
                 return -ENODEV;
 
         drv_data = kzalloc(sizeof(struct mv64xxx_i2c_data), GFP_KERNEL);
@@ -546,19 +630,35 @@ mv64xxx_i2c_probe(struct platform_device *pd)
         init_waitqueue_head(&drv_data->waitq);
         spin_lock_init(&drv_data->lock);
 
-        drv_data->freq_m = pdata->freq_m;
-        drv_data->freq_n = pdata->freq_n;
-        drv_data->irq = platform_get_irq(pd, 0);
+#if defined(CONFIG_HAVE_CLK)
+        /* Not all platforms have a clk */
+        drv_data->clk = clk_get(&pd->dev, NULL);
+        if (!IS_ERR(drv_data->clk)) {
+                clk_prepare(drv_data->clk);
+                clk_enable(drv_data->clk);
+        }
+#endif
+        if (pdata) {
+                drv_data->freq_m = pdata->freq_m;
+                drv_data->freq_n = pdata->freq_n;
+                drv_data->irq = platform_get_irq(pd, 0);
+                drv_data->adapter.timeout = msecs_to_jiffies(pdata->timeout);
+        } else if (pd->dev.of_node) {
+                rc = mv64xxx_of_config(drv_data, pd->dev.of_node);
+                if (rc)
+                        goto exit_unmap_regs;
+        }
         if (drv_data->irq < 0) {
                 rc = -ENXIO;
                 goto exit_unmap_regs;
         }
+
         drv_data->adapter.dev.parent = &pd->dev;
         drv_data->adapter.algo = &mv64xxx_i2c_algo;
         drv_data->adapter.owner = THIS_MODULE;
         drv_data->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
-        drv_data->adapter.timeout = msecs_to_jiffies(pdata->timeout);
         drv_data->adapter.nr = pd->id;
+        drv_data->adapter.dev.of_node = pd->dev.of_node;
         platform_set_drvdata(pd, drv_data);
         i2c_set_adapdata(&drv_data->adapter, drv_data);
 
@@ -577,11 +677,20 @@ mv64xxx_i2c_probe(struct platform_device *pd)
                 goto exit_free_irq;
         }
 
+        of_i2c_register_devices(&drv_data->adapter);
+
         return 0;
 
         exit_free_irq:
                 free_irq(drv_data->irq, drv_data);
         exit_unmap_regs:
+#if defined(CONFIG_HAVE_CLK)
+        /* Not all platforms have a clk */
+        if (!IS_ERR(drv_data->clk)) {
+                clk_disable(drv_data->clk);
+                clk_unprepare(drv_data->clk);
+        }
+#endif
                 mv64xxx_i2c_unmap_regs(drv_data);
         exit_kfree:
                 kfree(drv_data);
@@ -597,17 +706,31 @@ mv64xxx_i2c_remove(struct platform_device *dev)
         rc = i2c_del_adapter(&drv_data->adapter);
         free_irq(drv_data->irq, drv_data);
         mv64xxx_i2c_unmap_regs(drv_data);
+#if defined(CONFIG_HAVE_CLK)
+        /* Not all platforms have a clk */
+        if (!IS_ERR(drv_data->clk)) {
+                clk_disable(drv_data->clk);
+                clk_unprepare(drv_data->clk);
+        }
+#endif
         kfree(drv_data);
 
         return rc;
 }
 
+static const struct of_device_id mv64xxx_i2c_of_match_table[] __devinitdata = {
+        { .compatible = "marvell,mv64xxx-i2c", },
+        {}
+};
+MODULE_DEVICE_TABLE(of, mv64xxx_i2c_of_match_table);
+
 static struct platform_driver mv64xxx_i2c_driver = {
         .probe  = mv64xxx_i2c_probe,
         .remove = __devexit_p(mv64xxx_i2c_remove),
         .driver = {
                 .owner  = THIS_MODULE,
                 .name   = MV64XXX_I2C_CTLR_NAME,
+                .of_match_table = of_match_ptr(mv64xxx_i2c_of_match_table),
         },
 };