[PATCHv3] I2C: MV64XXX: Add Device Tree support

@@ -1,4 +1,4 @@
-* I2C
+* Marvell MMP I2C controller
 
 Required properties :
 

@@ -32,3 +32,22 @@ 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      : Te interrupt number
+ - clock-frequency : Desired I2C bus clock frequency in Hz.
+ - timeout-ms      : How long to wait for a transaction to complete
+
+Examples:
+
+	i2c at 11000 {
+		compatible = "marvell,mv64xxx-i2c";
+		reg = <0x11000 0x20>;
+		interrupts = <29>;
+		clock-frequency = <100000>;
+		timeout-ms = <1000>;
+	};

@@ -82,5 +82,16 @@
 			/* set partition map and/or chip-delay in board dts */
 			status = "disabled";
 		};
+
+		i2c at 11000 {
+			compatible = "marvell,mv64xxx-i2c";
+			reg = <0x11000 0x20>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+			interrupts = <29>;
+			clock-frequency = <400000>;
+			timeout-ms = <1000>;
+			status = "disable";
+		};
 	};
 };

@@ -28,6 +28,8 @@ static struct of_device_id kirkwood_dt_match_table[] __initdata = {
 
 struct of_dev_auxdata kirkwood_auxdata_lookup[] __initdata = {
 	OF_DEV_AUXDATA("marvell,orion-spi", 0xf1010600, "orion_spi.0", NULL),
+	OF_DEV_AUXDATA("marvell,mv64xxx-i2c", 0xf1011000, "mv64xxx_i2c.0",
+		       NULL),
 	{},
 };
 

@@ -17,6 +17,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/clk-provider.h>
 #include <linux/spinlock.h>
+#include <linux/mv643xx_i2c.h>
 #include <net/dsa.h>
 #include <asm/page.h>
 #include <asm/timex.h>

@@ -241,6 +242,7 @@ void __init kirkwood_clk_init(void)
 	orion_clkdev_add("0", "pcie", pex0);
 	orion_clkdev_add("1", "pcie", pex1);
 	orion_clkdev_add(NULL, "kirkwood-i2s", audio);
+	orion_clkdev_add(NULL, MV64XXX_I2C_CTLR_NAME ".0", runit);
 }
 
 /*****************************************************************************

@@ -47,6 +47,7 @@ void __init orion_clkdev_init(struct clk *tclk)
 	orion_clkdev_add(NULL, MV643XX_ETH_NAME ".2", tclk);
 	orion_clkdev_add(NULL, MV643XX_ETH_NAME ".3", tclk);
 	orion_clkdev_add(NULL, "orion_wdt", tclk);
+	orion_clkdev_add(NULL, MV64XXX_I2C_CTLR_NAME ".0", tclk);
 }
 
 /* Fill in the resources structure and link it into the platform

@@ -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 +103,7 @@ struct mv64xxx_i2c_data {
 	int			rc;
 	u32			freq_m;
 	u32			freq_n;
+	struct clk              *clk;
 	wait_queue_head_t	waitq;
 	spinlock_t		lock;
 	struct i2c_msg		*msg;

@@ -521,6 +527,36 @@ mv64xxx_i2c_unmap_regs(struct mv64xxx_i2c_data *drv_data)
 	drv_data->reg_base_p = 0;
 }
 
+#ifdef CONFIG_OF
+static int __devinit
+calc_freq(const int tclk, const int n, const int m)
+{
+	return tclk / (10 * (m + 1) * (2 << n));
+}
+
+static bool __devinit
+find_baud_factors(const int req_freq, const int tclk, int *best_n, int *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 = 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;
+}
+#endif
 static int __devinit
 mv64xxx_i2c_probe(struct platform_device *pd)
 {

@@ -528,7 +564,7 @@ mv64xxx_i2c_probe(struct platform_device *pd)
 	struct mv64xxx_i2c_pdata	*pdata = pd->dev.platform_data;
 	int	rc;
 
-	if ((pd->id != 0) || !pdata)
+	if ((!pdata && !pd->dev.of_node) || (pdata && (pd->id != 0)))
 		return -ENODEV;
 
 	drv_data = kzalloc(sizeof(struct mv64xxx_i2c_data), GFP_KERNEL);

@@ -546,19 +582,64 @@ 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);
+	}
+#ifdef CONFIG_OF
+	if (pd->dev.of_node) {
+		int bus_freq;
+		int tclk;
+		/* 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)
+		if (IS_ERR(drv_data->clk)) {
+			rc = -ENODEV;
+			goto exit_unmap_regs;
+		}
+		tclk = clk_get_rate(drv_data->clk);
+		of_property_read_u32(pd->dev.of_node, "clock-frequency",
+				     &bus_freq);
+		if (!find_baud_factors(bus_freq, tclk,
+				       &drv_data->freq_n, &drv_data->freq_m)) {
+			rc = -EINVAL;
+			goto exit_unmap_regs;
+		}
+		drv_data->irq = irq_of_parse_and_map(pd->dev.of_node, 0);
+#else
+		/* Have OF but no CLK */
+		rc = -ENODEV;
+		goto exit_unmap_regs;
+#endif
+	}
+#endif
 	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);
+	if (pd->dev.of_node)
+		drv_data->adapter.timeout = msecs_to_jiffies(
+			of_property_read_u32(pd->dev.of_node, "timeout-ms",
+					     &drv_data->freq_n));
+	else
+		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);
 

@@ -577,6 +658,8 @@ mv64xxx_i2c_probe(struct platform_device *pd)
 		goto exit_free_irq;
 	}
 
+	of_i2c_register_devices(&drv_data->adapter);
+
 	return 0;
 
 	exit_free_irq:

@@ -597,17 +680,31 @@ 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),
 	},
 };