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[3/3] i2c: davinci: Add cpufreq support

Message ID 1260178136-26416-4-git-send-email-chaithrika@ti.com (mailing list archive)
State Superseded
Headers show

Commit Message

chaithrika@ti.com Dec. 7, 2009, 9:28 a.m. UTC
None
diff mbox

Patch

diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index 5f0888d..0f41da4 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -35,9 +35,9 @@ 
 #include <linux/interrupt.h>
 #include <linux/platform_device.h>
 #include <linux/io.h>
+#include <linux/cpufreq.h>
 
 #include <mach/hardware.h>
-
 #include <mach/i2c.h>
 
 /* ----- global defines ----------------------------------------------- */
@@ -114,6 +114,10 @@  struct davinci_i2c_dev {
 	int			irq;
 	u8			terminate;
 	struct i2c_adapter	adapter;
+#ifdef CONFIG_CPU_FREQ
+	struct completion	xfr_complete;
+	struct notifier_block	freq_transition;
+#endif
 };
 
 /* default platform data to use if not supplied in the platform_device */
@@ -384,6 +388,11 @@  i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 		if (ret < 0)
 			return ret;
 	}
+
+#ifdef CONFIG_CPU_FREQ
+	complete(&dev->xfr_complete);
+#endif
+
 	return num;
 }
 
@@ -508,6 +517,39 @@  static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id)
 	return count ? IRQ_HANDLED : IRQ_NONE;
 }
 
+#ifdef CONFIG_CPU_FREQ
+static int i2c_davinci_cpufreq_transition(struct notifier_block *nb,
+				     unsigned long val, void *data)
+{
+	struct davinci_i2c_dev *dev;
+
+	dev = container_of(nb, struct davinci_i2c_dev, freq_transition);
+	if (val == CPUFREQ_PRECHANGE) {
+		wait_for_completion(&dev->xfr_complete);
+		davinci_i2c_reset_ctrl(dev, 0);
+	} else if (val == CPUFREQ_POSTCHANGE) {
+		i2c_davinci_calc_clk_dividers(dev);
+		davinci_i2c_reset_ctrl(dev, 1);
+	}
+
+	return 0;
+}
+
+static inline int i2c_davinci_cpufreq_register(struct davinci_i2c_dev *dev)
+{
+	dev->freq_transition.notifier_call = i2c_davinci_cpufreq_transition;
+
+	return cpufreq_register_notifier(&dev->freq_transition,
+					 CPUFREQ_TRANSITION_NOTIFIER);
+}
+
+static inline void i2c_davinci_cpufreq_deregister(struct davinci_i2c_dev *dev)
+{
+	cpufreq_unregister_notifier(&dev->freq_transition,
+				    CPUFREQ_TRANSITION_NOTIFIER);
+}
+#endif
+
 static struct i2c_algorithm i2c_davinci_algo = {
 	.master_xfer	= i2c_davinci_xfer,
 	.functionality	= i2c_davinci_func,
@@ -547,6 +589,9 @@  static int davinci_i2c_probe(struct platform_device *pdev)
 	}
 
 	init_completion(&dev->cmd_complete);
+#ifdef CONFIG_CPU_FREQ
+	init_completion(&dev->xfr_complete);
+#endif
 	dev->dev = get_device(&pdev->dev);
 	dev->irq = irq->start;
 	platform_set_drvdata(pdev, dev);
@@ -567,6 +612,14 @@  static int davinci_i2c_probe(struct platform_device *pdev)
 		goto err_unuse_clocks;
 	}
 
+#ifdef CONFIG_CPU_FREQ
+	r = i2c_davinci_cpufreq_register(dev);
+	if (r) {
+		dev_err(&pdev->dev, "failed to register cpufreq\n");
+		goto err_free_irq;
+	}
+#endif
+
 	adap = &dev->adapter;
 	i2c_set_adapdata(adap, dev);
 	adap->owner = THIS_MODULE;
@@ -606,6 +659,10 @@  static int davinci_i2c_remove(struct platform_device *pdev)
 	struct davinci_i2c_dev *dev = platform_get_drvdata(pdev);
 	struct resource *mem;
 
+#ifdef CONFIG_CPU_FREQ
+	i2c_davinci_cpufreq_deregister(dev);
+#endif
+
 	platform_set_drvdata(pdev, NULL);
 	i2c_del_adapter(&dev->adapter);
 	put_device(&pdev->dev);