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authorChaithrika U S <chaithrika@ti.com>2010-01-06 14:55:00 +0530
committerKevin Hilman <khilman@deeprootsystems.com>2010-08-05 09:38:32 -0700
commit82c0de11b734c5acec13c0f6007466da81cd16d9 (patch)
treec3e5c2a27ce5c67956040066ba0dbff7dca94e73 /drivers/i2c/busses/i2c-davinci.c
parent68f15de976f8f90d3bc0d10160aa20b0528760d4 (diff)
i2c: davinci: Add cpufreq support
Add cpufreq support for DaVinci I2C driver. Tested on DA850/OMAP-L138 EVM. Signed-off-by: Chaithrika U S <chaithrika@ti.com> Acked-by: Kevin Hilman <khilman@deeprootsystems.com>
Diffstat (limited to 'drivers/i2c/busses/i2c-davinci.c')
-rw-r--r--drivers/i2c/busses/i2c-davinci.c63
1 files changed, 63 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index 7afeb28d6d76..352b4e7bdd9e 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -36,6 +36,7 @@
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/slab.h>
+#include <linux/cpufreq.h>
#include <mach/hardware.h>
#include <mach/i2c.h>
@@ -107,6 +108,10 @@ struct davinci_i2c_dev {
int stop;
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 */
@@ -391,6 +396,11 @@ 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;
}
@@ -523,6 +533,48 @@ 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);
+}
+#else
+static inline int i2c_davinci_cpufreq_register(struct davinci_i2c_dev *dev)
+{
+ return 0;
+}
+
+static inline void i2c_davinci_cpufreq_deregister(struct davinci_i2c_dev *dev)
+{
+}
+#endif
+
static struct i2c_algorithm i2c_davinci_algo = {
.master_xfer = i2c_davinci_xfer,
.functionality = i2c_davinci_func,
@@ -562,6 +614,9 @@ 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);
@@ -587,6 +642,12 @@ static int davinci_i2c_probe(struct platform_device *pdev)
goto err_unuse_clocks;
}
+ r = i2c_davinci_cpufreq_register(dev);
+ if (r) {
+ dev_err(&pdev->dev, "failed to register cpufreq\n");
+ goto err_free_irq;
+ }
+
adap = &dev->adapter;
i2c_set_adapdata(adap, dev);
adap->owner = THIS_MODULE;
@@ -628,6 +689,8 @@ static int davinci_i2c_remove(struct platform_device *pdev)
struct davinci_i2c_dev *dev = platform_get_drvdata(pdev);
struct resource *mem;
+ i2c_davinci_cpufreq_deregister(dev);
+
platform_set_drvdata(pdev, NULL);
i2c_del_adapter(&dev->adapter);
put_device(&pdev->dev);