Hello.
Chaithrika U S wrote:
Add cpufreq support for DaVinci I2C driver.
Tested on DA850/OMAP-L138 EVM. For the purpose of testing, the patches
which add cpufreq support [1] for this SoC are needed.
[1]http://linux.davincidsp.com/pipermail/davinci-linux-open-source/
2009-September/016118.html
Signed-off-by: Chaithrika U S <[email protected]>
---
drivers/i2c/busses/i2c-davinci.c | 59 +++++++++++++++++++++++++++++++++++++-
1 files changed, 58 insertions(+), 1 deletions(-)
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
[...]
@@ -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
You should instead define this function as just returning 0 in the
#else branch above, so that #ifdef here can be avoided...
+
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
+
Same comment here. #ifdef's in the function code are frowned upon....
WBR, Sergei
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