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i2c: davinci: Add cpufreq support

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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>
This commit is contained in:
Chaithrika U S 2010-01-06 14:55:00 +05:30 committed by Kevin Hilman
parent 68f15de976
commit 82c0de11b7
1 changed files with 63 additions and 0 deletions
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63
drivers/i2c/busses/i2c-davinci.c
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@ -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);