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Commit 82c0de11 authored by Chaithrika U S's avatar Chaithrika U S Committed by Kevin Hilman
Browse files

i2c: davinci: Add cpufreq support 



Add cpufreq support for DaVinci I2C driver.
Tested on DA850/OMAP-L138 EVM.

Signed-off-by: default avatarChaithrika U S <chaithrika@ti.com>
Acked-by: default avatarKevin Hilman <khilman@deeprootsystems.com>
parent 68f15de9

drivers/i2c/busses/i2c-davinci.c

+63 −0
Original line number Diff line number Diff line
@@ -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);