> -----Original Message-----
> From: Ben Dooks [mailto:[email protected]]
> Sent: Tuesday, September 28, 2010 4:07 AM
> To: Nayak, Rajendra
> Cc: [email protected]; [email protected]; 
> [email protected]; [email protected];
> [email protected]; Kevin Hilman; Paul Walmsley
> Subject: Re: [PATCH v3 5/5] OMAP: I2C: Convert i2c driver to use PM runtime 
> api's
> 
> On Tue, Sep 21, 2010 at 07:37:16PM +0530, Rajendra Nayak wrote:
> > This patch converts the i2c driver to use PM runtime apis
> >
> > Signed-off-by: Rajendra Nayak <[email protected]>
> > Cc: Kevin Hilman <[email protected]>
> > Cc: Paul Walmsley <[email protected]>
> > ---
> >  drivers/i2c/busses/i2c-omap.c |   67 
> > +++++++++++++----------------------------
> >  1 files changed, 21 insertions(+), 46 deletions(-)
> >
> > diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
> > index 7674efb..126bde9 100644
> > --- a/drivers/i2c/busses/i2c-omap.c
> > +++ b/drivers/i2c/busses/i2c-omap.c
> > @@ -39,6 +39,7 @@
> >  #include <linux/io.h>
> >  #include <linux/slab.h>
> >  #include <linux/i2c-omap.h>
> > +#include <linux/pm_runtime.h>
> >
> >  /* I2C controller revisions */
> >  #define OMAP_I2C_REV_2                     0x20
> > @@ -175,8 +176,6 @@ struct omap_i2c_dev {
> >     void __iomem            *base;          /* virtual */
> >     int                     irq;
> >     int                     reg_shift;      /* bit shift for I2C register 
> > addresses */
> > -   struct clk              *iclk;          /* Interface clock */
> > -   struct clk              *fclk;          /* Functional clock */
> >     struct completion       cmd_complete;
> >     struct resource         *ioarea;
> >     u32                     latency;        /* maximum mpu wkup latency */
> > @@ -265,45 +264,18 @@ static inline u16 omap_i2c_read_reg(struct 
> > omap_i2c_dev *i2c_dev, int reg)
> >                             (i2c_dev->regs[reg] << i2c_dev->reg_shift));
> >  }
> >
> > -static int __init omap_i2c_get_clocks(struct omap_i2c_dev *dev)
> > +static void omap_i2c_unidle(struct omap_i2c_dev *dev)
> >  {
> > -   int ret;
> > +   struct platform_device *pdev;
> > +   struct omap_i2c_bus_platform_data *pdata;
> >
> > -   dev->iclk = clk_get(dev->dev, "ick");
> > -   if (IS_ERR(dev->iclk)) {
> > -           ret = PTR_ERR(dev->iclk);
> > -           dev->iclk = NULL;
> > -           return ret;
> > -   }
> > +   WARN_ON(!dev->idle);
> >
> > -   dev->fclk = clk_get(dev->dev, "fck");
> > -   if (IS_ERR(dev->fclk)) {
> > -           ret = PTR_ERR(dev->fclk);
> > -           if (dev->iclk != NULL) {
> > -                   clk_put(dev->iclk);
> > -                   dev->iclk = NULL;
> > -           }
> > -           dev->fclk = NULL;
> > -           return ret;
> > -   }
> > +   pdev = to_platform_device(dev->dev);
> > +   pdata = pdev->dev.platform_data;
> >
> > -   return 0;
> > -}
> > +   pm_runtime_get_sync(&pdev->dev);
> >
> > -static void omap_i2c_put_clocks(struct omap_i2c_dev *dev)
> > -{
> > -   clk_put(dev->fclk);
> > -   dev->fclk = NULL;
> > -   clk_put(dev->iclk);
> > -   dev->iclk = NULL;
> > -}
> > -
> > -static void omap_i2c_unidle(struct omap_i2c_dev *dev)
> > -{
> > -   WARN_ON(!dev->idle);
> > -
> > -   clk_enable(dev->iclk);
> > -   clk_enable(dev->fclk);
> >     if (cpu_is_omap34xx()) {
> >             omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
> >             omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, dev->pscstate);
> > @@ -326,10 +298,15 @@ static void omap_i2c_unidle(struct omap_i2c_dev *dev)
> >
> >  static void omap_i2c_idle(struct omap_i2c_dev *dev)
> >  {
> > +   struct platform_device *pdev;
> > +   struct omap_i2c_bus_platform_data *pdata;
> >     u16 iv;
> >
> >     WARN_ON(dev->idle);
> >
> > +   pdev = to_platform_device(dev->dev);
> > +   pdata = pdev->dev.platform_data;
> > +
> >     dev->iestate = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
> >     if (dev->rev >= OMAP_I2C_REV_ON_4430)
> >             omap_i2c_write_reg(dev, OMAP_I2C_IRQENABLE_CLR, 1);
> > @@ -345,8 +322,8 @@ static void omap_i2c_idle(struct omap_i2c_dev *dev)
> >             omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
> >     }
> >     dev->idle = 1;
> > -   clk_disable(dev->fclk);
> > -   clk_disable(dev->iclk);
> > +
> > +   pm_runtime_put_sync(&pdev->dev);
> >  }
> >
> >  static int omap_i2c_init(struct omap_i2c_dev *dev)
> > @@ -356,6 +333,7 @@ static int omap_i2c_init(struct omap_i2c_dev *dev)
> >     unsigned long fclk_rate = 12000000;
> >     unsigned long timeout;
> >     unsigned long internal_clk = 0;
> > +   struct clk *fclk;
> >
> >     if (dev->rev >= OMAP_I2C_REV_2) {
> >             /* Disable I2C controller before soft reset */
> > @@ -414,7 +392,8 @@ static int omap_i2c_init(struct omap_i2c_dev *dev)
> >              * always returns 12MHz for the functional clock, we can
> >              * do this bit unconditionally.
> >              */
> > -           fclk_rate = clk_get_rate(dev->fclk);
> > +           fclk = clk_get(dev->dev, "fck");
> > +           fclk_rate = clk_get_rate(fclk);
> >
> >             /* TRM for 5912 says the I2C clock must be prescaled to be
> >              * between 7 - 12 MHz. The XOR input clock is typically
> > @@ -443,7 +422,8 @@ static int omap_i2c_init(struct omap_i2c_dev *dev)
> >                     internal_clk = 9600;
> >             else
> >                     internal_clk = 4000;
> > -           fclk_rate = clk_get_rate(dev->fclk) / 1000;
> > +           fclk = clk_get(dev->dev, "fck");
> > +           fclk_rate = clk_get_rate(fclk) / 1000;
> 
> You don't put the clk after getting it and using it once?

clk_get needs an equivalent clk_put and not clk_get_rate. clk_get_rate
is used to merely know the existing rate of the clock.
 
> 
> >             /* Compute prescaler divisor */
> >             psc = fclk_rate / internal_clk;
> > @@ -1046,14 +1026,12 @@ omap_i2c_probe(struct platform_device *pdev)
> >     else
> >             dev->reg_shift = 2;
> >
> > -   if ((r = omap_i2c_get_clocks(dev)) != 0)
> > -           goto err_iounmap;
> > -
> >     if (cpu_is_omap44xx())
> >             dev->regs = (u8 *) omap4_reg_map;
> >     else
> >             dev->regs = (u8 *) reg_map;
> >
> > +   pm_runtime_enable(&pdev->dev);
> >     omap_i2c_unidle(dev);
> >
> >     dev->rev = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) & 0xff;
> > @@ -1125,8 +1103,6 @@ err_free_irq:
> >  err_unuse_clocks:
> >     omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
> >     omap_i2c_idle(dev);
> > -   omap_i2c_put_clocks(dev);
> > -err_iounmap:
> >     iounmap(dev->base);
> >  err_free_mem:
> >     platform_set_drvdata(pdev, NULL);
> > @@ -1148,7 +1124,6 @@ omap_i2c_remove(struct platform_device *pdev)
> >     free_irq(dev->irq, dev);
> >     i2c_del_adapter(&dev->adapter);
> >     omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
> > -   omap_i2c_put_clocks(dev);
> >     iounmap(dev->base);
> >     kfree(dev);
> >     mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > --
> > 1.5.4.7
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
> > the body of a message to [email protected]
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> 
> --
> --
> Ben
> 
> Q:      What's a light-year?
> A:      One-third less calories than a regular year.

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