[PATCH v3 5/5] OMAP: I2C: Convert i2c driver to use PM runtime api's
Nayak, Rajendra
rnayak at ti.com
Tue Sep 28 01:58:08 EDT 2010
> -----Original Message-----
> From: Ben Dooks [mailto:ben-i2c at fluff.org]
> Sent: Tuesday, September 28, 2010 4:07 AM
> To: Nayak, Rajendra
> Cc: linux-omap at vger.kernel.org; linux-arm-kernel at lists.infradead.org; linux-i2c at vger.kernel.org; ben-linux at fluff.org;
> khali at linux-fr.org; 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 <rnayak at ti.com>
> > Cc: Kevin Hilman <khilman at deeprootsystems.com>
> > Cc: Paul Walmsley <paul at pwsan.com>
> > ---
> > 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
> >
> > --
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>
> --
> --
> Ben
>
> Q: What's a light-year?
> A: One-third less calories than a regular year.
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