diff mbox

[PATCHv3] I2C: MV64XXX: Add Device Tree support

Message ID 1342430205-13702-2-git-send-email-andrew@lunn.ch (mailing list archive)
State New, archived
Headers show

Commit Message

Andrew Lunn July 16, 2012, 9:16 a.m. UTC
Extends the driver to get properties from device tree. Rather than
pass the N & M factors in DT, use the more standard clock-frequency
property. Calculate N & M at run time. In order to do this, we need to
know tclk. So the driver uses clk_get() etc in order to get the clock
and clk_get_rate() to determine the tclk rate. Not all platforms
however have CLK, so some #ifdefery is needed to ensure the driver
still compiles when CLK is not available.

Also extend the kirkwood DT support to supply the needed properties. A
default clock-frequency is 400KHz, which some platforms might need to
override to 100KHz if they have devices which do not support fast
mode.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@googlemail.com>
---
v2: Removed duplicate interrupt in DT.
v3: Use clock-frequency property, instead of explicit n & m baud factors.

i2c fix.
---
 Documentation/devicetree/bindings/i2c/mrvl-i2c.txt |   21 +++-
 arch/arm/boot/dts/kirkwood.dtsi                    |   11 ++
 arch/arm/mach-kirkwood/board-dt.c                  |    2 +
 arch/arm/mach-kirkwood/common.c                    |    2 +
 arch/arm/plat-orion/common.c                       |    1 +
 drivers/i2c/busses/i2c-mv64xxx.c                   |  107 +++++++++++++++++++-
 6 files changed, 138 insertions(+), 6 deletions(-)

Comments

Thomas Petazzoni July 16, 2012, 12:20 p.m. UTC | #1
Le Mon, 16 Jul 2012 11:16:45 +0200,
Andrew Lunn <andrew@lunn.ch> a écrit :

> + - reg             : Offset and length of the register set for the device
> + - compatible      : Should be "marvell,mv64xxx-i2c"
> + - interrupts      : Te interrupt number

                        The

> +		i2c@11000 {
> +			compatible = "marvell,mv64xxx-i2c";
> +			reg = <0x11000 0x20>;
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +			interrupts = <29>;
> +			clock-frequency = <400000>;
> +			timeout-ms = <1000>;
> +			status = "disable";

This should be "disabled". Any other status than "okay" is considered
as disabled, if I'm correct, but the right opposite to "okay" is
"disabled", as far as I'm aware.

The #ifdef machinery in the ->probe() function looks a bit ugly, but I
guess this can be cleaned up once all platforms using this driver will
have been converted to DT + clock framework.

Thomas
Andrew Lunn July 16, 2012, 12:37 p.m. UTC | #2
On Mon, Jul 16, 2012 at 02:20:19PM +0200, Thomas Petazzoni wrote:
> Le Mon, 16 Jul 2012 11:16:45 +0200,
> Andrew Lunn <andrew@lunn.ch> a ??crit :
> 
> > + - reg             : Offset and length of the register set for the device
> > + - compatible      : Should be "marvell,mv64xxx-i2c"
> > + - interrupts      : Te interrupt number
> 
>                         The
> 
> > +		i2c@11000 {
> > +			compatible = "marvell,mv64xxx-i2c";
> > +			reg = <0x11000 0x20>;
> > +			#address-cells = <1>;
> > +			#size-cells = <0>;
> > +			interrupts = <29>;
> > +			clock-frequency = <400000>;
> > +			timeout-ms = <1000>;
> > +			status = "disable";
> 
> This should be "disabled".

Thanks.

> The #ifdef machinery in the ->probe() function looks a bit ugly, but I
> guess this can be cleaned up once all platforms using this driver will
> have been converted to DT + clock framework.

Yes, it is ugly :-(

The ARM platforms are moving in the right direction. They all have
clock framework support and only mv78xx0 has nobody working on DT, as
far as i know.

I've no idea if anybody is still working on the powerpc platforms.
There are two _defconfig files that use it.

     Andrew
Wolfram Sang July 20, 2012, 10:35 a.m. UTC | #3
Hi Andrew,

On Mon, Jul 16, 2012 at 11:16:45AM +0200, Andrew Lunn wrote:
> Extends the driver to get properties from device tree. Rather than
> pass the N & M factors in DT, use the more standard clock-frequency
> property. Calculate N & M at run time. In order to do this, we need to

Thanks.

> know tclk. So the driver uses clk_get() etc in order to get the clock
> and clk_get_rate() to determine the tclk rate. Not all platforms
> however have CLK, so some #ifdefery is needed to ensure the driver
> still compiles when CLK is not available.
> 
> Also extend the kirkwood DT support to supply the needed properties. A
> default clock-frequency is 400KHz, which some platforms might need to
> override to 100KHz if they have devices which do not support fast
> mode.
> 
> Signed-off-by: Andrew Lunn <andrew@lunn.ch>
> Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@googlemail.com>

Has Sebastian acked THIS patch? Didn't saw such a mail? If it was a
previous patch which he acked, I'd like it to be resent, since the
divider calculation is new.

> ---
> v2: Removed duplicate interrupt in DT.
> v3: Use clock-frequency property, instead of explicit n & m baud factors.
> 
> i2c fix.
> ---
>  Documentation/devicetree/bindings/i2c/mrvl-i2c.txt |   21 +++-
>  arch/arm/boot/dts/kirkwood.dtsi                    |   11 ++
>  arch/arm/mach-kirkwood/board-dt.c                  |    2 +
>  arch/arm/mach-kirkwood/common.c                    |    2 +
>  arch/arm/plat-orion/common.c                       |    1 +
>  drivers/i2c/busses/i2c-mv64xxx.c                   |  107 +++++++++++++++++++-

As said in another mail, please split up arch/arm and i2c-stuff.

>  6 files changed, 138 insertions(+), 6 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt b/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt
> index b891ee2..885f340 100644
> --- a/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt
> +++ b/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt
> @@ -1,4 +1,4 @@
> -* I2C
> +* Marvell MMP I2C controller
>  
>  Required properties :
>  
> @@ -32,3 +32,22 @@ Examples:
>  		interrupts = <58>;
>  	};
>  
> +* Marvell MV64XXX I2C controller
> +
> +Required properties :
> +
> + - reg             : Offset and length of the register set for the device
> + - compatible      : Should be "marvell,mv64xxx-i2c"
> + - interrupts      : Te interrupt number
> + - clock-frequency : Desired I2C bus clock frequency in Hz.
> + - timeout-ms      : How long to wait for a transaction to complete

If you don't really need "timeout-ms", I'd ask you to drop it. I haven't
made up my mind how to handle those timeouts yet. They should be
per-slave and not per-bus, but the core cannot handle this yet. And even
though I am tempted to accept a per-bus-timeout, getting the binding
right is not something we can come up with before the next merge window.
I am suspecting a default value could do for now?

> +
> +Examples:
> +
> +	i2c@11000 {
> +		compatible = "marvell,mv64xxx-i2c";
> +		reg = <0x11000 0x20>;
> +		interrupts = <29>;
> +		clock-frequency = <100000>;
> +		timeout-ms = <1000>;
> +	};
> diff --git a/arch/arm/boot/dts/kirkwood.dtsi b/arch/arm/boot/dts/kirkwood.dtsi
> index a3350fd..bc57d81 100644
> --- a/arch/arm/boot/dts/kirkwood.dtsi
> +++ b/arch/arm/boot/dts/kirkwood.dtsi
> @@ -82,5 +82,16 @@
>  			/* set partition map and/or chip-delay in board dts */
>  			status = "disabled";
>  		};
> +
> +		i2c@11000 {
> +			compatible = "marvell,mv64xxx-i2c";
> +			reg = <0x11000 0x20>;
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +			interrupts = <29>;
> +			clock-frequency = <400000>;
> +			timeout-ms = <1000>;
> +			status = "disable";
> +		};
>  	};
>  };
> diff --git a/arch/arm/mach-kirkwood/board-dt.c b/arch/arm/mach-kirkwood/board-dt.c
> index 8f8da5d..24c8fdd 100644
> --- a/arch/arm/mach-kirkwood/board-dt.c
> +++ b/arch/arm/mach-kirkwood/board-dt.c
> @@ -28,6 +28,8 @@ static struct of_device_id kirkwood_dt_match_table[] __initdata = {
>  
>  struct of_dev_auxdata kirkwood_auxdata_lookup[] __initdata = {
>  	OF_DEV_AUXDATA("marvell,orion-spi", 0xf1010600, "orion_spi.0", NULL),
> +	OF_DEV_AUXDATA("marvell,mv64xxx-i2c", 0xf1011000, "mv64xxx_i2c.0",
> +		       NULL),
>  	{},
>  };
>  
> diff --git a/arch/arm/mach-kirkwood/common.c b/arch/arm/mach-kirkwood/common.c
> index f261cd2..078d9c6 100644
> --- a/arch/arm/mach-kirkwood/common.c
> +++ b/arch/arm/mach-kirkwood/common.c
> @@ -17,6 +17,7 @@
>  #include <linux/dma-mapping.h>
>  #include <linux/clk-provider.h>
>  #include <linux/spinlock.h>
> +#include <linux/mv643xx_i2c.h>
>  #include <net/dsa.h>
>  #include <asm/page.h>
>  #include <asm/timex.h>
> @@ -241,6 +242,7 @@ void __init kirkwood_clk_init(void)
>  	orion_clkdev_add("0", "pcie", pex0);
>  	orion_clkdev_add("1", "pcie", pex1);
>  	orion_clkdev_add(NULL, "kirkwood-i2s", audio);
> +	orion_clkdev_add(NULL, MV64XXX_I2C_CTLR_NAME ".0", runit);
>  }
>  
>  /*****************************************************************************
> diff --git a/arch/arm/plat-orion/common.c b/arch/arm/plat-orion/common.c
> index c179378..d245a87 100644
> --- a/arch/arm/plat-orion/common.c
> +++ b/arch/arm/plat-orion/common.c
> @@ -47,6 +47,7 @@ void __init orion_clkdev_init(struct clk *tclk)
>  	orion_clkdev_add(NULL, MV643XX_ETH_NAME ".2", tclk);
>  	orion_clkdev_add(NULL, MV643XX_ETH_NAME ".3", tclk);
>  	orion_clkdev_add(NULL, "orion_wdt", tclk);
> +	orion_clkdev_add(NULL, MV64XXX_I2C_CTLR_NAME ".0", tclk);
>  }
>  
>  /* Fill in the resources structure and link it into the platform
> diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c
> index 4f44a33..e97246b 100644
> --- a/drivers/i2c/busses/i2c-mv64xxx.c
> +++ b/drivers/i2c/busses/i2c-mv64xxx.c
> @@ -18,6 +18,11 @@
>  #include <linux/mv643xx_i2c.h>
>  #include <linux/platform_device.h>
>  #include <linux/io.h>
> +#include <linux/of.h>
> +#include <linux/of_irq.h>
> +#include <linux/of_i2c.h>
> +#include <linux/clk.h>
> +#include <linux/err.h>
>  
>  /* Register defines */
>  #define	MV64XXX_I2C_REG_SLAVE_ADDR			0x00
> @@ -98,6 +103,7 @@ struct mv64xxx_i2c_data {
>  	int			rc;
>  	u32			freq_m;
>  	u32			freq_n;
> +	struct clk              *clk;
>  	wait_queue_head_t	waitq;
>  	spinlock_t		lock;
>  	struct i2c_msg		*msg;
> @@ -521,6 +527,36 @@ mv64xxx_i2c_unmap_regs(struct mv64xxx_i2c_data *drv_data)
>  	drv_data->reg_base_p = 0;
>  }
>  
> +#ifdef CONFIG_OF

Hooray, we have one big CONFIG_OF block, so we could move other stuff
here? See below.

> +static int __devinit
> +calc_freq(const int tclk, const int n, const int m)
> +{
> +	return tclk / (10 * (m + 1) * (2 << n));
> +}
> +
> +static bool __devinit
> +find_baud_factors(const int req_freq, const int tclk, int *best_n, int *best_m)
> +{
> +	int freq, delta, best_delta = INT_MAX;
> +	int m, n;
> +
> +	for (n = 0; n <= 7; n++)
> +		for (m = 0; m <= 15; m++) {
> +			freq = calc_freq(tclk, n, m);
> +			delta = req_freq - freq;
> +			if (delta >= 0 && delta < best_delta) {
> +				*best_m = m;
> +				*best_n = n;
> +				best_delta = delta;
> +			}
> +			if (best_delta == 0)
> +				return true;
> +		}
> +	if (best_delta == INT_MAX)
> +		return false;
> +	return true;
> +}
> +#endif
>  static int __devinit
>  mv64xxx_i2c_probe(struct platform_device *pd)
>  {
> @@ -528,7 +564,7 @@ mv64xxx_i2c_probe(struct platform_device *pd)
>  	struct mv64xxx_i2c_pdata	*pdata = pd->dev.platform_data;
>  	int	rc;
>  
> -	if ((pd->id != 0) || !pdata)
> +	if ((!pdata && !pd->dev.of_node) || (pdata && (pd->id != 0)))
>  		return -ENODEV;

(extra points if you rebase your patch on top of this patch
d61a9095155e832287552a9e565b8756ee293c46 from my next tree:
git://git.pengutronix.de/git/wsa/linux.git i2c-embedded/for-next)

>  
>  	drv_data = kzalloc(sizeof(struct mv64xxx_i2c_data), GFP_KERNEL);
> @@ -546,19 +582,64 @@ mv64xxx_i2c_probe(struct platform_device *pd)
>  	init_waitqueue_head(&drv_data->waitq);
>  	spin_lock_init(&drv_data->lock);
>  
> -	drv_data->freq_m = pdata->freq_m;
> -	drv_data->freq_n = pdata->freq_n;
> -	drv_data->irq = platform_get_irq(pd, 0);
> +#if defined(CONFIG_HAVE_CLK)
> +	/* Not all platforms have a clk */
> +	drv_data->clk = clk_get(&pd->dev, NULL);
> +	if (!IS_ERR(drv_data->clk)) {
> +		clk_prepare(drv_data->clk);
> +		clk_enable(drv_data->clk);
> +	}

Call this code only when CONFIG_OF?

> +#endif
> +	if (pdata) {
> +		drv_data->freq_m = pdata->freq_m;
> +		drv_data->freq_n = pdata->freq_n;
> +		drv_data->irq = platform_get_irq(pd, 0);
> +	}
> +#ifdef CONFIG_OF
> +	if (pd->dev.of_node) {

Move this stuff into a seperate function and put it into the big
CONFIG_OF block? That should make the code a lot more readable?

> +		int bus_freq;
> +		int tclk;
> +		/* CLK is mandatory when using DT to describe the i2c
> +		 * bus. We need to know tclk in order to calculate bus
> +		 * clock factors. */
> +#if defined(CONFIG_HAVE_CLK)
> +		if (IS_ERR(drv_data->clk)) {
> +			rc = -ENODEV;
> +			goto exit_unmap_regs;
> +		}
> +		tclk = clk_get_rate(drv_data->clk);
> +		of_property_read_u32(pd->dev.of_node, "clock-frequency",
> +				     &bus_freq);
> +		if (!find_baud_factors(bus_freq, tclk,
> +				       &drv_data->freq_n, &drv_data->freq_m)) {
> +			rc = -EINVAL;
> +			goto exit_unmap_regs;
> +		}
> +		drv_data->irq = irq_of_parse_and_map(pd->dev.of_node, 0);
> +#else
> +		/* Have OF but no CLK */
> +		rc = -ENODEV;
> +		goto exit_unmap_regs;
> +#endif
> +	}
> +#endif
>  	if (drv_data->irq < 0) {
>  		rc = -ENXIO;
>  		goto exit_unmap_regs;
>  	}
> +
>  	drv_data->adapter.dev.parent = &pd->dev;
>  	drv_data->adapter.algo = &mv64xxx_i2c_algo;
>  	drv_data->adapter.owner = THIS_MODULE;
>  	drv_data->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
> -	drv_data->adapter.timeout = msecs_to_jiffies(pdata->timeout);
> +	if (pd->dev.of_node)
> +		drv_data->adapter.timeout = msecs_to_jiffies(
> +			of_property_read_u32(pd->dev.of_node, "timeout-ms",
> +					     &drv_data->freq_n));
> +	else
> +		drv_data->adapter.timeout = msecs_to_jiffies(pdata->timeout);

This should also go into the new function.

>  	drv_data->adapter.nr = pd->id;
> +	drv_data->adapter.dev.of_node = pd->dev.of_node;
>  	platform_set_drvdata(pd, drv_data);
>  	i2c_set_adapdata(&drv_data->adapter, drv_data);
>  
> @@ -577,6 +658,8 @@ mv64xxx_i2c_probe(struct platform_device *pd)
>  		goto exit_free_irq;
>  	}
>  
> +	of_i2c_register_devices(&drv_data->adapter);
> +
>  	return 0;
>  
>  	exit_free_irq:
> @@ -597,17 +680,31 @@ mv64xxx_i2c_remove(struct platform_device *dev)
>  	rc = i2c_del_adapter(&drv_data->adapter);
>  	free_irq(drv_data->irq, drv_data);
>  	mv64xxx_i2c_unmap_regs(drv_data);
> +#if defined(CONFIG_HAVE_CLK)
> +	/* Not all platforms have a clk */
> +	if (!IS_ERR(drv_data->clk)) {
> +		clk_disable(drv_data->clk);
> +		clk_unprepare(drv_data->clk);
> +	}
> +#endif
>  	kfree(drv_data);
>  
>  	return rc;
>  }
>  
> +static const struct of_device_id mv64xxx_i2c_of_match_table[] __devinitdata = {
> +	{ .compatible = "marvell,mv64xxx-i2c", },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, mv64xxx_i2c_of_match_table);
> +
>  static struct platform_driver mv64xxx_i2c_driver = {
>  	.probe	= mv64xxx_i2c_probe,
>  	.remove	= __devexit_p(mv64xxx_i2c_remove),
>  	.driver	= {
>  		.owner	= THIS_MODULE,
>  		.name	= MV64XXX_I2C_CTLR_NAME,
> +		.of_match_table = of_match_ptr(mv64xxx_i2c_of_match_table),
>  	},
>  };
>  
> -- 
> 1.7.10
>
Andrew Lunn July 20, 2012, 11:17 a.m. UTC | #4
On Fri, Jul 20, 2012 at 12:35:13PM +0200, Wolfram Sang wrote:
> Hi Andrew,
> 
> On Mon, Jul 16, 2012 at 11:16:45AM +0200, Andrew Lunn wrote:
> > Extends the driver to get properties from device tree. Rather than
> > pass the N & M factors in DT, use the more standard clock-frequency
> > property. Calculate N & M at run time. In order to do this, we need to
> 
> Thanks.
> 
> > know tclk. So the driver uses clk_get() etc in order to get the clock
> > and clk_get_rate() to determine the tclk rate. Not all platforms
> > however have CLK, so some #ifdefery is needed to ensure the driver
> > still compiles when CLK is not available.
> > 
> > Also extend the kirkwood DT support to supply the needed properties. A
> > default clock-frequency is 400KHz, which some platforms might need to
> > override to 100KHz if they have devices which do not support fast
> > mode.
> > 
> > Signed-off-by: Andrew Lunn <andrew@lunn.ch>
> > Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@googlemail.com>
> 
> Has Sebastian acked THIS patch? Didn't saw such a mail? If it was a
> previous patch which he acked, I'd like it to be resent, since the
> divider calculation is new.

Yes and the version that came after it, fixing the timeout code, which
at your request i will rip out. It has also been tested by a couple of
other people on different kirkwood boards.

> > v2: Removed duplicate interrupt in DT.
> > v3: Use clock-frequency property, instead of explicit n & m baud factors.
> > 
> > i2c fix.
> > ---
> >  Documentation/devicetree/bindings/i2c/mrvl-i2c.txt |   21 +++-
> >  arch/arm/boot/dts/kirkwood.dtsi                    |   11 ++
> >  arch/arm/mach-kirkwood/board-dt.c                  |    2 +
> >  arch/arm/mach-kirkwood/common.c                    |    2 +
> >  arch/arm/plat-orion/common.c                       |    1 +
> >  drivers/i2c/busses/i2c-mv64xxx.c                   |  107 +++++++++++++++++++-
> 
> As said in another mail, please split up arch/arm and i2c-stuff.

Sure, no problem. 

> 
> > +Required properties :
> > +
> > + - reg             : Offset and length of the register set for the device
> > + - compatible      : Should be "marvell,mv64xxx-i2c"
> > + - interrupts      : Te interrupt number
> > + - clock-frequency : Desired I2C bus clock frequency in Hz.
> > + - timeout-ms      : How long to wait for a transaction to complete
> 
> If you don't really need "timeout-ms", I'd ask you to drop it.

I can hard code it to 1 second. This should have no impact on any
plat-orion boards, since they all use 1 second.

> > +#ifdef CONFIG_OF
> 
> Hooray, we have one big CONFIG_OF block, so we could move other stuff
> here? See below.
> 
> > +static int __devinit
> > +calc_freq(const int tclk, const int n, const int m)
> > +{
> > +	return tclk / (10 * (m + 1) * (2 << n));
> > +}
> > +
> > +static bool __devinit
> > +find_baud_factors(const int req_freq, const int tclk, int *best_n, int *best_m)
> > +{
> > +	int freq, delta, best_delta = INT_MAX;
> > +	int m, n;
> > +
> > +	for (n = 0; n <= 7; n++)
> > +		for (m = 0; m <= 15; m++) {
> > +			freq = calc_freq(tclk, n, m);
> > +			delta = req_freq - freq;
> > +			if (delta >= 0 && delta < best_delta) {
> > +				*best_m = m;
> > +				*best_n = n;
> > +				best_delta = delta;
> > +			}
> > +			if (best_delta == 0)
> > +				return true;
> > +		}
> > +	if (best_delta == INT_MAX)
> > +		return false;
> > +	return true;
> > +}
> > +#endif
> >  static int __devinit
> >  mv64xxx_i2c_probe(struct platform_device *pd)
> >  {
> > @@ -528,7 +564,7 @@ mv64xxx_i2c_probe(struct platform_device *pd)
> >  	struct mv64xxx_i2c_pdata	*pdata = pd->dev.platform_data;
> >  	int	rc;
> >  
> > -	if ((pd->id != 0) || !pdata)
> > +	if ((!pdata && !pd->dev.of_node) || (pdata && (pd->id != 0)))
> >  		return -ENODEV;
> 
> (extra points if you rebase your patch on top of this patch
> d61a9095155e832287552a9e565b8756ee293c46 from my next tree:
> git://git.pengutronix.de/git/wsa/linux.git i2c-embedded/for-next)

Yes, i know of this patch from Florian Fainelli. I was planning on
warning you about the merge conflict, but maybe i will try for the
rebase.

> >  	drv_data = kzalloc(sizeof(struct mv64xxx_i2c_data), GFP_KERNEL);
> > @@ -546,19 +582,64 @@ mv64xxx_i2c_probe(struct platform_device *pd)
> >  	init_waitqueue_head(&drv_data->waitq);
> >  	spin_lock_init(&drv_data->lock);
> >  
> > -	drv_data->freq_m = pdata->freq_m;
> > -	drv_data->freq_n = pdata->freq_n;
> > -	drv_data->irq = platform_get_irq(pd, 0);
> > +#if defined(CONFIG_HAVE_CLK)
> > +	/* Not all platforms have a clk */
> > +	drv_data->clk = clk_get(&pd->dev, NULL);
> > +	if (!IS_ERR(drv_data->clk)) {
> > +		clk_prepare(drv_data->clk);
> > +		clk_enable(drv_data->clk);
> > +	}
> 
> Call this code only when CONFIG_OF?

Nope. There are lots of kirkwood boards who need to turn this clock
on, but are not yet converted to DT. I suspect Dove is similar. I also
don't particularly like all this #ifdefery, but there is not much i
can do about it :-(

> 
> > +#endif
> > +	if (pdata) {
> > +		drv_data->freq_m = pdata->freq_m;
> > +		drv_data->freq_n = pdata->freq_n;
> > +		drv_data->irq = platform_get_irq(pd, 0);
> > +	}
> > +#ifdef CONFIG_OF
> > +	if (pd->dev.of_node) {
> 
> Move this stuff into a seperate function and put it into the big
> CONFIG_OF block? That should make the code a lot more readable?

O.K.
 
> > +		int bus_freq;
> > +		int tclk;
> > +		/* CLK is mandatory when using DT to describe the i2c
> > +		 * bus. We need to know tclk in order to calculate bus
> > +		 * clock factors. */
> > +#if defined(CONFIG_HAVE_CLK)
> > +		if (IS_ERR(drv_data->clk)) {
> > +			rc = -ENODEV;
> > +			goto exit_unmap_regs;
> > +		}
> > +		tclk = clk_get_rate(drv_data->clk);
> > +		of_property_read_u32(pd->dev.of_node, "clock-frequency",
> > +				     &bus_freq);
> > +		if (!find_baud_factors(bus_freq, tclk,
> > +				       &drv_data->freq_n, &drv_data->freq_m)) {
> > +			rc = -EINVAL;
> > +			goto exit_unmap_regs;
> > +		}
> > +		drv_data->irq = irq_of_parse_and_map(pd->dev.of_node, 0);
> > +#else
> > +		/* Have OF but no CLK */
> > +		rc = -ENODEV;
> > +		goto exit_unmap_regs;
> > +#endif
> > +	}
> > +#endif
> >  	if (drv_data->irq < 0) {
> >  		rc = -ENXIO;
> >  		goto exit_unmap_regs;
> >  	}
> > +
> >  	drv_data->adapter.dev.parent = &pd->dev;
> >  	drv_data->adapter.algo = &mv64xxx_i2c_algo;
> >  	drv_data->adapter.owner = THIS_MODULE;
> >  	drv_data->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
> > -	drv_data->adapter.timeout = msecs_to_jiffies(pdata->timeout);
> > +	if (pd->dev.of_node)
> > +		drv_data->adapter.timeout = msecs_to_jiffies(
> > +			of_property_read_u32(pd->dev.of_node, "timeout-ms",
> > +					     &drv_data->freq_n));
> > +	else
> > +		drv_data->adapter.timeout = msecs_to_jiffies(pdata->timeout);
> 
> This should also go into the new function.

Actually, its totally broken, and is what i will replace with a hard
coded value...

      Andrew
diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt b/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt
index b891ee2..885f340 100644
--- a/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt
+++ b/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt
@@ -1,4 +1,4 @@ 
-* I2C
+* Marvell MMP I2C controller
 
 Required properties :
 
@@ -32,3 +32,22 @@  Examples:
 		interrupts = <58>;
 	};
 
+* Marvell MV64XXX I2C controller
+
+Required properties :
+
+ - reg             : Offset and length of the register set for the device
+ - compatible      : Should be "marvell,mv64xxx-i2c"
+ - interrupts      : Te interrupt number
+ - clock-frequency : Desired I2C bus clock frequency in Hz.
+ - timeout-ms      : How long to wait for a transaction to complete
+
+Examples:
+
+	i2c@11000 {
+		compatible = "marvell,mv64xxx-i2c";
+		reg = <0x11000 0x20>;
+		interrupts = <29>;
+		clock-frequency = <100000>;
+		timeout-ms = <1000>;
+	};
diff --git a/arch/arm/boot/dts/kirkwood.dtsi b/arch/arm/boot/dts/kirkwood.dtsi
index a3350fd..bc57d81 100644
--- a/arch/arm/boot/dts/kirkwood.dtsi
+++ b/arch/arm/boot/dts/kirkwood.dtsi
@@ -82,5 +82,16 @@ 
 			/* set partition map and/or chip-delay in board dts */
 			status = "disabled";
 		};
+
+		i2c@11000 {
+			compatible = "marvell,mv64xxx-i2c";
+			reg = <0x11000 0x20>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+			interrupts = <29>;
+			clock-frequency = <400000>;
+			timeout-ms = <1000>;
+			status = "disable";
+		};
 	};
 };
diff --git a/arch/arm/mach-kirkwood/board-dt.c b/arch/arm/mach-kirkwood/board-dt.c
index 8f8da5d..24c8fdd 100644
--- a/arch/arm/mach-kirkwood/board-dt.c
+++ b/arch/arm/mach-kirkwood/board-dt.c
@@ -28,6 +28,8 @@  static struct of_device_id kirkwood_dt_match_table[] __initdata = {
 
 struct of_dev_auxdata kirkwood_auxdata_lookup[] __initdata = {
 	OF_DEV_AUXDATA("marvell,orion-spi", 0xf1010600, "orion_spi.0", NULL),
+	OF_DEV_AUXDATA("marvell,mv64xxx-i2c", 0xf1011000, "mv64xxx_i2c.0",
+		       NULL),
 	{},
 };
 
diff --git a/arch/arm/mach-kirkwood/common.c b/arch/arm/mach-kirkwood/common.c
index f261cd2..078d9c6 100644
--- a/arch/arm/mach-kirkwood/common.c
+++ b/arch/arm/mach-kirkwood/common.c
@@ -17,6 +17,7 @@ 
 #include <linux/dma-mapping.h>
 #include <linux/clk-provider.h>
 #include <linux/spinlock.h>
+#include <linux/mv643xx_i2c.h>
 #include <net/dsa.h>
 #include <asm/page.h>
 #include <asm/timex.h>
@@ -241,6 +242,7 @@  void __init kirkwood_clk_init(void)
 	orion_clkdev_add("0", "pcie", pex0);
 	orion_clkdev_add("1", "pcie", pex1);
 	orion_clkdev_add(NULL, "kirkwood-i2s", audio);
+	orion_clkdev_add(NULL, MV64XXX_I2C_CTLR_NAME ".0", runit);
 }
 
 /*****************************************************************************
diff --git a/arch/arm/plat-orion/common.c b/arch/arm/plat-orion/common.c
index c179378..d245a87 100644
--- a/arch/arm/plat-orion/common.c
+++ b/arch/arm/plat-orion/common.c
@@ -47,6 +47,7 @@  void __init orion_clkdev_init(struct clk *tclk)
 	orion_clkdev_add(NULL, MV643XX_ETH_NAME ".2", tclk);
 	orion_clkdev_add(NULL, MV643XX_ETH_NAME ".3", tclk);
 	orion_clkdev_add(NULL, "orion_wdt", tclk);
+	orion_clkdev_add(NULL, MV64XXX_I2C_CTLR_NAME ".0", tclk);
 }
 
 /* Fill in the resources structure and link it into the platform
diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c
index 4f44a33..e97246b 100644
--- a/drivers/i2c/busses/i2c-mv64xxx.c
+++ b/drivers/i2c/busses/i2c-mv64xxx.c
@@ -18,6 +18,11 @@ 
 #include <linux/mv643xx_i2c.h>
 #include <linux/platform_device.h>
 #include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_i2c.h>
+#include <linux/clk.h>
+#include <linux/err.h>
 
 /* Register defines */
 #define	MV64XXX_I2C_REG_SLAVE_ADDR			0x00
@@ -98,6 +103,7 @@  struct mv64xxx_i2c_data {
 	int			rc;
 	u32			freq_m;
 	u32			freq_n;
+	struct clk              *clk;
 	wait_queue_head_t	waitq;
 	spinlock_t		lock;
 	struct i2c_msg		*msg;
@@ -521,6 +527,36 @@  mv64xxx_i2c_unmap_regs(struct mv64xxx_i2c_data *drv_data)
 	drv_data->reg_base_p = 0;
 }
 
+#ifdef CONFIG_OF
+static int __devinit
+calc_freq(const int tclk, const int n, const int m)
+{
+	return tclk / (10 * (m + 1) * (2 << n));
+}
+
+static bool __devinit
+find_baud_factors(const int req_freq, const int tclk, int *best_n, int *best_m)
+{
+	int freq, delta, best_delta = INT_MAX;
+	int m, n;
+
+	for (n = 0; n <= 7; n++)
+		for (m = 0; m <= 15; m++) {
+			freq = calc_freq(tclk, n, m);
+			delta = req_freq - freq;
+			if (delta >= 0 && delta < best_delta) {
+				*best_m = m;
+				*best_n = n;
+				best_delta = delta;
+			}
+			if (best_delta == 0)
+				return true;
+		}
+	if (best_delta == INT_MAX)
+		return false;
+	return true;
+}
+#endif
 static int __devinit
 mv64xxx_i2c_probe(struct platform_device *pd)
 {
@@ -528,7 +564,7 @@  mv64xxx_i2c_probe(struct platform_device *pd)
 	struct mv64xxx_i2c_pdata	*pdata = pd->dev.platform_data;
 	int	rc;
 
-	if ((pd->id != 0) || !pdata)
+	if ((!pdata && !pd->dev.of_node) || (pdata && (pd->id != 0)))
 		return -ENODEV;
 
 	drv_data = kzalloc(sizeof(struct mv64xxx_i2c_data), GFP_KERNEL);
@@ -546,19 +582,64 @@  mv64xxx_i2c_probe(struct platform_device *pd)
 	init_waitqueue_head(&drv_data->waitq);
 	spin_lock_init(&drv_data->lock);
 
-	drv_data->freq_m = pdata->freq_m;
-	drv_data->freq_n = pdata->freq_n;
-	drv_data->irq = platform_get_irq(pd, 0);
+#if defined(CONFIG_HAVE_CLK)
+	/* Not all platforms have a clk */
+	drv_data->clk = clk_get(&pd->dev, NULL);
+	if (!IS_ERR(drv_data->clk)) {
+		clk_prepare(drv_data->clk);
+		clk_enable(drv_data->clk);
+	}
+#endif
+	if (pdata) {
+		drv_data->freq_m = pdata->freq_m;
+		drv_data->freq_n = pdata->freq_n;
+		drv_data->irq = platform_get_irq(pd, 0);
+	}
+#ifdef CONFIG_OF
+	if (pd->dev.of_node) {
+		int bus_freq;
+		int tclk;
+		/* CLK is mandatory when using DT to describe the i2c
+		 * bus. We need to know tclk in order to calculate bus
+		 * clock factors. */
+#if defined(CONFIG_HAVE_CLK)
+		if (IS_ERR(drv_data->clk)) {
+			rc = -ENODEV;
+			goto exit_unmap_regs;
+		}
+		tclk = clk_get_rate(drv_data->clk);
+		of_property_read_u32(pd->dev.of_node, "clock-frequency",
+				     &bus_freq);
+		if (!find_baud_factors(bus_freq, tclk,
+				       &drv_data->freq_n, &drv_data->freq_m)) {
+			rc = -EINVAL;
+			goto exit_unmap_regs;
+		}
+		drv_data->irq = irq_of_parse_and_map(pd->dev.of_node, 0);
+#else
+		/* Have OF but no CLK */
+		rc = -ENODEV;
+		goto exit_unmap_regs;
+#endif
+	}
+#endif
 	if (drv_data->irq < 0) {
 		rc = -ENXIO;
 		goto exit_unmap_regs;
 	}
+
 	drv_data->adapter.dev.parent = &pd->dev;
 	drv_data->adapter.algo = &mv64xxx_i2c_algo;
 	drv_data->adapter.owner = THIS_MODULE;
 	drv_data->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
-	drv_data->adapter.timeout = msecs_to_jiffies(pdata->timeout);
+	if (pd->dev.of_node)
+		drv_data->adapter.timeout = msecs_to_jiffies(
+			of_property_read_u32(pd->dev.of_node, "timeout-ms",
+					     &drv_data->freq_n));
+	else
+		drv_data->adapter.timeout = msecs_to_jiffies(pdata->timeout);
 	drv_data->adapter.nr = pd->id;
+	drv_data->adapter.dev.of_node = pd->dev.of_node;
 	platform_set_drvdata(pd, drv_data);
 	i2c_set_adapdata(&drv_data->adapter, drv_data);
 
@@ -577,6 +658,8 @@  mv64xxx_i2c_probe(struct platform_device *pd)
 		goto exit_free_irq;
 	}
 
+	of_i2c_register_devices(&drv_data->adapter);
+
 	return 0;
 
 	exit_free_irq:
@@ -597,17 +680,31 @@  mv64xxx_i2c_remove(struct platform_device *dev)
 	rc = i2c_del_adapter(&drv_data->adapter);
 	free_irq(drv_data->irq, drv_data);
 	mv64xxx_i2c_unmap_regs(drv_data);
+#if defined(CONFIG_HAVE_CLK)
+	/* Not all platforms have a clk */
+	if (!IS_ERR(drv_data->clk)) {
+		clk_disable(drv_data->clk);
+		clk_unprepare(drv_data->clk);
+	}
+#endif
 	kfree(drv_data);
 
 	return rc;
 }
 
+static const struct of_device_id mv64xxx_i2c_of_match_table[] __devinitdata = {
+	{ .compatible = "marvell,mv64xxx-i2c", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, mv64xxx_i2c_of_match_table);
+
 static struct platform_driver mv64xxx_i2c_driver = {
 	.probe	= mv64xxx_i2c_probe,
 	.remove	= __devexit_p(mv64xxx_i2c_remove),
 	.driver	= {
 		.owner	= THIS_MODULE,
 		.name	= MV64XXX_I2C_CTLR_NAME,
+		.of_match_table = of_match_ptr(mv64xxx_i2c_of_match_table),
 	},
 };