[RFC PATCH 5/7] ARM: davinci: i2c: add OF support
Heiko Schocher
hs at denx.de
Tue Jan 31 18:14:28 EST 2012
Hello Grant,
Grant Likely wrote:
> On Mon, Jan 23, 2012 at 09:56:05AM +0100, Heiko Schocher wrote:
>> add of support for the davinci i2c driver.
>>
>> Signed-off-by: Heiko Schocher <hs at denx.de>
>> Cc: davinci-linux-open-source at linux.davincidsp.com
>> Cc: linux-arm-kernel at lists.infradead.org
>> Cc: devicetree-discuss at lists.ozlabs.org
>> Cc: linux-i2c at vger.kernel.org
>> Cc: Ben Dooks <ben-linux at fluff.org>
>> Cc: Wolfram Sang <w.sang at pengutronix.de>
>> Cc: Grant Likely <grant.likely at secretlab.ca>
>> Cc: Sekhar Nori <nsekhar at ti.com>
>> Cc: Wolfgang Denk <wd at denx.de>
>
> Hi Heiko,
>
> comments below.
Thanks!
>> ---
>> .../devicetree/bindings/arm/davinci/i2c.txt | 39 ++++++++++++++++++
>> drivers/i2c/busses/i2c-davinci.c | 43 ++++++++++++++++++++
>> 2 files changed, 82 insertions(+), 0 deletions(-)
>> create mode 100644 Documentation/devicetree/bindings/arm/davinci/i2c.txt
>>
>> diff --git a/Documentation/devicetree/bindings/arm/davinci/i2c.txt b/Documentation/devicetree/bindings/arm/davinci/i2c.txt
>> new file mode 100644
>> index 0000000..94ec670
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/arm/davinci/i2c.txt
>> @@ -0,0 +1,39 @@
>> +* Texas Instruments Davinci I2C
>> +
>> +This file provides information, what the device node for the
>> +davinci i2c interface contain.
>> +
>> +Required properties:
>> +- compatible: "ti,davinci-i2c";
>> +- reg : Offset and length of the register set for the device
>> +- id: id of the controller
>
> Don't use an 'id' property. i2c bus numbers should be dynamically
> assigned when using the device tree.
Yep, removed!
>> +
>> +Recommended properties :
>> +- interrupts : <a b> where a is the interrupt number and b is a
>> + field that represents an encoding of the sense and level
>> + information for the interrupt.
>
> This is inaccurate. It is entirely defined by the interrupt
> controller. All you need to say here is that this is a standard
> interrupts property.
fixed.
>> +- interrupt-parent : the phandle for the interrupt controller that
>> + services interrupts for this device.
>
> Don't even mention this one. It can often be inherited from a parent
> node.
deleted.
[...]
>> diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
>> index a76d85f..6f59fae 100644
>> --- a/drivers/i2c/busses/i2c-davinci.c
>> +++ b/drivers/i2c/busses/i2c-davinci.c
>> @@ -38,9 +38,12 @@
>> #include <linux/slab.h>
>> #include <linux/cpufreq.h>
>> #include <linux/gpio.h>
>> +#include <linux/of_i2c.h>
>> +#include <linux/of_device.h>
>>
>> #include <mach/hardware.h>
>> #include <mach/i2c.h>
>> +#include <mach/mux.h>
>>
>> /* ----- global defines ----------------------------------------------- */
>>
>> @@ -635,6 +638,16 @@ static struct i2c_algorithm i2c_davinci_algo = {
>> .functionality = i2c_davinci_func,
>> };
>>
>> +#if defined(CONFIG_OF)
>> +static const struct of_device_id davinci_i2c_of_match[] = {
>> + {.compatible = "ti,davinci-i2c", },
>> + {},
>> +}
>> +MODULE_DEVICE_TABLE(of, davinci_i2c_of_match);
>> +#else
>> +#define davinci_i2c_of_match NULL
>> +#endif
>
> The #else clause can be dropped if you use the of_match_ptr() macro
> when referencing it.
removed.
>> +
>> static int davinci_i2c_probe(struct platform_device *pdev)
>> {
>> struct davinci_i2c_dev *dev;
>> @@ -676,7 +689,34 @@ static int davinci_i2c_probe(struct platform_device *pdev)
>> dev->irq = irq->start;
>> platform_set_drvdata(pdev, dev);
>>
>> + if ((dev->dev->platform_data == NULL) &&
>> + (pdev->dev.of_node)) {
>> + struct device_node *pinmux_np;
>> + struct davinci_i2c_platform_data *pdata;
>> + u32 prop;
>> +
>> + dev->dev->platform_data = &davinci_i2c_platform_data_default;
>
> Don't do this. What if a davinci part shows up with two i2c busses?
> Use devm_kzalloc() instead.
Fixed.
>> + pdata = &davinci_i2c_platform_data_default;
>> + if (!of_property_read_u32(pdev->dev.of_node, "clock-frequency",
>> + &prop))
>> + pdata->bus_freq = prop / 1000;
>> + if (!of_property_read_u32(pdev->dev.of_node, "bus-delay",
>> + &prop))
>> + pdata->bus_delay = prop;
>> + if (!of_property_read_u32(pdev->dev.of_node, "id",
>> + &prop)) {
>> + pdev->id = prop;
>> + pdev->dev.init_name = kzalloc(20, GFP_KERNEL);
>> + sprintf((char *)pdev->dev.init_name,
>> + "i2c_davinci.%d", pdev->id);
>
> Blech! Drop this. Leave the core code to set the device name.
completely removed.
>> dev->clk = clk_get(&pdev->dev, NULL);
>> +
>> if (IS_ERR(dev->clk)) {
>
> Nit: unrelated whitespace change
Ups, good catch, fixed.
[...]
bye,
Heiko
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