Subject: [PATCH 06/13] mfd: twl-core: Add initial DT support for twl4030/twl6030

From: [email-masked] (Cousson, Benoit)
Date: Wed, 28 Sep 2011 10:52:29 +0200

On 9/27/2011 7:42 AM, Nayak, Rajendra wrote:
> On Monday 26 September 2011 10:20 PM, Benoit Cousson wrote:
>> Add initial device-tree support for twl familly chips.
>
> s/familly/family

Oops.

>> The current version is missing the regulator entries due
>> to the lack of DT regulator bindings for the moment.
>> Only the simple sub-modules that do not depend on
>> platform_data information can be initialized properly.
>>
>> Add documentation for the Texas Instruments TWL Integrated Chip.
>>
>> Signed-off-by: Benoit Cousson<[email-masked]>
>> Cc: Balaji T K<[email-masked]>
>> Cc: Graeme Gregory<[email-masked]>
>> Cc: Samuel Ortiz<[email-masked]>
>> ---
>>    .../devicetree/bindings/mfd/twl-familly.txt        |   47 +++++++++++++++++
>>    drivers/mfd/twl-core.c                             |   53 ++++++++++++++++++--
>>    2 files changed, 96 insertions(+), 4 deletions(-)
>>    create mode 100644 Documentation/devicetree/bindings/mfd/twl-familly.txt
>
> s/familly.txt/family.txt

At least I am consistent in my typos ;-)

>> diff --git a/Documentation/devicetree/bindings/mfd/twl-familly.txt b/Documentation/devicetree/bindings/mfd/twl-familly.txt
>> new file mode 100644
>> index 0000000..ff4cacd
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/mfd/twl-familly.txt
>> @@ -0,0 +1,47 @@
>> +Texas Instruments TWL family
>> +
>> +The TWLs are Integrated Power Management Chips.
>> +Some version might contain much more analog function like
>> +USB transceiver or Audio amplifier.
>> +These chips are connected to an i2c bus.
>> +
>> +
>> +Required properties:
>> +- compatible : Must be "ti,twl4030";
>> +  For Integrated power-management/audio CODEC device used in OMAP3
>> +  based boards
>> +- compatible : Must be "ti,twl6030";
>> +  For Integrated power-management used in OMAP4 based boards
>> +- interrupts : This i2c device has an IRQ line connected to the main SoC
>> +- interrupt-controller : Since the twl support several interrupts internally,
>> +  it is considered as an interrupt controller cascaded to the SoC one.
>> +- #interrupt-cells =<1>;
>> +- interrupt-parent : The parent interrupt controller.
>> +
>> +Optional node:
>> +- Child nodes contain in the twl. The twl family is made of severals variants
>> +  that support a different number of features.
>> +  The children nodes will thus depend of the capabilty of the variant.
>> +
>> +
>> +Example:
>> +/*
>> + * Integrated Power Management Chip
>> + * http://www.ti.com/lit/ds/symlink/twl6030.pdf
>> + */
>> +twl at 48 {
>> +    compatible = "ti,twl6030";
>> +    reg =<0x48>;
>
> What does the 'reg' property signify here for twl?

The i2c slave address.

>> +    interrupts =<39>; /* IRQ_SYS_1N cascaded to gic */
>> +    interrupt-controller;
>> +    #interrupt-cells =<1>;
>> +    interrupt-parent =<&gic>;
>> +    #address-cells =<1>;
>> +    #size-cells =<0>;
>> +
>> +    twl_rtc {
>> +        compatible = "ti,twl_rtc";
>> +        interrupts =<11>;
>> +        reg =<0>;
>
> Does the 'reg' property need to be faked for
> every twl child node, even if it does not have
> any?

No, it was even removed from the DTS. But I forgot to update the 
documentation:-(

>> +    };
>> +};
>> diff --git a/drivers/mfd/twl-core.c b/drivers/mfd/twl-core.c
>> index 01ecfee..3ef0b43 100644
>> --- a/drivers/mfd/twl-core.c
>> +++ b/drivers/mfd/twl-core.c
>> @@ -33,6 +33,10 @@
>>    #include<linux/platform_device.h>
>>    #include<linux/clk.h>
>>    #include<linux/err.h>
>> +#include<linux/slab.h>
>> +#include<linux/of_irq.h>
>> +#include<linux/of_platform.h>
>> +#include<linux/irqdomain.h>
>>
>>    #include<linux/regulator/machine.h>
>>
>> @@ -1182,22 +1186,53 @@ twl_probe(struct i2c_client *client, const struct i2c_device_id *id)
>>    	int				status;
>>    	unsigned			i;
>>    	struct twl4030_platform_data	*pdata = client->dev.platform_data;
>> +	struct device_node		*node = client->dev.of_node;
>>    	u8 temp;
>>    	int ret = 0;
>>
>> +	if (node&&   !pdata) {
>> +		/*
>> +		 * XXX: Temporary fake pdata until the information
>> +		 * is correctly retrieved by every TWL modules from DT.
>> +		 */
>> +		pdata = kzalloc(sizeof(struct twl4030_platform_data),
>> +				GFP_KERNEL);
>
> devm_kzalloc instead?

Good point.

>> +		if (!pdata) {
>> +			status = -ENOMEM;
>> +			goto exit;
>> +		}
>> +
>> +		/*
>> +		 * XXX: For the moment the IRQs for TWL seems to be encoded in
>> +		 * the global OMAP space. That should be cleaned to allow
>> +		 * dynamically adding a new IRQ controller.
>> +		 */
>> +		if ((id->driver_data)&   TWL6030_CLASS) {
>> +			pdata->irq_base = TWL6030_IRQ_BASE;
>> +			pdata->irq_end = pdata->irq_base + TWL6030_BASE_NR_IRQS;
>> +		} else {
>> +			pdata->irq_base = TWL4030_IRQ_BASE;
>> +			pdata->irq_end = pdata->irq_base + TWL4030_BASE_NR_IRQS;
>> +		}
>> +		irq_domain_add_simple(node, pdata->irq_base);
>> +	}
>> +
>>    	if (!pdata) {
>>    		dev_dbg(&client->dev, "no platform data?\n");
>> -		return -EINVAL;
>> +		status = -EINVAL;
>> +		goto fail_free;
>>    	}
>>
>>    	if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C) == 0) {
>>    		dev_dbg(&client->dev, "can't talk I2C?\n");
>> -		return -EIO;
>> +		status = -EIO;
>> +		goto fail_free;
>>    	}
>>
>>    	if (inuse) {
>>    		dev_dbg(&client->dev, "driver is already in use\n");
>> -		return -EBUSY;
>> +		status = -EBUSY;
>> +		goto fail_free;
>>    	}
>>
>>    	for (i = 0; i<   TWL_NUM_SLAVES; i++) {
>> @@ -1269,10 +1304,20 @@ twl_probe(struct i2c_client *client, const struct i2c_device_id *id)
>>    		twl_i2c_write_u8(TWL4030_MODULE_INTBR, temp, REG_GPPUPDCTR1);
>>    	}
>>
>> -	status = add_children(pdata, id->driver_data);
>> +#ifdef CONFIG_OF_DEVICE
>
> is the #ifdef really needed?

Yes, because the of_platform_populate does not have a stub in case of 
none DT build... But I agree, it is ugly and the of_platform.h should 
maybe be fixed instead.
I was too lazy to fix it :-)

Thanks,
Benoit