Re: [PATCH v8 7/8] of: spi: Export single device registration method and accessors

[Pantelis Antoniou <panto-wVdstyuyKrO8r51toPun2/C9HSW9iNxf@public.gmane.org>]

Hi Alexander,

> On Oct 29, 2014, at 09:44 , Alexander Sverdlin <alexander.sverdlin@nsn.com> wrote:
> 
> Hello Pantelis,
> 
> I've pointed to this already, but anyway:
> 
> On 28/10/14 21:36, ext Pantelis Antoniou wrote:
>> Dynamically inserting spi device nodes requires the use of a single
>> device registration method. Rework and export it.
>> 
>> Methods to lookup a device/master using a device node are added
>> as well, of_find_spi_master_by_node() & of_find_spi_device_by_node().
>> 
>> Signed-off-by: Pantelis Antoniou <pantelis.antoniou-OWPKS81ov/FWk0Htik3J/w@public.gmane.org>
>> ---
>> drivers/spi/spi.c | 256 +++++++++++++++++++++++++++++++++---------------------
>> 1 file changed, 158 insertions(+), 98 deletions(-)
>> 
>> diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
>> index ebcb33d..f81d799 100644
>> --- a/drivers/spi/spi.c
>> +++ b/drivers/spi/spi.c
>> @@ -1220,6 +1220,123 @@ err_init_queue:
>> /*-------------------------------------------------------------------------*/
>> 
>> #if defined(CONFIG_OF)
>> +
>> +static struct spi_device *
>> +of_register_spi_device(struct spi_master *master, struct device_node *node)
> 
> During the test Wladislav has found that node is actually not used,
> 

Ugh.

>> +{
>> +	struct spi_device *spi;
>> +	struct device_node *nc;
> 
> but non-initialized nc is used further in the code.
> Should not nc be a parameter of the function instead of a local variable?
> 

Yes, my mistake. Updated patch follows.

>> +	int rc;
>> +	u32 value;
>> +
>> +	/* Alloc an spi_device */
>> +	spi = spi_alloc_device(master);
>> +	if (!spi) {
>> +		dev_err(&master->dev, "spi_device alloc error for %s\n",
>> +			nc->full_name);
>> +		rc = -ENOMEM;
>> +		goto err_out;
>> +	}
>> +
>> +	/* Select device driver */
>> +	rc = of_modalias_node(nc, spi->modalias,
>> +				sizeof(spi->modalias));
>> +	if (rc < 0) {
>> +		dev_err(&master->dev, "cannot find modalias for %s\n",
>> +			nc->full_name);
>> +		goto err_out;
>> +	}
>> +
>> +	/* Device address */
>> +	rc = of_property_read_u32(nc, "reg", &value);
>> +	if (rc) {
>> +		dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n",
>> +			nc->full_name, rc);
>> +		goto err_out;
>> +	}
>> +	spi->chip_select = value;
>> +
>> +	/* Mode (clock phase/polarity/etc.) */
>> +	if (of_find_property(nc, "spi-cpha", NULL))
>> +		spi->mode |= SPI_CPHA;
>> +	if (of_find_property(nc, "spi-cpol", NULL))
>> +		spi->mode |= SPI_CPOL;
>> +	if (of_find_property(nc, "spi-cs-high", NULL))
>> +		spi->mode |= SPI_CS_HIGH;
>> +	if (of_find_property(nc, "spi-3wire", NULL))
>> +		spi->mode |= SPI_3WIRE;
>> +	if (of_find_property(nc, "spi-lsb-first", NULL))
>> +		spi->mode |= SPI_LSB_FIRST;
>> +
>> +	/* Device DUAL/QUAD mode */
>> +	if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
>> +		switch (value) {
>> +		case 1:
>> +			break;
>> +		case 2:
>> +			spi->mode |= SPI_TX_DUAL;
>> +			break;
>> +		case 4:
>> +			spi->mode |= SPI_TX_QUAD;
>> +			break;
>> +		default:
>> +			dev_warn(&master->dev,
>> +				"spi-tx-bus-width %d not supported\n",
>> +				value);
>> +			break;
>> +		}
>> +	}
>> +
>> +	if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
>> +		switch (value) {
>> +		case 1:
>> +			break;
>> +		case 2:
>> +			spi->mode |= SPI_RX_DUAL;
>> +			break;
>> +		case 4:
>> +			spi->mode |= SPI_RX_QUAD;
>> +			break;
>> +		default:
>> +			dev_warn(&master->dev,
>> +				"spi-rx-bus-width %d not supported\n",
>> +				value);
>> +			break;
>> +		}
>> +	}
>> +
>> +	/* Device speed */
>> +	rc = of_property_read_u32(nc, "spi-max-frequency", &value);
>> +	if (rc) {
>> +		dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n",
>> +			nc->full_name, rc);
>> +		goto err_out;
>> +	}
>> +	spi->max_speed_hz = value;
>> +
>> +	/* IRQ */
>> +	spi->irq = irq_of_parse_and_map(nc, 0);
>> +
>> +	/* Store a pointer to the node in the device structure */
>> +	of_node_get(nc);
>> +	spi->dev.of_node = nc;
>> +
>> +	/* Register the new device */
>> +	request_module("%s%s", SPI_MODULE_PREFIX, spi->modalias);
>> +	rc = spi_add_device(spi);
>> +	if (rc) {
>> +		dev_err(&master->dev, "spi_device register error %s\n",
>> +			nc->full_name);
>> +		goto err_out;
>> +	}
>> +
>> +	return spi;
>> +
>> +err_out:
>> +	spi_dev_put(spi);
>> +	return ERR_PTR(rc);
>> +}
>> +
>> /**
>>  * of_register_spi_devices() - Register child devices onto the SPI bus
>>  * @master:	Pointer to spi_master device
>> @@ -1229,120 +1346,63 @@ err_init_queue:
>>  */
>> static void of_register_spi_devices(struct spi_master *master)
>> {
>> -	struct spi_device *spi;
>> 	struct device_node *nc;
>> -	int rc;
>> -	u32 value;
>> +	struct spi_device *spi;
>> 
>> 	if (!master->dev.of_node)
>> 		return;
>> 
>> 	for_each_available_child_of_node(master->dev.of_node, nc) {
>> -		/* Alloc an spi_device */
>> -		spi = spi_alloc_device(master);
>> -		if (!spi) {
>> -			dev_err(&master->dev, "spi_device alloc error for %s\n",
>> +		spi = of_register_spi_device(master, nc);
>> +		if (IS_ERR(spi))
>> +			dev_warn(&master->dev, "Failed to create SPI device for %s\n",
>> 				nc->full_name);
>> -			spi_dev_put(spi);
>> -			continue;
>> -		}
>> +	}
>> +}
>> 
>> -		/* Select device driver */
>> -		if (of_modalias_node(nc, spi->modalias,
>> -				     sizeof(spi->modalias)) < 0) {
>> -			dev_err(&master->dev, "cannot find modalias for %s\n",
>> -				nc->full_name);
>> -			spi_dev_put(spi);
>> -			continue;
>> -		}
>> +static int of_dev_node_match(struct device *dev, void *data)
>> +{
>> +	return dev->of_node == data;
>> +}
>> 
>> -		/* Device address */
>> -		rc = of_property_read_u32(nc, "reg", &value);
>> -		if (rc) {
>> -			dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n",
>> -				nc->full_name, rc);
>> -			spi_dev_put(spi);
>> -			continue;
>> -		}
>> -		spi->chip_select = value;
>> -
>> -		/* Mode (clock phase/polarity/etc.) */
>> -		if (of_find_property(nc, "spi-cpha", NULL))
>> -			spi->mode |= SPI_CPHA;
>> -		if (of_find_property(nc, "spi-cpol", NULL))
>> -			spi->mode |= SPI_CPOL;
>> -		if (of_find_property(nc, "spi-cs-high", NULL))
>> -			spi->mode |= SPI_CS_HIGH;
>> -		if (of_find_property(nc, "spi-3wire", NULL))
>> -			spi->mode |= SPI_3WIRE;
>> -		if (of_find_property(nc, "spi-lsb-first", NULL))
>> -			spi->mode |= SPI_LSB_FIRST;
>> -
>> -		/* Device DUAL/QUAD mode */
>> -		if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
>> -			switch (value) {
>> -			case 1:
>> -				break;
>> -			case 2:
>> -				spi->mode |= SPI_TX_DUAL;
>> -				break;
>> -			case 4:
>> -				spi->mode |= SPI_TX_QUAD;
>> -				break;
>> -			default:
>> -				dev_warn(&master->dev,
>> -					 "spi-tx-bus-width %d not supported\n",
>> -					 value);
>> -				break;
>> -			}
>> -		}
>> +/* bah; the match functions differ just by const-ness */
>> +static int of_dev_node_match_const(struct device *dev, const void *data)
>> +{
>> +	return dev->of_node == data;
>> +}
>> 
>> -		if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
>> -			switch (value) {
>> -			case 1:
>> -				break;
>> -			case 2:
>> -				spi->mode |= SPI_RX_DUAL;
>> -				break;
>> -			case 4:
>> -				spi->mode |= SPI_RX_QUAD;
>> -				break;
>> -			default:
>> -				dev_warn(&master->dev,
>> -					 "spi-rx-bus-width %d not supported\n",
>> -					 value);
>> -				break;
>> -			}
>> -		}
>> +/* must call put_device() when done with returned spi_device device */
>> +struct spi_device *of_find_spi_device_by_node(struct device_node *node)
>> +{
>> +	struct device *dev;
>> 
>> -		/* Device speed */
>> -		rc = of_property_read_u32(nc, "spi-max-frequency", &value);
>> -		if (rc) {
>> -			dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n",
>> -				nc->full_name, rc);
>> -			spi_dev_put(spi);
>> -			continue;
>> -		}
>> -		spi->max_speed_hz = value;
>> +	dev = bus_find_device(&spi_bus_type, NULL, node,
>> +					 of_dev_node_match);
>> +	if (!dev)
>> +		return NULL;
>> 
>> -		/* IRQ */
>> -		spi->irq = irq_of_parse_and_map(nc, 0);
>> +	return to_spi_device(dev);
>> +}
>> +EXPORT_SYMBOL(of_find_spi_device_by_node);
>> 
>> -		/* Store a pointer to the node in the device structure */
>> -		of_node_get(nc);
>> -		spi->dev.of_node = nc;
>> +/* forward decl */
>> +static struct class spi_master_class;
>> 
>> -		/* Register the new device */
>> -		request_module("%s%s", SPI_MODULE_PREFIX, spi->modalias);
>> -		rc = spi_add_device(spi);
>> -		if (rc) {
>> -			dev_err(&master->dev, "spi_device register error %s\n",
>> -				nc->full_name);
>> -			spi_dev_put(spi);
>> -		}
>> +/* the spi masters are not using spi_bus, so we find it with another way */
>> +struct spi_master *of_find_spi_master_by_node(struct device_node *node)
>> +{
>> +	struct device *dev;
>> 
>> -	}
>> +	dev = class_find_device(&spi_master_class, NULL, node,
>> +				of_dev_node_match_const);
>> +	if (!dev)
>> +		return NULL;
>> +
>> +	/* reference got in class_find_device */
>> +	return container_of(dev, struct spi_master, dev);
>> }
>> +EXPORT_SYMBOL(of_find_spi_master_by_node);
>> +
>> #else
>> static void of_register_spi_devices(struct spi_master *master) { }
>> #endif
>> 
> 
> -- 
> Best regards,
> Alexander Sverdlin.

Regards

— Pantelis

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