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Message-Id: <6C87C279-4ED7-4E37-88FA-87C61437975F@antoniou-consulting.com>
Date: Wed, 29 Oct 2014 10:19:33 +0200
From: Pantelis Antoniou <panto@...oniou-consulting.com>
To: Alexander Sverdlin <alexander.sverdlin@....com>
Cc: Grant Likely <grant.likely@...retlab.ca>,
Rob Herring <robherring2@...il.com>,
Stephen Warren <swarren@...dotorg.org>,
Matt Porter <matt.porter@...aro.org>,
Koen Kooi <koen@...inion.thruhere.net>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Alison Chaiken <Alison_Chaiken@...tor.com>,
Dinh Nguyen <dinh.linux@...il.com>,
Jan Lubbe <jluebbe@...net.de>, Michael Stickel <ms@...able.de>,
Guenter Roeck <linux@...ck-us.net>,
Dirk Behme <dirk.behme@...il.com>,
Alan Tull <delicious.quinoa@...il.com>,
Sascha Hauer <s.hauer@...gutronix.de>,
Michael Bohan <mbohan@...eaurora.org>,
Ionut Nicu <ioan.nicu.ext@....com>,
Michal Simek <monstr@...str.eu>,
Matt Ranostay <mranostay@...il.com>,
Joel Becker <jlbec@...lplan.org>, devicetree@...r.kernel.org,
Wolfram Sang <wsa@...-dreams.de>, linux-i2c@...r.kernel.org,
Mark Brown <broonie@...nel.org>, linux-spi@...r.kernel.org,
linux-kernel <linux-kernel@...r.kernel.org>,
Pete Popov <pete.popov@...sulko.com>,
Dan Malek <dan.malek@...sulko.com>,
Georgi Vlaev <georgi.vlaev@...sulko.com>,
"Wiebe, Wladislav (NSN - DE/Ulm)" <wladislav.wiebe@....com>
Subject: Re: [PATCH v8 7/8] of: spi: Export single device registration method and accessors
Hi Alexander,
> On Oct 29, 2014, at 09:44 , Alexander Sverdlin <alexander.sverdlin@....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@...sulko.com>
>> ---
>> 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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