Re: [PATCH v4 3/3] p54: convert to sysdata API

["Luis R. Rodriguez" <mcgrof@kernel.org>]

On Thu, Jan 19, 2017 at 05:27:51PM +0100, Luis R. Rodriguez wrote:
> On Thu, Jan 19, 2017 at 12:38:57PM +0100, Greg KH wrote:
> > On Thu, Jan 12, 2017 at 07:02:44AM -0800, Luis R. Rodriguez wrote:
> > > ---
> > >  drivers/net/wireless/intersil/p54/eeprom.c |  2 +-
> > >  drivers/net/wireless/intersil/p54/fwio.c   |  5 +-
> > >  drivers/net/wireless/intersil/p54/led.c    |  2 +-
> > >  drivers/net/wireless/intersil/p54/main.c   |  2 +-
> > >  drivers/net/wireless/intersil/p54/p54.h    |  3 +-
> > >  drivers/net/wireless/intersil/p54/p54pci.c | 26 ++++++----
> > >  drivers/net/wireless/intersil/p54/p54pci.h |  4 +-
> > >  drivers/net/wireless/intersil/p54/p54spi.c | 80 +++++++++++++++++++-----------
> > >  drivers/net/wireless/intersil/p54/p54spi.h |  2 +-
> > >  drivers/net/wireless/intersil/p54/p54usb.c | 18 +++----
> > >  drivers/net/wireless/intersil/p54/p54usb.h |  4 +-
> > >  drivers/net/wireless/intersil/p54/txrx.c   |  2 +-
> > >  12 files changed, 89 insertions(+), 61 deletions(-)
> > 
> > why does the "new" api require more lines?
> 
> This is a bare bones flexible API with only a few new tiny features to start
> with, one of them was to enable the API do the freeing of the driver data for
> you. In the kernel we have devres to help with this but devres only helps if
> you would use the API call on probe. We want to support the ability to let the
> API free the driver data for you even if your call is outside of probe, for this
> to work we need a callback. For async calls this is rather trivial given we
> already have a callback, for sync calls this means a new routine is needed.
> Freeing the data for you is an option, but I decided to keep the callback
> requirement even if you didn't want the free'ing to be done for you. The
> addition of a callback is what accounts for the slight increase on this driver.
> 
> I could try avoiding the callback if no freeing is needed.

OK I've added a respective helper call which would map 1-1 with the
old sync mechanism to enable a 1-1 change, this will be called
driver_data_request_simple(), but let me know if there is a preference
for something else.

With this the only visible delta now is from taking advantage of new
features. In p54's case this would re-organize the mess in
drivers/net/wireless/intersil/p54/p54spi.c, the diff stat is a bit
larger for that file just because of this but I think in this case
its very much worth the small additions. In this case two routines are
added for handling the work through callbacks on a sync call.

 1 file changed, 38 insertions(+), 30 deletions(-)

diff --git a/drivers/net/wireless/intersil/p54/p54spi.c b/drivers/net/wireless/intersil/p54/p54spi.c
index 7ab2f43ab425..6183a8bfa149 100644
--- a/drivers/net/wireless/intersil/p54/p54spi.c
+++ b/drivers/net/wireless/intersil/p54/p54spi.c
@@ -23,7 +23,7 @@
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/interrupt.h>
-#include <linux/firmware.h>
+#include <linux/driver_data.h>
 #include <linux/delay.h>
 #include <linux/irq.h>
 #include <linux/spi/spi.h>
@@ -168,47 +168,55 @@ static int p54spi_request_firmware(struct ieee80211_hw *dev)
 	int ret;
 
 	/* FIXME: should driver use it's own struct device? */
-	ret = request_firmware(&priv->firmware, "3826.arm", &priv->spi->dev);
-
-	if (ret < 0) {
-		dev_err(&priv->spi->dev, "request_firmware() failed: %d", ret);
+	ret = driver_data_request_simple("3826.arm", &priv->spi->dev,
+					 &priv->firmware);
+	if (ret < 0)
 		return ret;
-	}
 
 	ret = p54_parse_firmware(dev, priv->firmware);
 	if (ret) {
-		release_firmware(priv->firmware);
+		release_driver_data(priv->firmware);
 		return ret;
 	}
-
 	return 0;
 }
 
-static int p54spi_request_eeprom(struct ieee80211_hw *dev)
+#ifdef CONFIG_P54_SPI_DEFAULT_EEPROM
+static int p54spi_load_eeprom_default(void *context)
 {
-	struct p54s_priv *priv = dev->priv;
-	const struct firmware *eeprom;
-	int ret;
+	struct p54s_priv *priv = context;
+	struct ieee80211_hw *dev = priv->hw;
 
-	/* allow users to customize their eeprom.
-	 */
+	dev_info(&priv->spi->dev, "loading default eeprom...\n");
+	return p54_parse_eeprom(dev, (void *) p54spi_eeprom,
+				sizeof(p54spi_eeprom));
+}
+#endif
 
-	ret = request_firmware_direct(&eeprom, "3826.eeprom", &priv->spi->dev);
-	if (ret < 0) {
+static int p54spi_load_eeprom_cb(void *context,
+				 const struct driver_data *driver_data)
+{
+	struct p54s_priv *priv = context;
+	struct ieee80211_hw *dev = priv->hw;
+
+	dev_info(&priv->spi->dev, "loading user eeprom...\n");
+	return p54_parse_eeprom(dev, (void *) driver_data->data,
+				(int)driver_data->size);
+}
+static int p54spi_request_eeprom(struct ieee80211_hw *dev)
+{
+	struct p54s_priv *priv = dev->priv;
+	const struct driver_data_req_params req_params = {
+		DRIVER_DATA_DEFAULT_SYNC(p54spi_load_eeprom_cb, priv),
 #ifdef CONFIG_P54_SPI_DEFAULT_EEPROM
-		dev_info(&priv->spi->dev, "loading default eeprom...\n");
-		ret = p54_parse_eeprom(dev, (void *) p54spi_eeprom,
-				       sizeof(p54spi_eeprom));
-#else
-		dev_err(&priv->spi->dev, "Failed to request user eeprom\n");
-#endif /* CONFIG_P54_SPI_DEFAULT_EEPROM */
-	} else {
-		dev_info(&priv->spi->dev, "loading user eeprom...\n");
-		ret = p54_parse_eeprom(dev, (void *) eeprom->data,
-				       (int)eeprom->size);
-		release_firmware(eeprom);
-	}
-	return ret;
+		DRIVER_DATA_SYNC_OPT_CB(p54spi_load_eeprom_default, priv),
+#endif
+	};
+	/*
+	 * allow users to customize their eeprom.
+	 */
+	return driver_data_request("3826.eeprom", &req_params,
+				   &priv->spi->dev);
 }
 
 static int p54spi_upload_firmware(struct ieee80211_hw *dev)
@@ -692,7 +700,7 @@ static int p54spi_remove(struct spi_device *spi)
 
 	gpio_free(p54spi_gpio_power);
 	gpio_free(p54spi_gpio_irq);
-	release_firmware(priv->firmware);
+	release_driver_data(priv->firmware);
 
 	mutex_destroy(&priv->mutex);