leds: provide helper to register "leds-gpio" devices

This function makes a deep copy of the platform data to allow it to live
in init memory.  For a kernel that supports several machines and so
includes the definition for several leds-gpio devices this saves quite
some memory because all but one definition can be free'd after boot.

As the function is used by arch code it must be builtin and so cannot go
into leds-gpio.c.

[akpm@linux-foundation.org: s/CONFIG_LED_REGISTER_GPIO/CONFIG_LEDS_REGISTER_GPIO/]
Signed-off-by: Uwe Kleine-König  <u.kleine-koenig@pengutronix.de>
Cc: Russell King <rmk@arm.linux.org.uk>
Acked-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Tested-by: H Hartley Sweeten <hartleys@visionengravers.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/Makefile b/drivers/Makefile
index 145aeadb6c034d4e058ea782c64d90775879c20c..bceb60c85c016bcfc2ce51aff6c88666e867f208 100644 (file)
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -94,7 +94,7 @@ obj-$(CONFIG_CPU_IDLE)                += cpuidle/
 obj-$(CONFIG_DMA_ENGINE)       += dma/
 obj-$(CONFIG_MMC)              += mmc/
 obj-$(CONFIG_MEMSTICK)         += memstick/
-obj-$(CONFIG_NEW_LEDS)         += leds/
+obj-y                          += leds/
 obj-$(CONFIG_INFINIBAND)       += infiniband/
 obj-$(CONFIG_SGI_SN)           += sn/
 obj-y                          += firmware/

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index a4a77734ab6e59fbf874944c5ad37d6b7f820ea3..1d027b475b22563c7d0c5eea64103b4e0b48d307 100644 (file)
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -14,6 +14,13 @@ config LEDS_CLASS
          This option enables the led sysfs class in /sys/class/leds.  You'll
          need this to do anything useful with LEDs.  If unsure, say N.
 
+config LEDS_GPIO_REGISTER
+       bool
+       help
+         This option provides the function gpio_led_register_device.
+         As this function is used by arch code it must not be compiled as a
+         module.
+
 if NEW_LEDS
 
 comment "LED drivers"

diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 0b6ad375bfdb0ef47ab8dd7609e2a3f72c1217b6..bccb96c9bb45b467cbf14d0bf0c4e338796f8dce 100644 (file)
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -21,6 +21,7 @@ obj-$(CONFIG_LEDS_COBALT_QUBE)                += leds-cobalt-qube.o
 obj-$(CONFIG_LEDS_COBALT_RAQ)          += leds-cobalt-raq.o
 obj-$(CONFIG_LEDS_SUNFIRE)             += leds-sunfire.o
 obj-$(CONFIG_LEDS_PCA9532)             += leds-pca9532.o
+obj-$(CONFIG_LEDS_GPIO_REGISTER)       += leds-gpio-register.o
 obj-$(CONFIG_LEDS_GPIO)                        += leds-gpio.o
 obj-$(CONFIG_LEDS_LP3944)              += leds-lp3944.o
 obj-$(CONFIG_LEDS_LP5521)              += leds-lp5521.o

diff --git a/drivers/leds/leds-gpio-register.c b/drivers/leds/leds-gpio-register.c
new file mode 100644 (file)
index 0000000..1c4ed55
--- /dev/null
+++ b/drivers/leds/leds-gpio-register.c
@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2011 Pengutronix
+ * Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License version 2 as published by the
+ * Free Software Foundation.
+ */
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/leds.h>
+
+/**
+ * gpio_led_register_device - register a gpio-led device
+ * @pdata: the platform data used for the new device
+ *
+ * Makes a copy of pdata and pdata->leds and registers a new leds-gpio device
+ * with the result. This allows to have pdata and pdata-leds in .init.rodata
+ * and so saves some bytes compared to a static struct platform_device with
+ * static platform data.
+ *
+ * Returns the registered device or an error pointer.
+ */
+struct platform_device *__init gpio_led_register_device(
+               int id, const struct gpio_led_platform_data *pdata)
+{
+       struct platform_device *ret;
+       struct gpio_led_platform_data _pdata = *pdata;
+
+       _pdata.leds = kmemdup(pdata->leds,
+                       pdata->num_leds * sizeof(*pdata->leds), GFP_KERNEL);
+       if (!_pdata.leds)
+               return ERR_PTR(-ENOMEM);
+
+       ret = platform_device_register_resndata(NULL, "leds-gpio", id,
+                       NULL, 0, &_pdata, sizeof(_pdata));
+       if (IS_ERR(ret))
+               kfree(_pdata.leds);
+
+       return ret;
+}

diff --git a/include/linux/leds.h b/include/linux/leds.h
index 61e0340a4b770c3675787130afdc8174eb902262..5884def15a24872a2b4be5ef9abe815fad233388 100644 (file)
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -207,5 +207,7 @@ struct gpio_led_platform_data {
                                        unsigned long *delay_off);
 };
 
+struct platform_device *gpio_led_register_device(
+               int id, const struct gpio_led_platform_data *pdata);
 
 #endif         /* __LINUX_LEDS_H_INCLUDED */