summaryrefslogtreecommitdiff
path: root/drivers/leds/leds-syscon.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2014-10-08 17:37:16 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2014-10-08 17:37:16 -0400
commit8b45bc892e6842115fc87c2b2a3b86a20617606a (patch)
tree636c804eb29bb97070e7d2bc4d5ab9d1dad27cac /drivers/leds/leds-syscon.c
parenteb785bef684f2b7d03b530efc8e6f199e9777e2f (diff)
parentfa637bf0595ee1796d728a0d33b6b7fff12e1f3d (diff)
Merge tag 'drivers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC driver updates from Arnd Bergmann: "These are changes for drivers that are intimately tied to some SoC and for some reason could not get merged through the respective subsystem maintainer tree. Most of the new code is for the Keystone Navigator driver, which is new base support that is going to be needed for their hardware accelerated network driver and other units. Most of the commits are for moving old code around from at91 and omap for things that are done in device drivers nowadays. - at91: move reset, poweroff, memory and clocksource code into drivers directories - socfpga: add edac driver (through arm-soc, as requested by Boris) - omap: move omap-intc code to drivers/irqchip - sunxi: added an RTC driver for sun6i - omap: mailbox driver related changes - keystone: support for the "Navigator" component - versatile: new reboot, led and soc drivers" * tag 'drivers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (92 commits) bus: arm-ccn: Fix spurious warning message leds: add device tree bindings for register bit LEDs soc: add driver for the ARM RealView power: reset: driver for the Versatile syscon reboot leds: add a driver for syscon-based LEDs drivers/soc: ti: fix build break with modules MAINTAINERS: Add Keystone Multicore Navigator drivers entry soc: ti: add Keystone Navigator DMA support Documentation: dt: soc: add Keystone Navigator DMA bindings soc: ti: add Keystone Navigator QMSS driver Documentation: dt: soc: add Keystone Navigator QMSS bindings rtc: sunxi: Depend on platforms sun4i/sun7i that actually have the rtc rtc: sun6i: Add sun6i RTC driver irqchip: omap-intc: remove unnecessary comments irqchip: omap-intc: correct maximum number or MIR registers irqchip: omap-intc: enable TURBO idle mode irqchip: omap-intc: enable IP protection irqchip: omap-intc: remove unnecesary of_address_to_resource() call irqchip: omap-intc: comment style cleanup irqchip: omap-intc: minor improvement to omap_irq_pending() ...
Diffstat (limited to 'drivers/leds/leds-syscon.c')
-rw-r--r--drivers/leds/leds-syscon.c166
1 files changed, 166 insertions, 0 deletions
diff --git a/drivers/leds/leds-syscon.c b/drivers/leds/leds-syscon.c
new file mode 100644
index 000000000000..3afec79c43f4
--- /dev/null
+++ b/drivers/leds/leds-syscon.c
@@ -0,0 +1,166 @@
+/*
+ * Generic Syscon LEDs Driver
+ *
+ * Copyright (c) 2014, Linaro Limited
+ * Author: Linus Walleij <linus.walleij@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ * This driver provides system reboot functionality for APM X-Gene SoC.
+ * For system shutdown, this is board specify. If a board designer
+ * implements GPIO shutdown, use the gpio-poweroff.c driver.
+ */
+#include <linux/io.h>
+#include <linux/of_device.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/stat.h>
+#include <linux/slab.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/leds.h>
+
+/**
+ * struct syscon_led - state container for syscon based LEDs
+ * @cdev: LED class device for this LED
+ * @map: regmap to access the syscon device backing this LED
+ * @offset: the offset into the syscon regmap for the LED register
+ * @mask: the bit in the register corresponding to the LED
+ * @state: current state of the LED
+ */
+struct syscon_led {
+ struct led_classdev cdev;
+ struct regmap *map;
+ u32 offset;
+ u32 mask;
+ bool state;
+};
+
+static void syscon_led_set(struct led_classdev *led_cdev,
+ enum led_brightness value)
+{
+ struct syscon_led *sled =
+ container_of(led_cdev, struct syscon_led, cdev);
+ u32 val;
+ int ret;
+
+ if (value == LED_OFF) {
+ val = 0;
+ sled->state = false;
+ } else {
+ val = sled->mask;
+ sled->state = true;
+ }
+
+ ret = regmap_update_bits(sled->map, sled->offset, sled->mask, val);
+ if (ret < 0)
+ dev_err(sled->cdev.dev, "error updating LED status\n");
+}
+
+static const struct of_device_id syscon_match[] = {
+ { .compatible = "syscon", },
+ {},
+};
+
+static int __init syscon_leds_init(void)
+{
+ const struct of_device_id *devid;
+ struct device_node *np;
+ struct device_node *child;
+ struct regmap *map;
+ struct platform_device *pdev;
+ struct device *dev;
+ int ret;
+
+ np = of_find_matching_node_and_match(NULL, syscon_match,
+ &devid);
+ if (!np)
+ return -ENODEV;
+
+ map = syscon_node_to_regmap(np);
+ if (IS_ERR(map))
+ return PTR_ERR(map);
+
+ /*
+ * If the map is there, the device should be there, we allocate
+ * memory on the syscon device's behalf here.
+ */
+ pdev = of_find_device_by_node(np);
+ if (!pdev)
+ return -ENODEV;
+ dev = &pdev->dev;
+
+ for_each_available_child_of_node(np, child) {
+ struct syscon_led *sled;
+ const char *state;
+
+ /* Only check for register-bit-leds */
+ if (of_property_match_string(child, "compatible",
+ "register-bit-led") < 0)
+ continue;
+
+ sled = devm_kzalloc(dev, sizeof(*sled), GFP_KERNEL);
+ if (!sled)
+ return -ENOMEM;
+
+ sled->map = map;
+
+ if (of_property_read_u32(child, "offset", &sled->offset))
+ return -EINVAL;
+ if (of_property_read_u32(child, "mask", &sled->mask))
+ return -EINVAL;
+ sled->cdev.name =
+ of_get_property(child, "label", NULL) ? : child->name;
+ sled->cdev.default_trigger =
+ of_get_property(child, "linux,default-trigger", NULL);
+
+ state = of_get_property(child, "default-state", NULL);
+ if (state) {
+ if (!strcmp(state, "keep")) {
+ u32 val;
+
+ ret = regmap_read(map, sled->offset, &val);
+ if (ret < 0)
+ return ret;
+ sled->state = !!(val & sled->mask);
+ } else if (!strcmp(state, "on")) {
+ sled->state = true;
+ ret = regmap_update_bits(map, sled->offset,
+ sled->mask,
+ sled->mask);
+ if (ret < 0)
+ return ret;
+ } else {
+ sled->state = false;
+ ret = regmap_update_bits(map, sled->offset,
+ sled->mask, 0);
+ if (ret < 0)
+ return ret;
+ }
+
+ }
+ sled->cdev.brightness_set = syscon_led_set;
+
+ ret = led_classdev_register(dev, &sled->cdev);
+ if (ret < 0)
+ return ret;
+
+ dev_info(dev, "registered LED %s\n", sled->cdev.name);
+ }
+
+ return 0;
+}
+device_initcall(syscon_leds_init);