backlight: Add RAVE SP backlight driver

This driver provides access to RAVE SP backlight control
functionality.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index 4e1d2ad50ba142950e0048d986ab7e0df2eafece..5d2d0d7e8100c4f4bb858468cd56a84fb379bc1c 100644 (file)
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -467,6 +467,12 @@ config BACKLIGHT_ARCXCNN
          If you have an ARCxCnnnn family backlight say Y to enable
          the backlight driver.
 
+config BACKLIGHT_RAVE_SP
+       tristate "RAVE SP Backlight driver"
+       depends on RAVE_SP_CORE
+       help
+         Support for backlight control on RAVE SP device.
+
 endif # BACKLIGHT_CLASS_DEVICE
 
 endif # BACKLIGHT_LCD_SUPPORT

diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index 5e28f01c839107ef8e9cca3225181f46b953545e..19da71d518bf306287e0d18ec987693def357268 100644 (file)
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -57,3 +57,4 @@ obj-$(CONFIG_BACKLIGHT_TOSA)          += tosa_bl.o
 obj-$(CONFIG_BACKLIGHT_TPS65217)       += tps65217_bl.o
 obj-$(CONFIG_BACKLIGHT_WM831X)         += wm831x_bl.o
 obj-$(CONFIG_BACKLIGHT_ARCXCNN)        += arcxcnn_bl.o
+obj-$(CONFIG_BACKLIGHT_RAVE_SP)                += rave-sp-backlight.o

diff --git a/drivers/video/backlight/rave-sp-backlight.c b/drivers/video/backlight/rave-sp-backlight.c
new file mode 100644 (file)
index 0000000..462f14a
--- /dev/null
+++ b/drivers/video/backlight/rave-sp-backlight.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+/*
+ * LCD Backlight driver for RAVE SP
+ *
+ * Copyright (C) 2018 Zodiac Inflight Innovations
+ *
+ */
+
+#include <linux/backlight.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mfd/rave-sp.h>
+#include <linux/platform_device.h>
+
+#define        RAVE_SP_BACKLIGHT_LCD_EN        BIT(7)
+
+static int rave_sp_backlight_update_status(struct backlight_device *bd)
+{
+       const struct backlight_properties *p = &bd->props;
+       const u8 intensity =
+               (p->power == FB_BLANK_UNBLANK) ? p->brightness : 0;
+       struct rave_sp *sp = dev_get_drvdata(&bd->dev);
+       u8 cmd[] = {
+               [0] = RAVE_SP_CMD_SET_BACKLIGHT,
+               [1] = 0,
+               [2] = intensity ? RAVE_SP_BACKLIGHT_LCD_EN | intensity : 0,
+               [3] = 0,
+               [4] = 0,
+       };
+
+       return rave_sp_exec(sp, cmd, sizeof(cmd), NULL, 0);
+}
+
+static const struct backlight_ops rave_sp_backlight_ops = {
+       .options        = BL_CORE_SUSPENDRESUME,
+       .update_status  = rave_sp_backlight_update_status,
+};
+
+static struct backlight_properties rave_sp_backlight_props = {
+       .type           = BACKLIGHT_PLATFORM,
+       .max_brightness = 100,
+       .brightness     = 50,
+};
+
+static int rave_sp_backlight_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct backlight_device *bd;
+
+       bd = devm_backlight_device_register(dev, pdev->name, dev->parent,
+                                           dev_get_drvdata(dev->parent),
+                                           &rave_sp_backlight_ops,
+                                           &rave_sp_backlight_props);
+       if (IS_ERR(bd))
+               return PTR_ERR(bd);
+
+       backlight_update_status(bd);
+
+       return 0;
+}
+
+static const struct of_device_id rave_sp_backlight_of_match[] = {
+       { .compatible = "zii,rave-sp-backlight" },
+       {}
+};
+
+static struct platform_driver rave_sp_backlight_driver = {
+       .probe = rave_sp_backlight_probe,
+       .driver = {
+               .name = KBUILD_MODNAME,
+               .of_match_table = rave_sp_backlight_of_match,
+       },
+};
+module_platform_driver(rave_sp_backlight_driver);
+
+MODULE_DEVICE_TABLE(of, rave_sp_backlight_of_match);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Andrey Vostrikov <andrey.vostrikov@cogentembedded.com>");
+MODULE_AUTHOR("Nikita Yushchenko <nikita.yoush@cogentembedded.com>");
+MODULE_AUTHOR("Andrey Smirnov <andrew.smirnov@gmail.com>");
+MODULE_DESCRIPTION("RAVE SP Backlight driver");

diff --git a/include/linux/mfd/rave-sp.h b/include/linux/mfd/rave-sp.h
index 796fb9794c9eb67cb55902697ae3d3b12621e59a..fe0ce7bc59cfa2948ed9ad15d0f7700af8f93d3a 100644 (file)
--- a/include/linux/mfd/rave-sp.h
+++ b/include/linux/mfd/rave-sp.h
@@ -21,6 +21,7 @@ enum rave_sp_command {
        RAVE_SP_CMD_STATUS                      = 0xA0,
        RAVE_SP_CMD_SW_WDT                      = 0xA1,
        RAVE_SP_CMD_PET_WDT                     = 0xA2,
+       RAVE_SP_CMD_SET_BACKLIGHT               = 0xA6,
        RAVE_SP_CMD_RESET                       = 0xA7,
        RAVE_SP_CMD_RESET_REASON                = 0xA8,