1 files changed, 399 insertions, 0 deletions
diff --git a/target/linux/ubicom32/files/drivers/video/backlight/ubicom32bl.c b/target/linux/ubicom32/files/drivers/video/backlight/ubicom32bl.c
new file mode 100644
index 000000000..99538c341
--- /dev/null
+++ b/target/linux/ubicom32/files/drivers/video/backlight/ubicom32bl.c
@@ -0,0 +1,399 @@
+/*
+ * drivers/video/backlight/ubicom32bl.c
+ *	Backlight driver for the Ubicom32 platform
+ *
+ * (C) Copyright 2009, Ubicom, Inc.
+ *
+ * This file is part of the Ubicom32 Linux Kernel Port.
+ *
+ * The Ubicom32 Linux Kernel Port 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.
+ *
+ * The Ubicom32 Linux Kernel Port 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 the Ubicom32 Linux Kernel Port.  If not,
+ * see <http://www.gnu.org/licenses/>.
+ *
+ * Ubicom32 implementation derived from (with many thanks):
+ *   arch/m68knommu
+ *   arch/blackfin
+ *   arch/parisc
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/backlight.h>
+#include <linux/fb.h>
+
+#include <asm/ubicom32bl.h>
+#include <asm/ip5000.h>
+
+#define DRIVER_NAME			"ubicom32bl"
+#define UBICOM32BL_MAX_BRIGHTNESS	255
+
+struct ubicom32bl_data {
+	/*
+	 * Pointer to the platform data structure.  Keep this around since we need values
+	 * from it to set the backlight intensity.
+	 */
+	const struct ubicom32bl_platform_data	*pdata;
+
+	/*
+	 * Backlight device, we have to save this for use when we remove ourselves.
+	 */
+	struct backlight_device			*bldev;
+
+	/*
+	 * Current intensity, used for get_intensity.
+	 */
+	int					cur_intensity;
+
+	/*
+	 * Init function for PWM
+	 */
+	int (*init_fn)(struct ubicom32bl_data *);
+
+	/*
+	 * Set intensity function depending on the backlight type
+	 */
+	int (*set_intensity_fn)(struct ubicom32bl_data *, int);
+};
+
+/*
+ * ubicom32bl_set_intensity_gpio
+ */
+static int ubicom32bl_set_intensity_gpio(struct ubicom32bl_data *ud, int intensity)
+{
+	ud->cur_intensity = intensity ? 255 : 0;
+
+	if (intensity) {
+		// set gpio
+		return 0;
+	}
+
+	// clear gpio
+	return 0;
+}
+
+/*
+ * ubicom32bl_set_intensity_hw
+ */
+static int ubicom32bl_set_intensity_hw(struct ubicom32bl_data *ud, int intensity)
+{
+	u16_t period = ud->pdata->pwm_period;
+	u16_t duty;
+
+	/*
+	 * Calculate the new duty cycle
+	 */
+	duty = (period * intensity) / (UBICOM32BL_MAX_BRIGHTNESS + 1);
+
+	/*
+	 * Set the new duty cycle
+	 */
+	switch (ud->pdata->pwm_channel) {
+	case 0:
+		/*
+		 * Channel 0 is in the lower half of PORT C ctl0 and ctl1
+		 */
+		UBICOM32_IO_PORT(RC)->ctl1 = (ud->pdata->pwm_period << 16) | duty;
+		break;
+
+	case 1:
+		/*
+		 * Channel 1 is in the upper half of PORT C ctl0 and ctl2
+		 */
+		UBICOM32_IO_PORT(RC)->ctl2 = (ud->pdata->pwm_period << 16) | duty;
+		break;
+
+	case 2:
+		/*
+		 * Channel 2 is in PORT H ctl0 and ctl1
+		 */
+		UBICOM32_IO_PORT(RH)->ctl1 = (ud->pdata->pwm_period << 16) | duty;
+		break;
+	}
+
+	ud->cur_intensity = intensity;
+
+	return 0;
+}
+
+/*
+ * ubicom32bl_set_intensity
+ */
+static int ubicom32bl_set_intensity(struct backlight_device *bd)
+{
+	struct ubicom32bl_data *ud = (struct ubicom32bl_data *)bl_get_data(bd);
+	int intensity = bd->props.brightness;
+
+	/*
+	 * If we're blanked the the intensity doesn't matter.
+	 */
+	if ((bd->props.power != FB_BLANK_UNBLANK) || (bd->props.fb_blank != FB_BLANK_UNBLANK)) {
+		intensity = 0;
+	}
+
+	/*
+	 * Check for inverted backlight.
+	 */
+	if (ud->pdata->invert) {
+		intensity = UBICOM32BL_MAX_BRIGHTNESS - intensity;
+	}
+
+	if (ud->set_intensity_fn) {
+		return ud->set_intensity_fn(ud, intensity);
+	}
+
+	return -ENXIO;
+}
+
+/*
+ * ubicom32bl_get_intensity
+ *	Return the current intensity of the backlight.
+ */
+static int ubicom32bl_get_intensity(struct backlight_device *bd)
+{
+	struct ubicom32bl_data *ud = (struct ubicom32bl_data *)bl_get_data(bd);
+
+	return ud->cur_intensity;
+}
+
+/*
+ * ubicom32bl_init_hw_pwm
+ *	Set the appropriate PWM registers
+ */
+static int ubicom32bl_init_hw_pwm(struct ubicom32bl_data *ud)
+{
+	/*
+	 * bit 13: enable
+	 */
+	u16_t pwm_cfg = (1 << 13) | (ud->pdata->pwm_prescale << 8) ;
+
+	switch (ud->pdata->pwm_channel) {
+	case 0:
+		/*
+		 * Channel 0 is in the lower half of PORT C ctl0 and ctl1 (PA5)
+		 */
+		UBICOM32_IO_PORT(RC)->ctl0 &= ~0xFFFF;
+		UBICOM32_IO_PORT(RC)->ctl0 |= pwm_cfg;
+		UBICOM32_IO_PORT(RC)->ctl1 = ud->pdata->pwm_period << 16;
+
+		/*
+		 * If the port function is not set, set it to GPIO/PWM
+		 */
+		if (!UBICOM32_IO_PORT(RA)->function) {
+			UBICOM32_IO_PORT(RA)->function = 3;
+		}
+		break;
+
+	case 1:
+		/*
+		 * Channel 1 is in the upper half of PORT C ctl0 and ctl2 (PE4)
+		 */
+		UBICOM32_IO_PORT(RC)->ctl0 &= ~0xFFFF0000;
+		UBICOM32_IO_PORT(RC)->ctl0 |= (pwm_cfg << 16);
+		UBICOM32_IO_PORT(RC)->ctl2 = ud->pdata->pwm_period << 16;
+
+		/*
+		 * If the port function is not set, set it to GPIO/ExtIOInt
+		 */
+		if (!UBICOM32_IO_PORT(RE)->function) {
+			UBICOM32_IO_PORT(RE)->function = 3;
+		}
+		break;
+
+	case 2:
+		/*
+		 * Channel 2 is in PORT H ctl0 and ctl1 (PD0)
+		 */
+		UBICOM32_IO_PORT(RH)->ctl0 &= ~0xFFFF0000;
+		UBICOM32_IO_PORT(RH)->ctl0 = pwm_cfg;
+		UBICOM32_IO_PORT(RH)->ctl1 = ud->pdata->pwm_period << 16;
+
+		/*
+		 * If the port function is not set, set it to GPIO
+		 */
+		if (!UBICOM32_IO_PORT(RD)->function) {
+			UBICOM32_IO_PORT(RD)->function = 3;
+		}
+		break;
+	}
+
+	return 0;
+}
+
+/*
+ * ubicom32bl_init_gpio
+ *	Allocate the appropriate GPIO
+ */
+static int ubicom32bl_init_gpio(struct ubicom32bl_data *ud)
+{
+	return 0;
+}
+
+static struct backlight_ops ubicom32bl_ops = {
+	.get_brightness = ubicom32bl_get_intensity,
+	.update_status  = ubicom32bl_set_intensity,
+};
+
+/*
+ * ubicom32bl_probe
+ */
+static int ubicom32bl_probe(struct platform_device *pdev)
+{
+	const struct ubicom32bl_platform_data *pdata = pdev->dev.platform_data;
+	struct ubicom32bl_data *ud;
+	struct backlight_device *bldev;
+	int retval;
+
+	/*
+	 * Check to see if we have any platform data, if we don't then the backlight is not
+	 * configured on this device.
+	 */
+	if (!pdata) {
+		return -ENODEV;
+	}
+
+	/*
+	 * Allocate our private data
+	 */
+	ud = kzalloc(sizeof(struct ubicom32bl_data), GFP_KERNEL);
+	if (!ud) {
+		return -ENOMEM;
+	}
+
+	ud->pdata = pdata;
+
+	/*
+	 * Check to see that the platform data is valid for this driver
+	 */
+	switch (pdata->type) {
+	case UBICOM32BL_TYPE_PWM:
+		{
+			/*
+			 * Make sure we have a PWM peripheral
+			 */
+			u32_t chipid;
+			asm volatile (
+				"move.4         %0, CHIP_ID     \n\t"
+				: "=r" (chipid)
+			);
+			if (chipid != 0x00030001) {
+				retval = -ENODEV;
+				goto fail;
+			}
+
+			if (pdata->pwm_channel > 3) {
+				retval = -ENODEV;
+				goto fail;
+			}
+			if (pdata->pwm_prescale > 16) {
+				retval = -EINVAL;
+				goto fail;
+			}
+
+			ud->init_fn = ubicom32bl_init_hw_pwm;
+			ud->set_intensity_fn = ubicom32bl_set_intensity_hw;
+			break;
+		}
+
+	case UBICOM32BL_TYPE_PWM_HRT:
+		// For now, PWM HRT devices are treated as binary lights.
+
+	case UBICOM32BL_TYPE_BINARY:
+		ud->init_fn = ubicom32bl_init_gpio;
+		ud->set_intensity_fn = ubicom32bl_set_intensity_gpio;
+		break;
+	}
+
+	/*
+	 * Register our backlight device
+	 */
+	bldev = backlight_device_register(DRIVER_NAME, &pdev->dev, ud, &ubicom32bl_ops);
+	if (IS_ERR(bldev)) {
+		retval = PTR_ERR(bldev);
+		goto fail;
+	}
+
+	ud->bldev = bldev;
+	ud->cur_intensity = pdata->default_intensity;
+	platform_set_drvdata(pdev, ud);
+
+	/*
+	 * Start up the backlight at the prescribed default intensity
+	 */
+	bldev->props.power = FB_BLANK_UNBLANK;
+	bldev->props.max_brightness = UBICOM32BL_MAX_BRIGHTNESS;
+	bldev->props.brightness = pdata->default_intensity;
+
+	if (ud->init_fn) {
+		if (ud->init_fn(ud) != 0) {
+			retval = -ENODEV;
+			backlight_device_unregister(ud->bldev);
+			goto fail;
+		}
+	}
+	ubicom32bl_set_intensity(bldev);
+
+	printk(KERN_INFO DRIVER_NAME ": Backlight driver started\n");
+
+	return 0;
+
+fail:
+	platform_set_drvdata(pdev, NULL);
+	kfree(ud);
+	return retval;
+}
+
+/*
+ * ubicom32bl_remove
+ */
+static int __exit ubicom32bl_remove(struct platform_device *pdev)
+{
+	struct ubicom32bl_data *ud = platform_get_drvdata(pdev);
+
+	backlight_device_unregister(ud->bldev);
+	platform_set_drvdata(pdev, NULL);
+	kfree(ud);
+
+	return 0;
+}
+
+static struct platform_driver ubicom32bl_driver = {
+	.driver = {
+		.name = DRIVER_NAME,
+		.owner = THIS_MODULE,
+	},
+
+	.remove = __exit_p(ubicom32bl_remove),
+};
+
+/*
+ * ubicom32bl_init
+ */
+static int __init ubicom32bl_init(void)
+{
+	return platform_driver_probe(&ubicom32bl_driver, ubicom32bl_probe);
+}
+module_init(ubicom32bl_init);
+
+/*
+ * ubicom32bl_exit
+ */
+static void __exit ubicom32bl_exit(void)
+{
+	platform_driver_unregister(&ubicom32bl_driver);
+}
+module_exit(ubicom32bl_exit);
+
+MODULE_AUTHOR("Patrick Tjin <@ubicom.com>");
+MODULE_DESCRIPTION("Ubicom32 backlight driver");
+MODULE_LICENSE("GPL");