TI LMU backlight driver provides common driver features.
Chip specific configuration is handled by each backlight driver such like
LM3532, LM3631, LM3633, LM3695 and LM3697.
It supports common features as below.
- Consistent device control flow
- Control bank assignment from the platform data
- Backlight subsystem control
- PWM brightness control
- Shared device tree node
Cc: Jingoo Han <jg1.han@xxxxxxxxxxx>
Cc: Bryan Wu <cooloney@xxxxxxxxx>
Cc: Lee Jones <lee.jones@xxxxxxxxxx>
Signed-off-by: Milo Kim <milo.kim@xxxxxx>
---
drivers/video/backlight/Kconfig | 7 +
drivers/video/backlight/Makefile | 1 +
drivers/video/backlight/ti-lmu-backlight.c | 369 ++++++++++++++++++++++++++++
drivers/video/backlight/ti-lmu-backlight.h | 78 ++++++
4 files changed, 455 insertions(+)
create mode 100644 drivers/video/backlight/ti-lmu-backlight.c
create mode 100644 drivers/video/backlight/ti-lmu-backlight.h
diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index 5a3eb2e..3641698 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -384,6 +384,13 @@ config BACKLIGHT_LM3639
help
This supports TI LM3639 Backlight + 1.5A Flash LED Driver
+config TI_LMU_BACKLIGHT
+ tristate "Backlight driver for TI LMU"
+ depends on BACKLIGHT_LM3532 || BACKLIGHT_LM3631 || BACKLIGHT_LM3633 || BACKLIGHT_LM3695 || BACKLIGHT_LM3697
+ help
+ TI LMU backlight driver provides common driver features.
+ Chip specific configuration is handled by each backlight driver.
+
config BACKLIGHT_LP855X
tristate "Backlight driver for TI LP855X"
depends on BACKLIGHT_CLASS_DEVICE && I2C
diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index bb82002..f80e046 100644
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -39,6 +39,7 @@ obj-$(CONFIG_BACKLIGHT_HP700) += jornada720_bl.o
obj-$(CONFIG_BACKLIGHT_LM3533) += lm3533_bl.o
obj-$(CONFIG_BACKLIGHT_LM3630A) += lm3630a_bl.o
obj-$(CONFIG_BACKLIGHT_LM3639) += lm3639_bl.o
+obj-$(CONFIG_TI_LMU_BACKLIGHT) += ti-lmu-backlight.o
obj-$(CONFIG_BACKLIGHT_LOCOMO) += locomolcd.o
obj-$(CONFIG_BACKLIGHT_LP855X) += lp855x_bl.o
obj-$(CONFIG_BACKLIGHT_LP8788) += lp8788_bl.o
diff --git a/drivers/video/backlight/ti-lmu-backlight.c b/drivers/video/backlight/ti-lmu-backlight.c
new file mode 100644
index 0000000..5ceb5e8
--- /dev/null
+++ b/drivers/video/backlight/ti-lmu-backlight.c
@@ -0,0 +1,369 @@
+/*
+ * TI LMU Backlight Common Driver
+ *
+ * Copyright 2014 Texas Instruments
+ *
+ * Author: Milo Kim <milo.kim@xxxxxx>
+ *
+ * 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.
+ *
+ * LMU backlight driver supports common features as below.
+ *
+ * - Consistent device control flow by using ti_lmu_bl_ops
+ * - Control bank assignment from the platform data
+ * - Backlight subsystem control
+ * - PWM brightness control
+ * - Shared device tree node
+ *
+ * Sequence of LMU backlight control
+ *
+ * (Chip dependent backlight driver) (TI LMU Backlight Common)
+ *
+ * Operation configuration
+ * ti_lmu_backlight_init_device() --->
+ * Initialization <--- ops->init()
+ *
+ * ti_lmu_backlight_register() --->
+ * Backlight configuration <--- ops->configure()
+ *
+ * Runtime brightness control
+ * Enable register control <--- ops->bl_enable()
+ * Brightness register control <--- ops->update_brightness()
+ *
+ */
+
+#include <linux/backlight.h>
+#include <linux/err.h>
+#include <linux/mfd/ti-lmu.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/slab.h>
+
+#include "ti-lmu-backlight.h"
+
+#define DEFAULT_BL_NAME "lcd-backlight"
+
+static int ti_lmu_backlight_enable(struct ti_lmu_bl *lmu_bl, int enable)
+{
+ const struct ti_lmu_bl_ops *ops = lmu_bl->chip->ops;
+
+ if (ops->bl_enable)
+ return ops->bl_enable(lmu_bl, enable);
+
+ return 0;
+}
+
+static void ti_lmu_backlight_pwm_ctrl(struct ti_lmu_bl *lmu_bl, int br,
+ int max_br)
+{
+ struct pwm_device *pwm;
+ unsigned int duty, period;
+
+ /* Request a PWM device with the consumer name */
+ if (!lmu_bl->pwm) {
+ pwm = devm_pwm_get(lmu_bl->chip->dev, lmu_bl->pwm_name);
+ if (IS_ERR(pwm)) {
+ dev_err(lmu_bl->chip->dev,
+ "Can not get PWM device: %s\n",
+ lmu_bl->pwm_name);
+ return;
+ }
+ lmu_bl->pwm = pwm;
+ }
+
+ period = lmu_bl->bl_pdata->pwm_period;
+ duty = br * period / max_br;
+
+ pwm_config(lmu_bl->pwm, duty, period);
+ if (duty)
+ pwm_enable(lmu_bl->pwm);
+ else
+ pwm_disable(lmu_bl->pwm);
+}
+
+static int ti_lmu_backlight_update_status(struct backlight_device *bl_dev)
+{
+ struct ti_lmu_bl *lmu_bl = bl_get_data(bl_dev);
+ const struct ti_lmu_bl_ops *ops = lmu_bl->chip->ops;
+ int ret = 0;
+ int brt;
+
+ if (bl_dev->props.state & BL_CORE_SUSPENDED)
+ bl_dev->props.brightness = 0;
+
+ brt = bl_dev->props.brightness;
+ if (brt > 0)
+ ret = ti_lmu_backlight_enable(lmu_bl, 1);
+ else
+ ret = ti_lmu_backlight_enable(lmu_bl, 0);
+
+ if (ret)
+ return ret;
+
+ if (lmu_bl->mode == BL_PWM_BASED)
+ ti_lmu_backlight_pwm_ctrl(lmu_bl, brt,
+ bl_dev->props.max_brightness);
+
+ /*
+ * In some devices, additional handling is required after PWM control.
+ * So, just call device-specific brightness function.
+ */
+ if (ops->update_brightness)
+ return ops->update_brightness(lmu_bl, brt);
+
+ return 0;
+}
+
+static int ti_lmu_backlight_get_brightness(struct backlight_device *bl_dev)
+{
+ return bl_dev->props.brightness;
+}
+
+static const struct backlight_ops lmu_bl_common_ops = {
+ .options = BL_CORE_SUSPENDRESUME,
+ .update_status = ti_lmu_backlight_update_status,
+ .get_brightness = ti_lmu_backlight_get_brightness,
+};
+
+static int ti_lmu_backlight_parse_dt(struct device *dev, struct ti_lmu *lmu)
+{
+ struct ti_lmu_backlight_platform_data *pdata;
+ struct device_node *node = dev->of_node;
+ struct device_node *child;
+ int num_backlights;
+ int i = 0;
+ u8 imax_mA;
+
+ if (!node) {
+ dev_err(dev, "No device node exists\n");
+ return -ENODEV;
+ }
+
+ num_backlights = of_get_child_count(node);
+ if (num_backlights == 0) {
+ dev_err(dev, "No backlight strings\n");
+ return -EINVAL;
+ }
+
+ pdata = devm_kzalloc(dev, sizeof(*pdata) * num_backlights, GFP_KERNEL);
+ if (!pdata)
+ return -ENOMEM;
+
+ for_each_child_of_node(node, child) {
+ of_property_read_string(child, "bl-name", &pdata[i].name);
+
+ /* Make backlight strings */
+ pdata[i].bl_string = 0;
+ if (of_find_property(child, "hvled1-used", NULL))
+ pdata[i].bl_string |= LMU_HVLED1;
+ if (of_find_property(child, "hvled2-used", NULL))
+ pdata[i].bl_string |= LMU_HVLED2;
+ if (of_find_property(child, "hvled3-used", NULL))
+ pdata[i].bl_string |= LMU_HVLED3;
+
+ of_property_read_u8(child, "max-current-milliamp", &imax_mA);
+ pdata[i].imax = ti_lmu_get_current_code(imax_mA);
+
+ of_property_read_u8(child, "initial-brightness",
+ &pdata[i].init_brightness);
+
+ /* Light effect */
+ of_property_read_u32(child, "ramp-up", &pdata[i].ramp_up_ms);
+ of_property_read_u32(child, "ramp-down",
+ &pdata[i].ramp_down_ms);
+
+ /* PWM mode */
+ of_property_read_u32(child, "pwm-period", &pdata[i].pwm_period);
+
+ i++;
+ }
+
+ lmu->pdata->bl_pdata = pdata;
+ lmu->pdata->num_backlights = num_backlights;
+
+ return 0;
+}
+
+struct ti_lmu_bl_chip *
+ti_lmu_backlight_init_device(struct device *dev, struct ti_lmu *lmu,
+ const struct ti_lmu_bl_ops *ops)
+{
+ struct ti_lmu_bl_chip *chip;
+ int ret;
+
+ chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
+ if (!chip)
+ return ERR_PTR(-ENOMEM);
+
+ chip->dev = dev;
+ chip->lmu = lmu;
+ chip->ops = ops;
+
+ if (!lmu->pdata->bl_pdata) {
+ if (IS_ENABLED(CONFIG_OF))
+ ret = ti_lmu_backlight_parse_dt(dev, lmu);
+ else
+ return ERR_PTR(-ENODEV);
+
+ if (ret)
+ return ERR_PTR(ret);
+ }
+
+ if (chip->ops->init) {
+ ret = chip->ops->init(chip);
+ if (ret)
+ return ERR_PTR(ret);
+ }
+
+ return chip;
+}
+EXPORT_SYMBOL_GPL(ti_lmu_backlight_init_device);
+
+static void ti_lmu_backlight_set_ctrl_mode(struct ti_lmu_bl *lmu_bl)
+{
+ struct ti_lmu_backlight_platform_data *pdata = lmu_bl->bl_pdata;
+
+ if (pdata->pwm_period > 0)
+ lmu_bl->mode = BL_PWM_BASED;
+ else
+ lmu_bl->mode = BL_REGISTER_BASED;
+}
+
+static int ti_lmu_backlight_configure(struct ti_lmu_bl *lmu_bl)
+{
+ const struct ti_lmu_bl_ops *ops = lmu_bl->chip->ops;
+
+ if (ops->configure)
+ return ops->configure(lmu_bl);
+
+ return 0;
+}
+
+static int ti_lmu_backlight_add_device(struct ti_lmu_bl *lmu_bl)
+{
+ struct backlight_device *bl_dev;
+ struct backlight_properties props;
+ struct ti_lmu_backlight_platform_data *pdata = lmu_bl->bl_pdata;
+ int max_brightness = lmu_bl->chip->ops->max_brightness;
+ char name[20];
+
+ memset(&props, 0, sizeof(struct backlight_properties));
+ props.type = BACKLIGHT_PLATFORM;
+ props.brightness = pdata ? pdata->init_brightness : 0;
+ props.max_brightness = max_brightness;
+
+ /* Backlight device name */
+ if (!pdata->name)
+ snprintf(name, sizeof(name), "%s:%d", DEFAULT_BL_NAME,
+ lmu_bl->bank_id);
+ else
+ snprintf(name, sizeof(name), "%s", pdata->name);
+
+ bl_dev = backlight_device_register(name, lmu_bl->chip->dev, lmu_bl,
+ &lmu_bl_common_ops, &props);
+ if (IS_ERR(bl_dev))
+ return PTR_ERR(bl_dev);
+
+ lmu_bl->bl_dev = bl_dev;
+
+ return 0;
+}
+
+struct ti_lmu_bl *
+ti_lmu_backlight_register(struct ti_lmu_bl_chip *chip,
+ struct ti_lmu_backlight_platform_data *pdata,
+ int num_backlights)
+{
+ struct ti_lmu_bl *lmu_bl, *each;
+ int i, ret;
+
+ lmu_bl = devm_kzalloc(chip->dev, sizeof(*lmu_bl) * num_backlights,
+ GFP_KERNEL);
+ if (!lmu_bl)
+ return ERR_PTR(-ENOMEM);
+
+ for (i = 0; i < num_backlights; i++) {
+ each = lmu_bl + i;
+ each->bank_id = i;
+ each->chip = chip;
+ each->bl_pdata = pdata + i;
+
+ ti_lmu_backlight_set_ctrl_mode(lmu_bl);
+
+ ret = ti_lmu_backlight_configure(each);
+ if (ret) {
+ dev_err(chip->dev, "Backlight config err: %d\n", ret);
+ goto err;
+ }
+
+ ret = ti_lmu_backlight_add_device(each);
+ if (ret) {
+ dev_err(chip->dev, "Backlight device err: %d\n", ret);
+ goto cleanup_backlights;
+ }
+
+ backlight_update_status(each->bl_dev);
+ }
+
+ chip->num_backlights = num_backlights;
+
+ return lmu_bl;
+
+cleanup_backlights:
+ while (--i >= 0) {
+ each = lmu_bl + i;
+ backlight_device_unregister(each->bl_dev);
+ }
+err:
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(ti_lmu_backlight_register);
+
+int ti_lmu_backlight_unregister(struct ti_lmu_bl *lmu_bl)
+{
+ struct ti_lmu_bl *each;
+ struct backlight_device *bl_dev;
+ int num_backlights = lmu_bl->chip->num_backlights;
+ int i;
+
+ for (i = 0; i < num_backlights; i++) {
+ each = lmu_bl + i;
+
+ bl_dev = each->bl_dev;
+ bl_dev->props.brightness = 0;
+ backlight_update_status(bl_dev);
+ backlight_device_unregister(bl_dev);
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(ti_lmu_backlight_unregister);
+
+/*
+ * This callback function is invoked in case the LMU effect driver is
+ * requested successfully.
+ */
+void ti_lmu_backlight_effect_callback(struct ti_lmu_effect *lmu_effect,
+ int req_id, void *data)
+{
+ struct ti_lmu_bl *lmu_bl = data;
+ unsigned int ramp_time;
+
+ if (req_id == BL_EFFECT_RAMPUP)
+ ramp_time = lmu_bl->bl_pdata->ramp_up_ms;
+ else if (req_id == BL_EFFECT_RAMPDN)
+ ramp_time = lmu_bl->bl_pdata->ramp_down_ms;
+ else
+ return;
+
+ ti_lmu_effect_set_ramp(lmu_effect, ramp_time);
+}
+EXPORT_SYMBOL_GPL(ti_lmu_backlight_effect_callback);
+
+MODULE_DESCRIPTION("TI LMU Backlight Common Driver");
+MODULE_AUTHOR("Milo Kim");
+MODULE_LICENSE("GPL");
diff --git a/drivers/video/backlight/ti-lmu-backlight.h b/drivers/video/backlight/ti-lmu-backlight.h
new file mode 100644
index 0000000..7dd2fa5d
--- /dev/null
+++ b/drivers/video/backlight/ti-lmu-backlight.h
@@ -0,0 +1,78 @@
+/*
+ * TI LMU Backlight Common Driver
+ *
+ * Copyright 2014 Texas Instruments
+ *
+ * Author: Milo Kim <milo.kim@xxxxxx>
+ *
+ * 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.
+ *
+ */
+
+#ifndef __TI_LMU_BACKLIGHT_H__
+#define __TI_LMU_BACKLIGHT_H__
+
+#include <linux/mfd/ti-lmu.h>
+#include <linux/mfd/ti-lmu-effect.h>
+
+#define LMU_BL_DEFAULT_PWM_NAME "lmu-backlight"
+
+enum ti_lmu_bl_ctrl_mode {
+ BL_REGISTER_BASED,
+ BL_PWM_BASED,
+};
+
+struct ti_lmu_bl;
+struct ti_lmu_bl_chip;
+
+/*
+ * struct ti_lmu_bl_ops
+ * @init: Device specific initialization
+ * @configure: Device specific string configuration
+ * @update_brightness: Device specific brightness control
+ * @bl_enable: Device specific backlight enable/disable control
+ * @max_brightness: Max brightness value of backlight device
+ */
+struct ti_lmu_bl_ops {
+ int (*init)(struct ti_lmu_bl_chip *lmu_chip);
+ int (*configure)(struct ti_lmu_bl *lmu_bl);
+ int (*update_brightness)(struct ti_lmu_bl *lmu_bl, int brightness);
+ int (*bl_enable)(struct ti_lmu_bl *lmu_bl, int enable);
+ const int max_brightness;
+};
+
+/* One backlight chip can have multiple backlight strings */
+struct ti_lmu_bl_chip {
+ struct device *dev;
+ struct ti_lmu *lmu;
+ const struct ti_lmu_bl_ops *ops;
+ int num_backlights;
+};
+
+/* Backlight string structure */
+struct ti_lmu_bl {
+ int bank_id;
+ struct backlight_device *bl_dev;
+ struct ti_lmu_bl_chip *chip;
+ struct ti_lmu_backlight_platform_data *bl_pdata;
+ enum ti_lmu_bl_ctrl_mode mode;
+ struct pwm_device *pwm;
+ char pwm_name[20];
+};
+
+struct ti_lmu_bl_chip *
+ti_lmu_backlight_init_device(struct device *dev, struct ti_lmu *lmu,
+ const struct ti_lmu_bl_ops *ops);
+
+struct ti_lmu_bl *
+ti_lmu_backlight_register(struct ti_lmu_bl_chip *chip,
+ struct ti_lmu_backlight_platform_data *pdata,
+ int num_backlights);
+
+int ti_lmu_backlight_unregister(struct ti_lmu_bl *lmu_bl);
+
+void ti_lmu_backlight_effect_callback(struct ti_lmu_effect *lmu_effect,
+ int req_id, void *data);
+#endif
--
1.7.9.5
--
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